,Mf;"RLF 100 35fl Panama-Pacific Intern 1 ! Exposition Company Digitized by the Internet Archive in 2007 with funding from Microsoft Corporation http://www.archive.org/details/appliedasurgicalOOtrevrich MANUALS FOR STUDENTS OF MEDICINE Surgical Applied Anatomy BY SIR FREDERICK TREVES, Bart. G.C.V.O., C.B., LLD., F.R.G.S. Serjeant Surgeon to H.M. the King; Consulting Surgeon to the London Hospital ; late Lecturer on Anatomy at the London Hospital. SIXTH EDITION, REVISED BY ARTHUR KEITH, M.D., LL.D. Aber., F.R.G.S. Eng. Hunterian Professor and Conservator of the Museum. Royal College of Surgeons of England ; formerly Lecturer on and Senior Demonstrator of Anatomy at the London Hospital ; Examiner in the Universities of Aberdeen, Cambridge, etc. Illustrated with 137 Figures including 58 in colour LEA & PHILADELPHIA FEBIGER AND NEW Y O It K nM QM53I /9/2> PREFACE TO THE SIXTH EDITION Although many additions have been made to and minor alterations effected in the present edition, this book still retains the spirit, form, and size given to it by its distinguished Author. The chief alterations in the new edition relate to glands of internal secretion, to the lymphatic system, to the anatomy of the abdomen, and to new facts which have been discovered by the use of X-rays in examining the human body. Thirty-five new illustrations have been intro- duced, many of them in colour. In preparing new figures and in revising the text the Editor has been assisted by Dr. S. J. A. Beale. Arthur Keith. The Museum , Royal College of Surgeons of England. 8661 PREFACE TO THE FIRST EDITION Applied Anatomy has, I imagine, a twofold func- tion. On the one hand it serves to give a precise basis to those incidents and procedures in practice that more especially involve anatomical knowledge ; on the other hand it endues the dull items of that knowledge with meaning and interest by the aid of illustrations drawn from common medical and surgical experience. In this latter aspect it bears somewhat the same relation to Systematic Anatomy that a series of experiments in Physics bears to a treatise dealing with the bare data of that science. The student of Human Anatomy has often a nebulous notion that what he is learning will sometime prove of service to him ; and may be conscious also that the study is a valuable, if somewhat unexciting, mental exercise. Beyond these impressions he must regard his efforts as concerned merely in the accumulation of a number of hard, unassimilable facts. It should be one object of Applied Anatomy to invest these facts with the interest derived from an association with the circumstances of daily life ; it should make the dry bones live. It must be owned also that all details in Anatomy have not the same practical value, and that the memory of many of them may fade with- out loss to the competency of the practitioner in medicine or surgery. It should be one other object, therefore, of a book having such a purpose as the present, to assist the student in judging of the comparative value of the matter he has viii PREFACE learnt ; and should help him, when his recollection of anatomical facts grows dim, to encourage the survival of the fittest. In writing this manual I have endeavoured, so far as the space at my command would permit, to carry out the objects above described ; and while I believe that the chief matters usually dealt with in works on Surgical Anatomy have not been neglected, I have nevertheless tried to make the principle of the book the principle that under- lies Mr. Hilton's familiar lectures on " Rest and Pain." I have assumed that the reader has some know- ledge of Human Anatomy, and have not entered, except in a few instances, into any detailed anatomical descriptions. The bare accounts, for , example, of the regions concerned in Hernia I have left to the systematic treatises, and have dealt only with the bearings of the anatomy of the parts upon the circumstances of practice. The limits of space have compelled me to omit all those parts of the " Surgery of the Arteries " that deal with ligature, collateral circulation, abnor- malities, and the like. This omission I do not regret, since those subjects are fully treated not only in works on operative surgery, but also in the manuals of general anatomy. The book is intended mainly for the use of students preparing for their final examination in surgery. I hope, however, that it will be of use also to practitioners whose memory of their dissecting-room work is growing a little grey, and who would wish to recall such anatomical matters as have the most direct bearing upon the details of practice. Moreover, it is possible that junior students may find some interest in the volume, and ' may have their studies rendered more in- telligent by learning how anatomy is concerned in actual dealings with disease. Frederick Treves. September, 1883. CONTENTS PART I.-THE HEAD AND NECK CHAPTER PAGR 1. The Scalp 1 2. The Bony 'Vault of the Cranium ... 17 3. The Cranial Contents 31 4. The Orbit and Eye . . . . .50 5. The Ear 82 <;. The Nose and Nasal Cavities .... 98 7. The Face 116 8. The Mouth. Tongue, Palate, and Pharynx . 143 9. The Neck 165 PART IL-THE THORAX 10. The Chest and its Viscera . 203 PART III -THE UPPER EXTREMITY 11. The Region of the Shoulder .... 224 12. The Arm ,264 13. The Region of the Elbow .... 272 14. The Forearm 291 15. The Wrist and Hand 300 x CONTENTS PART IV.-THE ABDOMEN AND THE PELVIS OHAPTKtt PAGE 16. The Abdomen 332 17. The Abdominal Viscera 371 18. The Abdominal Viscera {concluded) . .414 19. The Pelvis . 445 20. The Perineum 455 PART V -THE LOWER EXTREMITY 21. The Region of the Hip 502 22. The Thigh 540 23. The Region of the Knee 548 24. The Leg 570 25. The Ankle and the Foot 587 PART VI.-THE SPINE AND SPINAL CORD 25. The Spine 627 27. The Spinal Cord .638 INDEX 653 Surgical Applied Anatomy p ART i._ the head and neck CHAPTER I THE SCALP The soft parts covering: the vault of the skull may be divided into five layers : (1) the skin, (2) the subcutaneous fatty tissue, (3) the occipito-frontalis muscle and its aponeurosis, (4) the subaponeurotic connective tissue, and (5) the pericranium. It is convenient to consider the term " scalp " as limited to the structure formed by the union of the first three layers above named The skin of the scalp is thicker than m any other part of the body. It is in all parts in- timately adherent, by means of the subcutaneous tissue, to the aponeurosis and muscle beneath it, and, from this adhesion, it follows that the skin moves in all movements of that muscle. The sub- cutaneous tissue is, like a similar tissue in the palm, admirably constructed to resist pressure, being composed of a multitude of fibrous bands enclosing fat lobules in more or less isolated spaces (Fig. 1, b). ^ The density of the scalp is such, that in surface inflammations, such as cutaneous ery- sipelas, it is unable to present (except in a very slight degree) two conspicuous features of such inflammations, viz. redness and swelling. The skin B THE HEAD AND NECK [Chap. is provided with a great number of sebaceous glands, which may develop into cystic tumours or wens, such cysts being more common upon the scalp than in any other part of the body. Being skin growths, these cysts, even when large, remain, ex- — C6 — h c ■ — a ■--/ —3 — k -Diagram showing the layers of the scalp and membranes of the brain in section. a, Skin ; b, subcutaneous tissue with hair roots and vessels : <\ epi- cranium ; d, subaponeurotic layer ; c, pericranium ; /, parietal bone; g, dura mater; A - , arachnoid; Z, pia mater; m, cortex ; w, in subdural space near a Pacchionian body projecting within the superior longitudinal sinus, cept in rare instances, entirely outside the apo- neurosis, and can therefore be removed without risk of opening up the area of loose connective tissue between the aponeurosis and the peri- cranium. There being no fatty tissue in any of the layers I] THE SCALP 3 that cover the bony vault save in the subcutaneous layer, it happens that in cases of obesity the scalp undergoes but little change, the fat in the subcu- taneous tissue being limited by the dense fibrous structures that enclose it. For the same reasons fatty tumours of the scalp are very rare. The attachment of the hairs collectively to the scalp is so strong that there are many cases where the entire weight of the body has been supported by the hair of the scalp. Agnew records the case of a woman whose hair became entangled in the re- volving shaft of a machine. The hair did not give way, but the entire scalp was torn off from the skull. The patient recovered. Dangerous area of the scalp. — Between the aponeurosis and the pericranium is an exten- sive layer of loose connective tissue, that may, for reasons to be presently given, be fairly called the dangerous area of the scalp (Fig. 1, d). The mobility of the scalp depends entirely upon the laxity of this layer of tissue. In extensive scalp wounds, when a part of the scalp is separated in the form of a large flap, a flap that may hang down and cover half the face, it is the very loose- ness of this tissue that permits such separation. In the Indian process of scalping, a taste that is becoming one of the past, the much-prized piece of skin is torn from the skull through this lax area of connective tissue, and, were there no such area, scalping would be an operation requiring some time and art. The exposure of the skull in a post-mortem examination is effected by peeling off the scalp along this layer of loose tissue, and it is remark- able with what ease the- skull can be exposed by this manoeuvre. Wounds of the scalp never gape, unless the wound has involved the scalp muscle or its apo- neurosis. When this structure has been divided the lax layer beyond permits of great separation of the edgesof even the simplest wounds. In uncom- plicated incised wounds, the amount of gaping of I THE HEAD AND NECK [Chap. the cut depends upon the action of the occipito- frontal muscle. Those wounds gape the most that are made across the muscle itself, and that are transverse to the direction of its fibres, while those show the least separation that involve the aponeurosis and are made in an antero-posterior direction. The mobility of the scalp is more marked in the young tiian in the old. A case recorded by Agnew serves in a strange degree to illustrate this fact in the person of an infant. A midwife attending a woman in labour mistook the scalp of the infant for the membranes, and gashed it with a pair of scissors. Labour pains came on and the head was protruded through the scalp wound, so that the whole vault of the skull was peeled like an orange. The scalp being firmly stretched over the hard cranium beneath, it follows that contused wounds often appear as cleanly cut as are those that have been made by an incision. Such wounds may be compared to the clean cut that may be made in a kid glove when it is tightly stretched over the knuckles and those parts are sharply rapped. The scalp is extremely vascular, and presents therefore a great resistance to sloughing and gan- grenous conditions. Large flaps of a lacerated scalp, even when extensively separated and almost cut off from the rest of the iiead, are more prone to live than to die. A like flap of skin, separated from other parts of the surface, would most prob- ably perish ; but the scalp has this advantage, that the vessels run practically in the skin itself, or are, at least, in the tissue beyond the aponeurosis (Fig. 1). Thus, when a scalp flap is torn up, it still carries with it a very copious blood supply. Bleeding from these wounds is usually very free, and often difficult to arrest. This depends not so much upon the number of vessels in the part as upon the density of the tissue through which these vessels run, the * adherence of the outer arterial wall to the scalp structure, and the inability, therefore, of the artery to retract properly when I] THE PERICRANIUM 5 divided. For the same reason it is almost im- possible to pick up an artery divided in a scalp wound. The bleeding is checked by a hare-lip pin or by pressure. In all parts of the body where a dense bone is covered by a comparatively thin layer of soft tis- sues, sloughing of those tissues is apt to be in- duced by long and severe pressure. The scalp, by its vascularity, is saved to a great extent from this evil, and is much less liable to slough than are the soft parts covering such bones as the con- dyles of the humerus or the sacrum. But such an effect is sometimes produced, as in a case I saw, where the tissues over the frontal and occipital regions sloughed from the continued application of a tight bandage put on to arrest bleeding from a frontal wound. The pericranium is but slightly adherent to the bone, except at the sutures, where it is inti- mately united (Fig. 1, e). In lacerated wounds this membrane can be readily stripped from the skull, and often, in these injuries, extensive tracts of bone are laid bare. The pericranium differs somewhat in its functions from the periosteum that covers other bones. If the periosteum be removed to any extent from a bone, the part from whence it is removed will very o probably perish, and necrosis from deficient blood supply result. But the pericranium may be stripped off a con- siderable part of the skull vault without any necrosis, save perhaps a ^little superficial ex- foliation. This is explained by the fact that the cranial bones derive their blood supply mainly from the dura mater, and are therefore to a considerable extent independent of the pericranium. A like independence cannot be claimed for the periosteum covering other bones, since that membrane brings to the part it covers a very copious and essential contribution to its blood supply. This disposition of the pericran- ium is also well illustrated by its action in cases of necrosis of the cranial bones. In necrosis of a 6 THE HEAD AND NECK [Chap. long bone, the separation of the sequestrum is attended with a vigorous periosteal growth of new bone, which repairs the gap left after the re- moval of such sequestra. In necrosis of the vault of the skull, however, no new bone is formed, as a rule, and the gap remains unrepaired. The general indisposition of the pericranium to form new bone in other circumstances is frequently illustrated. Abscesses in the scalp region may be situated (1) above the aponeurosis, (2) between the apo- neurosis and the pericranium, and (3) beneath the pericranium. Abscesses in the first situation must always be small and comparatively insignificant, since the density of the scalp tissue here is such that suppuration can only extend with the greatest difficulty. Suppuration, however, in the second situation (in the loose tissue beneath the aponeurosis) may prove very serious. The laxity of this tissue offers every inducement to the ab- scess to extend when once pus has found its way between the aponeurosis and the pericranium. Suppuration in this area may undermine the en- tire scalp, which in severe and unrelieved cases may rest upon the abscess beneath as upon a kind of water-bed. As in scalp wounds, the aponeu- rosis is often divided, and as suppuration may follow the injury, it will be seen that the chief danger of those lesions depends upon the spread- ing of such suppuration to the area of lax con- nective tissue now under notice. _ The significance of a small amount of bare bone in a scalp wound is not so much that evils will happen to the bone, but that the aponeurosis has been certainly divided, and the dangerous area of the scalp opened up. Suppuration, when it occurs in this area, is only limited by the attachments of the occipito-frontalis muscle and its aponeurosis, and therefore the most dependent places through which pus can be evacuated are situated along a line drawn round the head, commencing in front, above the eyebrow, passing at the side a little above the II ELEMATOMATA OF THE SCALP 7 zygoma, and ending behind at the superior curved line of the occipital bone. The scalp, even when extensively dissected up by such abscesses, does not perish, since it carries, as above explained, its blood supply with it. The abscess is often very slow to close, since its walls are prevented from obtaining perfect rest by the frequent movement of the epicranial muscle. To mitigate this evil, and to ensure closing of the sinuses in obstinate cases, Mr. Hilton advises that the whole scalp be firmly secured by strapping, so that the movement of the muscle is arrested. Abscesses beneath the pericranium must be limited to one bone, since the dipping-in of the membrane at the sutures prevents a more exten- sive spreading of the suppuration. Ilseniatomata, or blood tumours, of the scalp region occur in the same localities as ab- scesses. The extravasation of blood above the apo- neurosis must be of a limited character, while that beneath it may be very extensive. It fortunately happens, however, that the cellular tissue between the aponeurosis and the pericranium contains but very few vessels, and hence large extravasations in this tissue are uncommon. Extravasations of blood beneath the peri- cranium are generally termed cephalhsematomata, and are of necessity limited to one bone. They are usually congenital, are due to pressure upon the head at birth, and are thus most commonly found over one parietal bone, that bone being probably the one most exposed to pressure. Their greater frequency in male children may depend upon the larger size of the head in the male foetus. Such extravasations in early life are encouraged by the laxity of the pericranium, and by the soft- ness and vascularity of the subjacent bone. In the temporal region, or the region corre- sponding to the temporal muscle, the layers of soft parts between the skin and the bone are some- what different from those that have been already described as common to the chief parts of the scalp. 8 THE HEAD AND NECK [Chap. There is a good deal of fat in the temporal fossa, and when this is absorbed it leads to more or less prominence of the zygoma and malar bone, and so produces the projecting "cheek bones " of the emaciated. The temporal muscle above the zy- goma is covered in by a very dense fascia, the temporal fascia, which is attached above to the temporal ridge on the frontal and parietal bones, and below to the zygomatic arch. The unyielding nature of this fascia is well illustrated by a case recorded by Denonvilliers. It concerned a woman who had fallen in the street, and was ad- mitted into hospital with a deep wound in the temporal region. A piece of bone of several lines in length was found loose at the bottom of the wound, and was removed. After its removal the finger could be passed through an opening with an unyielding border, and came in contact with some soft substance beyond. The case was con- sidered to be one of compound fracture of the squamous bone, with separation of a fragment and exposure of the brain. A bystander, however, noticed that the bone removed was dry and white, and a more complete examination of the wound revealed the fact that the skull was uninjured, that the supposed hole in the skull was merely a laceration of the temporal fascia, that the soft matter beyond was muscle and not brain, and that the fragment removed was simply a piece of bone which, lying on the ground, had been driven into the soft parts when the woman fell. Abscesses in the temporal fossa are prevented by the fascia from opening anywhere above the zygoma, and are encouraged rather to spread into the pterygoid and maxillary regions and into the neck. The pericranium in the temporal region is much more adherent to the bone than it is over the rest of the vault, and subpericranial extrava- sations of blood are therefore practically unknown in this part of the cranial wall. Trephining-. — This operation is frequently per- formed in the temporal region, its object being I] TREPHINING 9 to reach extravasations of blood from the middle meningeal artery. This artery crosses the an- terior inferior angle of the parietal bone at a point 1^ inches behind the external angular pro- cess of the frontal bone, and lj inches above the zygoma. In cutting down to expose this artery tne following structures are met with in order : (1) The skin; (2) branches of the superficial tem- E>R.cqMA SUP.TEM.LlrtE Lambda Squamous Suture] POST.DlV.OFrtlD.AlEfl.AR 1 asteriom Supra /IeatalTriaacle Lateral Sinus Imori Ext. Auditory -Meatus Occipital Ar.t .Coronal suture Pronto Malar Suture ArtT Div op Mid. Mem. Art. Mid Mem. Art. !ait. Max Art Imt. Juqular Veim Ext. Carotid Art. Fig. 2. -Points to trephine for middle meningeal artery and lateral sinus. poral vessels and nerves ; (3) the fascia continued down from the epicranial aponeurosis; (4) the temporal fascia ; (5) the temporal muscle ; (6) the deep temporal vessels; (7) the pericranium; (8) the anterior inferior angle of the parietal bone. Trephining for meningeal haemorrhage and cerebral abscess. — At the anterior inferior angle of the parietal bone the anterior division of the middle meningeal artery lies with its companion veins in a deep groove or even canal in the bone. 10 THE HEAD AND NECK [Chap. A fracture of the bone, which is comparatively thin in the region of the pterion, is apt to involve the artery, leading to a subdural haemorrhage, with consequent compression of the brain. The pterion lies lj inches behind and h an inch above the notch of the fronto-malar suture — a point which can be readily felt (Fig. 2). Similar mea- surements — namely, li inches behind and \ an inch above — taken from the centre of the external auditory meatus — the meatal point, give the posi- tion of the posterior inferior angle of the parietal bone (asterion), beneath which lies the highest point of the lateral sinus (Fig. 2). A trephine opening, } of an inch in diameter, made over the asterion, will expose the lateral sinus, and give access to the temporo-sphenoidal lobe above it and to the cerebellum below it. > The posterior division of the middle meningeal, in the majority of cases, will be exposed by trephining at a point 1 inch above the external auditory meatus. These measurements apply to the head of the average adult; allowance must be made for youth and for the size and shape of the head. In finding pterion, a line is drawn backwards parallel to the upper border of the zygoma; in finding as- terion^ a line^ is drawn backwards along the meato-inionic line (Fig. 2), which passes from the centre of the external meatus to the most promi- nent point of the external occipital protuberance — the inion. Intracranial abscess is often due to middle-ear disease, and is then very commonly found in the temporo-sphenoidal lobe or in the cerebellum. It is estimated to be three times more common in the cerebrum than in the cerebellum. The abscess of the temporo-sphenoidal lobe is usually found in that part of the lobe which lies over the tegmen tympani — a thin plate of bone which forms the roof of the tympanum and of the antrum of the mastoid. The level of the tegmen may be indicated thus (Fig. 3) : a point is taken above the meatus in line with the upper border of IJ TREPHINING 11 the zygoma; this suprameatal point is joined with the asterion, which lies, it will be remem- bered, lj inches behind and i an inch above the meatus ; the anterior half of the above line corre- sponds to the tegmen tympani. A trephine open- ing made 1 inch above the level of the tegmen is the most likely to give access to a temporo- sphenoidal abscess. In dealing with an abscess of the cerebellum the best spot to select is, in the adult, l\ inches behind the centre of the meatus and J of an inch below the meato-inionic line. In some cases it is impossible to say whether the abscess is situated in the temporo-sphenoidal lobe or cerebellum. In such cases Mr. Dean trephines at a point which lies lj inches behind and \ of an inch above the centre of the meatus. The lateral sinus is thus exposed with a part of the dura mater above the tentorium cerebelli, through which the temporo-sphenoidal lobe may be explored. By ex- tending the trephine opening \ an inch downwards the cerebellum may be examined. Trephining for cerebral tumour. — The position of the opening in the skull is obviously determined by the localizing symptoms. It is remarkable that little trouble from haemorrhage has attended these operations. In any case, after trephining, the portion or portions of bone removed may— if properly treated — be replaced in the opening, and will serve, especially in youthful subjects, to make good the gap left by the operation. The osteo- blasts in the fragments remain alive and retain the power of bone-formation. In trephining the skull, the comparative thick- ness of the cranial wall in various parts should be borne in mind, and the large arteries of the scalp should be avoided if possible. In order to # accommodate the instrument to the varying thickness of the skull, the pin of the trephine is not allowed to protrude more than Ath of an inch. 12 THE HEAD AND NECK [Chap. The zygoma may be broken by direct or in- direct violence. In the latter case the violence is such as tends to thrust the upper jaw or malar bone backwards. When due to direct violence, a fragment may be driven into the temporal muscle, and much pain caused in moving the jaw. In ordinary cases there is little or no displacement, since to both fragments the temporal fascia is attached above and the masseter below. The zy- goma serves as a most useful guide to the position Frontal Pole. Anterior flOR/1 fiSSUREorSVLVIUS! PtERION IslamdofReil^ FRONTO/lALAR Suture Temporal ' Pole- Upper Rolandic Point Fissure of Rolando Parietal Eminence Parieto Occipital Fissure- Lambda For Lateral Ventricle- Post. Morn DESC.AfORfl for Tenp.-Spnen. Abscess Cerebellum Asterion T>m panic Plate Suprameatal Triangle Meatus Suprameatal Point , Fig. 3. -Diagram to show the position of the lateral ven- tricles, island of Reil, and temporal pole. of deep parts. Its upper border, in its posterior three-fourths, corresponds to the floor of the mid- dle fossa of the skull, and marks the lower border of the temporal lobe of the brain which lies in that fossa (Fig. 3) ; the articular eminence, felt so plainly near its root, marks the point at which the middle meningeal artery perforates the base of the skull by the foramen spinosum (Fig. 2), and also the position of the Gasserian ganglion (Fig. 30, p. 125); the post-glenoid spine is directly over the carotid canal (S. Scott). I] ARTERIES AND VEINS OF THE SCALP 13 Vessels and nerves of the scalp.— The supraorbital artery and nerve pass vertically up- wards from the supraorbital notch, which is situ- ate at the junction of the middle with the inner third of the upper orbital margin. Nearer the middle line the frontal artery and supratrochlear nerve ascend. This artery gives life to the flap that in rhinoplasty is taken from the forehead to form a new nose. The temporal artery, with the auriculo-temporal nerve behind it, crosses the base of the zygoma just in front of the ear. The vessel divides into its two terminal branches (the anterior and posterior) 2 inches above the zygoma. The branches of this artery, especially the an- terior branch, are often very tortuous in the aged, and afford early evidence of arterial degeneration. Arteriotomy is sometimes practised on the an- terior branch of this vessel. The superficial tem- poral vessels are very liable to be the seat of cirsoid aneurysm, as, to a less extent, are the other scalp arteries. The posterior auricular artery and nerve run in the groove between the mastoid process and the ear, and the occipital artery and the great occipital nerve reach the scalp just internally to a point midway between the occi- pital protuberance and the mastoid process. Certain of the emissary veins are of import- ance in surgery. t These veins pass through aper- tures in the cranial wall, and establish communi- cations between the venous circulation (the sinuses) within the skull and the superficial veins external to it. The principal emissary veins are the following : 1. A vein passing through the mas- toid foramen and connecting the lateral sinus with the posterior auricular vein or with an occi- pital vein. This is the largest and most constant of the series. The existence of this mastoid vein serves to answer the question, Why is it a com- mon practice to apply leeches and blisters behind the ear in certain cerebral affections? 2. A vein connecting the superior longitudinal sinus with the veins of the scalp through the parietal foramen. 14 THE HEAD AND NECK [Chap. '3. A vein connecting the lateral sinus with the deep veins at the back of the neck through the posterior condylar foramen (inconstant). 4. Minute veins following the twelfth nerve through its foramen, and connecting the occipital sinus with the deep veins of the neck. 5. Minute veins passing through the foramen ovale, foramen of Vesalius, foramen lacerum medium, and carotid canal to connect the cavernous sinus with (respec- tively) the pterygoid venous plexus, the pharyn- geal plexus, and the internal jugular vein. Then, again, many minute veins connect the veins of the scalp with those of the diploe. Of the four diploic veins, two (the frontal and anterior temporal) enter into surface veins (the supra- orbital and deep temporal), and two (the pos- terior temporal and occipital) enter into the lateral sinus. Lastly, there is the well-known communication between the extra- and intracranial venous circu- lation effected by the commencement of the facial vein at the inner angle of the orbit. In this com- munication the angular and supraorbital veins unite with the superior ophthalmic vein, a tribu- tary of the cavernous sinus. The veins within the cavities of the nose and middle ear also communi- cate with those of the meninges. Through these various channels, and through many probably still less conspicuous, inflammatory processes can spread from the surface to the in- terior of the skull. Thus we find such affections as erysipelas of the scalp, diffuse suppuration of the scalp, necrosis of the cranial^ bones, and the like, leading by extension to mischief within the diploe, to thrombosis of the sinuses, and to inflammation of the meninges of the brain. If there were no emissary veins, injuries and diseases of the scalp and skull would lose half their seriousness. Mis- chief may even spread from within outwards along an emissary vein. Erichsen reports a case where the lateral sinus was exposed in a compound frac- ture. The aperture was plugged. Thrombosis and I] VENOUS TUMOURS OF THE SKULL 15 suppuration within the sinus followed, and some of the pus, escaping through the mastoid vein, led to an abscess in the neck. Fig. 4. — Nerve areas of the face and scalp. A, A, Distribution of the first division of the fifth cranial nerve : A', nasal branch ; A", supratrochlear ; A'", supraorbital. B, B, Distribution of the second division : B', infraorbital branch ; B", malar branch ; B'", temporal branch. C, c, Distribution of third division : c\ mental branch : c", buccal branch ; C"', auriculo-temporal. 1, Area of great occipital ; 2, of small occipital : 3, of great auricular ; 4, of superficial cervical ; 5 , of third occipital. Certain venous tumours are met with on the skull. They consist of collections of venous blood under the pericranium that communicate, through 16 THE HEAD AND NECK [Chap. I holes in the skull, with the superior longitudinal sinus. They are median, are reducible on pressure, and receive a faint pulsation from the brain. The holes are sometimes the result of accident, others depend upon bone disease or atrophy over a Pac- chionian body, and a few are due to a varicose emissary vein or to a congenital defect in the cranium, especially in the neighbourhood of the parietal foramina. The scalp nerves, especially such as are branches of the fifth pair, are often the seat of neuralgia (Fig. 4). To relieve one form of this affection, the supraorbital nerve has been divided (neurotomy), or paralysed by an injection of absolute alcohol at its point of exit from the orbit. Some forms of frontal headache depend upon neuralgia of this nerve. The inner branch of the nerve reaches the middle of the parietal bone; the outer branch, the lambdoid suture. The lymphatics from the occipital and posterior parietal regions of the scalp enter the occipi- tal and mastoid glands; those from the frontal and anterior parietal regions go to the parotid glands, while some of the vessels from the frontal region join the lymphatics of the face and end in the submaxillary glands (Fig. 44, p. 197). CHAPTER II THE BONY VAULT OF THE CRANIUM Position of the sutures. — The bregma, or point of junction of the coronal and sagittal sutures, is in a line drawn vertically upwards from a point just in front of the external auditory meatus, the head being in normal position (Fig. 2). The lambda, or point of junction of the lambdoid and sagittal sutures, lies in the middle line, about 2^ inches above the occipital protuberance (Fig. 2). The lambdoid suture is fairly represented by the upper two-thirds of a line drawn from the lambda to the apex of the mastoid process on either side. The coronal suture lies along a line drawn from the bregma to the middle of the zygomatic arch. On this line, at a spot about li inches behind and 4 an inch above the fronto-malar junction, is the pterion, the region where four bones meet, viz. the squamous bone, the great wing of the sphenoid, the frontal and parietal bones (Fig. 2). The summit of the squamous suture is If inches above the zygoma. In the normal subject all traces of the fon- tanelles and other unossified parts of the skull disappear before the age of two years (Fig. 6). The anterior fontanelle is the last to close, while the posterior is already filled at the time of birth. It is through or about the anterior fontanelle that the ventricles are usually as- pirated in cases of hydrocephalus. The needle is either entered at the sides of the fontanelle at a sufficient distance from the middle line to 17 18 THE HEAD AND NECK [Chap. avoid the longitudinal sinus, or is introduced through the coronal suture at some spot other than its middle point. It may be noted that in severe hydrocephalus the coronal and other sutures of the vault are widely opened. The condition known as eranio-tafoes, a con- dition assigned by some to rickets and by others to inherited syphilis, is usually met with in the verti- cal part of the occipital bone, and in the adjacent parts of the parietal bones, but especially in the posterior inferior angles of these bones. In this condition the bone is greatly thinned in spots, and its tissue so reduced that the affected district feels to the finger as if occupied by parchment, or, as some suggest, by cartridge paper. The thinning is mainly at the expense of the inner table and diploe. The pits are situated over the impressions of early formed convolutions. It is, on the other hand, about the site of the anterior fontanelle that cer- tain osseous deposits are met with on the surface of the skull in some cases of hereditary syphilis (Parrot). These deposits appear as rounded ele- vations of porous bone situated upon the frontal and parietal bones, where they meet in the middle line. ^ The bosses are separated by a crucial de- pression represented by the frontal and sagittal sutures on the one hand and the coronal suture on the other. They have been termed " natiform " elevations by M. Parrot from their supposed resem- blance, when viewed collectively, to the nates. To the English mind they would rather suggest the outlines of a "hot-cross bun." It is necessary to refer to the development of the skull in order to render intelligible certain conditions (for the most part those of congenital malformation) that are not infrequently met with. Speaking generally, it may be said that the base of the skull is developed in cartilage, and the vault in membrane. The parts actually formed in mem- brane are represented in the completed skull by the frontal and parietal bones, the squamo-zygo- matic part of the temporal bone, and the greater II] MENINGOCELE 19 part of the expanded portion of the occipital bone. The distinction between these two parts of the skull is often rendered very marked by disease. Thus there are, in the museum of the Koyal College of Surgeons, the skulls of some young lions that were born in a menagerie, and that, in consequence of malnutrition, developed certain changes in their bones. A great part of each of these skulls shows considerable thickening, the bone being con- verted into a porous structure ; and it is remark- able to note that these changes are limited to such parts of the skull as are formed in membrane, the base remaining free. In hydrocephaly and in the condition known as achondroplasia, it is only the bones formed in membrane which are unduly ex- panded. Among the more common of the gross malforma- tions of the skull also is one that shows entire absence of all that part pi the cranium that is formed in membrane, while the base, or cartila- ginous part, is more or less perfectly developed — the condition of anencephaly. Meningocele is the name given to a con- genital tumour that consists of a protrusion of a part of the cerebral mem- branes through a gap in an imperfectly developed skull. When the # protrusion contains brain, it is called an encepha- locele, and when that pro- truded brain ^ is distended by an accumulation of fluid with- in the ventricles, it is called hydrencephalocele. These pro- trusions are most often met with in the occipital bone, and next in frequency in the fronto-nasal suture, while in rarer cases they have been met with in the lambdoid, sagittal, and other sutures, and have projected through normal and abnormal fissures at the Fig. 5. — The occi- pital bone at birth. 20 THE HEAT) AND NECK [Chap. base of the skull into the orbit, nose, and mouth. Their frequency in the occipital bone may be in some degree explained by a refer- ence to the development of that part. This bone at birth consists of four separate parts (Fig. 5), a basilar, two condylar, and a tabular or expanded part. In the tabular part, about the seventh week of foetal life four nuclei appear, an upper and a lower pair. These nuclei are to some extent separated by fissures running inwards from the four angles of the bone to meet T^ietopic Suture ..Frontal Eminence _.BREqNATIC fONTANELLE -.Coronal suture ..Saqittal Suture Parietal Eminence Sacittal Tontanelle UrtBDOIDALrOMTA/tELLE Inter Parietal Supra Occipital Fig. 6. — Skull of newly born child, from above. at the occipital protuberance. The gap running up in the median line from the inferior angle at the foramen magnum to the occipital protuberance is especially distinct (the temporary occipital fontanelle of Sutton). It exists from the beginning of the third to the end of the fourth month of intra-uterine life. Meningoceles of the occiput are always in the middle line, and the protrusion probably occurs through this gap. The gap associ- ated with meningocele may extend through the whole vertical length of the occipital bone, and very commonly opens up the foramen magnum. The lateral or transverse fissures divide the bone Hj FARIETAL FISSURES 21 into two parts. The upper part is developed from membrane, the lower part from cartilage. The lateral fissures may persist, and may simulate frac- tures, for which they have, indeed, been mistaken ; or they may be so complete as entirely to separate the highest part of the occipital bone from the remainder. The bone so separated is the 05 epactal of the French, the interparietal bone of some animals (Fig. 6). Parietal fissures. — In the developing parie- tal bone, fibres concerned in ossification radiate towards the periphery from two nuclei about the centre of the bone. An interfibrillar space, larger than the rest, is seen about the fifth month to separate the loose osseous fibres which abut on the posterior part of the sagittal border from the stronger fibres which form the rest of this border (Pozzi). This is the parietal fissure (Fig. 6). It usually closes and leaves no trace, but it may per- sist in part as a suture-like fissure, and be mistaken for a fracture. If the fissure persists equally on the two sides an elongated lozenge-shaped gap is left, the sagittal fontanelle (Fig. 6). It is situate about an inch in front of the lambda, and occurs in over 4 per cent, of newly born children (Lea). The parietal foramina are remains of this interval. Wormian bones. — These irregular bones may be mistaken for fragments produced by frac- ture. They are most usually met with in the lamb- doid suture. One Wormian bone deserves special notice, as it may be met with in trephining over the middle meningeal artery. It exists between the anterior inferior angle of the parietal bone and the great wing of the sphenoid. It is scale-like, and gives the impression that the tip of the great wing has been separated. It is known as the epipteric bone. Necrosis is fairly common on the vault of the skull, and most often attacks the frontal and parietal bones, while, for reasons that are not very obvious, it is rare in the occi- pital bone. The external table is frequently 22 THE HEAD AND NECK [Chap. necrosed alone, it being more exposed to injury and less amply supplied with blood than is the internal table. From the converse of these reasons it happens that necrosis of the internal table alone is but rarely met with. Necrosis in- volving the entire thickness of the bone may prove very extensive, and in a case reported by Saviard, practically the whole of the cranial vault necrosed and came away,. The patient was a woman, and the primary cause of the mischief was a fall upon the head when drunk. Necrosis of the skull, as well as caries of the part, is attended by certain special dangers that de- pend upon the anatomical relations of the cranial bones. Thus, when the whole thickness of the skull is involved by disease, or when the inner table is especially attacked, a collection of pus may form between the dura mater and the affected bone, and may produce compression of the brain. When the diploic tissue is implicated, the veins of that part may become thrombosed, or may be the seat of a suppurative phlebitis. The mischief thus^ com- menced may spread, the great intracranial sinuses may be closed by thrombus, or septic matter may be conveyed into the general circulation and lead to the development of pyaemia. Mere local extension may also cause meningitis. In cases of necrosis of the external table the growth of granulation tissue from the exposed and vascu- lar diploe ]Dlays a very important part in aiding the exfoliation of the lamella of dead bone. Fractures of the skull. — It is not easy ac- tually to fracture the skull of a young infant.^ The skull as a whole at this age is imperfectly ossified, the sutures are wide, and between the bones there is much cartilage and membrane. Moreover, the bones themselves in early life are elastic, and com- paratively soft and yielding. If a blow be inflicted upon the vault in a young child the most probable effect, so far as the bone itself is concerned, is an indenting or bulging-in of that bone unassqeiated with a fracture in the ordinary sense. In this par- II] FRACTURES OF THE SKULL 23 ticular relation the skull of an infant is to that of an old man as a cranium of thin tin would be to a cranium of strong earthenware. The yielding char- acter of the young child's skull is well illustrated by the gross deformity of the head that certain Indian tribes produce in their offspring by apply- ing tight bandages to the part in infancy. In the Royal College of Surgeons museum are many skulls of " flat-headed " Indians, that show to what an extreme this artificial deformity may be carried. Gueniot also asserts that much deformity of the head may be produced in infants by the practice of allowing them always to lie upon one side of the body. Here the deforming agent is simply the weight of the brain. Even in adults the skull is much less brittle than is commonly supposed, and notions as to the breaking ability of the cranial bones derived from the study of the dried specimens are apt to be erroneous. During life a sharp knife properly directed may be driven through the cranial vault so as to cause only a simple perforating wound with- out splintering, and without fracture of the bone beyond the puncture. Such a wound may be as cleanly cut as a wound through thick leather, and a specimen in the London Hospital museum serves well to illustrate this. A case reported in the Lancet for 1881 affords a strange instance of a knife penetrating the skull without apparently splinter- ing the bone. A man wishing to commit suicide placed the point of a dagger against the skull in the upper frontal region, and then drove it well into the brain by a blow from a mallet. He ex- pected to fall dead, and was disappointed to find that no phenomena of interest developed. He then drove the dagger farther in by some dozen blows with the mallet, until the blade, which was four inches long, was brought to a standstill. The dagger was removed with great difficulty, the patient never lost consciousness, and recovered without a symptom. The following anatomical conditions tend to 24 THE HEAD AND NECK [Chap minimize the effects of violence as applied to the skull : the density of the scalp and its great mobility ; the dome-like arrangement of the vault ; the number of the bones that compose the head, and the tendency of the violence to be broken up amongst the many segments ; the sutures which interrupt the continuity of any given force, and the sutural membrane, which acts as a kind of linear buffer ; the mobility of the head upon the spine ; and the elasticity of the cranial bones themselves. The skull is further strengthened by the pre- sence of six buttresses or pillars at the junction of the vault and base. Two of these are lateral, the orbito-sphenoid anteriorly and the petro-mastoid posteriorly, while the fronto-nasal and occipital strengthen the anterior and posterior ends of the skull. In children the membranous layer between the sutures is of considerable thickness, but as age advances this membrane disappears and the bones tend to fuse together (synostosis). The sutures begin to be obliterated about the age of 40, the change commencing on the inner aspect of the suture, and appearing first in the sagittal suture, then in the coronal and lambdoid, and last in the squamous. As age advances, moreover, the skull bones become thicker owing to a deposit over the inner table to replace the diminishing brain, and lose much of their elasticity. They are, there- fore, more readily fractured in the aged than in the young. As a rule, in fracture, the entire thickness of the bone is involved ; but the external table alone may be broken, and may even be alone depressed, being driven into the diploe, or, in the case of the lower frontal region, into the frontal sinus. The internal table may be broken without a corresponding frac- ture in the outer plate ; and in nearly all" cases of complete fracture, especially in such as are at- tended with depression, the internal table shows more extensive splintering than does the external. There are many reasons for this. The internal II] FRACTDKES OF THE SKULL 25 plate is not only thinner than the external, but is so much more brittle as to receive the name of the "vitreous table." A force applied to the external table may be extremely limited, and produce, as in a sabre cut, but a limited lesion. As the force, C however, travels through the diploe it becomes broken up, and reaches the inner plate as a much more diffused form of violence. This is especially the case when parts of the outer table are driven in. Then, again, the internal plate is a part of a smaller curve than is the external plate ; and, lastly, Agnew assigns a reason for the greater vul- C 3J Fig. 8. nerability of the inner plate that has reference to the general yielding of the bone. In Fig. 7, ab represents a section of a part of the vault through both tables, and c D and E f two vertical and paral- lel lines. Now, if force be applied to the vault be- tween these parallel lines, the ends of the arch, 26 THE HEAD AND NECK [Chap. A b, will tend to become separated, and the whole arch, yielding, will tend to assume the curve shown in Fig. 8. In such case, the lines CD and ef will converge above and diverge below (Fig. 8), so that the violence would tend to force the bone particles together at the outer table and asunder at the inner table. Fractures of the vault are due to direct vio- lence. The construction of the skull is such that the fracturing force is resisted in many ways. (1) When a blow is received on the vertex in the parietal region, the force tends to drive the upper borders of the two parietal bones inwards. Such driving-in of these borders must be associated with a corresponding outward movement of the inferior borders. This latter movement is forcibly resisted by the squamous bone and the great wing of the sphenoid, which overlap the lower edge of the parietal bone. Moreover, the force transmitted to the squamous bone is passed on to the zygomatic arch, which takes its support from the superior maxillary and frontal bones. This arch then acts as a second resisting buttress, and this transmission of force from the vertex to the facial bones is said to be illustrated by the pain often felt in the face after blows upon the top of the head. (2) If the upper part of the frontal bone be struck, the force is at once transmitted to the parietal bones, be- cause the upper part of the frontal bone (owing to the manner in which its border is bevelled) actu- ally rests upon the two parietal bones ; so the same resistance is again called into action. If there be any tendency for the inferior parts of the bone to move outwards, as would certainly be the case while the mid-frontal suture existed, such movement would be resisted by the great wings of the sphenoid and by the anterior inferior angles of the parietal bones which embrace or overlap these parts of the frontal. Thus it will be seen that much depends upon the manner in which the corresponding edges of the frontal and parietal bones are # bevelled. (3) Blows upon the occiput are less distinctly pro- IIJ FRACTURES OF THE SKULL 27 vided for, and it must be owned that a by no means heavy fall is sufficient to break this bone. It must receive, however, much protection from its connections with the two parietal and tem- poral bones, and from its articulation with the elastic vertebral column. Fractures of the base of the skull may be due to (1) direct or (2) indirect violence, or, most commonly of all, to (3) extension of a fracture from the vault, (l) The base has been fractured by direct violence due to foreign bodies thrust through the nasal roof, through the orbital roof, and through the base as it presents in the pharynx. The posterior fossa can also be fractured by vio- lence applied to the nape of the neck. (2) Of frac- tures by indirect violence the following examples may be given : Blows applied to the lower part of the frontal bone have been associated with no lesion other than a fracture of the cribriform plate or of the orbital part of the frontal, these parts being much disposed to fracture on account of their extreme tenuity. In 86 cases of fracture of the base of the skull, the orbital roof was involved in 79, the optic foramina in 63, and the cribriform plates in nearly all (Raw- ling). ^ In falls upon the chin, the condyle of the lower jaw has been so violently driven against the glenoid cavity as to fracture the middle fossa of the skull.^ The force of a " knock-out " blow applied to the point of the chin produces concussion of the brain without fracture of the skull. When the body in falling has alighted upon the feet, knees, or but- tocks, the force has been transmitted along the vertebral column, and has led to fracture of the base in the occipital region. Such accidents are most apt to occur when the spine is kept rigid by muscular action, and the mechanism involved is precisely similar to that whereby the head of a broom is driven more firmly on to the broom-handle bv striking the extreme end of the stick ^ against the ground. The theory that the base is often broken by contre-coup is pretty generally abandoned, 28 THE HEAD AND NECK [Chap. though there are a few cases that appear to support the suggestion. Such a case was recorded by Sir J. Hutchinson, and in it a fracture of the occipital bone was associated with a like lesion in the cribri- form plate, the intervening part of the skull being uninjured. (3) Fractures of the vault, and especi- ally linear fractures due to such diffused violence as obtains in a fall upon the head, are very apt to spread to the base. In so spreading they reach the base by the shortest possible route, and without any regard to the sutures encountered or to the density of the bones involved. Thus, fractures of the frontal region of the vault spread to the an- terior fossa of the base, those of the parietal region to the middle fossa, and those of the occipital region to the posterior fossa. To this rule there are but few exceptions. To indicate more precisely the exact bones involved in these three districts, P. Hewett has divided the skull into three zones. The anterior zone includes the frontal, the upper part of the ethmoid, and the f ronto-sphenoid ; the middle, the parietals, the squamous and anterior part of the petrous of the temporals, and the greater part of the basi-sphenoid ; and the pos- terior, the occipital, the mastoid, the posterior part of the petrous bone, with a small part of the body of the sphenoid. In all fractures of the base there is usually a discharge of blood and of cerebro-spinal. fluid ex- ternally. (1) In fractures of the anterior fossa the blood usually escapes from the nose, and is derived from the meningeal and ethmoidal vessels, or in greater degree probably from the torn mucous lin- ing of the nasal roof. To allow of the escape of cerebro-spinal fluid from the nose, there must be, in addition to the fracture in the nasal roof, a lacer- ation of the mucous membrane below that fracture, and of the sheaths of the olfactory nerves which are derived from the dura mater and arachnoid. A profuse discharge of cerebro-spinal fluid may take place through the nasal mucous membrane inde- pendently of inj ury. The discharge probably occurs II j FKACTUBES OF THE SKULL 29 along the sheaths of the olfactory nerves, and is caused by a lessened absorption or increased secretion of cerebro-spinal fluid. In many cases of fracture in this part the blood finds its way into the orbit, and appears beneath the conjunctiva. (2) When the middle fossa is involved, the blood escapes from the external auditory meatus, through a rupture in the tympanic membrane, and is de- rived from the vessels of the tympanum and its membrane, or from an intracranial extravasation, and in some cases from a rupture of the cavernous or petrosal sinuses. The blood may follow the Eustachian tube, and may escape from the nose or mouth, or be swallowed and subsequently vomited. To allow of the escape of cerebro-spinal fluid by the ear ("the serous discharge "), (a) the fracture must have passed across the internal auditory meatus ; (b) the tubular prolongation of the membranes in that meatus must have been torn ; (c) there must be a communication between the internal ear and the tympanum ; and (d) the membrana tympani must have been lacerated. (3) In fractures of the posterior fossa an extravasation of blood may ap- pear about the mastoid process or at the nape of the neck, or may even extend into the cervical region. It may be added that in compound fractures of the vault associated with tearing of the dura mater and arachnoid, an escape of cerebro-spinal fluid has in a few rare instances been noted. After simple fracture of the vault in children a swelling may form at the injured part which fluctuates, be- comes tenser when the patient cries, and may pos- sibly pulsate synchronously with the brain. Such swellings are due to a collection of cerebro-spinal fluid beneath the scalp, and indicate a coincident rupture of the brain membranes. Separation of sutures. — This condition, as the result of injury, is practically restricted to the young skull. In later life, force applied at the site of an obliterated suture may cause a fracture, which accurately follows the old suture line. Separ- ation of the sutures, independent of fracture, is 30 THE HEAD AND NECK [Chap. II very rare in the adult skull. In the few instances of such a condition the temporal bone has usually been the one displaced and the separation noted at the squamous suture. When associated with fracture, the coronal and sagittal sutures are those most frequently separated, and the next in fre- quency is the' lamb do id. The thickness of the skull cap varies greatly, not only in different parts of the same skull, but also in corresponding parts in different individuals t The average thickness is J of an inch. It varies with age; at birth the parietal is less than A of an inch ; at three years diploe appear, marking off the inner from the outer table of the skull ; in old people the parietal bone may be J of an inch or J of an inch in thickness. The thickest parts are at the occipital protuberance (where the section may measure J an inch), the mastoid process, and the lower part of the frontal bone. The bone over the inferior occipital fossae and orbit is very thin, while it is thinnest over the squamous bone. Here the bone may be no thicker in parts than a visiting card. The skull is also thinned over the sinuses and grooves for the meningeal vessels. It is especially thin over the anterior in- ferior angle of the parietal bone. It is important to remember in trephining that the inner table is not always parallel with the outer. Craniectomy. — This operation is carried out in cases of microcephaly in infants and chil- dren. It consists in the removal of a strip of bone from the vertex of the skull so as to give to the brain, as an American author expresses it, " more elbow room." The operation presumes that the arrest of growth in the brain is due to a retarded growth of the skull, but all the evidence at our dis- posal points to the^ arrest in the development of the brain as the primary lesion; the condition of the skull being a consequence. In hydrocephalv the skull is seen to respond readily to the quick expansion of the brain ; if the growth of the brain is arrested, the skull remains small. CHAPTER III THE CRANIAL CONTENTS Membranes of the brain.— The dura mater, from its toughness, forms an excellent protec- tion to the brain. It is very intimately adherent to the bone over the whole of the base of the skull, and consequently in this situation extrava- sations between the membrane and the bone are scarcely possible. Over the vault its attachments are comparatively loose, although it is more closely adherent along the lines of the sutures. This lax attachment allows large hemorrhagic and puru- lent extravasations to collect between the dura mater and the bone. Such extravasations usually lead to compression of the brain, and it may be noted that in the great majority of all cases of compression the compressing force is outside the dura mater. Thus, in uncomplicated cases when symptoms of compression come on at the time of an accident, the cause is probably depressed bone ; when they appear after a short interval, the cause is probably extravasated blood between the mem- brane and the bone; and when a long interval (days or weeks) has elapsed after the accident, the cause is probably a collection of pus in the same situation. Sir C. Bell pointed out that the dura mater of the vault may be separated from the bone by the vibration produced by a blow. "Strike the skull of a subject with a heavy mallet ; on dissecting you find the dura mater to be shaken from the skull at 31 32 THE HEAD AND NECK [Chap. the point struck. Repeat the experiment on an- other subject, and inject the head minutely with size injection, and you Trill find a clot of injection lying betwixt the skull and dura mater at the part struck, and having an exact resemblance to the coagulum found after violent blows on the head." Tillaux has demonstrated that the adhesions be- tween the dura mater and the bone are particularly weak in the temporal fossae, the most usual site of meningeal haemorrhage. When blood is poured out between the dura mater and the bone in cases of fracture, the vessel that as a rule gives way is the middle meningeal artery* In thirty-one cases of such haemorrhage, this vessel was the source of the bleeding in twenty-seven instances (P. Hewett). The vessel, having passed through the foramen spinosum, divides into two branches ; the anterior, the larger, runs upwards across the anterior in- ferior angle of the parietal bone and ascends the vault some distance behind the coronal suture ; the posterior runs backwards, with a horizontal sweep across the squamous bone, and takes the course of the second temporal convolution. (See Figs. 2, 3.) Mr. Jacobson has shown that the branches of the artery are more frequently ruptured than the trunk. The vessel is very frequently torn as it crosses the anterior angle of the parietal bone. There are many reasons for this : the bone where grooved by the artery is very thin ; the artery is often so embedded in the bone that fracture with- out laceration of the vessel would hardly be pos- sible ; and lastly, the particular region of the artery is a part of the skull peculiarly liable to be fractured. Mr. Jacobson shows that the artery may be ruptured by a force that does not fracture the skull, but merely leads to detachment of the dura mater. Failing this vessel, the most frequent source of extrameningeal haemorrhage is the lateral sinus, for reasons that will be obvious. Venous sinuses. — The flaccid-walled cerebral Ill] VENOUS SINUSES 33 veins, which are compressed with each pulsa- tion of the brain, empty into the venous sinuses, rigid-walled cavities formed between the outer or periosteal and inner or supporting layers of the dura mater. At the points where the superior cerebral veins enter the superior longitudinal sinus, and where the temporo-sphenoidal and occipital veins join the lateral sinus, the arach- noid, elsewhere free from dura mater, is firmly adherent to it. From a surgical point of view the lateral is the more important sinus ; and as it turns downwards beneath the mastoid process it comes into close relationship with the antrum and cells of the mastoid, from which a septic con- dition may spread to the sinus, setting up throm- bosis (see Fig. 22, p. 90). The lateral sinus is marked out by taking the following three points (see Fig. 2, p. 9, and Fig. 3, p. 12) : (1) The inion, (2) the asterion, (3) a point i an inch behind the lower border of the meatus. When these three points are joined, the lateral sinus is seen to be made up of two parts — a horizontal, which gradu- ally ascends as it passes from the inion to the asterion; and a vertical, which rapidly descends from the asterion to the postmeatal point. The sinus is 10 mm. wide. The lateral sinus escapes from the skull to form the internal jugular vein in line with the anterior border of the mastoid process, but situated deeply beneath the parotid gland (Fig:. 2, p. 9). A line drawn over the vault of the skull from nasion to inion marks the line of the superior longitudinal sinus ; beneath the posterior third of the sagittal suture it may not keep exactly to the middle line, and in this part of its course it frequently shows lateral extensions or diverti- cula known as parasinoids. In the majority of cases the superior longitudinal ends in the right lateral sinus, which is hence commonly larger than the left. The cavernous sinus, enclosing the internal carotid artery and sixth cranial nerve, with the third, fourth, and greater part of the fifth embedded in its wall, is situated over the c 34 THE HEAD AND NECK [Chap. sphenoidal air sinus, from which septic conditions may extend to it, giving rise to thrombosis. In such cases the eyes become prominent owing to the distension of the ophthalmic veins, for the venous stream from the orbit flows through the cavernous sinus to reach the lateral sinus and jugular vein by means of the superior and inferior petrosal sinuses. Tumours of the pituitary necessarily compress the cavernous sinus. The relations between the in- ternal carotid artery and cavernous sinus are so intimate that an arterio-venous aneurysm has followed injury involving these # parts. It will be seen also with what ease this sinus could become thrombosed in cases of inflammation within the orbit by^ the extension of the mischief along its great tributaries, the two ophthalmic veins. Between the dura mater and the arachnoid is the^ subdural space, which, like the pleural cavity, is merely a potential space, for in health the arachnoid is closely applied to the smooth inner surface of the dura mater. A space is formed only when fluid, blood, or pus is collected between the two membranes (Fig. 1, p. 2). The subdural space contains a small amount of fluid, and acts, like the pleural and peritoneal sacs, in prevent- ing the effects of friction during the pulsatory movements of the brain. A knowledge of the subarachnoid space is steadily becoming of greater surgical importance. The space which surrounds the spinal cord is in direct continuity with the subarachnoid spaces of the brain, and hence, when this space is tapped in the lumbar part of the spinal canal (Fig. 135, p. 641), the fluid situated in the subarachnoid spaces of the brain is also drained off (Fig. 9). In meningitis the cerebro-spinal fluid becomes turgid; the subarachnoid space, or parts of it, may contain pus. In the spinal column the arachnoid is widely separated from the nia mater, hence the subarach- noid space is extensive. As the space passes into the skull it forms an expansion between the cere- bellum and roof of the fourth ventricle named the Ill] SUBARACHNOID SPACE 35 cisterna magna (Fig. 9); an opening in the roof of the fourth ventricle (the foramen of Magendie) allows the cerebro-spinal fluid in the ventricles of the brain to join that in the cisterna magna (Fig. 9). On the base of the skull, in front of the medulla and pons, the spinal subarachnoid space expands into the cisterna pontis, which in turn becomes continuous with a large space situated on the base of the brain between the temporal lobes and under eoce of arachnoid Supra-Callosal Space ERAlVENTRICIE- CE/1U CALL050 ttARClNAL SPACE Supra Callosai Space splenium Velum InterpositunI Pt/IEAL CLA»D Tentorium Cerebeui Aqueduct op Sylviu: Fourth Ventricle Foramen ©p/^acendie. Cisterna macna Foramen op MONRO Third "entricle ub Callosu Space Cisterna BA5ALI5 Optic /terve Pituitary Body ^Internal ;arotio art- Fig. 9. — Diagram of the cranial spaces containing cerebro-spinal fluid. the interpeduncular space — the cisterna basalis (Fig. # 9). In this cistern are situated the circle of Willis, the third, fourth, and root of the fifth nerves, the optic chiasma and tracts and infundi- bulum of the pituitary body. In basal meningitis it may become distended with pus. The inflam- matory adhesions which occur in the inferior medullary velum may lead to a condition of hydrocephaly by closing up the openings in that membrane. Over the convolutions of the brain the arachnoid is bound by the pia mater, which 36 THE HEAD AND NECK [Chap. here serves as a loose subarachnoid tissue. Every- where extensions of the basilar cistern pass out with the arteries derived from the circle of Willis into the pia mater in the sulci of the brain. While the interpeduncular part of the base of the brain, pons and medulla rest on these basal cisterns, the temporal and frontal lobes lie directly on the base of the skull ; the occipital lobe rests on the ten- torium cerebelli. The three poles of the brain — the frontal, occipital, and temporal — are in direct contact with the meninges and skull, and are therefore the parts # of the brain that are most liable to laceration in cases of injury to the head. The cerebro-spinal fluid prevents the ill effects that irregularities in the blood circulation might have upon the brain, situate as it is within an un- yielding cavity. If the great nerve centres near the lateral ventricles are swollen by congestion, they are not met by an unyielding wall, but merely dis- place some of the cerebro-spinal fluid through the foramen of Magendie, until such time as their circulation is normal again. When the healthy brain is exposed by a trephine opening it is seen to pulsate with each beat of the heart; if it does not pulsate, this shows that the pressure within the skull is higher than the arterial pressure (100-130 mm. Hg) ; normally, as Hill has shown, the intracranial pressure is that of the blood- pressure in the veins (10-15 mm. Hg). With each pulsation of the heart about 5 c.c. of arterial blood is thrown into the skull, causing the ejection of a similar amount of venous blood by the jugular vein. Fluid may pass from the lateral to the third ventricle by the foramen of Monro : from the third to the fourth ventricle by the aqueduct of Sylvius ; and from the fourth ventricle > to the cisterna magna by the foramen of Magendie (Fig. 9). Many still share the opinion of Hilton that blockage of the aqueduct, or closure of the foramen of Magendie, or of the other two openings at the lateral angles of the fourth ventricle (the fora- Ill] CEREBKO-SPINAL FLUID 37 mina of Key and Retzius) may prevent the exit of cerebro-spinal fluid from the ventricles and thus produce the condition of hydrocephaly. The fluid also drains into the veins of Galen, hence pressure on these may bring about a like result. It has been proposed to relieve the pressure within the lateral ventricles in cases of hydrocephaly by draining the cerebro-spinal fluid into the subdural space by means of a seton. It is absorbed under any pressure above that within the cerebral veins (Hill). If the brain, too, becomes enlarged by congestion, it is not met by unyielding bone, but rather by an ad- justable water-bed, and during its period of en- largement it merely displaces into the spinal part of the subarachnoid space some of the fluid that surrounds it. This mutual effect is well illustrated in a case reported by Hilton of a man with a frac- ture of the base, from whose ear cerebro-spinal fluid was escaping. The discharge of this fluid was at once greatly increased by expiratory efforts when the nose and mouth were held closed and the veins compressed in the neck. » Cerebro-spinal fluid. — The total amount of fluid in the cerebro-spinal system of an adult is estimated at 100-130 c.c. (about 4 oz.). It is secreted by the choroid plexuses (1) in the lateral ventricles, (2) in the roof of the third ventricle, and (3) in the roof of the fourth ventricle, the ependymal epithelium covering these plexuses being regarded as the actual structure carrying out the secretion. The fluid is absorbed by (1) the lymphatic spaces surrounding the nerve roots, (2) by passage into veins and venous spaces, and (3) the Pacchionian bodies may also serve as a means whereby it enters the venous system. Methylene blue, when injected into the spinal subarachnoid space, quickly appears in the ven- tricles of the brain, from which we see that diffusion takes place rapidly. Pituitary body,_In recent years the pitui- tary body, enclosed within a special compartment of the dura mater, and placed on the upper 38 THE HEAD AND NECK LChap. surface of the basi-sphenoid, has assumed an increased surgical importance. In Fig. 10 its form and relationships are shown as seen in a young child. Its stalk descends from the floor of the third ventricle, and ends in the posterior or neural lobe. The anterior or glandular lobe is applied to the neural lobe and embraces it on each side. The glandular lobe, which arises as 3rd Ventricle Optic Chiasma Arach. Dura Mater Infundibulum Presphen. Perineural Lobe Preneural Lobe Dorsum Sell-« Basilar Art. Track of Development Septum Nasi fharyng. Pituitary Fig. 10. — Section of the pituitary body, third ventricle, basi-sphenoid, and naso-pharynx of a child aged 15 months. The remnant of the stalk of the pituitary out- growth is represented in the roof of the naso-pharynx. an outgrowth from the stomodseum or mouth- depression of the embryo, is divided into two parts — a perineural, which is closely applied to the neural lobe, and an anterior or preneural part. The perineural and preneural parts are separated by a central cavity, which is obliterated as adult life is reached (Fig 10). The preneural glandular part may become hypertrophied and form a glandular tumour, and in many of these Ill] PITUITARY BODY 39 cases various parts of the body — especially the face, hands and feet^begin to grow, and attain a large size, giving rise to the condition known as acromegaly. If the hypertrophy occurs in youth, then all the bones of the skeleton grow rapidly, and the condition of giantism is^ pro- duced. The preneural glandular part of the pituitary — evidently by means of an internal se- cretion — regulates the growth of the various parts of the body, and, if secretion is in excess, leads to overgrowth. Numerous cases have been relieved by operation, part of the glandular lobe being scraped away. In the adult, access to the pituitary is obtained through the sphenoidal sinus, on the roof of which this body is situated. The sinus is reached by reflecting the cartilaginous part of the nose and following the septum nasi backwards until the sphenoidal sinus is reached. Pituitary tumours, as they expand, compress the cavernous sinuses, and, from their close relationship to the optic nerves, lead usually to a partial optic atrophy and blindness. ^ The tumour may depress the roof of the sphenoidal sinus. In Fig. 10 a remnant of the stalk of the developing pituitary is shown in the roof of the naso-pharynx. Erdlieim found that this remnant of the foetal pituitary (the naso-pharyngeal pituitary) occurred in every one of the bodies that he examined — over fifty in number. The blood supply of the pituitary is from numerous vessels which arise from the circle of Willis and descend in the stalk of the pituitary. The pituitary is contained within a compartment of the dura mater, the roof of which is perforated by the stalk of the body. Surface relationships of the brain (see Figs. 11 and 12). — The longitudinal fissure of the brain is indicated by a line drawn along the vertex from the glabella to the external occipital protu- berance. It is narrow in front, but as it contains the longitudinal sinus, which rapidly enlarges as it passes backwards, it becomes of considerable breadth behind, and as a rule lies somewhat 40 THE HEAD AND NECK [Chap towards the right of the median line, owing to the predominance of the left cerebral hemisphere. FISSUREof ROLANDO. PARIETAL EMINEI BREGMA Fig. 11. — Showing the relation of the brain and sensori- motor areas of the cortex to the skull- (Modified from Quain. ) The sensori-motor areas are shaded— the leg and trunk areas with vertical lines ; the arm and hand areas with lines slanting for- wards ; the face and mouth areas with lines slanting back- wards ; the tongue, pharynx, and larynx areas are stippled. The ascending frontal convolution, containing the areas which are strictly motor in function, is indicated by red lines. The motor centre for speech on Broca's convolution is shaded with horizontal lines. The " word-hearing " centre is indicated on the superior temporal convolution, and the " word-seeing " centre on the angular convolution. The area shaded with horizontal lines on the posterior parts of the middle and inferior frontal convolutions is the centre for combined movements of the head and eyes. Between the external occipital protuberance and the ear, the lateral sinus bounds the lower level of Ill] FISSURE OF ROLANDO 41 the cerebrum and the upper of the cerebellum (Figs. 3 and 11). In front of the ear the upper border of the zygoma in its posterior three-fourths marks the lower border of the temporal lobe. The pole of the temporal lobe is } of an inch behind the outer margin of the orbit (see Fig. 3). The lower limit of the brain on the forehead may be indicated approximately by drawing a line from the glabella to the Sylvian point, \ an inch above the upper margin of the orbit. The olfactory bulbs he at the level of the nasion (Fig. 3). The cerebellum is best explored at a point lj inches behind and | an inch below the level of the external auditory meatus (see Fig. 3, p. 12). ^ It is deeply placed, being covered by the insertions of the occipital muscles. Of the many methods which have been sug- gested for marking out the fissure of Rolando, the most simple and accurate is the following : A point over the sagittal suture is taken ^ midway between the glabella and external occipital pro- tuberance. Half an inch behind this mid-point the upper end of the fissure terminates (Fig. 12). A line 3i inches long drawn downwards and forwards from this point, at an angle of 67° to the .line of the sagittal suture, will indicate the position of the fissure of^ Rolando in the adult. In the child the fissure is shorter and the con- tained angle is 5° smaller. The angle is easily obtained by folding twice the corner of a square piece of paper and removing a fourth of the right angle. This line may not lie exactly over the fissure, for it varies somewhat in position according to the shape of head. The sensori- motor areas of the brain are mostly represented in the ascending frontal and parietal convolu- tions which bound the fissure of Rolando. The average . width of each of these convolutions is f of an inch. The coronal suture is about 2 inches in front of the fissure of Rolando at its upper part and \\ inches at its lower. The fissure of Sylvius is indicated thus 42 THE HEAD AND NECK [Chap. (Fig. 12) : A point is taken lj inches behind and | an inch above the fronto-malar junction, which is indicated by a distinct notch. This point UPPER R0LA/1DIC POINT Fig. 12. — Showing the lines which indicate the position of the principal fissures of the brain. Reid's base line is drawn from the lower margin of the orbit back- wards through the meatal point. on the temple overlies the anterior inferior angle of the parietal bone — the pterion. The pterion marks the j unction of the three limbs of the fissure of Sylvius with its stem. A line drawn 1I1J FISSURE OF SYLVIUS 43 backwards and upwards from the pterion to a point | of an inch below the parietal eminence indicates the situation of the posterior horizontal limb or ramus (Fig. 12). If the parietal eminence be not well marked, then the fissure may be in- dicated by joining the fronto-malar notch with the pterion and prolonging the line thus formed straight backwards to the region of the parietal eminence, as shown in Fig. 3 (R. J. Berry). This ramus is bounded below by the superior temporal convolution, which contains in its middle third the " word-hearing " centre (Fig. 11). Above, it is bounded from before backwards by the basilar part of the inferior frontal convolution, the lower ends of the ascending frontal and parietal con- volutions, and the supramarginal gyrus. In the three parts first named are situated centres for movements of the tongue, larynx, pharynx and mouth. A penny piece placed directly behind the termination of the Sylvian line will cover the angular convolution in which the "word-seeing V centre is placed (Fig. 11). The parietal eminence covers the supramarginal convolution. The ascend- ing limb of the fissure of Sylvius is indicated by a line j of an inch long drawn upwards and slightly forwards from the pterion, while the short anterior horizontal limb is indicated by a line \ an inch long drawn forwards from the same point. Between the ascending and anterior limbs is situated the pars triangularis of the inferior frontal convolution in which the centre for " motor speech ,; is placed. Broca regarded the left inferior frontal > convolution (frequently called Broca's convolution) as specially connected with speech, but recently Pierre Marie has pub- lished accounts of a number of cases of disease of this part in which speech was unaffected. The stem of the Sylvian fissure is \ an inch long and runs downwards and forwards under the great wing of the sphenoid (Fig. 11). The temporal pole lies below it. The four angles of the parietal bone have 44 THE HEAD AND NECK [('hap. important relationships to the brain. The anterior inferior angle covers the posterior part of the in- ferior frontal convolution and the anterior hori- zontal and ascending limbs of the fissure of Syl- vius. The anterior branch of the middle meningeal artery ascends beneath it. The anterior superior angle at the bregma covers the terminal part of the superior frontal convolution and the centre for movements of the hip. The posterior superior angle at the lambda lies over the upper part of the occipital lobe and \ an inch behind the parieto-occipital fissure. The posterior inferior angle covers the convexity of the lateral sinus and marks the lower limit of the cerebrum. In its anterior half the posterior limb of the Sylvian fissure lies beneath the squamous suture, but be- hind it passes entirely beneath the parietal bone. It will be thus seen that the parietal bone covers the whole of the parietal lobe, the posterior parts of the frontal and temporo-sphenoidal lobes, and the upper margin of the occipital. The inferior temporal convolution passes backwards above the upper border of the zygoma and external auditory meatus and rests on the thin roof of the tympanum. Hence it is the most common site of abscess which may follow middle- ear disease. (Fig. 11.) The basal ganglia of the brain — the corpus striatum and optic thalamus — are capped on their outer aspect^ by the island of Reil. The island lies buried in the anterior three-fourths of . the fissure of Sylvius, and hence the surface markings for the fissure may be also used for the island and the basal ganglia ^ (see Fig. 3,^ p. 12). A half-circle, with a radius of ^ an inch, drawn in front of the pterion, will indicate the anterior limit of the basal ganglia, while their posterior limit lies some distance in front of the point at which the lateral ventricles may be tapped (see Fig. 3, p. 12). That point is found thus : a line 5 cm. (2 inches) in length is drawn verti- cally upwards from the external auditory meatus ; Ill] SENSORI-MOTOR AREAS 45 the point for tapping the lateral ventricle lies 2 cm. (J of an inch) behind the upper end of this line; a trocar thrust in there enters the lateral ventricle at the junction of the body with the descending and posterior horns. (Jenkins.) Sensori-motor areas of the brain. — A knowledge of the position of these areas is most important in enabling certain brain lesions to be localized and in guiding the surgeon in operations upon the cerebral cortex. Formerly these areas were believed to be situ- ated in the ascending frontal (precentral) and also ascending parietal (postcentral) convolution, but by stimulating more accurately the cortex of these convolutions in anthropoid apes, Sherrington and Griinbaum found that motor reactions were elicited only from the ascending frontal. The arrangement of the motor areas is shown in Fig. 13 : in the upper third of the ascending frontal, passing also some distance on to the mesial aspect of the brain, the movements of the lower extremity and trunk are represented; in the middle third, those of the arm; while in the lower third, those of the face, mouth, and larynx. Behind the fis- sure of Rolando, in the ascending parietal con- volution, are situated sensory areas corresponding to the motor areas in the ascending frontal con- volution. A tumour pressing on the surface of the brain first excites the cortex to action; hence one situated over a motor area excites the move* ments represented in that area, or one over a sen- sory area excites the sensations represented there. Stimulation of the cortex is soon followed by its destruction and loss of function; hence loss of movement or loss of sensation replaces the pre- liminary excitement. The symptoms produced by intracranial growths are apt not to be definitely localized, because even a small tumour may pro- duce widely distributed compression effects when it is situated within the rigid walls of the skull. Conjugate movements of the eyes are represented in the cortex at the posterior end of the mid- 46 THE HEAD AND NECK [Chap. frontal convolution (Fig. 13). There are also several primary sensory areas of cortex — areas connected with sight, hearing, and smell — which may be affected by intracranial lesions, and give signs which assist the surgeon to localize the seat of disease. The visual cortex is situated near the calcarine fissure and round the occipital pole; the "word-seeing" centre occupies the angular gyrus (Fig. 11) ; the auditory cortex lies in a deep Fig. 13. — Showing the localization of motor areas in the precentral or ascending frontal convolution, and the sensory areas in the postcentral or ascending parietal convolution. or buried part of the superior temporal convolu- tion, while the " word-hearing " centre is ascribed to the middle third of this convolution. The ol- factory cortex is placed in the uncus, which is situated to the inner side of the temporal lobe. Tumours in the neighbourhood of the uncus, besides producing disturbance of the olfactory sensations, frequently give rise to "dreamy states." Ill] THE BEAIN 47 Of the brain generally little has to be said. In a surgical sense, it presents itself simply as a large mass of soft tissue that may be damaged by shaking, as gelatin may be when shaken in a case. As it is of very yielding structure, and does not entirely fill the cranial cavity, it may,* as it were, be thrown about with the skull, and be damaged by collision with its walls. < In contusion or bruis- ing of the brain it is noticed that the lesion is very much more frequently situate on the under surface, both as regards the cerebrum and cere- bellum, than in any other part (see p. 36). To this statement, however, there is the striking exception that those parts of the base of the cerebrum that rest upon the large basal collection of the cerebro-spinal fluid are the least often con- tused. These parts include the medulla, the pons, and the interpeduncular space. The brain is very lavishly supplied with blood- vessels. The main arterial trunks (vertebral and internal carotid) are both rendered tortuous be- fore entering the skull, with the object probably of diminishing the effects of the heart's systole upon the brain. On entering they are almost immedi- ately blended into an anastomosing circle (circle of Willis)^ which has the effect of equalizing the cerebral circulation. Embolism of the middle cerebral artery leads to a wide-spread destruc- tion of the cerebral cortex. It supplies the third frontal, the upper and middle temporal, the angu- lar, supramarginal, and the lower two-thirds of the ascending frontal and parietal gyri. The only parts of the sensori-motor areas which escape de- struction in such a case are those for the lower limbs and trunk. The anterior cerebral artery supplies these centres, the mesial surface of the frontal and parietal lobes, and the adjacent part of the cortex on the outer aspect. The occipital lobe and temporo-sphenoidal convolutions are supplied by the posterior cerebral artery. Liga- ture of one common carotid may produce no effect upon the brain, although the mortality after this 48 THE HEAD AND NECK [Chap. operation is mainly due to cerebral complications. One carotid and the two vertebrals would appear to be able to bring enough blood to the brain, which blood will be as evenly distributed as hitherto by the circle of Willis. Both common carotids have been ligatured, or one carotid has been secured when its fellow of the opposite side has been occluded by disease, and no marked cere- bral disturbances have followed. In no case, how- ever, has the patient recovered when the interval between the closing of the two vessels was less than a few weeks. The vertebral arteries can carry a sufficient amount of blood to the brain if only the strain^ be thrown upon them gradu- ally, and the brain be allowed to accommodate itself slowly to the change. After ligaturing al] four arteries in the dog, the anastomosis between the spinal and cerebral arteries within the fora- men magnum was sufficient to maintain life (Hill). Plugging of any of the smaller cerebral arteries by emboli, as a rule, leads at^ once to a marked disastrous result. Such embolism is met with in surgery in connexion with aneurysm of the common carotid. In simply examining such aneurysms, a little piece of the clot contained in the sac has been detached, has been carried up into the brain, and has produced a plugging of one of the cerebral vessels. Thus, hemiplegia has followed upon the mere examination of a carotid aneurysm, as in a case recorded by Mr. Teale, of Leeds. Fergusson's treatment of aneurysm at the root of the neck, by displacing the clots by mani- pulation, has been abandoned on this same score. In the second case treated by manipulation by this surgeon, one of subclavian aneurysm, para- lysis of the left side of the body followed at once upon the first handling of the tumour. The pulsations of the brain may be communi- cated to any tumours or collections of fluid that reach the surface of the brain through an aper- ture in the skull. Such pulsations are synchron- ous with the arterial pulse, but the sphygmo- Ill] VESSELS OF THE BRAIN 49 graphic tracings of the cerebral pulsations exhibit also the " respiratory curve/' conveyed directly from the thorax by the blood within the veins. The valve at the lower end of the jugular vein prevents direct regurgitation of blood from the heart to the brain, but it does not prevent the transmission of pressure. Although wounds of the brain bleed freely, the bleeding is checked without difficulty, the vessels being capable of ready contraction. Large tumours have been excised from the cortex of the brain, without undue trouble from haemor- rhage. The terminal branches of the cerebral arteries anastomose freely in the pia mater, but the minute arteries which perforate and supply the cortex are terminal. Hence any pressure ap- plied to the surface of the brain will lead to anaemia of that piece of cortex, and, if the pres- sure is continued, to its destruction. Ligature of a cerebral vein usually leads to an atrophy of the cortex which it drains (Horsley). There is always one — sometimes more — anastomos- ing vein on the surface of the cerebrum, uniting the upper with the lower cerebral veins. The lower cerebral veins are four in number : three of them leave the temporal and occipital lobes to end in the lateral sinus; the other, the superficial Sylvian vein, ends in the sinus of the small wing of the sphenoid. The temporal and occipital lobes cannot be lifted off the tentorium without rup- turing the veins joining the lateral sinus. Nearly all the veins of the cerebellum end in the lateral sinus ; its arteries are derived from vertebral and basilar. Tumours in the cerebel- lum give rise to muscular weakness and inco- ordination, giddiness, and loss of balance. The vermis, or middle part of the cerebellum, is more directly connected with bending movements of the trunk, while the lateral lobes are concerned in the co-ordination of turning movements — move- ments made round the vertical axis of the trunk (Horsley). CHAPTER IV THE ORBIT AND EYE The Orbit The antero-posterior diameter of the orbit is about If inches (44 mm.), its vertical diameter at the base a little over lj inches (31 mm.), and its horizontal diameter at the base about lj inches (37 mm.). The diameters of the globe are as follow : transverse, 24 mm. ; antero- posterior, 24*5 mm. ; vertical, 23 mm. (Brailey). The eyeball is therefore nearer to the upper and lower margins of the orbit than it is to the sides, and the greatest interval between the globe and the orbital wall is on the outer side. The interior of the orbit is most con- veniently reached by incisions made to the outer side of the globe, and, in excision of the eyeball, the scissors are usually introduced on that side when the optic nerve has to be divided. In excis- ing the left eye, however, it may be more con- venient to divide the optic nerve from the inner side. The bones forming the floor, the roof, and the inner wall of the orbital cavity are very thin, especially in the last-named situation. Thus, foreign bodies thrust intp the orbit have readily penetrated into the cranial cavity, into the nose and ethmoidal cells, and, when directed from above, into the antrum. In several instances a sharp-pointed instrument, such as the end of a stick or foil, has been thrust into the brain 50 Chap. IV] ORBITAL WALLS 51 through the orbit, and has left but little external evidence of this serious lesion. Nelaton mentions a case in which the internal carotid artery was wounded through the orbit. Certain cases of pulsating orbital tumour which depend upon a communication between the carotid artery and the cavernous sinus have a traumatic origin. A reference to the relations of the orbital walls will show that a tumour may readily invade the orbit by spreading (1) from the base of the skull, (2) from the nasal fossae, (3) from the antrum, and (4) from the temporal or zygomatic fossse. In any of these instances the growth may enter the orbit by destroying the intervening thin layers of bone, and in tumours of the antrum this is the usual mode of entry. It may, however, ex- tend more readily from the cranial cavity through the optic foramen or sphenoidal fissure, from the nose through the nasal duct, and from the two fossse named through the spheno-maxillary fis- sure. After violent blows upon the temple, blood has found its way into the orbit through the spheno-maxillary fissure, and has led to subcon- junctival ecchymosis. Distension of the frontal sinus by retained mucus or pus may lead to a prominent tumour at the upper and inner margin of the orbit, above the level of the tendo oculi, which may cause displacement of the globe down- wards, outwards, and forwards. The bones of the orbit are peculiarly apt to be the seat of ivory exostoses, which may in time entirely occupy the orbital cavity. The anterior third of the outer wall of the orbit is separated from the temporal fossa by the malar (Fig. 14) ; the posterior two-thirds are separated by the great wing of the sphenoid from t the middle fossa of the skull, which contains the temporal lobe. Kronlein removes intraorbital tumours by opening the outer wall of the orbit in the temporal fossa. In a notori- ous case, in which a murderer attempted to commit suicide, the bullet entered the temporal 52 THE HEAD AND NECK [Chap. fossa, perforated the outer wall of the orbit, and destroved the eyeball, but left the brain un- touched. The pole of the temporal lobe is situ- ated from 2 to 2*5 cm. behind the outer margin of the orbit (see Fig. 3, p. 12). Capsule of Tenon.— The best description of this capsule has been given by Mr. Lockwood, Int. Tarsal Liq. Cach.Sac Ext- Tarsal LiCv Conjunctiva.^ Ext.Chcck. Int. Check Liq. -Capsul&ofTenon l/NT. R.ECTUS Optic /Iervb SrtEATM Fig. 14. — Showing the arrangement of the capsule of Tenon and check ligaments. The eyeball is turned outwards so that the external check ligament is taut and the internal relaxed. of whose researches Prof. Cunningham provides the following resume : — " The capsule is a firm loose membrane spread over the posterior f ths of the globe, the cornea alone being free from it. In front it lies under the ocular conjunctiva, with which it is intimately connected, and it ends by blending with that membrane close to the margin of the cornea (Fig. 14). ■IV] LIGAMENTS OF THE EYE 53 Behind it fuses with the sheath of the optic nerve, where the latter pierces the sclerotic. The surface of the membrane towards the globe is smooth, and is connected to the eyeball by some soft yielding areolar tissue. It thus forms a kind of dome for the globe, a species of socket or bursa in which it moves. The posterior surface of the capsule is in contact with the orbital fat. The tendons of the ocular muscles pierce the capsule opposite the equator of the globe (Fig. 14). The lips of the openings through which the four recti pass are prolonged backwards upon the muscles, in the form of sheaths, very much as the infundibulif orm fascia is prolonged upon the cord from the internal abdominal ring. ,, Where the internal and external recti per- forate, strong expansions of the capsule spread out to the inner and outer walls of the orbit. Because these expansions limit the action of the two recti they are known as the check ligaments (Fig. 14). They allow a side-to- side movement of the cornea to the extent of about 45°. The external check ligament is the stronger, and is attached to the outer wall im- mediately behind the external tarsal ligament; the attachment of the internal ligament is close behind the lachrymal sac. A prolongation of the capsule passes to the trochlea round the tendon of the superior oblique. The suspensory ligament of the eyeball stretches across the orbit like a hammock, supporting the eyeball. It is really a thickening of the under part of the capsule of Tenon, its attachment to the orbital walls being made by means of the internal and external check ligaments. When the upper jaw is removed the surgeon should take care to preserve the attach- ments of the suspensory ligament. If these be destroyed the eyeball will sink downwards. The intimate relation of the capsule of Tenon to the eyeball, conjunctiva, orbital muscles, and orbital walls has to be kept in mind where opera- tions are 'undertaken to remedy squint. From Fig. 14 it will be seen that after the tendon of a rectus muscle is cut through as it lies within the capsule of Tenon, the muscle still possesses, 54 THE HEAD AND NECK [Chap. through the continuity of its sheath with the cap- sule, an attachment to the eyeball and conjunc- tiva as well as to the orbital wall by the check ligament. Hence when the tendon of a muscle is completely cut it can still act on the eyeball ; its complete retraction is prevented by the check ligament. The orbit behind Tenon's capsule is occupied by a large quantity of loose fat, in addition to the ocular muscles, vessels, and nerves. It is by the absorption of this fat that the sunken eye is produced in cases of emaciation and prolonged illness. This tissue affords a ready means for the spread of orbital abscess. Such an abscess may follow > injuries, certain ocular inflammations, periostitis, etc., or may spread from adjacent parts. The pus may occupy the entire cavity, dis- placing the eyeball forwards, limiting its move- ments, and causing, by interference with the cir- culation, great redness of the conjunctiva and swelling of the lids. Foreign bodies, some of them of remarkable size and shape, have lodged for long periods of time in the orbital fat without causing much trouble. Thus Lawson reports a case where a piece of an iron hat-peg, three inches long, was embedded in the orbit for several days without the patient being aware of it. A stranger case, in some ways, is that reported by Furneaux Jordan : " A man who was employed in threshing became the subject of severe ophthalmia. At the expira- tion of several weeks, the patient, whilst pressing his finger on the lower eyelid, suddenly ejected from a comfortable bed of warm pus a grain of wheat, which had shot forth a vigorous green sprout. " The orbital fat affords also an excellent nidus for growing tumours. . Fractures of the inner wall of the orbit involving the nasal fossae or sinuses may lead to extensive emphysema of the orbital cellular tissue. The air so introduced may cause the globe to protrude, may limit its movements, may spread to the lids, and will, in IV] MUSCLES OF THE ORBIT 55 any case, be increased in amount by blowing the nose, etc. Orbital muscles. — The four recti muscles end in thin, flat membranous tendons. The ten- don of the external or internal rectus muscle is frequently divided for strabismus. The width of the tendons varies from 7 mm. to 9 mm. They are inserted into the sclerotic near the cornea. The internal rectus is inserted 6*5 mm. from the corneal margin, the external 6*8 mm., the inferior 7*2 mm., and the superior 8 mm. (Merkel). While the internal and external recti are pure internal and external rotators of the eyeball, the superior and inferior recti, owing to the line in Inf. Obliq. Inf. Obliq. R. Sup. R. Int. R. Int. R. Inf. Sup. Obliq. Sup. Obliq. R. Inf. Fig. 15. — Diagram to show the action of the orbi(al muscles The arrows show the direction of the action of each muscle. which they pull, act as internal as well as up- ward and downward rotators. Their tendency to act as internal rotators is counterbalanced by the two oblique muscles, which serve as external as well as upward and downward rotators. The diagram given in Fig. 15 will help to make the actions of the orbital muscles clearer. Conjugate horizontal movements to the right or left are executed by the internal and external rectus muscles. When the cornea is turned upwards the muscles in action are the inferior oblique and superior rectus, the first named tend- ing to turn the cornea towards the temporal as- pect, the second towards the nasal aspect. The two muscles involved in turning the cornea down- 56 THE HEAD AND NECK [Chap. wards are the inferior rectus and superior oblique, the first deflecting the movements towards the nasal side, the second towards the malar side. The diagram also serves to show the muscles of the right and left sides, which are co-ordinate in conjugate movements. Thus, in turning the eyes downwards and to the right, the superior oblique of the right side acts with the inferior rectus of the left. If one of these muscles is paralysed, then double-vision or diplopia occurs when this movement is carried out. The orbital arteries are small, and seldom give rise to trouble when divided in excising the globe, since they can be readily compressed against the bony walls of the cavity. Pulsating tumours of this part may be due to^ traumatic aneurysms of one of the orbital arteries, or may depend upon an arterio-venous aneurysm formed between the internal carotid artery and the cavernous sinus. Pressure also upon the ophthal- mic vein (as it enters the sinus) by an aneurysm of the internal carotid vessel may produce all the symptoms associated with pulsating orbital tumours. Thrombosis of the cavernous sinus causes dilatation of the ophthalmic veins and proptosis. The orbital nerves may be damaged in wounds of the orbit, or in fractures of the orbit and of the base of the skull. They may be pressed upon by tumours from various parts, by aneu- rysms, hsemorrhagic and inflammatory effusions. Thus, Lawson records a case in which the optic nerve was divided by a stab through the upper eyelid, without the globe being injured, and with- out any bone being fractured. The same nerve has also been completely torn across in fractures of the orbit, and has been pressed upon in frac- tures involving the lesser wing of the sphenoid. The^ third, fourth, and sixth nerves, and the first division of the fifth, may be affected in cases of aneurysm involving the internal carotid artery, where they lie in relation with the cavernous IV] PARALYSIS OF ORBITAL NERVES 57 sinus. They may readily be pressed upon, also, by any growth involving the sphenoidal fissure, such as a periosteal node springing from the mar- gin of the fissure, while the sixth nerve, from its more intimate connexion with the base of the skull, has been directly torn across in a fracture involving that part (Prescott Hewett). In paralysis of the third nerve there is droop- ing of the upper lid (ptosis) ; the eye is almost motionless, presents a divergent squint from unopposed action of the external rectus muscle, and cannot be moved either inwards, upwards, or directly downwards. Rotation, in a direc- tion downwards and outwards, can still be effected by the superior oblique and outer rectus muscles. The pupil is dilated and fixed; the power of accommodation is much impaired, there is diplopia, and sometimes a little protrusion of the globe from relaxation of the recti muscles. These symptoms refer to complete paralysis of the nerve. In cases of partial paralysis, only one or two of the above symptoms may be present. In paralysis of the fourth nerve there is often but little change to be seen, since the func- tion of the superior oblique muscle, supplied by this nerve, may, in part, be performed vicari- ously. " There is usually only very slight defect in the mobility of the eye; what there is occurs chiefly; in the inner and lower angle of the field of vision; there is deviation of the eye inwards and upwards on lowering the object, and simply upwards when it is turned far towards the healthy side " (Erb). In any case there will be diplopia, especially in certain positions of the globe. In paralysis of the sixth nerve there is con- vergent strabismus, with consequent diplopia, and an inability to rotate the eye directly out- wards. Paralysis of the sixth nerve may be ac- companied by paralysis of the nerve to the in- ternal rectus of the opposite side, giving rise to conjugate deviation of the eyes. Such a condi- tion indicates a lesion in the nucleus of the sixth 58 THE HEAD AND NECK [Chap. nerve, for although the fibres for the internal rectus pass out with the third nerve they take their origin with the sixth. Sometimes all the oculo-motor nerves of the eye are paralysed, and in such cases the lesion is ■ probably situated either at their nuclei of origin or at the cavernous sinus, in the wall of which the nerves lie close together. In paralysis of the first division of the fifth there is a loss of sensation in all the conjunctiva, except such as covers the lower lid (supplied by the palpebral branch of the infraorbital nerve), loss of sensation in the globe, and in skin sup- plied by the supratrochlear and supraorbital nerves, and in the mucous and cutaneous surfaces supplied by the nasal nerve. The area of anaes- thesia is much less than the anatomical distri- bution of the nerve, owing to the extent to which cutaneous nerves overlap. No reflex movements (winking) follow upon irritation of the conjunc- tiva, although the patient can be made to wink on exposing the eye to a strong light, the optic nerve in this case transmitting the impression to the facial nerve. Sneezing also cannot be ex- cited by irritating the mucous membrane in the anterior part of the nose. Destructive ulceration of the cornea may follow this paralysis, due partly to damage to the trophic branches con- tained in the paralysed nerve, partly to the anaes- thesia which renders the part readily injured, and partly to the loss of the reflex effect of the sensory nerves upon^ the calibre of the blood-vessels, whereby the inflammation is permitted to go un- controlled (Nettleship). In paralysis of the cervical sympathetic there is narrowing of the palpebral fissure from some drooping of the upper lid, apparent recession of the globe within the orbit, and some narrow- ing of the pupil from paralysis of the dilator muscle of the iris, which muscle is supplied by the sympathetic. The drooping of the upper lid may be explained by the fact that each eyelid contains IV] THE EYE 59 a layer of unstriated muscle fibre. That in the upper lid arises from the under surface of the levator palpebrse, and is attached to the tarsal cartilage near its upper margin (Fig. 18, p. 76). This layer of muscle, which, when in action, would keep up the lid, is under the influence of the cervical sympathetic. The recession of the globe is supposed by some to be due to paralysis of the orbitalis muscle of H. Muller. This muscle bridges over the spheno-maxillary fissure, is com- posed of unstriated fibres, and is innervated by the sympathetic. Contraction of the muscle (as pro- duced by stimulation of the cervical sympathetic in animals) causes protrusion of the globe, while section of the sympathetic in the neck produces retraction of the eyeball (Claude Bernard). No changes are observed in the calibre of the blood- vessels of the globe. The non-striated muscle maintains the intraorbital pressure, and thus assists in the return of blood from the ophthalmic veins. In animals such as the ox, in which the veins of the orbit become dilated when the head is carried low, as in browsing, this musculature attains a great development. The Globe The cornea. — The thickness of the cornea varies from 0'9 mm. in the central parts to 1*1 mm. at the periphery. One is apt to be a little deceived as to its thickness, and on intro- ducing a knife into the cornea, the instrument, if not entered atthe proper angle, may be thrust for some little distance among the laminae of the part. In front the cornea is covered by stratified epithelium. When this layer has been removed by abrasion, a white deposit of lead salts may take place in the exposed corneal tissue in cases where lead lotions are used. The bulk of the cornea is made up of a great number of fibrous lamellae, between which are anastomosing cell spaces containing the corneal corpuscles. If the 60 THE HEAD AND NECK [Chap. nczzle of a fine syringe be thrust into the corneal tissue, the network of cell spaces can be filled with injection (Recklinghausen's canals). When suppuration takes place within the proper corneal tissue, it is probably along these canals, modified by inflammation, that the pus spreads, thus producing onyx. The cornea contains no trace of blood-vessels, except at its extreme peri- Fig. 16. — Horizontal section of the globe through the middle. a, Cornea : &, sclerotic ; c, choroid ; <7, retina ; e, lens ;/, iris ; g, ciliary process and muscle ; h, canal of Schlemm. phery, where the capillaries of the sclerotic and conjunctiva end in loops. This lack of a direct blood supply renders the cornea prone to inflame spontaneously in the cachectic and ill-nourished. When inflamed, the tissue always becomes opaque. In the affection known as interstitial keratitis, blood-vessels from the arteries of the margin of the cornea penetrate into the substance of the IVJ THE CORNEA 61 cornea for some distance. As these vessels are some little way below the surface, and are covered by the hazy corneal tissue that is the re- sult of the disease, their scarlet colour is much toned down, and a strand of such vessels is called a "salmon patch." In the condition known as pannus, the cornea appears to be vascularized ; but here, owing to continued irritation, vessels, derived from the neighbouring conjunctival arteries, pass over the cornea just beneath its epithelial covering, leaving the cornea proper as bloodless as ever. The term arcus senilis is ap- plied to two narrow white crescents that appear at the periphery of the cornea, just within its margin, in the aged, and in certain morbid con- ditions. The crescents are placed at the upper and lower margins, and their points meet midway on either side of the cornea. They are due to fatty degeneration of the corneal tissue, and the change is most marked in the layers of the cornea just beneath the anterior elastic lamina, i.e. in the part most influenced by the marginal blood- vessels. In spite of its lack of a direct blood supply, wounds of the cornea heal kindly. The cornea is very lavishly supplied with nerves, estimated to be from forty to forty-five in number. They are derived from the ciliary nerves, enter the cornea through the fore part of the sclerotic, and are distributed to every part of the tunic. In glaucoma, a disease of which the phenomena depend upon greatly in- creased intraocular pressure, the cornea becomes anaesthetic. This depends upon the pressure to which the ciliary nerves are exposed before their branches reach the cornea. (See also Nerve Supply of the Eyeball, p. 66.) Sclerotic, choroid, and iris.— The sclerotic is thickest behind, and thinnest about J of an inch from the cornea. When the globe is rup- tured by violence it is the sclerotic that most commonly yields, the rent being usually a little way from the cornea, i.e. in or about the 62 THE HEAD AND NECK [Chap, thinnest part of the tunic. A rupture of the cornea alone from violence is not common. The sclerotic may be ruptured while the lax conjunc- tiva over it remains untorn. In such a case the lens may escape through the rent in the sclerotic, and be found under the conjunctiva. At the point of penetration of the optic nerve the sclerotic is thin, and pierced by numerous holes for the pas- sage of nerve bundles. This weakened portion, the lamina cribrosa, plays an important part in glaucoma (p. 74). It gjives the stippled appear- ance to the optic papilla. Brailey states that the lateral parts of the sclerotic are thinner than the upper and lower segments, the inferior part being the thickest and the external wall the thin- nest. It happens, therefore, that under the influ- ence of intraocular pressure the eye expands more laterally than in the vertical direction. It is mainly to the tenseness and unyielding character of the sclerotic that must be ascribed the severe pain (due to pressure on nerves) experienced in those eye affections associated with increased intra- ocular tension (glaucoma, etc.). The choroid is the vascular tunic of the globe, and carries its main blood-vessels. Between the choroid and sclerotic are two thin membranes, the lamina suprachoroidea and lamina fusca, which are separated^ from one another by a lymph space. In injuries to the globe, therefore, ex- tensive bleeding may take place between these two coats, and indeed a like haemorrhage may be the result simply of a sudden diminution in the ocular tension produced by such an operation as iridectomy or cataract extraction. The choroid alone has been ruptured (usually at its posterior part) as the result of a, blow upon the front of the eye. The choroid is one of the few parts of the body that may be the seat of melanotic growths. These growths are sarcomatous tumours containing a large amount of pigment, and occur only where pigment cells are found. In the choroid coat pigment cells are very abundant. IV] THE IRIS 63 The iris is, from its great vascularity, very easily inflamed. From its relations to the cornea and sclerotic it happens that inflammation in those tunics can spread without difficulty to the iris. On the other hand, the vessels of the^ iris and choroid are so intimately related that inflamma- tions set up in the iris itself have every induce- ment to spread to the choroidal tunic. When the iris is inflamed its colour becomes altered, owing to the congestion of the part and to the effusion of lymph and serum that takes place in its substance. The swelling to which it becomes subject, together with the effusion, produce a blurring of its delicate reticulated structure, as seen through the cornea. Owing also to the swollen condition of the little membrane, the pupil becomes encroached on, and appears to be contracted, while the move- ments of the membrane are necessarily rendered very sluggish. If it be remembered that part of the posterior surface of the iris is in actual contact with the lens capsule, it will be understood that inflammatory adhesions may readily take place between the two parts (Fig. 16). After iritis, therefore, it JUj common to find the posterior sur- face of the iris (most often its pupillary margin) adherent to the lens capsule by bands of lymph, either entirely or in one or more^ different points. Such adhesions constitute^ posterior synechias, the term anterior synechise being applied to adhesions between the iris and the cornea. In iritis also the^ lens may become involved, and the con- dition of secondary or inflammatory cataract be produced. The iris is not very closely attached at its insertion (Fig. 17). Thus, in the case of injury to the eye, it may be torn more or less from its attachments without any damage being done to the other tunics. The iris has been com- pletely torn away in a few instances, and has escaped through a wound of the globe. The ciliary processes have been thus exposed. Con- genital absence of the iris has been recorded. 64 THE HEAD AND NECK [Chap. In cases of penetrating wounds of the cornea the iris is easily prolapsed. It is so delicate and yield- ing a membrane that in performing iridectomy the necessary piece of the iris can be seized and pulled out through the corneal incision without offering sensible resistance. The membrane also derives much support from its contact with the lens, for in cases where the lens has been displaced into the vitreous, or has been removed by operation, the iris is observed to be tremulous when the globe is moved. Although very vascular, the iris seldom bleeds much when cut, a circumstance that is pro- bably due to the contraction of the muscular fibres that exist so plentifully within it. Sometimes the iris presents in its substance a congenital gap that runs froin the pupil downwards and a little in- wards. This condition is known as coloboma iridis, and is due to the persistence of the " choroidal cleft " formed during development of the optic cup. In other cases there can be seen, stretch- ing across the pupil, some shreds of the pupillary membrane. Normally this membrane, which is ap- parent for a few days after birth in some animals, is entirely absorbed before birth. It will now be convenient to take note of the blood and nerve supply of the globe. Blood supply of the eyeball. — 1. The short ciliary arteries (from the ophthalmic) pierce the sclerotic close to the optic nerve, run some little way in the outer coat of the choroid, and then break up into a capillary plexus that makes up the main part of the inner choroidal coat. In front this plexus gives some vessels to the ciliary processes. The veins from these vessels are disposed in curves as they converge to four or five main trunks (venae vorticosse), which pierce the Sclerotic midway be- tween the cornea and the optic nerve. In the choroid they lie externally to the arteries. 2. The two long ciliary t arteries (from the ophthalmic pierce the sclerotic to the outer side of the optic nerve and run forwards, one on either side, until they reach the ciliary region, where they IV] VESSELS OF THE EYEBALL 65 break up into branches that, by anastomosing, form a vascular circle about the periphery of the iris (the circulus major). From this circle some branches pass to the ciliary muscle, while the rest run in the iris in a converging manner towards the pupil, and at the margin of the pupil form a second circle (the circulus minor). 3. The anterior ciliary arteries (from the mus- cular and lachrymal branches of the ophthalmic) pierce the sclerotic (perforating branches) about 2-3 mm. behind the cornea, join the circulus major, and give off branches to the ciliary pro- cesses, where they form copious anastomosing loops. These arteries lie in the subconjunctival tissue. Their episcleral or non-perforating branches are very small and numerous, and are invisible in the normal state of the eye. In inflammation of the, iris and adjacent parts, however, these ves- sels appear as a narrow pink zone of fine vessels round the margin of the cornea, that run nearly parallel to one another, are very closely set, and do not move with the conjunctiva. This zone is known as the zone of ciliary congestion, or the cir- cumcorneal zone. 4. The vessels of the conjunctiva are derived from the lachrymal and the two palpebral arteries. These vessels, in cases of inflammation, are readily distinguished from those last described. They are of comparatively large size, are tortuous, are of a bright brick-red colour, can be easily moved with the conjunctiva, and as easily emptied of their blood by pressure. The differences presented by these two sets of vessels serve in one way to dis- tinguish inflammation of the conjunctiva from that involving deeper parts. The conjunctival vessels around the margin of the cornea form a closer plexus of anastomosing capillary loops, which be- come congested in severe superficial inflammation of the cornea, and may then form a zone around the margin of the cornea, which can, however, be distinguished from the " ciliary zone " by the general characters just named. The retina has a D 66 THE HEAD AND NECK [Chap. vascular system^ of its own, supplied through the arteria centralis retinae, which is nowhere in direct communication with the choroidal vessels, except just at the entrance of the optic nerve. Indeed, the outer layers of the retina which are in relation with the choroid coat are entirely destitute of vessels. Thus, when the central artery of the retina becomes plugged, sudden blindness follows, and as the meagre collateral circulation that is established by the minute anastomoses about the entrance of the nerve is quite insufficient, the re- tina soon becomes cedematous. A permanent plug- ging of the central artery means, therefore, a prac- tical extinction of the vascular system of the re- tina. In some cases of embolism, only a branch of the retinal artery is plugged, the patient retaining vision except in that par.t of the retina supplied by the branch. The fovea centralis, the centre of acute vision, receives twigs from both the superior and inferior temporal branches of the arteria centralis retinae. In cases of haemorrhage between the choroid and retina the blood must come from the choroidal vessels ; and in haemorrhage into the vitreous, which often follows injury, the blood may be de- rived from the retinal vessels, since they run in the inner layers of that membrane, or from the vessels in the ciliary region. Nerve supply of the eyeball. — l. The cili- ary nerves derived from the lenticular ganglion and the nasal nerve pierce the sclerotic close to the optic nerve, and pass forwards between the sclero- tic and the choroid, supplying those parts. They enter the ciliary muscle, form a plexus about the periphery of the iris, and then send fibres into the iris, which form a fine plexus as far as the pupil. They send branches through the fore part of the sclerotic to the cornea. Thus the eye- ball obtains through these nerves its sensory fibres from the nasal branch of the first division of the fifth, its motor fibres for the ciliary muscle and sphincter iridis from the third nerve, and many IVj NERVES OF THE EYEBALL 67 sympathetic fibres, among which are those that supply the dilator muscle of the iris. 2. The conjunctiva is supplied by four nerves : above, the supratrochlear; inner side, the infra- trochlear; outer side, the lachrymal (all branches of the first division of the fifth) ; below, the palpe- bral branches of the second division of the fifth. As the ciliary nerves pass forwards between the choroid and the sclerotic, it will be seen that they are readily exposed to injurious pressure against the unyielding sclerotic in cases of increased intra- ocular tension. The sensation of the globe itself is derived solely from the first division of the fifth. In inflammatory affections of the globe, as in corneitis or iritis, be- sides the pain actually felt in the eye, there is pain referred along other branches of the first division of the fifth. The explanation of this fact has to be sought for in the common origin of the ophthalmic division from the upper sensory nucleus of the fifth nerve in the floor of the fourth ventricle. Not only are the nerve cells connected with the eyeball disturbed, but the neighbouring cells also are affected, and by a psychical error the pain is reflected along the nerves with which they are connected. There is pain over the fore- head along the supratrochlear, the supraorbital, and the lachrymal branches (circumorbital pain), and pain down the side of the nose following the nasal nerve. Or the pain may spread to the second division of the fifth, and discom- fort be felt in the temporal region (orbital branch of second division), or be referred to the upper jaw and teeth. These affections are associated also with much lachrymation, the lachrymal gland being also supplied through the first division of the fifth. Photophobia, or intoler- ance of light, is common in inflammatory affec- tions of the eye. In this condition there is spasm of the orbicular muscle, keeping the eye closed, or closing it on the least exposure to irritation. Although the orbicular muscle is supplied by the 68 THE HEAD AND NECK [Chap. facial nerve, its nerve fibres are derived, not from the nucleus of the seventh but from the oculo- motor nucleus, situated near the upper sensory nucleus of the fifth, and connected with it by reflex paths. Photophobia is most marked in superficial affections of the cornea, and is often much benefited by a seton in the temporal region. Inflammation of the iris and glaucoma are accom- panied by hyperesthesia and referred pains over the outer frontal and anterior temporal areas (Head). The nerve centres for the skin of this region and the eyeball are closely connected, a relationship which may explain the application of counter-irritation to the temples in eye disease. Inflammation of the cornea gives rise to no referred pains (Head). Strain of the ciliary muscle, which occurs with errors of refraction, is one of the commonest causes of headache leading to referred pains and areas of hyperesthesia over the midorbital region of the forehead. The relations between the nasal nerve and the orbital contents receive many illustrations in prac- tice. Thus, if the front of the nose be struck, or the skin over its lower part be irritated, as by squeezing a painful boil, profuse lachrymation will frequently be produced. Snuff, too, by stimulating the nasal branch of the ophthalmic nerve, often makes the eyes of the uninitiated to water ; and it is well known that there are many disturb- ances about the nose, and the anterior part of the nasal fossae, that can "make the eyes water.' ' Herpes zoster often provides a remarkable illus- tration of the intimate relation between the nasal nerve and the eye. In this affection, when the regions of the supraorbital and supratrochlear branches of the first division are alone implicated, the eye is usually unaffected; but when the erup- tion extends over the part supplied by the nasal nerve, i.e. runs down the side of the nose, then there is very commonly some inflammation of the eyeball. Dangerous area of the eye.— Penetrating IV] DANGER AREA OF THE EYE 69 wounds of the cornea alone, or of the sclerotic alone, behind the ciliary region, are by no means serious; but wounds involving the ciliary body, or its immediate vicinity, are apt to assume the gravest characters. Inflammation in the ciliary region is peculiarly obnoxious, on account of the important vascular and nerve anastomoses that take place in the part. Indeed, as regards blood and nerve supply, there is no more important district in the eyeball. From the ciliary body also inflammations can spread, more or less directly, to the cornea, iris, choroid, vitreous, and retina. Plastic, or purulent, inflammation of the ciliary body, after injury, is the usual starting- point of sympathetic ophthalmia. In this ter- rible affection destructive inflammation is set up in the sound eye, which is, however, not usually involved until two or three months after the other eye has been injured. " Although at present the exact nature of the process which causes sym- pathetic inflammation is unknown, and though its path has not been fully traced out, it is cer- tain (1) that the change starts from the region most richly supplied by branches of the ciliary nerves, viz. the ciliary body and iris; (2) that its first effects are generally seen in the same part of the sympathizing eye ; (3) that the exciting eye has nearly always been wounded, and in its anterior part, and that decided plastic inflammation of its uveal tract is always present; (4) that inflamma- tory changes have in some cases been found in the ciliary nerves and optic nerve of the exciting eye ;; (Nettleship). It is now generally believed that the sound eye is directly infected from the diseased one. The subarachnoid spaces which sur- round the optic nerves are in continuity at the chiasma, and offer a path whereby infection may spread from one eye to the other. The lens measures J of an inch from side to side, and I of an inch from before backwards. All through life it slowly increases in size. It, together with its capsule, is in all parts per- 70 THE HEAD AND NECK [Chap. fectly transparent and perfectly non-vascular. The manner in which the lens is maintained in position is shown in Fig. 17. The circumference of the lens is fixed to the ciliary processes by a system of fine, transparent, radial fibres (the suspensory ligament of the lens), some of which pass in front of the lens, while others pass behind it, thus forming a sac or capsule for the lens. On the ciliary processes the radial fibres of the suspensory ligament become continuous with the transparent capsule of the vitreous humour — the hyaloid membrane. The lens may easily be loosened or displaced by partial rupture of its suspensory ligament, and may find its way into the anterior chamber, or, more commonly, back into the vitreous. The lens, if disturbed, may swell, and by the pressure thus exercised cause great damage to the important structures adjacent to it. The capsule is very brittle and elastic, and when torn its edges curl outwards. It is lacerated in the usual operations for cataract, and may be ruptured by many forms of violence applied to the eyeball. ^ " In one form of cataract operation the capsule is removed with the lens, the vitreous being retained in position by the hyaloid membrane which lies behind the capsule of the lens" (Lieut.-Colonel H. Smith). When the capsule is wounded the aqueous humour enters, and is imbibed by the lens fibres, which in conse- quence swell up and become opaque, thus produc- ing a traumatic cataract. In the various forms of cataract the whole lens, or, more commonly, some portion of it, becomes the seat of opacity. This often commences in the nucleus, and for a long while remains limited to that part; or it may first involve the cortex, and in such a case the opacity takes the form of a series of streaks that point towards the axis of the lens, and are dependent upon the arrangement of the lens fibres. Of the retina it is only necessary^ to observe that its connexion with the choroid is so slight IV] THE EETINA 71 that it may easily be detached from that mem- brane by hemorrhagic or other effusions, and may indeed be so detached by a simple blow upon the globe. Even when extensively detached it remains, however, as a rule, attached at both the optic disc and the or a serrata. The length of the optic nerve within the orbit is 28-30 mm. As it passes from the brain it receives its perineural sheath from the pia mater, and, in addition, two other sheaths : an outer from the dura mater, and an inner from the arachnoid. These sheaths remain distinct and separate, and the two spaces enclosed may be in- jected, the outer from the subdural, the inner from the subarachnoid space. Thus inflammatory affec- tions of the cerebral meninges can readily extend along the optic nerve to the optic disc through these spaces in the nerve sheath, while in cases of intracranial disease other than meningeal the mischief may extend from the brain to the disc along the interstitial connective tissue in the nerve. These connexions may serve in part to explain the frequent association of optic neuritis with intra- cranial disease. As the nerve leaves^ the skull in the optic foramen it is in contact with the outer wall of ^ the sphenoidal sinus, or, if that sinus be relatively small, with the posterior ethmoidal cells. In suppuration of these spaces infection may spread to the optic nerve, and thus set up optic neuritis. Optic neuritis usually implies that the optic disc or papilla is inflamed, but in exceptional cases the changes are limited to that part of the nerve behind the globe (retrobulbar neuritis). Aqueous and vitreous humours.— The aqueous fills the space between the capsule and suspensory ligament of the lens and the cornea. The iris divides this space into two parts, the an- terior and posterior chambers. Since, however, the iris is largely in actual contact with the lens, it happens that . the posterior chamber is repre- sented by a little angular interval between the 72 THE HEAD AND NECK [Chap. iris, the ciliary processes, and the suspensory ligament of the lens (Fig. 17). The depth of the anterior chamber is 3*6 mm. The inner stratum of the cornea, as it becomes continuous with the sclerotic, splits up into fibres which pass to (1) the sclerotic, (2) the ciliary muscle, (3) the ciliary processes. The fibres form the ligamentum pectinatum, and the intervals between its fibres Canal of Schlemm Pectinate Liq. Ciliary Muse. (f — lens Fig. 17. — Ligamentum pectinatum, spaces of Fontana, ciliary muscle, and capsule of the lens. (After Fuchs.) are known as the spaces of Fontana. They are filled by the aqueous humour. These spaces in their turn communicate with a venous circular canal situate in the sclerotic close to its junction with the cornea, and known as the canal of Schlemm (Fig. 17). This canal is in communica- tion with the veins of the anterior part of the sclerotic, ciliary processes and iris. The aqueous humour passes from the spaces of Fontana into IV] xlQUEOUS AND VITREOUS HUMOURS 73 the canal of Schlemm, and thus into the venous circulation. This relation probably explains the ready absorptive powers of the aqueous. Thus, if pus finds its way into the anterior chamber (hypopyon) it is, as a rule, easily absorbed. The same applies to moderate extravasations of blood in the chamber, and the speedy removal of such effusions contrasts with the difficulty that is ex- perienced in the absorption of blood from the vitreous chamber. Professor Arthur Thomson has recently shown that the inner aspect of the sclerotic is depressed or grooved at the anterior base of the iris. When the pupil is dilated the contracted base of the iris tends to fill this groove, thus rendering the escape of the aqueous humour into the spaces of Fontana more difficult. The vitreous takes little active share in ocular maladies. It may be secondarily affected in in- flammation of adjacent parts, may be the seat of haemorrhages, and is often occupied by opaque bodies of various kinds. Foreign bodies have lodged in the vitreous for considerable periods without causing any symptoms. The muscse volitantes that so often trouble the myopic are due to little opaque matters in the vitreous, and very often have exactly the appearance that the corpuscles of the vitreous present when seen under the microscope. The delicate transparent membrane which en- capsules the vitreous humour is known as the hyaloid membrane. The vitreous is readily separ- ated from the retina except behind, opposite the disc where the artery to the lens enters in the foetus and passes forwards to supply the foetal pupillary membrane. This vessel is a branch of the central artery of the retina, and may persist as a fibrous cord in adult life. In some rare cases it has continued to transmit blood, and in such instances its pulsation can be seen with the ophthalmoscope. Glaucoma is a disease the symptoms of which D* 74 THE HEAD AND NECK [Chap. are all dependent upon an increase in the intra- ocular tension of the globe. The increased tension is due to an excess of fluid within the eyeball, and this would appear to result from certain changes, seldom absent in the glaucomatous, that interfere with the normal escape of this fluid. Normally there is a constant movement of fluid, through the pupil from the posterior to the anterior chamber. This fluid is derived mainly from the ciliary bodies, and in a less degree from the posterior surface of the iris. Atrophy of the epithelium on the ciliary body is said to lead to diminished tension. From the anterior chamber the fluid can escape into the veins through the gaps in the ligamentum pecti- natum already alluded to (Fig. 17). It is remark- able that in nearly every case of glaucoma these gaps are occluded by the complete obliteration of the angle between the periphery of the iris and the cornea, which angle is normally occupied by the ligamentum pectinatum. The importance of the peripheral part of the anterior chamber in relation to the outflow of fluid from the eye is shown in many ways. If this part be blocked by the iris in perforation of the cornea, or by the lens in some dislocations of that body, increased tension of the globe is apt to follow. The relief given to glaucoma by iridectomy appears to depend upon the circum- stance that the operation practically opens up again these channels of communication from the aqueous, since the procedure, to be successful, should involve an incision so far back on the sclero- tic as fully to pass through the angle just alluded to. It is needful also that the iris should be re- moved quite up to its attachment, and that the portion resected should be considerable. Iridec- tomy also exposes a fresh capillary surface of the iris to the aqueous humour, which thus finds a fresh exit. In the young the ligamentum pectinatum is cellular and open in structure ; it becomes fibrous and contracted in the old. Hence the aged are more liable to glaucoma (T. Henderson). . IV] GLAUCOMA 75 The symptoms of glaucoma are all explained by the effects of the abnormal tension. Thus^ the ciliary nerves are compressed against the unyield- ing sclerotic, and give rise to intense pain, while the disturbance in their functions shows itself in the fixed and dilated pupil and in the anaes- thetic cornea. Perhaps the first parts to suffer from compression are the retinal blood-vessels, and the effect upon them will be most obvious at the periphery of the retina, i.e. at the extreme limit of the retinal circulation. Hence follows that gradual narrowing of the visual field which is constant in glaucoma, while the pressure upon the optic nerve produces those flashes of light and other spectra which occur in the disease. The weakest part of the sclerotic is in the disc at the lamina cribrosa. This part rapidly yields under the pressure, and so produces the "glaucomatous cup." Pressure in the opposite direction pushes the lens forwards, and thus narrows the anterior chambers; while the general interference with the ocular circulation is shown in the distended vessels that appear upon the globe. The eyelids (Fig. 18). — The skin over the eye- lids is very thin and delicate, and shows readily through its substance any extravasation of blood that may form beneath it. Its laxity, moreover, renders it very .well adapted for certain plastic operations that are performed upon the part. Its loose attachments cause it to be readily influenced by traction, and the shrinking of cicatrices below the lower lid is very apt to draw that foM away from the globe, and so produce the condition of eversion of the lid known as ectropion. The con- traction of the conjunctiva after inflammatory con- ditions, or after it has been subjected to destructive agencies, is prone, on the other hand, to curl either lid inwards towards the globe, and thus to produce entropion. The lids present many transverse folds ; one of these on the upper lid, deeper and more marked than the rest, divides the lid into 76 THE HEAD AND NECK [Chap. two parts, the part below being that which covers the globe, the part above being that in relation with the soft structures of the orbit. In emaciation the lid becomes much sunken in the line of this fold. Incisions should follow the direction of the fold. The lids are very freely sup- plied with blood, and are often the seat of nsevi and other vas- cular growths. The following layers are found in either lid in order : (1) the skin ; (2) the subcu- taneous tissue ; (3) the orbicularis palpebra- rum ; (4) the tarsal plate and its continua- tion to the margin of the orbit — the palpe- bral membrane ; (5) the layer of Meibomian glands embedded in the plate; and (6) the conjunctiva. In the upper lid the levator palpebrse is found passing to the tarsal plate. The subcuta- neous tissue is very lax, and hence the lids swell greatly when cedematous, or when inflamed, and when On this account it leeches to the lids, '* 9 Fig. 18. — Vertical through upper eyelid. Waldeyer.) section (After a, Skin ; b, orbicularis ; V, its ciliary- part ; c, involuntary muscle of eyelid representing part of the insertion of the levator palpe- brse ; d, conjunctiva ; e, tarsal cartilage ; /, Meibomian gland ; g, modified sweat-gland ; h, eye- lashes ; i, post-tarsal glands. the seat of haemorrhage, is inadvisable to apply IV] EYELIDS— CONJUNCTIVA 77 because of the extensive "black eye" that may follow. This tissue is peculiar in containing no fat. At the edge of the lids are found the eye- lashes, the orifices of the Meibomian glands, and of some modified sweat- and sebaceous glands. The secretion of these glands prevents adhesion of the edges of the lid. This edge, like other points of junction of skin and mucous membrane, is apt to be the seat of irritative affections. As it is a free border also the circulation is terminal, and stagnation in the blood current is not difficult to produce. Sycosis, an inflammation involving the hair-follicles, and some of the glands at the edge of the lid, is among the most common of ophthal- mic affections. The common stye also is a sup- puration in the connective tissue or in one of the glands at the., margin. On everting the lid the Meibomian glands can be seen through the conjunctiva as lines of yellowish granules. The common tarsal cyst is a retention cyst developed in one of these glands. Two arteries supply either lid : a palpebral branch of the ophthalmic running along the inner part, and a branch of the lachrymal along the outer part of each lid. Four nerves supply the upper eyelid, the supraorbital, the supratrochlear and infratrochlear, and the lachrymal. One nerve supplies the lower lid, the infraorbital. Some of the lymphatics of the eyelids enter the pre- auricular glands, hence in cases of chancre of the lid the glandular enlargement has nearly always been noticed in front of the parotid gland. (Fig. 44, p. 197.) The conjunctiva. — The ocular part of this membrane is thin, covered with stratified epithe- lium very loosely attached, and not very exten- sively supplied with blood; the palpebral portion is thicker, covered with columnar epithelium more closely adherent, and more vascular. At the edge of the cornea the conjunctiva becomes continuous with the epithelium covering that tunic. The loose- ness of the ocular conjunctiva allows it to be freely 78 THE HEAD AND NECK [Chap. moved about, and is of great value in some opera- tions, as, for example, in Teale's operation for symblepharon, where a bridge of conjunctiva, dis- sected up from the globe above the cornea, is drawn down over the cornea to cover a raw surface in con- tact with the lower lid. This lax tissue favours the development of oedema (chemosis), which in ex- treme cases may reach such a degree that the patient cannot close his eye. The vessels also, being feebly supported, are prone to give way under no great provocation. Thus, subconjunc- tival haemorrhages may occur from severe vomit- ing, or durinig a paroxysm of whooping cough. Blood also may find its way beneath the membrane in fractures of the base of the skull. Haemorrhages beneath the membrane are unlike other extravasa- tions (bruises), in that they retain their scarlet colour. This is due to the fact that the thinness of the conjunctiva allows oxygen to reach the blood and gives it an arterial character. Severe inflammation of the conjunctiva may lead to con- siderable cicatricial changes, as is the case in other mucous membranes, and especially, perhaps, ( in the urethra. The contraction of the conjunctiva after destructive processes is apt to lead to en- tropion. If both the ocular and the corresponding part of the palpebral conjunctiva have been de- stroyed, the two raw surfaces left will readily ad- here ; the lid will become fused to the globe, and the condition called symblepharon be produced. This condition concerns the lower lid, and is gener- ally brought about by lime or other caustics bein^ accidentally introduced between the under lid and the globe. In one common form of inflammation of this membrane a number of little " granulations " ap- pear upon the palpebral conjunctiva. These are not real granulations, since no true ulceration of the part takes place, but they appear to be made up, some of nodules of adenoid tissue, others^ of enlarged mucous follicles and of hypertrophied papillae, all of which structures are normally found IV] LACHRYMAL APPARATUS 79 in the membrane. The condition is known as "granular lids," and is associated with the form- ation of much new tissue in the deeper parts of the membrane. From the absorption of this new tissue and of these granulations a contracting cica- trix results, leading to much puckering of the membrane, and often to entropion and inversion of the eyelashes. In purulent ophthalmia the cornea is in great risk of destruction, owing to the strangulation of its vessels and possibly to the direct effects of the discharge upon the membrane. Lachrymal apparatus. — The lachrymal gland is invested by a special fascia which separates it from the general cavity of the orbit; and, according to Tillaux, this little body can be removed without opening the greater space of the orbit. The gland may inflame, and become so en- larged as to appear as a tumour, which may dis- place the globe downwards and inwards, and press forwards the oculo-palpebral fold of conjunctiva. If an abscess forms, it most usually breaks through the skin of the upper lid. Cyst® of the gland (dacryops) are due to obstruction and distension of some of its ducts. The normal secretion of the gland keeps the exposed surface of the eye moist, yet the gland may be excised without giving rise to any untoward effect. The lachrymal sac is situated at the side of the nose, near the inner canthus, and lies in a groove on the lachrymal and superior maxillary bones (Fig. 19). On its outer side, and a little anteriorly, it receives the two lachrymal canaliculi. In front of the sac is the tendo bculi. If the two lids be forcibly drawn outwards this tendon can be readily felt and seen, and serves as a guide to the sac. It can also be felt as it,is tightened, when the lids are firmly closed. It crosses the sac at right angles> and at about the junction of its upper third with its lower two-thirds. A knife entered immediately below the tendon would about open the middle of the sac, and it may be noted that a lachrymal abscess, when about to discharge, always points THE HEAD AND NECK [Chap. below the tendon. Epiphora, or overflow of tears, is due in the main to two causes : (1) to an obstruc- tion in any part of the lachrymal passages from the puncta to the opening of the nasal duct in the Lac*. Gland Plica 5emilua4. /iASIOAl Canaliculus I/nt. Tarsal Lie. Lacn. 5ac UL/IasalDuct MP. riEATUS Fig. 19. — Diagram of the lachrymal apparatus. The arrow points to the first molar tooth, showing the direction of the nasal duct. nose; (2) to any cause that removes the lower punctum from its contact with the globe, as may be the case in ectropion, in entropion, in swelling of the lower lid, etc. Facial palsy causes epiphora, because, the orbicular muscle being relaxed, the punctum falls away from the globe, and, more- IVJ NASAL DUCT 81 over, the passage of the tears is no longer aided by the suction action effected by the muscle in the process of winking. The canaliculi may readily be slit up with a proper knife, and a probe can without difficulty be passed down the nasal duct from the lachrymal sac. The nasal duct is a little over i an inch in length, and the probe that traverses it should pass downwards, and a little backwards and outwards, in the direction of the first molar tooth (Fig. 19). The nasal duct perforates the mucous membrane of the nose below the inferior turbinate process very obliquely, so that its inner wall acts as a valve. If this is destroyed by ulceration, as sometimes oc- curs in syphilis, the lachrymal sac may be inflated by blowing the nose. The bony nasal duct has a calibre which varies from 25 to 7'5 mm. in dia- meter ; the thick mucous membrane which lines it has a rich venous plexus in its submucous layer which readily swells and prevents the passage of tears when the duct is inflamed. The normal duct will take a probe measuring 3*5 mm. in diameter ; it must be remembered that the lumen of the duct is normally closed, and that its lining membrane possesses several transverse folds which may catch the point of a probe. Inflammatory conditions readily ascend from the nasal cavity to the lachry- mal sac through the nasal duct. As affections of the lachrymal sac are often very painful, it may be noted that the nerve supply of the sac is derived from the infratrochlear branch of the nasal nerve. CHAPTER V THE EAR The pinna. — The pinna may be congenitally absent, or may be supplemented by supernumerary portions of the auricle, which may be situated upon the cheek or side of the neck. In the latter situation the so-called supernumerary auricle consists of an irregular leaf of fibro- cartilage developed from the margins of one of the lower branchial clefts. t (See p. 200.) The tag-like supernumerary auricles that are found on the cheek just in front of the pinna or meatus are due to the irregular development or want of fusion of one or more of the six tubercles from which the pinna itself is developed. The pinna may present a congenital fistula dependent on a defective closure of the first branchial cleft. The position of this cleft is represented in the normal ear by the Eustachian tube, the tympanum, and the external auditory meatus, the pinna being developed from the integument bordering the cleft. In these congenital fistulse, when well marked, the pinna is cleft above or below the meatus. Some of the smaller and more superficial fistulse are due not to a defective closure of the branchial cleft but to want of complete fusion between certain of the tubercles from which the pinna is primarily developed. Accidental removal of the pinna is usually associated with but comparatively little diminution in the acuteness of hearing. The skin covering the auricle is thin and closely 82 Chap. V] EXTERNAL AUDITORY MEATUS 83 adherent. The subcutaneous tissue is scanty, and contains but very little fat. In inflammatory con- ditions of the surface, such as erysipelas, the pinna may become extremely swollen and very great pain be produced from the tenseness of the parts. The pinna and cartilaginous meatus are very firmly attached to the skull, so that the body, if not of great weight, may be lifted from the ground by the ears. The external auditory meatus is about lj inches long. It is important to remember that the meatus is directed forwards as well as inwards ; to reach and expose the middle ear the surgeon takes the posterior wall of the meatus as a guide. The external meatus, the promontory, the cochlea, and the internal meatus lie nearly in the same line. The canal has a vertical curve about its middle, with the convexity upwards. To straighten the canal for the introduction of specula and other in- struments, the pinna should be drawn upwards and a little outwards and backwards. The osseous part forms a little more than one-half of the tube, and is narrower than the cartilaginous part. In the infant at 1 year, a third only of the meatus is formed of bone. The rest is cartilagin- ous. In a child 5 or 6 years of age the bony and cartilaginous portions of the meatus are about of the same length (Symington). The meatus is relatively as long in a child as it is in an adult. The narrowest portion of the meatus is about its middle. The outer orifice is elliptical, with its greatest diameter directed from above downwards; therefore specula should be elliptical in shape rather than round. The inner end of the tube, on the other hand, is slightly wider in the transverse direction. Owing to the obliquity of the mem- brana tympani, the floor of the meatus is longer than the roof. The cartilaginous segment of the tube presents many sebaceous glands that may be the seat of minute and very painful abscesses. It also presents numerous ceruminous glands, which secrete the cerumen of the ear, and which, when 84 THE HEAD AND NECK [Chap. their secretion is excessive, may produce the plugs of wax that often block the meatus and cause deaf- ness. In the cartilage of the floor of the meatus are certain fissures, fissures of Santorini. They are filled up with fibrous tissue. They permit of easier movement of the cartilaginous meatus. It is through these gaps in the cartilage that a parotid abscess may burst into the meatus. There are neither hairs nor glands in the lining of the bony part of the tube. The skin of the meatus, when inflamed, may pro- duce an extensive muco-purulent discharge, otitis externa. Polypi are apt to grow from the soft parts of the canal, and exostoses from its bony wall. Foreign bodies are frequently lodged in the meatus, and often involve great difficulties in their extraction. It would appear that in many cases more damage is done by the surgeon than by the intruding substance. Mason reports three cases where a piece of slate-pencil, a cherry-stone, and a piece of cedar-wood were lodged in the canal for respectively forty years, sixty years, and thirty years. The upper wall of the meatus is in relation with the cranial cavity, from which it is only separated by a dense layer of bone. Thus, abscess or bone dis- ease in this part may possibly lead to meningitis. A case is reported where an inflammation of the cerebral membrane followed upon the retention of a bean within the meatus. The anterior wall of the canal is in relation with the temporo- maxillary joint and with part of the parotid gland. This may serve in one way to explain the pain often felt in moving the jaw when the meatus is inflamed, although, at the same time, it must be remembered that movement of the lower maxilla produces a movement in the cartilagin- ous meatus, and that both the canal and the joint are supplied by the same nerve (the auriculo- temporal). From its relation to the condyle of the jaw, it follows that this wall of the^meatus has been fractured by that condyle in falls upon the V] THE EAR 85 chin. Tillaux states that abscess in the parotid gland may spread into the meatus through the anterior wall of the passage. The posterior wall separates the meatus from the mastoid cells. Directly behind the posterior wall, at a distance of 12 or 15 mm., is the lateral sinus (Fig. 22). The inferior wall of the bony meatus is very dense and substantial, and corresponds to the vaginal and styloid processes. Blood supply. — The pinna and external meatus are well supplied with blood by the tem- poral and posterior auricular arteries, the meatus receiving also a branch from the internal maxillary. In spite of this supply, the pinna is frequently the seat of gangrene from frost-bite. This is due to the fact that all the vessels are superficial and lie close beneath the surface, that the part is much exposed to cold, and that the pinna lacks the pro- tection of a covering of fat. The same conditions predispose to gangrene of the nose from external cold. Bloody tumours (hsematomata) are often met with on the pinna, and are common in boxers, foot- ball players, and lunatics. They are due to injury, and consist of an extravasation between the perichondrium and the cartilage. IVerve supply. — The pinna is supplied by the auriculotemporal, great auricular, and small occipital nerves {see Fig. 4, p. 15). Arnold's nerve, the auricular branch of the vagus, sends a twig to the back of the concha, near the mastoid process. The meatus is supplied mainly by the auriculo- temporal, with, in addition, a contribution from Arnold's nerve, which goes to the lower and back part of the canal, not far from its commencement. Arnold's nerve has been credited with a good deal in connexion with the nerve relations of the ear. After a heavy dinner, when the rose-water comes round, it is common to see the more experienced of the diners touch the lower part of the back of the ear with the moistened serviette. This is said to be very refreshing, and is supposed to be an unconscious stimulation of Arnold's nerve, a nerve 86 THE HEAD AND NECK [Chap. whose main trunk goes to the stomach. Hence, this little branch has been facetiously termed "the alderman's nerve." Ear coughing, ear sneezing, ear yawning.— It is not uncommon to have a troublesome dry cough associated with some mischief in the meatus. Sometimes the mere introduction of a speculum will make the patient cough. A case is reported in which a troublesome cough persisted for eighteen months, and at once ceased on the re- moval of a plug of wax from the ear. In such cases the irritation is conveyed to the respiratory and cough centres in the floor of the fourth ventricle by Arnold's nerve, a small branch of the vagus. Gas- kell has shown that the vagus also contains the dis- associated visceral fibres of the fifth nerve. Hence, disturbances may be set up in the vagal nuclei through branches of the fifth nerve, such as the auriculo-temporal. The connexion of the nerves of the external auditory meatus with the vagal nuclei also explains the sneezing or vomiting which is sometimes caused by the presence of foreign bodies in the external meatus. The same nerve- connexion also- explains the occurrence of repeated yawning, sometimes set up by ear ailments. Irrita- tion conveyed along the inferior dental or lingual nerves may be referred along the auriculo-tem- poral. Hence the need to examine the tongue and lower teeth in cases of earache. Head has pointed out that disease of the ear, the^ tonsil, the tongue, or the lower jaw may be associated with an area of tenderness in the skin along and below the jaw. It is a common practice to introduce ear-rings with the idea of relieving obstinate affections of the eye. No anatomical basis can be offered to explain such treatment. The lobule is supplied by the great auricular nerve which springs from the second and third cervical nerves, while the eye is supplied by the ophthalmic division of the fifth. The lower sensory nucleus of the fifth is a direct continuation upwards of the grey matter from which the pos- terior roots of the cervical nerves arise. V] MEMBEANA TYMPANI 87 Hilton reports a case of obscure pain in the ear which was found to be due to an enlarged gland in the neck, that pressed upon the trunk of the great auricular nerve. Membrana tympani.— This membrane is very obliquely placed, forming with the horizontal an angle of 45°. At birth it appears to be more nearly Fig. 20. — Section through the external meatus, middle ear, and Eustachian tube. {Tillaux.) a, External auditory meatus ; b, attic of tympanum ; c, Eustachian tube ; d, internal auditory meatus ; e, cochlea ;/, ossicles ; g, mem- brana tympani : h, styloid process. horizontal, although it is not really so. In cretins, and in some idiots, it is said to retain this apparent inclination. Owing to the sloping downwards of the bony wall of the meatus at its inner end, that wall forms with the lower edge of the membrane 88 THE HEAD AND NECK [Chap. a kind of sinus in which small foreign bodies may readily lodge (Fig. 20). The ring of bone to which the membrane is attached is deficient at its upper and anterior part. The gap so formed is called the notch of Rivini, and is occupied by loose connective tissue, covered by a continuation of the lining of the meatus, and through it pus may escape from the middle ear into the auditory canal without perforating the membrane. When the membrane gives way owing to a violent concussion transmitted through the air, it often gives way opposite the notch, its attachments here being ob- viously less secure than elsewhere. The membrane possesses but little elasticity, as shown by the very slight gaping of the part after it has been wounded. It is for this reason, among others, that perfora- tions made in the membrane by the surgeon heal so very rapidly. The membrane has been ruptured during fits of sneezing, coughing, vomiting, etc. The same lesion has followed a box on the ear, and even simple concussions such as that produced by a loud report. The umbo, or deepest point of the depression in the diaphragm, is just below the centre of the en- tire membrane, and corresponds to the attachment of the end of the handle of the malleus. The rest of the handle can be seen through the membrane dur- ing life. The head of the malleus is in no con- nexion with the membrane, being situated in the attic of the tympanum above the level of the mem- brane (Fig. 20). The segment of the membrane above the umbo is very freely supplied by vessels and nerves ; it corresponds to the handle of the malleus, and to the chain of ossicles, and is opposite to the promontory and the two fenestras. The chorda tympani nerve also runs across this supraumbilical portion. The segment below the umbo, on the other hand, corresponds to no very important parts, and is less vascular and less sen- sitive. Paracentesis of the tympanum through the membrana tympani should therefore always be per- formed in the subumbilical segment. If performed V] THE TYMPANUM 89 above the umbo the knife may strike the incus and loosen that bone from its frail attachments, or the chorda tympani may be cut, which would give rise to a paralytic secretion of saliva. The malleus and stapes are too firmly attached to be readily detached. The membrane is supplied by the stylo-mastoid artery and the tympanic branch of the internal Antrum ,Ext. Semicirc. Canal ,VH»MeR*E Aditus Fenestra Ovaus Tec me/s TyAtPANi Processus Cocm. 3«-52^ , MOnroRy ^>^ ( PYRAMID \^\ \, Fenestra Rotunda i \ \ vIastoid Cells Mastoid Process Fig. 21. — Inner wall of tympanum and antrum. The position of the external semicircular canal and course of the facial nerve (vii.) are shown. maxillary, and obtains its nerve supply from the auriculo-temporal and vagus. The tympanum.— The width of the tympanic cavity, as measured from its inner to its outer wall, varies from 2 to 4 mm., ^Wth to Jth of an inch. The narrowest part is that "between the umbo of the membrana and the promontory. A fine rod thrust through the centre of the membrana tympani would hit the promontory of the inner wall of the cavity. Above the promontory is the fenestra ovalis, and below and behind it the fenestra rotunda (Fig. 21). 90 THE HEAD AND NECK [Chap. Skirting the upper and posterior margin of the inner wall of the tympanum is the aqueduct of Fallopius, containing the facial nerve. The wall of the aqueduct is so thin that inflammatory mischief can readily extend from the middle ear to the facial nerve. The upper wall is very thin, and but little bone separates it from the cranial cavity. The suture between the squamous and petrous bones is found in this wall, and by means of the sutural Fig. 22. — Showing the r position and relationships of the various parts of the middle ear. (See also Fig. 3, p. 12.) membrane that separates the bones in the young, inflammatory changes may readily spread from the tympanum to the meninges. The petro-squamous suture unites at the end of the first year and usually contains the petro-squamous vein, a remnant of the primitive jugular. The floor is very narrow. Its lowest part is below the level of both the mem- brana tympani and the orifice of the Eustachian tube, and hence pus may readily collect in this locality (Fig. 21). It is separated by a thin piece V] MASTOID ANTRUM 91 of bone from the internal jugular vein behind, and from the internal carotid artery in front. Fatal haemorrhage from the latter vessel has occurred in connexion with destructive changes in this part of the ear. The posterior wall in its upper part pre- sents the opening or aditus of the antrum of the mastoid. The antrum opens into the attic — that part of the tympanic cavity which is situated above the level of the membrana tympani (Fig. 22). The antrum of the mastoid (Figs. 20, 22) lies above and behind the external auditory meatus. Implication of this space and of the mas- toidal cells, which open into it and surround it, forms one of the most serious complications of middle-ear disease. It is large enough to contain a small bean, and is present at birth (Fig. 23), being developed with the cavity of the tympanum. It is closely surrounded by important structures. Its roof, formed by the tegmen tympani, a plate of bone only 2 mm. thick, separates it from the third temporal convolution. Small veins perforate the roof to join the petro-squamous vein, in the rem- nant of the suture of the same name. In the infant the communication is even more free, for this suture does not close until the end of the first year. The facial nerve passes downwards on its inner wall, where the antrum opens into the attic, and behind the facial nerve, also on the inner wall, is the external semicircular canal (Fig. 21). Facial paralysis or giddiness may follow operations on the antrum if the inner wall is injured. The superior and posterior borders of the meatus indicate the position of the facial nerve (Fig. 22) ; on the inner wall of the antrum, the nerve is situated 14 to 22 mm. deep to the suprameatal triangle (Joyce). The antrum is separated from the lateral sinus and cerebellum behind by a plate of bone which varies in thickness from 3 mm. to 6 mm. The temporo-sphenoidal lobe, the lateral sinus, and the cerebellum are the common seats of secondary infection in cases of middle-ear disease. At the mouth of the antrum and in the attic of the 92 THE HEAD AND NECK [Chap. tympanum are situated the incus, the head of the malleus, and their ligaments, structures which may be diseased and require removal. At birth the outer wall of the antrum is formed by the postmeatal process of the squamosal, a plate of bone 2 mm. thick (Fig. 23). In the child the antrum is comparatively superficial, and pus may easily escape or be evacuated. The suture between the postmeatal part of the squamosal and the petro-mastoid disappears in the second year of life, Squamosal Aaitrum Attic POST.I/MF. FONTANELLE A/IT. IMP. fO/iTAAiELLE Squano /Iasto Suture /Iastoid^ " 'TyM PA/SIC RlrtQ Drum Stylomastoid Foramen Fig. 23. — Temporal bone at birth. The position of the antrum and attic is indicated. The squamo- mastoid suture is open and the mastoid process undeveloped. and so shuts off a possible route that pus may take to reach the surface (Fig. 23). The outer wall of the antrum steadily increases in thickness until adult life, when the depth of the cavity from the surface of the bone is found to vary in different in- dividuals from 12 to 22 mm., about 16 mm. being its average depth. A shallow triangle (see Fig. 22) above and behind the meatus lies directly over the antrum and serves as a guide to its position. It may also be reached by following the junction of the posterior wall and roof of the external auditory V] MASTOID CELLS 93 meatus. The drill is entered 5 mm. behind the meatus and on a level with its upper margin. Its roof lies 5 mm. above the level of the meatus. The posterior auricular artery passes upwards behind the meatus, beneath the concha of the auricle, and lies within the field of any operation on the middle ear. The mastoid cells develop with the growth of the mastoid process, which appears as a definitely marked structure in the second year. Besides the antrum there are also some cells present in the outer wall at birth (Young). During infancy there are two types of mastoid : one in which the bone is dense — a form which persists in 1 per cent, of adults; and one in which the mastoid is diploetic — a form which is retained in 20 per cent, of adults (A. Cheatle). Three varieties of the mastoid process are recognized in adults, each of which is about equally com- mon : (1) those in which the cells are large and communicate with each other and with the antrum, (2) those in which the central cells are large and communicate with the antrum, while the peripheral are small and closed, (3) those in which all the spaces are small and closed. The cells surround the antrum, and may pass backwards to the masto- occipital suture, forwards to the suprameatal region, upwards to the masto-parietal suture, and downwards to the apex of the mastoid. Inflamma- tory conditions may lead to a thickening of the walls of the mastoidal cells, and the bone may be- come so dense as almost to resist the chisel. Veins drain into the periosteum of the mastoid from the more superficial cells, and by these inflammation may reach the surface and give rise to oedema and swelling behind the ear. In cases where the outer surface of the mastoid has been spontaneously perforated, a tumour, containing air, has appeared on the skull, and it has been ^ observed that the tumour may be increased in size by forcing air into the ear through the Eustachian tube. Such tumours are 94 THE HEAD AND NECK [Chap. known as pneumatoceles, and the process that leads originally to the perforation of the bone is of obscure nature. In some cases it seems to have been simply atrophic, and in other instances to have been due to " caries sicca." On the anterior wall of the tympanum is the opening of the Eustachian tube (Figs. 20 and 21). This tube is If inches long, and by opening into the pharynx serves to keep a proper supply of air in the tympanum, and so equalize the pressure upon the two sides of the membrane. The floor of the tympanum is below the level of the outer opening of the Eustachian tube. The line of direction of the tube lies almost exactly midway between the trans- verse and antero-posterior axes of the base of the skull. In the adult it inclines downwards, so as to form an angle of 40° with the horizontal. In the child this angle is only 10° (Symington). In adults jths of the tube is cartilaginous and ith bony (Symington). On the outer side of the tube lie the tensor palati, the third division of the fifth nerve, and the middle meningeal artery. On the inner side are the retropharyngeal tissue and (quite pos- teriorly) the internal carotid artery. The pharyn- geal orifice of the tube is usually shut. During swallowing, however, it is opened by the action mainly of the tensor palati muscle. If the nose and mouth be closed and the cheeks blown out, a sense of pressure is produced in both ears. The hearing, at the same time, is dulled, and the change is due to the bulging out of the membrana tympani by the air thus forced into the tympanum. This method of inflating the middle ear is known as Valsalva's method. In Politzer's method of passing air into the Eustachian tube, the patient's mouth is closed, while into one nostril the nozzle of a caoutchouc bag filled with air is introduced, and the nostrils are then held firmly closed. The patient is asked to swallow a mouthful of water, while at the same moment the bag is forcibly emptied, and the air, having no other means for escape, is thus driven V] EUSTACHIAN TUBE 95 into the open Eustachian tube. The surgeon listens for the little noise caused by the entrance of the air by means of a tube that passes between the patient's meatus and his own. Prolonged closure of the Eustachian tube leads to deafness, and thus impairment of hearing may follow upon great thickening of the mucous membrane of the tube due to the extension of inflammatory mischief from the pharynx. In the deafness associated with enlarged tonsils and postnasal growths, the hypertrophic change extends to the mucous lining of the tube, and in the cases of many pharyngeal growths and nasal polypi, the orifice of the tube is mechanically obstructed. The near relation of the pharyngeal end of the tube to the posterior nares serves to explain a case where suppuration in the mastoid cells followed upon plugging of the nares for epistaxis. Infection may be carried up to the middle ear by means of the ciliated lining of the Eustachian tube ; C. J. Bond found that indigo particles, which had been blown within the naso- pharynx, in a case of perforation of the drum, ap- peared afterwards in a discharge from the external meatus. The upper edge of the pharyngeal orifice of the tube is about \ an inch below the basilar process, i an inch in front of the posterior wall of the pharynx, \ an inch behind the posterior end of the inferior turbinate bone, and h an inch above the soft palate (Tillaux). In the foetus the orifice is below the hard palate; at birth, on the same, level. The form of the opening is that of a triangle. The opening of the tube is effected by the tensor palati, levator palati, and salpingo- pharyngeus. Just behind the elevation formed at the orifice of the Eustachian tube there is a depression in the wall of the pharynx, the lateral recess or fossa of Rosenmiiller (Fig. 25, p. 106). It may be mis- taken for the orifice of the tube, and may readily engage the point of a Eustachian catheter. In cases in which the pharyngeal tonsil (Luschka's 96 THE HEAD AND NECK [Chap. tonsil) is enlarged, this fossa on either side may be greatly deepened and made to form a narrow diverticulum. (See p. 159.) To pass the Eus- tachian catheter, the instrument is carried along the floor of the nares with its concavity down- wards, " until its point can be felt to drop over the posterior edge of the hard palate into the pharynx. The instrument should now be with- drawn until its point can be felt to rise again on the posterior edge of the hard palate ; having arrived at this point, the catheter should be pushed onwards about 1 inch, and during its passage its point should be rotated outwards through a quarter of a circle. ?; This manoeuvre should engage it on the orifice of the tube. Blood supply.— The tympanum is supplied by the following arteries : The tympanic of the in- ternal maxillary and internal carotid, the petro- sal of the middle meningeal, and the stylo-mastoid of the posterior auricular. The fact that some of the tympanic veins end in the superior petrosal and lateral sinuses gives another explanation of the frequent occurrence of thromboses of those channels in inflammatory affections of the middle ear. The petro-squamous vein, which crosses the roof of the middle ear, also receives branches from the antrum and attic and joins the lateral sinus behind and the meningeal veins in front (Cheatle). The lymphatics of the middle ear follow two routes. The majority pass along the wall of the Eustachian tube and end in the retropharyngeal lymphatic gland. Others reach the postauricular group of glands, situated over the mastoid process, by passing out beneath the lining membrane of the meatus and by other efferent channels which accompany the veins escaping by the superficial openings that are seen on the mastoid part of the temporal. The chorda tympani nerve, from its exposed position in the tympanum, is very likely to be damaged in suppurative disease of the middle VJ OSSEOUS LABYRINTH 97 ear ; and it has been shown that, when this nerve is involved, there may be a disturbance in the sense of taste, which is easily understood when one remembers that some of the nerves of taste reach the tongue by this route. The osseous labyrinth is formed independ- ently of the other bony parts of the ear. Portions of this labyrinth have necrosed and have been expelled in recognizable fragments. In a case recorded by Dr. Barr the whole of the osseous labyrinth (the cochlea, vestibule, and semicircular canals) was removed entire as a necrosed frag- ment from the auditory meatus. Suppuration of the middle ear may spread to the inner ear, either through the fenestra ovalis, in which the foot- plate of the stapes is fixed by the strong annular membrane, or by the fenestra rotunda, which is closed by the membrana secundaria. From the inner ear the suppurative process may extend in- wards along the auditory nerve and meatus, thus reaching the large subarachnoid spaces at the base of the brain. Middle-ear disease may lead to the formation of a fistulous opening in the external semicircular canal. In such cases movements of the head may give rise to nystagmus, for reflex movements of the eyes are influenced by stimuli which arise in the maculse of the semicircular canals (Sydney Scott). CHAPTER VI THE NOSE AND NASAL CAVITIES The Nose The skin over the root, and the greater part of the dorsum, of the nose is thin and lax. Over the alse, however, it is thick, very adherent to the deeper parts, and plentifully supplied with sebaceous and sweat glands. Inflamma- tion of the integuments over the cartilaginous portion of the nose is apt to be very painful, and to be associated with much vascular engorge- ment. The pain depends upon the tenseness of the part, which prevents it from swelling without pro- ducing much pressure upon the nerves, while the engorgement depends upon the free blood supply of the region, and the fact that the edge of the nostril being a free border, the circulation there is terminal, and apt therefore to favour con- gestion. The great number of sebaceous glands about the lower part of the nose renders it a favourite spot for acne. It is here that the form of acne termed acne hypertrophica is met with — a con- dition that produces the appearance known as 44 grog blossoms." The nose,^ too, is frequently attacked by lupus, and it is over the dorsum of the nose that lupus erythematosus is most commonly met with. ^ Rodent ulcer also is apt to appear in this region, especially in the fold between the ala of the nose and the cheek, 98 Chap. VI] THE NOSE 99 The integument of the nose is very well sup- plied with blood, and for this reason the part is well suited for the many plastic operations that are performed upon it. Wounds in this region heal kindly, and even the extensive wound made along the line between the nose and the cheek in removal of the upper jaw leaves very little de- formity. In many reported cases portions of the nose have been entirely severed, and have united to the face on being immediately re-applied. t The skin over the root of the nose is supplied by the nasal branch of the first division of the fifth; as is also the skin over the alae and in the region of the nostril (Fig. 4, # p. 15). ^ The greater part of the side of the nose is supplied by the second division of the fifth, and is the seat of pain in neuralgia of that trunk. The fact that the nasal nerve is a branch of the ophthalmic trunk, and has intimate connexions with the eye, serves to explain the lachrymation that often follows painful affections about the nostril, as, for example, when the edge of the nostril is pinched. The cartilaginous part of the nose is often destroyed by lupus, by syphilitic ulceration, and other destructive affections. The parts so lost have been replaced by the various methods in- cluded under the head of rhinoplasty. It is well to bear in mind the limits of the cartilaginous segment of the nose, and to remember that in in- troducing a dilating speculum the instrument should not be passed beyond those limits. In the subjects of inherited syphilis the bridge of the nose is often found to be greatly depressed. This depends upon no actual loss of parts, but rather upon imperfect development f rom ^ local mal- nutrition, that malnutrition following upon a severe catarrh of the mucous membrane. The de- formity only occurs, therefore, in those who have had " snuffles " in infancy. The nasal bones , are, often, .broken Jby direqt violence. The fracta^e" itf most common through 100 THE HEAD AND NECK [Chap. the lower third of the bones, where they are thin- nest and least supported. It is rarest in the upper third, where the bones are thick and firmly held 5> and where, indeed, considerable force is required to produce a fracture. Since no muscles act upon the ossa nasi, any displacement that occurs is due solely to the direction of the force. Union takes place after these fractures with greater rapidity than perhaps obtains after frac- ture of any other bone in the body. In one case noted by i Hamilton, " the fragments were quite firmly united on the seventh day." If the mucous membrane of the nose be torn, these fractures are apt to be associated with emphysema of the sub- cutaneous tissue, which is greatly increased on blowing the nose. The air in such cases is de- rived, of course, from the nasal fossse. In frac- tures of the upper third of the ossa nasi the cribriform plate may be broken, but it is ques- tionable whether this complication can occur when the fracture is limited to the lower third of the bones. The root of the nose is a favourite place for meningoceles and encephaloceles, the protrusion escaping through the suture between the nasal and frontal bones. Such protrusions, when occurring in this place, are often covered with a thin and vascular integument, and have been mistaken for nsevoid growths. The Nasal Cavities The anterior nares have somewhat the shape of the heart on a playing-card, and the aperture as a whole measures about lj inches vertically, and a little less than \\ inches trans- versely, at its widest part. The plane of the nostril is a little below that of the floor of the nares. To examine the nasal cavities, there- fore, the head should be thrown back and the nose drawn upwards. The anterior nares can be well explored by the finger introduced into the nostril, and the r>asaj apertures. are just so wide on'. each side of the septum "an id allow the finger .VI] THE NARES 101 to be passed far enough back to reach another finger introduced into the posterior nares through the mouth. An effectual way of removing soft polypi in the adult is by tearing them away by two fingers so introduced. The operation is a little rough. By the most gentle introduction of the finger into the nostril it is often possible to feel the end of the inferior turbinated bone. The anterior nares, and front of the nasal cavities, can be well explored by Rouge's operation. In this procedure the upper lip is everted, and a transverse cut made through the mucous mem- brane into the soft parts that connect the upper lip with the upper jaw. The incision extends be- tween the second bicuspid teeth of either side. The soft parts connecting the upper lip and nose to the bone are divided without damaging the skin, and the flap is dissected up until the nares are sufficiently exposed. Posterior nares.— If a little mirror, some- what similar to that used in laryngoscopy, be cautiously introduced behind the soft palate through the mouth, and illumined from the mouth, the following parts may, in favourable circum- stances, be seen, viz. the posterior nares, the septum, the middle turbinated bone, part of the superior and inferior turbinated bones, and part of the inferior meatus. The middle meatus is well seen, and also the Eustachian tube, and the mucous membrane of the upper part of the pharynx. This mode of examination is very difficult to carry out, and is known as posterior rhinoscopy. The parts just named can all be felt by the finger introduced behind the soft palate through the mouth. The posterior nares are often plugged to arrest severe bleeding from the nose, and in order to cut a proper-sized plug it is desirable to bear in mind the dimensions of the apertures. Each aperture is of regular shape, and measures about i an inch transversely by l\ inches in the vertical direction in a well-developed adult skull. 102 THE HEAD AND NECK [Chap. As regards the nasal cavities generally, it is well to note that the floor is wider at the centre than at either end, that the vertical diameter is greater than the transverse, and is also greatest about the centre of the fossae. Forceps introduced into the nose, therefore, are most conveniently opened if opened vertically. The width of the fossae increases somewhat from above downwards ; thus the superior turbinated bone is only 2 mm. from the septum, while a space of from 4 to Fig. 24. — Transverse vertical section of the nasal cavities and accessory sinuses. 5 mm. intervenes between the inferior turbinated bone and the septum. The nasal cavity is so very narrow above the middle turbinated bone that that bone really forms the surgical roof of the nasal fossae. The shape and proportions of the nasal cavity in the child are peculiar. In the adult the inferior meatus is large (Fig. 24), and con- stitutes the chief respiratory passage ; in the young child the inferior meatus is relatively very small, the middle meatus affording the main space for the VI] NASAL CAVITIES 103 respiratory tide (Lack). The nasal cavities grow rapidly from the sixth to the eighteenth year ; during this period the permanent dentition is be- ing formed, necessarily causing an increase in the size of the palate and of the floor of the nose ; at the same time the development of the antrum of the maxilla leads to an increase in the vertical height of the nose, this increase affecting the lower or maxillary much more than the ethmoidal or olfac- tory part of the cavity. Growth of the nasal cavities and of the face may be arrested or viti- ated by any obstruction to the free passage of the breath through the nose ; the most common cause of obstruction is the formation of adenoids in the naso-pharynx. By referring to the relations of the nasal fossse (Figs. 24, 25) it will be understood that inflam- mation of the lining membrane (coryza) may ex- tend to the pharynx via the posterior nares ; may extend up the Eustachian tube and cause some deafness; may reach the lachrymal sac and con- junctiva through the nasal duct; and may extend to the frontal sinuses and the antrum, producing frontal headache and cheekache. These relation- ships are often demonstrated in a severe " cold in the head." From the nearness of the nasal fossse to the cranial cavity it happens that menin- gitis has followed upon purulent inflammations of the nose. Foreign bodies of various kinds are often lodged in the nose, and may remain there for some years. Thus, Tillaux reports the case of an old woman aged 64, from whose nose he removed a cherry-stone that had been there for twenty years. In washing out the nasal cavities with the " nasal douche " the fluid is introduced by means of a siphon. The nozzle of the siphon tube is introduced into one nostril, the mouth is kept open, and the fluid runs through that nostril, passes over the soft palate, and escapes from the other nostril. The latter cavity is therefore washed out from behind forwards. The course of 104 THE HEAD AND NECK LChap. the fluid depends upon the fact that when the mouth is kept open there is such a disposition to breathe through it alone that the soft palate is drawn up and the nares cut off from the pharynx. The root of each nasal fossa is very narrow, being only about J of an inch in width (Fig. 24). It is mainly formed by the thin cribriform plate, but its width is such that the danger of the roof being penetrated by so large a substance as a pair of polyp forceps has been greatly exaggerated. The cranial cavity has, however, been opened up through the roof of the nose by penetrating bodies introduced both by accident and with homicidal intent. Meningitis has followed inflammation of the nasal fossse, the inflammation extending through the cribriform plate. Through the peri- neural and perivascular sheaths the lymphatic system of the nose is in continuity with that of the meninges, and by these channels infections may spread from the roof of the nose to the mem- branes of the brain. Fracture of this part also has been associated with very copious escape of cerebro-spinal fluid through the nostrils. A men- ingocele may protrude through the nasal roof. Tn a case reported by Lichtenberg the mass hung from the mouth, having passed through a congeni- tal fissure in the palate. It was mistaken for a polyp, was ligatured, and death resulted from intracranial inflammation. The septum is seldom quite straight in adults; the deviation being more often towards the left. . It is, however, straight in children, and remains so up to the seventh year. In adults the septuin deviates in 76 per cent, of all persons. The deviation may follow an injury. It has been pointed out that a deviation of the septum may seriously interfere with the singing voice. The nose also is seldom quite straight, and French authors ascribe this to some deviation of the sep- tum, often dependent upon the practice of always blowing the nose with the same hand. If the deviation of the septum be considerable, it may VII NASAL OUTER WALL 105 more or less block one nostril, and, until the oppo- site nostril is examined, be mistaken for a septal tumour encroaching upon the cavity. The flat- tened nose in acquired syphilis is usually due to destruction of the septum and more or less implication of the adjacent bones. Outer wall (Fig. 25). — The inferior turbin- ated bone may interfere with the introduction of a Eustachian catheter if the curve of the instru- ment be too great. The anterior end of the bone is about | of an inch behind the orifice of the nostril. The opening of the nasal duct is about 1 inch behind the orifice of the nostril, and about | of an inch above the nasal floor. This opening is usually slit-like and narrow. The nasal duct pierces the nasal mucous membrane in the same oblique and valvular manner as the ureter enters the bladder. The height of the inferior meatus is about | of an inch. The superior meatus is a very short and narrow fissure, and into its upper and fore part open the posterior ethmoidal cells. The middle meatus opens widely in front upon a part of the outer wall called the atrium, and unless care be taken to keep the point of any in- strument well towards the floor of the fossa, it is easier to pass the instrument into the middle than into the inferior meatus. Upon the wall of the middle meatus is a deep gutter (the hiatus semilunaris), which runs from above downwards and backwards (Fig. 25). Into this groove open the infundibulum (the aperture of the frontal sinus)^ the anterior ethmoidal cells, and, near its posterior end, the antrum. The rounded aperture of the frontal sinus is usually situated in the anterior end of the hiatus, but not infrequently it will be found in a recess above and in front of the hiatus. The anterior ethmoidal cells, usually two in number, may open into the hiatus, the infundibulum, or directly into the anterior part of the middle meatus. The opening of the antrum may occur below, instead of within, the posterior part of the hiatus semilunaris (Fig. 25). The E* 106 THE HEAD AND NECK [Chap. upper boundary of the hiatus is formed by the bulla ethmoidalis ; its lower sharp prominent margin contains the uncinate process of the eth- moid. The middle ethmoidal cell is seen to open on the bulla, above the hiatus semilunaris. The level of the hiatus within the nose may be indi- cated by the position of the internal tarsal liga- ment. The anterior end or beak of the middle Aey Fossa rtCMDAL Sl/^US P/IARVAICCALTOAiSIL I Lateral Recess j Eustachian Tube [ _\ EUSTACHIAN Cusnio/i 4- Atlas Soft Palate Fig. 25. — Outer wall of the nasal cavity. The greater part of the middle turbinate process has been cut away to expose the hiatus, bulla, and openings. A, B, indicate the two positions at which the opening of the antrum may occur. turbinate process can be seen distinctly from the anterior nares, when the interior of the nose is illuminated by reflected light. The width of the nasal floor is about J an inch, or a little over. Its smooth surface greatly favours the passage of instruments (Fig. 24). It presents a gentle slope from before backwards. At its anterior part is a depression of mucous membrane over the incisor foramen. This foramen VI] NASAL MUCOUS MEMBRANE 107 is a vestige of the great communication that once existed between the cavities of the nose and mouth. The mucous membrane lining the nasal cavi- ties is covered with ciliated epithelium over the lower two-thirds or respiratory part; the upper third — the olfactory part — is covered with colum- nar epithelium, while the vestibule is lined with stratified epithelium. It is very thick and vas- cular over the turbinate bones and over the lower two-thirds of the septum, while over the nasal floor and in the intervals between the turbinate bones it is very much thinner. The mucous membrane lining the various sinuses and the antrum is conspicuously thin and pale. The membrane is provided with many glands, which are most conspicuous over the lower and hinder parts of the outer wall and over the posterior and inferior parts of the septum. These glands may be the subject of considerable hypertrophy. They are capable of providing also a very copious watery secretion, which has in some cases of chronic coryza following injury been so free as to be mistaken for an escape of cerebro-spinal fluid. There is also much adenoid, or lymphoid tissue in the nasal mucous membrane, which is the primary seat of the chief scrofulous affec- tions that invade this part. So thick and lax is the normal mucous membrane over the lower border and posterior extremity of the inferior turbinated bones that it forms a kind of soft cushion, sometimes called the " turbinate body." This condition is mainly due to the presence of a rich submucous venous plexus, the vessels of which run, for the most part, in an antero-posterior direction. When turgid with blood it swells so as to obliterate the interval between the bone and the septum. When the seat of chronic inflam- mation, the mucous membrane over the inferior bone may appear as a polypoid swelling. Polypi are often met with in the nose. They are of two kinds, the mucous or myxomatous 108 THE HEAD AND NECK IChap. polyp that springs usually from the mucous mem- brane beneath or over the middle turbinate, and the fibrous or sarcomatous polyp that usually takes origin from the periosteum of the nasal roof or from that of the base of the skull. Polypi of the latter kind spread in every available direc- tion. They expand the bridge of the nose, close the nasal duct and cause epiphora, depress the hard palate and encroach upon the mouth, in- vade the antrum and expand the cheek, grow down into the pharynx, pushing forwards the velum palati, and may penetrate even through the inner wall of the orbit. Such tumours may be exposed and removed by separating the posterior and inner attachments of the superior maxilla, turning it forwards, thus exposing the nasal cavity by detaching its outer wall. The bone may be replaced in situ after removal of the tumour (F. S. Eve). The blood supply of the nasal cavity is extensive, and is derived from the internal maxillary, ophthalmic, and facial arteries. With regard to the veins, it may be noted that the ethmoidal veins that come from the nose enter the ophthalmic vein, while in children a constant com- munication exists between the nasal veins and the superior longitudinal sinus through the foramen caecum. This communication may also be main- tained in the adult. i These connexions may, in part, serve to explain the occurrence of intra- cranial mischief as a consequence of certain inflammatory affections of the nasal cavities. Bleeding from the nose, or epistaxis, is a common and often a serious circumstance. Its frequency is to a great extent due to the vascularity of the mucous membrane, to its laxity, and to the fact that the veins, especially those over the lowest turbinate bone, form extensive plexuses, and pro- duce a kind of cavernous tissue. The epistaxis is often due, therefore, to interference with the venous circulation, as seen in cases of cervical tumour pressing upon the great veins, in the VIJ NERVE SUPPLY OF NASAL CAVITY 109 paroxysms of whooping cough, and the like : The beneficial effect of raising the arms in epistaxis is supposed to depend upon the extra expansion of the thorax thus produced, and the aspiratory effect thus brought to bear upon the cervical veins. The bleeding may be copious and long continued. Thus, Spencer Watson reports a case where the epistaxis continued on and off for twenty months without obvious cause. Martineau mentions an instance in which 12 lb. of blood was lost in sixty hours, and Fraenkel records a case where 75 lb. of blood is said to have escaped from first to last. In several instances the haemorrhage has proved fatal. The seat of the bleeding is often not easy to detect, even when the examination is post-mortem. In many cases the bleeding point is situated on the septum, \ an inch above and behind the nasal spine. The nerve supply of these parts is derived from the olfactory nerve, and from the first and second divisions of the fifth nerve. The lachryma- tion that often follows the introduction of irri- tants into the front of the nares may be explained by the fact that that part of the cavity is sup- plied freely by the nasal nerve, a branch of the ophthalmic trunk. As an example of transfer- ence of nerve force in the opposite direction may be noted cases where a strong sunlight falling upon the eyes has produced an attack of sneez- ing. Troubles involving the vagal centres, such as cough and bronchial asthma, have followed affections of the nasal cavities. The olfactory nerves are situated in the upper third of the cavity, and thus, in smelling intently, the indi- vidual sniffs deeply and dilates the nostril. The inability to dilate the nostril in facial paralysis may explain the partial loss of smell sometimes noted in such cases. It is said (Althaus) that anosmia, or loss of the sense of smell, when fol- lowing upon an injury to the head, may be due to a rupture of the olfactory nerve fibres as they pass through the cribriform foramina. The olfactory 110 THE HEAD AND NECK [Chap. roots cross the edge of the lesser wings of the sphenoid, and in falls on the forehead are liable to injury. The olfactory centre is situated in the hippocampal gyrus. Most of the lymphatics of the nasal fossos enter the retropharyngeal glands placed behind the pharynx, in front of the rectus capitis anticus major. Hence, as Fraenkel has pointed out, " retropharyngeal abscess may arise in conse- quence of diseases of the nose." Other lympha- tics go to the submaxillary, parotid, and upper deep cervical lymph-glands, and it is common to find these enlarged in nose affections, especially in the scrofulous. The lymphatics of the nose also communicate with those of the meninges through the cribriform plate. Nasal sinuses. — Of late years a knowledge of the anatomy and relationships of the ac- cessory sinuses of the nose has become of the utmost importance to the surgeon. Over 15 per cent, of the subjects examined in the dissecting room of the London Hospital show disease of one or more of these sinuses; StClair Thomson, quot- ing from German statistics, estimates ^ that the sphenoidal sinus is the seat of disease in 30 per cent, of individuals— probably an overstatement. The collective capacity of the accessory sinuses — the maxillary, frontal, sphenoidal, and ethmoidal — is more than twice that of the nasal cavity (Braune). The frontal sinus is extremely variable in size and shape. The surface markings shown in Fig. 26 indicate the average development in the adult; the opening of its duct or infundibulum is shown in Fig. 25. Large frontal sinuses do not necessarily imply large external prominences over the glabella and superciliary eminences. One sinus may develop at the expense of the other, and the septum may be displaced. They are larger in men than in women. They are absent on one side in 9 per cent, of cases, and on both sides in 7 per cent. (Logan Turner). It VI] FRONTAL SINUS 111 is obvious that a depressed fracture may exist over a frontal sinus without the cranial cavity being damaged. In such cases the inspissated i Fro/ital Siaus AlASIOfl 1/iFU/NDlBULUM Lacai.Sac /*! id. Turbinate- /Iasal Duct Aaitrum l/IF- TURBIAI ATE- Fig. 26. — Surface markings of the frontal and maxillary sinuses. A, li " above nasion ; B, on the supra-orbital margin, at the junction of the middle and outer thirds ; C, on the infra-orbital margin to the outer side of the lachrymal sac ; D,on the centre of the cheek bone in line with the outer margin of the orbit ; E, over the second bicuspid ; F, over the last molar. The points A, B, and Nasion give the surface position of the frontal sinus ; c, D, E, F, that of the maxillary sinus. contents of the sinus have been mistaken for brain matter escaping. Since the sinuses are in communication with the nose, much emphysema may follow upon the fracture of the sinus wall. 1V2 THE HEAT) AND NECK [Chap. Insects have found their way into these cavities. " Centipedes are particularly liable to be found in tne frontal sinuses, where they may remain for years, the secretions of these cavities furnishing them with sufficient nourishment " (Fraenkel). Larvae have also been found here, and maggots that have developed within the nose have managed to make their way to the frontal sinuses. The frontal sinus is absent in early childhood. About the sixth year a bud of mucous membrane grows out from the anterior end of the hiatus, and gradually insinuates its growing extremity into the diploe of the frontal bone, separating the inner from the outer osseous table. It reaches its full size about the twenty-fifth year; the stalk of the outgrowth becomes the infundibulum; it leads from the posterior part of the sinus. The infundi- bulum is | of an inch long, and runs downwards and slightly backwards to open at or near the anterior end of the hiatus semilunaris. Along the hiatus the secretion of the frontal sinus may be conveyed to the antrum, thus converting that cavity into a cesspool in cases of chronic suppura- tion of the frontal sinus (Fig. 25). The infundi- bulum is frequently tortuous, and even after the beak of the middle turbinate process is removed it is not easy to catheterize from below. Hence in cases of obstruction the frontal sinus is trephined over the glabella, or at the superior internal angle of the orbit (Tilley), and a probe passed down- wards and slightly backwards to drain the sinus into the nose. The anterior ethmoidal cells commonly open into the^ infundibulum, and hence they are usually involved in any disease affecting the frontal sinus. The frontal diploic vein, which joins the frontal vein at the supra-orbital notch, receives blood from the frontal sinus. In cases of frontal suppuration, infection may spread rapidly in the frontal bone by means of the veins of the diploe, setting up a destructive form of osteitis and meningitis. VI] SPHENOIDAL SINUS 113 The sphenoidal sinus opens on the roof of the nose behind the superior meatus; it is de- veloped at the same period of life as the frontal sinus (.Fig. 25). It is deeply placed, and not very accessible for operation when the seat of disease. It is frequently the seat of chronic suppuration set up by infections from the nose. Its anterior wall, which is comparatively thin, is situated be- tween 7 and 8 cm. from the lower margin of the anterior nares. Tilley recommends the mid point of the lower border of the middle turbinate as a guide to the opening of the sphenoidal sinus. The nasal septum also serves as a safe guide, for its vomerine part is implanted on the anterior wall of the sinuses. A probe passed to this point from the floor of the anterior nares will, if passed straight onwards, reach the opening of the sinus at the depth mentioned above — 7 to 8 cm. In close contact with the thin lateral wall of this sinus there are certain extremely important struc- tures. Besides the cavernous sinus and internal carotid artery, the optic nerve and second division of the fifth nerve are in the closest contact, and may be affected in sinusitis (Fig. 30). On the roof is the pituitary body ; tumours of this body may invade the sinus. Its veins join the ethmoidal. The walls of the sinuses are thin and easily perforated, as the following case, which occurred at the London Hospital, will show. A man stumbled forwards on his umbrella as he left a public-house in Whitechapel, the point entering his face above the bicuspid teeth. He walked to the hospital, and died three days after- wards. The ferrule of the umbrella was found embedded in the pons, the point having traversed the antrum of Highmore and the sphenoidal sinus. The antrum exists at birth, but attains its largest dimensions in old age. The surface mark- ings for indicating its position on the face are given in Fig. 26. The walls of the cavity are 114 THE HEAD AND NECK [Chap. thicker in children than in adults. Tumours of various kinds are apt to develop in this cavity, and to distend its walls in various directions. Thus the growth breaks through the thin inner wall and invades the nose, it pushes up the roof of the cavity and invades the orbit, it encroaches upon the mouth through the floor of the antrum, and makes its way also through the somewhat slender anterior wall into the cheek. The densest part of the antrum wall is that in relation to the malar bone, and this part does not yield. There is little inducement for any growth to spread backwards, although it sometimes invades the zygomatic and ptery go-maxillary fossae. As the infra-orbital nerve runs along the roof of the antrum, while the nerves of the upper teeth are connected with its walls, these structures are pressed upon in growths springing from the antrum, and thus neuralgia of the face and teeth is often produced. In the operation of tapping the antrum a spot is usually selected just above the second bicus- pid tooth, since the bone is here thin and is con- veniently reached. In some cases it is sufficient to extract one of the molar teeth, since the fangs of these often enter the cavity of the antrum. The tooth usually selected is either the first or the third molar. Not infrequently the antrum com- municates at its upper anterior part with the frontal sinus. From Fig. 24 it will be seen that the antra descend below the level of the palate, and cannot be efficiently drained by an opening made above the palatal level. The opening of the antrum is shown in Figs. 24, 25 ; it is on a level with the roof of the cavity : hence if pus be present it drains most freely when the head is turned so that the affected chamber is uppermost; the sphenoidal sinus empties most easily when the head is bent forwards ; the frontal, when the head is thrown backwards. The cavity of the antrum is small if the inferior meatus is large or if the canine fossa of the face be well VI] THE ANTRUM 115 marked. The lymphatics of the sinuses drain into the retropharyngeal glands. As the result of a fall, one of the upper teeth has been entirely driven into the antrum and lost to view. In one case, reported by Haynes Walton, an upper in- cisor was found lying loose in the antrum three and a half years after the accident that had driven it there. CHAPTER VJI THE FACE The parts of the face, other than those already dealt with, will be considered under the fol- lowing heads: (1) The face generally; (2) the parotid region; and (3) the upper and lower jaws, and parts connected with them. The lips will be considered with the cavity of the mouth (Chap. viii.). 1. The Face Geneeally The skin of the face is thin and fine, and is more or less intimately adherent by a deli- cate subcutaneous tissue to the parts beneath. The skin generally is very freely supplied with sebaceous and sudoriparous glands, and hence the face is very commonly the seat of acne, an eruption that specially involves the sebaceous follicles. It happens from the thinness of the skin, and from the absence of dense fasciae, that facial abscesses usually soon point and seldom attain large size. The cellular tissue of the face is lax, and readily lends itself to spreading infiltrations, so that in certain inflammatory affections the cheeks and other parts of the face may become greatly swollen. In general dropsy, also, the face soon becomes " puffy/' the change first appearing as a rule in the lax tissue of the lower lid. The skin over the chin is peculiarly dense and adherent to the parts beneath, and in most respects closely 116 Chap. VII] BLOOD SUPPLY OF THE FACE 117 resembles the integument of the scalp. When such parts of the integuments of the face as cover prominent bones, such as the malar bone, chin, and the supra-orbital margin, are struck by a blunt instrument or in a fall, the wound pro- duced has often the appearance of a clean incised wound, just as obtains in contused wounds of the scalp. The mobility of the facial tissues renders this part very suitable for the performance of plastic operations of various kinds, and their vascularity generally ensures a ready and sound healing. Although there is a large quantity of fat in the subcutaneous tissue of this region, yet fatty tumours are singularly rare upon the face. They appear, indeed, to avoid this region. Thus, M. Denay reports the case of a man who had no fewer than 215 fatty tumours over different parts of his body, but not one upon his face. The face is peculiarly liable to be the seat of certain ulcers, especially rodent and lupoid ulcers, and is the part most often attacked by " malignant pustule/' a disease transmitted to man from cattle afflicted with a malady known in this country as " mur- rain, V and in France as " charbon. ;y Blood supply. — The tissues of the face are very vascular, and are liberally supplied with blood-vessels in all parts. The finer vessels of the skin often appear permanently injected or vari- cose in the drunken, or in those who are exposed to cold, or are the subjects of certain forms of acne. Thus nsevi and the various forms of erec- tile tumour are common about the face. # For a like reason also wounds of the face, while they may bleed readily when inflicted, are apt to heal with singular promptness and accuracy. All wounds, therefore, of this part should have their edges carefully adjusted as soon after the accident as possible. Extensive flaps of skin that have been torn up in lacerated wounds often retain their vitality in almost as marked a manner as do like flaps torn from the scalp. Extensive 118 THE HEAD AND NECK [Chap. injuries to the face associated with great loss of substance are often repaired in a remarkable manner, nor may such injuries be immediately fatal, as a case reported by Longmore shows : "An officer, of Zouaves, wounded in the Crimea, had his whole face and lower jaw carried away by a ball, the eyes and tongue included, so that there remained only the cranium, supported by the neck and spine.' ' He lived twentv hours. The pulsations of the facial artery can be best felt at the lower border of the jaw, where the vessel crosses just in front of the anterior border of the masseter muscle. It is here covered only by the integument and platysma, and can be readily compressed against the bone or ligatured. The anastomoses of the artery upon the face are so free that when the vessel is divided, both ends, as a rule, require to be secured. The facial vein is only in contact with the artery near the lower border of the jaw ; on the face it is separated from it by a considerable interval. The vein is not so flaccid as are most superficial veins; it remains more patent after section, it possesses no valves, and communicates at one end indirectly with the cavernous sinus, and at the other with the inter- nal jugular vein in the neck. This vein has also another, but less direct, communication with the intracranial veins. It is as follows : the facial vein receives the " deep facial vein " from the ptery- goid plexus, and this plexus communicates with the cavernous sinus by means of some small veins which pass through the foramen ovale and the fibrous tissue of the foramen lacerum medium. These dispositions of the facial vein may serve to explain the mortality of some inflammatory affections of the part. Thus carbuncle of the face is not infrequently fatal by inducing thrombosis of the cerebral sinuses, and a like complication may occur in any other diffuse and deeply extend- ing inflammatory condition. The unusual patency also of the facial vein favours septic absorption, and its direct communication with the great vein VII] BLOOD SUPPLY OF THE FACE 119 in the neck may explain those abrupt deaths from thrombosis that have followed upon the injection of facial nsevi in infants. A reference to the development of the face assists to explain the distribution of the fifth nerve and the occurrence of certain abnormalities (Fig. 27). The face is developed from five pro- cesses, a mesial, the fronto-nasal, and two lateral — the maxillary and mandibular. The fronto- Fig. 27. — Showing the development of the face. {Modified from Merkel.) F.N. P. , Part formed from the fronto-nasal process : L., from its lateral, and M., from its mesial parts ; MAX., formed by the maxillary process ; MAN., formed by the mandibular process. nasal process forms the middle part of the upper lip and the nose. It may fail to develop : thus the condition of cyclops is produced. It springs from the frontal region and carries with it a branch of the first division of the fifth, the nasal nerve. The second division of the fifth is the nerve of the maxillary process, while the third is that of the mandibular. Nerve supply. — The nerves of the face are very liberally distributed, the fifth being the 120 THE HEAD AND NECK [Chap. sensory nerve, the facial the motor (Fig. 4, p. 15). It follows, from the great number of nerve fila- ments about the part, and the extensive sensory nucleus of the fifth nerve, that severe irritants applied to the face may set up a widespread nerve disturbance. Dr. George Johnson mentions a case where a piece of flint embedded in a scar on the cheek set up facial neuralgia, facial paralysis, and trismus, and induced a return of epileptic attacks. The positions of the supra- and infra- orbital foramina and of the mental foramen and of the exit of the corresponding nerves are indi- cated as follows : # The supra-orbital foramen is found at the junction of the inner with the middle third of the upper margin of the orbit. A straight line drawn downwards from this point so as to cross the gap between the two bicuspids in both jaws will cross both the infra-orbital and mental foramina. The infra-orbital foramen is a little over J of an inch below the margin of the orbit. The mental foramen in the adult is midway be- tween the alveolus and the lower border of the jaw, and is a little over J of an inch below the cul-de-sac of mucous membrane between the lower lip and jaw. At puberty the foramen is nearer to the lower border of the maxilla, and in old age it is^ close to the alveolus. The inf ra=orbital nerve has been divided for neuralgia at its point of exit, the nerve being reached either by external incision or through the mouth by lifting up the cheek. In other cases the floor of the orbit has been exposed, the infra-orbital canal (the anterior half of which has a bony roof) has been opened up, and large portions of the trunk of the nerve have been in this way resected. Meckel's jrangflion has been repeatedly excised for the relief of neuralgia in- volving the second division of the fifth nerve. A triangular flap of skin is turned up from the front of the cheek, and the infra-orbital foramen is ex- posed. The anterior wall of the antrum is opened with a trephine, and the bone is cut away from the floor of the infra-orbital groove so that the VII] EXCISION OF MECKEL'S GANGLION 121 nerve lying in that canal is fully exposed. The nerve is followed back to the posterior wall of the antrum. This wall haying been trephined, the spheno-maxillary fossa is opened up and Meckel's ganglion exposed. Beyond the ganglion the fora- men rotundum can be made out. The infra-orbital artery runs with the nerve, and that vessel, to- gether with its anterior dental branch to the incisor and canine teeth, will probably be divided. Artic. Tuber 3RD DiV. Ext. P7£hygoid Plate Spheno-Max. Fossa Fig. 28. — Surface^markings for the second and third divisions of the fifth nerve. The infra-orbital yein^ ends in the pterygoid plexus. The ganglion is surrounded by the ter- minal branches of the internal maxillary artery. It is a triangular body, with a diameter of about J of an inch. It is a little convex on its outer side, and is of reddish colour. Operations such as that just described serve to recall the relationship of parts, but in practice they are now replaced by the simpler means of hypodermic injections. Absolute alcohol, in- 122 THE HEAD AND NECK [Chap. troduced into the trunk of a nerve, produces anaesthesia in the area of its distribution for six months or more. The successful performance of such injections requires a very accurate knowledge of the position and course of the nerves, and also of surrounding structures. The course of the second division of the fifth nerve is shown in Fig. 28. A point on the upper border of the zygoma, 6 mm. (J inch) behind the ascending margin of the malar, lies directly over the upper part of the spheno-maxillary fissure which con- tains the second division of the fifth nerve and Meckel's ganglion. To reach the nerve the needle has to be introduced 37 mm. (lj inches). An easier and safer route is along the floor of the orbit. The needle is inserted at the mid-point of the lower border of the orbit, and pushed back- wards along the floor, parallel to the sagittal plane of the head. The needle enters the spheno- maxillary fissure and fossa until it is arrested by coming in contact with the sphenoid at or near the foramen rotundum. By suitable manoeuvring the needle can be felt to enter the foramen rotundum. The depth of the foramen rotundum from the margin of the orbit is 43 mm. (If inches). The nerve may also be reached by introducing the needle below the zygoma and directing it upwards and inwards, but there is a grave risk of injuring the optic nerve if the needle should be thrust too far inwards. The inferior dental nerve has been divided at the mental foramen by an incision made through the buccal mucous membrane. Through this incision the nerve can be stretched and the cutaneous portion of it excised.^ Its trunk has been reached, and a part excised, through . a trephine hole made in the body of the lower jaw. This operation, however, inflicts great damage upon the bone, and cannot be recommended. The artery, moreover, is liable to be^ wounded. The nerve has been divided in the following manner before its entry into the mental foramen : VII] NERVE SUPPLY OF THE FACE 123 The mouth being held widely open, an incision is made from the last upper molar to the last lower molar just to the inner side of the anterior bor- der of the coronoid process, which can be clearly defined by palpation. The cut passes through the mucous membrane down to the tendon of the tem- poral muscle. The finger is introduced into the incision, and passed between the ramus of the jaw and the internal pterygoid muscle until the bony point is felt that marks the orifice of the dental canal. The nerve^ is here picked up with a hook, isolated, and divided. The buccal nerve supplies the, mucous membrane and skin of the cheek. It passes forwards on the outer surface of the buccinator muscle. The trunk of the third division of the fifth nerve leaves the middle fossa of the skull by the foramen ovale, the position of which corresponds to the lower border of the zygoma immediately anterior to the eminentia articularis (Fig. 28). To inject the trunk of the nerve, the needle is entered at this point and guided inwards against the under surface of the sphenoid until a depth of 37 mm. (l\ inches) is reached. Sensations referred along the nerve will tell the operator if the nerve has been reached. It is well to direct the needle a little forwards as well as inwards, for it^ will be then arrested by the external pterygoid plate; at the posterior border of this plate lies the foramen ovale. When a sensory nerve is divided the area of analgesia which results < does not correspond to its anatomical distribution. Thus, when the ophthalmic division of the fifth cranial nerve is cut, only a narrow strip of skin on the forehead is completely deprived of feeling, whereas from the anatomical distribution one would infer that the skin of the forehead and of the anterior half of the scalp shouklbe involved (see Fig. 4, p. 15). If the second division is cut, the area of anaesthesia is confined to a narrow space between the orbit and the mouth; on section of the third division, to a 124 THE HEAD AND NECK [Chap. strip running downwards in front of the ear and along the course of the lower jaw (Head). Head has offered an explanation of the vary- ing results which follow section of a sensory nerve. A nerve contains three kinds of sensory nerve fibres : (1) those subserving deep sensibility — endowing muscles, bones, ligaments, joints, and deep structures with the power to feel pressure and pain; (2) those subserving protopathic sensibility — by which the skin is rendered sensitive to prick Fig. 29. — The extent of loss of sensibility following (A) excision of the Gasserian ganglion, (B) section of the second cervical nerve. {After II. E. Tooth.) In the area stippled black there is a loss of protopathic sensibility ; in that stippled red, of epicritic sensibility. and to temperature, if it be above 40° or below 22°; (3) those subserving epicritic sensibility— by which the skin is endowed with the power of feel- ing light touch (tested with such a substance as cotton-wool) and finer degrees of temperature. Now, in the majority of instances, when a nerve is divided, the loss of epicritic sensibility corresponds in extent to the anatomical distribution of the nerve; when the Gasserian ganglion is removed {see Figs. 4 and 29) the loss of epicritic sensibility corresponds to the area of distribution, but the loss VII EXCISION OF GASSEEIAN GANGLION 125 of protopathic sensibility is less than the anatomi- cal area. It is evident that protopathic fibres from the second cervical nerve (Fig. 29) invade and sup- ply the area of skin furnished with epicritic sen- sibility by the fifth nerve. In the lower part of the face there is no overlapping of areas ; in the mental branch of the fifth, the epicritic and protopathic fibres are distributed to the same extent of skin. Thus the effects which follow section of a sensory Island of Ceil & Fissure oe Sylviu: Deep Temp. Fascia Temp. Muscle First Te/ip. Fissure Uncus Dura mater /liD.flEriiMQEAL Art- Root of zvqoma Ext Ptervqoid Aid AlENi/iqEAL Art Int. Max. Art Masseter CCRONOlD Proc Optic Tract Subarachnoid Space Cavernous Sinus hT Carotid Art Vl fb Qasserian CJanqlion Sphenoidal Sinus 3 rd Div of V^ h Lat RecessofPhar. Eustachian Tube.- Levator Palatae Fig. 30. — Coronal section to show the depth and relationships of the Gasserian ganglion. nerve depend on the nature of the fibres in that nerve, and on the extent of skin to which each kind is exclusively distributed. Excision of the Gasserian ganglion. — For cases of intolerable and intractable neuralgia Rose pro- posed the excision of the Gasserian ganglion. It is the sensory ganglion of the fifth nerve, and cor- responds to the ganglion on the posterior root of a spinal nerve. The nerve fibres of the fifth neces- sarily undergo degeneration when it is excised- The operation usually performed is the follow- 126 THE HEAD AND NECK [Chap. ing (see Fig. 30) : An omega-shaped flap of skin is raised from the temples, having the zygoma at its base and the temporal ridge at its convexity. The tissues are reflected down to the floor of the temporal fossa. The superficial and deep temporal vessels have to be tied. A wide trephine opening is made in the squamosal and great wing of the sphenoid on a level with the upper border of the zygoma, and the dura mater exposed. This is usually followed by profuse haemorrhage from the middle meningeal vessels which cross the field of operation. The dura mater and the superimposed temporo-sphenoidal lobe are raised from the bone, when the third and second divisions of the fifth nerve are brought into view as they escape by the foramen ovale and foramen rotundum. They are seen to spring from the Gasserian ganglion situ- ated over the apex of the petrous bone and on the outer wall of the cavernous sinus. The motor root which supplies the muscles of mastication lies under the ganglion and should not be cut. The ganglion is embedded in the dura mater and sur- rounded by a prolongation of the subarachnoid space (Meckel's space), which is necessarily opened. Only the part of the ganglion connected with the second and third divisions is removed, the part connected with the ophthalmic division being left, as it is firmly embedded in the outer wall of the cavernous sinus and in close proximity to the inter- nal carotid artery and the oculo-motor nerves. The hippocampal convolution containing the olfac- tory centre lies immediately over the ganglion (Fie:. 30). The eminentia articularis at the base of the zygoma serves as a useful guide to the position of the ganglion ; when the middle fossa is opened and the temporal lobe raised up the ganglion will be found at a depth of 2j inches and in the same coronal plane as the articular eminence, but at a higher level.* * For a full account of the anatomy of this operation see "The Surgical Treatment of Facial Neuralgia," by J, Hutchinson, jun, Jjopflon, J9Q5, VII] PAROTID GLAND 127 Malar bone. — Such is the firmness of this bone, and so direct is itsconnexion with the skull, that violent blows upon it are very apt to be asso- ciated with concussion. Resting as it does upon comparatively slender bones, it is very rare for the malar bone to be broken alone. It may, indeed, be driven into the superior maxillary bone, fracturing that structure extensively, without being itself in any way damaged. A fracture of the malar bone may lead to an orbital ecchymosis, precisely like that which often attends a fracture of the skull base. 2. The Parotid Region The main part of the parotid gland is lodged in a definite space behind the ramus of the lower jaw (Fig. 31). This space is increased in size when the^ head is extended, and when the inferior maxilla is moved forwards, as in protruding the chin. In the latter movement the increase in the antero-posterior direction is equal to about f of an inch. It is diminished when the head is flexed. When the mouth is widely opened the space is diminished below, while it is increased above by the gliding forwards of the con- dyle. These facts should be borne in mind in operating upon and in exploring the parotid space. It will be found also that in inflammation of the parotid much pain is produced by all those move- ments that tend to narrow the space occupied by the gland. The obliquity of the ramus of the jaw in infancy and old age causes the lower part of the space to be, in the former instance relatively and in the latter instance actually, larger than it is in the adult. The gland is closely; invested by a fascia derived from the cervical fascia. The superficial layer of the parotid fascia is very dense, continuous be- hind with the fibrous sheath of the sterno-mastoid, and in front with that of the masseter. Aboye^ it is attached to the zygoma, while below it Joins the deep layer. The fleep layer is slender, is 128 THE HEAD AND NECK [Chap. attached to the styloid process, forms the stylo- maxillary ligament, and is connected with the sheaths of the pterygoid muscles and the pterygoid process. The gland is, therefore, encased in a distinct sac of fascia, which is entirely closed below, but is open above. Between the anterior edge of the styloid pro- cess and the posterior border of the internal pterygoid muscle there is a gap in the fascia, through which the paro- tid space communicates with the connective tis- sue about the pharynx. It is well known that in postpharyngeal ab- Fig. 31. — Horizontal section through one side of the face and neck just above the level of the lower teeth. {Braune.) a, Facial artery ; &, facial vein : <*, gustatory nerve ; d, inferior dental nerve and artery lying internally to the ascending ramus of jaw ; &*£ S'.^^P^^A^tC^' and to the inner side of the last upper molar tooth. There are three principal methods of dividing these muscles : (1) Fergusson's : A small knife, with the blade at right angles to the stem, is passed through the cleft, and is made to divide the levator palati by an incision on the posterior aspect of the palate, trans- verse to the direction of the muscle. The tensor is not divided in this procedure. (2) Pollock's : A thin narrow knife, with the cutting edge upwards, is introduced into the isoft palate a little in front, and to the inner side, of the hamular process. The tendon of the tensor muscle is above the knife, and is cut as the knife is pushed upwards and inwards. The _. _ ._ knife is inserted until its Fl &: 36 -Muscles of point presents at the upper ^ . 8 °. ft palate ' from part of the cleft. As it is beh,nd - bi»incr wi+hrlrnwn if i« mnHp rt ' Levator palati ; 6, tensor bting Wltnarawn, It IS made palati ;c, hamular pro- to cut the posterior surtace cess ; d, wall of pha- of the velum to a sufficient depth to divide the leva- tor palati (Fig. 36). (3) Bryant's : Here the palate muscles are divided by a cut with the scissors that involves the entire thickness of the velum, the cut being at the side of the velum, and nearly parallel to the cleft. The blood supply of the soft palate is derived from the descending palatine branch of the in- ternal maxillary artery, the ascending pharyn- geal artery, and the ascending palatine branch of the facial artery. The latter vessel reaches the velum by following the levator palati muscle, and must be divided in the section made of this muscle in the procedures just described. rynx ; e, azygos uvulae ; f, the point of entry of the knife in Pollock's operation ; above it is the line of incision made on withdrawing the knife. 158 THE HEAD AND NECK [Chap. The muscles of the palate are supplied by several nerves. The levator palati, azygos uvulae, and palato-pharyngeus are inneryated with the muscles of the pharynx by the spinal accessory ; the palato-glossus with the muscles of the tongue from the hypo-glossal, and the tensor palati with the tensor tympani from the third division of the fifth nerve through the otic ganglion. The Pharynx The pharynx is about 5 inches in length. It is much wider from side to side than from before backwards. It is widest at the level of the tip of the greater cornua of the hyoid bone, where it measures about 2 inches. It is narrowest where it joins the gullet opposite the cricoid cartilage, its diameter here being less than } of an inch. The pharynx is not so large a space as supposed, for it must be remembered that during life it is viewed very obliquely, and erroneous notions are thus formed of its antero-posterior dimensions. The distance from the arch of the teeth to the commencement of the gullet is about 6 to 7 inches, a measurement that should be borne in mind in extracting foreign bodies. Foreign bodies passed into the pharynx are most apt to lodge at the level of the cricoid cartilage, a point that, in the adult, is a little beyond the reach of the finger. The history of foreign bodies in the pharynx shows that that cavity is very dilatable, and can accommodate for some time large sub- stances. Thus, in a case reported by Dr. Geoghc- gan, a man of 60, who had had for months some trouble in his throat for which he could not account, was supposed to have cancer. On ex- amination, however, a plate carrying five false teeth, and presenting niches for five natural ones, was found embedded in the pharynx, where it had been lodged for five months. The plate had been swallowed during sleep {Med. Press, 1866). In the Lancet for 1868 is an account of a mutton chop that became lodged in the pharynx of a VIII] THE PHARYNX 159 gluttonous individual. The chop presented the ordinary vertebral segment of bone, together with lj inches of rib, and was " pretty well covered with meat." Attempts to remove it failed, and it was finally vomited up. Dr. Hicks (Lancet, 1884) reports the case of a woman who committed suicide by cramming half a square yard of coarse calico (belonging to her nightdress) into her mouth and throat. The walls of the pharynx are in relation with the base of the skull, and with the upper six cer- vical vertebrae. The arch of the atlas is almost exactly on a line with the hard palate. The axis is on a line with the free edge of the upper teeth. The termination of the pharynx corresponds to the sixth cervical vertebra. The upper vertebrae can be examined, as regards their anterior sur : face, from the mouth. When the bones about the pharynx are diseased, the necrosed parts may be discharged by that cavity. Thus portions of the atlas and axis have been expelled by the mouth, as also have been some fragments of comparatively large size thrown off by the occipital and sphenoid bones. The mucous membrane of the pharynx is vas- cular, and readily inflamed; and such inflamma- tions are peculiarly dangerous, in that they may spread to the lining membrane of the larynx. The submucous tissue of^ the aryteno-epiglottic folds and of the neighbouring part of the pharynx is peculiarly loose, and in cedematous conditions the upper aperture of the larynx may be almost closed. Much adenoid tissue is distributed in the mucous membrane of the pharynx, and it is this tissue that is the primary seat of inflammation in scrofulous pharyngitis. A distinct collection of adenoid tissue — the naso-pharyngeal tonsil — is found in the roof of the naso-pharynx (see. Figs. 37 and 25). It is embedded in the thick mucous membrane, and extends from the base of the septum of the nose to the mid-point of the 160 THE HEAD AND NECK [Chap. Roof of Naso-Pharynx Pharyng Tonsil Opening of Eustach Tube Soft Palate basilar process of the skull. The centre of the ton- sil is marked by a fissure or depression bounded on each side by two or three folds of mucous membrane laden with adenoid tissue. It reaches its maximum size about the tenth year. It ex- tends laterally towards the recesses behind the Eustachian tubes, and may invade these recesses and thus prevent the free opening of the tubes. This deposit of adenoid tissue may undergo hypertrophic change, and the condition known as "adenoid vegetations" or "post-nasal growths" be produced. These growths may cause deafness and may block the pos- terior nares. They need to be removed by operation. The tissue imme- diately outside the pharyngeal walls is lax, and favours the spread of effu- sion. Thus, in acute inflammation of the pharynx the effusion Fig. 37. -Tonsil of the nasopharynx has been found to of a boy aged 2 years. extend along the ( From a preparation made by Professor oesophagus, reach- Symington.) mg the posterior mediastinum, and advancing even to the diaphragm. In the lax connective tissue between the pharynx and the spine abscess is not infrequent, due, as a rule, to caries of the vertebrae (postpharyngeal abscess). In this connective tissue, and opposite the axis, is also found a lymphatic gland that receives lymphatics from the nasal cavity and naso- pharynx. This gland may prove the seat of a suppuration. Such collections may so push tor- ward the posterior pharyngeal wall as to depress the soft palate, or may cause severe dyspnoea by interference with the larynx. The matter may discharge itself through the mouth, or may reach Post. Border of Septum Nasi VIII] THE TONSIL 161 the neck by passing behind the great vessels and the parotid gland, presenting ultimately beneath or at one border of the sterno-mastoid muscle. Many structures of importance are in relation with the lateral walls of the pharynx, the prin- cipal being the internal carotid artery, the vagus, glossopharyngeal, and hypoglossal nerves (Fig. 31, p. 128). The internal carotid is so close to the pharynx that its pulsations may be felt by the finger introduced through the mouth. These, and other deep structures in the neck, may be wounded by foreign bodies that, passing in at the mouth, have been thrust through the pharynx into the cervical tissues. The internal jugular vein is at some distance from the pharynx, especi- ally at its upper part (Fig. 31, p. 128). The styloid process, when prominent, and an ossified stylo-hyoid ligament, can also be felt at the side of the pharynx immediately behind the tonsil. In more than one case an ossified stylo-hyoid ligament has been mistaken for a foreign body, and an attempt made to excise it. The tonsil is lodged between the anterior and posterior palatine arches. It is in relation externally with the superior constrictor muscle (Fig. 31, p. 128), and corresponds, as regarls the surface, to the angle of the lower jaw. When hypertrophied, the mass tends to develop towards the middle line, where no resistance is encountered, and to effect but little change in its external relations. The mass, often mistaken for the enlarged tonsil in the neck, is formed of enlarged glands, situate near the tip of the great cornu of the hyoid bone, and overlying the internal jugular vein. These glands receive the tonsillar lymphatics, and are almost invari- ably enlarged in all tonsil affections. The fact that these glands are so frequently the first to en- large when the cervical glands become tubercular points to the tonsil as a common site of primary infection. The tonsil is closely enough attached to the pharyngeal wall to be affected by the movements 162 THE HEAD AND NECK [Chap. of the pharyngeal muscles. Thus it is moved in- wards by the superior constrictor muscle during the act of swallowing, and may be drawn out- wards, on the other hand, by the stylo-pharyngeus muscle. The ease with which a tonsil can be reached depends, other things being equal, upon the extent to which it can be withdrawn by the stylo-pharyngeus, and upon the development of the anterior palatine arch, which, to some extent, hides the tonsil. A child with a prominent an- Hard Palate 2 Soft Palate Plica Semilunaris Post. Pillar Tonsil Plica Triangularis Fig. 38. — Diagram of the pillars of the fauces and of the tonsil. terior palatine arch, containing a well-developed palato-glossus muscle, and with a vigorous stylo- pharyngeus, can for a long time elude the tonsil guillotine. The tonsil is variable in shape ; it is frequently divided into three masses, and, besides numerous crypts, shows towards its upper part, where the anterior and posterior pillars meet with the soft palate, a deep recess or pocket — the tonsillar recess. This recess is the remnant of the first visceral cleft in which the tonsil was developed (Seccombe Hett). From the anterior pillar a VIII] THE TONSIL 163 sharp fold of mucous membrane passes back- wards, to end on the tonsil — the plica triangularis (sec Fig. 38) — while another fold may join the pillars over the tonsillar recess {plica semilunaris) . The tonsil is separated from the superior con- strictor by a fine fibrous capsule ; its lymphatics perforate the constrictor Two chief forms of tonsil may be recognized : the embedded, where the adenoid tissue increases beneath the level of the pillars ; and the projecting, where the increase affects chiefly the exposed part of the tonsil (S. Hett). Deafness is often complained of when the tonsil is hypertrophied. This is not due to closure of the Eustachian tube by the direct pressure of the enlarged mass. Such pressure is anatomically im- possible. The large tonsil may, however, affect the patency of the tube, by disturbing the soft palate, and through it the tensor palati muscle, which is much concerned in keeping open the Eustachian tube. The deafness in these cases is probably due rather to an extension of the hyper- trophic process to the lining membrane of the tube than to any pressure effects, since it is usually not improved until some time after the tonsil has been removed. The tonsil tissue is for the most part collected around a number of crypts. The decomposition of retained epithelial structures within these recesses produces the fetid breath often noticed in cases of enlarged tonsil, and probably incites the attacks of inflammation to which such tonsils are liable, Calculi may form in these crypts and give rise to a spasmodic cough. In this case the glosso-pharyngeal nerve conveys the afferent impulse to the respiratory centre. The tonsil is very vascular, receiving blood from the tonsillar and palatine branches of the facial artery, from the descending palatine branch of the internal maxillary, from the dorsalis lin- guae of the lingual, and from the ascending pharyngeal. Hence the operation of removing 164 THE HEAD AND NECK [Chap.VlIl the tonsil is often associated with free bleeding. The internal carotid artery is close to the pharynx, but some way behind the gland (Fig. 31, p. 128). The vessel is, indeed, about f of an inch posterior to that body, and is in comparatively little danger of being wounded when the tonsil is excised. The internal jugular vein is a con- siderable distance from the tonsil. The facial artery, in its cervical stage, is close to the tonsil. Of important cervical structures, the nearest to the tonsil is the glosso-pharyngeal nerve. The ascending pharyngeal artery is also in close re- lation with it. Although this vessel is of small size, bleeding from it has proved fatal, as the following interesting case, reported by Mr. Mor- rant Baker, will show : A man, aged 23, fell when drunk, and grazed his throat with the end of a tobacco-pipe he was smoking at the time. He thought nothing of the accident. In two days he came to the hospital with what appeared to be an acutely inflamed tonsil. The tonsil was punctured, but nothing escaped save a little blood. Several haemorrhages occurred from the tonsil wound, and on the fourth day after the accident 1 inch of the stem of a clay pipe was discovered deeply embedded in the glandular substance. It was removed, and the common carotid tied. The patient, however, never rallied from the previous severe haemorrhages, and soon died. The autopsy showed that the stem of the pipe, which had not been missed by the patient, had divided the ascending pharyngeal artery (St. Bart:s Hasp. Rejwrts, 1876). The tonsil is often the seat of malignant growths. Such tumours have been removed through the mouth, but are more conveniently dealt with through an incision in the neck along the anterior edge of the sterno-mastoid (Cheever's operation). CHAPTER IX THE NECK Surface anatomy; bony points,— The hyoid bone is on a level with the fourth cervical vertebra, while the cricoid cartilage is opposite the sixth. The upper margin of the sternum is on a level with the disc between the second and third dorsal vertebrae. (See p. 180.) At the back oi the neck there is a slight depression in the middle line which descends from the occipital protuber- ance, and lies between the prominences formed by the trapezius and complexus muscles of the two sides. At the upper part of this depression the spine of the axis can be made out on deep pres- sure. Below this, the bony ridge formed by the spines of the third, fourth, fifth, and sixth cervi- cal vertebrae can be felt, but the individual spines cannot usually be distinguished. At the root of the neck the spinous process of the vertebra prominens is generally very obvious. The trans- verse process of the atlas may be felt just below and in front of the tip of the mastoid process. By deep pressure in the upper part of the supra^ clavicular fossa, the transverse process of the seventh cervical vertebra can be distinguished. If pressure be made over the line of the carotid vessels at the level of the cricoid cartilage, the prominent anterior tubercle of the trans- verse process of the sixth cervical vertebra can be felt. This is known as the " carotid tuber- cle.^ The carotid artery lies directly over it, 165 166 THE HEAD AND NECK ' [Chap. and in ligaturing that vessel some surgeons make important use of this tubercle as a landmark. If a horizontal section of the neck, in a muscular subject, taken about the level of the sixth cervical vertebra, be viewed, the whole of the body of the vertebra divided will be seen to lie within the anterior half of the section. Middle line. — In the receding angle below the chin the hyoid bone can be felt and its body and greater cornua well made out. About a finger's-breadth below it is the thyroid cartilage. The details of this latter are readily distin- guished, and below it the cricoid cartilage, crico- thyroid space, and trachea can be easily recog- nized. The separate rings of the trachea cannot be felt. The trachea is less easily made out as it passes down the neck. As it descends it takes a deeper position, and at the upper border of the sternum lies nearly \\ inches from the surface. The rima glottidis corresponds to the middle of the anterior margin of the thyroid cartilage. Unless enlarged, the thyroid gland cannot be made out with certainty. According to Mr. Holden, the pulse of the superior thyroid artery can be felt at its upper and anterior part. The anterior jugular veins descend on either side of the middle line upon the sterno-hyoid mus- cles. They commence in the submaxillary region, pierce the fascia just above the inner end of the clavicle, and, passing beneath the origin of the sterno-mastoid muscle, end in the external jugu- lar. The inferior thyroid veins lie in front of the trachea, below the isthmus. Side of the neck. Muscles. — The sterno- mastoid muscle, especially in thin subjects and when thrown into action, is a prominent feature in the neck. The anterior border of the muscle is very distinct. The posterior border is less promi- nent, especially at its upper part. A communi- cating branch from the facial vein generally runs along the anterior border of the muscle to meet the anterior jugular vein at the lower part of IXJ VESSELS OF THE NECK 167 the neck. The interval between the sternal and clavicular parts of the muscle is generally well marked. If a needle be thrust through this in- terval, quite close to the clavicle, it would just touch the bifurcation of the innominate artery on the right side and would pierce the carotid vessel on the left. The posterior belly of the digastric muscle corresponds to a line drawn from the mastoid process to the anterior part of the hyoid bone. The anterior belly of the omo-hyoid follows an oblique line drawn downwards from the fore part of the hyoid bone, so as to cross the line of the carotid artery opposite the cricoid cartilage. The posterior belly can be made out in thin necks, especially when in action, running nearly parallel with and just above the clavicle. Although not taking quite the same direction, yet the posterior borders of the sterno-mastoid and anterior scalene muscles practically correspond to one another. Vessels. — The common carotid artery is repre- sented by a line drawn from the sterno-clavicular joint to a point midway between the angle of the jaw and the mastoid process. The vessel bifur- cates at the upper border of the thyroid cartilage, or not infrequentlv nearly J an inch above that point. The omo-hyoid crosses it opposite the cricoid cartilage, and at about the same level the artery is crossed by the middle thyroid vein. The line of the internal jugular vein is just external to that for the main artery. Both the artery and vein lie under the anterior border of the sterno- mastoid. The superior thyroid artery comes off below the great cornu of the hyoid bone, and curves forwards and downwards to the upper edge of the thyroid cartilage. The great cornu of the hyoid serves as an excellent guide to the lin- gual artery, which invariably forms a loop above the posterior end of that process before proceeding forwards beneath the hyo-glossus muscle (Fig. 32). The facial artery is very tortuous, but its general course in the neck is represented by a line 168 THE HEAD AND NECK J [Chap. drawn from the anterior border of the masseter at the lower border of the jaw to a point just above the tip of the great cornu, while the occi- pital follows a line that starts from the latter point and runs across the base of the mastoid process. The external jugular vein follows a line drawn from the angle of the jaw to the middle of the clavicle. BRACK PLEX Mid. Point Clav. - Mid. Point Clav. Axill. Art. Subclav. Art. Vert. Art. Fig. 39. — Diagram showing the surface markings for the brachial plexus, subclavian and carotid arteries. The subclavian artery describes a curve at the root of the neck (Fig. 39). One end of the curve corresponds to the sterno-clavicular joint, the other end to the centre of the clavicle, the summit of the curve rising to a point about \ an inch above that bone. In the angle between the posterior edge of the sterno-mastoid and the clavicle the pulsa- tions of the artery may be felt. Just above the bone the artery may be compressed against the first rib. The compression is most easily applied when the arm is well drawn down, and the 1X1 NERVES OF THE NECK 169 direction of the pressure should be downwards and inwards. The subclavian vein lies below the artery, and is entirely under cover of the clavicle. The suprascapular and transverse cervical arteries run parallel with the clavicle, the former quite behind the bone, the latter just above it. The pulsations of the latter vessel can generally be felt. Nerves.— The position of the chief superficial nerves of the neck may be fairly indicated by six lines, all drawn from the middle of the pos- terior border of the sterno-mastoid muscle. A line drawn forwards from this spot so as to cross the sterno-mastoid at right angles to its long axis corresponds to the superficial cervical nerve. A second line drawn up across the muscle to the back of the pinna, so as to run parallel with the external jugular vein, corresponds to the great auricular nerve; and a third line, running along the posterior border of the sterno-mastoid muscle to the scalp, marks the course of the small occi- pital nerve. These lines, continued downwards, so as to cross the sternum, the middle of the cla- vicle, and the acromion, will indicate respectively the suprasternal, supraclavicular, and supra- acromial nerves. The spinal accessory nerve reaches the anterior border of the sterno-mastoid muscle at a point about 1 inch below the tip of the mastoid process. It emerges from beneath that muscle about the middle of its posterior border, crosses the pos- terior triangle, and passes beneath the trapezius between the middle and lower thirds of the anterior border of that muscle (Fig. 32, p. 130). The phrenic nerve commences deeply at the side of the neck, about the level of the mid-point of the thyroid cartilage, and runs downwards to a point behind the sternal end of the clavicle. About the level of the cricoid cartilage it lies beneath the sterno-mastoid (which covers it wholly in the neck) about midway between the anterior G* 170 THE HEAD AND NECK [Chap. and posterior borders of the muscle. The brachial plexus can be felt, and even seen in very thin subjects. Its upper limits may be represented by a line drawn across the side of the neck from a point about opposite to the crico-thyroid space to a spot a little external to the centre of the clavicle. The skin in the submaxillary region is lax and thin, and is often found of considerable value for making flaps in plastic operations about the mouth. The platysma myoides is closely con- nected with the skin, and to its action is due the turning-in of the edges of such wounds as are athwart the line of direction of the muscle. The amount of subcutaneous fat in the cervical re- gion varies in different parts. In the suprahyoid region it is apt to undergo extensive development, producing the diffused lipoma known as ■' double- chin. " The skin over the nape of the neck is very dense and adherent, and these two circumstances, in addition to the free nerve-supply of the parts, serve to explain the severe pain that often accom- panies inflammation in this region. Common car- buncle is very often met with behind at the root of the neck, in the middle line. When the stcrno-mastoid muscle of one side is rigidly contracted, either from paralysis of the opposite muscle or from spasmodic contraction, or from some congenital defect, the condition known as wry-neck is produced. The position of the head in wry-neck illustrates precisely the effect of the sterno-mastoid when in full action. The head is bent a little forwards, the chin is turned towards the sound side, and the ear on the affected side leans towards the sternoclavicular joint. In many cases the trapezius and splenius muscles are also affected. Spasmodic contraction of the muscle may be due to reflex irritation. Thus, it has accompanied inflammation of the cer- vical glands in the posterior triangle. Such in- flammation has irritated some branches of the IX] THE STERNO-MASTOID 171 cervical plexus, and the sterno-mastoid muscle, although it is supplied mainly by the spinal acces- sory nerve, receives a nerve from that plexus (viz. from the second cervical). The course of the re- flex disturbance in such cases is therefore not dim- cult to follow. It is to be remembered, too, that the spinal accessory nerve passes between the upper two or three deep cervical lymph glands which may compress it. A like contraction has also been produced by direct irritation of the second cervical nerve in cases of disease of the first two cervical vertebrae. For the relief of some forms of wry-neck, the sterno-mastoid muscle is divided subcutaneously, as in an ordinary teno- tomy operation, about \ an inch above its attach- ment to the sternum and clavicle. Two structures stand considerable risk of being wounded in this operation, viz., the external iugular vein lying near the posterior border of the muscle, and the anterior jugular which follows its anterior border and passes behind the muscle, just above the clavicle, to terminate in the first-named vein. With common care, there should be no risk of wounding the great vessels at the root of the neck. For spasmodic wry-neck the spinal accessory nerve and the communicating branches of the second and third cervical nerves have been cut. The spinal accessory nerve is found at the an- terior border of the sterno-mastoid, 1 inch below the mastoid process. There is a curious congenital tumour, or in- duration, sometimes met with in this muscle in the newly born. It is usually ascribed to syphilis, but, in most cases, is probably due to some tear- ing of the muscle fibres during the process of delivery. Cervical fascia. — To the connective tissue which binds together the muscles, vessels, nerves, and glands of the neck the name of cervical fascia is given. It consists of the sheaths of the muscles, vessels, and nerves. These sheaths are united together in such a manner as to 172 THE HEAD AND NECK ![Chap. allow free movements of the oesophagus, larynx, and trachea, and yet to give a firmness and solidity so that the neck may be moved as a whole. Besides serving as a medium for binding the various structures of the neck together, the cervical fascia forms the supporting tissue in which the extensive lymphatic system of the neck is embedded and conveyed towards the root of the neck. The deep cervical fascia may be divided into (a) the superficial layer, and (b) the deeper pro- cesses (see Fig. 40). (a) The superficial layer forms a complete in- vestment for the neck, and covers in all the cer- vical structures, except the platysma and some superficial veins and nerves, with the complete- ness of a perfectly fitting cravat. It commences as a thin layer behind at the spinous processes of the vertebrae, and, having invested the trapezius muscle, starts, at the anterior border of that muscle, as a single layer, to cross the posterior triangle. Arriving at the posterior border of the sterno-mastoid muscle, it splits to enclose that structure, appearing again as a single layer at the anterior border of the muscle, from whence it passes to the middle line of the neck to join the fascia of the opposite side, entirely covering in, on its way, the anterior triangle. The part that occupies the posterior triangle is loose and open in texture, and is continuous with the connective tissue of that triangle. Over the anterior triangle the fascia is attached above to the border of the lower jaw. Behind that bone it passes over the parotid gland to the zygoma, forming the parotid fascia, while a deeper layer passes beneath the gland (between it and its submaxillary colleague), to be attached to points at the base of the skull. It is from this deeper part that the stylo-maxil- lary ligament is developed. In front the fascia is attached to the hyoid bone, and just belpw the thyroid body it divides into two layers again, one to be attached to the front of the sternum and the ixi CERVICAL FASCIA 173 other to the back. Both of these layers lie in front of the depressors of the hyoid bone, and they form between them a little space (which extends so far laterally as to enclose the sternal head of the sterno-mastoid), the widest part of which is below, and which there corresponds in width to the Fig. 40. — Transverse section through the lower part of the neck, to show the arrangement of the cervical fascia {diagrammatic). a, Trapezius ; b, sterno-mastoid ; c, depressors of hyoid bone ; d, pla- tysma ; e anterior spinal muscles ; /, scalenus anticus ; g, carotid artery ; h, external jugular vein ; i, posterior spinal muscles ; T, trachea, with gullet behind and thyroid body in front. thickness of the sternum. It will be perceived that, in dividing the sternal head of the sterno- mastoid, the operation is performed within this little chamber formed by the two layers just named, and it is well to note that the anterior jugular vein also occupies this chamber on its way to the external jugular trunk. 174 THE HEAD AND NECK [Chap. (b) The deeper processes.— (1) From the super- ficial layer a process comes off near the anterior border of the sterno-mastoid muscle, which, pass- ing beneath the depressors of the hyoid bone, in- vests the thyroid body and front of the trachea, and passes down, in front of that tube and of the large vessels, to the fibrous layer of the peri- cardium. (2) The prevertebral fascia is a layer that descends on the prevertebral muscles behind the pharynx and gullet. It is attached above to the base of the skull, and, below, descends into the thorax, behind the oesophagus. Laterally, it joins the carotid sheath, and is then prolonged outwards and downwards over the scalene muscles, the brachial plexus, and subclavian vessels. It follows these vessels beneath the clavicle, where it forms the axillary sheath and becomes con- nected with the under surface of the costo-cora- coid membrane. (3) The sheath of the carotid artery and its accompanying vein and nerve is continuous with the prevertebral and pretracheal layers and with the sheath of the sterno-mastoid (Fig. 40). The carotid sheath descends with the pretracheal layer, to end in the^ sheath of the aorta and pericardium. Hence, in a sense, the heart and pericardium are supported from the neck ; when the head is thrown back the carotid sheaths become tense and the thoracic structures are lifted upwards. In many cases a cervical abscess has burst into the gullet, or trachea, and even into the pleura. In some instances the great vessels have been opened up. In one remarkable case reported by Mr. Savory (Med.-Chir. Trans., 1881), not only was a considerable portion of the common carotid artery destroyed by the abscess, but also a still larger portion of the internal jugular vein and a large part of the vagus nerve. This, and like examples of the destructive action of some cervical abscesses, depend, no doubt, upon the unyielding character of the cervical fascia, which hems in the pus on all sides, and drives it to resort to IX] APEX OF THE LUNG 175 desperate measures to effect an escape. " It is noteworthy, " remarks Mr. Jacobson, " that com- munications between abscesses and deep vessels have usually taken place beneath two of the strongest fasciae in the body, the deep cervical fascia and the fascia lata " (Hilton's " Rest and Pain "). ! The apex of the lung extends into the neck, and reaches a point from 1 to 2 inches above the inner half of the clavicle. A point between the sternal and clavicular heads of the sterno-mastoid and lj inches above the clavicle will, in the majority of adults, mark the highest point of the apex and the position of the neck of the first rib. It lies behind the clavicle, anterior scalene muscle, and subclavian vessels. The right lung commonly extends higher up than the left. The pleura has been opened in careless opera- tions on the subclavian artery, and has also been torn in dragging deep-seated tumours from the base of the neck. The pleura and lung have been wounded in stabs of the neck and by fragments of bone in severe fractures of the clavicle. Cer- vical abscesses have opened into the pleura, and, apart from this, pleurisy has followed inflamma- tion of the cellular tissue at the root of the neck. Sibson's fascia, which is attached along the inner border of the first rib, strengthens the pleura over the apex of the lung. Cervical ribs. — These structures have led to many errors in diagnosis, have been mistaken for exostoses, and where the subclavian artery is carried over them, which is usually the case (Fig. 41), have led to the diagnosis of aneurysm. They are met with at all ages and in both sexes, and represent the cervical ribs of lower vertebrates. In most cases one such rib is found on either side of the seventh cervical vertebra ; sometimes it is movable, sometimes it is ankylosed to the vertebra and its transverse process. A rudiment is always present in the foetus. It may be very short, and represented only by a head, neck, and tubercle. 176 THE HEAT) AND NECK [Chap. Such forms have been mistaken for exostoses. It may be long, and may then end free, or be joined to the first rib or the first costal cartilage by ligament, or even by cartilage. In such in- stances the subclavian artery passes over the cervical rib, its pulsations being very distinctly Fifth Cerv./Ierve ^Carotid Tubercle Trac/iea iElCMTM Cerv./Ierve +Cervical Rib J.5uBCLAviAn Art. Carotid Art. Sibson's Fascia Imomiaiate Art. Clavtcle ANUBR.IUM Fig. 41. — Showing the relationship of the subclavian artery and brachial plexus to a cervical rib. seen and felt. To the longer form of cervical ribs the scalenus anticus and the scalenus medius may be attached. Occasionally subjects of this anomaly complain of numbness along the ulnar side of the arm and hand, or of partial paralysis of the muscles of the hand. These symptoms are due to traction on the first dorsal nerve at the IX] WOUNDS OF THE NECK 177 point where it crosses above the cervical rib (Thorburn). (See Fig. 41.) Cervical ribs with associated pressure symptoms may be traced through several generations of the same family (Theodore Thompson). In thin subjects the rib can be seen as a distinct projection in the neck. Dr. Wood-Jones has pointed out that the groove on the upper surface of the first rib is occupied, not by the subclavian artery, but by the lowest trunk of the brachial plexus formed by the eighth cervical and first dorsal nerves. He has also shown that the groove is deepest, and the pres- sure between the nerve trunk and rib therefore greatest, in those cases where a considerable part of the second dorsal nerve enters into the forma- tion of the lowest trunk of the brachial plexus. Cut throat and wounds of the neck.— The skin of the neck is so elastic and mobile that it is readily thrown into folds when a knife, and especially a blunt knife, is drawn across it. Thus in cases of cut throat several distinct skin- cuts may be found that were all produced by one movement of the knife. The wound in cut throat, whether suicidal or homicidal, most frequently involves the thyro-hyoid membrane, next in fre- quency the trachea, and then the thyroid car- tilage. (See Fig. 39.) 1. If the wound be above the hyoid bone the following parts may be cut : Anterior jugular vein ; anterior belly of digastric ; mylo-hyoid, genio-hyoid, genio-hyo-glossus, and hyo-glossus muscles ; the lingual artery ; branches of the facial artery; the ^ hypoglossal and gustatory nerves; the submaxillary gland. The substance of the tongue may be cut, and the floor of the mouth freely opened. In any case where the attachments of the tongue are divided the organ is apt to fall back upon the larynx and produce suffocation. 2. If the wound be across the thyro-hyoid space the following may be the parts cut : Anterior jugular vein; sterno-hyoid, thyro-hyoid, omo- hyoid muscles; thyro-hyoid membrane; inferior 178 THE HEAD AND NECK [Chafe. constrictor ; superior laryngeal nerve ; superior thyroid artery; and if near the hyoid bone the trunk of the lingual artery may be cut. The pharynx would be opened in a deep wound, and the epiglottis divided near its base. Division of the epiglottis in wounds in this situation is always a serious complication. 3. If the wound involve the trachea the follow- ing may be the parts cut : Anterior jugular vein ; sterno-hyoid, sterno-thyroid, and omo-hyoid muscles ; part of sterno-mastoid ; thyroid gland ; superior and inferior thyroid arteries; superior, middle, and inferior thyroid veins; recurrent laryngeal nerves and the gullet. In wounds of the neck the great vessels often escape in a marvellous manner. They are pro- tected in part by the depth at which they are situated, and in part by their great mobility, lying as they do in an atmosphere of loose con- nective tissue. Dieffenbach relates a case of cut throat in which both gullet and trachea were divided without any damage to the great vessels. In cut throat the vessels are greatly protected by the projecting thyroid cartilage above and by the contracting of the sterno-mastoid muscles below. Deep gashes made across the crico-thy- roid space, or through the upper part of the trachea, reach the great vessels more easily than would wounds made with equal force in any other part of the neck. In some cases of gunshot wound the vessels seem to have been actually pushed aside, and to have owed their safety to their mobility. Thus, in a case reported by Longmore, the bullet passed entirely through the neck from one side to the other. It passed through the gullet, damaged the posterior part of the larynx, but left the great vessels intact. In another recorded case a boy fell upon the point of a walking-stick. The end of the^ stick passed entirely through the neck from side to side, entering in front of one sterno- mastoid muscle and emerging through the sub- IX] HYOID BONE 179 stance of the opposite one. It probably passed between the pharynx and the spine. The boy, who left the hospital well in eighteen days, owed his safety to the laxity of the cervical connective tissue and to the mobility of the main structures in the neck. The structures of the neck are fixed laxly to allow movements of the larynx and tongue. In connexion with the subject of wounds of the neck, it must be remembered that the most im- portant part of the spinal cord can be reached from behind, through the gap between the atlas and axis. In this situation the cord has been divided by one stab of a knife, the instrument entering between the two bones. Langier gives some ingenious cases of infanticide where the lethal weapon was merely a long^ needle. The needle was introduced into the spinal canal be- tween the atlas and the axis, and the cord readily cut across. The hyoid bone maybe broken by direct vio- lence, as from blows, or in the act of throttling. It is sometimes found broken in those who have been hanged. The fracture may involve the body of the bone, but more usually the greater cornu is found broken off. In the New York Medical Record (1882) is published the report of the case of a man who felt something snap under his chin while yawning. On examination the hyoid bone was found to be fractured. The bone was also found broken in a patient who threw her head violently backwards to save herself from fall- ing (Hamilton). The fracture is associated with great difficulty and pain in speaking, in moving the tongue, in opening the mouth, and in swallow- ing — symptoms that may be readily understood. A bursa lies between the thyro-hyoid membrane and the posterior surface of the hyoid^ bone. It may, when enlarged, form one of the cystic tumours of the neck. f^arynx and trachea.— The position of the larynx in the neck is influenced by age. In the 180 THE HEAD AND NECK [Chap. adult the cricoid cartilage reaches to the lower part of the sixth cervical vertebra. In a child of three months it reaches the lower border of the fourth cervical, and in a child of six years the lower border of the fifth vertebra. At puberty it attains the adult position. The upper end of the epiglottis in the adult is opposite the lower border of the third cervical vertebra. With the laryngoscope the following parts may be made out (Fig. 42) : The base of the tongue and glosso- epiglottic ligaments ; the superior aperture of the larynx, presenting in front the epiglottis, at the sides the aryteno-epiglottidean folds (in which are two rounded eminences corresponding to the cornicula and cuneiform cartilages), and at the back the arytenoid commissure of mucous membrane. Deeply down can be seen the true and false vocal cords, the ventricle, the anterior wall of the larynx, a little of the cricoid cartilage, and more or less of the anterior wall of the trachea. > If the glottis be very fully dilated the openings of the two bronchi may be dimly seen. The thyroid and cricoid cartilages and the greater part of the arytenoid are in structure hyaline, as are the costal cartilages. Like the last-named, they are liable to become more or less ossified as life advances. Ossification commences in the thyroid and cricoid cartilages at about the age of 20, and in either cartilage the process commences in the vicinity of the crico-thyroid joint. The arytenoid ossifies later. Ossification of the laryngeal cartilages is more marked in males than in females. The larger cartilages are liable to be fractured by violence, as by blows, throttling, etc. The thyroid is the one most fre- quently broken, and usually in the median line. The posterior superior^ angle of the thyroid car- tilage marks the position of the pyriform fossa, a wide recess, above and external to the aryteno- epiglottic folds (Fig. 42). Foreign bodies may be arrested in this fossa. IX] RIMA GLOTTIDIS 181 The rima glottidis is the aperture between the true vocal cords and the vocal processes of the arytenoid, to which the cords are attached pos- teriorly. The cords are double the length of the processes, and are of a grey buff colour, owing to the elastic tissue, of which they are mainly composed, being apparent beneath the stratified epithelium. The rima is the narrowest part of the interior of the larynx, and it is well to be familiar with its proportions in reference to the Fig. 42. —Upper aperture of the larynx in the open (A) and shut (b) positions. A, Cushion of epiglottis ; B, apices of arytenoids ; C, aryteno-epi- glottidean folds ; E, posterior aspect of cricoid ; F, false vocal cords ; G, rima glottidis, between true vocal cords ; H, posterior border of thyroid cartilage ; I, tip of great horn of hyoid. entrance of foreign bodies and the introduction of instruments. In the adult male the rima mea- sures nearly 1 inch (23 mm.) from before back- wards; from side to side, at its widest part, it measures about one-third of the length ; this dia- meter may be increased to one-half of the length in extreme dilatation. In the female and in the male before puberty the antero-posterior diameter is from 17 mm. The rima is widely opened dur- ing inspiration, owing to the action of the crico- arytenoideus posticus, while the vocal cords are 182 THE HEAD AND NECK [Chap. approximated in speech under the influence of the crico-arytenoideus lateralis. The mucous membrane of the larynx varies in thickness in different parts, and in the amount of its submucous tissue. The membrane is thick- est, and the submucous tissue most abundant, in .the following parts, taken in order of degree : The aryteno-epiglottidean folds, the mucous mem- brane of the ventricle, the false cords, and the laryngeal aspect of the epiglottis. These are the parts that become most congested and swollen in acute laryngitis ; and the serious condition known as oedema of the glottis depends mainly upon effusion into the lax submucous tissue in the aryteno-epiglottidean folds. The lax condition of the mucous membrane of the aryteno-epiglottidean folds allows free movements of the arytenoid cartilages and complete closure of the upper aperture of the larynx (Fig. 42). The mucous membrane is firmly bound to the true vocal cords and covered by stratified epithelium, while the rest of the larynx is lined, like the trachea, with ciliated epithelium. Owing to the nature of its covering and exposure to friction, the true vocal cord is not an uncommon site of epithelioma. The affection known as "clergyman's sore throat" has an interesting anatomical basis. The mucous membrane of the larynx is well provided with mucous glands, whose function it is to keep moist the parts concerned in phonation. When an in- dividual speaks aloud for a t long time the lining of the larynx tends to become dry, on account of the large amount of cold air that is drawn in directly through the mouth. To keep these parts moist the mucous glands have to exhibit increased energy, and in those who speak much in public the glands may in time become so over- worked as to inflame. It is the inflammation of these glands that constitutes the present affec- tion. The glands are not distributed equally over all parts of the larynx, but are most numerous in the membrane covering the arytenoid cartilages IX] EXCISION OF THE LARYNX 183 and parts immediately about them, the base of the epiglottis, and the interior of the ventricle. It is in these parts, therefore, that the changes in chronic glandular laryngitis, or dysphonia clericorum, are most marked. Excision of the larynx. — The entire larynx has been removed for carcinomatous disease, but the operation, although not immediately fatal, has not been followed by very satisfactory results. It is removed through an incision in the middle line. In this incision are divided the platysma, the fascia, and the anterior jugular vein. The larynx is separated from its connexions, the fol- lowing structures being divided : sterno-thyroid, thyro-hyoid, stylo-pharyngeus, palato-pharyngeus, and inferior constrictor muscles, the laryngeal branches of the superior and inferior thyroid arteries, superior and inferior laryngeal nerves, hyo-epiglottic and glosso-epiglottic ligaments. The larynx is then separated from the trachea, and is dissected off from below up. In separating the gullet and pharynx there is great risk of " button- holing " the former tube. Growths and foreign bodies may be removed from the larynx by the operation of thyrotomy : the two alse of the thyroid are separated along the middle line and pulled apart, thus exposing the interior of the larynx. In subjects over 45 years of age the cartilage be- comes ossified in the middle line, and will require division by a fine saw. It should be remembered that the vocal cords are attached on each side of the median line near the mid-point of the anterior border of the thyroid cartilage, while just above them are fixed the false vocal cords and stalk of the epiglottis. The lymphatic vessels of the upper half of the larynx follow the superior laryngeal vessels and pass to the upper deep cervical glands. A small lymphatic gland, the first to become the seat of secondary cancerous # deposit, is situated below the horn of the hyoid on the thyrohyoid mem- brane (Fig. 44, p. 197). The lymphatics of the 184 THE HEAD AND NECK '[Chap. lower half of the larynx accompany the inferior thyroid vessels and pass through lymph glands by the side of the trachea. Tracheotomy and laryngotomy. — The trachea is about 4j inches in length, and from f to 1 inch in its extreme width. It is surrounded by an atmosphere of very lax connective tissue, which allows a considerable degree of mobility to the tube. The mobility of the trachea is greater in children than in adults, and adds much to the difficulties of tracheotomy. In this procedure the windpipe is opened in the middle line by cutting two or three of its rings above, below, or through the isthmus of the thyroid gland. Since the trachea, as it descends, lies farther from the sur- face, and comes in relation with more and more important structures, it is obvious that, other things being equal, the higher in the neck the operation can be done the better. The length of trachea in the neck is not so considerable as might at first appear, and, according to Holden, not more than some seven or eight of the tracheal rings (which number sixteen to twenty in all) are usually to be found above the sternum. The dis- tance between the cricoid cartilage and the sternal notch varies greatly, and depends upon the length of the neck, the age of the patient, and the posi- tion of the head. If 2 inches of trachea are ex- posed above the sternum when the head rests easily upon the spine, then in full extension of the head some | of an inch more of the windpipe will^ as it were, be drawn up into the neck. According to Tillaux, the average full distance between the cricoid cartilage and the sternum is, in the adult, about 2f inches (7 cm.). The full distance in a child between 3 and 5 years is about H inches (4 cm.),^ in a child between 6 and 7 years about 2 inches (5 cm.), and in children between 8 and 10 years about 2| inches (6 cm.). As may be imagined, the dimensions of the trachea on section vary greatly at different ages, and even in different individuals of the same age. This IX] TRACHEOTOMY 185 leads to the question as to the proper diameter of tracheotomy tubes. Guersant, who has paid much attention to this matter, says that the dia- meter of the tubes should run from 6 mm. to 15 mm.* The tubes with a diameter of , from 12 mm. to 15 mm. are for adults. For children under eighteen months the diameter of the tube should be about 4 mm. In performing tracheotomy it is most im- portant that the head be # thrown as far back as possible, and that the chin be kept strictly in a line with the sternal notch, so that the relations of the middle line of the neck be preserved. Full extension of the head not only gives the surgeon increased room for the operation, but also brings the trachea nearer to the surface, and by stretch- ing the tube renders it much less mobile. ^ In cutting down unon the trachea in tKe middle line of the neck from the cricoid cartilage to the sternum the following parts are^ met with : Beneath the integument lie the anterior jugular veins. As a rule these veins lie some little way apart on either side of the median line, and do not communicate except ^ by a large transverse branch which lies in the interfascial space at the upper border of the sternum. Sometimes there are many communicating branches right in front of the tracheotomy district, or the veins may form almost a plexus in front of the trachea, or there may be a single vein which will follow the middle line. Then comes the cervical fascia, enclosing the sterno-hyoid and stern o-thyroid muscles. The gap between the muscles of opposite sides is lozenge-shaped, and is such that the trachea can he, exposed without dividing muscle fibres. The isthmus of the thyroid usually crosses the second, third, and fourth rings of the trachea. Above it a transverse communicating branch be- tween the superior thyroid veins is sometimes found. Over the isthmus is a venous plexus, from * The reader may be reminded that 12 mm. = about h an inch, an 6 mm., therefore, = about £"of an inch. 186 THE HEAD AND NECK [Chap. which the inferior thyroid veins arise, while be- low the isthmus these veins lie in front of the trachea together with the thyroidea ima artery (when it exists). The inferior thyroid vein may be represented by a single trunk occupying the middle line. In the infant before the age of two years the thymus extends up for a variable dis- tance in front of the trachea. At the very root of the neck the trachea is crossed by the innomi- nate and left carotid arteries and by the left innominate vein ; and lastly, abnormal branches of the superior thyroid artery may cross the upper rings of the windpipe. The evil of wounding the thyroid isthmus is greatly exaggerated. I have frequently divided this structure in performing tracheotomy, without any inconvenience resulting. Like other median raphes, the middle line of the thyroid isthmus has but a slight vascularity, and it has been shown that one side of the thyroid gland cannot be in- jected from the other (i.e. by injection that would cross the isthmus). The difficulty of tracheotomy in infants depends upon the shortness of the neck, the amount of the subcutaneous fat, the depth at which the trachea lies, its small size, its great mobility, and the ease with which it can be made to collapse on pressure. To the finger, roughly introduced, the infant's trachea offers little resistance. Its mobility is such that we hear of its being held aside unknowingly by re- tractors while the operator is scoring the oeso- phagus (Durham). In the child, too, the great vessels often cross the trachea higher up than in the adult, and some inconvenience may also arise from an unduly prominent thymus. In one case, in an infant, the end of a tracheotomy tube press- ing on the front of the trachea produced an ulcer that opened the innominate artery (Brit. Med. Journ., 1885). In introducing the cannula, if the tracheal wound be missed, it is easy to thrust the instrument into the lax tissue beneath the cervical fascia and imagine that it is within the windpipe. IX] LARYNGOTOMY 187 In laryngotomy the air-passage is opened by a transverse cut through the crico-thyroid mem- brane. The crico-thyroid space only measures about \ an inch in vertical height in well- developed adult subjects, while in children it is much too small to allow of a cannula being in- troduced. The crico-thyroid arteries cross the space, and can hardly escape division. They are, as a rule, of very insignificant size, and give no trouble. Occasionally, however, these vessels are large, and " cases are recorded in which serious and even fatal haemorrhage has occurred from these vessels" (Durham). . In introducing the cannula it may readily slip between the crico- thyroid membrane and the mucous lining instead of entering the trachea. Foreign bodies often find their way into the air-passages, and they have been represented by articles of food, teeth, pills, buttons, small stones, and the like. They are usually inspired during the act of respiration, and may lodge in the superior aperture of the larynx, or in the rirna, or find their way into the ventricle, or lodge in the trachea, or enter a bronchus. If a foreign substance enters a bronchus it usually selects the right, that bronchus having its aperture more immediately under the centre of the trachea than has the left tube. On one occasion, in a dissecting- room subject, I found two threepenny pieces lying side by side, in the right bronchus, so as en- tirely to block the tube. The danger of inhaled foreign substances depends not so much upon the mechanical obstruction they offer, as upon the spasm of the glottis they excite by reflex irrita- tion. A body may, however, lodge in the ventricle for some time without causing much trouble, as in a case reported bv Desault, where a cherry- stone lodged for two years in this cavity without much inconvenience to its host.^ In one strange case a bronchial gland found its way into the trachea by producing ulceration of that tube, was coughed up, and became impacted in the rima 188 THE HEAD AND NECK [Chap. glottidis. The patient was saved from immediate suffocation by tracheotomy. Thyroid body. — Eachlobe of this body should measure about 2 inches in lengthy l\ inches in breadth, and j of an inch in thickness at its largest part. When distinctly beyond these mea- surements the thyroid ^ may be considered to be enlarged. Its usual weight is between one and two ounces. Of its three surfaces (Fig. 43), the ante- rior is covered by the infrahyoid muscles, its inner Ant. Juq. Vein Tra . che * Sterno-Hyoid Sternothyroid Sterno-Mastoid Juq. Vein Carotid Art. Recurrent Laryng. N. Trachea CEsophagu OMOHYOID Inf. Thyroid Art. Vert. Art. Thyroid Body Fig. 43. — Diagrammatic section to show the relations of the thyroid body. rests on the larynx and trachea, while its outer or posterior^ covers the carotid sheath. Its promi- nent posterior border is in contact at its lower part with the recurrent laryngeal nerve and oesophagus. Each lobe extends from about the middle of the thyroid cartilage to the sixth ring of the trachea. It is larger in females than in males, and the right lobe is usually larger than the left. In connexion with these matters it may be noted that thyroid enlargements (bronchocele, goitre) are more common in females than in males, and in any case are more apt to be first IX THYROID BODY 189 noticed on the right side. The body being closely adherent to the trachea and larynx, it follows that it moves up and down during deglutition, and this circumstance is of the utmost value in the diagnosis of bronchocele from other cervical tumours. A strong process of cervical fascia (the suspensory ligament of Berry) binds the gland to each side of the cricoid cartilage, and has to be severed before complete removal is possible. The thyroid when enlarged may distort and narrow the trachea, and this is all the more likely to be the case when the enlargement occurs rapidly, since the body is held down by the sterno-hyoid, sterno-thyroid, and omo-hyoid muscles. The pos- terior or outer surface of the thyroid body being in contact with the sheath of the great vessels, it follows that the gland when enlarged may readily receive pulsations from those vessels (Fig. 43). It generally touches also the lower part of the pharynx, and the upper part of the gullet behind, and enlargement in this direction may, in connexion with the interference with the move- ment of the larynx in deglutition, serve to ex- plain the difficulty in swallowing often noticed in bronchocele. The isthmus of the thyroid gland is developed from a diverticulum which is protruded from the ventral wall of the pharynx in the embryo between the mandibular and hyoid parts of the tongue (Fig. 45, p. 201). The f foramen caecum of the tongue represents the point at which the diverti- culum grew out from the pharynx. From this foramen a duct (the thyro-glossal) may be found to lead to accessory^ gland masses about the hyoid bone. In the vicinity t of this bone accessory glands and small cysts lined with epithelium are not infrequently met with. These glands, to- gether with the so-called pyramid or middle lobe, are the remains of the neck of the primitive diver- ticulum. Below the level of the hyoid bone the median bud divides ; hence the pyramidal lobe represents the stalk of the right or of the left 100 THE HEAD AND NECK [Chap. division and is never in the median line. The pyramid, which is nearly always connected to the hyoid bone by the levator thyroidese, exists in 79 per cent, of the subjects examined (Streckeisen). The lateral lobes are developed from the fourth visceral clefts (Fig. 45). The median diverticulum occasionally fails to join one of the lateral, in which case the isthmus is partially absent. Small accessory thyroid bodies are frequently present. The parathyroid bodies appear to play an essential part in the function of the thyroid. They are of the size of small peas, and have a structure similar to that of the ^ medulla of the suprarenal bodies, the cells being grouped in reticulating columns. Two are usually found on each side, one behind the lower pole of the lateral lobe,, the other behind the lobe amongst the ter- minal branches of the inferior thyroid artery. Parathyroid bodies become less numerous as age advances, so that in the aged none may be found (Forsyth). The parathyroid bodies may develop vesicles containing colloid material, and thus be- come very similar to small accessory thyroids. Atrophy of the thyroid gland, or its destruc- tion by disease, is apt to lead to a general con- dition of the body known as myxoedema. The condition closely resembles cretinism, especially as met with in goitrous subjects. Myxoedema may follow the entire excision of the gland by opera- tion, and has been produced in monkeys by ex- perimental removal of the same. One prominent feature of myxoedema is the swelling of the sub- cutaneous tissues from an accumulation therein of a mucinoid substance. Vasometer nerves reach the thyroid through the lower part of the cervical sympathetic chain, and by the same course nerves pass upwards to the eye. These nerves appear to be connected cen- trally, probably in the medulla, for in certain conditions enlargement of the thyroid is accom- panied bv protrusion of the eye (exophthalmic goitre). The lymphatics of the thyroid gland are IX] THE (ESOPHAGUS 101 numerous, and pass to the deep cervical and superior mediastinal lymph glands. Asher and Flack found that the internal secretion of the thyroid body could be increased by stimulation of the laryngeal nerves. The superior thyroid artery reaches the gland at the apex of the lateral lobe; the inferior thyroid artery enters the lower part of the lobe at its posterior aspect. In securing this vessel, and in liberating the lower part of the gland during excision, the recurrent laryngeal nerve is in great danger of being damaged. The thyroidea ima artery, an extra vessel to the thyroid body, usually arises from the innominate, and is found in one subject out of every ten. The gullet commences opposite the sixth cervical vertebra, and pierces the diaphragm opposite the tenth dorsal vertebra. The point is marked on the back by the overlapping spine of the ninth dorsal vertebra. By placing the stetho- scope a little to the left of this spine, fluid may be heard to enter the stomach. The gullet pre- sents three curves : one is antero-posterior, and corresponds to the curve of the spinal column ; the other two are lateral. Commencing at the middle line, it deviates slightly to the left as far as the root of the neck; from thence to the fifth dorsal vertebra it gradually returns to the middle line, and finally it turns again to the left, at the same time passing forwards 5 to pierce the diaphragm. Its length is from 9 to 10 inches. There are three narrow parts in the gullet — one at its commence- ment, one about 2| inches from that point, and a third where the tube passes through the dia- phragm. The narrowing at the commencement and termination of the oesophagus is due to the fact that the musculature at these points is sphincteric in nature, and, except during the pas- sage of food, the lumen in these parts is closed. The diameter at each of these points is a little over J an inch (14 mm.) ; the diameter elsewhere is about | of an inch (17 mm. to 21 mm.). By forcible 192 THE HEAD AND NECK [Chap. distension the two upper narrow parts could be distended to a diameter of 18 to 19 mm., the lower part to 25 mm., and the rest of the gullet to a diameter of nearly lj inches (35 mm.). It follows that foreign bodies when swallowed are most apt to lodge either at the commencement of the gullet or at the spot where it passes through the dia- phragm. The same parts also are those most apt to show the effects of corrosives that have been swallowed. Among the relations of the oesophagus, the following may be noted as receiving illustration in surgical practice : The gullet is in nearly all its course in close relation with the front of the vertebral column. In the neck the trachea is immediately in front of it. In the thorax it has the left bronchus, left bronchial glands, pericardium, and left auricle in front of it, while the two vagi form a plexus on it. The left bronchial glands, when enlarged, may press on the gullet, adhere to it, or even cause localized soften- ing and diverticula to spring from it. The thoracic duct passes behind to reach the left side of the gullet in the upper part of the thorax, while in the lower part the aorta, at first to the left of the oesophagus, gradually becomes pos- terior to it. It is, moreover, partly in contact with both pleurae, but more especially with the membrane of the right side ; and, lastly, the recur- rent laryngeal nerve ascends between it and the trachea. (See Figs. 50 and 90, pp. 228 and 435.) Foreign bodies impacted in the gullet are very apt to lead to ulcerations that may open ad- jacent parts. Thus, in the Musee Dupuytren is a specimen showing a five-franc piece which had stuck in the gullet, and had produced an ulcer that had opened the aorta. In another instance a " smasher " swallowed a counterfeit half-crown piece. Eight months afterwards he died of haemorrhage. The coin had sloughed into his aorta. In another case (Lancet, 1871), a fish-bone, lodged in the gullet opposite the fourth dorsal IX] (ESOPHAGEAL MALFORMATIONS 193 vertebra, had caused two perforating ulcers; one on the right side had caused plugging of the vena azygos major, while the other on the left had made a hole in the aorta. Less frequently, impacted foreign substances have found their way into the trachea and into the posterior mediastinum. Dr. Ogle reports a case {Path. Soc. Trans. , vol. iv.) where a piece of bone impacted in the gullet induced ulceration of an intervertebral disc and subsequent disease of the spinal cord. Carcinoma of the gullet, also, when it spreads, is apt to invade adjacent parts, and especially to open into the trachea or bronchi. If it spreads to the pleura, it will usually involve the right pleura, as being the membrane more in relation with the gullet. Cancer of the gullet has so spread as to invade the thyroid body, the pericardium, and the lung, and has opened up the first intercostal artery in one case and the right subclavian in another (Butlin's 4i Sarcoma and Carcinoma," 1882). The sensory nerve supply of the oesophagus comes mainly from the fifth dorsal segment of the cord (Head). In cases of cancer or burns of the gullet, pain is referred to the skin of this seg- ment (see Fig. 70, p. 345). (Esophageal malformations. — In the newly born the upper part of the oesophagus may end blindly, while the lower part commences by an opening in or near the bifurcation of the trachea, so that milk can only reach the stomach by first passing into the larynx and trachea. Death soon follows from suffocation or septic pneumonia. The condition is the result of a maldevelopment of the septum between the trachea and oesophagus. Hernial diverticula of the mucous membrane occasionally occur at the junction of the oesopha- gus and pharynx, immediately above the upper sphincter of the oesophagus. They are named pharyngeal pouches, and protrude between the lower border of the inferior constrictor and commencement of the oesophageal musculature, H 194 THE HEAD AND NECK [Chap. opposite the cricoid cartilage. Since the pouch lies against the spine, it necessarily compresses the commencement of the oesophagus when it becomes filled with food. The operation of oesophagotomy consists in incising the gullet for the purpose of removing an impacted foreign body. The gullet is usually reached from the left side, since it projects more on that aspect. The incision is made between the sterno-mastoid and the trachea, in the same direc- tion as the incision for ligaturing the common carotid. The cut extends from the top of the thyroid cartilage to the sterno-clavicular joint. The omo-hyoid muscle is drawn outwards, or cut. The great vessels, larynx, and thyroid gland are drawn aside, and care must be taken not to wound these structures nor damage the thyroid vessels, thoracic duct, or the recurrent nerve. The gullet, when exposed, is opened by a vertical incision. Oreat vessels. — The course, relations, and abnormalities of the great cervical vessels, to- gether with the operations whereby they may be ligatured, and the details pertaining to those procedures, are so fully given, not only in works on operative surgery, but also in the chief ana- tomical text-books, that nothing need be said upon the matter in this place. The main relationships of. the carotid and subclavian arteries are shown in Fig. 39, p. 168. In Brasdor's operation a main trunk is ligatured on the distal side of an aneurysm, no t branches intervening between the sac and the ligature. The cure by this measure depends upon the fact that blood does not con- tinue to go to parts when once the need for blood in them is diminished. Thus, after amputation at the hip-joint, the femoral artery, having no need to carry to the stump the amount of blood it brought to the limb, often shrinks to a vessel no larger than the radial. W nen an aneurysm low down in the carotid artery is treated by ligature of the vessel near its bifurcation by Brasdor's method, the blood, having now, as it were, no IX] VESSELS OF THE NECK 195 object in entering the carotid trunk, soon ceases to fill the vessel entirely, and the artery (and in successful cases the aneurysm) shrinks in con- sequence. The right carotid and subclavian have also been ligatured for aortic aneurysm with some success, and here also the reason for the good effected by the operation is difficult to appreciate. It has been pointed out that the innominate artery lies more or less directly in the axis of the ascend- ing aorta, while the left carotid and subclavian arteries arise at an angle to that axis, and it is upon this fact that reasons have been founded for selecting the vessels of the right side (Barwell). The matter is, however, complicated by the know- ledge that when vegetations are swept off the aortic valves they enter the left carotid with in- finitely greater frequency than they do the right. The whole subject, indeed, requires investigation. The cervical connective tissue being lax, aneu- rysms in this part can grow and spread rapidly, and usually soon produce " pressure symptoms." As examples of these may be noted oedema and lividity of the face and of the upper limb from pressure upon the main veins, laryngeal symptoms from pressure upon the recurrent nerve or trachea, spasm of the diaphragm from pressure upon the phrenic nerve, damage to the sympathetic, and giddiness and impaired vision from anaemia of the brain. The vertebral artery has been ligatured with doubtful benefit in cases of epilepsy. It is sur- rounded by vasomotor nerves derived from the inferior cervical ganglion, which also are neces- sarily tied. The artery is reached through an in- cision made along the posterior border of the sterno-mastoid muscle just above the clavicle. The " carotid tubercle" (see Fig. 39, p. 168) is then sought for, and vertically below it lies the artery, in the gap^ between the scalenus anticus and longus colli muscles. The procedure is sur- rounded with considerable difficulties. Air in veins,— The veins of the neck are under 196 THE HEAD AND NECK [Chap. the influence of the respiratory movements. The veins do not collapse owing to attachments to the surrounding fascise. During inspiration these vessels become more or less emptied ; during ex- piration they become enlarged and turgid. ^ With greatly impeded breathing they may attain for- midable size. Since ether usually causes some respiratory difficulty, it is seldom administered in operations on the neck. The only other veins that are under the influence of the aspiratory power of the thorax are the axillary vein and its larger tributaries. When any one of these vessels is wounded, and the wound is for the moment dry, air may very readily be drawn into it during the inspiratory act, just as air is drawn into the trachea. The air causes embolism of the pulmonary capillaries. Valves in the veins of the neck. — The subclavian veins and their tributaries are liberally pro- vided with valves, but the internal jugular has only one pair, situated at its termination in the innominate vein. There are no valves in the innominate veins or in the superior vena cava. When the venous pressure within the thorax is greatly raised, as in lifting heavy weights, only the terminal valves of the internal jugular vein prevent the transmission of the pressure to the brain. In accidents which cause sudden compres- sion of the thorax, the head and neck may remain livid for days following the accident. The lividity is probably due to the jugular valves yielding, thus subjecting the capillaries of the head and neck to a higher pressure than they are able to withstand. The lymphatic glands of the head and neck are numerous, and arranged in the follow- ing sets (Fig. 44) : — (1) Submaxillary glands, 10 to 15 in number, situated at the lower border of the jaw beneath the cervical fascia ; (2) the suprahyoid, 1 or 2 in number, situated between the chin and hyoid bone near the middle line; (3) parotid or pre- IX LYMPHATIC GLANDS ■197 Fig. 44. — Showing the position of the lymphatic glands of the head and neck. The outlines of the sterno- mastoid (S.M.), trapezius (TR.), internal jugular, subclavian, and right innominate veins are shown. 1, Submaxillary glands, 1' area drained ; 2, suprahyoid glands, 2' area drained : 3, parotid glands, 3' area drained ; 4, postauricular glands, 4' area drained ; 5, occipital glands, 5' area drained ; 6, in front of external jugular vein, marking position of the superficial cervical glands ; 7, laryngeal gland ; 8, 8, 8, upper deep cervical glands ; 9, 9, 9, lower deep cervical glands ; 10, gland receiving lymph from thyroid ; 11, superior mediastinal glands j 12, axillary glands. 198 THE HEAD AND NECK LChap. auricular set, situated in and over the parotid gland; (4) postauricular or mastoid, 2 to 4 in number, situated over the mastoid process; (5) occipital, 3 to 5 in number, over the insertion of the complexus muscle; (6) superficial cervical glands, often absent, situated over the sterno- mastoid along the external jugular vein; (7) laryngeal, 1 to 3 in number, below the great horn of the hyoid ; (8) the upper deep cervical set, 10 to 20 in number, situated over the upper part of the internal jugular vein and bifurcation of the common carotid artery ; (9) lower deep cervical set, surrounding the terminal parts of the in- ternal jugular, subclavian, external jugular, and transverse cervical veins. This set becomes con- tinuous with the axillary and mediastinal glands. These glands are very often enlarged and in- flamed, and it is in this part of the lymphatic system that the changes in scrofula are most com- monly met with. The inflammatory affections in glands would appear to be always of a secondary nature (if we exclude some cases of inflammation incited by injury, and perhaps by exposure to severe cold), and to follow disturbances in those parts of the periphery whence they respectively receive their lymph. It may be convenient, there- fore, to group the relations of certain glands to certain parts of the periphery. Scalp. — Posterior part = occipital and post- auricular glands. Frontal and parietal portions = parotid glands (Fig. 44). Vessels from the scalp also enter the super- ficial cervical set of glands. Skin of face and neck = submaxillary, parotid, and superficial cervical glands. External ear = superficial cervical glands. Lotver lip = submaxillary and suprahyoid glands. Buccal cavity = submaxillary glands and deep cervical glands (upper set). Gums of lower jaw = submaxillary glands. Tongue. — Anterior portion = suprahyoid and IX] LYMPH-GLANDS 109 submaxillary glands. Posterior portion = deep cervical glands (upper set). Tonsils and palate = deep cervical glands (upper set). Pharynx. — Upper part = parotid and retro- pharyngeal glands. Lower part = deep cervical glands (upper set). Larynx, orbit, and roof of mouth = deep cer- vical glands (upper set). Nasal fossce = retropharyngeal glands, deep cervical glands (upper set). Some lymphatics from the posterior part of the fossae enter the parotid glands.* In the removal of the deep cervical glands a number of structures are liable to be wounded. The glands frequently become firmly adherent to the internal jugular vein; the uppermost glands surround the spinal accessory nerve; the super- ficial cervical nerves pass among those of the lower deep cervical set ; the thoracic duct has been wounded in removing glands from the left supra- clavicular fossa. Thoracic duct in the neck. — A point taken on the upper border of the clavicle, 1 inch from its sternal end, will mark the angle between the internal jugular and subclavian veins at or near which the thoracic duct ends. In forty bodies investigated by Messrs. F. G. Parsons and P. W. G. Sargent the duct was found to end in the ter- minal part of the internal jugular vein in thirty- five instances ; in nearly half of these cases the terminal part of the duct divided; it frequently has two orifices, and may have as many as four. At its termination the duct curves outwards over the scalenus anticus and phrenic nerve above its point of entrance where it is usually furnished with valves. Ligature of the duct is followed by no untoward symptoms, as a rule, a result which is due to the free anastomosis which exists between it and the lymphatics of the right side * From "Scrofula, and its Gland Diseases," by the Author. 200 THE HEAD AND NECK [Chap of the thorax and to communications with the azygos veins (Leaf). As the duct ascends behind the left common carotid and subclavian arteries to enter the neck, it lies in contact with the pleura and lung. On the rigbt side the thoracic duct is represented by the right lymphatic trunk. The tributaries of these two main lymphatic channels are in free communication within the thorax. Branchial fistula*. — Certain congenital fis- tulae are sometimes met with in the neck, which are due to partial persistence of one of the branchial clefts. These clefts are placed in the foetus between the branchial arches. The arches are usually described as five in number. The first lays the foundation for the lower jaw and malleus. From the second are developed the sty- loid process, the stylo-hyoid ligament, and lesser cornu of the hyoid bone. From the third are formed the body and greater cornu of the hyoid bone, while the fourth and fifth take part in the formation of the soft parts of the neck below the hyoid bone. The first cleft is between the first and second arches. "The cervical branchial fistulse appear as very fine canals opening into minute orifices in one or both sides of the fore part of the neck and leading backwards and inwards or backwards and upwards towards the pharynx or oesophagus " (Paget). Their length is about lj to 2j inches, and their diameter varies from that of a bristle to that of an ordinary probe. The orifice of a cervical fistula is usually situated just above the sterno-clavicular joint (Fig. 45), and represents the orifice of the cervical sinus, a depression or pocket formed during the develop- ment of the neck of the foetus, and serving as a common orifice for the visceral clefts in which the tonsil, thymus and lateral thyroids are developed (Fie:. 45). The fistula passes towards the bifur- cation of the^ common carotid, where it may come into communication with the carotid bodv (derived from the third cleft), or with the tonsillar recess IX] BEANCHIA"L FISTULiE 201 (from the second cleft). It can be understood that only parts of these saccular structures and outgrowths may persist, such remnants forming the basis for cervical cysts. Certain dermoid cysts Fig. 45. — Diagram to show the position and connexions of various embryological remnants in the neck. (Br. S. J. A. Beale.) A, Tonsil ; B, remnant of tonsillar sac (from second cleft recess) ; C, carotid body between external and internal carotid arteries ; D, stalk of thymus (3rd cleft) ; e, cervical sinus (united with 2nd cleft recess on left side) ; F, cervical thymus ; G, common carotid, G' median part of thyroid and thyro-glossal duct ; H, infrahyoid part of median thyroid ; I, stalk of lateral thyroid from 4th cleft ; K K, thymus in thorax, 202 THE HEAD AND NECK [Chap. IX of the neck, and also certain polycystic congenital tumours, occurring as one form of " hydrocele of the neck," also arise from these branchial remnants. At the orifice of the fistulse, or at the position where they usually occur, tags of skin containing cartilage may appear. They are termed supernumerary auricles, because they occupy the same relationship to the fistulse that the external ear does to the first visceral cleft. # The ventricle of the larynx, as is normally the case in many apes, may become prolonged into a sac which passes into the neck through the thyro- hyoid membrane, thus forming a cervical air cyst or sac. Part IL— THE THORAX CHAPTER X THE CHEST AND ITS VISCERA The Thoracic Walls The two sides of the chest are seldom sym- metrical, the circumference of the right side being usually the greater, a fact that is supposed to be explained by the unequal use of the upper limbs. In Pott's disease, involving the dorsal region, when the spine is much bent forwards the thorax becomes greatly deformed. Its antero- posterior diameter is increased, the sternum protrudes, and may even be bent by the bending of the spine, the ribs are crushed together, and the body may be so shortened that the lower ribs overlap the iliac crest. In pigeon breast deformity the sternum and cartilages are rendered protuberant, so that the antero-posterior measurement of the chest is much increased, while a deep sulcus exists on either side along the line of junction of the ribs and their cartilages. It is by the sinking-in of the parietes along the costo-chondral junctions that the protuberance is produced. In children, and especially in rickety children, the thorax is very pliable and elastic, and if a constant impediment exists to the entrance of air, as afforded, for 203 204 THE THORAX [Chap. example, by greatly enlarged tonsils, the thoracic walls may yield in time to the suction brought to bear upon them at each^ inspiration. The weakest part of the thorax is along the costo- chondral line on either side, and it is here that the parietes yield most conspicuously in such cases, and by this yielding the deformity is pro- duced. Deformities of the ehest result from abnor- mal curvatures of the dorsal part of the spinal column. The ribs are firmly bound to the verte- brae by the costo-vertebral and costo-transverse ligaments, and hence alteration in the position of vertebrae is attended by^ changes in the costal series. Thus, when there is kyphosis in the dorsal region the upper part of the spine is bent for- wards and downwards, carrying with it the upper ribs and the sternum. The antero-posterior diameter of the thorax is thereby increased, but its vertical and transverse measurements are de- creased. When lateral curvature is produced in the dorsal region, the ribs, on the side towards which the bend occurs, are necessarily compressed, while on the opposite side they are separated. In scoliosis of the spine not only is a lateral curva- ture formed, but the vertebrae undergo a rotation at the same time. The vertebral bodies move to- wards the convexity and their spines towards the concavity of the curvature (Fig. 46). The ribs on the concave side are carried forwards on the traps- verse processes and their angles open out, the side of the chest becoming flattened behind. On the other side (convex) the angles are unduly promi- nent, for the ribs are carried backwards at their vertebral extremities and bent inwards in front. The transverse diameter of the chest thus becomes oblique (Fig. 46). On the concave side the inter- costal spaces are diminished in size, the ribs even coming into contact, while on the convex side the spaces are increased in size. The thoracic viscera are necessarily distorted in shape and altered in position, X] FRACTURES OF THE STERNUM 205 The sternum.— -The upper edge of the sternum corresponds to the disc between the second and third dorsal vertebrae, and the ster no-xiphoid joint to the middle of the tenth dorsal. In the foetus at full term the upper edge of the sternum is opposite the middle of the first dorsal vertebra (Symington). A transverse ridge may be felt upon its anterior surface that corresponds to the junction of the manubrium and gladiolus, and is in a line with the second costal cartilages. The skin over the sternal region is the part of the surface most fre- quently the seat of cheloid. The bone is rarely fractured, being Fig. 46.- Showing the changes in the sort ana spongy, thorax which f n ow scoliosis of and supported by the spIne . (After Retard.) the elastic ribs mw , ,, . . j f i • „ QT ..|.ii Tne convexity of the spinal curvature is cinu tneir cartll- towards the right ; on that side the ribs ages, as by a are sharply bent at their angles. On the series of springs concave (left) side the ribs have an open In the old, when the cartilages are ossified and the chest is more rigid, the tendency to fracture is increased. The sternum is most often found fractured in connexion with injuries to the spine, although it may be broken by simple direct violence. The bone may be fractured by violent bending of the spine back- wards, and by abrupt bending of it forwards. In the former instance the lesion is probably due to muscular violence, to the abdominal muscles and the sterno-mastoid pulling one against the other. In the latter instance the lesion is commonly brought about by the violent contact of the chin with the bone. Dislocation may occur at the sterno-manubrial joint. The manubrium in these injuries generally remains in situ, while the 206 THE THOHAX Chap. gladiolus with the ribs is displaced forwards in front of it. A considerable degree of respiratory movement takes place at this joint; only in very old people does it become obliterated by bony union. It possesses a distinct synovial cavity surrounded by strong fibrous and fibro-cartilagin- ous ligaments. Malgaigne cites the case of a youth who, from constant bending at his work as a watchmaker, caused the second piece of the sternum to glide backwards behind the manu- brium. From its exposed position and cancellous struc- ture, the sternum is liable to many affections, such as caries and gummatous periostitis. The com- parative softness also of the bone is such that it has been penetrated by a knife in homicidal wounds. The shape and position of the bone have also been altered by pressure, as seen sometimes in artisans following employments requiring in- struments, etc., to be pressed against the chest. Certain holes may appear in the middle of the sternum, and through them mediastinal abscesses may escape, and surface abscesses pass deeply into the thorax. These holes result from imperfect union of the right and left sternal bars, out of which the sternum is formed. In the case of E. Groux, the bone was separated vertically into two parts. The gap could be opened by muscular effort and the heart exposed, covered only by the soft parts. The sternum has been trephined for mediastinal abscess, and for paracentesis in peri- cardial effusion, and it has been proposed also to ligature the innominate artery through a trephine hole in the upper part of the bone. The ribs are placed so obliquely that the an- terior end of one rib is on a level with the pos- terior end of a rib some way below it in numerical order. Thus the second rib in front corresponds to the fifth rib behind, and the insertion of the seventh to the tenth. If a horizontal line be drawn round the body at the level of the inferior angle of the scapula, while the arms are at the X] THE RIBS 207 side, the line would cut the sternum in front at the attachment of the sixth cartilage, would cut the fifth rib at the nipple line, and the ninth rib at the vertebral column. The second rib is indi- cated by the transverse ridge on the sternum already alluded to (angulus Ludovici). The lower border of the pectoralis major leads to the fifth rib, and the first visible serration of the serratus magnus corresponds to the sixth. The longest rib is the seventh, the shortest the first. The most oblique rib is the ninth. The ribs are elastic and much curved, and, being attached by many ligaments behind to the column, and in front to the yielding cartilages, resist injuries tending to produce fracture with the qualities possessed by a spring. A rib may be fractured by indirect violence, as by a wheel passing over the body when lying prostrate on the back. In such a case the force tends to approxi- mate the two ends of the bone, and to increase its curve. When it breaks, therefore, it breaks at the summit of its principal curve, i.e. about the centre of the bone. The fragments fracture out- wards, and the pleura stands no risk of being penetrated. When the rib is broken by direct violence, lesion occurs at the spot encountered by the force, the bone fractures inwards, the curve of the rib tends to be diminished rather than increased, and there is much risk of the fragments lacerating the pleura. Those most often broken are the sixth, seventh, and eighth, they being under ordinary circum- stances the most exposed. The rib least frequently fractured is the first, which lies under cover of the clavicle. In elderly people dying from phthisis the cartilage of the first rib is often found to be cal- cified and occasionally to be fractured. Fractures are more common in the elderly than in children, owing to the ossification of the cartilages that takes place in advancing life. When a rib is fractured, no shortening occurs, the bone being fixed both in front and behind, while vertical 208 THE THORAX [Chap. displacement is prevented by the attachments of the intercostal muscles. Thus no obvious de- formity is produced unless a number of consecu- tive ribs are the subjects of fracture. These bones have been broken by muscular violence, as during coughing, and in violent expulsive efforts such as are incident to labour. In such instances the ribs are probably weakened by atrophy or disease. In rickets changes take place at the point of junction of the ribs and cartilages leading to bony elevations, which produce, when the ribs on both sides are affected, the condition known as the -? rickety rosary." The intercostal spaces are wider in front than behind, and between the upper than the lower ribs. The widest of the spaces is the third, then the second, then the first. The seventh, eighth, ninth, and tenth interspaces are very nar- row in front of the angles of the ribs. The first five spaces are wide enough to admit the whole breadth of the index finger. The spaces are widened in inspiration, narrowed in expiration, and can be increased in width by bending the body over to the opposite side. Paracentesis is usually performed in the sixth or seventh space, at a point # midway between the sternum and the spine, or midway between the anterior and posterior axillary lines. The seventh space can be readily identified by its relation- ship to the angle of the scapula; when the arm is by the side of the body this space is slightly over- lapped by the angle. If a lower space be selected there is danger of wounding the diaphragm, especially upon the right side. ^ If the eighth or ninth space be selected the incision is made just externally to the line of the angle of the scapula. The trocar should be entered during inspiration, the space being widened thereby, and should be kept as near as possible to the lower border of the space, so as to avoid the intercostal vessels. Tap- ping of the chest through any space posterior to the angles of the ribs is not practicable, owing X] . PARACENTESIS 209 to the thick covering of muscles upon the thoracic wall in this place, and the fact that the inter- costal artery, having a more horizontal course than the corresponding ribs, crosses the middle of this part of the space obliquely. Beyond the angle the intercostal vessels lie in a groove on the inferior border of the rib forming the upper boundary of the space. The vein lies immediately above the artery, and the nerve immediately below it. In the upper four or five spaces, however, the nerve is at first higher than the artery. Paracen- tesis of the thorax is occasionally followed by syn- cope or even death. It is difficult to account for such a result; it may be a reflex inhibition of the heart set up during perforation of the parietal pleura, which is richly supplied by the intercostal nerves, or by injury to the lung, which is supplied by the vagus. Pus may readily be conducted along the loose tissue between the two layers of intercostal mus- cles. Thus, in suppuration following upon disease of the vertebrae, or of the posterior parts of the ribs, the pus may be conducted along the inter- costal spaces to the sternum, and may thus pre- sent at a considerable distance from the real seat of the disease. Removal of ribs.— In order to obtain a free opening into the pleural cavity a portion of one or even two ribs may be excised. In some cases of long-standing empyema with an open sinus, all that part of the bony wall of the thorax which corresponds to the outer boundary of the suppurating cavity is removed in order that the cavity may collapse and be in a position to close. This latter measure is known as Estlander's operation, or thoracoplasty. In some instances portions of as many as nine ribs have been ex- cised, and the total length of bone removed has reached 50 to 60 inches. In removing a rib the bone is entirely bared of periosteum with the rugine, and the excision is extraperiosteal. In this way the intercostal 210 THE THORAX [Chap. vessels are not exposed, and, if divided subse- quently, can be readily secured when the ribs are out of the way. The internal mammary artery runs paral- lel to the border of the sternum, and about \ an inch from it. It may give rise to rapidly fatal haemorrhage if wounded. The vessel may readily be secured in the first three intercostal spaces, and with some difficulty in the fourth or fifth space. It is most easily reached through the second space, and cannot be secured through any space below the fifth. The female breast extends from the second rib above to the sixth below, and from the side of the sternum to the midaxillary line (Stiles). In cases of retained lactation the twelve to fifteen irregular lobes which make up the body of the gland can be felt radiating outwards from the nipple. The lactiferous ducts, which correspond in number to the lobes, open at the apex of the nipple, within which each shows a dilatation or ampulla. Branching processes of adjoining lobes unite and enclose spaces within the body of the gland, containing connective tissue and masses of fat. After the menopause, when the glandular tissue is absorbed in great part, and during the resting condition, fat forms the greater part of the female breast. Besides the main body of the gland, Stiles has drawn attention to numerous peripheral processes which lie in the surrounding connective tissue Although the principal part of the breast rests on the pectoralis major, quite one-third of the gland crosses the outer border and rests on the serratus^ magnus within the axilla. It also covers the origins of the obliquus abdominis externus and rectus abdominis. In excision or inflammation of the breast it is important to bind the arm by the side to keep the parts from being disturbed by the pectoralis major. Peripheral processes of the gland and many of its deep lymphatics enter the pectoral sheath, hence the removal of this XJ THE MAMMA 211 structure with part, or even all, of the pectoral musculature if complete extirpation of cancer is to be assured. The loose retromammary tissue which binds the mamma loosely to the pectoral sheath may be the seat of abscess, or sometimes of a bursal cyst. The nipple, in the male and in the virgin female, is situated on the fourth intercostal space, about | of an inch from the junction of the ribs with their cartilages ; after lactation the breast becomes pendent, and the nipple no longer serves as a guide to the intercostal spaces. The nipple contains erectile and muscular tissue, and is richly supplied by cutaneous branches of the third and fourth spinal nerves. The skin is pigmented, thin and sensitive, and often the seat of painful fissures and excoriations. In painful diseases of the breast, tender areas occur over the fourth and fifth spinal segments (Fig. 70, p. 345) (Head). The breast is developed by a solid invagination of epiblast at the point afterwards marked by the nipple. About the sixth month of total life the primitive mammary bud branches out in all directions within the subcutaneous tissue. Thus it comes about that the subcutaneous fascia is con- densed around the gland, forming its capsule. The retromammary part of the capsule is connected at the interlobular spaces with the superficial layer, which in turn is fixed to the skin by subcutaneous bands, or skin ligaments. It is through lymph channels that cancer spreads, and those of the breast, which is one of the commonest sites of cancer, are of especial im- portance if complete eradication of the disease is to be obtained. The lymph-vessels are arranged inthe following sets: (1) Perilobular, round the acini and lobules; (2) periductal, round the lac- tiferous ducts; (3) interlobar, situated in the interlobar septa and joining (4) the retromam- mary network with (5) the superficial mammary in the anterior part of the capsule. If the inter- lobar septa are invaded by cancer they contract, 212 THE THORAX [Chap. and through their cutaneous attachments cause depressions in the skin ; if the process invades the periductal vessels, the nipple is retracted. The mammary lymphatic system is connected with the subcutaneous network of vessels, to which cancer may spread, producing that variety of the disease known as cancer en cuirasse. Through communi- cations with the lymph channels of the pectoral fascia and muscle, cancer of the breast may spread to these structures. The gland then becomes firmly fixed to the deeply seated structures. The majority of the lymph-vessels pass from the breast to the pectoral glands, six to eight in number, situated along the anterior border of the axilla, and to the central axillary set, twelve to fifteen in number, situated beneath the axillary tuft of hair and on the inner side of the axillary vein. From these two sets the lymph-vessels pass to the deep axillary glands lying along the front and inner side of the axillary vessels. The deep axil- lary glands become continuous with the lower deep cervical glands. It is mainly along this path that cancer tends to spread, but vessels leave the inner segment of the breast and pass to the anterior intercostal glands situated in the upper four intercostal spaces and lying on each side of the internal mammary vessels, while occasionally a few vessels pass to the cephalic gland situated in the hiatus between the deltoid and pectoralis major muscles. Handley found a marked ten- dency for breast cancer to spread downwards in the lymphatics, passing to the epigastric triangle. There the vessels perforate the belly wall to join lymphatics both above and below the diaphragm ; it is probably owing to this communication that the liver is so often the seat of secondary deposit in cases of cancer of the breast. When the normal channels become clogged with cancerous invasion, the lymph passes by circuitous paths. The sub- scapular glands, surrounding the subscapular vessels on the posterior wall of the axilla, may become infiltrated; through the lymphatics of the X] THE MAMMA 213 arm, which end in the central axillary glands, the structures round the shoulder may become the seats of secondary deposit, and through the com- munication between the lymph system of one breast with that of the other, across the sternum, a secondary deposit may even occur in the oppo- site breast (Stiles). The intercosto-humeral nerve pierces the cen- tral set of axillary glands. It becomes compressed when these glands are invaded by cancer, and pain is referred to the termination of the nerve over the posterior aspect of the arm above the elbow. Various parts of the brachial plexus may also become involved or the axillary vein or lym- phatics occluded, the arm being swollen and oedematous in consequence. The following groups of arteries supply the gland and are cut in excision of the organ : (1) the long thoracic, alar thoracic, thoracic oranches of the acromio-thoracic axis; (2) anterior perfor- ating branches from the internal mammary at the second, third, and fourth intercostal spaces; (3) lateral branches from the second, third, and fourth intercostal arteries. Supernumerary nipples and breasts may occur. They are commonly found in a line between the axilla and the groin. In the embryonic stage of all mammals an epiblastic mammary ridge is found in this position. In man it disappears except at one point, but occasionally some isolated part may persist and proceed to form a breast. Embryology fails to explain the occurrence of breasts on the buttock or back, where they are occasionally found. The Thoracic Viscera The lung.— The apex of the lung rises in the neck from 1 to lj inches above the inner half of the clavicle. Its highest point in the majority of adults lies lj inches above the sternal end of the clavicle, in the interval between the sternal 214 THE THORAX [Chap. and clavicular heads of the sterno-mastoid muscle (Fig. 47). The anterior edges of the two lungs pass behind the sternoclavicular articulations, and meet in the middle line at the junction of the manubrium with the gladiolus. The edge of the right lung then continues vertically downwards behind the middle line of the sternum to the sixth Pulmonary Apex Claviclc- Pleural Li/ne .Stereo- /"lANUB.Poim /Iipple Uncovered Area Ster/io- E/xsifor/i Powr Apex Point Pulmonary Line Pleural Line 2" Fig. 47. — Diagram showing surface markings for the lungs and pleura. chondro-sternal articulation, where it slopes off along the line of the sixth cartilage. The edge of the left lung keeps close to that of the right as far as the fourth chondro-sternal articulation, where it turns off to the left, following a line drawn from the fourth cartilage to near the apex of the heart (Fig. 47). Occasionally it does not diverge, but completely covers the pericardium up to the edge of the sternum. In the child, owing to the X] THE LUNG 215 thymus, the lungs are more separated in front. The right reaches the middle line, but the left only reaches the left edge of the sternum (Symington). The easiest and also the most accurate method of indicating the lower border of the lung is the fol- lowing (tig. 47) : A line is drawn along the sixth costal cartnagre from its sternal end to its heel ; from the heel the line is carried horizontally round the body ; it will be found to cross the median line behind, at, or near the eleventh dorsal spine (the anticlinal spine). The corresponding border of the pleura is not parallel to the lower border of the lung ; it is indicated by a line drawn along the seventh costal cartilage from its sternal end to its heel ; from there the line is continued to a point 2 inches above the lowest part of the subcostal margin and then prolonged horizontally to the median line behind where it crosses at or near the twelfth dorsal spine. Between the pul- monary line above and the pleural line below, the diaphragm is in contact with the chest wall, separ- ated only by the costo-phrenic reflection of the pleura. On the left side these lines commence at a variable distance from the sternum — 1 inch should be allowed for the pleura ; 2j inches for the lung (Fig. 47). The pleura is in relation with the twelfth rib, but occasionally it descends \ an inch or more below the neck of this rib, and may be wounded in operations on the kidney (Fig. 90, p. 435). It extends lower down in the child than in the adult. The left lung descends to a slightly lower level than the right. In penetrating wounds involving the pleura, air may enter the pleural cavity, producing pneumothorax, and this air may be subsequently pressed by the respiratory movements into the subcutaneous tissues through the wound in the parietal pleura, and lead to surgical emphysema. In wounds of the lung without external wound, as when that organ is torn by a fractured rib, the air escapes from the lung into the pleura, and may thence pass into the subcutaneous tissues 216 THE THORAX [Chap. through the pleural wound, thus producing both pneumothorax and emphysema. It is well to note that emphysema may occur about certain non=penetrating wounds of the thorax when they are of a valvular nature. In such cases the air is drawn into the subcutaneous tissues during one respiratory movement, and is forced by another into the cellular tissue, the val- vular nature of the wound preventing its escape externally. When the pleural " cavity " is^ opened, the lungs, owing to the amount of elastic tissue they contain, undergo some degree of collapse, but there is much misconception regarding the extent to which this takes place. Half the air in the lung, in some cases even two-thirds, is residual and cannot be expelled by the passive collapse of the lung; when the diaphragm is pushed up and the ribs are pulled down by the expiratory efforts of the muscles of the belly wall the thoracic space may be so reduced in size that the lung still more than fills it ; if the glottis be closed a hernia of the lung will occur through the wound in the chest wall. If, however, there is a valvular orifice into the pleural cavity, so that air can be sucked in but not expelled from it, every respiratory effort increases the amount of air in the pleural space ; then compression of the lung and suffo- cation quickly ensue. Air or fluid introduced within the healthy # pleural cavity is rapidly absorbed. Macewen is of opinion^ that collapse of the lung is prevented bv the capillary attraction which exists between the visceral and parietal layers of the pleura. In wounds of the lung the blood may escape in three directions : into the tissue of the organ ('pulmonary apoplexy), into the bronchi (causing haemoptysis), and into the pleura (causing hsemo- thorax). In some instances the lung has been rup- tured without wound and without fracture to the ribs. These cases are difficult to interpret, and probably the best explanation suggested is that put forward by M. Gosselin. This surgeon be- X] NERVE SUPPLY OF THE PLEURA 211 lieves that at the time of the injury the lungs are suddenly filled and distended with air by a full inspiration, and that the air, prevented from escaping by occlusion of the larynx, thus becomes pent up in the pulmonary tissue, and the lung not being able to recede from the superincumbent pres- sure, its structure necessarily gives way. Owing to the fineness of its capillaries, and to the fact that all venous blood returned to the heart must pass through the lungs before it can reach other parts of the body, it follows that pysemic and other secondary deposits are more commonly met with in the lung than in any other of the viscera. Lung cavities resulting from tuberculosis, gan- grene, or bronchiectasis have been successfully incised and drained, and the same measure has been applied to hydatid cysts of the lung. Deep incisions in the lung are followed by less haemor- rhage than might be expected from such a vascular organ. Nerve supply of the pleura. — In acute inflam- mation of the pleura, pain may be very intense, and the respiratory movements on the side affected may be greatly diminished The pain, if in the lower part of the thorax, may be referred to the abdomen. The explanation of these facts must be sought in the nerve supply of the pleura. The costal pleura is supplied by the adjacent inter- costal nerves, which also supply the corresponding intercostal muscles. The muscles are inhibited when the underlying parts of the pleura are in- flamed. The lower six dorsal nerves also supply the abdominal wall ; hence pain arising in the costal pleura may be referred by the patient to the abdomen, and lead to a suspicion of abdominal disease. The diaphragmatic and the mediastinal pleura are supplied by the phrenic nerves, and pain arising in these parts may be referred to the neck or shoulder. The cervical pleura is also supplied by the phrenic nerve (H. M. Johnston). The trachea divides opposite the junction of 218 THE THORAX [Chap. the manubrium and gladiolus in front, and the fourth dorsal vertebra behind. Certain foreign substances that have been drawn into the air-passages have shown a remarkable facility for escaping through the parietes. Thus Mr. Godlee records the case of a child, from an abscess in whose back there escaped a head of rye-grass that had found its way into the air pas- sages forty-three days previously. Foreign bodies in the trachea and bronchi can now be located and extracted by aid of the bronchoscope. The mucous membrane at the bi- furcation of the trachea is highly sensitive, and the orifices of the secondary bronchial tubes can be seen to contract and dilate by virtue of the circular musculature in their wails. The root of the lung and bronchi can be ex- posed by opening the dorsal wall of the thorax behind the vertebral border of the scapula. Rus- sell and Fox record the case of a boy in whom a pin, 3 inches long, had slipped head downwards within the trachea, and ultimately lodged in the lower division of the left bronchus. They resected part of the eighth rib from the back, pushed the lung forwards to expose the bronchus at the root, and removed the pin. The root of the lung re- quires to be steadied; through the pericardium it is intimately bound to the diaphragm and follows the movements of that muscle. In the case men- tioned above, the boy was able to leave the hospital twelve days after the operation. The heart and pericardium.— The position and extent of the pericardium may be indicated thus on the surface of the thorax (Fig. 48) : Three points are taken : (1) the apical, over the apex beat, in the fifth left intercostal space, 3j inches from the sternum ; (2) the sterno-manubrial, mid- way between the insertions of the second costal cartilages ; (3) the inferior caval, 1 inch to the right of the sterno-ensiform point and directly superficial to the termination of the inferior vena cava. When these three points are united by THE PEMCAEDIUM 210 curved lines, as in Fig. 48, the area over the peri- cardium and its contents is marked out. The lower line crosses \ an inch or more below the sterno-ensiform point; if a trocar be thrust back- wards in the angle between the ensiform process and seventh left costal cartilage, it enters the pericardium just above the diaphragm. Through Right Int.Juculac Vein Right Subclavian Ve Right Innom-Vein St e Rio - /*1an uB. Poi/t Superior VenaCa* Pericardium Right Auricle Auriculc -Ventricular qaoov Dome. StERNOEnSiFOBN LINE- Inferior Caval Point JTERN0- ENSiFORH POlN" Inferior Vena Cava Left Innom.Vein Arch op Aorta Pulmonary Art. L Ventricle ^ipple- R. Ventricle Left Dome: Apex Point Fig. 48.— The relationship of the pericardium and heart to the sternum and ribs. this angle the pericardium may be drained ; by resecting part of the fifth and sixth cartilages its cavity may be explored. The right border of the pericardium is deeply placed and covered by the right lung (Fig. 47) ; in health it should not project more than 1 inch beyond the right sternal border. Besides the auricles and ventricles the follow- ing parts are contained in the pericardium : The 220 THE THORAX [Chap. terminations of the inferior and superior venae cavae; the ascending aorta and pulmonary artery. The position of these parts, and of the arch of the aorta and its branches, is shown in Fig. 48. It will be observed that more than two-thirds of the anterior surface of the heart is made up of right ventricle and auricle ; consequently it is these parts which are usually perforated in stabs of the heart. The heart may be exposed for operative treat- ment by removal of the terminal inch or more of the fourth and fifth left costal cartilages. The heart may be freely handled and sutured ; the sur- geon's task is rendered difficult by its rapid motions and the respiratory movements of the pericardium and diaphragm. When the heart is wounded, blood escapes into the pericardium, lead- ing to compression of the auricles and the arrest of the inflow of blood. Hydrops of the pericardium may cause death in a similar manner. Other things being equal, a wound of the ventricle is less rapidly fatal than is a wound of the auricle, owing to the thickness of the ventricular wall, and to its capacity for contracting and prevent- ing the escape of blood. Death in cases of wound of the heart would appear in a great number of cases to be due to an impression upon the nervous centres rather than to actual haemorrhage. Many instances have been recorded to show that the heart may be very tolerant of foreign bodies in its substance. Thus a man lived for twenty days with a skewer traversing the heart from side to side (Ferrus). In another case a lunatic pushed an iron rod, oyer 6 inches in length, into his chest, until it disappeared from view, although it could be felt beneath the skin receiving pulsation from the heart. He died a year following, and the metal was found to have pierced not only the lungs but also the ventricular cavities (Tillaux). Wounds of the heart have been sutured, the in- sertion of the stitches causing only momentary disturbance of its action. Travers has sutured X] THE MED1ASTINA 221 a wound of the right ventricle into which he was able to place three fingers to prevent haemor- rhage. Apropos of chest wounds, Velpeau cites the case of a man in whose thorax was found a part of a foil that entirely transfixed the chest from ribs to spine, ahd that had been introduced fifteen years before death. In the museum of the Royal College of Surgeons is the shaft of a cart that had been forced through the ribs on the left side, had passed entirely through the chest, and had come out through the ribs on the right side. The patient had lived ten years. Paracentesis of the pericardium. — As already mentioned, the pericardium may be tapped or drained through the left costo - ensif orm angle (Fig. 48). The extent to which it is covered by the left pleura and lung is extremely variable, but in the majority of cases it may be tapped in the left fourth and fifth spaces, up to 1 inch from the sternum, without injuring the pleura. The internal mammary artery descends in these spaces J an inch from the sternum, and divides, behind the seventh cartilage, into its superior epigastric and musculo-phrenic branches. The media stina.— Abscess in the anterior mediastinum may have developed in situ, or may have spread down from the neck. In like manner posterior mediastinal abscesses may arise from diseases of the adjacent spine, or lymphatic glands, or may be due to the spreading down- wards of a retropharyngeal or retro-oesophageal collection of matter. The employment of Rontgen rays in the diag- nosis of intrathoracic disease has greatly enlarged our knowledge of the respiratory movements and relationships of the thoracic viscera. In Fig. 49 (from a careful drawing given by Dr. Halls Dally) a representation is given of the more important parts seen when the chest is examined in an axis passing from the right nipple to the left scapula of the patient. The heart and liver appear as shadows, moving downwards and 222 THE THORAX [Chap. forwards in inspiration, upwards and backwards in expiration. As the diaphragm descends, and the heart moves away from the spine, the pos- terior mediastinum, containing the aorta and oesophagus, appears as a transradiant triangle. With inspiration, too, the lungs clear up and become more transparent. The anterior medias- tinum also is seen as a clear space. In the superior mediastinum may be seen the arch of Ant. Mediastinum Diaph. in Expirat. DlAPH. IN INSPIRAT. Translucent Triangle Fig. 49.— Orthodiagram of the thorax. (After Br. Halls Bally.) The position of parts is shown in extreme inspiration ; the position of the diaphragm and liver in expiration is also shown. the aorta as it passes backwards from the manu- brium to the fourth dorsal vertebra. In the in- dividual from whom Dr. Halls Dally constructed the diagram given in Fig. 49, the vertical move- ment of the diaphragm amounted to 3 inches. In normal respiration the vertical movement varies from \ to f of an inch. The azygos veins, commencing as they do below in the lumbar veins, and having more or less direct communications with the common iliac, renal, and other tributaries to the vena cava, are able to a great extent to carry on the venous circula- XJ THOEACIC DUCT 223 tion in cases of obstruction of the terminal part of the superior vena cava. In this they are as- sisted by the vense comites of the internal mam- mary artery and epigastric veins; the intraverte- bral veins also become greatly enlarged, and serve as anastomotic channels between the superior and inferior caval systems. These veins are apt to be pressed upon by tumours (such as enlarged gland masses) de- veloped in the posterior mediastinum, and to pro- duce in consequence some oedema of the chest walls by engorgement of those intercostal veins that they receive. Tumours growing in the pos- terior mediastinum may cause trouble by press- ing upon the trachea or gullet, or by disturbing the vagus nerve or the cord of the sympathetic. The numerous lymphatic glands which surround the trachea, bronchi, and oesophagus are often the seat of tuberculosis. They become adherent to these organs and may ulcerate into them. Thoracic duct. — Krabbel reports a case of fracture of the 9th dorsal vertebra associated with rupture of the thoracic duct. The patient died in a few days, and the right pleura was found to contain more than a gallon of pure chyle. The bodies of the upper lumbar and lower dorsal vertebrae are frequently the site of tuber- culosis ; so are the apical parts of the lungs. Dr. WoodyJones has drawn attention to the close relationship of these parts to the thoracic duct, and to the possibility of a tubercular invasion beginning from the alimentary canal being con- veyed to these sites of election by the duct. The receptaculum chyli is formed on the bodies of the first and second lumbar vertebrae, from which the duct ascends in the posterior mediastinum in front of the lower dorsal vertebrae. In cases of cancer of the stomach, the cervical glands round the termination of the thoracic duct may become enlarged bv secondary growths at an early stage of the disease. The secondary dissemination takes place by means of the thoracic duct. PART III.-THE UPPER EXTREMITY CHAPTER XI THE REGION OF THE SHOULDER A study of the region of the shoulder comprises the clavicle, the scapula, the upper end of the humerus, and the soft parts that surround them, together with the shoulder-joint and axilla. Surface anatomy.— The clavicle, acromion process, and scapular spine are all subcutaneous, and can be readily felt. In the upright position, when the arm hangs by the side, the clavicle is, as a rule, not quite horizontal. In well-developed subjects it inclines a little upwards at its outer end.* In the recumbent posture, the weight of the limb being taken off, the outer end rises still higher above the sternal extremity. The degree of the elevation can be best estimated by a study of frozen sections. Thus, in making horizontal sections of the body, layer by layer, from above downwards, Braune found that by the time the sterno-clavicular articulation was reached, the head of the humerus would be cut across in the lateral part of the section (Fig. 50). The deltoid tubercle of the clavicle may, if large, be felt through the skin, and be mistaken * Tn some women, in the feeble, and in some narrow-shouldered men the clavicle may be horizontal, or its outer end may incline downwards. 224 Chap. XIJ EEGION OF THE SHOULDER 225 for an exostosis. The acromioclavicular joint lies in the plane of a vertical line passing up the middle of the front of the arm. A prominence is sometimes felt about this joint in place of the level surface that it should present. This is due to an enlargement of the end of the clavicle, or to a thickening of the fibro-cartilage sometimes found in the joint. In many cases it has ap- peared to me to be due to a trifling luxation up- wards of the clavicle depending upon some stretch- ing of the ligaments. It is certain that the dry bone seldom shows an enlargement such as to account for this very common prominence at the acromial articulation. The sternal end of the clavicle is also, in muscular subjects, often large and unduly prominent, and sufficiently conspicu- ous to suggest a lesion of the bone or joint when none exists. The roundness and prominence of the point of the shoulder depend upon the development of the deltoid and the position of the upper end of the humerus. The deltoid hangs like a curtain from the shoulder girdle, and is bulged out, as it were, by the bone that it covers. If the head of the humerus, therefore, be diminished in bulk, as in some impacted fractures about the anatomical neck, orbe removed from the glenoid cavity, as in dislocations, the deltoid becomes more or less flat- tened, and the acromion proportionately promi- nent. The part of the humerus felt beneath the deltoid is not the head, but the tuberosities, the greater^ tuberosity externally, the lesser in front. A considerable portion of the head of the- bone can be felt by the fingers placed high up in the axilla, the arm being forcibly abducted so as to bring the head in contact with the lower part of the capsule. The head of the humerus faces very much in the direction of the internal condyle. As this relation, of course, holds good in every posi- tion of the bone, it is of value in examining injuries about the shoulder, and in reducing dislocations by manipulation, the condyle being i 226 THE UPPER EXTREMITY [Chap. used as an index to the position of the upper end of the bone. In thin subjects the outline and borders of the scapula can be more or less distinctly made out, but in fat and muscular subjects all parts of the bone, except the spine and acromion, are difficult of access in the ordinary positions of the limb. To bring out the superior angle and verte- bral border of the bone, the hand of the subject should be carried as far as possible over the oppo- site shoulder. To bring out the inferior angle and axillary border, the forearm should be placed behind the back. The angle formed at the point of junction of the spine of the scapula and the acromion is the best point from which to take measurement of the arm, the tape being carried down to the external condyle of the humerus. The upper border of the scapula lies on the second rib, its lower angle on the seventh. When the arm hangs from the side with the palm of the hand directed forwards, the acromion, external condyle, and styloid process of the radius all lie in the same line. The groove between the pectoralis major and deltoid muscles can usually be made out. In it run the cephalic t vein and a large branch of the acromio-thoracic artery. Near the groove, and a little below the clavicle, the coracoid process may be felt. This process, however, does not actually present in the interval between the two muscles, but is covered by the innermost fibres pi the deltoid. The position of the coraco-acromial ligament may be defined, and a knife thrust through the middle of it should strike the biceps tendon and open the shoulder- joint. When the arm hangs at the side with the palm forwards, the bicipital groove^ may be defined directly below the acromioclavicular joint. Just below the clavicle is a depression, the sub- clavicular fossa, which varies considerably in depth in different subjects. It is obliterated in subcoracoid dislocations of the humerus, in frac- XI] KEGION OF THE SHOULDER 227 tures of the clavicle with displacement, by many axillary growths, and by some inflammations of the upper part of the thoracic wall. In sub- clavicular or infracoracoid dislocation the fossa is replaced by an eminence. In this region, at a spot to the inner side of the coracoid process, and corresponding nearly to the middle of the clavicle, the pulsations of the axillary artery can be felt against the second rib. Just below the clavicle the interspace between the sternal and clavicular portions of the pectoralis major can often be made out. The anterior and posterior borders of the axilla are very distinct. The anterior border, formed by the lower edge of the pectoralis major, follows the line of the fifth rib. The depression of the armpit varies, other things being equal, with the position of the upper limb. It is most deep when the arm is raised from the side at an angle of about 45°, and when the muscles forming the bor- ders of the space are in a state of contraction. As the arm is raised above the horizontal line the depression becomes shallower, the head of the bone projecting into the space and more or less obliter- ating it, while the width of the fossa is encroached upon by the approximation of the anterior and posterior folds. The coraco-brachialis muscle itself forms a distinct projection along the humeral side of the axilla when the arm is raised to a right angle with the body. If the arm be brought nearly close to the side, the surgeon's hand can be thrust well up into the axilla, and the thoracic wall explored as high up as the third rib. The axillary glands cannot be felt when they are in a normal condition. The central set lies beneath the axillary tuft of hair. The direction of the axillary artery, when the arm is raised from the side, is represented by a line drawn from the middle of the clavicle to the humerus at the inner side of the coraco-brachialis. A line drawn from the third rib near its cartilage to the tip of the coracoid process indicates the 228 THE UPrER EXTREMITY [Chap. upper border of the pectoralis minor, and the spot where this line crosses the line of the axillary artery points out the position of the acromio- thoracic artery. A line drawn from the fifth rib Fig. 50.— Horizontal section of the body just below the upper border of the manubrium. (Braune.) a, Manubrium ; b, head of humerus ; c, clavicle ; d, first rib ; e, second rib ; /, third dorsal vertebra ; g, spine of second dorsal ; h, pec- toralis major ; i, deltoid ; j, infraspinatus ; k, subscapularis ; 1, coraco-brachialis and biceps ; m, pectoralis minor ; n, serratus magnus ; o, intercostals ; p, semispinalis and multifidus spinsB ; <7, biventer cervicis and complexus ; r, longissimus dorsi ; s, sple- nius colli ; t, rhomboideus ; w, trapezius ; v, sterno-thyroid ; w, sterno-hyoid ; T, thymus ; L, lung ; 1, left innominate vein ; 2, left carotid artery ; 3, left subclavian artery ; 4, vertebral artery ; 5, left subclavian vein ; 6, cephalic vein ; 7, phrenic nerve ; 8, vagus ; 9, transverse scapular artery. near its cartilage to the tip of the coracoid process indicates the lower border of the pectoralis minor, and the position of the long thoracic artery which runs along that border. The line of the sub- scapular artery corresponds to the lower^ border of the subscapularis muscle along which it runs, XI] THE CLAVICLE 229 but the position of this border can only be ap- proximately indicated on the living or undissected subject. The circumflex nerve and posterior circumflex artery cross the humerus in a horizontal line that is about a finger's breadth above the centre of the vertical axis of the deltoid muscle. This point is of importance in cases of supposed contusion of the nerve. These various indications of the positions of the main branches of the axillary artery are made while the arm hangs in its natural position at the side. The dorsalis sca- pulae artery crosses the axillary border at a point corresponding to the centre of the vertical axis of the deltoid. The clavicle. — The skin over the clavicle is loosely attached, and is easily displaced about the bone. This circumstance may serve to explain why the skin so often escapes actual wound in contusions of the clavicular region, and in part explains the infrequency of penetration of the integument in fractures of the clavicle. The three supraclavicular nerves that cross the clavicle are branches of the third and fourth cervical nerves, and it is well to note that pain over the collar bone is sometimes a marked feature in disease of the upper cervical spine. This symp- tom is then due to irritation of these nerves at their points of exit from the spinal canal. A communica- tion between the external jugular and cephalic veins is occasionally^ seen to cross the clavicle. Beneath the clavicle the great vessels and the great nerve-cords lie upon the first rib. The vein is the most internal, and occupies the acute angle between the collar-bone and the first rib. It will be seen that growths from the bone may readily press upon these important structures, and that the vein, from its position, as well as from the slighter resistance that it offers, is likely to be the first to be compressed. These structures have also been wounded by fragments of bone in fracture of the clavicle. Fortunately, between 230 THE UPPER EXTREMITY [Chap. the clavicle and these large nerves and vessels the subclavius muscle is interposed. This muscle is closely attached to the under surface of the bone, is enveloped in a dense fascia, and forms one of the chief protections to the ves- sels in case of fracture. This interposing pad of muscle is also of great service in resection operations. Braune states that by pressing the clavicle against the first rib in the dead body a stream of injection in the thoracic duct can, in some cases, be entirely arrested. Behind the clavicle the following structures may be noted, viz. the innominate, subclavian, and external jugular veins, the subclavian, suprascapular, and internal mammary arteries, the cords of the brachial plexus, the phrenic nerve and nerve of Bell, the thoracic duct, the omo-hyoid, scalene, sterno-hyoid and sterno-thyroid muscles, and the apex of the lung. The sternal end of the bone is not far removed from the innominate or left carotid artery, the vagus and recurrent nerves, the trachea, and the oesophagus. These relations of the clavicle are given to show the dangers in the way of partial _ or complete resections of the bone. The difficulties and risks of the operation increase as one progresses from the acromial to the sternal end. Resection of the acromial third of the bone is comparatively easy, but resection of the sternal portion is difficult and dangerous. The entire clavicle has been re- moved with success, and the operation has been followed by less impairment of the arm movements than would be imagined. The clavicle forms the sole direct bony con- nexion between the upper limb and the trunk, and in severe accidents, this connexion being broken through, it is possible for the extremity to be torn off entire. Thus Billroth reports the case of a boy aged 14, whose right arm, with the scapula and clavicle, was so torn from the trunk by a machine accident that it was only attached by a strip of skin 2 inches wide. Other XI] FRACTURES OF THE CLAVICLE 231 similar cases of avulsion of the limb have been reported. Fractures of clavicle, — The clavicle is more fre- quently broken than is any other single bone in the body. This frequency is explained by the fact that the bone is very superficial, is in a part exposed to injury, is slender and contains much compact tissue, is ossified at a very early period of life, and above all receives a large part of all shocks communicated to the upper extremity. The common fracture, that due to^ indirect violence, is oblique, and very constant in its position, viz. at the outer end of the middle third of the bone. So closely is the outer third of the clavicle bound by ligaments to the coracoid and acromion pro- cesses that it may be regarded as part of the scapula. Hence the impact resulting from a fall on the shoulder is transferred to the clavicle at the junction of its outer and middle thirds. The bone breaks at the point where the force is trans- ferred to the clavicle from the scapula. - The posi- tion of the coraco-clavicular ligaments is no doubt of the greatest import in localizing the^ fracture in this position, since a clavicle experimentally subjected to longitudinal compression does not break at this spot (Bennett). The displacement that occurs is as follows. The inner fragment remains unchanged in position, or its outer end is drawn a little upwards by the sterno-mastoid. It will be seen that any action of this muscle would be resisted by the pectoralis major and the rhomboid ligament. The outer frag- ment undergoes a threefold displacement. (1) It is carried directly downwards. This is effected mainly by the weight of the limb aided by the pectoralis minor, the lower fibres of # the pectoralis major, and the latissimus dorsi. (2) It is carried directly inwards by the muscles that pass from the trunk to the jshpulder, viz. the levator anguli scapulae, the latissimus dorsi, and especially by the pectorals. (3) The fragment is rotated in such a way that the outer end projects forwards, 232 THE UPPER EXTREMITY [Chap. the inner end backwards. This rotation is brought about mainly by the two pectorals, as- sisted prominently by the serratus magnus. The normal action of this latter muscle is to carry the scapula forwards, and the clavicle, acting as a kind of outrigger to keep the upper limb at a proper distance from the trunk, moves forwards at the same time and keeps the scapula direct. When this outrigger is broken the serratus can no longer carry the scapula directly forwards. The bone tends to turn towards the trunk, and the point of the shoulder is therefore seen to move inwards as well as forwards. The fragments in this fracture must consequently overlap, and as the displacement is difficult to remedy, it follows that in no bone save the femur is shortening so uniformly left as after an oblique fracture of the clavicle. The degree of shortening very seldom exceeds one inch. The deformity associated with this fracture is well corrected when the patient assumes the recumbent position. In this posture, the weight of the limb being taken off, the down- ward displacement is at once remedied. The "point of the shoulder falling back also tends to relieve in part the inward displacement, and the rotation of the outer fragment forwards. It is through the scapula, however, that these two latter displacements are in the main removed. In the recumbent posture the scapula is pressed closely against the thorax, with the result that its outer extremity (and with it, of course, the outer frag- ment of the clavicle) is dragged outwards and backwards. Some surgeons, recognizing this im- portant action of the scapula in remedying the displacement in these cases, strap the scapula firmly against the trunk, while at the same time they elevate the arm. Fractures due to direct violence are usually transverse, and may be at any part of the bone. When about the middle third they present the dis- placement just described. W T hen the^ fracture is between the conoid and trapezoid ligaments no XI] FRACTURES OF THE CLAVICLE 233 displacement is possible. When beyond these liga- ments, the outer end of the outer fragment is car- ried forwards by the pectorals and serratus, and its inner end is a little drawn up by the trapezius. In this fracture there is no general displacement downwards of the outer fragment, since it can- not move in that direction unless the scapula go with it, and the scapula remains fixed by the coraco-clavicular ligaments to the inner fragment of the clavicle. The clavicle may be broken by muscular vio- lence alone. Polaillon, from a careful analysis of the reported cases, concludes that the muscles that break the bone are the deltoid and clavicular part of the great pectoral. In no case does the fracture appear to have been produced by the sterno-mastoid muscle. The commonest movements producing fracture appear to be violent move- ments of the limb forwards and inwards, or up- wards. These fractures are usually about the middle of the bone, and show no displacement other than that of both fragments forwards, i.e. in the direction of the fibres of the two muscles first named. The clavicle is more frequently the seat of green-stick fracture than is any other bone in the body. Indeed, one-half of the cases of broken collar-bone occur before the age of five years. This is explained by the fact that the bone is ossified at a very early period, and is in a break- able condition at a time when most of the other long bones still present much unossified cartilage in their parts. Moreover, the periosteum of the clavicle is unduly thick, and not very closely attached to the bone, circumstances that greatly favour subperiosteal fracture. A reference to the relations of the bone will show that important structures may be wounded in severe fractures associated with much displace- ment and with sharp fragments. Several cases are reported of paralysis of the upper limb (as a rule incomplete) following upon fracture of this I* 234 THE UPPER EXTREMITY [Chap bone. In some # cases this symptom was due to actual compression or tearing of some of the great nerve cords by the displaced fragments. In other cases the nerve injury, while due to the original accident, was yet independent of the broken clavi^ cle. Paralysis of the biceps, brachialis anticus, and supinator longus, muscles supplied through the upper cord, may result from heavy weights being carried on the shoulder. Cases are reported of wound of the subclavian artery, of the sub- clavian vein, of the internal jugular vein, and of the acromio-thoracic artery. In several instances the fracture has been associated with wound of the lung, with or without a fracture of the upper ribs. The clavicle begins to ossify before any bone in the body. At birth the entire shaft is bony, the two ends being still cartilaginous. There is one epiphysis for its sternal end which appears be- tween the eighteenth and twentieth year, and joins the shaft about twenty-nve.^ It is a mere shell, is closely surrounded by the ligaments of the sternal joint, and cannot, therefore, be well separated by accident.* In cases where the clavicle is described as congenitally absent, the membrane-formed part of the bone is represented by^ a ligamentous cord; the cartilage-formed extremities are repre- sented by bony ' nodules. Defective ossification of the clavicle is commonly associated with an imperfect ossification of the^ membrane-formed bones of the skull, the condition being known as cranio-cleido-dysostosis, a disease of which Mr. D. Fitzwilliams has recently collected sixty examples. The defect in the clavicle may be so limited as to resemble a fracture. Sterno-clavicular joint. — Although this is the only articulation that directly connects the upper limb with the trunk, yet it is possessed of * Mr. Heath {Lancet, Nov. 18, 1S82) reports a case which is probably unique. It concerns a lad, aged 14, who, when in the act of bowling at cricket, tore the clavicle away from its epiphyseal cartilage, which remained in situ. The muscle producing the accident was apparently the pectoralis major. XIJ STEKNO-CLAVICULAK JOINT 235 such considerable strength that luxation at the joint is comparatively rare. The amount of move- ment in the joint depends to a great extent upon the lack of adaptability between the facets on the sternum and the sternal end of the clavicle. The disproportion between these parts is maintained by the interarticular cartilage, which reproduces only the outline of the clavicular surface. The cavity of the joint is V-shaped, since the clavicle only touches the socket atits inferior angle when the arm hangs by the side. When the arm is elevated, however, the two bones are brought in more immediate contact, and the joint cavity be- comes a mere slit. Thus, in disease of this articu- lation it will be found that of all movements of the joint the movement of the limb upwards is the most constant in producing pain. The joint is supplied by the suprasternal nerve. The movements permitted at this joint are limited, owing to ' the anterior and posterior sterno-clavicular ligaments being moderately tense in all positions of the clavicle. Movement forwards of the clavicle on the sternum is checked by the posterior ligament, and resisted by the an- terior ligament. This latter ligament ismore lax and less substantial than is the posterior band. Its weakness serves in part to explain the fre- quency of the dislocation forwards. Movement of the clavicle backwards on the sternum is checked by the anterior ligament, while the passage of the head of the bone is resisted by the powerful posterior band. The movement is also opposed by the rhomboid ligament. To produce, therefore, a dislocation backwards con- siderable force must be used. Disease of the sternoclavicular joint. — This articulation ^ is really divided into two joints by the interarticular cartilage, each being provided with a distinct synovial membrane. These joints are liable to the ordinary maladies of joints, and it would appear that the disease may commence in, and be for some time limited •236 THE UPPEE EXTREMITY [Chap. to, only one of the synovial sacs. In time the whole articulation usually becomes involved, but even in advanced cases the mischief is sometimes restricted to the synovial cavity on one side of the cartilage. According to some authors, this joint is more frequently involved in pyaemia than is any other. When effusion has taken place into the sterno-clavicular joint, and especially after sup- puration has ensued, the swelling usually makes itself evident in front, owing to the fact that the anterior sterno-clavicular ligament is the thinnest and least resisting of the ligamentous structures about the articulation. For the same^ reason the pus usually escapes from the anterior surface when it discharges itself spontaneously. Dislocations of the sterno-clavicular joint. — The clavicle may be dislocated from the sternum in one of three directions, which, given in order of frequency, are : (1) forwards, (2) backwards, (3) upwards. The relative frequency of these dis- locations can be understood from what has been already said as to the action of the ligaments in restricting movements. The displacement for- wards involves entire rupture of the capsule, and more or less damage to the rhomboid ligament. The head of the bone, carrying with it the sterno- mastoid, rests on the front of the manubrium. The dislocation backwards may be due to direct or indirect violence, and has occurred spontane- ously in connexion with the chest deformity in Pott's disease. The capsule is entirely torn, as is also the rhomboid ligament. ^ The head is found in the connective tissue behind the sterno-hyoid and sterno-thyroid muscles. In this position it may cause severe dyspnoea, or dysphagia, by pressure upon the trachea or gullet. < In the luxation upwards, due usually to indirect vio- lence, the head rests on the upper border of the sternum between the sterno-mastoid and sterno- hyoid muscles. It involves more or less complete tearing of all the ligaments of the joint, together with avulsion of the interarticular fibro-cartilage. XI] ACH0MI0-CLAV1CULAE JOINT 237 The non-adaptability of the joint surfaces in this part serves to explain the ease with which these luxations are usually reduced, and the diffi- culty of retaining the clavicle in position after it is replaced. A <• io in i o-c I :i \ i <• n I a r joint. — This articulation is shallow, and the outlines of the two bones that enter into its formation are such that no obstacle is offered to the displacement of the clavicle from the acromion. The joint, indeed, depends for its strength almost entirely upon its ligaments. The plane of the joint would be represented by a line drawn from above downwards and inwards be- tween the two bones. This inclination of the joint surfaces serves to explain the fact that the usual luxation of this part takes the form of a displace- ment of the clavicle upwards on to the acromion. The capsule that surrounds the joint is lax and feeble, and it is partly from its comparative thin- ness that effusion into this joint, when it is the seat of disease, makes itself so soon visible. The joint, however, depends mainly for its strength upon the powerful conoid and trapezoid liga- ments. The effects of shock at this joint are les- sened by the presence of a partial fibro-cartilage which projects between the bones from the upper part of the capsule. As the movements permitted in this joint may be impaired by accident or disease, it is well to note the part the articulation takes in the move- ments of the extremity. The scapula (and with it, of course, the arm), as it glides forwards and backwards upon the thorax, moves in the arc of a circle whose centre is at the sterno-clavicular joint, and whose radius is the clavicle. As the bone moves forwards it is important, for reasons to be immediately given, that the glenoid cavity should also be directed obliquely forwards. This latter desirable condition is brought about by means of the acromio-clavicular joint. Without this joint the whole scapula as it passed forwards with the outer end of the clavicle would precisely 238 THE UPPEK EXTKEMITY/ [Chap. follow the line of the circle above mentioned, and the glenoid cavity would look in an increasingly inward direction. It is essential that the surface of the glenoid cavity should be maintained as far as possible at right angles to the long axis of the humerus. When these relations are satisfied, the humerus has the support behind of a stout sur- face of bone, and it is partly to obtain the value of this support that the boxer strikes out from the side, i.e. with his humerus well backed up by the scapula. If there were no acromio-clavicular joint the glenoid fossa would offer little support to the humerus when the limb was stretched for- wards, and a blow given with the limb in that position, or a fall upon the hand under like con- ditions, would tend to throw the humerus against the capsule of the shoulder-joint, and so produce dislocation. Normally, therefore, as the scapula and arm advance, the angle between the acromion and the adjacent portion of the clavicle becomes more and more acute, and the glenoid fossa is maintained with a sufficiently forward direction to give substantial supportto the humerus.* It will thus be seen that rigidity of this little joint may be a cause of insecurity in the articulation of the shoulder, and of weakness in certain move- ments of the limb. There is also movement in this joint as the arm is lifted towards the head, the angle between the clavicle and axillary border becoming more acute as the shoulder is elevated. Dislocations of the acromioclavicular joint.— The clavicle may be displaced upwards on to the acromion or downwards beneath it. Polail- lon has collected thirty-eight cases of the former luxation, and six only of the latter. This dis- proportion is, in the main, explained by the direction of the articulating surfaces of the joint. Both luxations are usually due to direct violence. The dislocation upwards is very commonly only * For an excellent account of the mechanism of these joints, see Morris's " Anatomy of the Joints," p. 202 et seq. XI] THE SCAPULA 239 partial, and is associated only with stretching and some trifling rupture of ligaments. In the complete form, where the end of the clavicle rests entirely upon the acromion, there is rupture, not only of the capsule, but also to a greater or less extent of the coraco-clavicular ligaments. In the complete dislocation downwards, also, there is a rupture of the capsule, with extensive tearing of the conoid and trapezoid ligaments. These luxations are usually easily reduced, but it will be understood, from the direction of the articular surfaces, that in the displacement up- wards it is very difficult to retain the clavicle in situ when once reduced. Scapula. — At the posterior aspect of the bone the muscles immediately above and below the spine are somewhat precisely bound down by the deep fascia. Thus, the supraspinatus muscle is en- closed in a fascia that, being attached to the bone all round the origin of the muscle, forms a cavity open only towards the insertion of the muscle. The infraspinatus and teres minor muscles are also enclosed in a distinct, but much denser, fascia that is attached to the bone beyond these muscles, and blends in front with the deltoid sheath so as to form a second enclosed space. The arrange- ment of these fasciae serves to explain the trifling amount of ecchymosis that usually follows upon fractures of the scapular blade. The extravasa- tion of blood about the fracture is bound down by the fasciae over these muscles, and is unable, therefore, to reach the surface. Movements of the scapula. — In lifting the arm from the side to a vertical position over the head, the scapula undergoes a free rotatory movement, t its vertebral border passing from an approximately vertical to an approximately horizontal position. At the commencement of the movement, until the arm has ascended 35 degrees from the side, the angle of the scapula is practically stationary ; during this stage the scapula is fixed and maintained in position by 240 THE UPPER EXTREMITY [Chap. the trapezius, rhomboids, and serratus magnus. If the trapezius is paralysed, as may result from accidental section of the spinal accessory nerve in removing glands from the neck, the angle and vertebral border project backwards, under the weight of the raised arm. When the arm passes beyond 35 degrees, the serratus magnus comes into action, and the angle of the scapula moves rapidly forwards. If the nerve to this muscle be paralysed (the nerve of Bell from 5, 6, 7 c.) or if its antagonists — the rhomboids — which are also then in action, be paralysed (nerve from 5 a), then the angle and posterior border of the scapula become prominent or " winged " — evidence of the paralysis of these muscles. Thus "winging" of the scapula at the commencement of the movement indicates paralysis of the trape- zius ; if it occurs after the movement is well begun, then the serratus magnus is affected. Fractures of the scapula, and especially of the body of the bone, are not common, owing to the mobility of the part and the thick muscles that cover in and protect its thinner portions. It rests also upon a soft muscular pad, and derives, no doubt, additional security from the elasticity of the ribs. The most common lesion is a fracture of the acromion process. This is often but a separation of the epiphysis. There are two, sometimes three, epiphyseal centres for the acromion. Ossification appears in them about puberty, and the entire epiphysis joins with the rest of the bone from the twenty-second to the twenty-fifth year. Several cases of supposed fracture of the acromion united by fibrous tissue are probably but instances of an imperfectly-united epiphysis, and may have been independent of injury. In five bodies out of forty Symington found the acromial epiphysis united to the spine by a fibrous union, and from the statistics of other observers it appears that this is the case in quite 10 per cent, of adults. In fractures of the process much displacement is XI] FKACTURES OF THE SCAPULA 241 quite uncommon, owing to the dense fibrous cover- ing the bone derives from the two muscles attached to it. This dense periosteum also explains the circumstance that many fractures are incomplete and crepitus is often absent. When the fracture is in front of the clavicular joint, displacement of the arm is impossible. When it involves the joint, a dislocation of the collar bone is common. When behind the joint, the arm, having lost its sup- port from the thorax, is displaced in somewhat the same way as obtains in the common fracture of the clavicle. The coracoid process may present a genuine fracture, or may be separated as an epiphysis. As an epiphysis, it joins the main bone about the age of seventeen. The supra- glenoid tubercle, from which the long head of the biceps takes its origin, is part of the coracoid epiphysis. In spite of the powerful muscles at- tached to it, the displacement is usually slight, inasmuch as the coraco-clavicular ligaments are seldom torn. These ligaments, it may be noted, are attached to the base of the process. In some few cases the process has been torn off by mus- cular violence. Among the more usual fractures of the body of the scapula is a transverse or oblique fracture of its blade below the spine. Owing to the infra- spinatus, subscapulars, and other muscles being attached to both fragments, none but a trifling displacement is usual. A fracture may occur through the surgical neck. The surgical neck is represented by a narrowed part of the bone be- hind the glenoid fossa, and in the line of the suprascapular notch. The smaller fragment will, therefore, include the coracoid process, the larger, the acromion. The amount of deformity in these cases depends upon whether the coraco-clavicular and acromio-clavicular ligaments are entire or torn. If they be torn, the smaller fragment and the entire limb are displaced downwards, and the injury somewhat resembles a subglenoid disloca- tion. From this, however, it is distinguished by 242 THE UPPER EXTREMITY [Chap. the crepitus, by the ease with which the deformity is removed and the equal ease with which it re- turns, by the position of the head of the humerus in regard to the glenoid fossa, and by the con- spicuous fact that the coracoid process is displaced downwards with the limb._ Tumours of the scapula. — Tumours of various kinds grow from the scapula and mainly from the spongy parts of the bone — viz. the spine, the neck, and the inferior angle. The bone may be removed entire, with or without am- putation of the upper 'limb. An inter scajiulo- thoracic amputation is usually performed for malignant tumours which involve structures in the neighbourhood of the shoulder- joint. In this operation the upper extremity, including the scapula and the clavicle beyond the origin of the sterno-mastoid, is removed. An elliptical incision is made in front and behind the shoulder, the upper end of the ellipse lying on the clavicle, the lower at the angle of the scapula. The operation is commenced at the clavicle so as to secure the axillary vessels. The artery is tied before the vein so that the limb may continue to empty its blood into the circulation. The main vessels to be noted in connexion withthis operation are the suprascapular at the superior border of the bone, the posterior scapular about the vertebral border, the subscapular running along the lower border of the subscapularis muscle, the dorsalis scapulae crossing the axillary edge of the bone, and the acromial branches of the acromio-thoracic artery. Ttie axilla.— The axilla may be regarded sur- gically as a passage between the neck and the upper limb (Fig. 51). Axillary tumours and abscesses may spread up into the neck, and in like manner cer- vical growths and purulent collections may extend to the armpit. The skin forming the base of the axilla is provided with many short hairs and with numerous sebaceous and sudoriparous glands. In this integument small superficial abscesses are often met with, that arise usually from suppu- XI] THE AXILLA 243 ration of these glandular structures, and that are brought about by the friction of the skin against the clothing. Owing to the tendency of the axil- lary integument to become chafed and inflamed under friction, the axilla is not a good locality to select for the use of the mercurial inunction as applied in syphilis. Beneath the skin and super- ficial fasciae is the axillary fascia, and beyond this Gt. Tub. Bicip. Groove Fig. 51. — Relationship of the axillary artery and brachial plexus to the shoulder-joint and axilla. membrane is the axillary space. The connective tissue with which the axillary space is mainly occupied is very loose, and, while this laxity favours greatly the free movement of the arm, it at the same time permits of the formation of large purulent collections and immense extravasations of blood. It is important to remember the disposition of the fasciae about this region. There are three 244 THE UPPER EXTREMITY [Chap. layers principally concerned. (1) The deep pec- toral fascia that covers in and encloses the pector- alis major. (2) The clavi-pectoral fascia that, adherent above to the clavicle, fills in the space between that bone and the pectoralis minor, then splits to invest this muscle, and joins the deep pectoral layer at the anterior fold of the axilla to form with it the axillary fascia. The upper part of this fascia is generally known as the costo- coracoid me^mbrane. The whole membrane is some- times' known also as the " suspensory ligament of the axilla,' ■ since it draws up the axillary fascia towards the clavicle, and is mainly instrumental in producing the " hollow " of the armpit. (3) The axillary fascia that is formed by the union of the two preceding fasciae, and stretches across the base of the axilla from its anterior to its posterior fold. It is thinnest under the axillary hairs. Abscess about the axillary region maybe formed beneath the pectoralis major, or betweenthe two pectoral muscles, or beneath the pectoralis minor and clavi-pectoral fascia, and therefore in the axillary space. The loose tissue of the axillary space allows the formation of a large abscess cavity. The abscess as it fills the axilla pushes forwards the pectoralis major, more or less ob- literates the hollow of the armpit, thrusts back the scapula, and widens the angle between the serra- fcus magnus and the subscapularis muscles. There is a great tendency, therefore, for unrelieved ab- scesses to extend upwards into the neck, that being the direction in which the least amount of resist- ance is encountered. From the neck the purulent collection may extend into the mediastinum. In one case an axillary abscess, set up by shoulder- joint disease, perforated the first intercostal space and set up fatal pleurisy. In opening an axillary abscess, and, indeed, in most incisions into this space, the knife should be entered at the centre of the floor of the axilla, i.e. midway between the anterior and posterior margins, and near to the inner or thoracic side XIJ AXILLARY LYMPHATICS 245 of the space. The vessels most likely to be damaged by an indiscreet incision are the subscapular, running along the lower border of the subscapu- lars muscle; the long thoracic, following the lower border of the small pectoral; and the main vessels lying close to the humerus. The knife, if properly entered, should be midway between the two first-named vessels, and quite away from the main trunks. There is an artery (the external mammary) that sometimes comes off as the lowest branch of the axillary trunk, and crosses the middle of the axilla, to be distributed to the thorax below the long thoracic. This vessel would probably be wounded in the incision above named. The artery is, however, very inconstant, is small, and is not far below the surface. It is usually met with in female subjects. Lymphatic glands of the axilla. — The axillary glands are numerous, and of much surgical im- portance. They may be arranged in four sets (1) The greater number are placed to the inner side of the axillary vein beneath the axillary tuft of hair. This central set of glands receives the lymph from the upper extremity and breast. Pain in the axilla which follows whitlow or any septic infection of the arm is due to inflammation of this group, which is pierced by the intercosto- humeral nerve. (2) The deep axillary set lies along the axillary vessels. It receives the lymph from the central set and becomes continuous with the lower deep cervical glands in the subclavian triangle (Fig. 44, p. 197). (3) Other glands lie upon the serratus magnus muscle on the thoracic side of the axilla, and just behind the lower bor- der of the pectoral muscles. They receive ^ the lymphatics from the front of the chest, the princi- pal lymph vessels of the breast, and the superficial lymphatics of the abdomen as low down as the umbilicus. Their efferent vessels for the most part pass on to join the central set of glands. These glands will be the first to be enlarged in certain breast affections, and after blistering and other 246 THE UPPEE EXTEEMITY [Chap. superficial inflammations, etc., of the chest and upper abdomen. Paulet has seen them affected in inflammation of the hand. The axillary pro- cess of the female breast is in contact with this set. (4) The remaining glands are situated at the back of the axilla, along the subscapular vessels. They are joined by the lymphatics from the back. It may here be convenient to note that one or two glands are commonly found in the groove between the deltoid and pectoralis major muscles. They receive some vessels from the outer side of the arm and a part of the shoulder and breast. The superficial lymphatics over the upper part of the deltoid go to the cervical glands (Tillaux), over the lower half to the axilla. The lymphatics from the supraspinous fossa follow the supra- scapular artery, and join the lowest cervical glands. The superficial lymphatics of the back that converge to the axilla are derived from the neck over the trapezius muscle, and from the whole dorsal and lumbar regions as far down as the iliac crest. The complete removal of axillary glands is an operation frequently undertaken, especially in cases of mammary cancer. Free access to them is obtained by reflecting the pectoral muscles inwards. It will be understood from their posi- tion that these bodies, when diseased, are very apt to become adherent to the axillary vessels, and especially to the vein. The latter vessel has frequently been wounded or excised during the removal of gland tumours, and in one case at least the artery was accidentally cut (Holmes). Axillary vessels. — The axillary vein is formed by the union of the basilic with the two venae comites of the brachial artery. This union com- monly takes place at the lower border of the pectoralis minor muscle, and the vein is therefore shorter than the artery. Sometimes the vein does not exist as a single trunk until just below the clavicle. This condition, when it exists, is very unfavourable to operations upon the artery, as XIj AXILLARY VESSELS 247 many transverse branches cross that vessel to unite the veins that lie on either side of it. The axil- lary vein, being comparatively near the heart, is readily influenced as regards its contained blood by the inspiratory movement. Thus it happens that, in many instances of wound of the vessel or of its larger tributaries, air has been drawn into the venous canal and death has ensued. The en- trance of air into the main vein is perhaps aided by the circumstance that the costo-coracoid mem- brane (upper part of clavi-pectoral fascia) is ad- herent to the vessel, and thus tends to maintain it in a patent condition when wounded. This con- nexion with the fascia is supposed by some to account in part for the furious bleeding that occurs from this vein when it is divided. The vein is more often wounded than is the artery, it being larger, more superficial, and so placed as to more or less m overlap the arterial trunk. On the other hand, in injury to the vessel by traction, as, for example, in reducing disloca- tions, the artery suffers more frequently than the vein. In all positions of the upper limb the artery keeps to the outer angle of the axillary space. The relation of the vein, however, to the first part of the axillary artery, the part above the pectoralis minor, is modified by the position of the limb. Thus, when the arm hangs by the side the vein is to the inner side of the artery, and a little in front of it, but when the limb is at a right angle with the trunk the vein is drawn so far in front of the artery as to almost entirely conceal that vessel. Aneurysm is very frequent in the axillary artery, a fact to be explained by the nearness of the vessel to the heart, by the abrupt curve it pre- sents, by its susceptibility to frequent and exten- sive movements, and by its liability to share in the many lesions of the upper limb. In violent and extreme movements of the limb the artery may be more or less torn, especially if its walls are already diseased. 248 THE UPPER EXTEEMITY [Chap. In ligaturing the first part of the axillary artery it is well to note that the pectoralis major has sometimes a cellular interval between two planes of muscle fibre, and this may be mistaken for the space beneath it (Heath). If the pector- alis minor has an origin from the second rib, it may more or less entirely cover the artery and re- quire division. The cord of the brachial plexus nearest to the artery may be mistaken for that vessel, or easily included in a ligature intended for it (Fig. 51). A ready guide to the axillary vessels in this operation is to follow the cephalic vein. The anterior internal thoracic nerve appears between the vein and artery as it passes to the pectoralis minor ; it also may be useful occasionally as a guide. In applying a ligature to the third part of the artery, it should be borne in mind that a mus- cular slip sometimes crosses the vessels obliquely, passing from the latissimus dorsi to join the pec- toralis major, coraco-brachialis, or biceps mus- cles. This slip may give rise to confusion during the operation, and may be mistaken for the coraco-brachialis. Brachial plexus. — When the shoulder is depressed the upper and middle trunks of the brachial plexus, formed by the fifth, sixth and seventh cervical nerves, can be distinctly felt in the neck, passing from beneath the posterior border of the sterno-mastoid to enter the axilla just ex- ternally to the mid-point of the clavicle (Fig. 51). The upper trunk, formed by the fifth^ and sixth nerves, is by far the most exposed to injury, for the reason that it rises higher in the neck than the middle and lower trunks; hence when the neck is bent forcibly to the left, as when a burden is borne on the right shoulder, the upper trunk on the right side is subjected to a greater strain than the middle or lower cords. In cases of shoulder- presentation at birth, or if the neck and shoulder be forced apart by accident, the upper cord is lia- ble to be strained or ruptured, resulting in what is XI] AXILLARY NERVES 249 usually described as Erb's palsy. It will be re- called that the suprascapular, circumflex, and musculo-cutaneous nerves are derived from this trunk; so are the nerves to the rhomboids and serratus magnus. The rupture, however, ia usually distal to the origin of these nerves, and hence their muscles escape. The muscles affected in Erb's palsy are the supraspinatus, infraspina- tus, teres minor, deltoid, coraco-brachialis, biceps, brachialis anticus, and supinator longus; occa- sionally also the supinator brevis, extensor carpi radialis longior,, and pronator radii teres. No sensory paralysis is observed in such cases. Curi- ously enough, section of the fifth cervical gives as wide an area of muscular paralysis as section of the combined fifth and sixth (W. Harris). In complete rupture of the brachial plexus sensation is completely lost beyond the elbow, but in the arm and shoulder deep sensibility is retained (Sher- ren). The arm, in such lesions, retains intact the nerves received from the descending cervical and intercosto-humeral. Axillary nerves. — Any of the axillary nerves may be injured by a wound, the median being the most frequently damaged, and the musculo- spiral the least frequently. The comparative immunity of the latter is explained by its deep position, its situation at the inner and posterior aspect of the limb, and its large size. The nerves are very seldom torn by a traction on the limb short of more or less complete avulsion. Indeed, if forcibly stretched, they are disposed rather to become torn away from their attachments to the spinal cord than to give way in the axilla. Thus, Flaubert records a case where the last four cervi- cal nerves were torn away from the cord during a violent attempt to reduce a dislocated shoulder. The deltoid region. — This region, comprising as it does the " point " of the shoulder, is limited in all parts by the deltoid muscle. The deltoid covers the upper end of the humerus and the shoulder-joint (Fig. 52). Between the joint and 250 THE UPPEE EXTREMITY [Chap. the surface, therefore, are only the skin and super- ficial fascia, the deltoid in its sheath, and some loose connective tissue (the subdeltoid tissue) in which is found the great subacromial bursa. This subdeltoid tissue sometimes assumes the form of a distinct thick membrane, and may have an im- portant influence upon the localization of puru- lent collections proceeding from the joint. The PRASPINATUS SCAPU R0/1I0/1 Proc ELTOID CAPSULE: Bursa EPIPHYSEAL LlttE:'. Joimt Cavity Qleaioid Liqa/^e/it Capsule st.Circu/mflex Art. Teres /^Iajor Triceps Fig. 52. — Section of shoulder- joint to show the relations of the capsule, epiphyseal line, and bursa. {After Poirier.) fatty^ tissue over the deltoid is a favourite seat for lipomata, and it is in this situation that the tendency of these growths to change their position is sometimes seen. Thus, Erichsen records a case where the tumour slid downwards from the shoulder to the breast. Emerging from the interval between the two teres muscles, and winding horizontally round the shaft of the humerus, quite close to the bone, and XIJ THE SHOULDER-JOINT 251 about the line of the surgical neck, are the circum- flex nerve and posterior circumflex artery (Fig. 51). This nerve affords an example of an arrangement pointed out by Mr. Hilton, viz. that a principal nerve to a joint not only supplies the articular surfaces, butalso some of the main muscles that move that joint, and the skin over those muscles. This nerve supplies the shoulder-joint, the deltoid and teres minor muscles, and the skin over the lower two-thirds of the shoulder and upper part of the triceps. It is frequently damaged in injuries to the shoulder, and may be severely bruised by a simple contusion of the part, resulting in paralysis of the deltoid. It would appear, however, that damage to the circumflex is much less frequent after contusions of the shoulder than was formerly maintained. It will also be readily understood that the nerve is often torn in fractures of the surgical neck of the humerus, in dislocations of that bone (especially the luxa- tion backwards), and in violent attempts at reducing such dislocations (Fig. 51). The shoulder-joint.— From one surgical point of view, jointsmay be divided into (1) those that depend for their strength mainly upon ligaments ; (2) those that are mechanically strong, and that derive their stability to a great extent from the arrangement of their component bones; and (3) those that rely for their support principally upon muscles. As an example of the first kind may be cited the sterno-clavicular joint, of the second form the elbow-joint, and of the third the shoulder-joint. ^ The articulation the least prone to dislocation is the one that derives its strength from tough unyielding ligaments, while the one most often luxated belongs to the third variety, its strength being greatly dependent upon muscles that may be taken by surprise, and that may them- selves, from disordered action, prove sources of weakness. These are, of course, not the only fea- tures in the etiology of dislocation. A great deal depends upon the amount of movement permitted 252 THE UPPER EXTREMITY LChap. in a given joint, and the degree of leverage that can be brought to bear upon its parts. The arch formed by the coracoid and acromion processes and the ligament between them forms an essential support to the head of the humerus, and is an important constituent of the articulation. With this arch the humeral head is in immediate relation, though not in actual c6ntact (Fig. 52). In paralysis of the deltoid the head may be separated by some distance from the coracoid process, and Nannoni records the case of a child with old-standing paralysis of the deltoid, between whose humeral head and acromial vault four fin- gers could be lodged. It is well to note that at least two-thirds of the head of the bone are not in contact with the glenoid cavity when the arm hangs by the side, and Anger points out that in this position three-fourths of the circumference of the humeral head are in front of a vertical line drawn from the anterior border of the acromion process. In this posture, also, the head is wholly to the outer side of the coracoid process. The margin of the glenoid cavity is more prominent on the inner than on the outer side, while the strongest part of the margin and the broadest part of the fossa are below. This is significant, since it points to an attempt to strengthen a part of the joint that practice shows to be the weakest in the articulation, viz. the lower and inner por- tion of the capsule. It is at this place that the head of the bone leaves the joint in dislocation of the shoulder. The capsule of the shoulder-joint is very lax, and would lodge a bone-head twice as large as that of the humerus. According to Henry Morris, no one part of the capsule is constantly thicker than the rest, as is the case in the hip-joint. Of the bursas about the joint, the subacromial bursa is the one most frequently the seat of disease. This sac, when distended with fluid, may be mis- taken for the results of chronic inflammation of the joint (Fig. 52). XIJ THE SHOULDER-JOINT 253 Experiment shows that the walls of this bursa may be actually torn in twists of the arm, especi- ally when either flexed or extended (Nancrede). When the sac is distended most pain is elicited in the position of abduction, for in this posture the * bursal walls are normally folded up, so as to form a sort of collar in advance of the greater tuberosity. In elderly rheumatic people the sac sometimes communicates with the joint. The sub- scapular bursa may be regarded as an extension of the synovial membrane of the joint between the terminal part of the muscle and the scapula. Pain elicited when the arm is rotated at the shoulder-joint may be due to disease in the joint, in the subacromial or in the subscapular bursa, for a movement then occurs in all three. The biceps tendon strengthens the upper part of the joint, keeps the humerus against the glen- oid cavity in the various positions of the limb, and prevents the head of the bone from being pulled too closely upwards under the acromion. The tendon may be ruptured, and in such a case, in addition to the general weakening of the limb, and the peculiar projection formed by the con- traction of the muscle, the head of the humerus is usually drawn upwards and forwards until ar- rested by the coraco-acromial arch. Thus, a kind of slight false dislocation may be produced. In certain violent wrenches of the limb the tendon may rupture the transverse ligament which binds it down, slip from its groove, and be displaced to one or other side, usually to the inner side. The intracapsular part of the tendon may dis- appear in cases of chronic rheumatic arthritis, owing to the friction against the abraded arti- cular surface of the humerus. In such cases it acquires an attachment to the bicipital groove. Disease of the shouIder=joint.— This articulation is liable to all forms of joint disease. The capsule, as Just stated, is very lax, the articular surfaces being kept in apposition by the tonus of the sur- rounding muscles ; when chloroform is administered 254 THE UPPER EXTREMITY [Chap. the surfaces may be freely separated and examined. In joint disease, however, the effusion may effect a considerable separation of the two bones. Braune, having pierced the glenoid cavity through the supraspinous fossa, injected tallow at considerable pressure into the joint. When fully distended the humerus was found to be separated from the scapula by more than \ an inch, and this may serve to explain the lengthening of the limb often noted in joint disease of this part with much effusion. When the greatest degree of distension of the capsule was reached the humerus became slightly extended and rotated inwards. It is significant that in shoulder-joint disease it is com- mon for the arm to be found close to the side, the elbow carried a little back (extension), and the limb rotated inwards. This position may also be due to the rigid contraction of the muscles about the joint. When such contractions exist it may be inferred that the powerful latissimus dorsi has a little advantage over its^ opponents, and may be answerable for the rotation in and slight projection backwards of the arm. The inner part of the epiphyseal cartilage is just within the capsule ; the outer, anterior and posterior parts are entirely subperiosteal^ It happens, therefore; that the pus in suppurative epiphysitis will find its way into the joint. There are two diverticula from the synovial membrane : (1) one that runs some way down the bicipital groove with the tendon ; (2) a cul-de : sac beneath the subscapular^ formed by a communica- tion between the synovial cavity and the bursa under that muscle. When the joint is filled with effusion, the capsule is evenly distended and the shoulder evenly rounded. Special projections usually occur at the seats of the diverticula. Thus a swelling often appears early in the course of a synovitis in the groove between the # pectoralis major and the deltoid muscles, and this swelling may appear bilobed, being cut in two by the unyielding biceps tendon (Paulet). Fluctuation XI] DISLOCATIONS OF THE SHOULDER 255 can best be felt by examining the uncovered part of the capsule in the axilla beyond the sub- scapular muscle. When the joint suppurates, pus usually escapes at one of the culs-de-sac just mentioned, most often through the one that fol- lows the biceps tendon. Pus may thus extend for some way along the bicipital groove. In one recorded case, pus that had escaped from the shoulder-joint followed the course of the musculo- spiral nerve, and opened on the outer side of the elbow. Dislocations. — Dislocations at this joint are more common than at any other joint in the body. This is explained by the shallowness of the glenoid fossa, the large size and globular shape of the head of the humerus, the extensive movements of the arm, the long leverage it affords, and the depend- ence of the articulation for its strength mainly upon muscles. The upper limb and shoulder are also peculiarly exposed to injury. The principal forms of luxation of the humerus at the shoulder are : 1. Subcoracoid, forwards and a little downwards; the usual form. 2. Sub- glenoid, downwards and a little forwards; rare. 3. Subspinous, backwards ; rare. In all complete dislocations the head of the bone leaves the joint cavity through a rent in the capsule. In so-called "false luxations" the capsule is not torn. For example, in the cadaver, if the deltoid be divided the humeral head can be displaced under the coracoid process without rupture of the capsule, and the same thing may occur during life, in cases where the muscle has long been paralysed. In all cases of dislocation at this joint the primary displacement is always downwards into the axilla. It is well known that dislocations at the shoulder are usually due to violence applied to the limb while the arm is abducted, or to severe direct violence forcing the bone downwards. Now, when the limb is abductedthe head of the humerus projects below the glenoid fossa, and rests and 256 THE UPPER EXTREMITY [Chap. presses upon the inferior and least protected part of the capsule. The fibres of this portion of the capsule being tightly stretched in this position, it requires no extraordinary force to tear the ligament and drive the bone into the axilla. Thus it happens that in luxations at this joint the rent in the capsule is at its inferior and inner aspect, the humeral head lying beneath the sub- scapulars, which is always strained and some- times torn. The head of the bone, being thus driven downwards into the axilla, may, for cer- tain reasons, remain there (subglenoid form), or more usually it will be drawn forwards and in- wards by the powerful pectoralis major, aided by other muscles whose action is now less resisted and by the weight of the unsupported limb (sub- coracoid form) ; and lastly, the direction of the violence being applied markedly from in front, the head of the bone may be thrust backwards under the acromion or spinous processes (sub- spinous form). The overwhelming frequency of the subcoracoid variety is explained by the greater advantage at which those muscles act that draw the bone forwards, in comparison with those that would draw it backwards, and by the very trifling opposition offered to the passage of the head for- wards when compared with the substantial ob- stacles in the way of its passage backwards under the scapular spine. Features common to all dislocations at the shoulder. — As the roundness of the deltoid depends to a great extent upon the presence beneath it of the humeral head, and as in all these luxations (save perhaps in the slighter grades of the subspinous form) the head is removed practi- cally from its connexion with the deltoid, that muscle^ is always more or less flattened. This flattening is augmented by the stretching of the muscle, which in some degree is constantly pre- sent. Stretching of the deltoid inyolves abduc- tion of the arm, and this symptom is fairly con- stant in all the luxations. The biceps being also XI] DISLOCATIONS OF THE SHOULDER 257 more or less unduly tense, the elbow is found flexed and the forearm supinated. In every form there is some increase in the vertical circumfer- ence of the axilla, since the head, having left the glenoid fossa, must occupy some part comprised within that circumference. Again, Dr. Dugas has pointed out that " if the lingers of the in- jured limb can be placed by the patient, or by the surgeon, upon the sound shoulder while the elbow touches the thorax (a condition that obtains in the normal condition of the joint), there can be no dislocation ; and if this cannot be done there must be one, for no injury other than a disloca- tion can induce this physical impossibility." This depends upon the fact that in consequence of the rotundity of the thorax it is impossible for both ends of the humerus to touch it at the same time, and in luxation at the shoulder the upper end of the bone is practically touching the trunk. Lastly, from the position of the great vessels and nerves (Fig. 51) it will be seen that in the subcoracoid and subglenoid luxations the head of the bone may press injuriously upon those structures. Thus may result oedema of the limb and severe pain or loss of muscular power. The artery is usually saved by its greater elasticity ; but Berard reports a case of displacement forwards where the axillary artery was so compressed by the humeral head as to induce gangrene of the limb. The close connexion of the circumflex nerve with the humerus renders it # very liable to injury, especially in the subglenoid and subspinous forms of dislocation. Special anatomy of each form of shoulder dis- location. 1. Subcoracoid. — The # articular head of the humerus lies on the anterior surface of the neck of the scapula, and the anatomical neck rests on the anterior lip of the glenoid fossa. The head is thus placed immediately below the coracoid process, and is in front of, internal to, and a little below, its normal site. The great tuberosity faces the empty glenoid cavity 258 THE UPPER EXTREMITY [Chap. (Fig. 53). The subscapulars muscle is stretched over the head of the humerus, and is usually partly torn. The supraspinatus, infraspinatus, and teres minor are stretched or torn, or the great tuberosity may even be wrenched off. The coraco-brachialis and short head of the biceps are tense, and are immediately in front of the head of the humerus instead of to its inner side. The long tendon of the biceps is de- flected downwards and outwards. It is sometimes, although rarely, torn from its groove. The del- t o i d is put upon the stretch. The prominence formed by the humeral head in the front of the axilla depends to some degree upon the amount of rotation. If the bone be rotated out, the projection is most distinct ; but if rotated^ in, its head sinks into the axilla and is brought more in contact with the scapula than with the skin. The head of the bone being always carried a little downwards, some lengthening must in all cases really exist; but with the ordinary method of measuring the limb this lengthening may be replaced by a normal measurement, or even by apparent shortening, if the head of the bone be carried a good deal forwards and inwards, and the limb be abducted. When the head has left the glenoid cavity, abduction tends to bring the Fig. 53. — Subcoracoid dislocation of the humerus. XI] DISLOCATIONS OF THE SHOULDER 259 external condyle nearer to the acromion, and these are the two points between which the measurement is usually taken. Thus the apparent length of the arm depends mainly upon the degree of abduc- tion of the humerus, or the obliquity of the axis of the bone. 2. Subglenoid. — The head is below, and a little in front of and internal to, its normal position. It cannot go directly downwards, owing to the situation of the long head of the triceps, but escapes in the interval between that muscle and the subscapularis. The articular surface of the head rests on the anterior aspect of the triangular area just below the glenoid fossa that gives origin to the triceps. The upper border of the great tuberosity is in close relation with the lower margin of the joint. The subscapularis muscle, which binds down the humeral head, is much stretched or torn. The supraspinatus and the infraspinatus are stretched or torn, and the two teres muscles have not been much affected unless there be considerable abduction of the arm. The coraco-brachialis and biceps are stretched, and owing to the amount of abduction usually present, the biceps tendon is but little deflected from a straight line. 3. Subspinous. — The head usually rests on the posterior surface of the neck of the scapula, the groove of the anatomical neck of the humerus corresponding to the posterior lip of the glenoid fossa. _ The head is thus placed beneath the acromion ; but it may be displaced still farther back, and may rest on the dorsum scapulae, and beneath the scapular spine (Fig. 54). The sub- scapularis tendon is drawn right across the glenoid fossa, and is often torn from its attach- ment. The head pushes back the hinder part of the deltoid, the infraspinatus and teres minor muscles. These latter cover the bone, and are stretched over it. The great pectoral is rendered unduly tense, and this serves in part to explain the rotation inwards of the humerus, and the 260 THE UPPER EXTREMITY [Chap. abduction forwards, that are usually observed, those movements being more or less unopposed. The circumflex nerve is often torn. In reducing dislocations, especially such as are of long standing, serious damage may be inflicted on the axillary structures. The axillary artery suffers most frequently, the vein rarely, and the nerves still less often. The artery, being placed externally, is apt to contract adhesions to the soft parts covering the head of the displaced bone, and therefore to be torn when those parts are disturbed (Fig. 51). Fractures of the upper end of the hu- merus, l. Anatomical neck. — The upper part of the capsule is ex- actly attached to the anatomical neck, and in this situation the fracture may run beyond the ligament and be partly extra- capsular (Fig. 52, p. 250). The lower part of the capsule is inserted some little way below the ana- tomical neck, and in this position, therefore, the lesion must be intracapsular. From the line of attachment of the lower part of the capsule to the humerus, fibres are reflected upwards to the margin of the articular cartilage on the head of the bone. These fibres, if unruptured, may serve to connect the fragments. It is easy for the small and comparatively dense upper fragment to be driven into the wide surface of cancellous bone exposed on the upper surface of the lower fragment. When impaction occurs, there may bo Fig. 54. — Subspinous disloca- tion of the humerus. XI] FRACTURES OF THE HUMERUS 261 some flattening of the deltoid, since the head is rendered of less dimensions by that impaction, and consequently causes a less projection of the deltoid. The difficulty of obtaining crepitus in non-impacted fractures will be obvious when the small size of the upper fragment is considered, together with its great mobility, and the obstacles in the way of so fixing it that one broken end may be rubbed against the other. The diagnosis of such obscure cases is now cleared up by the aid of Rontgen rays. 2. Separation of the upper epiphysis. — The lower border of this epiphysis is represented by a line crossing the bone at the base of the great tuberosity and placed between the anatomical and surgical necks (see Fig. 52, p. 250). It would be fairly indicated by a transverse saw-cut through the widest part of the bone. The three component nuclei of this epiphysis (head, greater and lesser tuberosities) fuse together about the fifth year, and the entire mass joins the shaft about the twentieth year. The upper fragment may be carried and rotated a little outwards by the muscles attached to the great tuberosity, while the lower fragment is drawn inwards and for- wards by the muscles inserted into the bicipital groove. Thus, a part of the smooth upper end of the lower fragment commonly forms a distinct projection below the coracoid process. In such case the axis of the limb would be altered, and the elbow carried a little from the side. Often, however, the displacement is solely in the antero- posterior direction, the lower fragment project- ing forwards. So wide are the two bone surfaces at the seat of injury that it is scarcely possible for them to overlap one another. 3. Surgical neck. — The surgical neck is situated between the bases of the tuberosities and the in- sertions of the latissimus dorsi and teres major muscles. A common displacement of parts is the following. The upper fragment is carried out and rotated out by the supra- and infraspinatus 262 THE UPPEE EXTEEMITY [Chap. and teres minor. The upper end of the lower fragment is drawn upwards by the deltoid, biceps } coraco-brachialis, and triceps, inwards by the muscles attached to the bicipital groove, and for- wards by the great pectoral. Thus it forms a projection in the axilla, and the axis of the limb is altered so that the elbow projects from the side. This displacement, however, is by no means con- stant. Pean, Anger, and others maintain that the usual deformity is a projection of the upper end of the lower fragment forwards, and that this deviation is due to the nature and direction of the violence, and not to muscular action. In some cases there is no displacement, the broken ends being retained in situ, probably, by the biceps tendon and the long head of the triceps. In at least one instance (Jarjavay) the lower fragment was so drawn upwards and outwards, apparently by the deltoid, as to nearly pierce the skin of the shoulder. Hamilton comes to the general con- clusion " that complete or sensible displacement is less common at this fracture than in most other fractures/ ' and in this conclusion many surgeons agree. Amputation at the shoulder-joint. — The deltoid muscle forms an ideal amputation flap. It has its blood and nerve supply secured for it by the posterior circumflex vessels and circumflex nerve, which require to be avoided as the flap is raised from the posterior aspect of the upper extremity of the humerus prior to division of the capsule. The coracoid process lies under the anterior border of the muscle, and immediately externa^ to the line of the axillary vessels. Thence the preliminary incision, which commences just externally to the coracoid, and is carried down the arm along the anterior border of the muscle, gives access to the axillary vessels so that they may be secured below the origin of the posterior circumflex and above the origin of # the superior profunda. The in- cision is carried backwards above the insertion of the deltoid to the humerus. The insertion of XI J AMPUTATION AT SHOULDEE- JOINT 263 the pectoralis major is cut in the incision along the anterior border of the deltoid; so are the latissimus dorsi and teres major. The insertions of the teres minor, infraspinatus, supraspinatus and subscapularis are adherent to the capsule and are cut through with it, so as to free the head of the bone. The lower part of the capsule and the long head of the triceps are severed after the head of the humerus has been raised from its socket through the upper wound. CHAPTER XII THE ARM The arm, upper arm, or brachial region is con- sidered to extend from the axilla above to the region of the elbow below. Surface anatomy. — In women, and in those who are fat, the outline of the arm is rounded and fairly regular. It is less regular in the mus- cular, in whom it may be represented by a cylinder, somewhat flattened on either side and unduly prominent in front (biceps muscle). The outline of the biceps muscle is distinct, and on either side of it is a groove. The inner of the two grooves is by far the more conspicuous. It runs from the bend of the elbow to the axilla, and indicates generally the position of the basilic vein and brachial artery. The outer groove is shal- low, and ends above at the insertion of the deltoid muscle. So far as it goes it marks the position of the cephalic vein. The insertion of the deltoid is an important landmark, and can be easily distinguished. It indicates very precisely the middle of the shaft of the humerus, is on the same level with the in- sertion of the coraco-brachialis muscle, and marks the upper limit of the brachialis anticus. It corresponds also to the spot where the cylindrical part of the humeral shaft joins the prismatic portion, to the point of entrance of the nutrient artery, and to the level at which the musculo- 264 Chap. XII] SURFACE ANATOMY OF ARM 265 spiral nerve and superior profunda artery cross the back of the bone. When the arm is extended and supiinated, the brachial artery corresponds to a line drawn along the inner border of the biceps, from the outlet of the axilla (at the junction of its middle and an- terior thirds) to the middle of the bend of the elbow. The artery is superficial, and can be felt in its entire extent. In its upper two-thirds it lies on the inner aspect of the shaft of the humerus, and can be compressed against the bone by pressure in a direction outwards and slightly backwards. In its lower third the humerus lies behind it, and compression, to be effectual, should be directed backwards. The inferior profunda would be represented by a line drawn from the inner side of the humeral shaft at its middle to the back part of the internal condyle. The nutrient artery enters the bone at its inner aspect opposite the deltoid insertion, and the anastomotic vessel comes off about 2 inches above the bend of the elbow. The ulnar nerve follows first the # brachial artery, and then a line drawn from the inner side of that vessel, about the level of the insertion of the coraco-brachialis, to the gap between the inner condyle and the olecranon. The main part of the internal cutaneous nerve is beneath the inner bicipital groove, while the musculo-cutaneous nerve becomes superficial in the bend of the elbow at the outer margin of the tendon of the biceps. The skin of the arm is thin and smooth, especially in front and at the sides. It is very mobile, being but loosely attached to the deeper parts by a lax subcutaneous fascia. In circular amputations of the arm this looseness of the integument allows it to be sufficient^ drawn up by traction with the hand only. It is from the integument covering the anterior surface of the biceps that the flap is fashioned in Taglia- cozzi's operation for the restoration of the nose. The fineness of the skin of this part, and its J* 266 THE UPPER EXTREMITY [Chap. freedom from hairs, render it very suitable for this procedure. The scanty attachments of the skin of the arm allow it to be readily torn or stripped away in lacerated and contused wounds. Some- times in these lesions large flaps of integument are violently dissected up. The looseness of the subcutaneous tissues favours greatly the spread of inflammatory processes, while its comparative thinness allows of the early manifestation of ecchymoses. The limb is completely invested with a deep fascia, the brachial aponeurosis, as by a sleeve. The fascia is held down at the sides by the two intermuscular septa which are attached along the outer and inner margins of the humerus, running from the deltoid insertion to the outer condyle on the one side, and from the coraco-brachialis inser- tion to the inner condyle on the other. By means of this aponeurosis and its septa the arm is divided into two compartments, that can be well seen in transverse sections of the limb (Fig. 55, p. 270). These compartments serve to confine in- flammatory and hemorrhagic effusions. The an- terior of the two spaces has the less substantial boundaries, owing to the thinness of the brachial fascia as it covers the biceps. Effusions can readily pass from one compartment to the other by following the course of those structures that, by piercing the intermuscular septa, are common to both spaces. These are the musculo-spiral and ulnar nerves, the superior and inferior profunda, and anastomotic arteries. The principal struc- tures that pierce the brachial aponeurosis itself are the basilic vein, a little below the middle of the arm, the internal cutaneous nerve, about the middle, and the external cutaneous nerve, at the elbow. The two first-named are in the inner bicipital groove, and the last-named in the outer. The brachialis anticus is closely adherent to the bone, while the biceps is free. It follows, therefore, that in section of these muscles, as in amputation, the latter muscle retracts more con- XII] BRACHIAL ARTERY 267 siderably than does tho former. It is well, there- fore, in performing a circular amputation, to divide the biceps muscle first, and then, after it has retracted, to cut the brachialis anticus. Brachial artery. — The line of this vessel has already been given. It is well to note that in the very muscular the artery may be over- lapped to a considerable extent by the biceps muscle. Compression of the brachial, unless per- formed carefully with the fingers, can hardly avoid at the same time compression of the median nerve. It must also be remembered that the in- ternal cutaneous nerve lies in front of the vessel, or close to its inner side, until it pierces the fascia; that the ulnar nerve lies along the inner side of the artery as far as the coraco-brachialis insertion ; and that behind the commencement of the vessel is the musculo-spiral nerve. The vense comites are placed one on either side of the artery, and communicate frequently with one another by short transverse branches which directly crossthe vessel, and which may give trouble in operations upon the artery. If in ligaturing the artery at its middle third the arm rests upon any support, the triceps may be pushed up and mistaken for the biceps. If the incisions be too much to the inner side the basilic vein may be cut, or the ulnar nerve exposed and mistaken for the median. Tillaux states that in the operation a large in- ferior profunda artery has been taken for the brachial. Inasmuch as the median nerve often derives distinct pulsation from the subjacent ves- sel, it happens that in the living subject it has been confused with the main artery itself. Abnormalities in the arrangement of the bra- chial artery are so frequent (they occur in 12 to 15 per cent, of arms) as to be of surgical im- portance. It is not unusual to find a collateral branch (vas aberrans) arising from the upper part of the brachial or lower part of the axillary, passing down the arm, superficially to the median nerve, and ending in the radial or sometimes the 268 THE UPPER EXTREMITY LChcip. ulnar artery. The vas aberrans may replace the brachial, in which case the artery will be found superficial instead of deep to the median nerve, and the profunda vessels arise from the remnant of the real brachial artery. This superficial brachial vessel may pass under the supra- condyloid process, a hooked projection of bone which occasionally springs from the humerus, 2 inches above the epicondyle. It is situated amongst the inner fibres of origin of the brachialis anticus. The musculo-spiral nerve, from its close contact with the bone, which it crosses at the level of the deltoid insertion, is frequently injured and torn. Thus it has been damaged in severe con- tusions, in kicks, in stabs, in bites from horses, and very frequently in fractures of the humeral shaft; or the nerve may be sound at the time of fracture, and become subsequently so involved in callus as to lead to paralysis of the parts it supplies. In a case reported by Tillaux, where paralysis followed some time after a frac- ture, the nerve was found embedded in callus, and on cutting some of the redundant mass away a good recovery followed. In several instances the nerve has been paralysed by the pressure of the head when a man has slept with his head resting on the arm in the position of full supination and abduction. It is said to be often paralysed in Russian coachmen who fall asleep with the reins wound round the upper arm. It has also been frequently damaged by the pressure of badly con- structed crutches, especially those that afford no proper support for the hand. Indeed, it is the nerve most often affected in " crutch paralysis,' ' the ulnar being the trunk that suffers next in frequency. Fracture of the shaft of the humerus is usually due to direct ^ violence. The shaft may, however, be broken by indirect violence, and of all bones the humerus is said to be the one most frequently fractured by muscular action. As ex- XII] FRACTURE OF THE HUMERUS 269 amples of the latter may be noted the throwing of a ball, the clutching at a support to prevent a fall, and the so-called trial of strength known as " wrist-turning.' ' When the bone is broken above the deltoid insertion the lower fragment may be drawn upwards by the biceps, triceps, and del- toid, and outwards by the last-named muscle; while the upper fragment is drawn inwards by the muscles attached to the bicipital groove. When the fracture is below the deltoid insertion, the lower end of the upper fragment may be carried outwards by that muscle, while the lower frag- ment is drawn upwards to its inner side by the biceps and triceps. The deformity, however, as a rule depends much more upon the nature and direction of the force that breaks the bone than upon any muscular action. The displacements just noted may be met with, but usually they are quite independent of the relation of the deltoid insertion to the seat of fracture, and cannot be tabulated. The weight of the arm seldom allows of more than f of an inch of shortening. The humerus is more frequently the seat of non-union after fracture than is any other bone. This result is quite independent of the position of the fracture in relation to the nutrient artery. Hamilton's explanation is briefly this : The frac- ture is usually so adjusted that the elbow is flexed; this joint soon becomes fixed by muscular rigidity, and when any movement is made as if to flex or extend the forearm on the arm, that movement no longer occurs at the elbow- joint, but at the seat of fracture. Thus, if the arm be in a sling, and the patient allows the hand to drop by relaxing that sling, it is maintained that the bulk of that movement will take place about the fracture line. There are many objections to this theory. If true, the tendency to movement about the fragments would be the greater the farther the fracture is from the elbow- joint, but non- union is more common at the middle than at the upper third of the shaft. Probably many causes 270 THE UPFER EXTREMITY [Chap. conspire to bring about non-union of fractures of this bone, among which may be mentioned the imperfect fixing of the joint above the fracture, and the inadequate support afforded to the elbow, whereby the weight of the arm and of the splints tends to drag the lower fragment out of the proper line it should form with the upper frag- ment. The most effective cause would appear to be the entangle- ment of muscular tissue between the broken ends, for it must be re- membered that the shaft of the bone is closely surrounded by muscular fibres that are directly adherent to its surfaces. Thus, in an oblique fracture the end of one fragment may be driven into the brachia- lis anticus, while the other end projects into the substance of the triceps, and im- mediate contact of the bones may be consequently prevented. Amputation through the middle of the arm.— The parts divided in a circular amputation are fully shown in Fig. 55. In the flap method there is a danger of transfixing the brachial artery. The artery, as may be seen from Fig. 55, may be pushed forwards or backwards by^ pres- sure applied to the muscles between which it lies. Before the flaps are shaped, the vessels may be secured at the inner border of the biceps. Fig. 55. — Transverse section through the middle of the arm. {Braune.) a, Biceps ; b, coraco-brachialis ; c, brachialis anticus ; d, triceps ; 1, brachial artery ; 2, median nerve ; 3, ulnar nerve ; 4, musculo-spiral nerve. XII] AMPUTATION OF THE AEM 271 In the anterior flap are included the biceps, the greater part of the brachialis anticus, with the musculo-cutaneous nerve between them, and a small piece of the triceps from the inner side of the limb. In the posterior flap are the triceps, any small part of the outer portion of the brachialis not included in the anterior flap, the superior profunda artery, and the musculo-spiral nerve. CHAPTER XIII THE REGION OF THE ELBOW Surface anatomy. — On the anterior aspect of the elbow are seen three muscular elevations. One, above and in the centre, corresponds to the biceps and its tendon ; while, of the two below and at the sides, the outer corresponds to the supina- tor longus and the common extensor mass, and the inner to the pronator radii teres and the common set of flexor muscles. The arrangement of these elevations is such that two grooves are formed, one on either side of the biceps and its tendon. The grooves diverge above, and join the outer and inner bicipital grooves, while below they meet over the most prominent part of the tendon, and thus form together a V-shaped depression (Fig. 56). The distinctness of these details depends upon the thinness and muscular development of the individual. In the inner of the two grooves are to be found the median nerve, the brachial artery and its veins; while deeply placed below the outer groove are the terminations of the mus- culo-spiral nerve and superior profunda artery, with the small radial recurrent vessel. The biceps tendon can generally be felt distinctly. Its outer border is more evident than is its inner edge, owing to the connexion of the bicipital fascia with the latter side of the tendon. Extending transversely across the front of this region is a crease in the integument, the " fold of the elbow. " This fold is not a straight line, but is 272 - Chap. XIII] REGION OF THE ELBOW 273 convex below. It is placed some little way above the line of the articulation, and its lateral ter- minations correspond to the tips of the two con- dylar eminences. In backward dislocations of the elbow the lo v wer end of the humerus appears about 1 inch below this fold, whereas in a fracture of the humerus just above the condyles the fold is either opposite to the prominence formed by the lower end of the upper fragment, or is below it. This crease is obliterated on extension. At the apex of the V-shaped depression, about the spot where the biceps tendon ceases to be dis- tinctly felt, and at the outer side of that tendon, the median vein divides into the median basilic and the median cephalic. At the same spot also the deep median vein joins the superficial vessels. The median basilic vein can be seen to cross the biceps tendon, to follow more or less closely the groove along the inner border of the muscle, and to join, a little above the internal condyle, with the posterior ulnar vein to form the basilic trunk. The median cephalic, following the groove at the outer margin of the biceps, joins, about the level of the external condyle, with the radial vein to form the cephalic vein. The brachial artery bifurcates 1 inch below the centre of a line drawn from^ one condyle to the other; the point of division is opposite the neck of the radius. " The coronoid process of the ulna can be indistinctly felt, if firm pressure is made in the triangular space in front of the joint " (Chiene). The points of the two condyles can always be felt. The in- ternal condyle is the more prominent and the less rounded of the two. The humero-radial articula- tion is in a horizontal Jine, but the humero-ulnar joint is oblique, the joint surfaces sloping down- wards and inwards. Thus it happens that while the external condyle is only f of an inch (18 mm.) above the articular line, the point of the internal condyle is more than 1 inch (28 mm.) above that part (Paulet). From the obliquity of the joint surfaces between the ulna and humerus, it follows 274 THE UPPER EXTREMITY [Chap. that the forearm, when in extension, is not in a straight line with the upper arm, but forms with it an angle that opens outwards. Thus, when traction is made upon the entire upper limb from the wrist, some of the extending force is neces- sarily lost, and such traction, therefore, should be applied from the elbow, as is the usual practice in reducing a dislocation of the shoulder by manipulation. A line drawn through the two condyles will be at right angles with the axis of the upper arm ?> while it ^ will form externally a smaller angle with the axis of the forearm. Thus, if we look at the upper arm, the two condyles are on the same level, whereas, when viewed from the forearm, the inner condyle lies at a higher level than does the external process. The joint line of the elbow is equivalent only to about two-thirds of the width of the entire line between the points of the two condyles (Fig. 58, p. 287). The prominence of the condyles forms a capital point d'appui for traction by encircling bands applied to the limb above the elbow-joint. At the back of the elbow the prominence of the olecranon is always to be distinctly felt. It lies nearer the internal than the external condyle. In extreme extension the summit of the olecranon is a little above the line joining the two condyles. When the forearm is at right angles with the arm, the tip of the process is below the line of the condyles, and in^ extreme flexion it lies wholly in front of that line. Between the olecranon and the inner condyle is a depression that lodges the ulnar nerve and the posterior ulnar recurrent artery. To the outer side of the olecranon, and just below the^ external condyle, there is a depression in the skin which is^ very obvious when the limb is extended. This pit is to be seen even in those who are fat, and also in young children. In it the head of the radius and radio -humeral joint can be felt, and can be well distinguished when the bone 5s rotated in pronation and supination. XIII 1 SKIN OF THE ELBOW 275 The pit corresponds to the hollow between the outer border of the anconeus and the muscular eminence formed by the two radial extensors of the carpus and the supinator longus. The highest point of the bone that can be felt moving on rotation will correspond to the radius immediately below the line of the elbow- joint, and is a valuable guide to that articulation. The upper limit of the elbow-joint reaches a line drawn between the point of the two condyles. The tubercle of the radius can be felt just below the head of the bone when the limb is in the position of ex- treme pronation. The skin in front of the elbow m is thin and fine, and is ^ readily ex- coriated by tight bandag- ing and by improperly Fig. 56.-Left elbow from in front. applied splints. The thin- ness of the skin allows the ^ subjacent veins to be easily seen through the integuments, but the dis- tinctness with which these veins appear depends mainly upon the amount of subcutaneous fat. In the very stout they may be quite invisible, and it may be difficult or im- possible to render them evident by the usual means adopted in venesection. Tillaux points out that if such people are bled a pellet of fat a, Basilic vein ; b, cephalic vein ; c, on the ulna points to median basilic vein ; d, on the radius points to median cephalic vein ; e, radial vein ;/, median vein ; g, pos- terior ulnar vein. The bra- chial artery passes behind the median-basilic vein, and divides into its radial aud ulnar branches to the inner side of the radial neck. 276 THE UPPER EXTREMITY [Chap. will often project into the wound and prevent the flow of blood. The arrangement of the superficial veins in front of the elbow, so as to form an M-shaped figure, is familiar, but it must be confessed that it is by no means constant (Fig. 56). So far as I have seen, it would appear that the precise M-like arrangement figured in most books is only present in about two-thirds, and perhaps in only one- half, of all cases. The median vein breaks up into the median cephalic and median basilic, just to the outer side of the biceps tendon, and, therefore, the latter vein passes in front of the tendon, of the brachial artery and its veins, and of the median nerve. From these structures it is separated by the bicipital fascia. The median basilic vein may cross the brachial artery abruptly, and be com- paratively free of it, except at the point of cross- ing, or it may run for some distance quite in front of the artery, or, crossing it early, it may lie parallel with the vessel, although at a different level, for the greater part of its course. As re- gards size, the median basilic is usually the largest of these Veins, the median cephalic coming next, and the median itself third, while the ulnar and radial veins are the smallest of the series. These veins are liable to many abnormalities, some of the most conspicuous being in cases where the main arteries of the part also are abnormal. The deviation is more usual in the veins on the radial than in those on the ulnar side of the limb. Thus it is common for the radial or the median cephalic veins, or both, to be either very defec- tive or entirely absent. In spite of the relation the median basilic vein bears to the brachial artery, it is nevertheless the vein usually selected in venesection and transfusion. The reasons for its selection are these : it is usually the largest and most prominent of the veins, and the one the nearest to the surface; it is also the least movable vein, and the one the least subject to XIII] VEINS OF THE ELBOW 277 variation. The bicipital fascia forms an excel- lent protection to the brachial artery during phlebotomy. The density of that membrane varies, and depends mainly upon the degree of muscular development. In thin subjects the median basilic vein may receive pulsations from the subjacent artery. According to one observer, the walls of this vein are often as thick as those of the popliteal vein. The ulnar, radial, and median veins seldom yield enough blood on vene- section, since they are below the point of junction of the deep median vein, and thus do not receive blood from the deep veins of the limb. The brachial artery has, as may be supposed, been frequently injured in bleeding; and at the period when venesection was very commonly practised, arterio-venous aneurysms at the bend of the elbow were not infrequent. Since the principal super- ficial lymphatic vessels run with these veins, and since some of them can scarcely escape injury in phlebotomy, it follows that an acute lymphan- gitis is not uncommon after the operation, especi- ally when, the point of the lancet being unclean, septic matter is introduced into the wound. The internal cutaneous nerve, which usually runs in front of the median basilic vein, may be wounded in bleeding from that vessel. The in- jury to the nerve, according to Tillaux, may lead to " traumatic neuralgia of extreme intensity, and very chronic." A " bent arm " may follow after venesection, and Mr. Hilton believes this to be often due to injury to the filaments of the musculocutaneous nerve, especially to the inclu- sion of those filaments in a scar left by the opera- tion. The cutaneous branches of this nerve lie over the median cephalic vein. These peripheral fibres being irritated, the muscles supplied from the same segment of the cord (biceps and brachialis anticus) are caused to contract by re- flex action. Hence the bent arm. In one case he cured a bent arm following bleeding by resecting the old scar, which on removal was found to 278 THE UPPER EXTREMITY [Chap. have included within its substance some nerve filaments. There is a lymphatic gland situated over the internal intermuscular septum of the arm, and just above the internal condyle. It receives some of the surface lymphatics from the inner side of the forearm, and two or three inner fingers. In position, it is the lowest of the constant glands in the upper limb. In the same position occurs an occasional bony outgrowth of the inner aspect of the humerus — the supracondyloid process. The brachial artery, and also the median nerve, may pass beneath and internally to this process. Brachial artery.— In forcible flexion of the limb the artery is compressed between the mus- cular masses in front of the joint, and the radial pulse is much diminished or even checked. The artery may divide in the lower third of the arm, and in such cases the ulnar artery may pass over the bicipital fascia. Aneurysms at the bend of the elbow have been treated by flexion of the limb, that position bringing more or less direct pressure to bear upon the sac. In full extension of the joint the artery becomes flattened out, and the radial pulse diminished. In the over-ex- tension possible with fractured olecranon the pulse may be stopped at the wrist. Forcible ex- tension of an elbow that has become rigid in the bent position has caused rupture of the brachial artery. The ulnar nerve is, from its position at the elbow, very liable to be injured. It passes in a groove behind the internal condyle, and is crossed by a bridge of fibrous tissue which pre- vents its displacement. The nerve may pass in front of the internal condyle, and an instance is reported where the nerve slipped forward over that eminence whenever the elbow was bent (Quain). In exposing the ulnar nerve (for nerve- stretching, etc.) behind the elbow the nerve may be found quite covered by an occasional muscle, the epitrochleo-anconeus. XIII] THE ELBOW-JOINT 279 The elbow-join t.— The strength 9f this joint depends not so much upon either ligaments or muscles as upon the coaptation of the bony sur- faces. The relations of the olecranon and coronoid processes to the humerus are such that in certain positions the strength of the joint is very con- siderable. The elbow, being a pure hinge-joint, permits only of flexion and extension. These movements are oblique, so that in flexion the forearm in- clines inwards, carrying the hand towards the middle third of the clavicle. If it were not for the obliquity of the joint line it would be possible for the hand to be placed flat upon the shoulder of the same side, but this movement is only pos- sible after some excisions of the joint, for in this operation the oblique direction of the articular surfaces is not reproduced. In extreme extension the ulna is nearly in a straight line with the humerus as regards their lateral planes, while in extreme flexion the two bones form an angle of from 30° to 40°. Bursae. — Of the bur see about the joint the large subcutaneous bursa over the olecranon is very commonly found enlarged and inflamed (Fig. 57) ; and when inflamed may lead to exten- sive mischief in the limb. Its enlargement is favoured by certain employments involving pres- sure on the elbow ; thus, the disease known as 11 miner's elbow " is merely an enlargement of this sac. There is a bursa between the biceps tendon at its insertion and the bone, the relations of which to the nerves of the forearm are worth noting. A case, for instance, is reported where this bursa became chronically enlarged, and by pressing upon the median and posterior interosseous nerves produced loss of power in the forearm (Agnew). There is a small bursa at the insertion of the triceps (Fig. 57). Of the ligaments of the elbow- joint, the an- terior and posterior are comparatively thin, and the latter especially soon yields to the pressure of 280 THE UPPER EXTREMITY [Chap. fluid within the joint in disease of the articula- tion (Fig. 57). The internal lateral is the strong- est and most extensive of the ligaments of the part. From its rigidity, its extended attachment, and the fact that it serves to limit not only flexion and extension, but also any attempt to wrench the forearm laterally from the arm, it Triceps Olecramo/s /Iumerus Biceps Bracaiialis Armcus Capsule Sup. Loaicus. Epiphysis of Trochlea Coroaioid Bursa Biceps i/1ter055eus art. Fig. 57. — Vertical section of the elbow-joint. The epiphyseal lines of the olecranon and trochlea are shown in red. The joint is semi-extended. A, Usual cap-like epiphysis of olecranon receiving insertion of tri- ceps ; B, occasional epiphysis forming the upper third of the olecranon. Three bursae are shown— over the olecranon, under the insertion of the triceps, and at the insertion of the biceps. happens that it is the ligament that suffers the most often in M sprains " of the elbow. As this ligament is attached to the whole length of the inner border of the olecranon, it may assist in preventing separation of the fragments when that process has been fractured. Joint -disease. — In disease of this joint the effusion first shows itself by a swelling around XIII] DISEASE OF THE ELBOW-JOINT 281 the margins of the olecranon. This is explained by the facts that the synovial cavity is here nearest to the surface, and that the posterior ligament is lax and thin (Fig. 57). Some swelling is also soon noticed about the line of the radio-humeral joint, and fluctuation in this situation serves to distinguish joint effusion from simple enlargement of the bursa beneath the triceps tendon. Deep-seated swelling may be noted about the front of the joint beneath the brachialis anticus, owing to the thinness of the anterior ligament; and lastly, about the external condyle. The density of the internal ligament prevents bulging of the synovial membrane on the inner side. When the joint suppurates the pus will most easily reach the surface by travel- ling upwards and backwards between the humerus and the triceps, and the abscess points, therefore, very commonly at one or other border of that muscle. The pus may escape beneath the brachi- alis anticus in front, and discharge itself near the insertion of the muscle. The diseased elbow tends to assume the posture of semiflexion, and it is interesting to observe that that is the position assumed by the joint when forcible injections are made into its cavity (Braune). The joint, in fact, holds the greatest amount of fluid when it is semiflexed. As regards muscular rigidity of the elbow, due to reflex irritation from disease, it is well to note that all the nerves of the articu- lation, notably the musculo-spiral and musculo- cutaneous, supply muscles acting upon the joint. The relation of the ulnar nerve to the joint serves to explain cases where severe pain has been felt along the forearm and in the fingers, in parts corresponding to the distribution of that nerve. The upper epiphysis of the radius and the greater part of the lower epiphysis of the humerus are intrasynovial, i.e. come within the capsule of the joint (Fig. 58). The comparatively small upper epiphysis of the ulna is only partly within the capsule (Fig. 57). 282 THE UPPER EXTREMITY [Chap. Dislocations of the elbow. — These are many, and may be thus arranged. (1) Dislocations of both radius and ulna either backwards, outwards, inwards, or forwards (in order of frequency). (2) Dislocations of the radius alone either for- wards, backwards, or outwards (in order of fre- quency). (3) Luxation of the ulna alone back- wards. As a preliminary it may be convenient to note some general anatomical considerations in con- nexion with these various displacements. (a) Antero-posterior luxations are much more common than lateral luxations. — Displacements in the antero-posterior direction are more common because the movements of the joint take place in that direction, and the width of the articular surface of the humerus from before backwards is comparatively small. On the other hand, there is normally no lateral movement of the ejbow, and the width of the articulation from side to side is considerable. The antero-posterior ligaments are feeble, while the lateral ligaments are strong, and the joint, moreover, receives more muscular support at its sides than it does either behind or in front. The mutual support afforded by the bones to one another is weakened in the antero-posterior direction during certain move- ments. Thus in full flexion the olecranon has but a feeble hold upon the humerus, while in exten- sion the hold of the coronoid process upon that bone is even less. In a lateral direction, how- ever, movement has but a very slight effect upon the support the bones mutually derive from one another. (b) Both bones of the forearm- are m,ore often luxated together than js either the radius alone or the ulna alone. — This depends upon the power- ful ligamentous connexion between the radius and ulna on the one hand, and the absence of such connexion between the humerus and the radius on the other. In the dead subject it is not difficult to dislocate the two bones of the fore- XIII] DISLOCATIONS OF THE ELBOW 283 arm, but it is extremely difficult to separate the radius from the ulna without great breaking and tearing of parts. (c) The commonest dislocation of the two bones together is backwards, the rarest is forwards. — In the former instance the movement is resisted by the small coronoid process, in the latter by the large and curved olecranon. For like reasons the luxation outwards is less rare than is the dis- placement inwards, since the articular surface of the humerus inclines downwards and inwards on the inner side, and thus affords a greater obstacle in that quarter. (d) If a single bone be dislocated it will usually be the radius. — This follows from the absence of reliable union between that bone and the humerus, from the greater exposure of the radius (" the handle of the hand ,; ) to indirect violence, and from its greater mobility. The luxation is usually forwards, due to the fact that the forms of violence that tend most often to dis- place the bone tend also to draw it forwards. Paulet asserts that the posterior part of the ' orbicular ligament is "much more resistant " than is the anterior part. The luxation of the ulna alone occurs in the backward direction, for rea- sons that will be obvious. Dislocations of all kinds may be partial or complete. More usually they are complete when in the antero-posterior direction, and partial when the luxation is lateral. Some more detailed notice may now be taken of the only two forms of dislocation at the elbow that are at all common. 1. Displacement of both bones backwards. — This may be effected during forced extension. Here the point of the olecranon pressed against the humerus acts as the fulcrum of a lever of l:he second kind, with the result that the sigmoid cavity is forced away from the trochlea. The addition of violence to the forearm in a back- ward or upward direction would effect the actual 284 THE UPPER EXTREMITY [Chap. displacement. This condition may be illustrated by a fall, when running, upon the fully ex- tended hand. The lesion may also be produced by certain violent wrenchings of the limb.^ Mal- gaigne maintained that the particular kind of wrench most effectual in producing luxation was a twisting inwards of the forearm while the elbow was semiflexed. In this way the internal lateral ligament was ruptured, and the coronoid process twisted inwards and downwards under the humerus, and the bones thus displaced back. This lesion would be difficult to effect while the joint was fully flexed. In the complete form the coronoid process is opposite to the olecranon fossa. It can hardly occupy that hollow (as some- times described), since the connexion of the ulna to the radius, and the projection of the latter bone behind the outer condyle, would prevent it from actually falling into the fossa. The an- terior and the two lateral ligaments are usually more or less entirely torn, while the posterior and the orbicular ligaments escape. The biceps is drawn over the lower end of the humerus, and is rendered moderately tense. The brachialis anti- cus is much stretched and often torn. The an- coneus is made very tense. Both the median and ulnar nerves may be severely stretched. 2. Dislocation of the radius forwards. — This may be due to direct violence to the bone from behind, or to extreme pronation, or to falls upon the extended and pronated hand. The anterior, ex- ternal and orbicular ligaments are torn. There would seem to be a lack of evidence in support of Hamilton's statement that " sometimes the anterior and external lateral are alone broken, the orbicular ligament being then sufficiently stretched to allow of the complete dislocation." The biceps being relaxed, the pronators act, and the limb is either pronated or assumes a position midway between pronation and supination. Some stretching of the supinator brevis would probably modify the amount of pronation. A difficulty in XIII] SPRAIN OF THE ELBOW 285 the reduction is often due to the torn annular ligament coming between the head of the radius and the humeral condyle. Sprain of the elbow.— Mr. J. Hutchinson has shown that in young children, under 5 years, forcible traction of the limb in the supinated position may cause the radius to slip down- wards, away from the orbicular ligament, which is displaced upwards. In such cases traction is applied before the muscles of the elbow have had time to undergo their usual reflex con- traction, so that when the child is lifted by the hand all the weight falls upon the ligaments at the elbow instead of on the muscles. # The only ligaments which resist such a dislocation are (1) the oblique ulno-radial ligament, (2) the lower fibres of the orbicular ligament which grip the head. Flexion of the elbow in the pronated posi- tion restores the ligament to its normal position. It is clear that this displacement is the anatomical basis of the common sprain of the elbow met with in young children, and usually due to violent traction of the hand. Fractures of the lower end of the humerus — These are : (1) A fracture just above the con- dyles; (2) the " T-shaped fracture " involving the joint; (3) fractures of the internal, and (4) of the external condyle; (5) fracture of the internal epicondyle ; and (6) separation of the lower epi- physis. All these fractures are more common in the young. 1. The fracture "at the base of the condyles," as it is sometimes called, is usually situate a little above the olecranon fossa, where the humeral shaft begins to expand. It is commonly trans- verse from side to side, and oblique from behind downwards and forwards. It is generally the re- sult of a blow inflicted upon the extremity of the elbow. Probably the tip of the olecranon driven sharply against the bone acts like the point of a wedge, and takes an important share in the production of the fracture. The lower fragment, 286 THE UPPER EXTREMITY [Chap. together with the bones of the forearm, is gener- ally carried backwards by the triceps, and up- wards by that muscle, the biceps, and the brachi- als anticus. The median or ulnar nerves, especi- ally the latter, may be severely damaged. 2. The "T=shaped fracture" is but a variety of the lesion just noted. In addition to the trans- verse fracture above the condyles, there is also a vertical fracture running between the two con- dyles into the joint. The lower fragment is thus divided into two parts. The displacement is the same. The fracture is usually due to a fall upon the bent elbow, and here possibly the tip of the olecranon again acts as a wedge, producing the transverse fracture, while the prominent ridge along the middle of the greater sigmoid cavity, acting as a second wedge, produces the vertical fracture into the joint. 3, 4, and 5. For surgical purposes it is well to limit the term " condyle " to such parts of the extremity of the humerus as are within the cap- sule, and the term " epicondyle " to such parts of the lower projections of the bone as are with- out the joint. In the so-called fracture of the inner condyle the line of separation generally commences about half an inch above the tip of the epicondyle (and, therefore, outside the joint), and, running obliquely outwards through the olecranon and coronoid fossae, enters the articulation through the centre of the trochlear surface (Hamilton). The fragment is often displaced a little upwards, backwards, and inwards, the ulna going with it. In the fracture of the external condyle the line commences also above the epicondyle and outside the joint, and, running downwards, enters the joint usually between the trochlear surface and the surface for the radius. The displacement is trifling and inconstant. On account of its insignificant size, a fracture of the external epicondyle is scarcely possible. Fractures of the inner epicondyle are, however, XIII1 FEACTUKES OF THE HUMERUS 287 quite common, the joint remaining free (Fig. 58). This epicondyle exists as a distinct epiphysis, which unites at the age of eighteen, and which at any time before that age may be separated from the bone by direct injury or muscular violence. Owing to the dense aponeurotic fibres that cover the part, much displacement of the fragment is uncommon. When displacement exists, it is in the general line of the common flexor muscles that arise from the tip of the process. In such cases the ulnar nerve, which lies behind the process, is often damaged. 6. The lower epiphysis (Fig. 58).— In the car- tilaginous lower extrem- ity of the humerus, four ossific centres appear, one for each of the fol- lowing parts : capitel- lum, trochlea, external and internal epicon- dyles. The three centres named first unite to form the main epiphysis, that for the internal epicon- dyle remaining separate (Fig. t bS\ The epiphy- seal line is thus divided into two parts, and is irregular in form ; it lies both within and without the capsule of the joint (Fig. 58) ; Its position may be indicated by a line drawn from the upper border of the ex- ternal to the lower border of the internal epicon- dyle. The lower epiphy- sis joins the shaft at the age of seventeen. Thus, after seventeen the growth of the bone must depend upon the activity of the upper epiphysis, which does not unite until Fig. 58. — Lower epiphysis of the humerus from behind. A, Centre for internal epicon- dyle ; B, c, D, united centres or the trochlea, capitellum , and external epicondyle ; E, E, epiphyseal line ; the cap- sular attachment is indicated by red lines. ^88 THE UPPER EXTREMITY [Chap. twenty. Excision of the elbow, therefore, after the sixteenth or seventeenth year, will not be fol- lowed by arrest of development in the limb, even if the epiphyseal line has been transgressed by the saw. Several cases are, however, reported of marked arrest of growth in the limb following upon injuries to the lower epiphysis before the sixteenth year, and to the upper epiphysis before twenty. Since the greater part of the epiphyseal line is within the capsule, it follows that but little displacement, other than a slight movement backwards, is consequent upon the separation of the mass. Fractures of the olecranon are commonly due to direct violence, and in a few cases to severe indirect violence applied to the lower end of the humerus or upper end of the ulna. Instances of fracture by muscular action are few, and open to some question. The fracture is most commonly met with about the middle of the process, just where it begins to be constricted, and is usually transverse in direction. The amount of displace- ment effected by the triceps varies, and depends upon the extent to which the dense periosteum about the process and the ligaments that are attached to it are torn. The olecranon is de- veloped mainly from the shaft of the ulna (Fig. 57). There is a scale-like epiphysis, however, at the summit of the process which joins the rest of the olecranon at the age of seventeen. Occasion- ally another epiphyseal centre occurs, giving origin to the upper third of the olecranon (Fig. 57). In young subjects the scale-like epiphysis may be separated by violence, or the cartilagin- ous olecranon may be dissevered from the rest of the bone. The common fracture of the adult olecranon does not follow the epiphyseal line. Fracture of the coronoid process is an extremely rare accident, sometimes occurring in dislocation backwards of the ulna. It is impos sible to understand how the process can be torn off by the action of the brachialis anticus, as some XIII] EESECTION OF THE ELBOW 289 maintain, since that muscle is inserted rather into the ulna at the base of the projection than into the process itself (Fig. 57). Nor can it be separated as an epiphysis, as supposed by others, since it does not exist as such. Fractures of the head or neck ot the radius are rare, and occur usually with dislocation or other severe injury. The head is commonly found split or starred, and the lesion, if limited to the head, could hardly be diagnosed. The upper epiphysis of the radius is entirely within the limits of the annular ligament, and could scarcely be separated in a simple lesion. It is a mere disc of cartilage joining the shaft at the age of seven- teen. When the neck is broken the upper end of the lower fragment is drawn well forwards by the biceps muscle. Resection of the elbow may be performed in many ways. In all procedures there is danger of injuring the ulnar nerve, and some little difficulty often in clearing the prominent internal condyle. If the knife be kept close to the bone, no vessel of any magnitude should be divided. The muscles most disturbed are the triceps, anconeus, supin- ator brevis, extensor carpi ulnaris, extensor carpi radialis brevior, and brachialis anticus. It is most important to preserve the periosteum over the olecranon and the external lateral expansion of the triceps tendon to the deep fascia of the forearm, so that this muscle may still act as an extensor. It is never necessary to divide the insertion of the brachialis anticus, still less of the biceps, although some few fibres of the former muscle may be separated in removing the upper surface of the ulna. By the sub- periosteal method the periosteum is carefully peeled off from all the parts to be resected, and is preserved. By this means the triceps retains a hold upon the ulna, and the restoration of the joint is more complete. The functions of the joint may be well restored after resection, especially when performed by the subperiosteal 290 THE UPPER EXTREMITY [Chap. XIII method ; but it would appear that after no method are the anatomical details of the joint repro- duced. Thus, in a successful case, the new joint will assume the bimalleolar form, and will re- semble the ankle- rather than the elbow-joint. The humerus throws out two malleoli on the sites of the normal condyles, and in the concavity between them the ulna and radius are received. Between the ulna and the humerus new ligaments form, and a new annular ligament for the radius is also developed. Position of the main nerves at the elbow. — The musculo-spiral is found in front of the external epicondyle, under cover of the supinator longus, where it divides into posterior interos- seus and radial. The median is situated at the inner border of the brachial artery; the ulnar lies in a groove behind the internal epicondyle. CHAPTER XIV THE FOREARM Surface anatomy. — At its upper half, and especially in its upper third, the limb is much wider in its transverse than in its anteroposterior diameter. A horizontal section through this part will show a cut surface that is somewhat oval in outline, and is at the same time flattened in front and more convex behind. This outline is best seen in muscular subjects, and depends chiefly upon the development of the lateral masses of muscle that descend from the condyles. In the non-muscular, the limb, even in its highest parts, tends to assume a rounded rather than an oval outline. In women and children, also, the limb is round, owing to the comparatively slight de- velopment of the lateral muscular masses, and to the accumulation of fat on the front and back of the limb. The posterior surface of the forearm in a vigorous subject presents along its outer border a prominence formed by the supinator longus and the two radial extensors, which become tendinous below the centre of that border. On the lower third of this edge is a slight eminence, directed obliquely downwards, outwards, and for- wards, and due to the crossing of the extensors of the thumb. In the middle of the posterior surface is another elevation, running down from the outer condyle, and formed mainly by the extensor communis. To the inner side of this eminence is a groove, well seen in the very mus- 2t)l 292 THE UPPER EXTREMITY [Chap. cular, that indicates the posterior border of the ulna. The ulna is subcutaneous throughout its entire extent, and can be readily examined. The upper half of the radius is too deeply placed to be well made out, but the lower half of the bone can be easily felt beneath the skin. The course of the radial artery is represented by a line drawn from the outer border of the biceps tendon at the bend of the elbow to a point in front of the styloid process of the radius. The pulse is felt between the styloid process and tendon of the flexor carpi radialis where the artery rests on the lower ex- tremity of the radius. The middle and lower thirds of the ulnar artery follow a line from the inner condyle to the radial side of the pisi- form bone. The upper third would be repre- sented by a line drawn from the middle of the bend of the elbow to meet the first line at the junction of the upper and middle thirds of the inner border of the forearm. Such a line would be slightly curved, with its concavity outwards. The tendons, etc., that can be demonstrated at the lower extremity of the forearm will be considered in the description of the wrist. Vessels. — It is well to note the very free anas- tomoses that exist along the greater part of the limb between the ulnar and radial arteries. This fact was illustrated by a case under my care in the London Hospital. A seafaring man had inflicted upon his left forearm three deep transverse wounds across the front of the limb with a sharp knife. The wounds were about 1\ inches apart. The radial artery was divided in each of the wounds, and that vessel, therefore, presented six cut ends. It would appear to be sufficient to ligature the proximal and distal ends of the wounded vessel, and to leave the two iso- lated portions of the artery, each about lj inches in length, alone. I applied ligatures to five of the divided ends, leaving the lower end of thn upper isolated piece of the artery untied, and watched the effect. During the course of the day, XIV i THE FOREARM 293 when the man had rallied from the profound t'aintness due to the great loss of blood he had experienced, copious bleeding took place from this single unsecured end of the vessel, and it, of course, had also to be tied. There is a singular absence of large blood- vessels or nerves along the posterior aspect of the forearm, and it is significant that this is the aspect of the limb most exposed to injury. For a hand's-breadth below the olecranon there is almost an entire absence of superficial veins. The median nerve passes between the two heads of the pronator teres, and may possibly be compressed by that muscle when in vigorous action. At the wrist the median is between the tendons of the flexor carpi radialis and flexor sublimis digitorum; it lies deep to the tendon of the palmaris longus, which serves as a useful guide to its position. Bones ol the forearm. — Transverse sections of the limb at various levels show that the radius and ulna are in all parts nearer to the posterior than the anterior aspect of the ex- tremity (Figs. 59 and 60). This relation is the more marked the higher up the section. The two bones are nearest to the centre of the limb about the lower end of the middle third. At the upper part of the forearm the muscles are found mainly at the sides and in front. The lower the section proceeds down the limb, the less will the bones be covered at the sides, and the more equally will the soft parts be found distributed about the anterior and posterior aspects of the limb. It will be noticed that where one bone is the more substantial the other is the more slender, as near the elbow and wrist; and that it is about the centre of the limb that the two are most nearly of equal strength. The proximity of the two bones, and especially of the ulna, to the posterior aspect of the limb permits them to be easily examined from that surface, while it is from the same aspect that resections and other operations upon the 294 THE UPPER EXTREMITY [Chap. bones are most readily performed. It will be understood, moreover, that in compound frac- tures, due to penetration of fragments, the wound is more usually on the posterior aspect of the limb. The important movements of pronation and supination take place between these bones, and round an axis fy 2 corresponding to a line drawn through the head of the radius, the lower end of the ulna, and the metacarpal bone of the ring-finger. In extreme pro- nation the radius crosses the ulna obliquely ; the two bones are almost in contact at the point of crossing ; the lower fibres of the interosseus membrane and the posterior radio- ulnar ligament are tight. " The chief influ- ence in check- ing supination is not to be found in ligament at all, but in the contact of the posterior edge of the sig- moid cavity of the radius with the tendon of the extensor carpi ulnaris, as it lies in the groove between the styloid process and the round head of the ulna" (Sir H. Morris). Of the two movements, supination is section of the Fig. 59. — Transverse through the middle forearm. (Braune.) a, Badius ; b, ulna : c, supinator longus ; d, flexor longus pollicis : e, flexor carpi radialis : /, palmaris longus ; g, flexor sublimis digitorum ; h, flexor carpi ulnaris ; i, flexor pro- fundi s digitorum ; fc, extensor carpi ulnaris ; Z, extensor indicis : w, ex- tensor minimi digiti ; n, extensor communis digitorum ; o, extensor ossis and extensor secundi internodii pollicis ; q, extensor carpi radialis brevior ; r, extensor carpi radialis longior ; s, pronator radii teres; 1, radial vessels and nerve ; 2, ulnar vessels and nerve. XIV] THE FOREARM 295 the more powerful. This is illustrated in many ways. In using a screw-driver or a gimlet the movements of pronation and supination are conspicuously involved, but the main force is applied during supination. It is significant that the thread of a corkscrew is so turned that it shall be inserted by supination rather than by pronation. The only position in which the two bones are parallel to one another is the mid-position be- tween pronation and supination. It is in this posture only that the interosseous membrane is uncoiled throughout. Hence the selection of this position in the adjustment of most fractures of the forearm. The interosseous space is an ir- regular ellipse, a little larger below than above. It is narrowest in full pronation, widest in supination, and nearly as wide in the mid- position. It may be noted that the oblique ligament tends to resist forces that would drag the radius away from the humerus, and takes the place and the function of a direct ligament, passing from the humerus to the radius, while the interosseous membrane, from the obliquity of its fibres, makes the ulna take a share in the strain put upon the radius when that bone is forced upwards, as in resting on, or pushing with, the palm. Fractures of llie forearm. — The two bones are more often broken together than is either the radius or the ulna alone. The radius, when broken alone, is usually fractured by indirect violence, since it^ receives more or less entirely all shocks transmitted from the hand. The ulna, on the contrary, is more often broken by direct violence, it being the more superficial and exposed of the two bones. For example, in raising the arm to ward off a blow from the head, the ulna becomes uppermost. When the two bones are broken together, the violence may be direct or indirect. Malgaigne reports a case where both 296 THE UPPER EXTREMITY [Chap. holies in a patient were broken by muscular vio- lence when he was shovelling earth. Here the bones probably were broken between the two opposed forces represented by the biceps and brachialis anticus above and the weight of the loaded shovel in the hand below. When both bones are broken and the fractures are oblique, shortening may be produced by the united action of the flexors and extensors. The displacement varies greatly, and depends rather upon the direction of the violence than upon muscular action. Thus Hamilton says : " I have seen the fragments deviate slightly in almost every direction. " If union be delayed, the delay is usually in the radius, since it is the more mobile of the bones. When the radius alone is broken (1) between the insertions of the biceps and pronator teres, the upper fragment is flexed by the biceps and fully supinated by that muscle and the small supinator. The lower fragment will be pronated by the two pronators, and drawn in towards the ulna by means of these muscles. If such a fracture be put up with the hand midway between the prone and supine positions, the following evils result : the upper fragment is fully supinated by the muscles; the lower frag- ment is placed in the mid-position by the splints. It follows that the proper axis of the bone is not reproduced, and the use of the biceps and supinator brevis as supinators is entirely lost. Thus patients so treated usually recover with great loss in the power of supination; and to avoid this ill result, it is advised to put the limb up in full supination, so that the two frag- ments may unite in their proper axis, the upper fragment being supinated by the muscles, the lower by the splints. (2) When the fracture is between the insertions of the two pronators, the upper fragment may be carried a little forwards by the biceps and pronator teres, and drawn to- wards the ulna by the latter muscle. The lower fragment will be adducted to the ulna by the XIV] FRACTURES OF THE FOREARM 297 pronator quadratus, and its upper end will be still further tilted towards that bone by the action of the supinator longus upon the styloid process. When the ulna alone is broken, as, for example, about its middle, the upper fragment may be drawn a little forwards by the brachialis anticus, while the lower fragment will be carried towards the radius by the pronator quadratus. The displacement, however, in all cases is in- fluenced as much by the direction of the violence as by the action of muscles. When the fragments, after fracture of one or of both bones, fall in towards one another, so as to meet across the interosseous space, attempts are sometimes made to separate the broken ends and to preserve the integrity of the space by the use of graduated pads. These pads, however, if applied with sufficient force to separate the fragments, will probably compress one or both of the arteries of the limb, and cause great distress, resulting in a peculiar form of paralysis, due, it is believed, to the compression shutting off the blood-supply to the muscles. Subsequently the muscles undergo contracture. The fact that the bulk of the venous blood of the forearm is returned by surface veins may explain the ready occurrence of severe cedema in the limb when fractures are treated with im- properly applied splints or bandages. Since the arteries also can be readily affected by pressure, it follows that gangrene, as a result of improper treatment, is more common after fracture of the forearm than after fracture in any other part. Amputation of the forearm. — In amputa- tion of the forearm by double transfixion flaps, at about the upper part of the middle third the parts would be cut in the following manner (Fig. 59) : On the^ face of the anterior flap would be seen from without inwards the supinator longus (cut the whole length of the flap), then the flexor K # 298 THE UPPER EXTREMITY [Chap. sublimis (cut to a like extent), and, lastly, the flexor carpi ulnaris. Between the supinator longus and the flexor sublimis the divided end of the pronator teres is seen ; and between the flexor sublimis and the skin would lie the flexor carpi radialis and the palmaris longus. The latter would appear as a tendon at the inner border of the flap. In the angle between the two flaps would be found, in front of the radius, a little of the flexor longus pollicis, and in front of the ulna, the flexor profun- dus, the latter cut much the longer. Quite close to the radius, and for the most part behind it, would be the lowest part of the small supin- ator, while behind the ulna would be the cut fibres of the upper end of the extensor ossis. On the face of the posterior flap would be seen from without inwards the extensor carpi radialis longior and brevior, the ex- tensor communis, the extensor of the little ]l o Fig. 60. — Transverse section through the lower third of the forearm. {Braune.) a, Radius ; b, ulna ; c, supinator longus ; d, flexor longus pol- licis ; e, flexor carpi radialis ; /, palmaris longus ; f/, flexor sublimis digitorum ; h, flexor carpi ulnaris ; i, flexor pro- fundus digitorum ;j, pronato quadratus ; k. extensor carpi ulnaris ; I, extensor indicis ; m, extensor minimi digiti ; n, extensor communis digi- torum ; o, extensor secundi internodii pollicis ; p, exten- sor primi internodii pollicis : q, extensor carpi radialis brevior ; r, extensor carpi radialis longior, with, in front of it, the extensor ossis meta- carpi pollicis ; 1, radial vessels ; 2, ulnar vessels ; 3, median nerve. finger, and the extensor carpi ulnaris. The radial artery will run the whole length of the anterior flap, and be cut near its outer border to the inner side of the supinator longus. The ulnar artery will be cut shorter, in front of the bone, and between the flexor sublimis and flexor profundus. The XIV] AMPUTATION OF THE FOREABM 299 anterior interosseous vessels will be divided im- mediately in front of the interosseous membrane. The posterior interosseous vessels will be cut long, and will be found between the superficial and deep muscles. Fig. 60 shows the relation of the parts as they would be cut in a circular amputation of the limb through the lower third. CHAPTER XV THE WRIST AND HAND Surface anatomy. — The following structures can be made out about the wrist : Commencing at the outer side, the lower extremity and styloid process of the radius can be well defined. The bone is here superficial in front and behind. The styloid process lies more anteriorly than does the corresponding process of the ulna, and also de- scends about | an inch lower down the limb. The outer surface of the radius at the wrist is crossed by the tendons of the extensor ossis meta- carpi and extensor brevis pollicis. These are very distinct when the thumb is abducted, and the slit- like interval between the two can be felt. About the centre of the front of the wrist is the pal- maris longus tendon, which is usually the most- conspicuous of the tendons on this aspect of the joint. It will be found absent in quite 10 per cent, of wrists examined. It is rendered most prominent when the wrist is a little flexed, the fingers and thumbs extended, and the thenar and hypothenar eminences as much approximated as possible. A little to its outer side is the larger but less prominent tendon of the flexor carpi radialis. In the narrow groove between these two tendons lies the median nerve, and on the radial side of the flexor carpi radialis is the radial artery. * Sometimes the superficial is volae arises higher and is larger than usmal. It then runs by the tide of the radial in front of the wrist, and, giving additional volume to the pulse, has been the foundation of the go-called "double pulse." 300 Chap. XV] SURFACE ANATOMY OF WRIST 301 The venae comites surround the artery, and when distended alter the character of the pulse (Hill). Towards the inner border of the wrist the flexor carpi ulnaris tendon is evident, descending to the pisiform bone. It is rendered most distinct when the wrist is slightly flexed and the little finger pressed forcibly into the palm. In the hollow which this posture produces between the last-named tendon and the palmaris longus lie the flexor sublimis tendons, and just to the radial side of the flexor carpi ulnaris the pulsations of the ulnar artery can be felt. Beneath the thin skin in front of the wrist a part of the plexus of veins can be seen that end in the median and anterior ulnar trunks. The ulnar nerve grooves the radial side of the pisiform bone. At the back of the wrist the following tendons can be readily distinguished from without inwards (Fig. 62) : the extensor longus pollicis (extensor secundi internodii), the extensor communis, and the extensor carpi ulnaris. Of these, the most prominent is the first-named. It is rendered ! most distinct when the thumb is forcibly abducted ! and extended. The tendon leads up to a small ! but prominent bony elevation on the back of i the radius that marks the outer border of the J osseous groove for its reception. This tendon, j when it reaches the radius, points to the centre ! of the posterior surface of that bone, and also 1 indicates roughly the position of the interval between the scaphoid and semilunar bones. The lower end of the ulna is very distinct. When the hand is supine, its styloid process is exposed at the inner and posterior aspect of the wrist to the inner side of the extensor carpi ulnaris. In pronation, however, the process is rendered less distinct, while the head projects prominently on the posterior part of the wrist, and is found to lie between the tendons of the extensor carpi ulnaris and extensor minimi digiti. Wrist-joint.— The tip of the styloid process of the ulna corresponds to the line of the wrist- 302 THE UPPER EXTREMITY [Chap. joint, and a knife entered below that point would enter the articulation. A knife entered horizontally just below the tip of the styloid pro- cess of the radius would hit the scaphoid bone. A line drawn between the two styloid processes would slope downwards and outwards, its two extremities would represent the extreme inferior limits of the radio-carpal joint, and would fairly correspond to the chord of the arc formed by the line of that joint. The line between the styloid processes would be nearly | an inch below the summit of the arch of the wrist-joint. There are several folds in the skin on the front of the wrist; of these, the lowest is the most dis- tinct. It is a little convex downwards, precisely crosses the neck of the os magnum in the line of the third metacarpal bone (Tillaux), and is not quite f of an inch below the arch of the wrist joint. It is about J an inch above the carpo- metacarpal joint, and indicates very fairly the upper border of the anterior annular ligament (Fig. 65). Palmar surface of the hand. — The palm is con- cave in the centre where the skin is adherent to the palmar fascia. This " hollow of the hand" is of somewhat triangular outline, with the apex upwards. On either side are the thenar and hypo- thenar eminences. At the upper end of the former eminence, a bony projection is felt, just below and internally to the radial styloid process, which is formed by the tubercle of the scaphoid and ridge on the trapezium (Fig. 65). The interval separat- ing these two processes of bone cannot always be made out. At the upper extremity of the hypo- thenar eminence is the projection of the pisiform bone, and just below it the unciform process can be identified. Below the hollow of the palm, and opposite the clefts between the four fingers, three little elevations are seen, especially when the first phalanges are extended, and the second and third are flexed. These correspond to the fatty tissue between the flexor tendons and the digital slips XV] PALMAR SURFACE OF HAND 303 of the palmar fascia. The grooves that may be seen to separate the elevations correspond to those slips. Of the creases in the shin of the palm (Fig. 61), three require especial notice. The first starts at the wrist, between the thenar and hypothenar eminences, and, marking off the former eminence from the palm, ends at the outer border of the hand at the base of the index finger. The second fold is slightly marked. It starts from the outer border of the hand, where the first fold ends. It runs obliquely inwards across the palm with a marked inclination towards the wrist, and ends at the outer limit of the hypothenar eminence. The third, lowest, and best-marked of the folds starts from the little elevation opposite the cleft between the index and middle fingers, and runs nearly transversely to the ulnar border of the hand, crossing the hypothenar eminence at the upper end of its lower fourth. An unimportant crease running obliquely from the third to the second fold gives to these markings the outline of the letter M. The first fold is produced by the opposition of the thumb, the second mainly by the bending simultaneously of the metacarpo- phalangeal joints of the first and second fingers, and the third by the flexion of the three inner fingers. The second fold, as it crosses the third metacarpal bone, corresponds approximately to the lowest point of the superficial palmar arch (Fig. 61). The third fold crosses the necks of the metacarpal bones, and indicates pretty nearly the upper limits of the synovial sheaths for the flexor tendons of the three outer fingers (Fig. 65). A little way below this fold the palmar fascia breaks up into its four slips, and midway between the fold and the webs of the fingers lie the metacarpo-phalangeal joints. Of the transverse folds across the fronts of the fingers corresponding to the metacarpo-phalangeal and interphalangeal joints, the highest is single for the index and little finger and double for the other two. It is placed nearly f of an inch below 304 THE UPPER EXTREMITY [Chap. the corresponding joint. The middle folds are double for all the fingers, and are exactly oppo- Fig. 61. — Surface markings on the palm of the hand. The thick black lines represent the chief creases on the skin. site the proximal interphalangeal joints. The distal creases are single, and are placed a little above the corresponding joints (1 to 2 mm., ac- XV] SURFACE OF THE HAND 305 cording to Paulet). There are two single creases on the thumb corresponding to the two joints, the higher crossing the metacarpophalangeal articulation obliquely. The free edge of the web of the fingers, as measured from the palmar sur- face, is about | of an inch from the metacarpo- phalangeal joints. The superficial palmar arch may be represented by a curved line across the palm starting from the pisiform bone and run- ning in a line with the palmar border of the thumb when outstretched at right angles with the index finger. The deep arch is between \ and \ an inch nearer the wrist, and its position may be accurately marked by a line drawn from the base of the fifth metacarpal to the base of the second, two easily distinguished points. The digital arteries bifurcate about \ an inch above the clefts between the fingers (Fig. 61). Dorsal surface of the hand. — On the outer side of the wrist, when the thumb is extended, a hollow is obvious between the extensores ossis metacarpi and brevis pollicis and the extensor longus pol- licis. French writers have termed this hollow "tabatiere anatomique " (Fig. 62). Across this hollow and beneath the tendons just named runs the radial artery. Under the skin over the space can usually be seen a large vein, the cephalic vein of the thumb. Across the space also runs the external division of the terminal branch of the radial nerve. In the floor of the " snuff-box" are the scaphoid bone and the trapezium. The extensor longus pollicis crosses the apex of the first interosseous space. The sesamoid bones of the thumb and the joint between the trapezium and the first metacarpal bone can all be well made out. The latter articulation is situate in the floor of the " tabatiere." On the back of the hand the various tendons and the surface veins, too, can all be clearly distinguished. Between the first and second metacarpal bones is the first dorsal interosseous muscle, which forms a con- spicuous prominence when the thumb is pressed 306 THE tJPPEK EXTEEMITY [Chap. against the side of the index finger. The three rows of knuckles are formed by the proximal bones of the several joints. The skin of the palm and of the front of the fingers is thick and dense, while that on the back of the hand is much finer. The palm, the fronts and sides of the fingers, and the Articular (Ulna) Styloid (Ulna) Semilunar Cuneiform BASE OF 5TH Metacarp. Ext. Prop- Poll. Styloid (radius) radial Ridge Scaphoid Radial Art. Os Magnum (Head) Trapezium Fig. 62. — Chief surface markings on the dorsal aspect of the wrist. dorsal aspects of the last phalanges, all show an entire absence of hair and of sebaceous glands. These parts are, therefore, exempt from the maladies that attack hair-follicles and their gland appendages. On the dorsum of the hand, and of the first and second rows of phalanges, there are numerous hairs and sebaceous follicles. Sweat-glands are more numerous in the skin of the palm than in any other part. According to XV] SKIN OF THE HAND 307 Sappey they are four times more numerous here than they are elsewhere. Krause has estimated that nearly 2^800 of these glands open upon a square inch of the palm. Only about half the number are found upon the dorsum of the hand. The profuseness with which the palm may per- spire is well known, and is very marked in certain conditions. The cutaneous nerve-supply of the hand is very free. The nerves present Pacinian bodies, which are far more numerous in the hand than in any other part. With the exception of the tip of the tongue, a more acute degree of tactile sensibility is met with in the hand than elsewhere in the body. The most sensitive district is the palmar surface of the third phalanx of the index finger, while the least sensitive to tactile im- pressions is the dorsum of the hand. It may be said that the tips of the fingers are about thirty times more acute to the sense of touch than is the skin of the middle of the forearm, which is among the least sensitive portions of the integument as regards tactile influences. The subcutaneous tissue of the front of the hand, and especially of the palm, is scanty and dense, and somewhat resembles the subcutaneous tissue of the scalp in that the skin is closely ad- herent to it, and the fat it contains is arranged in minute lobules lodged in lacunae. Cutaneous ligaments bind the skin down at the creases of the palm and fingers. The subcutaneous tissue on the dorsum, however, is lax, and has but a frail association with the skin. Thus it follows that subcutaneous extravasations of blood are practically impossible in the palm and on the anterior aspect of the fingers, while they may be very extensive on the dorsum. In like manner oedema of the extremity is conspicuously marked upon the dorsal surface, while the palm remains comparatively free even in severe cases. The denseness of the integuments of the palm renders inflammation of g the part extremely painful, owing to the tension that is so readily produced, 308 THE UPPER EXTREMITY [Chap. whereas inflammation in the lax tissues of the dorsum may reach some magnitude without caus- ing great pain. The palm of the hand is well adapted to meet the effects of pressure and fric- tion. The cuticle is thick, the skin is adherent, and immediately beneath it lies the dense palmar fascia. This fascia efficiently protects the palmar nerves and the main vessels, while it must be noted that the front of the hand, and especially the palm, is singularly free from surface veins. Indeed, the great bulk of the blood from the hand is returned by the superficial veins on the dorsum of the fingers and hand. In like manner, the lymphatics of the palm, which form a rich sub- cutaneous plexus, join the large efferent lym- phatics on the dorsum of the hand. The form of the nail varies somewhat in in- dividuals, and, according to certain authors, there are special types of nail to be met with in some constitutional diseases. By the Hippocratic hand is meant a hand the tips of the fingers of which are clubbed and the nails of which are much curved. This condition would appear to be due to impeded circulation by retardation in the return of venous blood, and perhaps also to im- perfect oxygenation of that blood. It is most often met with in congenital heart disease, in phthisis, empyema, chronic lung affections, and certain thoracic aneurysms. There are several forms of inflammation affecting the matrix of the nail and the soft parts immediately around it (onychia, paronychia). Such inflammations lead to great deformity of the structure itself. When a nail is thrown off by suppuration or violence a new nail is produced, provided any of the deeper epithelial cells are left. During conval- escence from certain illnesses (e.g. scarlet fever), a transverse groove will appear across all the nails. This groove indicates the portion of nail formed during the illness, and by watching its movement the rate of growth of the nail can be estimated. The nail grows at the average rate of XV] PALMAR FASCIA 309 sVnd of an inch per week; if the hand is im- mobilized by splints the rate of growth is retarded. (Head.) It may be noted that each digital nerve gives a special branch of large size to the pulp beneath the nail, and this explains the intense pain felt when a foreign body is thrust under the nail. The fasciae.— Beneath the skin of the palm is the dense palmar fascia. This fascia gives almost as much strength to the hand as would so much bone, while its unyielding character, its com- parative freedom from vessels and nerves, render it well suited to withstand the effects of pressure. The fascia gives slips to each finger ; each slip sends fibres to join the digital sheaths of the tendons, the skin, and the superficial transverse ligament. In the disease known as Dupuytren's contraction, the palmar fascia, and especially its digital slips, becomes contracted. One or more or all of the fingers may be involved in the con- traction. The proximal phalanx is drawn or flexed towards the palm, and later the second phalanx becomes bent. The skin is drawn in towards the fascia, since the two structures are normally connected with one another. Experi- ment shows that by dragging upon the fascia the proximal phalanx can be readily bent, and also, but with less ease, the middle phalanx. The middle part of the palmar fascia represents the tendon of the palmaris longus in the hand. The structures of the palm are divided into three spaces by the fascia (Fig. 63). Thus the muscles of the thenar and hypothenar eminences are both enclosed in a thin fascia proper to each. The two spaces formed by these membranes are enclosed in all directions, and are capable, though only in a feeble way, of limiting suppuration when it commences in them. Between these two spaces is a third space, which is roofed in by the palmar fascia. This cavity is closed in at the sides, but is open above and below. Above there is a free opening beneath the annular ligament 310 THE UPPER EXTREMITY TChap. and along the flexor tendons into the forearm, while below there are the seven passages provided for by the division of the palmar fascia. Of these seven passages, four, situate at the roots of the several fingers, give passage to the flexor tendons, while the remaining three correspond to the webs between the fingers, and give passage to the lum- Fig. 63. — Horizontal section of the hand through the middle of the thenar and hypothenar eminences. (Tillaux.) a, Metacarpal bone ; b, first dorsal interosseous ; c, palmaris brevis d, abductor min. digiti ; e, flexor brevis min. dig. : /, opponens min. dig. ; g, flexor brevis poll. ; h, abductor poll. ; /, opponens poll. ; j, adductor poll. ; k, flexor long poll. ; /, dorsal interossei ; m, palmar interossei ; », flexor sublimis ; o, flexor profundus ; p, superflc. vola) ; q, median nerve, and (on inner side) ulnar artery and nerve ; r, deep palmar arch ; 1, palmar fascia ; 2, outer septum ; 3 inner septum ; 4, deep fascia of palm. bricales and the digital vessels and nerves. When pus, therefore, forms on the palm, beneath the palmar fascia, it cannot come forward through that dense membrane, but escapes rather along the fingers or makes its way up into the forearm. So rigid is the resistance offered by the palmar fascia, that pent-up pus will make its way through the interosseous spaces and appear on the dorsum of the hand, rather than come through the cover- ings of the palm. XV] TENDONS OF THE WRIST 311 In opening a palmar abscess, when it points above the wrist, the incision should be in the long axis of the forearm, should be above the annular ligament, and is most conveniently made a little to the ulnar side of the palmaris longus, for a cut in this position would escape both the ulnar and radial arteries and also the median nerve. The tendons about the wrist are bound down and held in place by the annular ligaments. So dense is the anterior ligament, that even in ex- tensive abscess of the palm reaching into the forearm, and in severe i a distension of the synovial sheaths beneath the ligament, it remains firm, and will not yield. The lower border of the posterior annular liga- ment corresponds. to the upper edge of the anterior band, and these structures together act the part of the leather bracelet that the labourer sometimes wears around his wrist," and that, in fact, takes the function of an additional annular ligament. The fibrous sheaths for the flexor tendons extend from the metacarpo- phalangeal joints to the upper ends of the distal phalanges. The pulp of the third phalanx, therefore, rests practically upon the periosteum. Opposite the finger-joints the sheaths are lax and thin, and spaces may occur between the decussating fibres of the sheaths, through which the synovial mem- brane lining the sheath may protrude. It is, I believe, through this less protected part of the sheath that external suppuration often finds its way into the interior of the sheath. The sheaths in the rest of their course are dense and rigid, and whan cut across remain wide open (Fig. 64). Thus, after the division of the sheath, as in amputation, an open channel is left leading into the palm of the hand, and offering the greatest Fig. 64.— Ho- rizontal sec- tion through middle of second pha- lanx. {Til- la ux.) a, Flexor ten- don; b, fibrous sheath of ten- don ; c, exten- sor tendon ; d digital artery and nerve. 312 THE UPPER EXTREMITY [Chap. facility for the spread of pus into that part. It is this rigidly open fibrous sheath that probably may explain the frequency of suppuration in the palm after amputation of a part of a finger, and I am decidedly of opinion that some steps should be taken to protect or shut off this channel in any case where the sheath has been accidentally or intentionally divided. The tendons accurately fill the fibrous sheaths. A gangliform growth on the tendon as it enters the sheath, or a constriction of the sheath with an inequality in the tendon, gives rise to the con- dition known as •' snap '[ finger. Such a digit cannot be extended by will, but when pushed a little way " springs back with a snap like the blade of a pocket knife " (Abbe). " Congenital contraction ' ' of the little finger is very common in a slight degree. In marked cases, the prox- imal phalanx is hyperextended and the middle flexed. Lockwood found in such a case that the condition was due to a contraction in the fibrous sheath in front of the joint. Contracted finger following whitlow is due to an adhesion of the tendons to their sheath. Paralytic contraction of the flexor muscles also brings about permanent contracture of the fingers. Synovial sacs and sheaths.— There are two synovial sacs beneath the annular ligament for the flexor tendons, one for the flexor longus pollicis, the other for the flexor sublimis and profundus tendons (Fig. 65). The former extends up into the forearm for about ij inches above the annular ligament, and follows its tendon to its insertion in the last phalanx of the thumb. The latter rises about lh inches above the annular band, and ends in diverticula for the four fingers. The process for the little finger usually extends to the insertion of the flexor profundus tendon in tKe last phalanx. The remaining three diverticula end about the middle of the corresponding meta- carpal bones. The synovial sheaths for the digital part of the tendons to the index, middle, and ring XVI SYNOVIAL SACS OF WBIST 313 fingers end above about the neck of the meta- carpal bones, and are thus separated by about \ to \ an inch from the great synovial sac beneath the annular ligament. Thus there is an open channel from the ends of the thumb and little finger to a point in the forearm some \\ inches Flexor Diqitorum Unciform Pisiform Wrist Folds Styloid Process Flex. Longus Pollicis Trapezium Ant. Annular Ligavent scaphoid flexor Carp. Radialis styloid Process Fig. 65. — Anterior annular ligament of the wrist, and synovial sheaths of the wrist and hand. The creases of the hand are indicated by black lines ; the synovial sheaths are shown in red. above the annular ligament. The arrangement explains the well-known surgical fact that ab- scesses of .the thumb and little finger are apt to be followed by t abscesses in the forearm, while such a complication is not usual after suppuration in the remaining fingers. The synovial sac for the flexor tendons is narrowed as it passes beneath the annular ligament, and thus it happens that 314 THE TIPPER EXTREMITY [Chap. when distended with fluid or with pus, it presents an hour-glass outline, the waist of the hour-glass corresponding to the ligament. The two synovial sacs beneath the ligament sometimes communicate with one another. The tendon of the flexor carpi radialis perforates the insertion of the annular ligament to the trapezium ; it is surrounded by a synovial sheath (Fig. 65). In one form of whitlow, that form where the pus occupies the synovial sheaths of the tendons on the fingers (thecal abscess), the suppuration can often be seen to end abruptly where the sheath ends, when the index, middle, or ring finger is involved, viz. opposite the neck of the corre- sponding metacarpal bones. In another form of whitlow (the abscess in the pulp at the end of the finger) the periosteum of the third phalanx is readily attacked, there being no intervening ten- don sheath over that bone. In this affection the bone often necroses and comes away, but it significant to note that it is very seldom that the whole of the phalanx perishes. The upper part, or base, of the bone usually remains sound, and is probably preserved by the insertion of the flexor profundus tendon. The base of the bone is an epiphysis that does not unite to the shaft until the eighteenth or twentieth year. The tendons do not lie free within the sac, but are bound to it by folds of synovial membrane in much the same way as the bowel is bound to the abdominal parietes by its mesentery. These folds may be ruptured in severe sprains, when the nutrient vessels for the tendon, which are con- tained in them, may be torn. Eupture is followec by effusion into the sac. These folds are almost absent within the digital sheaths, the slight liga- menta longa and brevia, near the insertion oi the tendons, being their sole representatives. Syn- ovial sacs are lined by a squamous epithelium, anc have extremely free communication with the lym- phatic vessels of the part. Hence the f ree^ absorp- tion of infective matter from such cavities. XV] SYNOVIAL SHEATHS OF WRIST 3l5 Beneath the posterior annular ligament there are six synovial sheaths for tendons, correspond- ing to the six canals formed by that ligament. The sheath most frequently inflamed is that for the extensores ossi metacarpi and brevis pollicis. It runs from a point about } of an inch above the radial styloid process to the first carpo-meta- carpal joint. The other sheaths reach above to the upper border of the annular ligament, that for the two radial extensors, however, beginning about \ an inch above the ligament. The sheaths for the extensor communis and the extensor minimi digiti extend below to the middle of the metacarpus; that for the extensor indicis barely reaches the metacarpus. The other sheaths follow the tendons to their insertions. The synovial lin- ing and folds of these sheaths are injured in Colles' fracture of the radius. The tendons be- come adherent and fixed to their sheaths unless this be prevented by passive movements of the tendons. Blood-vessels and lymplmfies*— The hand is very well supplied with blood, and indeed the finger pulp is one of the most vascular parts in the body. Cases are recorded where the tip of the finger has been accidentally cut off, and has grown again to the limb on being immediately reapplied. The position of the palmar arches has been pointed out. It is well known that haemorrhage from either of the palmar arches can- not be checked by ligature of the radial or ulnar artery alone, on account of the connexion of the arches with those vessels; and it is also known that simultaneous ligation of the two vessels may have no better effect, owing to the anastomoses between the palmar arches and the interosseous vessels. The anastomosis between the two palmar arches is well known, and is freely established both by the main vessels themselves and by the communion that exists between the digital arteries from the superficial arch and the palmar inter- osseous branches from the deeper vessels. In 316 THE UPPER EXTREMITY [Chap. bleeding from the palm, the simultaneous ligature of the radial and ulnar arteries may also entirely fail in those cases where the arches are freely joined, or are more or less replaced by large and abnormal interosseous vessels, or by a large tk median " artery. When either the radial or the ulnar part of the arches is defective, the lack is usually supplied by the other vessel ; and it is well to note that the deficiency is most common in the superficial or ulnar arch. Pressure ap- plied to the palm to arrest bleeding is apt to cause gangrene, owing to the rigidity of the parts and the ease with which considerable pressure can be applied. The radial artery, as it curves round the back of the hand to reach the deeper part of the palm, is in close contact with the carpo-metacarpal joint of the thumb (Fig. 62). This fact must be borne in mind in amputation of the entire thumb, and also in resection of the first metacarpal bone. The superficialis volae, if large, may bleed seri- ously. It adheres to the surface of the annular ligament, and may therefore be difficult to pick up when wounded. From the larger size and great number of the lymphatics about the fingers and on the dorsum of the hand, it follows that lymphangitis is more common after wounds of those parts than it is after wounds of the palm. Bones and joints. — The inferior radio-ulnar joint is supported by the powerful triangular fibro-cartilage, which forms the strongest and most important of all the ligamentous connexions between the two bones. The synovial sheath of the extensor minimi digiti sometimes communi- cates with this joint, and may therefore be involved when that articulation is diseased. The strength of the wrist-joint depends not so much upon its mechanical outline or its liga- ments as upon the numerous strong tendons that surround it, and that are so closely bound down to the bones about the articulation. Moreover, in XVI MOVEMENTS AT THE WRIST 317 the case of the wrist the long lever does not exist on the distal side of the joint. The anterior liga- ment of the wrist is the strongest ligament of the joint, while the posterior is the weakest. The former structure limits extension, and the latter flexion ; and in connexion with this arrangement it is interesting to note that injury from forced extension is more common than from forced flexion. Thus, when a man falls upon the hand, he more usually falls upon the palm (forced ex- tension) than upon the dorsum (forced flexion). Owing to the thinness of the posterior ligament, together with the more superficial position of the hinder part of the joint, it follows that the effu- sion in wrist-joint disease is first noticed at the back of the hand. Movements at the wrist take place as freely in the intercarpal joint (between the first and second row of carpal bones) as in the radio-carpal joint (Fig. 62). The axis of the radio-carpal joint is such that in flexion the palm turns towards the ulnar side of the forearm; while in flexion at the mid-carpal joint the palm moves towards the radial side. When movement takes place at both joints these tendencies are balanced and pure flexion is produced. The tendon of the extensor carpi ulnaris is placed anteriorly to the axis of the mid-carpal joint, but behind the radio-carpal, and therefore produces flexion in one joint and exten- sion in the other (Ashdowne). The muscles which act on the wrist exemplify the various parts which muscles play in producing a purposeful move- ment. A muscle may act as (1) a prime mover, (2) an antagonist, (3) a synergic muscle, (4) a fixation muscle. For instance, when the fingers are flexed : the deep and superficial flexors are the prime movers ; the antagonists in action are the exten- sors of the fingers ; the flexors of the fingers would also produce flexion at the wrist were not the ex- tensors of the wrist also thrown into action as synergic muscles ; when the extensors of the fingers act, the flexors of the wrist contract; in flexing 318 THE UPPER EXTREMITY [Chap. and extending the fingers the wrist can be rem dered immovable by the flexors and extensors of the carpus, which then act as muscles of fixation. Thus a movement which appears simple results from the action of groups of muscles, and it is this complexity which makes the diagnosis of nerve lesions from a study of the action of mus- cles so difficult. What has been said of the muscles of the wrist applies equally to all the muscles of the body. {See Beevor's Croonian Lectures, 1903.) But little movement is allowed in the carpo- metacarpal joints of the first three fingers, but in the like joints of the thumb and little finger movements are free, and their preservation is of great importance to the general usefulness of the hand. The glenoid ligaments in front of the three finger-joints are firmly attached to the distal bone, and but loosely to the proximal. Thus it happens that in dislocation of the distal bone backwards, the glenoid ligament is carried with it, and offers a great obstacle to reduction. In flexing the middle and distal phalanges alone, it will be seen that the proximal phalanx is steadied by the extensor tendon as a preliminary measure ; and in paralysis of the extensors, flexion of these two joints alone is not possible. Very few persons have the power of flexing the last finger-joint without at the same time bending the articulation above it; but in certain inflam- matory affections about the last phalanges the terminal joint is sometimes seen to be fixed in a flexed posture while the other finger-joints are straight. In the condition known as " mallet " finger the distal phalanx is fixed in a flexed posi- tion. The condition is due to a partial or com- plete rupture of the extensor tendon of the finger, commonly the result of a blow over the terminal knuckles. Colles' fracture. — This name is given to a trans- verse fracture through the lower end of the radius, from J to 1 inch above the wrist-joint (Fig. 66). XV] COLLES' FRACTURE 319 It is associated with a certain definite deformity, and is always the result of indirect violence, a fall upon the outstretched hand. There are good reasons why the bone should break in this situa- tion. The lower end of the radius is very can- cellous, while the shaft contains a good deal of compact bone. At about j of an inch from the articular surface these two parts of the bone meet, jFRACTURED STYLOID Fractured Scaphoid Fig. 66. — Diagram showing the situation of Colles' fracture of the radius, with fracture of the styloid of the ulna. The usual position of a fracture of the scaphoid is also indicated. and their very unequal density greatly tends to localize the fracture in this situation. As to the mechanism of this lesion, many different opinions are still held, and a vast deal has been written on the subject. I subjoin Professor Chiene's ac- count of this lesion, because it may be taken as representing with admirable clearness the views most generally accepted at the present time as to the nature of this injury. Into the discussion Kself I do not propose to enter. The deformity 320 THE UPPER EXTREMITY [Chap. in Colles' fracture is entirely due to the displace- ment of the lower fragment. u The displacement is a triple one : (a) backwards, as regards the anteroposterior diameter of the forearm ; (b) rotation backwards of the carpal surface on the transverse diameter of the forearm ; (e) rotation through the arc of a circle, the centre of which is situated at the ulnar attachment of the triangular ligament, the radius of the circle being a line from the ulnar attachment of the triangular ligament to the tip of the styloid process of the radius. (•/) When a person in falling puts out his hand to save himself, at the moment the hand reaches the ground the force is received principally by the ball of the thumb, and passes into the carpus, and thence into the lower end of the radius. If, at the moment of impact, the angle between the axis of the forearm and the ground is less than 60°, the line representing the direction of the force passes upwards in front of the axis of the forearm ; the whole shock is therefore borne by the lower end of the radius, which is broken off, and, the force being continued, the lower fragment is driven backwards. When at the moment of impact the angle is greater than 60°, the line of the force, instead of passing in front of Che axis of the arm, passes up the arm, and the usual result is either a severe sprain of the wrist or a dislocation of the bones of the forearm backwards at the elbow- joint, (b) The carpal surface of the radius slopes forwards, and therefore the posterior edge of the bone receives the greater part of the shock ; there is, as a result, rotation of the lower fragment backwards on the transverse diameter of the forearm, (c) The carpal surface of the radius slopes downwards and outwards to the radial edge of the arm ; therefore the radial edge of the bone receives the principal part of the shock through the ball of the thumb. As a result, this edge of the lower fragment is displaced upwards to a greater extent than the ulnar edge of the fragment, which remains firmly attached to the ulna by the triangular ligament." In over 50 per cent, of cases, the styloid process of the ulna is also broken by the force transmitted to it through the triangular fibro-cartilage (Mor- ton). By means of this rotatory displacement, the tips of the two styloid processes come to occupy the same level, or the radial process may even mount above the ulnar. In nearly every case there is XV] COLLES' FRACTURE 321 some penetration of the fragments, the compact tissue on the dorsal aspect of the upper fragment being driven (by a continuation of the force that broke the bone) into the cancellous tissue on the palmar aspect of the lower fragment. It is only in very rare instances that the fragments are so separated as to ride the one over the other. In such cases the radio-ulnar ligaments are probably ruptured, and the wrist ceases to present the typi- cal deformity of a Colles' fracture. In studying the radiographs of 170 cases diagnosed as Colles' fracture, Dr. R. Morton found there was disloca- tion as well as fracture in 3 and separation of the lower radial epiphysis in 11 cases. This epiphysis is often separated by accidental vio- lence. It joins the shaft about the twentieth year. Its junction with the shaft is represented by a nearly horizontal line, and the epiphysis includes the facet for the ulna and the insertion of the supinator longus. Since the introduction of radiographic methods of examination, it has been found that many in- juries, formerly regarded as mere sprains, were really due to fracture or displacement of carpal bones or fracture of a metacarpal. Fracture of the scaphoid occurs as the result of falls on the outstretched palm, or by direct violence. It lies in the floor of the "snuff- box," and may be palpated there. The semilunar is most frequently displaced, and of the meta- carpal bones the fifth is most frequently fractured. Dislocations. 1. At the wrist-joint.— So strong is this articulation, for the reasons above given, that carpo-radial luxations are extremely rare. For the same reasons, when they do occur they are usually complicated, and are associated with tearing of the skin, or rupture of tendons, or fractures of the adjacent bones. The luxations of the carpus may be either backwards or forwards, the latter being extremely rare. They would appear to be produced with equal ease by a fall upon either the front or the back of the hand. 322 THE UPPER EXTREMITY [Chap. Bransby Cooper gives the case of a lad who fell upon the outstretched palms of both his hands : both wrists were dislocated, one backwards, the other forwards. There are five articular synovial cavities con- nected with the carpus. They occur in the follow- ing situations : (a) Between the carpus and fore- arm bones; it may communicate with the lower radio-ulnar cavity through the triangular fibro- cartilage ; (h) between the unciform and the fourth and fifth metacarpals; (c) between the metacarpal of the thumb and trapezium; (d) between all the carpal bones and extending to the carpo-metacarpal joints of the second and third digits; (e) between the pisiform and cuneiform bones. Hernial protrusions and gangliform growths from these synovial membranes are fre- quently seen on the dorsum of the carpus. 2. Dislocation of the os magnum. — In forcible flexion of the hand, the os magnum naturally glides backwards and projects upon the dorsum. In very extreme flexion (as in falls upon the knuckles and dorsum of the metacarpus), this movement of the bone backwards may be such asto lead to its partial dislocation, the # luxation being associated with some rupture of ligaments. In one recorded case this luxation was produced by muscular force. The patient, a lady, while in labour, "seized violently the edge of her mattress, and squeezed^ it forcibly." Something was felt to give way in the hand, and the head of the os magnum was found to be dislocated backwards. 3. Dislocations at the metacarpophalangeal joint of the thumb. — In this luxation the phalanx is usually displaced backwards, and the lesion is of interest on account of the great difficulty often experienced in reducing the bone. Many ana- tomical reasons have been given to explain this difficulty — these are well summarized by Hamil- ton in the following passage : " Hey believes the resistance ^ to be in the lateral ligaments, be- tween which the lower end of the metacarpal XV AVULSION OF FINGERS 323 bone escapes and becomes imprisoned. Ballingall, Malgaigne, Erichsen, and Vidal think the meta- carpal bone is locked between the two heads of the flexor brevis, or, rather, between the oppos- ing sets of muscles which centre in the sesamoid bones, as a button is fastened into a button-hole. Pailloux and others affirm that the anterior liga- ment, being torn from one of its attachments, falls between the joint surfaces, and thus inter- poses an effectual obstacle to reduction. Lisfranc found in an ancient luxation the tendon of the long flexor so displaced inwards, and entangled behind the extremity of the bone, as to prevent reduction." Mr. Jonathan Hutchinson has in- vestigated several cases and found that reduc- tion is prevented by the fibrocartilaginous plate on the palmar aspect of the joint. The plate is firmly attached to the phalanx and is dis- located with it. When subcutaneously divided from the extensor aspect of the thumb, the dis- location may be reduced with ease. Avulsion of one or more fingers may be effected by severe violence. In such cases the finger torn off usually takes with it some or all of its tendons. These tendons are practically drawn out of the forearm, and may be of con- siderable length. Billroth figures # a case where the middle finger was torn out, taking with it the two flexor and extensor tendons in their entire length. When one tendon only is torn away with the finger, it is usually that of the flexor profundus. Amputation at the wrist-joint by the cir- cular method.* — In the dorsal wound will be cut the following tendons : the extensores longus, indicis, communis, minimi digiti, and ulnaris, the radial nerve, and the dorsal branch of the ulnar nerve. Thetwo radial extensors will be cut short in the radial angle of the wound, as will also be the ex- tensores ossis and brevis. The radial artery will be * See "Manual of Operative Surgery," by Sir Frederick Treves, Bart., G.C.V.O., C.B., and Jonathan Hutchinson, F.R.C.S. 1910. 324 THE UPPER EXTREMITY [Chap. divided close to the radius. In the palmar wound will be found the ulnar artery, the superficialis volse, the ulnar and median nerves, the opponens, flexor brevis, and abductor pollicis in part, the flexor brevis, opponens, and abductor minimi digiti in part (the bulk of the opponens being left behind on the hand), and the tendons of the flexor sublimis and flexor carpi radialis. The ten- dons of the flexor profundus and flexor longus pollicis are usually cut short close to the bones. Amputation of the thumb at the carpo- metacarpal joint by flaps. In the palmar flap will be cut the abductor, the short and long flexor, the opponens, and the adductor pollicis. The extensores ossis and brevis will be cut short in the posterior angle of the flap. The extensor longus and a considerable portion of the abductor indicis will be found in the dorsal flap. The vessels divided will be the two dorsal arteries of the thumb and theprinceps pollicis. There is great danger, in this operation, of wounding the radialis indicis and the radial artery itself where it begins to dip into the palm. Nerve supply of the upper limb. — The symptoms which follow a lesion to the nerves of the upper limb depend on the point injured. If the fifth spinal nerve be crushed between its origin in the spinal cord and its exit from the intervertebral foramen, either from fracture or caries of the cervical vertebrae, the injury is fol- lowed by paralysis, partial or complete, of the rhomboids, spinati, deltoid, biceps, brachialis anticus, and supinator longus, but strangely enough the lesion is not accompanied by loss of sensation. Perhaps the fact that the posterior root of the fifth cervical nerve is very small may assist to explain this fact (W. Harris). Injury to the cord just above the origin of the eighth cervical vertebra will leave the skin of the ulnar half of the arm anaesthetic, while the muscles of the fingers, hand, and wrist, and some of those at the elbow and shoulder, will be paralysed. The XVJ NEEVE SUPPLY OF UPPER LIMB 325 fibres for the innervation of the various groups of arm muscles pass out in quite an orderly man- ner by the fifth cervical to the first dorsal nerve from corresponding segments of the cord. Those for the abductors of the shoulder pass out by the fifth; for the adductors by the sixth and seventh; for the flexors of the elbow by the fifth and sixth ; for the extensors by the seventh and eighth ; for the extensors of the wrist and fingers by the sixth and seventh; and those for the flexors by the eighth and first dorsal. It is important to re- member that a cervical spinal nerve makes its exit from the canal opposite the origin of the next spinal nerve. Further, the nerve to each muscle is made up of fibres derived from two or more spinal nerves. The following is Dr. Herringham's account of the usual spinal origin of the fibres in the nerves of the upper limb, and of the usual supply of the chief muscles. (The figures indicate the fifth, sixth, seventh, and eighth cervical nerves, and the first dorsal nerve.) Nerves. — Nerve of Bell, 5, 6, 7 ; suprascapular, 5 or 5, 6 ; external cutaneous, 5, 6, 7 ; internal cutaneous, 1 or 8, 1 ; nerve of Wrisberg, 1 ; circum- flex, 5, 6 ; median, 6, 7, 8, 1 ; ulnar, 8, 1 ; musculo- spiral, 6, 7, 8, or 5, 6, 7, 8. Muscles. — 3, 4, 5, lev. anguli scap. ; 5, rhom- boids; 5 or 5, 6, biceps, brachialis ant., supra- and infraspinatus, teres minor ; 5, 6, deltoid, sub- scapulars; 6, teres major, pronator teres, flexor carpi rad., supin. longus and brevis, superficial thenar muscles; 5, 6, 7, serratus magnus; 6 or 7, extensores carpi rad. ; 7, coraco-brachialis, latiss. dorsi 5> extensors at back of forearm, outer head of triceps; 7, ^ 8, inner head of triceps; 7, 8, 1, flexor sublimis, flexores profund., carpi uln., long, poll., pronator quad. ; 8, long head of tri- ceps, hypothenar muscles, interossei, deep thenar muscles. In the cutaneous nerve supply of the fingers, it must be remembered that on the palmar aspect 326 THE UPPER EXTREMITY [Chap. ! 7 ! 7 Fig. 67. — Cutaneous nerve supply of upper limb. | 10 V Anterior aspect : 1, Cervical plexus ; 2, circumflex ; 3, ext. cut. of muse spiral : 4, ext. cutaneous ; 5, median ; G, ulnar ; 7, int. cutaneous ; 8, n. of Wrisberg. Posterior aspect : 1, Cervical plexus : 2, circumflex ; 3, int. cut. of muse. spiral ; 4,intercosto-humeral ; 5,n. of Wrisberg ; 6, int. cutaneous ; 7 ext. cut. of muse, spiral : 8 ext. cutaneous ; 9 ulnar ; 10, radial. XVJ NERVE SUPPLY OF UPPEK LIMB \m Fig. 68. — Showing the sensory distribution of the spinal nerves in the upper limb. The dotted lines indicate approximately the area of each nerve. No attempt is made to show the extent to which the root areas overlap. (For the nerves supplying each area see Fig. 67.) 328 THE UPPER EXTREMITY [Chap. the thumb, the two outer fingers, and the radial side of the ring linger are supplied by the median, the remaining one and a half fingers by the ulnar (Fig. 67). On the dorsal aspect, the thumb is supplied by the radial; the index and middle fingers are supplied (as far as the base of the second phalanx) by the radial, and over the second and third phalanges by the median. The little finger and the ulnar side of the ring finger are supplied by the ulnar. The radial side of the ring finger, as far as the base of the second phalanx, is supplied by the radial, and the rest of this side of the digit by the median (Fig. 67). The cleft between the middle and ring fingers is occasionally supplied by the ulnar, or partly by the ulnar and partly by the radial. The roots and spinal segments to which these nerves belong may be ascertained from Fig. 68. The roots are distributed in order of origin, the fifth cervical beginning on the radial or outer side of the shoulder, and the second dorsal, or sometimes the third, ending on the ulnar or inner aspect of the upper arm. The hand is mainly supplied by the seventh. The neighbouring spinal nerves, as is also the case with ordinary terminal branches, overlap widely in their distribution. The area of anaesthesia is much less than the area of anatomi- cal distribution. The nerves along the ulnar side of the arm are derived from cord segments which also give off sympathetic (sensory) nerves to the heart; in angina pectoris the^ heart is really the cause of the pain, but the patient feels it on, and refers it to, the ulnar side of the arm. Paralysis of the lower trunk of the brachial plexus. — Mention has already been made of a partial paralysis of the arm in cases where a cervical rib is present (see p. 176). The paralysis, which usually begins to appear soon after adult life is reached, and oftener in women than in men, is due to the pressure of the lowest trunk of the brachial plexus on the rib ; hence the distribution of the ulnar nerve is the area most XV] PAEALYSIS OF THE MUSCULO-SPIKAL 329 affected. Dr. Wood Jones has shown that the subclavian groove of the first rib is caused by the lowest trunk, and that the . pressure of this nerve is sufficient to cause bending of the rib in some cases. It is not, therefore, surprising that cases are recorded of nerve disturbance in the distribution of the lowest trunk ^ in individuals in whom there is no cervical rib. The lowest trunk evidently contains the main^ supply of vaso-motor nerves to the limb, for, in the cases just mentioned, the skin is often red and swollen as a result of a vaso-motor paralysis. Paralysis of the musculo-spiral nerve.— When complete, the hand is flexed and hangs flaccid ("drop wrist"), and neither the wrist nor the fingers can be extended. # The latter are bent and cover the thumb, which is also flexed and adducted. When attempts are made^ to extend the fingers, the interossei and lumbricales alone act, producing extension of the two distal phalanges and flexion of the proximal. Supina- tion is lost, especially if the elbow be extended so as to exclude the action of the biceps muscle. Extension at the elbow is lost, but there is practi- cally no loss^ of sensation unless the nerve is cut above the origin of its cutaneous branches. Sec- tion of the radial nerve in the upper part of the forearm gives no loss of sensation (Head and Sherren). Paralysis of the median nerve. — Flexion of the middle phalanx is impossible in every finger, as is^ also a like movement of the distal joint of the index and middle fingers. Partial flexion of the distal phalanges of the two inner digits is possible^ the inner part of the flexor pro- fundus being supplied by the ulnar nerve. Flexion of the proximal phalanx with extension of the second and third can still be performed in all the fingers by the interossei. The thumb is extended and adducted, and can neither be flexed nor opposed. Bending of the wrist is only possible when the hand is forcibly adducted by L* 330 THE UPPEIt EXTREMITY [Chap. means of the flexor carpi ulnaris, which is not paralysed. Pronation is lost. Section of the median or ulnar nerves at the wrist does not give rise to the results which one would expect from their anatomical dis- tribution. Such lesions have been recently in- vestigated by Head and Sherren. After section of the ulnar nerve in the forearm — taking this nerve as an example to explain their observations on nerves generally — they found that a certain form of sensibility, which they name epicritic, is lost over the area of anatomical distribution (Fig. 69). A B C D Fig. 69. — Results of section of the ulnar nerve (A, B), and of the median nerve (C, D). (Head and Sherren.) Black : Area in which epicritic and protopathic sensibilities are lost. Stippled : Area in which only epicritic sensibility is lost. Over this area the patient is unable to distinguish light touch (tested by cotton-wool) and degrees of temperature between 22°-40° C. In a small area of the fifth digit (see Fig. 69) neither pricks nor very cold or very hot things can be felt; in this area, besides epicritic sensibility, there is also lost another form which they name protopathic. But every where^ over the area of the ulnar nerve deep pressure is felt; deep sensibility remains because the nerves which subserve it arise in the forearm and reach the fingers by the tendons. If the tendons are cut, deep sensibility also is lost. The effect of cutting any nerve depends on XV] EPIPHYSES OF UPPER LIMB 331 the nature of the fibres it contains ; a nerve may contain epicritic fibres for a small area and proto- pathic for a much wider, or vice versa. Paralysis of the ulnar nerve, — Ulnar flexion and adduction of the hand are limited. Com- plete flexion of the two inner fingers is impossible. The little finger can scarcely be moved at all. The action of the interossei and two inner lum- bricales is lost. The patient is unable to adduct the thumb. In testing for paralysis of muscles in the hand it is extremely important to observe closely the muscles which flex, extend, abduct, and adduct the thumb. The ulnar border of the metacarpal of the thumb can be approximated to the radial border of the corresponding bone of the index finger by only two muscles — the adductor pollicis and first dorsal interosseous. Theseare paralysed when the ulnar nerve is cut. Their action may be simulated by the flexor longus pollicis, brevi3 pollicis, or opponens pollicis, but in such cases it will be observed that it is not the ulnar border but the flexor surface of the thumb which is moved towards the metacarpal bone of the index finger. Epiphyses of the upper limb,— The epi- physes about the elbow join the shafts of their respective bones at 17 years (except the tip of the internal condyle, which joins at 18). The epi- physes at the shoulder and wrist extremities of the bones join at 20. The nutrient canals of the three bones run towards the elbow. The nutrient artery of the humerus comes from the brachial or inferior profunda, those of the radius and ulna from the anterior interosseous. The nerve supplying the humerus is the mus- culocutaneous. The radius and ulna are sup- plied by the anterior interosseous of the median. It may be taken as a general law that the nerve supply of a bone is the same as that of the muscles which are attached to it. PART IV.— THE ABDOMEN AND THE PELVIS CHAPTER XVI THE ABDOMEN THE ABDOMINAL PARIETES Surface anatomy. — The degree of prominence of the abdomen varies greatly. The protuber- ance of the belly in young children is mainly due to the # relatively large size of the liver, which occupies a considerable part of the cavity in early life. It also depends upon the small size of the pelvis, which ^ is not only unable to accommodate any abdominal structure (strictly so called), but can scarcely provide room for the pelvic organs themselves. Thus in infancy the bladder and a great part of the rectum are virtually abdominal viscera. After long- continued distension, as, for example, after preg- nancy, ascites, etc., the abdomen usually remains unduly prominent and pendulous. In cases of great emaciation it becomes much sunken, and its anterior wall appears to have collapsed. This change is most conspicuous about the upper part of the region. Here the anterior parietes immediately below the line of the costal cartilages, instead of being in the same plane with the anterior thoracic wall, may so sink in as to 332 Chap. XVI] THE ABDOMINAL PARIETES 333 be almost at right angles with that wall on the one hand, and with the lower part of the ab- dominal parietes on the other. In such cases the abdominal walls just below the thoracic line may appear to be almost vertical when the patient is in the recumbent posture. This change of sur- face is of importance in gastrostomy, since the subjects for that operation are usually much emaciated, and the incision has to be made close below the costal line. The position of the linea alba above the um- bilicus is indicated by a slight median groove, but no such indication exists below the navel. The linea semilunaris may be represented by a slightly curved line drawn from about the tip of the ninth costal cartilage to the pubic spine. In the adult it would be placed about 3 inches from the navel. Above the umbilicus the line is indicated on the surface by a shallow depression. The outline of the rectus can be well seen when the muscle is in action. It presents three " linese transversa, ;; one usually opposite the xiphoid cartilage, one opposite the umbilicus, and a third between the two. The two upper of these lines are obvious in well-developed subjects. The site of the umbilicus varies with the obesity of the individual and the laxity of the ab- domen. It is always below the centre of the line between the xiphoid cartilage and the pubes. In the adult it is some way above the centre of the body, as measured from head to foot, while in the foetus at birth it is below that point. It corre- sponds in front to the disc between the third and fourth lumbar vertebrae, and behind to the tip of the third lumbar spinous process. It is situated about j of an inch above a line drawn between the highest points of the two iliac crests. The anterior superior spine, the pubic spine, and Poupart's ligament are all conspicuous and important landmarks. The pubic spine is nearly in the same horizontal line as the upper edge of the great trochanter. It is very distinct in thin 334 THE ABDOMEN AND THE PELVIS [Chap. subjects. In the obese it is entirely lost beneath the pubic fat. In such individuals, however, it can be detected, when the subject is a male, by invaginating the scrotum so as to pass the finger beneath the subcutaneous fat. In the female the position of the process may be made out by ad- ducting the thigh and thus making prominent the tendon of origin of the adductor longus mus- cle. This muscle arises from the body of the pubes immediately below the spine, and by run- ning the finger along the muscle the bony promi- nence may be reached. If the finger be placed upon the pubic spine it may be said that a hernia descending to the inner side of the finger will be inguinal, while one presenting to the outer side will be femoral. In the erect position of the body the anterior superior spine is a little below the level of the promontory of the sacrum, while a point taken over the junction of sternum and ensiform process — the stemo-ensiform point — is opposite the upper part of the tenth dorsal ver- tebra. This point can be readily # recognized in even fat subjects by the depression below the sternal insertions of the seventh pair of costal cartilages, and, as will be seen presently, forms a valuable landmark. A point taken midway between the umbilicus and sterno-ensiform — the mid-epigastric point — lies opposite the disc be- tween the first and second lumbar vertebrae and is a j surface-marking of great clinical utility (Addison). In that part of the back which corresponds to the abdominal region the erector spinse masses are distinct, and in any but fat subjects their outer edges can be well defined. Between these masses is the spinal furrow, which ends below in an angle formed by the two great gluteal muscles. Immediately behind the middle of the crest of the ilium is Petit's triangle, or the gap between the external oblique and latissimus dorsi muscles. The fourth lumbar spine is about on a level with the highest part of the iliac crest. In counting XVI] THE ABDOMINAL PAKIETES 335 the ribs it is well to commence from above, since the last rib may not project beyond the outer edge of the erector spinse, and may consequently be overlooked. t The aorta bifurcates opposite the middle of the body of the fourth lumbar vertebra just to the left of the middle line about f of an inch below and to the left of the umbilicus. A line drawn on either side from the point of bifurcation to the middle of Poupart's ligament will correspond to the course of the common and external iliac arteries. The first two inches of this line would cover the common iliac, the remainder the ex- ternal. The coeliac axis comes off opposite the lower part of the twelfth dorsal vertebra, at a spot about lj inches above the mid-epigastric point, and that corresponds behind to the twelfth dorsal spine. The superior mesenteric and suprarenal arteries are just below the axis. The renal vessels arise about £ an inch below the superior mesen- teric, opposite the mid-epigastric point. The in- ferior mesenteric artery comes off from the aorta about 1 inch above the umbilicus. The deep epi- gastric artery follows a line drawn from the middle of Poupart's ligament to the umbilicus. Along the same line may sometimes be seen the superficial epigastric vein. The abdominal " rings " will be referred to under Hernia (p. 351). Anterior Abdominal Parietes The skin over the front of the abdomen is loosely attached in the region of the groin. It is more adher- ent to the deeper parts in the middle line than else- where, but not so adherent as to hinder the spread of inflammation from one side of the abdomen to the other. In cases of great obesity two transverse creases form across the belly, one crossing the umbilicus and the other passing just above the pubes. In the former of the two creases the navel 336 THE ABDOMEN AND THE PELVIS [Chap. is usually hidden from sight. In cases of anky- losed hip-joints transverse creases are often noted running across the middle of the belly. They are produced by the freer bending of the spine that is usually required in ankylosis, some of the simpler movements of the hip-joint being trans- ferred to the column when the articulation is rendered useless. After the skin has been stretched, from any gross distension of the abdomen, certain silvery streaks appear in the integument over its lower part. They are due to an atrophy of the skin produced by the stretching, and their position serves to indicate the parts of the parietes upon which distending forces within the abdomen act most vigorously. They are well seen after preg- nancy, ascites, ovarian tumours, etc. Beneath the skin is the superficial fascist, which over the lower half of the abdomen can be readily divided into two layers. The great bulk of the subcutaneous fat of this region is lodged in the more superficial of the two layers. In cases of great obesity the accumulation of fat is perhaps more marked beneath the skin of the abdomen than it is elsewhere. A layer of fat 6 inches in depth has been found in this region in cases of great corpulence. The superficial vessels and nerves lie for the most part between the two layers of the fascia, so that in obese subjects incisions may be made over the abdomen to the depth of an inch or so ^ without encountering blood-vessels of any magnitude. The deep layer of the superficial fascia con- tains elastic fibres, and corresponds to the tunica abdominalis or " abdominal belt ;? of animals. It is attached to the deeper parts along the middle line as far as the symphysis, and to the fascia lata just beyond Poupart's ligament. In the in- terval between the symphysis and the pubic spine it has no attachment, but passes down into the scrotum and becomes the dartos tissue. Extrava- sated urine that has reached the scrotum may XVIJ ANTERIOR ABDOMINAL TARIETES 337 mount up on to the abdomen through this in- terval, and will then be limited by the deeper layer of the fascia. It will not be able to pass ; down into the thigh on account of the attachments i of the fascia, nor, for a like reason, will it tend to pass over the middle line. In the same way emphysematous collections following injuries to the chest, when beneath the deeper layer of the fascia, receive a check at the groin, and lipomata also that grow beneath the membrane tend to be limited by the middle line and that of Poupart's ligament. The anterior abdominal parietes vary in thick- ness in different subjects. In cases of great emaciation the outlines of some of the viscera may be readily made out or even seen through the thinned wall. In some cases of chronic intestinal obstruction the outlines of the distended intestine are visible, and their movements can be watched ; in instances of obstruction of the pylorus the movements of the dilated and hypertrophied stomach can often be seen. The relative thickness of the abdominal wall in various subjects depends rather upon the amount of the subcutaneous fat than upon the thickness of the muscles. This muscular boundary affords an admirable protec- tion to the viscera within. By contracting the abdominal muscles the front of the belly can be made as hard as a board, and in acute peritonitis this contraction can sometimes be seen to produce a remarkable degree of rigidity. A blow upon the abdomen when the muscles are firmly contracted will probably do no injury to the viscera unless the violence be extreme. The rigid muscular wall acts with the efficacy of a dense indiarubber plate. It may be bruised or torn, but it will itself receive the main shock of the contusion. The probable effect on the contained viscera of a blow upon the abdomen will depend upon many factors; but, so far as the walls themselves are concerned, the effect greatly depends upon 338 THE ABDOMEN AND THE PELVIS [Chap. whether the blow was anticipated or not, and upon the extent of the padding of fat that is fur- nished to the parietes. If the blow be anticipated the muscles of the belly will be instinctively contracted, and the viscera at once provided with a firm but elastic shield. Thus the abdo- minal muscles have been found bruised and torn while the viscera were intact, and, on the other hand, in cases probably where the muscles were inert or taken unawares, a viscus has been found to be damaged without there being any con- spicuous lesion in the belly wall. If the blow be anticipated also the body will probably be abruptly bent and the viscera be — as it were — removed from danger. Along the linea alba the abdominal wall is thin, dense, and free from visible blood-vessels. Hence in many operations upon the abdominal cavity the incision is made in the middle line. Along the outer border of the rectus muscle (i.e. about and just beyond the linea semilunaris) the parietes are also thin and lacking in vessels, and consequently that situation is well suited for an incision. Except in some operations on the kidney, stomach, or gall-bladder, incisions are seldom so placed. In most cases it is a question of either opening the abdomen in the middle line or in one of the iliac regions. About 1 inch below the navel the two recti muscles are almost in contact, and here the linea alba can scarcely be said to exist, while above, the muscles remain apart, the linea alba being normally § of an inch wide. In pregnancy, obesity, and ascites the supra- umbilical part may become 2 or more inches wide, but the narrow infra-umbilical part is unaffected ; when this part of the linea alba widens the con- dition is known as divarication of the recti. When this is the case the contents of the abdomen bulge out between the recti when these two muscles are thrown into action, as when a patient at- tempts to assume the sitting from a supine posture unaided by the arms. Pellets of sub- XVI] THE UMBILICUS 339 j peritoneal fat may grow through interstices in the linea alba and give rise to what are called " fatty hernise." The fibrous ring of the umbilicus is derived from the linea alba. To this ring the adjacent structures — skin, fascia, and peritoneum — are all closely adherent. The adhesion is such, and the amount of tissue between the skin and peritoneum is so scanty, that in operating upon an umbilical hernia it is scarcely possible to avoid opening the sac. The umbilicus represents the point where the lateral abdominal walls finally close. At the sixth week the opening is funnel-shaped and con- tains the yolk sac and a fold of the bowel to which it is attached. This condition may persist and give rise to a congenital umbilical hernia. In the foetus three vessels enter at the navel, and i immediately separate on reaching the abdominal cavity, the vein passing directly upwards and the | arteries obliquely downwards. Running down from the umbilicus in the middle line is also the I remains of the urachus. In the foetus, the spot where the three vessels part company is about the centre of the navel, and it thus happens that in a congenital umbilical hernia the gut as it escapes separates the three vessels, which become to some extent spread over it. The congenital hernia, in- deed, works its way in among the structures of the cord and receives its main coverings from them. These hernise are fortunately rare, for in certain instances they extend some way into the cord, and in at least two reported cases the gut was cut across by the accoucheur in dividing the cord at birth.* As the abdomen increases in height the contraction of the two obliterated arteries and of the urachus drags upon the cica- trix and pulls it backwards and downwards. * The congenital hernia must be distinguished from the infantile umbilical hernia so commonly met with after separation of the cord. For an account of these congenital hernise, see paper by the Author in the Lancet, vol. i., 1881, p. 323. 340 THE ABDOMEN AND THE PELVIS [Chap. Thus, in the adult umbilical ring, as viewed from the inner side, the cords representing not only the obliterated arteries and the urachus, but also the vein, appear to start from the lower border of the cicatrix. In adult herniae, indeed, the gut escapes above both the obliterated arteries and the vein. The upper half of the cicatrix is thin when compared to the lower half, and is sup- ported also by less firm adhesions. In some cases there is # found at the navel a fistula that discharges urine. This is due to a patent urachus. The urinary bladder is formed by a dilatation of the stalk of the allantois. The part below this dilatation becomes the first part of the urethra, that above becomes the urachus. In one instance of patent urachus the abnormal open- ing was 1 inch in diameter. The patient, a man aged 40, had a stone, which was extracted by passing the finger into the bladder through the opening at the umbilicus. Sometimes a fistula discharging faeces is met with at the navel. This depends upon the per- sistence of the vitello-intestinal duct, a duct that at one time connects the intestine of the early foetus with the yolk sac, and which generally dis- appears without leaving any trace. The per- sistent duct, when it occurs, is known as Meckel's diverticulum, and springs from the ileum some two or more feet above the ileo-caecal orifice. This foetal relationship also explains the presence of a fibrous cord which is sometimes seen con- necting Meckel's diverticulum with the umbilicus. This fibrous cord may cause strangulation of the bowel (Fig. 79, p. 393). The position of the transverse intersections of the rectus muscle should be borne in mind. They adhere to the anterior layer of the rectus sheath, but not to the posterior. They are able, therefore, to some extent to limit suppurative collections and haemorrhages beneath^ the sheath on its anterior aspect. This muscle is often the seat of one form of " phantom tumour." These XVII THE KECTTJS 341 tumours are mostly met with in the hysterical and hypochondriac, and when associated with some vague abdominal symptoms are apt to mis- lead. They are due to a partial contraction of the muscle, usually to a part between two inter- sections, and are said to be more common in the upper part of the rectus. When the fibres of the muscle are contracted the " tumour " is obvious, but when they relax it disappears. The phantom tumour, however, is not always a matter of little moment. It may be associated with grave disease within the abdomen, and be due to reflex muscular contraction, the starting point of such reflex act being in the viscera. These localized contractions may provide a clue to the seat of visceral disease. Thus the stomach derives its chief sensory nerve supply from the eighth dorsal segment of the cord; the section of the rectus between the upper and middle inscriptions is also supplied from this segment through the eighth dorsal nerve ; hence contraction of this section may be asso- ciated with disease of the stomach. The rectus receives nerves from the lower six dorsal nerves; the section at the umbilicus is supplied by the tenth. I have, for example, seen a conspicuous phan- tom tumour in the upper part of the right rectus associated with cancer of the stomach, with ulcer of the duodenum, and with malignant disease of the peritoneum. Other vanishing tumours depend upon disten- sion of the intestines by flatus or by faecal matter. In great distension of the abdomen the fibres of the rectus may be much stretched, since they bear the brunt of the distending force. The direction of the^ fibres also renders them liable to be torn in opisthotonos, or extreme arch- ing of the back, or tetanus. Portions of the muscle have also been ruptured by muscular violence, as in vaulting. The lateral muscles of the front abdominal wall are separated from one another by layers 342 THE ABDOMEN AND THE PELVIS [Chap. of loose connective tissue. In the tissue between the internal oblique and transversalis are found the chief nerves and arteries. Everywhere the peritoneum is bound to the abdominal wall by subperitoneal connective tissue. In the pelvis this tissue is lax to allow the viscera of the pelvis — the bladder, rectum, and uterus — to expand; so, too, over the iliac fossae and on the anterior abdominal wall for two inches above Poupart's ligament and the symphysis pubis; but above this level and on the under surface of the diaphragm it binds the f>eritoneum down closely. The looseness of this ayer greatly favours the spread of abscess, to the progress of which it offers little resistance. Such an abscess may spread from the viscera, especially from those that have an imperfect peritoneal covering, as, for example, the kidney, the vertical parts of the colon, etc. The laxity of this tissue has been of service in certain surgical procedures. Thus the external and common iliac arteries can be reached by an in- cision made some way to the outer side of the vessels and without opening the peritoneum. That membrane having been exposed in the lateral wound, the artery is reached by working a way with the finger through the subperitoneal tissue, and by actually stripping the serous mem- brane from its attachments. Ligature of the iliac vessels at the # present day is usually effected through a direct incision which opens the peri- toneal cavity. The method just detailed belongs to pre-antiseptic days. The laxity of the sub- serous layer also favours that stretching of the peritoneum which occurs under certain circum- stances. Wounds of the abdomen may give trouble in their treatment, since, when inflicted, they may open up several layers of fascia and so lead to bagging of pus and to the spread of suppura- tion should an abscess follow the lesion. The constant respiratory movements of the belly walls XVI] VESSELS OF ABDOMINAL WALLS 343 do not favour that rest which is so essential to the healing of wounds. In penetrating wounds the contraction of the muscles may encourage the protrusion of the viscera, especially when the incision is transverse to the direction of the muscular fibres. In reducing small portions of protruded viscera it is quite possible to push them into one of the connective tissue spaces be- tween the muscles or into the subserous tissue in- stead of into the peritoneal cavity. In applying sutures to wounds involving the whole thickness of the parietes it is necessary that the threads should include the peritoneum, so that early healing of that membrane may be brought about. Without such precaution a gap may be left in the surface of the peritoneum which would favour the formation of a hernia in the site of the old wound. Blood-vessels.— The only arteries of any mag- nitude in the abdominal walls are the two epigastric arteries, some branches of the deep circumflex iliac, the last two intercostal vessels, the epigastric branch of the internal mammary, and the abdominal divisions of the lumbar arteries. The superficial vessels are of small size, although Verneuil reports a case of fatal haemorrhage from the superficial epigastric vessel. The superficial veins on the front of the abdomen are numerous, and are very distinct when varicose. A lateral vein, extending from the axilla to the groin, uniting the axillary and femoral veins, is often rendered in this way very prominent. The surface abdominal veins may take no part as alternative blood channels in cases of obstruction of the inferior vena cava. Clinical experience shows that these veins may be also enormously varicose in instances where the inferior cava is quite patent. In one case under my care there was extensive varicosity of the surface veins from the pectoral region to the groin that involved one side of the body only. 344 THE ABDOMEN AND THE PELYIS [Chap. It has been shown, moreover, that the valyes of these vessels are so arranged that the blood in the surface veins above the navel goes to the axilla, while that in the veins of the subumbilical region runs to the groin. In the neighbourhood of the umbilicus these veins are connected with the portal vein in the liver through anastomotic venous channels in the falciform ligament of the liver (Sappey). As regards the surface lymphatics of the front of the abdomen, it may be ( said in general terms that those above the umbilicus go to the axillary glands, and those below to the glands of the groin. Nerves. — - The abdominal wall is supplied by the lowest six dorsal or intercostal nerves, and by the first lumbar nerve. These nerves run obliquely to the long axis of the abdomen down- wards and inwards from the sides to the # middle line and hence are damaged more extensively in vertical than in oblique incisions. Their direc- tion is represented by a continuation of the lines of the ribs : they are placed parallel to one another and at fairly equal distances apart. It is important to note that they supply not only the abdominal integument, but also the muscles of the belly, viz. the rectus, the two oblique muscles, and the transversalis. The segments of the spinal cord which supply the skin # also innervate the underlying muscles, an association of great importance (Fig. 70). If a cold hand be suddenly placed upon the belly the # muscles at once contract and the abdomen is instinctively rendered rigid. The # safety of the viscera, at least so far as protection from contusions is con- cerned, depends upon the readiness with which the muscles can contract at the first indication of danger. As has been already stated, the viscera have a very efficient protection against the effects of blows when the belly muscles are in a state of rigid contraction. The sensitive skin acts the part of a sentinel, and the intimate asso- XVI] NERVES OF ABDOMINAL WALLS 345 ciation of the surface nerves with the muscular nerves allows the warnings of this sentinel to be readily given and immediately acted upon. The rigidity of the muscles in certain painful affec- tions of the skin over the abdomen is often very DlAPHRAQMATlC Cardiac Oesophageal esical emalTesticular Fig. 70. — Showing approximately the areas of skin supplied t by spinal nerves on the anterior surface of the trunk. The areas are marked on the left side by dotted lines, and the number of the spinal nerve by which each is supplied is indicated. The nerves are shown on the right side. The red stippled areas show the regions to which pain is commonly referred in connexion with visceral disease— according to the observations of Dr. James Mackenzie. The pain radiates towards the unenclosed part of each area. conspicuous. I might instance the^ case of a man with a burn over the belly. While the burn is protected by the dressings the abdominal muscles are lax and the parietes move with the respiratory act. The moment the dressings are removed, the surface becoming painful, its spinal 346 THE ABDOMEN AND THE PELVIS [Chap. centre becomes excited and the muscles at once contract and the belly becomes rigid. It will be noticed that six of the abdominal nerves supply intercostal muscles, and are thus intimately associated with the movements of re- spiration. The abdominal muscles are of course concerned "in the same movements. These asso- ciations are illustrated when cold water is sud- denly dashed upon the belly. The subject of such experiment at once experiences a violent respiratory movement in the form of a deep gasp. When the abdominal muscles are firmly fixed the lower ribs are also rigid, and respiration is limited to the higher ribs and to the thorax proper. There are other practical points about these nerves. In caries of the spine, and in certain injuries to the column, the spinal nerves may suffer injury as they issue from the vertebral canal. This injury may show itself by modified sensation in the parts supplied by such nerves. Thus in Pott's disease the patient often com- plains of a sense of tightness about the abdomen, as if a cord were tied around it. This sense^ of constriction depends upon an impaired sensation in the parts supplied by a certain pair of nerves ; or, if the sense of constriction be wider spread, by two or more pairs of nerves. In other cases a sense of pain may take the place of that of constriction. It would hardly be believed that spinal disease has been mistaken for " belly- ache.' ; But many such cases have been recorded. A child complains of pain over the pit of the stomach or about the umbilicus, and this feature may quite absorb for a while the surgeon's atten- tion. The abdomen is carefully poulticed, while the only mischief is in the vertebral column. Other symptoms, however, develop, and it be- comes evident that the pain is due m to pressure upon the nerves supplying the skin over the epigastric or umbilical regions, and that that pressure is a circumstance in the course of spinal XVI] NEEVES OF ABDOMINAL WALLS 347 bone disease. A case came under my notice in which a man complained of intense and abiding pain over the stomach. The pain was made worse by food, and as all means used failed to relieve it, the abdomen was opened by an ex- ploratory incision. Nothing abnormal was dis- covered. A little later it became evident that the pain was due to a malignant tumour situated in the bodies of the dorsal vertebrae. There had never, before the operation, been any suspicion of spinal disease. The site of the painful part depends, of course, upon the position of the spinal ailment, and thus the cutaneous symptoms may serve to localize the caries in the vertebrae. Thus the skin over the " pit of the stomach " is supplied by the sixth and seventh dorsal nerves, and the tenth nerve is nearly in a line with the umbilicus. The position of the areas supplied by each spinal nerve on the trunk is shown in Fig. 70. The umbilicus may be at the upper or lower border of the area of the tenth, accord- ing to the individual. A spinal root may be cut and yet scarcely a trace of anaesthesia may result owing to the overlapping of the nerve distributions. Not only may a lesion at the origin of a spinal nerve give rise to a pain referred by the patient to the abdomen, but, as may be readily understood from the .fact that the nerves of the abdominal wall also supply the lower half of the thorax, thoracic lesions may also give rise to symptoms which are referred to the abdomen. Pain or tender areas in the upper part of the abdomen may be actually due to a pleurisy in the lower part of the thorax. Although the course of the spinal nerves in the body wall is oblique — following the axes of the ribs — yet in their final distribution they supply zones of skin which approximately pass horizont- ally round the body. This is due to the fact that the posterior primary divisions and lateral cutaneous branches, before they reach their areas 348 THE ABDOMEN AND THE PELVIS [Chap. of skin, descend to the same level as the anterior cutaneous nerves — the terminal branches of the anterior divisions. Indeed, the lateral cutaneous nerves of the lower segments, as the lower limb is approached, actually descend further than the anterior cutaneous nerves (Fig. 70). The hori- zontal arrangement of the skin areas is demon- strated by the distribution of the cutaneous lesions in herpes zoster — a disease which is now ascribed to a lesion of the ganglia of the pos- terior roots. The nerves of the body wall have still more important associations. The cord segments with which they are connected are also in communica- tion with the viscera of the abdomen and thorax through the sympathetic system. Hence diseased conditions in the abdominal viscera give rise to disturbances in the corresponding cord segments, and the brain, being accustomed to localize pain only along the spinal nerves, makes a mistake and refers the pain along the spinal nerve of the seg- ment disturbed. Not only is pain referred, but the skin supplied from the disturbed spinal seg- ments becomes tender, and through a study of these areas of tenderness Head has been able to localize the visceral centres in the spinal cord, thus affording the surgeon a means for increased accuracy of diagnosis. The abdominal viscera are supplied from the sixth dorsal to the first lumbar spinal segments, the nerves t passing to their destinations through the rami communi- cantes, splanchnic nerves and sympathetic plexuses of the abdomen. No visceral nerves es- cape by the second, third, or fourth lumbar nerve roots, hence these are never the seats of visceral referred pains. The pelvic viscera are supplied from the fifth lumbar to the third or sometimes fourth sacral nerve through the nervi erigentes. It is important to remember, too, that there are three systems of nerves in the belly wall : (1) the nerves to the skin; (2) the nerves to the XVI] NERVES OF ABDOMINAL WALLS 349 muscles (motor and sensory) ; (3) the nerves to the parietal peritoneum. Any one or all of these three sets may be the seat of referred pain, the most common being the muscular nerves. The pain elicited by pressure on the muscles or by move- ments is usually, but erroneously, regarded as situated in the diseased viscus. The tonus and condition of the muscles of the abdominal pari- etes are influenced by the condition of the vis- cera through the > interconnexion of their nerve systems in the spinal cord. The following are the segments with which each viscus is connected (Head) : Stomach, 6, 7, 8, 9 D. ; intestine, 9, 10, 11, 12 D. ; rectum, 2, 3, 4 S. ; liver and gall bladder, 7, 8, 9, 10 D. ; kidney and ureter, 10, 11, 12 D., 1 L. ; prostate, 10, 11 D., 5 L., 1, 2, 3 S. ; epididymis, 11, 12 D., 1 L. ; testis and ovary, 10 D. ; appendages of uterus, 11, 12 D., 1 L. ; uterus, 10, 11, 12 D., 1 L., 3, 4 S. This nerve relationship is illustrated in dis- ease in many ways. Thus, in acute peritonitis and in laceration of certain of the viscera the abdominal muscles become rigidly contracted, so as to insure as complete res£ as possible to the injured parts. In acute peritonitis, again, the belly is very^ hard, and the respirations are purely thoracic ; and so entirely do the cuta- neous ^ portions of these nerves _ enter into the situation, that the patient is frequently unable to tolerate even the most trifling pressure upon his abdomen. Congenital deformities of the abdomen. — At the end of the second^ month of development, part of the intestine projects through the widely open umbilicus within the cord when it is only covered by the transparent covering membrane of that structure. In the third month the intestines retreat within the abdomen, the cavity within the cord becoming obliterated and the umbilicus closed. e The process of retraction of the intestine may fail or even an opposite process may occur — other contents being added to those normally 350 THE ABDOMEN AND THE PELVIS [Chap. found within the cord. Thus result the various forms of congenital exomphalos, which may vary in severity from a small hernia to a protrusion of the whole of the more movable viscera. One of the most remarkable deformities is that known as extroversion of the bladder (ectopia vesicae). Here, not only is a part of the belly wall apparently absent, but also a part of the genito-urinary Membrane of Bladder W^ VuC Fr-cnum Fig. 71. — Condition of parts in extroversion of the bladder apparatus. In complete cases there is a defect in the abdominal wall from the umbilicus to the urethra. There is a widely open or defective symphysis pubis, and the anterior wall of the bladder, the principal part of the penis, and the whole of the roof of the urethra are absent (Fig. 71). The interior of the bladder and urethra are laid open and form part of the anterior abdominal wall. The unprotected or vesical area XVI] INGUINAL HERNIA 351 offers a weak resistance to the descent of the viscera, and bulges outwards when the patient stands up. The scrotum, also, as might be ex- pected from a reference to the development of that part, is bifid. HERNIA 1. Inguinal hernia. — In this form of rup- ture the herniated bowel occupies the inguinal canal for the whole or part of its entire length. This canal runs obliquely from the internal to the external abdominal ring, and is about li inches in length. It represents the track followed by the testis^ in its descent. It is, in a sense, a passage right through the abdominal wall, and is occupied by the spermatic cord. It is not a free canal, however, in the same sense as one would speak of an open tube, but is rather a potential one, a tract of tissue so arranged as to permit of a body being thrust along it. It is a breach in the abdominal wall, not a doorway ; a breach that is forcibly opened up and widened in the acquired forms of hernia. When a hernia occupies the inguinal canal it is covered in front by the integuments, the external oblique aponeurosis, and the lower fibres of the inter- nal oblique and transversalis muscles. It rests behind upon the transversalis fascia, the con- joined tendon, and the triangular fascia ; over it arch the transverse and internal oblique muscles, while below it is the angle formed by the union of ^Poupart's ligament with the trans- versalis fascia. The herniated bowel is con- tained within a " sac/' which is always formed of peritoneum. In congenital hernia the sac exists already formed as an abnormally patent " processus vaginalis." In acquired hernise the sac consists of that part of the parietal peri- toneum which the gut pushes before it in its descent. The ^external abdominal ring, J an inch ex- ternal to and above the pubic spine, is readily 352 THE ABDOMEN AND THE PELVIS [Chap. felt by invaginating the scrotum with the point of the finger, and then passing the digit up in front of the cord. If the nail be kept against the cord the pulp of the finger can readily recognize the triangular slit-like opening. Under ordinary circumstances in adults it will just admit the tip of the little finger.* The internal ring is 4 > K Lumbar Vert. : ^U.Cofinor< Iliac Art xt. iliac Art. ectus Abdominis eEPE.PiCAS.TRic Act. /Iesselbacm's TciAncue COURSE of Vas e.xt.a&domiaal r.inc Symphysis Pubic Spime QlMBER/1AT5LlCAMErtT From rhe FemORAl. Qmc. Course o/ vas *id Cord --Pemis Scrotum Fig. 72. — Surface markings for the inguinal and femoral canals. A.S.S., Anterior superior spine of ilium. situated about J an inch above Poupart's liga- ment^ midway between the symphysis pubis and anterior superior iliac spine. This is the femoral point; it lies directly over the femoral * In cases of congenital or acquired absence of the cord the external ring may be almost obliterated. Paulet quotes from Malgaigne the case of an old man whose testicle had been removed in infancy, and in whom the external ring was so small as to be scarcely recognizable. XVI] INGUINAL HERNIA 353 artery as that vessel escapes from the abdomen beneath Poupart's ligament (Fig. 72). ^ There are two principal forms of inguinal hernia, which can be best understood by a view of the anterior abdominal parietes from within (Fig. 73). From such an aspect it will be seen # that the peritoneum is marked by three linear ridges that run, roughly speaking, from the umbilicus to the Urachus Oblit. Hypogast. Art. Deep Epigast. Art. •Ext. Fossa -Ext. Iliac Aht. -Mid. Fossa Femoral Fossa Int. Fossa Obturator Fossa Fig. 73. — The sites of hernia as seen on the inner (peri- toneal) aspect of the abdominal wall. {After Merkel.) pelvic brim. One of these ridges follows the middle line from the navel to the symphysis and represents the urachus ; a second, that may be indicated by a line drawn from the femoral point to the navel, represents the deep epigastric artery ; while between these two, and much nearer to the epigastric vessel thanto the middle line, is the line formed by the obliterated hypo- ftric arbery (Fig. 73). By means of these ridges M 354 THE ABDOMEN AND THE PELVIS [Chap. the peritoneum is made to present three fossse, an external to the outer side of the epigastric artery, an internal between the urachus and the hypo- gastric artery, and a middle between the track of the latter vessel and the epigastric trunk. The internal ring (so called) is just to the outer side of the epigastric _ artery, and the site of the summit of the inguinal canal is indicated by a depression in the peritoneum (Fig. 73). When a hernia follows the inguinal canal throughout its entire length, it is called oblique, indirect, or external; "oblique" or "indirect" from its taking the oblique direction of the canal, "external" from the position of its neck with reference to the epigastric vessel. The coverings of such a hernia would be the same as those oJ the cord, viz. the skin, the superficial, inter- columnar, cremasteric and infundibuliform layers of fascia, the subserous tissue, and the peri- toneum. When the hernia escapes to the inner side of the deep epigastric artery, through the space known as Hesselbach's triangle, it is callec a direct or internal hernia, for reasons that wiL be obvious. There may be two forms of direci hernia. In one form the gut ©scapes through the middle fossa above described, in the other through the inner fossa between the hypogastric artery and the outer edge of the rectus muscle. The middle fossa is nearly opposite to the sum- mit of the external ring. A hernia escaping through that fossa would enter the inguinal canal some little way below the point of entrance of an oblique hernia, and would have the same coverings as that hernia, with the exception of the infundi- buliform fascia. The first covering, indeed, that it would receive from the canal structures would be the cremasteric fascia. The inner fossa cor- responds, so far as the inguinal canal is con- cerned, with the external ring. A hernia escap- ing through this fossa would be resisted by the conjoined tendon and ^ the triangular fascia. These structures are either stretched over the XVI] INGUINAL HEKNIA 355 hernia so as to form one of its coverings, or the conjoined tendon is perforated by the hernia, or lastly the gut deviates a little in an outward direction so as to avoid the tendon and appear at its outer side (Velpeau). In any case the hernia is forced almost directly into the external abdo- minal ring. The coverings of such hernise are the skin and superficial fascia, the intercolumnar fascia, the triangular fascia and conjoined tendon (with the exceptions above mentioned), the trans- versalis fascia, subserous tissue, and peritoneum. Direct versus indirect inguinal hernia. — The indirect hernia, as just hinted, may be con- genital, the direct is never congenital. In the congenital oblique hernia the outline of the # in- guinal canal and the relations of the various parts concerned are but little disturbed, and the differences between this form of rupture and the direct variety are conspicuous. The acquired oblique hernia, however, does not present such a contrast to the direct form as might be expected. In the first-named rupture, from constant drag- ging upon the parts, the internal ring becomes more or less approximated to the external ring, and the length of the canal, and consequently the obliquity of the hernia, is considerably reduced. Thus the axes of the two forms of rupture do not present such differences as to make their nature at once obvious. The direct hernia, however, on re- duction, will pass directly back into the belly, while the indirect will, even in old cases, take a slight but appreciable^ direction outwards. After the reduction of the direct hernia, the edge of the rectus muscle may be readily felt to the inner side of the aperture, the protrusion being, indeed, at the semilunar line. The direct hernia is usually small and globular, while the oblique rupture may attain large size, and tends to assume a pyriform outline. Forms of oblique hernia depending upon con= genital defects in the " vaginal process." 7 y he — 356 THE ABDOMEN AND THE PELVIS [Chap. testis in the foetus descends from the region of the kidney into the scrotum by a way through the abdominal wall that is afterwards known as the inguinal canal (see p. 351). Its descent is preceded by the passage into the scrotum of a process of the peritoneum, the vaginal process. The testicle usually enters the internal ring about the seventh month of foetal Sperm. Vessels and Vas Int. Abdom. Ring Proc. Vaginalis Mesentery Testis Proc. Vaginalis GUBERNACULUM Fig. 74. — The relationship of the processus vaginalis, gubernaculum, and plica vascularis to the testicle of the human foetus. life, and by the eighth month is in the scrotum. The process of descent, which was investigated and made clear by John Hunter some 150 years ago, is often misunderstood. The gubernaculum (Fig. 74) is a solid, bullet-like plug of growing tissue which, by a pure process of growth, burrows its way through the abdominal wall into the scrotum, carrying with it a process of peritoneum — the processus vaginalis — with the testicle and XVI] INGUINAL HERNIA 357 epididymis enclosed within the process. The lower or growing end of the gubernaculum is composed of rapidly proliferating cells; its upper part, which is attached to the globus minor and mesentery of the testicle, is composed of non- striated muscular tissue. It can be understood that the growing end of the gubernaculum may be diverted from its course and carry the testicle towards the root of the penis, or outwards in the groin, or backwards into the perineum. It was Hunter's opinion, and the evidence now accumulated goes to support him, that the pro- cess of descent is regulated by the full develop- ment of the testicle — probably by an internal secretion. Hence, if the testicle is imperfect, the process of descent is arrested, the testicle being left in the abdomen or stranded in the inguinal canal. The vaginal process is often found open at birth; one may infer from the observations of Zuckerkandl and of Sachs that, even in children three or four months old, the communication re- mains open in 30 to 40 per cent, of cases. The part of the processus vaginalis which surrounds the testicle becomes the tunica vaginalis, while the elongated tubular part between it and the internal abdominal ring is known as the processus funicu- laris. The manner in which the processus vaginalis is cut off is as follows. It becomes obliterated in two places, at the internal ring and at a spot just above the epididymis, the obliteration usually beginning at the higher point first. Supposing obliteration to have taken place at these two points, the vaginal process between them will be represented by an isolated tube. This soon shrinks, closes, and dwindles to an insignificant fibrous cord ; It may, however, remain patent in part, and if fluid accumulates in this patent portion, an " encysted hydrocele of the cord " is produced. As regards the mode of closure, three contingencies may happen, each giving rise to a particular form of hernia : (1) the "process" 358 THE ABDOMEN AND THE PELYIS [Chap. may not close at all; (2) it may close at the upper point only ; and (B) it may close at the lower point only. 1. When the vaginal process is entirely open, gut can readily descend at once into the scrotum. Such a condition is called a congenital hernia. Here the intestine is found to occupy a large sac of the peritoneum, the open orifice of which is placed at the internal inguinal ring. The term " congenital ;; is misleading, as the hernia is very rarely present at birth, although it is com- mon in early life. 2. When the process is closed only at the in- ternal ring the unduly large tunica vaginalis is found to extend up to that orifice. If a hernia forms it may invaginate the processus vaginalis. This is known as an infantile or encysted^ hernia. In such a case the tunica vaginalis lies in front of the sac, and therefore three layers of peri- toneum would have to be cut through before the gut could be reached. The term " infantile " was given to this rupture because the first cases reported were met with in infants; the terra " encysted, " because the hernial sac was con- sidered to be enclosed by the sac of the tunica vaginalis. 3. The funicular process may remain oper from the internal abdominal ring to the top ( oi the testicle and there end, the normal tunica vaginalis being beyond. Hernia into this process is called a hernia into the funicular process. There is another possible congenital defect that may predispose to hernia, viz. an abnormally long mesentery. If, in the dead subject, the inguinal canal be opened up, and an attempt made to draw a piece of gut down from the abdomen into the scrotum, it will be found that this cannot be done, owing to the shortness of the mesentery. In any case of scrotal hernia, therefore, the mesentery must become lengthened, and it is a question whether or not an abnormally long mesentery may exist as a congenital defect, and so predispose the XVIJ INGUINAL HERNIA 859 patient to rupture. More information is required upon the subject. Another factor which must be considered in the production of hernia is the tension or pressure within the abdomen. When a labourer lifts a heavy weight from the ground, the musculature of the abdomen is thrown into vigorous action, compressing the viscera and raising the pressure within the abdomen to 100 mm. of mercury or more. The compressed viscera seek out the weakest points in the abdominal wall, which are represented by the internal abdominal and other rings. The escape of viscera at the abdominal ring is prevented by the conjoined pa-rts of the internal oblique and transversalis. Mr. George Chiene observed that when a patient was asked to strain, this muscle contracted vigorously, so that a finger inserted into the inguinal canal was gripped between the conjoined tendon and Poupart's ligament. Hernise are notoriously frequent in men who have to lift and carry heavy burdens. The inguinal canal in the female is much smaller and narrower, although a trifle longer, than it is in the male. It is occupied by the round ligament, and offers such slight induce- ment to the formation of a rupture that acquired inguinal hernia is as rare among females as it is common among men. In the female foetus a pro- cess of peritoneum descends for a little way along the round ligament. It corresponds to the pro- cessus vaginalis of males, and is known as the canal of Nuck. If this process remains patent, as it not unfrequently does, it may lead to a rup- ture that corresponds to the congenital hernia of males. Indeed, in quite early life the inguinal rupture is about the only form met with in female children, if exception be made of umbilical hernia. Not uncommonly the ovary is found as one of the contents of the hernial sac — for in the newly-born child the ovary lies above the level of the pelvic brim and relatively near the internal 360 THE ABDOMEN AND THE PELVIS [Chap. abdominal ring. In all such instances of early in- guinal hernia the gut has travelled down a patent canal of Nuck. It only remains to be said, that in endeavour- ing to reduce an inguinal hernia by taxis the thigh should be flexed and adducted, for in this position the abdominal parietes that bound the inguinal canal are the most relaxed. This posi- tion of the thigh affects the inguinal region mainly through the attachments of the fascia lata to Poupart's ligament. In herniotomy an incision is made along the middle of the tumour and in its long axis, being so arranged that its centre shall correspond to the external ring. The superficial external pudic \xtery is usually divided in the operation. It is impossible to distinguish the various layers of tissue that cover the hernia, the only one, as a rule, that is recognizable being the layer from the cremaster. In dividing the constriction it is usually recommended to cut upwards in all forms of inguinal hernia. The only vessel in risk of being damaged is the deep^ epigastric. In the oblique form of rupture an incision directly^ up- wards would quite avoid this artery ; but in a direct hernia, where there is reason to suppose that the vessel is in close connexion with the neck of the sac, it is well that the incision be directed a little inwards as well as upwards. _ It should be remembered that the incision required to re- lieve a constriction is, if properly applied, of the most insignificant character. 2. Femoral Hernia.— In this form of rupture the gut leaves the abdomen through the femoral ring and passes down into the thigh along the crural canal (Figs. 72 and 73). The name " crural canal " is given to the narrow interval between the femoral vein and the inner wall of the femoral sheath. Like the inguinal canal, it is a potential rather than an actual canal, and exists only when the sheath has been separated from the vein by dissection or by a hernial protrusion of some kind. XVI] FEMORAL HERNIA 361 The canal is funnel-shaped, about i an inch in length, and ends opposite the saphenous opening. A point taken on Poupart's ligament midway be- tween the pubic spine and femoral point lies directly over the femoral ring; the centre of the saphenous opening is situated j of an inch below this point (Fig. 72). Femoral hernise are always acquired, and possess a sac, made by themselvep out of the parietal peritoneum covering the crura! ring and its vicinity. The canal is larger in women than in men, and thus it happens that this species of rupture is much more common in the former sex. The tendency to this hernia in women appears also to be increased by the weak- ening effects of pregnancy upon the abdominal walls. As the gut descends it pushes in front of it its sac of peritoneum and the septum crurale (the name given to the subserous tissue that covers in the femoral ring) and enters the crural sheath. The adhesions of the sheath limit its downward progress when it has travelled about J an inch, and it therefore passes forwards through the saphenous opening, pushing before it the cribri- form fascia. It then receives a covering from the superficial fascia and the skin. Owing to the rigidity of the structures about the femoral ring, the neck of the sac must always be small. For similar reasons its dimensions while in the femoral canal must of necessity be insignificant, but when once it has escaped through the saphenous open- ing the loose subcutaneous fasciae of the groin afford it ample opportunity for increase. When the hernia has passed through the saphenous open- ing it tends to mount upwards over Poupart's ligament, in the direction of the anterior superior iliac^ spine. Even when it overlaps the ligament considerably it can hardly be mistaken for an inguinal hernia, since it must always lie to the outer side of the pubic spine. The upward ten- dency of a femoral hernia has been variously explained. It has been ascribed to a supposed curve in the crural canal, the concavity of which M* 362 THE ABDOMEN AND THE PELVIS [Chap. is forwards. Scarpa believed it to receive its direction from the frequent flexion of the thigh. Probably one of the most important factors in the matter is the unyielding character of the lower edge of the saphenous opening. If an elas- tic capsule be dilated within the femoral canal it will be found to turn upwards and inwards oyer Poupart's ligament; the direction of expan- sion is determined by the circumstances just men- tioned and by the yielding character of the an- terior wall of the femoral sheath. The hernial sac is superficial to Scarpa's fascia. Relations* — When a hernia occupies the crural canal there are in front of it the skin and super- ficial fasciae, the iliac part of the fascia lata, the cribriform fascia, and the anterior wall of the crural sheath. Behind are the posterior wall of the crural sheath and pubic portion of the fascia lata, the pectineus muscle, and the bone. The boundaries of the femoral ring are, in front, Pou- part's ligament and the deep crural arch ; behind, the bone covered by the fascia lata and the pec- tineus; on the inner side, the conjoined tendon, Gimbernat's ligament, and the inner part of the deep crural arch; on the outer side, the femoral vein in its sheath (Figs. 72, 73). The spermatic cord lies (in the^ male) just above the^ anterior border ^ of the ring, and the epigastric artery skirts its upper and outer part. The little pubic branch of this artery passes round the ring to ramify over Gimbernat's ligament. In two cases out of seven the obturator artery arises from the epigastric. In 10 per cent, of cases the abnormal obturator passes on the inner side of the femoral ring and is in danger of being wounded in opera- tions for strangulation ; in other cases the artery descends to the outer side of the ring or may cross it (R. Quain). In one instance where the vessel was placed internally to the femoral ring the pul- sations of the abnormal arterywere felt before the parts were divided. In addition to the vessels about the ring there is also a pubic vein, which, XVI] OBTURATOR HERNIA 363 ascending from the obturator vein in the thyroid foramen, enters the external iliac vein. Its rela- tion to the crural ring varies in the same way as the abnormal artery last named. The size of the femoral canal and the degree of tension of its orifices vary greatly with the position of the limb. If the thigh be extended, abducted, and rotated outwards, these parts are made very tense, while they are the most lax when the limb is flexed, adducted, and rotated inwards. It is consequently in the latter position that the thigh should be placed when taxis is being at- tempted. In herniotomy the incision is made along the inner side of the tumour, and is so arranged that its centre corresponds to about the upper part of the saphenous opening. The constriction is usually at the neck of the sac, and caused by Gimbernat's ligament. It is divided by an in- cision directed upwards and inwards. 3. Obturator hernia.— In this form the gut, pushing before it the peritoneum, the subperi- toneal fat, and the pelvic fascia, escapes through the obturator canal (Fig. 73). The direction of this canal is, from behind, downwards, forwards, and inwards. The inguinal is separated from the femoral canal by the inner part of Poupart's ligament; the femoral is separated from the^ ob- turator by the horizontal ramus of the pubis. Beyond the canal the hernia may pass between the obturator membrane and the obturator exter- nus muscle and remain deeply placed, or it may make its way through the muscle or emerge above it and be then covered by the pectineus and adduc- tor brevis. The obturator artery is, as a rule, at the outer and posterior part of the sac. It is very rarely in front of it. The obturator nerve is generally found to the outer side of the sac, less commonly it is in front of it. The proximity of the nerve renders it very liable to be pressed upon, and pain along the nerve is often a marked feature of the rupture. The hernia presents 364 THE ABDOMEN AND THE PELVIS [Chap. beneath the pectineus muscle, to the inner side of the capsule of the hip, behind and to the inner side of the femoral vessels, and to the outer side of the adductor longus tendon. Pain on moving the hip is generally a conspicuous symptom. The obturator externus may be made tense by rotation inwards of the slightly abducted thigh. This hernia is much more common in females; and it is worthy of note that the orifice of the obturator canal can be examined, to some extent, through the vagina. Professor Wood reports a remarkable case where a hernial protrusion of a part of the adductor longus through a rent in the fascia lata was mistaken for an obturator hernia. 4. Rare forms of hernia. — In perineal hernia the sac, covered by the recto-vesical fascia, escapes through the anterior fibres of the levator ani muscle, between the prostate and the rectum. In the ischiorectal hernia the protrusion takes place into the ischio-rectal fossa. In pudendal hernia the sac lies in the posterior inferior half of the labium pudendi, escaping between the ascending ramus of the ischium and the vagina ; it has been mistaken for a cyst. In sciatic hernia the gut escapes through the great sacro-sciatic notch in front of the internal iliac vessels, above or below the pyriformis, and appears under the gluteus maximus muscle. As regards umbilical hernia, nothing remains to be added to what has been already said (p. 339), save that the sac from its position nearly always contains omentum, and may contain stomach. In lumbar hernia the gut escapes in front of the quadratus lumborum muscle, and appears on the surface through the triangle of Petit (the gap between the latissimus dorsi and external oblique muscles), and there- fore just above the highest point of the iliac crest. The sac must either force before it or (in cases of injury) come through the fascia lumborum and internal oblique muscles, since these structures form the floor of the triangle. The hernia may escape through the " upper lumbar triangle " — XVI] RARE FORMS OF HERNIA 365 a gap near the last rib where the aponeurosis of the transversalis is covered only by the latissimus dorsi. Macready {Lancet, Nov. 8th, 1890) has col- lected twenty-five examples of this hernia. Dia= phragmatic herniae* may be congenital or acquired. The former variety is by far the more common, and is due to simple arrest in the development of the diaphragm and persistence of the original con- nexion between the thorax and abdomen ; the position of this connexion is marked by the fibrous interval between the muscular fibres arising from the last rib and those springing from the external arcuate ligament. The congenital form very rarely occurs on the right side, the development of the liver securing the closure of the pleuro-peritoneal opening on that side. In the acquired form, which is usually the result of a crushing accident, the diaphragm may be lacerated at any point, but in the majority of instances the lesion is situated in the left dome over the stomach. In an adult subject dissected by Dr. N. Paterson the abdominal contents of the left hypochondrium occupied the left pleural cavity ; there was a large aperture in the left dome ; the condition had not been recognized during life and apparently had given rise to no marked symptom. Of the organs, the stomach is the most frequently dislodged, then the transverse colon, omentum, small gut, spleen, liver, pancreas, and kidneys, in the order named. The hernia may escape through the foramen for the gullet, but never through that for the vena cava, nor through the hiatus aorticus. A partial hernia of the stomach through the oesophageal orifice is not uncommon. Mr. W. A. E. Waller has recorded the case of a young man, aged 19, who died with obscure symptoms of obstruc- tion. The stomach was found incarcerated in the oesophageal orifice, the greater part having passed into the left pleural cavity. The parts commonly selected are the connective-tissue in- * For a description of the various forms, see Keith, Brit. Med. Journ . Oct. 2D, 1910. ' 366 THE ABDOMEN AND THE PELVIS TChap. tervals between the sternal and costal origins of the diaphragm in front and its vertebral and costal origins behind. These hernise are more common in males. Femoral and inguinal diverticula. — Re- cently Mr. R. W. Murray has called attention to the frequency with which diverticula of peri- toneum are found over the openings of the femoral and inguinal canals (see Fig. 73, p. 353). In 200 post-mortem examinations he found 52 femoral and 13 inguinal diverticula and yet no hernia. In some cases the inguinal sacs may be formed from the processus vaginalis, but all the femoral forms and probably the majority of the inguinal are caused by yielding of the fibrous tissue of the parietes over the femoral and internal abdominal rings. In these regions the peritoneum is so loosely bound to the abdominal wall that it may be evaginated by even a low degree of intra- abdominal pressure. Posterior Abdominal Parietes The lateral and posterior walls of the abdo- men are lined inside with two fascia;, the transversalis and iliac. The transversalis fascia lines the whole of the transversalis muscle, and is < much thicker below than above. Above, it joins the fascia covering the diaphragm, while below it is attached to the iliac crest and to the whole of Poupart's ligament, save at that spot where it passes into the thigh to form the anterior layer of the crural sheath. The iliac fascia encloses the ilio-psoas muscle, p the part over the psoas being the thinner.' This part is attached on the inner side to the sacrum, and to the spine at the points corresponding to the psoas origin. Above, it is attached to the ligamentum arcuatum internum, and on the outer side to the anterior layer of the lumbar fascia along the outer edge of the psoas. Below, the fascia en- closes the iliacus, and is attached to the iliac crest, XVI] POSTERIOR ABDOMINAL PABIETES 367 to the pelvic brim, and to Poupart's ligament, save at that part where the membrane passes be- neath the ligament to form the posterior wall of the crural sheath. It follows the ilio-psoas muscle to its insertion, and ends by blending with the fascia lata. The arrangement of these fasciae greatly influ- ences the progress and direction of abscess. Thus an abscess placed beneath the transversalis fascia will point either just above the iliac crest or Pou- part's ligament, or run down along the spermatic cord and distend the inguinal canal. The iliac fascia encloses the ilio-psoas in a very distinct osseo-aponeurotic space ; Between the fascia and the muscle (especially its iliac division) there is a good deal of loose connective tissue, and thus every facility is offered for the progress of subfascial abscesses in this region. The osseo- aponeurotic space is practically closed on all sides within the abdomen, and is only open below where the fascia passes with its muscle into the thigh. This opening being at the most dependent part of the space, it follows that the psoas or iliac abscess very commonly points on the upper part of the thigh, just to the outer side of the femoral vessels. An abscess in the iliac fossa, although most likely to reach the thigh, might mount up to the superior attachments of the fascia, and point at the iliac crest or at the outer part of Poupart's ligament. Or it may disregard the inner attachments of the fascia and gravitate into the pelvis. If the patient should occupy for long the recumbent pos- ture, there is no reason why it should not extend upwards along the psoas muscle. The term iliac abscess, however, is often ap- plied to collections that are not within the space formed by the iliac fascia, but that are situated rather in the subperitoneal connective tissue. This tissue is very extensive and lax in the iliac fossa in order^ to allow the expansion of the peritoneum which necessarily attends the filling and emptying of the caecum, colon, bladder, 368 THE ABDOMEN AND THE PELVIS [Chap. uterus, and rectum. Large collections of puru- lent matter may form in it or may spread into it from the pelvis. Some distance above Poupart's ligament (lj to 2 inches) the subserous tissue be- comes dense and the peritoneum closely bound down. Hence such abscesses remain in the iliac fossa, bulging out the abdominal wall just above Poupart's ligament, and occupying the angle formed by the union of the iliac and transversalis fasciae. In some cases they are disposed to extend into the pelvis. The abscess, when in the subserous tissue, is brought in close contact with certain of the vis- cera, especially with the caecum and sigmoid flexure, and into these portions of the colon it may open. Thus, I have seen a case of iliac abscess due to pelvic necrosis that opened into the sigmoid flexure, and at the same time discharged through sinuses about the groin. In this case some pus passed by the anus, while on the other hand some faecal matter escaped by the groin. Retroperitoneal abscesses^ in the pelvis (pelvic cellulitis) may mount up into the iliac fossae, may appear as " iliac abscesses/' and may ultimately discharge themselves by many openings in the lower parts of the anterior abdominal wall. It may be well to note that the common and external iliac vessels, the lymphatics, and the ureters are outside the iliac fascia, and rest upon its abdominal surface, while the anterior crural nerves and abdominal parts of the lumbar nerves are within the osseo-aponeurotic space. Thus the intrafascial abscess may, with little difficulty, reach the thigh by following the iliac vessels ; while the subfascial collection would pursue the anterior crural nerve. A psoas abscess, or abscess within the fascial sheath of the psoas muscle, is usually due to spinal caries, although it may appear independently of that disease. If the lumbar spine be involved the matter can pass directly into the substance of the muscle, which it will more or less entirely destroy. XVI] PSOAS ABSCESS 369 If the mischief be in the dorsal spine, the matter gravitates along the front of the column until it reaches the diaphragm, which it pierces by an inflammatory process. It is now brought into re- lation with the heads of the psoas, and has to pass through a narrow strait. The pus, following the muscle, at last reaches the thigh, and usually points, just below the groin, to the outer side of the femoral vessels. The substance of the psoas may be completely replaced by an abscess cavity. The abscess, however, often shows much varia- tion. It may avoid the psoas, or leave it when once it has entered it, and make its way into the lumbar region to find an exit in the loin. Or it may extend into the iliac fossa and open above the groin, or mount up over the iliac crest and discharge in the gluteal region. It may pass along the inguinal canal and be mistaken for a hernia. It may sink into the pelvis, and may open into the bladder, or discharge itself through the great sciatic foramen, or through a sinus in the perineum. Some of the latter cases have led to much confusion in diagnosis, since there would appear to be little connexion between caries of the spine and a perineal abscess. Lumbar region. — The muscles that form the lateral and posterior walls of the abdomen, and that fill in the interval between the iliac crest and the lowest rib, are the external oblique and latis- simus dorsi, the internal oblique, the transver- salis muscle with its fascia lumborum, the erector spinse and quadratus lumborum. The distance from the iliac crest to the tip of the nearest rib (usually the eleventh) varies from 3 to 7 cm., the average being 4*8 cm., a little less than 2 inches (Addison). The external oblique and latissimus dorsi mus- cles are separated by a small triangular interval below (the triangle of Petit), but above they over- lap. The interval is best marked in women. The outer border of the erector spinse affords a useful landmark in the lumbar region. At the crest of 370 THE ABDOMEN AND THE PELVIS the ilium the outer border of the quadratus lum borum extends an inch beyond the erector spinse, but at the twelfth rib it lies an inch internally to that muscle (Fig. 89, p. 429). The triangle of Petit is li to 2 inches beyond the erector spinse, or just behind the mid-point of the iliac crest. Between the last rib and the iliac crest is stretched the dense fascia lumborunij the posterior aponeurosis of the transversalis muscle. It is pierced near the rib by the last intercostal artery and nerve, and near the ilium by the ilio-hypo- gastric nerve and its accompanying artery. It is along these structures that an abscess may possi- bly find its way through the fascia in certain cases. The fascia divides behind into three layers, to enclose in definite spaces the quadratus and erector spinae muscles, the middle layer passing between these two muscles to the tips of the trans- verse processes. Within these spaces or compart ments suppuration may be for some time limited. A lumbar abscess commencing in some adjacent part, as in the spine or in the loose tissue around the kidneys, usually spreads backwards by pierc- ing the fascia lumborum or the quadratus muscle. The author's operation for caries of the lumbar vertebrae. — The lumbar vertebrae, and, possibly, the last dorsal, may be reached by an in- cision through the loin. A vertical cut is made along the outer edge of the erector spinse muscle. The fibres of that muscle having been drawn aside, the middle layer of the fascia lumborum is incised, and the quadratus lumborum is ex- posed. This muscle is divided vertically, and then the front of the vertebrae may be reached by in- troducing the finger under the psoas muscle. Through this incision the author has removed the whole of the body of the first lumbar vertebra that had been separated as a sequestrum (Med.-Chir. Trans., 1884). The lumbar arteries are avoided by keeping close to the transverse processes of the vertebrae. Through this incision a psoas abscess may be most conveniently opened. CHAPTER XVII THE ABDOMINAL VISCERA The peritoneum.— Certain of the viscera, as, for example, the stomach, spleen, and small in- testine, are so closely invested with peritoneum that they could not be wounded without that mem- brane being wounded also. Inflammatory affec- tions of such viscera are also very apt to involve the peritoneum. Other organs, such as the kid- ney, descending colon, pancreas, etc., are so im- perfectly covered with the serous membrane that a wound of those organs need not involve it, nor need it be implicated in even extensive inflamma- tory changes. Large abscesses may, for instance, form about the kidney and discharge themselves through the skin without any peritonitis being induced. Spontaneous perforation of the small intestine must involve the peritoneum, while, on the other hand, the duodenum and ascending colon may become perforated, and the matter escape into the subserous tissue without the serous membrane being in any way involved. It is note- worthy in connexion with bacterial infection that it is singularly easy to set up inflammation of the peritoneum if the membrane be approached from its inner surface, but comparatively difficult if it be approached from without. Thus a small puncture of the membrane may, on the one hand, lead to fatal peritonitis, while, on the other, it may be extensively torn from its attachments (as in ligaturing the common iliac artery from 371 372 THE ABDOMEN AND THE PELVIS [Chap. the side) without any peritonitis following. Or, again, a little pus escaping on the inner surface of the membrane may lead to inflammation, while the outer surface may be bathed with pus for a long while (as in large perirenal abscesses) with- out any peritonitis being produced. Fluid is rapidly absorbed from the peritoneal cavity; carmine particles are found within the thoracic duct seven minutes from their injection within the cavity; absorption takes place most rapidly in the subdiaphragmatic area (Dunbar and Eemy). Inflammation of the peritoneum may lead to the formation of a great variety of bands and ad- hesions, beneath which pieces of intestine may be caught and strangulated. The peritoneum will allow of very consider- able stretching if only that stretching be effected gradually. This is frequently seen in cases of gradual distension of the bowel, in the formation of the sac in hernia, and in the growth of retro- peritoneal tumours. Abrupt stretching of the membrane leads to certain rupture of it. The parietal peritoneum may be ruptured by violence without damage to any of the viscera. The great omentum is, from its position, very apt fo be wounded. In small wounds of the front of the belly it very often protrudes and acts as an excellent t plug to prevent the escape of other and more important structures. It is often found in hernia, especially in umbilical hernia, where it is almost constant. Its limits vary, and it has an inclination to the left side. This depends upon the fact that the omentum is developed from the mesogaster, and accounts for the fact that hernise containing omentum are much more common on the left side. > The omen- tum, like the other parts of the peritoneum, is apt to inflame, and to contract adhesions to the neighbouring parts. These adhesions are often of the greatest service in limiting inflammatory and hemorrhagic extravasations, by matting the bowels together and forming spaces between them. XVII] THE GREAT OMENTUM 373 In perforation of the bowel from disease, an opportune adhesion of the omentum over the aperture may prevent escape of the intestinal contents. Large masses of tissue may be nourished through an adherent omentum. Thus when the proper blood supply of an ovarian tumour has been cut off by twisting of its pedicle, the growth may be nourished through the omentum, if that structure is adherent to it. Rutherford Morri- son proposes to relieve congestion of the portal circulation by setting up an anastomosis between the omental vessels and the systemic circulation. When an adhesion between the omentum and parietal peritoneum is produced artificially, large anastomotic vessels open up and communicate with the vascular network beneath the parietal peritoneum, thus possibly relieving tension in cases of obstructed portal circulation. In cases of obesity fat collects conspicuously in the great omentum. In hernise the omentum generally con- tracts adhesions to the sac, and becomes irreduc- ible, or it may form a kind of second sac about the gut itself (" omental sac ")• The end of the omen- tum, by becoming adherent to distant parts, as to the pelvic viscera, may form itself into a firmly attached band, beneath which the bowel may be fatally strangled. In like manner the intestine has been strangulated through slits and holes that have developed in the omentum, usually as a re- sult of inflammatory adhesions. The functional meaning of the great omentum is by no means definitely established, but it undoubtedly increases the absorptive area of the peritoneum, and evi- dence is not lacking to show that it takes an active part in repelling bacterial invasions of the peri- toneal cavity. Thus, Dr. B. H. Buxton found that the mononuclear white corpuscles of the omentum of rabbits were soon laden with typhoid bacilli in cases where artificial cultures had been introduced within the peritoneal cavity. The mesentery. — The parietal attachment of 374 THE ABDOMEN AND THE PELVIS [Chap. the mesentery is liable to some variation. The point at which this attachment commences above is practically constant. It corresponds with the ending of the duodenum, is about on a level with the lower border of the pancreas, and is just to the left of the second lumbar vertebra. (See p. 379.) From this point the insertion of the mesentery follows an oblique line that runs downwards and to the right, crossing the great vessels, and then ending in a somewhat uncertain manner on the right iliac fossa (Fig. 75, p. 376). The parietal attachment of the mesentery measures, as a rule, about 6 inches. From its oblique attachment it follows that, when haemorrhage takes place in the abdomen on the right side of the mesentery, the blood first is conducted into the right iliac fossa; when on the left side, into the pelvis. This may explain the circumstance that collections of blood are more common in the right than in the left iliac fossa. The length of the mesentery from the spine to the bowel varies in different parts of the canal ; its average length is 8 inches. The longest part is that which goes to the coils of intestine that lie between a point 6 feet from the duodenum, and a point 11 feet from the same part of the gut (Author).* Such coils will, therefore, include 5 feet of the intestine, and the mesentery here may reach the length of 10 inches. These coils are apt to hang in the pelvis, and may be easily herniated. The length of the mesentery plays an important part in hernia. If the fresh body of an adult be opened, and the condition of the vis- cera and peritoneum be normal, it will be found that it is impossible to drag a loop of small in- testine through the femoral canal (artificially^ en- larged) on to the thigh, or down the inguinal canal into the scrotum. In fact, no coil can, in any part, be drawn out of the abdomen below a horizontal line on a level with the spine of the * See " The Anatomy of the Intestinal Canal and Peritoneum in Man," by the Author. London, 1885. XVII] THE MESENTERY 375 pubes. It is evident, therefore, that in femoral or scrotal hernia the mesentery must be elongated or its attachments lowered. The mesentery is relatively longest in infancy and childhood, and a freer escape of the intestines from the abdomen is allowed in subjects under puberty. The disposition of the membrane per- mits also a freer downward excursion of the bowels on the right side, and this has been offered as an explanation of the undue frequency of right- sided inguinal hernise in childhood (Lockwood). Mr. Lockwood states that in acquired hernia the mesentery is found to have had its attachments lowered rather than to have been increased in length. Certain holes are sometimes found in the mesentery, through which intestine has been strangulated. Some of these holes, especially those that are slit : like, are due to injury, others are due to congenital defect of the mesentery. Cases of imperfect attachments of the mesen- tery have been frequently recorded of late years. The primary attachment is at the origin of the superior mesenteric artery, from which a process of fixation extends during foetal life towards the right iliac fossa. If this process is completely arrested then the whole intestine may become rotated round the superior mesenteric artery, causing obstruction of the bowel, or, if the lower part of the mesentery is unattached, the loop formed by the lower part of the ileum and commencement of the great bowel may undergo a rotation and cause obstruction. Peritoneal spaces and communications. — Owing to the arrangement of the peritoneum the cavity of the abdomen is divided into a number of potential spaces which are connected together by certain definite communications or routes. Alimentary contents, pus, or blood escaping within the peritoneal cavity tend to^ collect in certain of these spaces and overflow into neigh- bouring spaces in well-defined directions. Some 376 THE ABDOMEN AND THE PELVIS [Chap. writers see in this arrangement of the peritoneum a resemblance to the watersheds of a country, and hence the potential spaces and routes are some- 5ple/iic Flexure Duode/ioJej. Flexure G Paracolic Croove Fig. 75. — Diagram showing the] average position of the abdominal viscera with their surface markings. (After Addison.) A, Sterno-ensiform point ; A' A', sterno-ensiform line : B, mid-epigastric point ; B'B', mid-epigastric or transpyloric line ; C, umbilical point ; C'C', umbilical line ; D, mid-hypogastric point ; D'D', mid- hypogastric line ; E,E, outer border of the right and left rectus abdominis ; F, Monro's point — on the right spino-umbilical line at the outer border of the rectus abdominis. times spoken of as the " watersheds of the peri- toneum. " The chief of these spaces are : (1) The lesser sac. This communicates with (2) the sub- hepatic space by the foramen of Winslow ; the space XVII] PEEITONEAL SPACES 377 is bounded above by the under surface of the iiver and below by the duodenum, hepatic flexure of colon, transverse mesocolon, right kidney, and right costo-phrenic ligament (Fig. 75). (3) The right subphrenic space between the diaphragm and liver; it is bounded towards the middle line by the falciform and coronary ligaments; below it opens into the subhepatic space. (4) The left subphrenic space, between the diaphragm above and left lobe of liver and stomach^ below ; it is separated from the corresponding right space by the falciform ligament ; below it communicates with (5) the perisplenic space; this space is bounded below by the splenic flexure and its mesocolon, the left costo-phrenic ligament and left kidney. These five spaces lie in the supra-omental region of the abdomen — above the transverse mesocolon ; below the transverse mesocolon there are two spaces, normally occupied by small intestine ; they are (6) the right infra-omental, bounded above by the transverse mesocolon, below and to the left by the duodeno-jejunal junction and root of the mesen- tery ; (7) the left infra-omental, bounded above by the transverse mesocolon; it is separated from the right space by the duodeno-jejunal junction and mesentery of the small bowel. The remaining space — the eighth — lies in the pelvis, the recto- uterine in the female, the recto-vesical in the male. Communications between the supra- and infra- omental spaces exist only at the two extremities of the transverse mesocolon. Overflow from the subhepatic spaces tends to pass down the groove external to the ascending colon (right external paracolic groove) ; by that groove it reaches the iliac fossa ; from the iliac fossa, the pelvic space ; from the pelvis it may mount to the left infra- omental pouch, and from there the fluid matter may make its way to the left external paracolic groove and thence to the perisplenic space. In this description the writings of Barnard, Wallace, Box, Jenkins, and Maynard Smith have been followed. 378 THE ABDOMEN AND THE PELVIS [Chap. Surface markings of the abdominal vis- cera.— In F ig. 75 > is shown the^ position of the abdominal viscera in an average individual, while Fig. 76. — Diagram showing the position of the viscera in the condition of visceroptosis. A,A, Sterno-ensif orm line : it crosses above the fifth costal cartilage ; B,B, mid-epigastric line ; C,C, umbilical line ; D,D, mid-hypo- gastric line ; a, pericardium ; b, stomach (greatly elongated and dilated) ; c, liver ; c', Biedel's lobe ; d, duodenum ; e, caecum ; /, transverse colon ; g, rectum ; h, elongated gastro-hepatic omentum. in Fig. 76 is represented the position assumed by these viscera in a well-marked case of visceroptosis (Glenard's disease). Study of such cases, especially XVII] ABDOMINAL VISCERA 379 with the aid of X-rays, shows the need of an accurate and simple method of indicating the normal position of the abdominal contents. The upper limit of the viscera is best indicated by the sterno-ensiform point and line. The position of the sterno-ensiform point is indicated by a dis- tinct depression under the insertion of the seventh pair of costal cartilages; the sterno-ensiform line is drawn transversely on the body through this point and should cross _ the fifth pair of costal cartilages if the thorax is of normal shape. The right dome of the diaphragm, in the standing posture, reaches this line ; the left dome is i an inch below it; in the supine position the domes rise upwards \ an inch. The central tendon is \ an inch below the sterno-ensiform point. In visceroptosis the domes of the dia- phragm and viscera within them sink downwards until they lie 1 inch or more below their normal position (see Fig. 76). The mid-epigastric point is taken on the linea alba half-way between the umbilical and sterno-ensiform points; the mid- epigastric line (transpyloric plane of Addison) crosses the body at this point; it marks the level of the pylorus and pancreas, with the beginning and termination of the duodenum (Fig. 75). In visceroptosis the parts sink until they reach the umbilical line (Fig. 76). The umbilical line, drawn through the umbilicus, usually crosses somewhat below the highest point on the iliac crests; the transverse colon and duodenum cross the abdomen above the line, the bifurcation of the aorta is below it. In visceroptosis the transverse colon and duodenum descend well below the umbilical line (Fig. 76). The mid-hypo gastric point is taken on the linea alba half-way between the umbilicus and symphysis pubis ; it lies about 1 inch below the promontory of the sacrum. The mid-hypo- gastric line crosses the iliac colon in the left groin and the fundus of the caecum in the right. The outer border of the rectus abdominis (linea semi- lunaris) also serves as a useful guide ; at the point 380 THE ABDOMEN AND THE PELVIS [Chap. where it crosses the costal margin on the right side {right costo-rectal point) is situated the gall- bladder; on the left side the greater curvature of the stomach emerges from the hypogastrium at this point (Fig. 75). A line drawn from the umbilicus to the right anterior superior iliac spine (spino -umbilical line) provides a useful guide to the ileo-csecal region. Monro's point is situated on this line at the outer border of the rectus abdominis; the ileo-csecal orifice lies to the right of Monro's point immediately below the spino- umbilical line. The viscera are maintained in position by the action of several structures, but by far the chief are the muscles of the abdominal wall — the external and internal oblique, transversalis, rec- tus abdominis ; diaphragm, and levator ani. By their contraction or tonus they maintain the vis- cera firmly pressed together ; in the upright pos- ture the weight of the upper viscera rests on the lower viscera. That the muscles are the chief agents in maintaining the viscera in position can be shown in many ways. In rising from the supine to the upright posture the upper viscera and diaphragm are seen in the living body (by aid of X-rays) to descend about J an inch or more. When the muscles and belly walls are cut away, and the dead body raised to the upright position, all the viscera drop downwards to the extent of 2 inches or more. The peritoneal ligaments, reflections, omenta, and mesenteries merely limit the degree of movement ; the viscera are freely movable to allow the extensive respiratory action of the dia- phragm. Besides the peritoneal, there are other visceral supports formed by vessels and their sheaths of connective tissue, such as the attach- ment of the liver to the diaphragm by the in- ferior vena cava, the kidneys and small intestine to the posterior abdominal wall by their vessels. It is only when the muscles of the belly wall are thrown out of action that any strain or weight falls on the peritoneal and vascular supports. XVII] EELATIONS OF THE STOMACH 381 The stomach.— Its relationships are : — Above. Liver, small omentum, diaphragm. Behind. In front. Transverse mesocolon, (From left to right) dia- ^tOlll*l*»h lesser sac, pancreas, phragm, abdominal wall, »■»«■■■«»*>■■• crura, solar plexus, great liver. I vessels, spleen, left kid- ney, and suprarenal. Below. Great omentum, small intestines, transverse colon, gastro-splenic omentum. The oesophagus perforates the diaphragm slightly to the left of the middle line and ends at the cardiac orifice of the stomach, 3 to 4 inches deep to the terminal inch of the seventh left costal cartilage. The pyloric orifice, permanently closed by its sphincter except when the contents of the stomach are passing to the duodenum, is situated on the mid-epigastric plane and about 1 inch to the right of the linea alba in the dead body, but in the living, especially in the upright posture, its position is lower, being slightly to the right of the linea alba and about 2 inches above the umbilicus (see Fig. 75). Being situated under the quadrate lobe of the liver and bound to the trans- verse fissure by the gastro-hepatic omentum, en- largement or displacement of the liver necessarily causes a displacement of the pylorus; in cases of visceroptosis it may drop to the umbilical line (Fig. 76). Normally the lesser curvature^ is over- lapped by the liver, and the gastro-hepatic omen- tum is hid (Fig. 75), but when the stomach be- comes dilated, elongated, or falls down, the lesser curvature and gastro-hepatic omentum are ex- posed (Fier. 76). A curved line drawn from the position ofthe cardiac orifice (on the seventh left costal cartilage, 1 inch from the sternum) to the position of the pylorus (mid-way between the epi- gastric point and right costal margin) indicates the normal position of the lesser curvature. While the lesser curvature is comparatively fixed, owing to the attachment of the gastro-hepatic omentum, 382 THE ABDOMEN AND THE PELVIS [Chap. the greater curvature is freely movable; its posi- tion alters as the stomach is full or empty, con- tracted or relaxed. The variable position of the great curvature as seen in the living is repre- sented in Fig. 77 from observations made by Dr. A. F. Hertz. When the patient is standing, the great curvature descends to the umbilicus or below it; when lying down, the great curva- ture is an inch or more above the umbilicus. Simple dilatation of the stomach leads to a low position of the greater curvature without altering Fig. 77. — Radiographic outline of the stomach of a patient who has taken a bismuth-laden diet. (After Dr. A. F. Hertz.') A, Standing position ; B, horizontal position. the position of the lesser curvature; in ptosis of the stomach both curvatures descend, but the greater descends more owing to dilatation being always present (Fig. 76). In ptosis^ the curva- tures become more vertical in position (Fig. 76). The shape of the stomach depends on many conditions : on its state of physiological activity, on the pressure of surrounding organs, and on its degree of fullness. In life, its cardiac and pyloric parts react differently during^ digestion ; the cardiac part, which is vertical in position XVII] THE STOMACH 383 and constitutes about two-thirds of the organ, undergoes merely a tonic, not a peristaltic, con- traction. The pyloric part, tubular in shape and horizontal in position, is the seat of constant peri- staltic waves during digestion. These waves sweep towards the duodenum along the pyloric division. The point at which they begin is often found contracted after death, and this observation has given rise to the opinion that the cardiac and pyloric divisions are separated by a mid-gastric sphincter. When food is swallowed, it passes at once into the pyloric division, and, as more food is taken, both divisions of the stomach fill (Dr. A. F. Hertz and Dr. A. E. Barclay). The fundus of the stomach, lying ^ in the # left dome of the diaphragm, contains air both in the resting and active stomach. When empty the stomach may be found to be diastolic or systolic; if systolic it is usually covered by the transverse colon, and does not present when the epigastrium is laid open. The two extremities of the stomach are its most fixed points. The cardiac extremity is loosely fixed to the diaphragm by the oesophagus, lax periesophageal tissue, and gastro-phrenic reflec- tions of peritoneum; the pyloric end is fixed to the liver and posterior abdominal wall by the gastro-hepatic omentum, by the hepatic branch of the cceliac axis and the tissue surrounding that vessel. The close relations of the stomach to the diaphragm and thoracic viscera serve in^ part to explain the shortness of breath and possible pal- pitation of the heart, etc., that may follow upon distension^ of the organ (Fig. 75, p. 376). ^ The near proximity of the heart to the stomach is illus- trated by a case where a thorn (of the Prunus spinosa), J an inch long, had been swallowed and had then found its way through the diaphragm and pericardium into the wall and cavity of the right ventricle. The viscus is susceptible of enormous dilatation when the pylorus is obstructed. The distended organ may reach as low as Poupart's ligament. 384 THE ABDOMEN AND THE PELVIS [Chap. The stomach rests behind on the lesser sac of the peritoneum, which plays the part of a bursa to it. Gastric ulcers rarely perforate into the lesser sac, but when they do the contents can only escape by the foramen of Winslow, and may not be seen when the abdomen is opened. The sac is opened by incising the great omentum at the greater curvature of the stomach. The stomach has been frequently wounded. In most cases a fatal result rapidly follows upon these injuries, for the contents of the stomach escape into the peritoneal cavity and set up an acute peritonitis. The most certainlv and rapidly fatal cases, therefore, are those in which the stomach was full of food at the time of the acci- dent. The empty stomach, t being deeply placed and lying against the posterior abdominal wall in a collapsed state, is but little exposed to injury. A small punctured wound of the stomach need not be followed by escape of contents, since the loosely attached mucous membrane may escape from the wound and effectually plug it. This was illustrated many times in the Boer War, the viscus having been perforated by a Mauser bullet. The stomach has protruded through wounds in the abdominal walls, and has been returned, with no evil results following. In a few cases the belly wall in front of the stomach has been wounded, the viscus has protruded, its anterior wall has been wounded by the same injury that penetrated the parietes, anda fistulous opening leading into the stomach cavity ^ has resulted. The best ex- ample of such cases is afforded by the well-known instance of Alexis St. Martin, the subject of so many physiological experiments. In this man the abdominal parietes in front of the stomach were torn away by a gunshot wound, a part of the an- terior wall of the stomach sloughed, and a per- manent fistula resulted. Dr. Murchison reports the case of a woman in whom a gastric fistula was produced by the continued pressure^ of a cop- per coin worn over the epigastric region. This XVII 1 LYMPHATICS OF THE STOMACH 385 coin was deliberately worn by the patient in order to excite a lesion that would arouse the sympathy of her friends. The pressure led to an ulcera- tion that finally opened up the stomach. In many cases the fistula has been due to ulcerative diseases commencing in the stomach itself and spreading outwards. Some remarkable cases have been recorded where foreign substances have been swallowed and have lodged in the stomach. Certain of these cases serve to illustrate the capacity^ of the stomach, and among the most striking is an in- stance where the viscus^ at death was found to contain thirty-one entire spoon-handles, each about 5 inches long, four half-handles, nine nails, half an iron shoe-heel, a screw, a button, and four pebbles. The whole mass weighed 2 lb. 8 oz. Th^ patient was a lunatic. Lymphatics of the stomach. — The stomach is abundantlv supplied with lymphatics, which com- mence in the mucous coat and form plexuses in the submucous and muscular strata, from which efferent vessels pass to glands along the lesser and greater curvatures. By these vessels primary cancers of the stomach spread, _ and hence their connexions become of surgical importance. The distribution of the glands connected with the stomach is shown in Fig. 78. The chief group — the coronary — is situated near the oesophageal orifice and along the upper part of the lesser curvature. The afferent vessels of this group are shown in Fig. 78; the efferent vessels pass^ with the coronary artery to the suprapancreatic group behind the lesser sac and near the origin of the cceliac axis from the aorta. The subpyloric group is situated below and behind the pylorus. It receives afferent vessels from glands along the greater curvature (right gastro-epiploic), and from the pylorus and duodenum; its efferent vessels pass with the hepatic artery to the suprapan- creatic aroup, and some also end in the superior mesenteric group at the origin of the superior N 386 THE ABDOMEN AND THE PELVIS [Chap mesenteric artery. The efferent vessels of the subpyloric group are joined by the lymphatics from the liver (see Fig. 78). (Jamieson and Dobson.) Gastrotomy and gastrostomy. — Gastrotomy con- sists in opening the stomach through the an- Fig. 78. — The groups of lymphatic glands connected with the stomach. {Prof. J. K. Jamieson and Mr. J. F. Dobson.) terior abdominal wall for the purpose of removing a foreign body, for making an examination, or for dealing with a simple or malignant ulcer; gastrostomy, in opening the stomach in a like situation with the object of establishing a gastric fistula through which the patient may be fed in cases where the gullet is occluded by disease. The uncovered part of the stomach, accessible in these XVII] THE PYLOEUS 387 operations, is represented by a triangular area, bounded on the right by the edge of the liver, on the left by the cartilages of the eighth and ninth ribs, and below by a horizontal line passing between the tips of the tenth costal cartilages (Fig. 75). The incision in these operations must be situate in this triangle, and may be made either parallel to and about two fingers' breadth from the free border of the costse, or along the left semilunar line. In the former incision the three flat muscles of the abdomen are cut through. In gastrostomy the stomach is not opened at the time of the operation, but is merely secured to the wound, and a few days are then allowed to elapse so that adhesions may form. At the end of this time the viscus is opened. The opening must needs be very small. The pylorus is normally in a closed state, and should, when open, be capable of taking the forefinger. In spite of the narrowness of the pylorus, large substances that have been swallowed have been passed by the anus without trouble. Among these may be noted a metal pencil-case, 4j inches long, 10 ounces of garden nails, and fragments of crockery-ware swallowed by a lunatic; a fork, a door-key, and other strange bodies. Needles and similar sharp sub- stances that have been swallowed have travelled out of the stomach or bowels m and have found their way to the surface at various points in the body. In a patient under my care at the London Hospital I extracted from beneath the skin, near the groin, a needle swallowed some months pre- viously. In a case reportedin the Lancet a needle was extracted from the middle of the thigh six months after it had been swallowed; and like instances are recorded elsewhere. Hypertrophy may take place in the pyloric sphincter, leading to the functional stenosis of the orifice. It occurs soon after birth, and its cause has to be sought for in the reflex mechanism which regulates it. It is not easy to tell when the 388 THE ABDOMEN AND THE PELVIS [Chap. sphincter is hypertrophied, because the thickness of the circular layer depends on the degree of contraction at death. In a normal child of three months the circular layer of the sphincter varies from 1 to 2 mm. in thickness at the pylorus, and extends along the pyloric canal for 25 mm. (1 inch) ; if the thickness is over 3 mm. the sphincter may be regarded as hypertrophied (L. Mackey). Relaxation of the sphincter normally follows when the chyme expelled from the stomach has been neutralized in the duodenum. Resection of the pylorus. — The pylorus is fre- quently the seat of cancer. As a means # of re- lieving the patient, the whole of the > diseased pylorus has been removed, and the divided ends of the stomach and duodenum united by^ sutures. The situation of the cancerous pylorus within the abdomen varies considerably, as the diseased part is very apt to shift its position. It is often found to have sunk down by its weight to a point below the umbilicus, and to have contracted adhesions to adjacent organs. The diseased part has to be isolated and the omental connexions of the right end of the stomach freely # divided. The vessels that are almost certainly divided are the pyloric, the gastro-epiploica dextra, and the gastro-duo- denal. The operation has not been attended with much success. The cancer is apt to become diffuse, to spread to adjacent tissues, and to lead to early lymphatic invasion of the greater and lesser omenta and of the suprapancreatic glands. Gastrectomy. — Considerable portions of the stomach have been excised in cases of cancer, and the entire organ has been removed (total gastrec- tomy) for the same cause. Up to the time of writing, some fifteen examples of this operation have been recorded, with more or less immediate death in five. In Schlatter's first case of gas- trectomy, performed in 1897, the patient died in fourteen months from secondary deposits. Ricord published a case in which he removed the whole stomach, the first piece of the duodenum, and XVII] GASTRIC OPERATIONS 389 part of the pancreas. The patient was alive and well eleven months after the operation (Gaz. des Uopitaux, March 22nd, 1900). There is difficulty in uniting the gullet to the small intestine; both vagi nerves are divided as they emerge through the diaphragm, and the solar plexus is apt to be roughly handled. Other operations on the stomach. — Many other operations are performed upon the stomach which call merely for mention in this place. One of the most useful and the most frequently per- formed is gastrojejunostomy. Here an opening (or stoma) is made between the stomach and the upper part of the jejunum. An opening has also to be made in the transverse meso- colon in order that the bowel may be applied to the posterior aspect of the stomach. In making the opening the middle colic artery and its larger branches are to be avoided. The operation is per- formed in cases of stenosis of the pylorus, in cases of dilatation of the stomach without much stenosis, in certain examples of ulcer, and in many other conditions. In the operation of pyloroplasty, a non-malignant stricture of the pylorus is divided and the pyloric passage thus made free. In gastroplication certain conditions of dilated stomach are dealt with by taking in a fold or pleat in the stomach wall and in thus lessening its capacity. Small intestine.* — The average length of the small intestine in the adult is 22j feet, the extremes being 30 feet and 15 feet, the length, to a considerable extent, depending on the degree of contraction of the longitudinal muscular coat. In the foetus, at full term, the lesser bowel mea- sures about 9j feet. It is roughly reckoned that the first 8 or 9 feet of the adult bowel belong to the jejunum, and the remaining 12 or 13 feet to the ileum. The division into jejunum and ileum is quite arbitrary. There is no one point where it * The account of the intestines is based upon the Author's work "On the Intestinal Canal and Peritoneum in Man." London, 1885. 390 THE ABDOMEN AND THE PELYIS [Chap. can be said that the jejunum ends and the ileum commences. When the small intestines are ex- posed by accident or operation, it is often diffi- cult, especially when there is abdominal disease, to recognize the upper from the lower part of the gut. It may be noted, however, that the jejunum is wider than the ileum (its diameter being J of an inch greater than that of the ileum), and its coats thicker and more vascular. If the gut be empty, and can be rendered translucent by being held against a light, the lines of the valvulse conniventes can be well seen. These folds are large and numerous in the jejunum, but become small and scanty in the upper ileum, and are wanting in the lower third of that bowel. . The coils of small intestine occupy no cer- tain position in the abdomen. In the foetus, and during the earliest part of extra-uterine life, the bulk of the small intestine is placed to the left of the middle line. This is on account of the re- latively large size of the liver, to the weight of which the lesser bowel no doubt acts as a counter- poise. ^ In the majority^ of adult bodies the small intestine is disposed in an irregularly curved manner from left to right. The gut, starting from the duodenum, will first occupy the contigu- ous parts of the left side of the epigastric and umbilical regions; the coils then fill some part of the left hypochondriac and lumbar regions; they now commonly descend into the pelvis, reappear in the left iliac quarter, and then occupy in order the hypogastric, lower umbilical, right lumbar, and right iliac regions. Before reaching the latter situation they commonly descend again into the pelvis. Much interest attaches to the coils of small intestine that are found in the pelvis. These are the coils that are apt to become involved and ad- herent in cases of pelvic peritonitis, and that would probably form the protrusion in most cases of obturator, sciatic, and pudendal hernia. No small intestine occupies the foetal pelvis. The XVII] THE SMALL INTESTINE 391 amount found in the adult pelvis depends mainly upon the state of distension of the bladder and rectum, and upon the position of the sigmoid flexure. The coils that are most usually found in this position belong to the terminal part of the ileum, and to that part of the intestine that has been already alluded to as possessing the longest mesentery (p. 374). The ileum is the part of the intestine that is most frequently found in inguinal and femoral hernise. It is also the part most usually involved in cases of strangulation by internal bands, by holes in the mesentery, etc. Of all the viscera the small intestines are the most exposed to injury, and at the same time it must be noted that by their elasticity, and by the ease with which their coils slide over one another and so elude the effects of pressure, they are the best adapted to meet such injuries as contusions and the like. A minute punctured wound of the small gut does not lead to extravasation of con- tents. The muscular coat contracts and closes the little opening. Thus, in excessive tympanites the bowels are often freely punctured in many places with a fine capillary trocar, to allow the gas to escape, without any evil resulting. A case of intestinal obstruction of sixteen weeks' duration is reported, in which the abdomen was punctured 150 times (Boston Med. Joum.). If the wound be a little larger the loose mucous membrane be- comes everted or protruded through the wound and effectually plugs it. Gross observed that a longitudinal^ cut in the small bowel 2j lines in length was immediately reduced to a wound 1| lines in length by muscular contraction, and that the eversion of the mucous membrane in addi- tion to this contraction entirely sealed the open- ing. Even the opening made in the intestine — for example, in the jejunum — by the penetration of a Mauser bullet may be attended by no escape of contents. A contracted empty piece of bowel becomes nearly twice as long when distended. Owing to the greater power of the circular 392 THE ABDOMEN AND THE PELVIS [Chap. layer of muscle a longitudinal wound gapes more than a transverse wound, and, in consequence of the greater muscular development of the jejunum, wounds of that part gape more than do those of the t ileum. Transverse wounds gape most when inflicted across the free border of the gut, since in that place the longitudinal muscular fibres are thickest. In one remarkable case a man was stabbed in the belly. It was subsequently found that there was a small puncture in the ileum, which had been plugged by the mucous membrane and further secured by recent lymph. The man did well until the fourth day, when he died somewhat suddenly. It was then found that an intestinal worm (Ascaris lumbricoides) had worked its way through the wound, breaking down the adhesions, and had escaped into the peritoneal cavity. Ex- travasation followed, and thus the worm was the immediate cause of the man's death. The calibre of any portion of the small in- testine depends mainly upon the condition of its muscular wall. The tube may become much con- tracted when empty. In peritonitis and in cer- tain other conditions the muscular coat is para- lysed and the bowel becomes intensely dilated by gas (tympanites). Meckel's diverticulum. — From one to four feet from the end of the ileum is sometimes seen a diverticulum (Meckel's) (Fig. 79) that represents the remains of the vitello-intestinal duct (p. 340). It may be expected in 2 per cent, of the bodies examined. This diverticulum usually exists as a tube of the same structure as the intestine. Its length varies. It may sometimes extend as a patent tube as far as the umbilicus. It is more often but a few inches long, and may then end in a free conical or globular extremity, or in a fibrous cord. This diverticulum may cause in- testinal obstruction in many ways. Its end may contract adhesions, and beneath the bridge thus formed a loop of bowel may be strangled. It may XVII] MECKEL'S DIVERTICULUM 393 twist itself about a piece of intestine so as to form a knot round it. It may, from its adhesions, so drag upon the ileum as to cause " kinking " of the tube at its point of origin. In more than one case it has been found in an external hernia. It may become invaginated and start an intussus- ception of the bowel. # The lumen of the gut is often considerably diminished at or near the site Vitelline Duct- M ECKELS QiVERTIC. Fig. 79. — Diagram to show Meckel's diverticulum, the re- mains of the vitello-intestinal duct, and of the artery to the yolk sac. of the diverticulum, and at this narrowing in- tussusception of the bowel may commence. A loop of bowel may be strangulated over the remains of a patent vitello-intestinal duct (Fig. 79). The duct, if complete, ends at the umbilicus. The artery of the yolk sac may also persist, ^and form a cord between the mesentery of the ileum and the umbilicus, and over this a loop of bowel may become strangulated. A short cord may pass from the mesentery of the ileum to the fundus of the diverticulum, and between this and the diverticulum a knuckle of 394 THE ABDOMEN AND THE PELVIS [Chap bowel may become incarcerated. Such a cord may arise in three ways : (1) from the proximal part of the artery of the yolk sac, (2) from the free border of a mesentery with which the diverti- culum may be provided, and (3) by the elongation of an inflammatory adhesion between the apex of the diverticulum and the mesentery (Fig. 79). Duodenum and fossa duodeno = jejunalis,— The first portion of the duodenum is nearly horizontal. It measures about 2 inches in length and passes backwards from the pylorus to near the upper end of the right kidney. The second portion, about 3 inches in length, descends vertically in front of the inner border of the right kidney to the level of the third lumbar vertebra. The third portion, some 5 inches in length, crosses from right to left in front of the third vertebra, and then ascends for a short dis- tance on the surface of the left psoas muscle, to end in the jejunum to the left of the second lumbar vertebra (Fig. 75, p. 376). The first por- tion, which is movable, is invested by peritoneum in the same manner as the stomach. The second part is covered by peritoneum in front only, ex- cept at the spot where it is crossed by the trans- verse colon. The third part is also covered by peritoneum on its anterior aspect only, this mem- brane being, however, free of the gut where the superior mesenteric vessels cross it. A constric- tion, probably functional in nature, is usually found at the termination of the third stage. The end of the duodenum, the duodeno- jejunal bend, is very firmly held in place by a band of fibro-muscular tissue that descends upon it from the right crus of the diaphragm and the tissue about the cceliac axis. This band is called the suspensory muscle of the duodenum (Treitz). It serves also to support the mesentery. In ptosis of the viscera the neck of the pancreas and duodeno- jejunal bend are the least displaced^ parts be- cause of their attachment to the posterior wall by the fibrous tissue round the cceliac axis and origin XVII] BRUNNER'S GLANDS 395 of the superior mesenteric artery. All sections of the duodenum have been ruptured by violence. Owing to its large non-peritoneal surface, the bowel, if approached from behind, may be wounded without opening the peritoneum. Brunner's glands occur in the first stage of the duodenum; their secretion probably protects this part of the gut against the acid chyme which is only neutralized as it reaches the second stage. It is probably because of the nature of its con- tents that the first stage of the duodenum is so frequently the site of ulceration ; over 90 per cent, of duodenal ulcers occur in the first stage (Collin). The ulcer may perforate and the contents escape into the subhepatic space, or adhesions may form to surrounding organs — the gall-bladder, the liver, the head of the pancreas, the right kidney, or the hepatic flexure of the colon. Very frequently small diverticula of the mu- cous membrane are formed at the point where the common bile - duct perforates the muscle coat of the duodenum. They are often large enough to take the first joint of the forefinger, and occur especially in cases of ptosis of the viscera. In the newly born a complete occlusion of the duodenum may be found just above the entrance of the common bile-duct. Passing from the front of the terminal (as- cending) part of the duodenum, a fold of peri- toneum is often seen, that joins the parietal peritoneum to the left of the piece of gut in ques- tion. This fold marks off a fossa of triangular outline, the orifice of which is directed upwards. I have found the fossa in about 50 per cent, of the bodies examined. It is called the fossa duodeno=jejunalis; it is usually large enough to lodge the tip of the finger, and its opening lies just below the duodeno-jejunal bend (Fig. 80). Besides the lower fold, there is often also an upper, so that the fossa^ is bounded both above and below by a crescentic margin. In the natural state of parts, the fossa is filled by 396 THE ABDOMEN AND THE PELVIS [Chap. the terminal part of the duodenum; the fossa is only apparent when the duodenum is arti- ficially displaced. The inferior mesenteric vein ascends near the left margin of the pocket. This fossa is the anatomical cause of mesen- teric, mesocolic, mesogastric, or retroperitoneal hernia. The commencement of the jejunum presses into the fossa, enlarges its cavity, and ultimately 'InJeHo r\m esefi ter[ic ^ DUODENAL FOLD Fig. 80. — The fossa duodeno-jejunalis. separates the peritoneum from its posterior at- tachments. More and more of the small intestine passes into the increasing pouch, until at last, as in the case reported by Sir Astley Cooper and in many others, nearly the whole of the small intes- tine may be found lodged in an enormous median retroperitoneal sac, the mouth of which is the orifice of the fossa duodeno-jejunalis. The duo- denum can be seen to enter the sac and the end of the ileum to leave it. The sac usually extends XVII] OPERATIONS ON SMALL INTESTINE 397 downwards on the left side, and may reach the promontory of the sacrum. These hernise vary in size, but are as a rule large. The csecum and ascending colon have their normal position, but the transverse and descending parts of the colon are stretched over and displaced by the sac. The renal artery is behind the hernia, and the in- ferior mesenteric artery is in front of it and to the left. A branch of this vessel, the colica sinis- tra, is near to the orifice of the sac in its lower part. Numerous modifications occur in the form and boundaries of this peritoneal fossa, and a hernia may enlarge in any direction, but usually towards the left, where it passes behind the left margin of the fossa containing the inferior mesenteric vein. Operations on the small intestine. — Enterotomy is the operation of opening the small intestine above some obstruction that threatens to be fatal or insuperable. A knuckle of bowel, above the obstruction, is secured to the wound in the ab- dominal wall, and opened. The small intestine has also been opened to remove impacted foreign bodies and large gall-stones. In such cases the intestinal wound is closed immediately. F uterectomy. — Parts of the small intestine have been > resected with success for various diseased conditions^ In one case more than two yards of the small intestine were cut away on account of multiple stricture. The patient, a young woman, made an excellent recovery. Resections have also been successfully performed in cases of bullet wound or stab involving the lesser bowel, and in other injuries. Tumours of the gut have been removed by a partial resection. Non-malignant strictures of the bowel have been treated by in- cision and dilatation. The bowel above an obstruction has been con- nected to the bowel below an obstruction by the operation called intestinal anastomosis or short- circuiting. Experience shows that if leakage occurs after 398 THE ABDOMEN AND THE PELVIS [Chap. resection or suture of intestine it will most likely occur along the attachment of the mesentery. This circumstance is thus explained by Mr. An- derson : The two layers of the mesentery diverge as they approach the bowel, and so leave a tri- angular space, the base of which, averaging about ■^ths of an inch in width, is formed by the un- covered muscular tissue. It is the existence of this bare piece of intestine that renders adjust- ment of the serous coat at the attachment of the mesentery a matter of some difficulty. Heo-csecal region. — The caecum is, to a cer- tain extent, rudimentary m in man, as it is also in the carnivora. In herbivorous animals it is of great size, and appears to serve as a reservoir for the elaboration and absorption of food. It has been said that the caecum in man exists as an anatomical protest against vegetarianism. The appendix persists as the remains of the larger caecum of lower mammals. In the human foetus it can be seen to be but the narrowed ex- tremity of a capacious caecum. The foetal type of caecum, which is very characteristic, may per- sist throughout life. < From the point of view of evolution the appendix would appear to be becom- ing obliterated. Like other functionless parts that persist as developmental relics, it is very fre- quently the seat of disease, and it is worthy of note that such disease tends to cause the entire obliteration of the part (as after many forms of so-called appendicitis). It must be understood that the term ccecum is applied to that part of the colon which lies below the entrance of the ileum. The average breadth of the adult caecum is 3 inches, its average length (vertical measurement) 2j inches. These measure- ments apply to the organ as seen in the- cadaver ; in the living it is constantly changing its shape according to its state of physiological activity. The caecum normally contains gas, and gives a high, tympanitic note on^ percussion ; Glenard found that in cases of ptosis of the viscera it was XVII] ILEO-CiECAL REGION 399 often contracted, and when palpated had the consistency of a sausage. . . The caecum is usually lodged in the right iliac fossa, and is so placed that its apex corresponds with a point a little to the inner side of the middle of Poupart's ligament. When distended with gas or faecal contents it occupies the whole of the right iliac fossa. The ileo-caecal orifice is situated immediately below the spino-umbilical ILEOCOLIC FOSSA BLOODLESS FOLD ILEO-CWBCAL F036A Fig. 81.— The peritoneal fossee of the ileo-caecal region. line and externally to Monro's point (see Fig. 75, p. 376). A slightly distended caecum so located may be emptied by flexing the thigh upon the abdomen. The caecum is always entirely invested by peri- toneum. Its posterior surface is never in con- nexion with the areolar tissue of the iliac fossa. The peritoneum is reflected from the commence- ment of the ascending colon on to the posterior parietes below the level of the iliac crest. A mobile caecum may hang over the pelvic brim, or occupy the pelvis, or even find its way into an inguinal hernia of the left side. The caecum is not infrequently found in an inguinal or femoral hernia of the right side (caecal hernia). Such herniae are, except in a few rare instances, provided with 400 THE ABDOMEN AND THE PELVIS [Chap. a proper and complete peritoneal sac. Foreign bodies that~ have been swallowed are very apt to lodge in the caecum, and in that situation may cause ulceration and even perforation of the bowel, producing one form of typhlitis. In cases of faecal retention, also, the largest accumulation of faecal matter is very usually met with in the caecum,^ and upon that part of the bowel when distension is extreme the greatest strain usually comes. Stercoral ulcers (ulcers due to the pres- sure and irritation of retained faeces) are more often met with in the caecum than in any other part of the colon. Solitary follicles are numerous in the mucous membrane of the caecum, especially near the ileo-caecal orifice. Intestinal concretions also are not uncommon in this part. Three kinds of movement occur in the caecum : (1) a churning movement, which has been ob- served to commence within an hour of taking food; (2) antiperistaltic movements, which begin in the colon and end in the caecum; (3) pro- pulsive or emptying movements. Water is ab- sorbed, and the faeces commence to assume a solid consistency as they reach the transverse colon. The ileo-caecal orifice is guarded by a muscular sphincter (ileo-ccecal sphincter) ; it is innervated by the sympathetic system and regulates the escape of chyme from the ileum (Elliot and B. Smith) : Sir William Macewen has seen it in action in the case of a soldier in whom a wide caecal fistula resulted from a gunshot injury. The same observer has also seen a secretion escaping from the mouth of the appendix, which is situated about 1 inch below the ileo-caecal orifice. The appendix varies in length. Its average measurement in the adult is 4 inches, the extremes being 1 inch and 6 inches. Its position varies, although, as a rule, it is seen to lie behind the nnd of the ileum and its mesentery, and to point in the direction of the spleen. It frequently also lies behind the caecum. I have seen the appendix so placed with reference to the bowel that it would XVII] THE APPENDIX 401 have been encountered in a right lumbar colotomy. In such cases the appendix has been pushed be- hind the caecum and caught in the mesocolon during the later months of foetal life, when the colon migrates from the neighbourhood of the liver to the right iliac fossa.^ The appendix may hang within the pelvis and, in inflammatory con- ditions, contract adhesions to the ovary or other pelvic structures. I have found an inflamed ap- pendix adherent to the liver, and another in the left iliac fossa. It has found its way down both the right and the left inguinal canals. The tip of the process may adhere to a neigh- bouring peritoneal surface, and thus form a 44 band," beneath which a piece of small intestine may be strangulated. The mesentery of the appendix (Fig. 81), which contains an artery derived from the ileo-colic, may be so short as to produce obstructive kinks in the appendix. The mucous lining is so crowded with solitary lymphoid follicles as almost to oc- clude its lumen. Like other lymphoid structures these^ follicles begin to atrophy soon after adult life is reached. In some forms of appendicitis these follicles are involved. Lymphatics of the caecum and appendix (Fig. 82). — Since in inflammation of the appendix infection spreads chiefly by its lymphatics, the arrangement of this system is of surgical im- portance. As in other parts of the alimentary canal, there are three plexuses of lymphatics : (1) a submucous, which receives the lymph from the mucous membrane ; (2) an intermuscular plexus; (3) a subserous plexus. All three are in the freest communication. The lymphoid follicles are situated in the submucous plexus; at breaks of the muscular coat the submucous and subserous plexuses are in direct continuity; hence infection may readily spread to the peritoneal coat, setting up peritonitis. The efferent vessels pass chiefly into the meso-appendix, where one or more glands may occur, but most of the efferent vessels pass 402 THE ABDOMEN AND THE PELVIS [Chap. to the ileo-colic group of glands situated in the ileo-colic angle (Fig. 82). This group also receives lymphatics from the anterior part of the caecum and base of the appendix by vessels which pass through the anterior colic fold. Vessels from the posterior aspect of the caecum also join the ileo- colic group. These vessels do not communicate with the lymphatics of the iliac or lumbar regions (Jamieson and Dobson). The vessels which issue Ileo-Colic Vessels Ascend. Colon Mesentery of Appendix Fig. 82. — The course of the lymphatics of the caecum, appendix, and colon. (After Jamieson and Dobson. ) from the ileo-colic group of glands join the efferent vessels of the small intestine and of the ascending colon, and enter glands situated along the superior mesenteric artery. It is in the ileo-caecal region that intussuscep- tion most frequently occurs. In this condition one part of the intestine is prolapsed or "tele- scoped " into the lumen of an immediately adjoin- ing part. In the ileo-caecal variety (the common- est form) the narrow ileum, and subsequently the caecum, are prolapsed into the colon. The ileo- XVII] BATE OF PROGRESS OF FOOD 403 caecal orifice forms the summit of the protrusion or intussusceptum. In the ileo-colic variety (the rare form) the end of the ileum is prolapsed through the valve. The orifice and the caecum remain in their normal situations, and the sum- mit of the intussusceptum is formed only by the ileum. In another variety, which is also common, the apex of the intussusceptum is formed by the fundus of the invaginated csecum. There are three fairly constant peritoneal fossae, which are sometimes the seat of hernia, in the ileo-caecal region (Fig. 81). They are (1) the ileo-colic, situated between the ascending colon and termination of the ileum; a fold containing the anterior caecal artery bounds it^ above; (2) the ileo-caecal fossa, between the termination of the ileum and the caecum; it is bounded in front by the bloodless fold and behind by the mesentery of the appendix; (3) the retrocaecal fossa, behind the caecum ; it is bounded on the right by the lower termination of the ascending mesocolon. Rate at which the contents of the alimentary canal progress. — A study of the movements of a bismuth-laden diet along the alimentary canal of the living materially modifies the conception one forms of the bowel from an examination of this part in the dead. The account given here is founded chiefly on the observations of Dr. A. F. Hertz. The contents of the stomaeh begin to pass into the duodenum very soon after food is taken ; in 4j hours the food begins to enter the caecum, which gradually fills. In 6 J hours the^ bismuth-laden contents have reached the hepatic flexure, and in 9 hours the splenic flexure. In the ascending colon and first part of the transverse colon the fluid part of the faeces is^ absorbed. The progress along the descending iliac and pelvic colon is slow. In 30 hours the bismuth diet is lodged in the iliac and pelvic colons. Although faeces are t occasionally lodged in the rectum, in the majority of people this is only the case during defaecation. The colon 404 THE ABDOMEN AND THE PELVIS [Chap. must be regarded not as a passive tube, but as an active muscular organ concerned in propulsion as well as absorption. JLarge intestine. — From the csecum to the sigmoid flexure, this portion of the bowel is accessible to pressure except at the hepatic and splenic flexures, which are deeply placed. The hepatic flexure is under the shadow of the liver, and the splenic curve, which reaches a higher level, is behind the stomach (Fig. 75, p. 376). The position of the transverse colon can often be well marked out. It crosses the belly transversely, so that its lower border is nearly on a level with the umbilicus (Fig. 75). In cases of faecal accu- mulation, the outline of the colon, with the exception of the two flexures above named, may be distinctly defined. In distensions of the small intestine the belly tends to present the greatest degree of swelling in front, and about and below the navel. In distension of the larger gut, the front of the abdomen may remain (for a while at least) comparatively flat, while the distension will be most obvious in the two flanks and in the region just above the umbilicus. Tumours of the transverse colon, and of the lower two-thirds of the ascending and descending colon, can be well defined, even when of moderate size, and in cases of intussusception the progress of the mass along the colon can often be traced with great ease, and the effects of enemata and other methods of re- duction carefully watched. The diameter of the large intestine (excluding the rectum) gradually diminishes from the csecum to the sigmoid flexure, the diameter of the former being about 2j inches, of the latter lj inches. The narrowest part of this segment of the bowel is at the point of junction of the sigmoid flexure with the rectum, and it is significant that this is the point at which stricture is the most common. The tendency to stricture increases as one pro- ceeds downwards from the csecum to the anus. A stricture is frequent in the descending colon, less XVII] LAEGE INTESTINE 405 frequent in the transverse colon, while in the ascending colon it is comparatively rare. Stric- tures are not uncommon about the flexures of the bowels.* The ascending and the descending colon are placed vertically. The average length of the as- cending colon in the adult (as measured from the tip of the caecum to the hepatic flexure) is 8 inches. The average length of the descending colon (from the splenic bend to the commencement of the sig- moid flexure) is 8j inches. The descending colon is very little liable to variation, and is always found in a semi-contracted condition. That part of the descending colon which lies in the left iliac fossa, from the iliac crest to the left psoas muscle, is now distinguished as the iliac colon. In cases of non-descent of the caecum the ascend- ing colon may be absent (p. 401). I have pointed out that in 52 per cent, of adult bodies there is neither an ascending nor a descending mesocolon, and that a mesocolon may be expected on the left side in 36 per cent, of all cases, and on the right side in 26 per cent. These points are of importance in connexion with the some- what uncommon operation of lumbar colotomy. The breadth of the mesocolon, when it exists, varies from 1 to 3 inches. The line of attach- ment of the left mesocolon is usually^ along the outer border of the kidney, and is vertical. That of the right mesocolon is, as a rule, less vertical, runs along the outer border of the kidney, and crosses its lower end obliquely from right to left. The transverse colon has an average measure- ment of 20 inches. It is not quite horizontal, since the splenic flexure is on a higher level than the hepatic flexure, as well as posterior to it, and always shows a number of bends, one occurring near its commencement and another near its end. Faecal masses lodged in the transverse colon have given rise to many errors in diagnosis. In some ? See "Intestinal Obstruction," by the Author. London, 1899. 406 THE ABDOMEN AND THE PELVIS [Chap. instances this part of the colon is displaced to- wards the pelvis, so that V or U-shaped bends are produced. In such cases the point of the V or U may reach the symphysis pubis, while the two colic flexures occupy their proper situations. These deviations are described in detail in my work on Intestinal Obstruction. The sagging and elongation of the transverse colon indicate a loss of tone and of contraction in its muscular coat, especially of the longitudinal taeniae. There is a corresponding relaxation in the muscular walls of the abdomen, so that the normal support is withdrawn from the abdominal viscera. The peritoneal supports of the hepatic and splenic flexure become stretched and appear to compress and obstruct the free passage of the colic contents. The constipation in such cases appears to be due, not to the kinking and compression of the colon, but to the primary relaxation of the colic mus- culature, the cause of which is still obscure. The right-hand part of the transverse colon is in intimate relation with the gall-bladder, and is commonly found to be bile-stained after death. In some cases where gall-stones have been lodged within the gall-bladder, the walls of that struc- ture have ulcerated from pressure, the ulceration has involved the subjacent transverse colon, and thus a fistula has been established between the gall-bladder and the gut, through which large stones have been passed. Hepatic abscesses also have discharged themselves through the trans- verse^ colon. The transverse colon often finds its way into an umbilical hernia, and has been found to be concerned in many of the cases of hernia into the foramen of Winslow. The sigmoid flexure. — The segments of gut termed the sigmoid flexure and " the first part of the rectum " form together a single simple loop that cannot be divided into parts. This loop begins where the iliac colon ends, and ends at the commencement of the so-called " second part of the rectum " ; at a spot, in fact, where the meso- XVII] SIGMOID FLEXURE 407 rectum ceases, opposite about the third piece of the sacrum. This loop, when unfolded, describes a figure that, if it must be compared to a letter, resembles the capital Omega fl. It may well be termed the Omega loop, and the term rectum be limited to the short piece of practically straight gut that is now described as the second and third parts of the rectum. By the majority of anato- mists and surgeons the Omega loop is now named the " pelvic colon, ;; although at birth and fre- quently in the adult it is not pelvic in position. The average length of the loop in the adult is 17| inches. The two extremities of the loop are about 3 or 4 inches apart. If they are approxi- mated to one another, as by contracting peri- tonitis at the root of the sigmoid mesocolon, a kind of pedicle is established, about which the loop may readily become twisted. Such a twist of the bowel constitutes a volvulus of the sigmoid flexure ; and it may be here said that volvulus of the intestine is more commonly met with in this loop than in any other part of the canal. The line of attachment of the mesocolon of the Omega loop (the sigmoid mesocolon) crosses the left psoas muscle and the iliac vessels near their bifurcation ; it then turns abruptly down, and running nearly vertical, terminates at the middle line. In the left wall of this mesocolon, close to the point where it lies over the iliac vessels, a fossa is sometimes to be found. It is produced by the sigmoid artery, and is about lj inches in depth. It is called the intersigmoid fossa, and is the seat of sigmoid hernia (Fig. 83, mc). Two cases of strangulated hernia in this fossa have been recorded. The sigmoid flexure, or Omega loop, when empty, normally occupies the pelvis. When dis- tended this piece of bowel may become so enor- mously dilated as to reach the liver. The chief examples of extraordinary dilatation of the colon concern this loop. Fsecal masses are very 408 THE ABDOMEN AND THE PELVIS [Chap. frequently lodged in the free end of the loop, and certain intestinal concretions have been met with in the same situation. I have shown by experiment that the " long tube," when introduced through the anus, cannot Fig. 83. — Sigmoid flexure turned upwards to show the intersigmoid fossa. \(Jonnesco.) S. F, Sigmoid flexure ; as, sigmoid artery ; MC, mesosigmoid fossa ; a e, external iliac artery ; u, ureter in front of internal iliac vessels. be passed beyond the sigmoid flexure in ordinary cases and with a normal disposition of the bowel. In cases of congenital absence or deficiency of the rectum, the sigmoid flexure is often opened in the groin and an artificial anus established there. This operation, known as Littre's opera- tion, is, it must be confessed, not very successful. XVII] ii LABGE INTESTINE 409 One difficulty has been said to depend upon the uncertain position of the sigmoid flexure in cases of congenital deformity, it being sometimes on the right side a^id sometimes in the pelvis at the middle line. It is rarely, however, found in these positions. Out of 100 post-mortem examinations on young infants, Curling found the loop on the left side in eighty-five cases. Out of ten children who were operated on for imperforate anus, the loop was found in the left fossa in only one case (Montgomery). The iliac and pelvic colons are often the seat of multiple diverticula of the mucous coat. These diverticula occur at points where vessels enter or emerge from the bowel, thus giving rise to weak points in the muscular coat through which the mucous coat forms small hernias or diverticula. They protrude within the appen- dices epiploicse and root of the mesentery. This part of the colon serves as a receptaculum for the faeces, and is always tonically contracted, and this is probably the reason why the pelvic colon is more frequently the seat of these diver- ticula than any other part of the bowel. The section of the body shown in Fig. 84 gives the immediate relations of the descending colon, and the structures to be^ cut through if the sur- geon wishes to expose this structure in the loins. The position of the descending colon in the loin may be represented by a line drawn vertically upwards from a point on the iliac crest 1 inch external to the outer border of the erector spinse. An incision is made across the centre of this line parallel to the last rib, and so planned that the centre of the incision corresponds to the centre of the line. The superficial tissues having been in- cised, the following structures are divided in layers in the order here given (Fig. 84) : (1) The latissimus dorsi and external oblique muscles to an equal extent ; (2) the internal oblique in the entire length of the incision ; (3) the fascia lum • borum, with a few of the most posterior fibres 410 THE ABDOMEN AND THE PELVIS [Chap. of the transversalis muscle; (4) the transversalis fascia. The quadratus lumborum will be exposed in the posterior inch or so of the incision, and Fig. 84. — Horizontal section through the body at the level of the umbilicus. {After Braune.) a, Spine of the fourth lumbar vertebra ; b, disc between third and fourth vertebrae ; c, umbilicus ; d, quadratus lumborum ; e, psoas ; /, external oblique, with internal oblique and transversalis muscles beyond ; g, rectus ; h, descending colon ; i, transverse colon ; 3, aorta ; A-, inferior vena cava ; I, ureter. usually does not need to be cut. At the seat of the operation the descending colon occupies the angle between the psoas and quadratus lumborum muscles, and the non-peritoneal surface is exactly XVII] COLOTOMY 411 represented by that part of the bowel that faces this angle (Fig. 84). Thus, if during the opera- tion the curved finger be placed in this angle, and the patient be rolled over to the left side, the bowel that falls into the finger cannot well be other than the descending colon. The width of the non-peritoneal surface varies from fths of an inch to 1 inch in the empty state, and may attain to 2 inches or more in the distended condition (Braune). Iliac or inguinal colotomy. — - In this very common, excellent, and simple operation the sig- moid flexure is exposed and opened in the left iliac region. A line is drawn from the anterior superior iliac spine to the umbilicus, and an in- cision some 2 inches in length is made at right angles to this line and at a distance of about lj inches from the point of the bone. The three muscles of the abdomen and the peritoneum hav- ing been divided, the loop of the sigmoid flexure is brought into the wound, is secured, and is (at once or at a later period) opened. The ascending branch of the deep circumflex iliac artery crosses the line of the incision. The iliac colon is bound by a very short mesentery to the iliac fossa, but, owing to the mobility of the peritoneum in this region, the bowel is easily brought into the wound. The csecum may be opened on the right side, and as a rule the most convenient incision is an oblique one placed externally to the deep epigastric artery. The appendix has also been opened and sutured to the incision in the groin (appendi- costomy). Through the opening in the appendix the caecum and colon may be irrigated and washed out. Colectomy consists in excising a -portion of the colon. The csecum has been removed, and con- siderable segments of the rest of the large in- testine. ^ The treatment of ^ cancer of the colon by excision is attended with considerable suc- cess. Portions of the ascending and descending 412 THE ABDOMEN AND THE PELVIS [Chap. parts of the colon have been excised through an incision in the loin, but colectomy is much more readily carried out through an anterior wound. I have reported a case in a young girl, in which I excised the whole rectum and anus, the sig- moid flexure, and the whole of the descending colon. The divided transverse colon was broughi out at the anus. The child made a perfect re- covery. The parts removed are in the Museum of the Royal College of Surgeons. The operation of intestinal anastomosis or short-circuiting is very frequently practised on the colon. Thus, in an obstruction of the descending colon impossible of removal, the transverse colon may be unitec to the sigmoid flexure. In more recent years Mr. Arbuthnot Lane has applied excision of the great bowel to cases of obstinate constipation which are unrelieved by medical measures, especially to those cases where the transverse colon is greatly elongated and kinked (see p. 406). In cases of obstinate colitis the great bowel may be " rested " by uniting the lower part of the ileum to the pelvic colon, thus short-circuiting the food passage. The results of such operations are often favourable, and have been cited in support of the theory, promulgated by Metchnikoff, that the great bowel is a useless and dangerous structure in man. The evidence, so far as it goes, indicates that no colon is better than a diseased colon, but it certainly does not signify that no colon is better than healthy one. Congenital malformations of the colon.— These are of moment with regard to m operative procedures. It may be very briefly said that in the foetus the small bowel occupies at one time the right side of the abdomen, while the large gut is represented by a straight tube that passes on the left side vertically from the region of the umbilicus to the pelvis. ^ The caecum is at first situated within the umbilicus, and then ascends in the abdomen towards the left hypochondrium. It XVII] MALFORMATIONS OF COLON 413 next passes transversely to the right hypochon- drium, and then descends into the corresponding iliac fossa. It may be permanently arrested at any part of its course. # Thus the caecum may be found about the umbilicus, or in a congenital umbilical hernia, or in the left hypochondriac region (the ascending and transverse parts -of the colon being absent), or it may be found in the right hypochondrium, the ascending colon only being unrepresented. The whole of the large intestine has at one time an extensive mesentery, and in some rare cases this condition may persist throughout life. When it does persist, it may lead to one form of volvulus of the bowel. CHAPTER XVIII THE ABDOMINAL VISCERA (concluded) The liver. — The liver is moulded to the arch of the diaphragm, and lies over a part of the stomach (Fig. 85). Properly speaking, it has only two surfaces — a visceral surface, which in the upright posture rests on the stomach, duodenum, gastro-hepatic omentum, neck of the pancreas, hepatic flexure of colon, right kidney, and right suprarenal body; and a parietal surface, in con- tact with the diaphragm and anterior belly wall in the subcostal angle. As seen from the front it is triangular in outline, with its apex near the apexofthe heart (Fig. 85); its upper border is best indicated by a line commencing at the apex beat (Fig. 85) and passing across the mid line 1 an inch^ below the sterno-ensiform point; it ascends as it reaches the nipple line to the level of the sterno-ensiform plane. The lower border com- mences at the apex beat, crosses the mid line about 1 inch above the mid-epigastric point, reaches the costal margin at^ the outer border of the rectus, and the remainder of its lower border corresponds to the costal margin as far as the tip of the eleventh rib. The liver is in contact with the right kidney along the lower margin of that rib (Fig. 89). For surgical purposes the liver in the right hypochondrium may be regarded as made up of three zones — an upper or pulmonary, a middle or pleural, and a lower or diaphrag- matic (Fig. 85). In the lower zone, which is l\ to 414 Chap. XVIII] THE LIVER 415 2 inches wide in the mid-axillary line, the liver may be incised or explored; in the middle zone, which is of equal width, the pleural reflection is encountered. In the erect posture the lower edge on the right side is about J or J of an inch below the margins of the costal cartilages. In the re- cumbent position the liver ascends about an inch, 'J STEBflO-EflSIF. LlrtE Apex Poi/it ^PuLNONABy LIWE _i Pleural Li/ie TIepatic Duct Cystic Duct £ pancreas -duode/ium /I id Epigastric Li/ie IPylop-US +5T0WACM .Comaio/i5ileDuct ±DuODEflU/1 .^ Liaiea Alba J U/iBILICAL U/1E Lt/1EA5EA»ILUA1ARI3 Fig. 85.— Diagram showing the position of the liver, gall- bladder, bile-ducts, and pancreas. The lower limits of the pleura and lung are indicated. and is entirely covered by the costse, except at the subcostal angle. It descends also in inspiration and rises in expiration. The fundus of the gall-bladder approaches the surface behind the ninth costal cartilage, close to the outer border of the right rectus muscle (Fig. 85). Its position is extremely variable ; it fre- quently occupies a position considerably below and external to the one mentioned. 416 THE ABDOMEN AND THE PELVIS [Chap. The liver is retained in shape by, and moulded upon, the diaphragm above and the abdominal organs below. When removed from the body the shape is lost which it possesses clinically. It pre- sents many variations in form. One of the com- monest is a linguiform process, usually known as Riedel's lobe, which projects from the margin of the right lobe under the tenth costal cartilage (Fig. 76, p. 378). It is found more frequently in women than in men, and may be mistaken for a floating kidney or an abdominal tumour. In the condition known as ptosis of the 'liver the organ slides from the dome of the diaphragm, and may descend to the level of the umbilicus or reach the iliac fossa (Fig. 76). With the descent there is also a rotation on its transverse axis, so that its dianhrasrmatic surface comes almost com- pletely to the front. In such a case the factors which maintain the liver in position have to be considered. They are : (1) its fixation to the diaphragm by the inferior ^ vena cava and the fibrous tissue on the non-peritoneal posterior sur- face of the right lobe in the neighbourhood of the inferior vena cava. (2) The peritoneal folds, which include the right and left lateral, coronary, and falciform ligaments, also attach it to the diaphragm. These folds are lax, in order to allow the free movements of the liver which occur during respiration and in the filling and emptying of the stomach. (3) The muscular abdominal walls. These keep the other abdominal viscera constantly pressed against the lower surface of the liver. The muscles constitute the chief means for main- taining the liver in position. ^ In many women over 40 the right lobe of the liver projects quite 2 inches below the 11th rib, and, as in the child* the extremitv of the left lobe frequently comes in contact with, or even overlaps, the upper part of the snleen. The liver is more often ruptured from con- tusion than is anv other abdominal viscus. This is explained by Tts large size, its comparatively XVIII] INJURIES TO THE LIVER 417 fixed position, its great friability of structure, and the large quantity of blood contained in its vessels. A normal liver will take its own weight of blood if its veins be injected at ventricular pressure (Salaman). Death in such injuries usually ensues from haemorrhage, since the walls of the portal and hepatic veins, being incorpo- rated with the liver substance, are unable to re- tract or to collapse. The hepatic veins also open direct into the vena cava, and, being unprovided with valves, could allow of the escape of an immense quantity of blood, if any retrograde current were established. The hepatic vessels are thin-walled, and it is almost impossible to ligature them, except by buried sutures. It is possible for the liver to be ruptured without the peritoneal coat being damaged; and such injuries may be readily recovered from. The liver pre- sents, behind, a fairly extensive non-peritoneal surface, at which rupture or wound may occur without extravasation into the abdominal cavity. From the relation of the liver to the right lower ribs, it follows that this viscus may be damaged when the ribs are fractured, and in some cases the broken ends of the bones have been driven through the diaphragm into the liver substance. Stabs through the sixth or seventh right inter- costal space, over the liver region, would wound both the lung and the liver, would involve the diaphragm, and open up both the pleural and peritoneal cavities. The intimate relation of the liver to the transverse colon is illustrated by a case where a toothpick, 4 inches in # length, was found in the substance of the liver. It had worked its way there, from the colon, alon§ an abscess cavity that connected the two viscera. _ The relation of the liver to the heart may be illus- trated by a case still more remarkable. In this instance a loose piece of liver, weighing 1 drachm, was found in the pulmonary artery. The patient had been crushed between two wagons, o 418 THE ABDOxMEN AND THE PELVIS [Chap. the liver was ruptured, and the diaphragm torn. A piece of the liver had been squeezed along the vena cava into the right auricle, whence it had passed into the right ventricle, and so into the pulmonary artery. The heart itself was quite uninjured. Portions of the liver may protrude through abdominal wounds, and are usually easy to reduce. In one instance of such protrusion the surgeon did not find the reduction easy, so he placed a ligature round the projecting part of the viscus, and then cut this obstinate portion of the liver off. The patient recovered. Con- siderable portions of the liver have been removed with success. It is remarkable from what grave injuries of the liver recovery is possible. Thus, Dr. Gann {Lancet, June, 1894) reports the case of a man of 28, who had a harpoon driven through the whole thickness of the right lobe of the liver, so that it projected at the posterior border. The blade was 7 inches long, and had two barbs. It was removed by operation twenty-eight hours after the accident, and the patient made a good recovery. From a reference to the relations of the liver it will be readily understood that an hepatic abscess may open into the pleura, and in some cases, indeed, the pus from the liver has been discharged from the bronchi. Thus, it has been possible for a patient to cough up some portion of his liver, although, of course, in a very disintegrated and minute form. Hepatic abscess may burst in one or other of the following directions, placed in order of their frequency : (1) into the right lung; (2) into the bowel; (3) upon the surface of the body. Such abscesses have, in rare cases, opened into the stomach. The liver is very frequently the seat of the secondary abscess of pyaemia, and, according to Mr. Bryant's statistics, abscesses in this viscus are more common after injuries to the head than after injuries elsewhere. They are rare in pyaemia following affections of the urinary organs, and are equally rare in the pyaemia after XVIII] THE GALL-BLADDER 419 burns. Secondary deposits of tumours and ab- scesses are frequently limited to the right or to the left of a line drawn from the fundus of the gall-bladder to the inferior vena cava. This re- markable limitation is to be explained by the fact that the liver to the .right of this line is supplied only by the right terminal division of the portal vein, while the part to the left receives blood only from the left division (Cantlie). The gall-bladder may be absent, as is the case with some animals, or reduced to a cicatrix from disease. It is often removed by operation, and no disturbance in the biliary function is apparent (Moynihan). Its mucous membrane has a peculiar reticulated, honeycomb appearance, and is made up of columnar epithelium, which secretes mucus and has a power of absorption. When inflamed the cells pour out a morbid amount of secretion, in which the cholesterin of the bile may become deposited if the outflow is obstructed, and may form the nuclei of gall-stones. These are composed mostly of cholesterin, a normal con- stituent of bile, and vary in size from a hemp seed to a hen's egg. The escape of gall-stones is rendered more difficult by the presence of a spiral fold of mucous membrane in the neck and duct of the gall-bladder. The gall-bladder, at its neck, forms an acute angle with the cystic duct, the spiral fold being necessary to keep the passage open. In the erect position the long axis of the gall-bladder is directed upwards and backwards, and the cystic duct downwards and forwards (Fig. ^ 85). The cystic duct lies in the gastro- hepatic omentum, where it joins the hepatic to form the common bile-duct. It is accompanied by the cystic^ artery. The cystic veins pass directly into the liver and end in the portal capillary sys- tem^ m In cases of cystitis the part of the liver receiving the cystic veins is seen to be contracted or atrophied. A gall-stone may be arrested in, and require removal from, any part of the cystic or common 420 THE ABDOMEN AND THE PELVIS [Chap. bile-ducts. The common bile-duct is 3 inches long, and its lumen £th of an inch wide, but by the pas- sage of the gall-stones it may become three times its normal diameter. The upper half of the com- mon bile-duct lies in the gastro hepatic omentum, in front of the foramen of Winslow, with the portal vein behind it and to the right. The hepatic artery lies close to it on the left, and its branch, the superior pancreatico-duodenal, crosses the common bile-duct as it passes to its second or deeper stage. A stone arrested in the lower half of the duct is difficult of access. The duct lies buried between the head of the pancreas be- hind and the duodenum in front and to the outer side. It may be necessary in such a case to open the duodenum and extract the stone through its posterior and inner wall, or the duodenum and head of the pancreas may be turned forwards from the inner border of the right kidney, thus expos- ing the lower half (post-duodenal stage) of the common bile-duct in the groove between the duo- denum and pancreas. The terminal half-inch is embedded in the wall of the duodenum and ends in the ampulla of Vater. At its termination, where the duct is narrowest, it is surrounded by a sphincter which regulates the flow of bile. The lumen of the lower half of the duct is less than that of the upper half. Two lymphatic glands lie in the gastro-hepatic omentum by the side of the bile-duct, and have been mistaken for gall- stones when calcified. The gall-bladder receives its nerve supply from the eighth and ninth segments of the cord (Head) through the great splanchnic and coeliac plexus. The intense colic caused by gall-stones, believed to be due to spasm of the non-striated muscular coat of the bile-ducts, is reflected along^ the ninth dorsal nerve to the anterior abdominal wall. Stimulation of the sympathetic nerves causes the muscle of the cystic duct to contract, but relaxes that of the gall-bladder (T. R. Elliot). The con- tractions of the musculature of the biliary system xvim THE GALL-BLADDER 421 are correlated with the movements of the stomach, and hence are liable to occur soon after taking food (Lynn Thomas). The gall-bladder and the bile-duct have been ruptured alone without rupture of the liver. The injury is rapidly fatal, owing to the escape of bile Inferior Vena Cava Ster/io-E/isiform Line Fundus orbionAcn Liver Oesopnaqeal Orifice SPLEEN Pulmonary Line qnt Suprarenal /Iid-epicastric Line Pleural line Pelvis of Kidney qnt Kidney ector. spinae scendimc Colon uadr.atu5 luhborum Umbilical Line RETER POST. Sup Iliac Spine Fig. 86. — The position and relationships of the abdominal viscera from behind. The lower limits of the pleura and lung are shown in red. into the peritoneal cavity. Large gall-stones may be passed direct into the bowel through a fistulous track that has been established between the gall- bladder and the intestine. Gall-stones have sup- purated out through the anterior belly-wall, and have been removed from abscesses in the parietes. Thus Dr. Burney Yeo reports a case where more 422 THE ABDOMEN AND THE PELVIS [Chap. than one hundred gall-stones were discharged through a spontaneous fistula in the hypogastric region, 5 inches below the umbilicus. In cases where the bile-duct is occluded by gall-stones, or by other causes, the gall-bladder may become enormously distended, and may form a tumour extending some way beyond the umbilicus. So large a tumour has been formed that the mass has Fig. 87. — Horizontal section through upper part of abdomen. (Riidinger.) a, Liver ; b, stomach ; c, transverse colon ; d, spleen ; e, kidneys ; /, pancreas, f/, inferior vena cava; h aorta with thoracic duct hehind it. been mistaken for an ovarian cyst. The gall- bladder as it enlarges tends to follow a line extending from the ^ tip of the right tenth car- tilage across the median line of the abdomen below the umbilicus. For the relief of this condition, cholecystotomy, or incision into the gall-bladder, has been performed. In this operation the in- cision or puncture is made over the most promi- nent part of the tumour. Impacted gall-stones XVIII] THE SPLEEN 423 have been removed entire from the bile-duct through an incision so made, or the stone has been crushed in situ and extracted in fragments. In cholecystectomy the whole of the gall-blad der is excised and the cystic duct closed. The bile finds its way into the intestine direct through the common duct. In cholecystenterostomy a fistula is established between the gall-bladder and the intestine. The operation is carried out in cases in which there is an insuperable obstruction in the common duct. The gall-badder thus takes the place of the com- mon duct. The spleen. — The spleen is deeply situated in the left hypochondriac region, and in the normal condition cannot be palpated, being quite covered in front by the cardiac end of the stomach (Fig. 87). It most closely approaches the surface^ in the parts covered bv the tenth and eleventh ribs. Above this it is entirely overlapped by the edge of the lung. It is in all parts separated from the parietes by the diaphragm. " It lies very obliquely, its long axis coinciding almost exactly with the line of the tenth rib. Its highest and lowest points are on a level, respectively, with the ninth dorsal and first lumbar spines; its inner end is distant about \\ inches from the median plane of the body, and its outer end about reaches the mid-axillary line" (Quai-n) (Fig. 86). It pos- sesses three surfaces, gastric, renal, and phrenic, well shown in Fig. 87 . A dislocated or floating condition of the spleen is rare. Its renal surface is fixed firmly to the upper half of the^ left kidney ; its gastric surface is kept in apposition to the stomach by the gastro- splenic omentum ; its upper pole is attached near the cardiac orifice of the stomach by a suspen- sory fold of peritoneum, while its lower rests on the costo-colic peritoneal fold, and has the tail of the pancreas and colon in contact with it. The tension of the ^ abdominal walls exerts a general pressure on it through the other abdominal 424 THE ABDOMEN AND THE PELVIS [Chap. organs. When the spleen enlarges, as in ague, ite crenated anterior border may be felt beneath the tenth costal cartilage. The movable or floating spleen is met with only in adults. The organ may be so displaced as to reach the iliac fossa. Injuries.— Although extremely friable in struc- ture, the normal spleen is not very frequently ruptured. Its connexions, indeed, tend to mini- mise the effects of concussions and contusions. When the spleen, however, is enlarged, it is very readily ruptured, and often by quite insignifi- cant violence. Thus, several cases have been re- corded of rupture ofan enlarged spleen by mus- cular violence. For instance, a woman ruptured her spleen in an attempt to save herself from fall- ing, and another in^ springing aside to avoid a blow. The patients in each instance were natives of India, and the latter case gave rise to a charge of homicide. The spleen being extremely vas- cular, it follows that ruptures of the viscus are usually, but not necessarily, fatal from haemor- rhage. It is well to note, in connexion with this matter, that the spleen contains most blood during digestion. A case is reported, however, of a boy who met with an accident just after dinner, and who managed to walk some distance, although his spleen, as the autopsy revealed, was separated into three portions. He lived some days. In severe fractures of the ninth, tenth, and eleventh ribs the spleen may be damaged and lacerated. The capsule of the spleen contains muscular tissue, and must possess some contractile power. This f act # may serve to explain cases of recoverv from limited wounds of the organ, such as small gunshot wounds. In such lesions the capsule may contract and greatly narrow the hole in the viscus, while the track of the bullet or knife may become filled with blood-clot, and the bleeding thus be staved. The spleen may be greatlv enlarged in certain diseased conditions. The hypertrophied spleen may attain such dimensions as to fill nearly the XVI11J THE PANCREAS 425 whole abdomen, and in one case a cystic tumour so completely occupied both iliac fossae that it was mistaken for an ovarian cyst, and the operation for ovariotomy was commenced. Extirpation of the spleen has been successful in cases of abdominal wounds with protru- sion of the viscus. It has also been performed with fair results in many cases of hypertrophied spleen, and of wandering spleen. The operation is not justifiable in cases of leuksemic enlargement of the organ, it having proved invariably fatal in such instances. In cases of wounds with pro- trusion, the spleen is, of course, removed through the wound. The splenic artery, with its large accompanying vein, lies in the lieno-renal liga- ment, in contact with the tail of the pancreas below. The pancreas lies behind the stomach, in front of the first and second lumbar vertebrae (Fig. 85). It crosses the middle line behind the mid-epigastric line (Fig. 85). In emaciated sub- jects, and when the stomach and colon are empty, it may sometimes be felt on deep pressure, espe- cially in those who are the subjects of visceroptosis ; prolapse of the stomach leaves the pancreas ex- posed above the lesser curvature. It is in relation with many most important structures. So closely is it mixed up with the solar plexus that this structure is necessarily involved in inflammatory conditions, and must be disturbed in any operative procedures on its head and neck. It has, I be- lieve, never been ruptured alone, and it could scarcely be wounded without the wound implicat- ing other and more important viscera. It has been found herniated in some very rare cases of diaphragmatic hernia, but never alone.^ The main duct (duct of Wirsung) usually terminates with the common bile-duct in the ampulla of Vater (Fig. 88, a), so that a gall-stone arrested at this point may occlude both ducts or possibly cause a reflux of the bile within the pancreatic duct. Not uncommonly (in 30 per cent, of cases) the o * 426 THE ABDOMEN AND THE PELVIS [Chap. ampulla is partly (Fig. 88, b) or completely divided (Fig. 88, c), so that the orifices of the two ducts are separated ; in such cases occlusion of the termination of the bile passage leaves the pan- creatic duct free. A secondary duct (the duct of Santorini) is present in a more or less de- veloped condition in 50 per cent, of subjects. It may form a connexion with the main duct, as in Fig. 88, A, or be merely a minute ductule, as in Fig. 88. — Diagrams to show the variations in the manner of termination of the pancreatic and bile-ducts. A, Form in which the common bile-duct (C, B, D) and main pan- creatic duct (B) end in an ampulla (E). A, Duct of Santorini ; i., ii., iii., first, second, and third stages of the duodenum. B, Form in which the ampulla is partly divided. The duct of San- torini is shown in its reduced form. C, Form in which the common bile-duct and pancreatic duct have separate openings into the duodenum. The duct of Santorini is absent. Fig. 88, b. . The accessory duct opens nearer the pylorus, being § of an inch above the ampulla of Vater. The ampulla usually extends into a papilla which projects within the duodenum, but this papillated condition is not always present. Septic conditions may spread from the duodenum to the pancreas or gall-bladder by means of their ducts. The common bile-duct in its second stage lies between the head of the pancreas and the duo- XVIII] ISLETS OF LANGEKHANS 427 denum. It thus happens that in carcinoma of this part of the gland the duct may become en- tirely occluded and jaundice result. Or the duo- denum and even the colon may be more or less obstructed by pressure, or the neighbouring vessels be closed. Cancer of the pylorus may spread to the head of the pancreas by direct extension. The lymphatics of the two parts also freely communicate. The pancreas lies behind the lesser sac of the peritoneum, its anterior surface being covered by the posterior wall of the sac. It lies in front of the aorta, in the fork between the coeliac axis above and the superior mesenteric artery below. The portal vein passes upwards behind the neck of the gland. Islets of Langerhans. — When microscopic sec- tions of the pancreas are examined, numerous small groups of cells are observed among the normal acini of the gland. These islets of Lan- gerhans are acini of the gland which have become modified to form an internal secretion (Swale Vincent). They vary in number from 300to 400 (M. A. Lane). The pathological proof ^ is now definite that destruction of these islets gives rise to diabetes (Mayo Robson). The kidney. — The relations of this organ are as follows : — In front. Right. Left. Visceral surface of liver. Fundus of stomach. Second part of duodenum. Descending colon. Commencement of transverse colon. Pancreas. Ascending colon. Spleen. Externally. Liver. Kidney. Externally. Spleen. Behind. Lower part of arch of diaphragm. Quadratus lumborum. Psoas. Transversalis. ast rib and transverse processes of upper two lumbar vertebra-. 428 THE ABDOMEN AND THE PELVIS [Chap. The kidneys are deeply placed, and cannot be felt or distinctly identified when normal. They are most accessible to pressure at the outer edge of the erector spinae, just below the last rib (Figs. 86 and 89). The dullness of the right kidney merges above in that of the liver, while on the left side it is impossible to distinguish between the dullness of the kidney and spleen. The right kidney lies usually lower down than does the left; but even the lower pole of the right kidney is an inch above the crest of the ilium, or — what for practical purposes is the same level — above the umbilical line (Fig. 75, p. 376). The simplest manner of indicating the position of a kidney is to mark out the position of the upper and lower pole and between those two points mark on the well-known form of the kidney. The lower pole of the right organ lies about \ an inch outside the prominent lateral border of the erector spinae and 1 inch above the iliac crest (Fig. 86); since the kidney is about 4 inches long and is situated obliquely — its long axis corresponding to that of the 12th rib — its upper pole is sufficiently in- dicated by taking a point* 4 inches above and 1^ inches internal to the position of the lower pole. The spine of the 11th dorsal vertebra — which may be identified when the patient bends by its anti-clinal direction and semiiumbar form — is just below the level of the upper pole. On an average the left kidney lies \ an inch higher than the right (Addison). In many instances in the female its lower end reaches the iliac crest, and may even go below it. Such positions are much less common in the male. The hilum lies about 2 inches from the middle line, and is opposite to the 1st lumbar spine and usually in the gap between the transverse processes of the 1st and 2nd lumbar vertebrae (Fig. 86). In radiograms of the injected ureter the shadow of the pelvis of the kidney is seen to fall across those of the transverse processes just mentioned, and also that of the last rib (Fig. 90). XVIII] THE KIDNEY 429 The anterior surface is but slightly covered by peritoneum, being only in contact with that mem- Fig. 89. — Showing the relationshipsiof thejkidney and colon in the lumbar region from behind. (Adopted from 3ferkel.y P.L., Lower line of pleura ; XI., eleventh rib ; XII., twelfth rib ; 12th d.n., twelfth dorsal nerve; 1st l.n., ilio-inguinal and ilio-hypo- gastric nerves : A.B., vertical line representing position of descend- ing colon (desc. c.) ; Q.L., quadratus lumborum ; E.S., erector spinse ; peritoneum (perit.) is shown reflected from the front of the kidney to the colon on the right side. brane in such parts as are not in relation with the cellular tissue at the back of the colon and at * The kidneys are represented in the position they assume when the body is turned on its face ; in the supine position they fall inwards and backwards into the position described in the text. In the subject figured above, the 12th rib is shorter than is common. 430 THE ABDOMEN AND THE PELVIS [Chap. the back of the duodenum or pancreas. The ex- ternal border is more closely in connexion with the peritoneum, while the posterior surface is quite devoid of that membrane (Figs. 86 and 87). Crossing the posterior surface of the kidney obliquely from above downwards and outwards are branches of the last dorsal nerve and of the first lumbar artery, together with the ilio-hypo- gastric and ilio-inguinal nerves (Fig. 89). Rupture of the kidney is more often recovered from than is a like lesion of any other of the more commonly injured abdominal viscera. This depends upon its extensive non-peritoneal surface, whereby the extravasation of blood and urine that follows the accident is very often entirely extra- peritoneal. The gland may be readily wounded from behind or from the loin, without the peri- toneum being injured. When the spine is much bent forwards, the kidney lies in the angle of the bend, at a part where the flexion of the column is the most acute. In extreme flexion, therefore, of the spine, it may be squeezed betweenthe ilium and the lower ribs. Thus, hematuria is not un- common after injuries to the back associated with extreme bending of the spine forwards, as when a heavy weight falls upon the bowed shoulders. The kidney is embedded in a large quantity of loose fatty tissue constituting the perirenal capsule, and suppuration extending in this tissue constitutes a perinephritic abscess. Such an ab- scess may be due to disease of the kidney itself, to affections of the adjacent parts (spine, colon, etc.), or to injuries. The pus is at first in front of the quadratus lumborum, and then usually makes its way through that muscle or through the lumbar fascia. It then presents itself at the outer edge of the erector spinse, having passed between the adjacent borders of the ex- ternal oblique and latissimus dorsi muscles. It may, however, spread into the iliac fossa, or ex- tend into the pelvis along the loose connective XVIIIj MOVABLE KIDNEY 431 tissue behind the descending colon and rectum, or open into the colon or bladder, or even into the lung. Most rarely of all does it perforate the peritoneum. Renal abscess usually opens upon the non-peritoneal surface of the gland. It may open into the adjacent colon. In one case a renal abscess, due to stone, made its way from the right kidney into the pyloric end of the stomach, so that a communication was established between those two organs. The perirenal fat is of much surgical importance, as its laxity permits of a ready enucleation of the organ. It is more abund- ant behind than in front. When this tissue has been destroyed or modified by inflammation, the kidney becomes fixed, and its removal a matter of great difficulty. This is illustrated by the re- moval of a large tuberculous kidney which has been long diseased. Besides the perirenal cap- sule, the kidney also possesses its proper capsule, which can be easily stripped from the normal organ. The blood pressure in the renal vessels renders the capsule tense ; in inflammatory con- ditions the tension may become so great as to interfere with the free passage of blood through the kidney. Incision of the capsule has been proposed to relieve such congested conditions. Movable kidney. — The kidneys, being closely applied to the diaphragm, necessarily follow its respiratory movements; in normal breathing the up and down excursion of the kidney is about i an inch in extent. The perirenal capsule in which the kidney is loosely embedded is merely a specialized part of the subperitoneal connective tissue. The parts of the perirenal capsule have been artificially separated into prenephric and postnephric fascice Joy Zuckerkandl. Above, the perirenal capsule is continuous with the dense subperitoneal tissue on the diaphragm, externally with the equallv dense layer over the transversalis, internally it fuses with the sheaths of the in- ferior vena cava and aorta, while below it is continued downwards, as the lax subperitoneal 432 THE ABDOMEN AND THE PELVIS [Chap. tissue surrounding the ureter, to become con- tinuous with the corresponding tissue in the pelvis. Hence only downward displacements are possible. The perirenal capsule and the renal vessels, while they restrict and determine the direction of the renal movements, only come into action when the normal limits have been exceeded. The force which retains the kidneys in position is the intra-abdominal tension maintained by the musculature of the abdominal wall, by which the other viscera are compressed against the kid- neys. With the absorption of fat from the cap- sule the tissue of the perirenal capsule becomes more lax and the renal movements more free. Hence movable kidney is often met with in the badly nourished. It is far more common in women than in men. In the former sex the influ- ence of pregnancy appears to have especial effect, acting, probably, by dragging upon the peri- toneum, and by loosening its connexions, as well as by inducing, after delivery, a general laxity of the abdominal walls. The right kidney is far more often movable than is the left, owing prob- ably to the displacing influence of the liver. I have recorded (in conjunction with Dr. Mac- lagan) three cases in which a movable kidney pressed against the neck of the gall-bladder and obstructed the flow of bile. The movable kidney can, of course, only be displaced within a seg- ment of a circle whose radius corresponds to the length of the renal vessels, and yet this displace- ment may be considerable. The dragging pains which are felt with a movable kidney are due to a stretching of the renal plexus, which is connected with the solar plexus and enters the kidney with the arteries. The kidney receives its nerve supply from the 10th, 11th, 12th dorsal, and 1st lumbar segments of the spinal cord through the small and lesser splanchnics (Head). Pain is referred to the wall of the abdomen along the sensory nerves derived from these segments. XVIII] MISPLACED KIDNEY 433 Abnormalities of the kidneys.— One, or loss frequently both kidneys may be misplaced. The left is more often out of place than the right, and may be found over the sacro-ihac synchon- drosis, or the promontory of the sacrum, or be discovered in the iliac fossa or pelvis. The mis- placed kidney is often misshapen. The kidney may exhibit ' a more or less extreme degree of Upper Pole of Kidney ■Dilated Pelvis Abnormal Art. Fig. 89a. — An abnormal renal artery causing kinking at the uretero-pelvic junction, and hydronephrosis. {After Hurry Fen wick.) lobulation, a condition present in the newly born. The ureter may be double in its upper part or throughout its whole extent, there being two ureteral orifices in the bladder. Supernumerary arteries are frequently present; cases have been recorded where such vessels, passing to the lower pole of the kidney, have caused constriction or kinking of the ureter, and hydronephrosis. In a series of cases of hydronephrosis, Mr. Hurry Fenwick found that the kinking of the ureter 434 THE ABDOMEN AND THE PELVIS [Chap. was due to an abnormal vessel in 16 per cent, of cases (Fig. 89a). The kidneys are developed in the pelvic region, and ascend in the early months of foetal life to a lumbar position. New renal vessels are formed as the ascent takes place. The "sacral" kidney is one which has been arrested in its ascent, and the blood supply is drawn from the common iliac arteries. Double ureter is due to a division of the primary renal bud. The two kidneys may be fused. " The lowest degree of fusion is seenin the horse-shoe kidney. The two kidneys are united at their inferior por- tions by a flat, riband-like, or rounded bridge of tissue, which crosses the vertebral column. In the higher degrees the two lateral portions approach one another more and more until they reach the highest degree, in which a single disc-like kidney, lying: in the median line, and provided with a double or single calyx, represents complete fusion" (Eokitansky). When the two kidneys are united by a web of connective tissue, the condi- tion is no bar to operation. There may be an entire absence of one kidney. The single kidney may be lateral or median in position. Sir Henry Morris gives the following estimate of the fre- quency of these abnormal conditions : Congenital absence or extreme atrophy of one kidney may be expected in about one in 4,000 cases, the horse- shoe kidney in one in 1,600, and the single fused kidney in one in 8,000 cases.* . Operations on the kidney, — (1) Nephrotomy. Incision into the kidney for exploration, or the evacuation of pus. (2) N ephro-lithotomy. In- cision into the gland for the removal of a calculus. (3) Nephrectomy. Removal of the entire organ. (4) N ephrorrhaphy. ^ The operation^ of securing a movable kidney in its normal position. In the first, second, and fourth operations the kidney * For fuller details regarding abnormalities of kidneys, see " Urinary Surgery," by F. S. Kidd. XVIII] RELATIONS OF KIDNEY 435 Sup. LohcSihus i/ihomihate art. Trachea Oesophagus Vena Azyqos Major Right Luhc Thoracic Duct Diaphragm l£_R'CMT KlD/iEY Ureter Spermatic Vessels Ihf. Veha Cava Bifurcation op Aorta Cluteus/^edius Psoas Rectum Sup. /Iaemorrh.Art. Gluteus Maximus Fig. 90.— View of the kidneys, etc., from behind. {After Riidinger.) 43G THE ABDOMEN AND THE PELVIS [Chap. is reached through the loin. In nephrectomy the incision is carried backwards about 1 inch over the erector spinse, and a part of the quadratus lumborum will be divided (see Fig. 89). The costo-vertebral ligament, a specialized part of the middle layer of the lumbar fascia which binds the last rib to the tips of the upper two lumbar transverse processes, also falls in the line of the incision. The perirenal capsule is opened up, and the gland enucleated from the capsule of fat in which it lies. In some instances the last rib has been resected to obtain more space for the operation. The pleura reaches the neck of the 12th rib and occasionally it descends as far as the transverse process of the 1st lumbar vertebra (Figs. 86 and 89). In one case the 12th rib was rudimentary, and the 11th rib was removed under the impression that it was the 12th. The pleura was opened and death ensued. When the kidney is free from its fatty capsule, the vessels at the hilum are secured separately by ligatures. The numerous nerves to the kidney are no doubt included with the vessels. They con- stitute a surgical pedicle of the kidney. At the hilum the vein lies in front, the artery and its branches next, and the ureter behind and towards the lower^ part. The artery is about the size of the brachial, and usually divides into four, five, or six branches before it reaches the kidney. This fact must be borne in mind if the structures at the hilum are separately secured. One-third of these branches constantly enter the hilum be- hind the ureter and are liable to injury in ex- ploration of the pelvis of the kidney. The vein is also represented at the hilum by three or four branches. Accessory renal arteries maybe present. Some may enter the upper end of the kidney or its anterior surface. In removing large renal tumours an abdominal incision is advised, the cut being made either along the corresponding semilunar line, and on a level with the diseased mass, or in XVIII] SUPRARENAL BODIES 437 the linea alba. The abdominal operation is the more usual one; it has the advantages of greater ease and rapidity in performance, and gives an opportunity of examining the condition of both kidneys. In chronically inflamed conditions of the kidney — as, for example, in long-standing tuberculous disease — the kidney becomes adherent, and on the right side is apt to become closely bound down to the vena cava. Much care is needed in clearing the great vein when so ad- herent. In removing a very adherent kidney the diaphragm has been torn. The suprarenal bodies are situated at the upper poles of the kidneys, but are more closely united to the diaphragm than to these organs, as is seen from the fact that they are not dis- placed with the kidneys. The right body lies behind the right lobe of the liver, and so close to the inferior vena cava that the two may become bound by inflammatory adhesions. They are glands which form an internal secretion (adrenalin) that is evidently concerned in regulating the tonus of non-striated muscle. When applied directly, it causes constriction of arteries and a narrowing of the bowel. The cortex of the body is developed from epithelium covering the Wolffian body, and when this body descends with the genital glands, detached parts may accompany these organs and form suprarenal tumours. Parts may also become embedded in the kidneys and give rise to peculiar renal tumours. The medulla, which arises with the sympathetic system, receives a large nerve supply from the solar plexus. Disease of the suprarenals may cause bronzing of the skin ; hence they are believed to be concerned in the formation of body pigment. The ureters are strong tubes about 15 inches long;, with thick muscular walls, and are placed entirely behind the peritoneum. The average width is that of a goose-quill. The ureter rests from above downwards upon (1) the psoas muscle and the genito-crural nerve; (2) the common iliac 438 THE ABDOMEN AND THE PELVIS [Chap vessels on the left side, and the external iliac vessels on the right; (3) after passing downwards on the internal iliac artery it then enters the posterior false ligament of the bladder, and so reaches the bladder wall. In the female it passes through the base of the broad ligament, where the uterine artery loops over it j of an inch from the neck of the uterus. It rests on the roof of the upper part of the vagina before entering the bladder, and a calculus arrested in that stage may be distinctly felt. The narrowest part of the tube is the portion within the bladder walls, and when renal calculi pass along the ureter they are often arrested at this point. There are two other narrow points at which calculi may be stopped : at its junction with the pelvis of the kidney, and where it crosses the pelvic brim. The ureters per- mit of great distension, and in certain cases of gradual dilatation they have attained a width equal to that of the thumb and even of the small intestine. Several cases are recorded of rupture of the ureter from external violence. When such an accident occurs a large urinary collection usually forms behind the peritoneum, which, lead- ing to suppuration, will produce a fluctuating tumour beneath the parietes. The ureter expands in the hilum of the kidney into a funnel-shaped cavity — the pelvis. This in turn divides into the calyces. In the pelvis or calyces, calculi are frequently lodged. The calyces are too narrow to admit an exploring finger. The ureter has been successfully resected and sutured. It is supplied by nerves from the renal plexus and by vessels from the renal, inferior vesical and subperitoneal plexus. Its malforma- tions have been already mentioned (p. 433). In the search for impacted calculi by the aid of X-rays the following method will be found useful for indicating the course of the ureter. The pelvis of the kidney lies between the trans- verse processes of the two upper lumbar vertebrae (Fig. 91) ; its position on the surface of the body XVIII] URETERAL CALCULI 439 may be indicated by taking a point just internal to that used for the gall-bladder (p. 415). At the brim of the pelvis the ureter crosses at or near the bifurcation of the common iliac artery, a point which lies at the junction of the upper iAodtic Bifurcation Fig. 91. — Diagram to show the course of the ureters and position of the bladder, As they appear in a skiagram when they have been injected with a bismuth solution. The positions of the fundus of the uterus Fallopian tubes, and ovaries are also indicated. with the^ lower two-thirds of a line drawn from the aortic bifurcation to the femoral point (see Figs. 90 and 91, and 72, p. 352). Its pelvic course is curved (Fig. 91), the convexity of its out- ward bend lying \ an inch in front of the ischial spine. The vesical orifice is to be sought for in a skiagram at some distance above and inter- 440 THE ABDOMEN AND THE PELVIS [Chap. rial to the pubic spines. Mr. Rigby has shown that the ureter may be exposed from behind through the sacro-sciatic notch, and calculi thus removed from it, when the anterior operation is impracticable on account of pelvic adhesions. He uses the ischial spine as a guide in finding the ureter. Nerve supply of the abdominal viscera. — Some account has been given of the nerves which supply the abdominal viscera and of the spinal segments from which they are derived (p. 349). These viscera are mainly supplied by the sympa- thetic system through a series of plexuses. The most important of these is the solar, from which is more or less directly derived the nerve supply of stomach, liver, spleen, kidneys, suprarenal cap- sules, pancreas, and such parts of the intestine as are in connexion with the superior mesenteric artery. The solar plexus and its appendages re- ceive the splanchnic nerves and some branches from the vagus, while communications from the phrenic go to the hepatic and suprarenal plexuses. Through these nerves the calibre of the blood- vessels and the amount of blood in the abdomen are regulated. They contain not only sensory fibres ior the abdominal viscera but constrictor and dilator fibres for the bowel. It may be well understood that an impression brought to bear upon extensive networks with such wide central connexions and with such important relations would produce considerable effects. These effects we see in the profound collapse, vomiting, and other grave symptoms that attend severe injuries to the viscera, and especially to those that are the most directly associated with these large plexuses. The descending colon and sigmoid flexure are supplied by the inferior mesenteric plexus. The upper part of the colon, although supplied by the superior mesenteric plexus, is only supplied by that part of it that is most remote from the great centres, and it is^ a conspicuous fact that the nearer the lesion is to the stomach, the graver, XVIII 1 "SYMPATHETIC PAINS" 441 other things being equal, are the nervous pheno- mena produced. In some diseases of the liver and stomach " sympathetic" pains are complained of between the shoulders or about the inferior angles of the scapulae. They commonly appear some distance below the angle of the scapula. . The nerves for the stomach are derived principally from the seventh and eighth and those for the liver from the eighth and ninth spinal segments. The skin areas of these segments may become tender^ when the organs are diseased, and to some point in these areas pain is referred (Fig. 70, p. 345). The shoulder-tip pain that often accompanies liver disease is situated in the area supplied by the fourth cervical segment, the same segment as sup- plies sensory fibres to the diaphragm and sub- diaphragmatic connective tissue through the phrenic nerves. It will be remembered that these nerves are distributed on the under surface of the diaphragm. There would seem to be^ but^ little connexion between a disease in the sigmoid flexure and a pain in the knee, yet in cases of cancer in this flexure, and in instances where it has been dis- tended with faeces, such pain has been complained of. The pain is conveyed along the^ obturator nerve, which lies beneath the sigmoid flexure, and could be readily pressed upon by the gut when diseased. Pain arising from the small in- testine is usually referred to the neighbourhood of the umbilicus — the distribution of the tenth dorsal nerve (Fig. 70, p. 345). It seems remark- able that such pains should be restricted to so narrow an area, but a full explanation of this is to be found in the fact that the whole of the small intestine arises from an extremely small part of the embrvonic alimentary tract. Pains along the groin (along the 12th dorsal and 1st lumbar nerves) arise from many sources — from dis^ase^ of the kidnev, ureter, ovary, testicles. Fallopian tubes, uterus, appendix, hip-joint, and 442 THE ABDOMEN AND THE PELVIS [Chap. from hernise. Hence a pain referred to this region requires that all these parts should be investigated as to the source of the disease. Blood-vessels 01 the abdomen. — Some of the visceral branches of the abdominal aorta are of large size, and would bleed very copiously if wounded. Thus, the cceliac axis and the superior mesenteric artery are as large as the common carotid; the splenic, hepatic, and renal vessels are about the size of ^ the brachial ; while the largest part of the inferior mesenteric trunk has dimensions equal to those of the ulnar artery. Aneurysmsof the aorta are especially apt to occur at the cceliac axis, that being a point where a number of large branches are abruptly given off, and where the course of the circulation undergoes in consequence a sudden deviation. Although two, or in some places three, anastomotic arches occur between the branches of the superior mesen- teric artery before they form a final network in the bowel, yet embolism of a comparatively small branch may lead to gangrene of the gut (Lock- wood). When it is remembered thatthe lumbar glands lie about the vena cava and iliac veins, it will be understood that great enlargement of those bodies may cause oedema from pressure. Gan- grene of the whole of the small intestine may result from an embolism of the portal vein. In a case reported by Mr. Barnard the embolism was caused by a constriction at the point where the vein passes behind the neck of the pancreas. The inferior vena cava has been ligatured success- fully : amongst the collateral veins which enlarge, the chief are the azygos, epigastric, and intra- vertebral veins. A number of minute but most important anas- tomoses exist between some of the visceral branches of the abdominal aorta and certain of the vessels supplied to the abdominal parietes. These anasto- moses are situated behind the peritoneum and mostly concern such viscera as have a fair sur- XVIII] ABDOMINAL BLOOD-VESSELS 443 face uncovered by that membrane. The visceral branches that join the anastomoses are derived from the hepatic, renal, and suprarenal arteries, and from the vessels supplying the lower part of the duodenum, the pancreas, the caecum, and the ascending and descending segments of the colon. The parietal vessels joining with the above are derived from the phrenic, lumbar, ilio-lumbar, lower intercostal, epigastric, and circumflex iliac trunks. In a case detailed by Professor Chiene (Journ. Anat. and Phys., vol. iii.) the cceliac axis and mesenteric vessels were plugged, but blood in sufficient amount to supply the viscera had reached branches of these arteries through their parietal communications. When the portal circulation becomes obstructed owing to disease of the liver, blood from the portal vein may pass into the systemic veins at the following points : (1) lower part of the rectum, from the superior to the inferior and middle hsemorrhoidal veins; (2) at the oesophagus, from the coronary to the oesophageal veins ; (3) in the falciform and round ligaments, from the portal vein to tributaries of the epigastric; (4) in the subperitoneal tissue of the posterior wall of the abdomen, whereby the renal, phrenic, lumbar, and intercostal veins re- ceive blood from mesenteric, pancreatic, and other veins. By bringing about adhesions between the omentum or visceral peritoneum and the parietal peritoneum, as is done in the Talma-Morrison operation, new and large communications are formed between the portal and systemic venous circulations. Cases have been recorded of com- munications between the external iliac vein and the portal vein. These have generally been effected by the deep epigastric vein joining with a pervious umbilical vein in the vicinity of the navel. Thoracic duct. — The thoracic duct may be wounded in the course of removing tubercular glands f rom^ beneath the lower part of the left sterno-mastoid ; or, as in some reported cases, may 444 THE ABDOMEN AND THE PELVIS be severed by a stab in the neck. In each case lymph and chyle in large quantities escaped from the wound. The duct has been found to have been obliterated, and that, too, without pro- ducing any marked symptoms during life. It has been cut and ligatured during removal of glands from the supraclavicular triangle, with no bad result. Mr. Leaf has shown that the thoracic duct communicates freely with the azygos veins in the posterior mediastinum and with the lym- phatic vessels of the righfc side of the thorax and neck. It frequently serves as a channel for the spread of malignant tumours situated in the upper part of the abdomen. Enlargement of the inferior deep cervical glands in the left side of the neck may be the first sign of cancer of the stomach (W. M. Stevens). CHAPTER XIX THE PELVIS Mechanism of the pelvis. — Besides forming a cavity for certain viscera, a support for some abdominal organs, and a point for the attach- ment of the lower limb and of many muscles, the pelvis serves to transmit the weight of the body both in the standing and sitting postures. The transmission is effected through two arches, one available for the erect position, the other for the posture when sitting. When standing, the arch is represented by the sacrum, the sacro-iliac synchondroses, the acetabula, and the masses of bone extending between the two last-named points. If all other parts of the pelvis were to be cut away but these, the portions left would still be able to support the weight of the body, and would represent in its simplicity the arch through which that weight is transmitted. When sitting, the arch is represented by the sacrum, the sacro-iliac syn- chondroses, the tubera ischii, and the strong masses of bone that extend between the two last- named parts. Sir Henry Morris terms these two arches the femoro-sacral and the ischio-sacral. On examining the innominate bone it will be seen that its thickest and strongest parts are such as are situate in the line of these. " When very consider- able strength is requisite in an arch, it is continued into a ring so as to form a counter-arch, or what is called a tie is made to connect together the ends of the arch, and thus to prevent them from 445 446 THE ABDOMEN AND THE PELVIS [Chap. starting outwards. By these means a portion of the superincumbent weight is conveyed to the centre of the counter-arch, and borne in what is called the sine of the arch. The body and hori- zontal rami of the pubes form the tie or counter- arch of the femoro-sacral, and the united rami of the pubes and ischium the tie of the ischio-sacral arch. Thus the ties of both arches are united in front at the symphysis pubis, which, like the sacrum or keystone, is common to both arches. . . . . This explains how it is that so much strain is made upon the symphysis when any increased weight has to be supported by the pelvis, as in pregnancy ; why there is such powerlessness, with inability to stand or sit, in cases in which this joint is weakened or diseased; and why the anterior portion of the pelvis yields under the weight of the body and becomes deformed in rickets and mollities ossium. ;; * The pelvic de- formity in rickets, it may be here observed, varies greatly according to the age at which the disease sets in, and the usual attitude of the child when it becomes affected. The deformity sometimes pro- duced in very young infants has been ascribed to muscular contraction (ilio-psoas, erector spinse, gluteus medius, etc.). In the rickety pelvis, par excellence^ the two acetabula approach one an- other, the anterior part of the pelvis yields, so that the symphysis is pushed forward, and the cavity becomes greatly narrowed in its transverse diameter. In severe cases the anterior arch may practically collapse, and the horizontal rami of the pubes be for some little way parallel to one another. In the erect attitude the pelvis is so inclined that the plane of the brim of the true pelvis forms with the horizon an angle of from 60° to 65°; the base of the sacrum is about 3| inches above the upper border of the symphysis, while the tip of the coccyx is a little higher than its lower border. The centre of gravity of the whole body (adult) * Sir Henry Morris, " The Joints," p. 11(3, where a most valuable account of the mechanism of the pelvis will be found. XIX1 FKACTURES OF PELVIS 447 is at a spot just above the sacro-lumbar angle, and exactly over the mid-point of a line drawn between the heads of the femora. Fractures of* the pelvis. — From what has been already said, it may be surmised that the weakest parts of the pelvis are at the symphysis and the sacro-iliac joints. The bones of these parts, however, are so very firmly knit together by powerful ligaments that it is very rare for these articulations to give way, fracture of the adjacent bones being more common. The com- monest fracture of the pelvis is in the weak counter-arch, and involves the rami of both the pubes and the ischium. The fracture is often associated with some tearing of ligaments about the sacro-iliac synchondrosis, and is met with in accidents due to the most varied forms of vio- lence. This last remarkable circumstance is thus explained by Tillaux. If the pelvis be compressed in (a) an antero-posterior direction, the main brunt of the force comes upon the weak counter- arch, which fractures from direct violence. The force, continuing, tends to push asunder the two iliac bones, and so cause rupture of the anterior ligaments at the sacro-iliac joint. If the force be applied (b) transversely, the two acetabula tend to be pressed towards one another, the counter - arch becomes more bent, and ultimately gives way by indirect violence. The violence, continuing, forces the two ilia towards one another, the strain then falls upon the sacro-iliac synchondrosis, and the posterior ligaments of that joint are apt to yield, or portions of the bone adjacent to the joint are torn away. In cases of falls, when the patient alights upon the feet or ischial tuberosities, it can be understood how in many instances the main arches will escape injury owing to their great strength, while the counter-arch becomes frac- tured. Any part of the pelvis, including the sacrum, may be broken by well-localized direct violence. More or less of the iliac crest, the an- terior superior and posterior superior spines, 448 THE ABDOMEN AND THE PELVIS [Chap. have been knocked off. The first-named part may be separated as an epiphysis. It joins the bone at about the twenty-fourth year. In one case the anterior inferior spinous process was torn off by the rectus muscle during the act of running a race. The os innominatum has been broken into its three anatomical portions. This accident can- not take place after about the seventeenth year, since by that time the Y-shaped cartilage is usually fully ossified, and the three elementary bones are fully united. Before such consolidation occurs, abscess in the hip-joint not unfrequently makes its way through the cartilage into the pelvis. The acetabulum has been fractured, and the head of the femur driven through its thinnest part into the pelvis. In fractures of the pubes and ischium the bladder has been torn by the sharp fragments. In one case a loose piece of bone that had been driven into the bladder became the nucleus for a stone. The urethra and vagina also have been lacerated or seriously compressed by the displaced bones. In fractures of the sacrum the rectum has been torn, or has been so compressed by the lower fragment (which is almost always carried forwards) as to be nearly closed. Symphysis. — Separation of the bones at the symphysis without fracture has occurred from severe violence. Malgaigne reports three cases where the separation was brought about by mus- cular violence only, by extreme action of the adductor muscles of the two sides. The Sigaultean operation consisted in dividing the symphysis pubis in cases of contracted pelvis, with the idea of obtaining more room during labour, and of so avoiding Caesarian section. The union consists of fibro-cartilage and transverse peripheral fibrous bands. It varies in depth from lj to If inches, and may be divided subcutaneously, when the bones gape quite J an inch. It has been shown, however, that to gain J an inch in the antero- posterior diameter the bones must be separated to the extent of 2 inches. Such a separation involves XIX] SACRO-ILIAC SYNCHONDROSIS 449 laceration of the sacro-iliac ligaments, and more or less damage to the attachments of the pelvic viscera. The sacro-iliac synchondrosis may be the seat of disease. Normally, there is a synovial space and a slight degree of movement in this joint. As the articulation lies in the line of the great arches of the _ pelvis, it follows that, when inflamed, much pain is felt, both when the patient is standing and when sitting. When abscess forms ifc tends to come forwards, owing to the anterior ligaments being slight while the pos- terior ligament is dense, thick, and of great strength. Having reached the pelvic aspect of the joint, the pus may occupy the iliac fossa, or gain the ilio-psoas sheath. Or it may follow the lumbo- sacral cord and great sciatic nerve and point in the thigh behind the great trochanter, or it may be guided by the obturator vessels to the inner side of the thyroid foramen, and ultimately appear at the inner side of the thigh. The abscess may, however, proceed backwards, and point over the posterior aspect of the joint. The nerve relations of this joint are important. It is supplied by the superior gluteal, by the lumbo-sacral cord and the first sacral nerve, and by the first and second posterior sacral nerves (Morris). The lumbo-sacral cord and the obtura- tor nerve pass over the front of the joint, the former being very closely connected with the articulation. It will be understood from these relations that in sacro-iliac disease pain is felt over the sacral region (upper sacral nerves) and in the buttock (gluteal nerve). Much pain is also often complained of in the hip- or knee- joint, and along the inner part of the thigh (obturator nerve). In one # or two reported cases there has been severe pain in the calf and back of the thigh, with painful twitchings in the muscles of those parts (lumbo-sacral cord and connexion with the great sciatic nerve. Dislocation of the sacrum at this joint is prevented by the remark- able double wedge-shaped outline of the bone, and 450 THE ABDOMEN AND THE PELVIS [Chap. by the very dense ligaments that bind it in its place. The bone is set very obliquely, so that the weight of the body tends to force its base into the pelvis and tilt its apex upwards. The strong posterior sacro-iliac ligaments prevent the first movement, the great sacro-sciatic the second. Trendelenburg's operation, — In order to bring the two pubic bones and the deficient soft parts together in ectopia vesicae, Trendelenburg divides the sacro-iliac synchondroses on either side. The operation is limited to children between the ages of 2 and 5. The distance between the anterior superior iliac spines has, in a child aged 2j years, been lessened 2 inches by this operation. Sacro - coccygeal tumours. — The sacro- coccygeal region is very often the seat of congenital tumours, some of them of such a shape as to form u human tails "; and to this part of the pelvis has also been found attached a third lower limb leading to the condition known as "tripodism." Parasitic foetuses are also frequently found attached to this segment of the spine. In many of the instances of attached foetuses the two individuals have been joined together at this part of the column. Some of the sacro-coccygeal tumours contain epithelial cysts and fragments of skin, muscle, nerve, bone, cartilage, and mucous membrane. These strange masses spring from the anterior part of the coccyx, between it and the rectum. By some they are supposed to arise from the coccygeal body, by others (Sutton) from the structures known to embryologists as the post- anal gut and the neurenteric passage. The sacro-coccygeal joint may be dislocated or diseased. In either affection great pain is kept up from the frequent movement of the part by the muscles attached to the coccyx (the gluteus maxi- mus, coccygeus, levator ani, and sphincter). In the luxation the bone may project into the rectum, and thus give trouble. The joint and the parts about it may be the seat of such severe neuralgia ("coccygodynia") as to require excision of the XIX] PELVIC FLOOR 451 coccyx, or a free division of the structures that cover it behind. The joint and the fibrous tissue about it are supplied by the following nerves : the posterior divisions of the second, third, and fourth sacral, and the anterior and posterior divisions of the fifth sacral and coccygeal. In old age the coccyx becomes ossified to the sacrum. Floor of the pelvis and the pelvic fascia. — The outlet of the bony pelvis is occu- pied in the recent state by the following struc- tures, from behind forwards : the pyriformis, the sacro-sciatic ligaments, the coccygeus, the levator ani, and the triangular ligament of the perineum. These form the floor of the pelvis. The three structures last named serve to separate the pelvic cavity from the perineum and provide a ham- mock-like support for the viscera of the pelvis. Aperture of pelvic floor. — The pubo-rectal fibres of the right and left levator ani are separated by a narrow aperture or cleft which extends from the symphysis pubis to the ano-coccygeal body. Through it pass the anal canal, the vagina, and the urethra. In parturition it becomes greatly distended by the passage of the foetal head, and it is also relaxed and elongated during defsecation. Its length is about If inches; in defecation the fibres are relaxed and the anal canal moves back- wards and downwards so that the aperture is elongated about i an inch (R. H. Paramore). In muscular efforts, # when the musculature of the abdominal wall is also contracted, the aperture is shortened by the contraction of the pubo-rectal fibres, the anal canal being pulled towards the symphysis. The aperture is also filled, between the anal canal and the uro-genital passage, by the perineal body: the part between the adjacent borders of the aperture contains non-striated muscular tissue. Anteriorly the ( aperture is strengthened by the triangular ligament ; the mesial pubo-rectal fibres lie on this ligament. Pelvic fascia. — The pelvic fascia is a complex structure made up of the following parts : (1) 452 THE ABDOMEN AND THE PELVIS [Chap. Muscular sheaths ; (2) visceral sheaths or capsules ; (3) vascular sheaths; (4) arcuate ligament of the levator ani. The muscular sheaths are the following : (1) The obturator fascia, which covers the pelvic aspect of the obturator internus and is attached to the interior of the pelvis round the origin of the muscle; (2) the fibrous sheet on the pelvic aspect of the pyriformis, in which are embedded the internal iliac vessels and sacral nerves; (3) the sheath of the levator ani — the layer on its perineal aspect is known as the anal fascia, the stratum on its pelvic aspect as the visceral layer of fascia; (4) the triangular ligament, which is the fibrous tissue enclosing the constrictor urethrse and affording a firm attach- ment to the bulb of the penis (Elliot Smith). The visceral sheaths are : (l) the capsule of the prostate; (2) the sheath of the vagina; (3) the sheath . of the rectum. These fibrous coverings fuse with the visceral layer on the upper surface of the levator ani and with the perivascular sheaths. The perivascular sheaths are : (l) the fibrous tissue surrounding the visceral branches of the internal iliac artery — the uterine, vesical, prostatic, and hemorrhoidal — and^ round the pelvic plexus of nerves (part of this tissue has been described under the name of the suspensory ligament of the pelvic viscera — A. M. Paterson) ; (2) the fibrous sheath surrounding the internal pudic vessels, of which Alcock's canal is a^ part. The arcuate tendon of the levator ani is the structure formerly described as the white line. It is a strong band of fibrous tissue passing backwards from the posterior aspect of the pubis, near the lower border of the symphysis, to the inner aspect of the pelvis, near the ischial spine on the inner surface of the obturator fascia. From this tendinous band many fibres of the levator ani arise ; the suspensorv or perivascular ligament is also supported from it. Its middle part is often free, so that one can slip a finger down- wards between the arcuate ligament and the obtur- XIX] FIXATION OF PELVIC VISCERA 453 ator fascia ; a hernia may occur here. The muscular and vascular sheaths unite at their points of con- tact, and thus the pelvic diaphragm and viscera are welded together to form a united complex structure. Fixation and movements of the pelvic viscera. — The pelvic viscera are liable to dis- placement; a knowledge of how they are fixed and kept in position affords the only basis of a sound treatment. The bladder, rectum, and uterus must be so lodged that they may fill and empty; they must be so supported that they can withstand the violent movements and pressures to which all the abdominal viscera are subject during active muscular and respiratory efforts. To allow a free visceral movement, the parietal pelvic peritoneum is loosely attached, but over the bladder, uterus, and rectum this membrane is firmly bound down. Thus, when these viscera are distended, the reflections of the parietal peri- toneum, being attached by an extremely lax layer of subserous tissue, readily allow the viscera to expand and mount up from the pelvis. When their contents are being expelled, the visceral mus- culature requires a fixed point from which to act. The musculature of the bladder is fixed to the back of the pubis and triangular ligament by the pubo-prostatic ligament and capsule of the prostate; it is also attached to the anterior parts of the arcuate ligaments of the levator ani by the lateral true vesical ligaments. The vagina, which is also attached to the arcuate and triangular ligaments, affords an indirect attach- ment of the uterus to the pelvis during parturi- tion. The anal canal is fixed in the posterior part of the aperture of the pelvic floor. The rectum becomes continuous with the anal canal ; anterior bands^ of its longitudinal muscular coat end in the perineal body. The rectum is further fixed bv its sheath becoming continuous with the upper layer of visceral fascia on the levator ani, and to the sacrum and coccyx. This layer of visceral fascia and also the perivascular or sus- 454 THE ABDOMEN AND THE PELVIS pensory ligaments help to support the pelvic viscera in the following manner : Above, they are attached to the lateral pelvic wall by the fibrous ligament of the levator ani; below, they blend with the sheaths of the prostate, vagina, and rectum. When the viscera are in their normal position and the levatores ani are in action, these ligamentous supports are slack; it is only when the muscular support of the pelvic diaphragm is withdrawn and the viscera are displaced that these ligamentous supports come into action. In violent movements of the pelvic viscera their nerves and vessels would be subject to strain were they not protected by strong sheaths. The condition is the same as the support of the shoulder-joint : the muscles retain the bones in their normal posi- tion ; the ligaments come into action only when the limit of muscle action has been exceeded. Subserous tissue of the pelvis.— The loose subserous tissue which attaches the peritoneum to the pelvic fascia is often the seat of in- flammatory processes, especially in the female. Between the broad ligaments, round the neck of the uterus and by the sides of the vagina it is particularly abundant, and forms the perimetric and parametric tissue. It allows a free mobility to the vagina and uterus. Inflammatory processes and abscesses may spread rapidly up the sides of the pelvis and into the iliac fossae, through the subserous stratum of connective tissue. In this stratum, too, lie the ureter and the iliac vessels, surrounded by their fibrous sheaths. In this layer are also the fibro-muscular bands which form the utero-sacral and round ligaments. The utero-sacral ligaments encircle the pouch of Douglas and bind the upper part of the vagina to the loose tissue of the sacrum. The fold of peritoneum at the bottom of the recto-vesical or recto-vaginal pouch is fixed to the sheath of the prostate or vagina and to the perineal body by a septum of fibrous tissue which separates the rectum from the structures anterior to it. Nerves of the pelvis. (See p. 499.) CHAPTER XX THE PERINEUM Male perineum (Fig. 92). — This is a lozenge- shaped space bounded by the symphysis, the rami of the pubes and the ischia, the ischial tuber- osities, the great sacro-sciatic ligaments, the edges of the two great gluteal muscles, and the coccyx. A transverse line drawn across the space between the anterior extremities of the tubera ischii, and just in front of the anus, divides the perineum into two parts. The anterior part forms nearly an equilateral triangle, measuring about 3j inches on all sides. It is called the urethral triangle. The posterior part is also somewhat triangular, contains the rectum and ischio-rectal fossae, and is called the anal triangle. The whole space measures about 3j inches from side to side, and about 4 inches from before back- wards in the middle line. The average antero- posterior diameter of the pelvic outlet in the male averages 3j inches. This measurement in the un- dissected subject is increased to 4 inches by the curving of the surface. The average transverse diameter of the male pelvic outlet is 3j inches, and corresponds to the measurement of the peri- neum above given. The bony framework of the perineum can be felt more or less distinctly all round, and in thin subjects the great sacro-sciatic ligaments can be made out beneath the great gluteal muscle. The anus is in the middle line between the ischial 455 _ 456 THE ABDOMEN AND THE PELVIS [Chap, tuberosities, its centre being about if inches from the tip of the coccyx. The raphe, a central mark or ridge in the skin, can be followed from the anus Fig. 92. — The male perineum. (After Rildinger.) a, Gluteus maximus ; b, semi-tendinosus and biceps ; c, adductor magnus ; d, gracilis ; e, pyrif ormis ; /, obturator internus ; g, quad- ratus f emoris ; h, levator ani ; i, external sphincter ; j, accelerator urinae ; k, erector penis ; I, transversus perinei ; 1, great sciatic nerve ; 2, external haemorrhoidal vessels and nerve ; 3, superficial perineal vessels and nerves; 4, pudic nerve (cut) and pudic artery ; 5, pudendal branch of small sciatic nerve. along the middle line of the perineum, scrotum, and penis. No vessels cross this line, and, there- fore, in making incisions into the perineum the XX] ISCHIO-KECTAL FOSSA 457 line is always chosen when possible. In the middle line, midway between the centre of the anus and the spot where the scrotum joins the perineum, is the central point of the perineum. The two trans- verse perineal muscles, the accelerator urinse and the sphincter ani, meet at this point, which also corresponds to the centre of the inferior edge of the triangular ligament. The bulb is just in front of it, as is also the artery to the bulb, and in lithotomy, therefore, the incision should never commence in front of this spot. The perineal space is separated from the pelvic cavity by the levator ani muscles and the fascial structures connected with them. The depth oi the perineum means the distance between the skin and the pelvic floor. This depth depends, to a great extent, upon the amount of fat under the integu- ment. It varies considerably in different parts, measuring from 2 to 3 inches in the hinder and outer parts of the perineum, and less than 1 inch in the anterior parts of the space. The ischio-rectal fossa is of pyramidal shape, its apex being at the lower border of the levator ani (see Fig. 93), and its base being formed by the skin between the anus and the ischial tuberosity. The fossa is shut in at its apex by the fusion of the fibrous layers on the outer and inner wall. It becomes shallower as it passes forwards, and ceases opposite the base of t the triangular ligament. It measures about 2 inches from before back, 1 inch from side to side, and is between 2 and 3 inches in depth. Its boundaries are : on the outer side, the obturator internus muscle, covered by its fascia and the fibrous sheath of the internal pudic vessels and nerves (Fig. 93) ; on the inner side, the anal canal, covered by the anal fascia; in front, the base of the triangular ligament and the trans- versus perinei muscle; and behind, the gluteus maximus, great jsacro-sciatic ligament, and coccy- geus. The pudic vessels and nerves are placed about \\ inches above the lower border of the 458 THE ABDOMEN AND THE PELVIS [Chap. tuber ischii. ■ The fossa is occupied by a mass of fat which affords to the anal canal the support of an elastic cushion. This fatty tissue is badly supplied with blood, and this fact, in addition to the dependent situation of the part, and its exposure when the patient sits upon damp, cold seats, etc., leads to abscess being very frequent in the space (ischio= rectal abscess). These ab- scesses are hemmed in on all sides, soon fill the Long. Coat Obt. Int. Ischium Circ. Coat Anal Valves Anal Canal pudic Vessels Semitendinosus Ischio-Rectal Fossp Levator Ani Glut. Medius Fig. 93. — Section of the anal canal and of the ischio-rectal space. (Modified from figures by Prof. Elliot Smith and Sir Charles Ball ) fossa, and then tend to discharge themselves in the two directions where the resistance is least, viz. through the skin and through the wall of the anal canal. When this double discharge of the abscess has taken place, a complete fistula in ano is established. It is well to note that in fistulse in ano the opening into the anal canal is nearly always within i an inch of the anus. An opening into the bowel higher up is resisted by the union of the fibrous covering of its outer and inner wall (Fig. 93). XX] URETHRAL TRIANGLE 459 Crossing the space obliquely from its hinder part to the anus are the external hemorrhoidal vessels and nerves (Fig. 92) ; crossing the an- terior and outer corner of the fossa are the perineal vessels and nerves, and about the pos- terior border of the space are the fourth sacral nerve and some branches of the small sciatic nerve. It will be readily understood, therefore, that ischio-rectal abscesses are associated usually with extreme suffering until they are relieved. The severe pain is probably due to the rich nerve supply of the skin and mucous membrane of the anus, and also to the stretching of the external hemorrhoidal nerve by the abscess as it progresses towards the surface. In opening an abscess in the fossa the main structures to avoid are^ the rectum, the pudic and external hemorrhoidal vessels. Anus. (See p. 497.) Urethral triangle. — The skin of the peri- neum between the anus and the scrotum is thin, and shows very readily any extravasations of blood that may form beneath it. The superficial fascia is divided into two layers, of which the more superficial is quite unimportant, and con- tains what little subcutaneous fat exists in this part. The deep layer, known as the perineal fascia or fascia of Colles, is attached on either side to the rami of the pubes and ischium, and behind to the base of the triangular ligament. In front it becomes continuous with the dartos tissue. This fascia, therefore, by its attachments forms with the # triangular ligament a well-isolated aponeu- rotic space, containing the bulb with all that part of the spongy urethra between the triangular ligament and the attachment of the scrotum, the penile muscles, the transverse perineal muscles, vessels, and nerves, and the perineal vessels and nerves. When extravasation of urine follows upon a rupture of the part of the urethra above named, the course of the escaping fluid is directed 460 THE ABDOMEN AND THE PELVIS [Chap. by the fascia of Colles. It fills the aponeurotic space. It is unable to gain the ischio-rectal fossa on account of the attachment of the fascia to the triangular ligament. The lateral attachments of this membrane prevent the urine from passing into the thighs. It is therefore guided into the scrotum, and there finds itself beneath the dartos tissue. It distends the scrotal tissues, and then mounts up on to the abdomen through the gap left between the symphysis pubis and pubic spine. It must be remembered that the fascia of Colles, the dartos tissue, and the deeper layer of the superficial fascia of the abdomen are continuous, and merely represent different parts of the same structure. Pus or blood within this aponeurotic space would follow the same course if the effusion were extensive enough. The pain occasioned by such effusion can be understood when it is noted that the three chief sensory nerves of this region (the three long scrotal nerves) are included within the space. The triangular ligament has a depth of about lj inches in the middle line, and is formed of two layers, of which the posterior is thin, ill-defijied, and formed by the sheath on the lower surface of the pubic fibres of the levator ani. The membranous urethra, surrounded by the compressor urethrse, lies between the two layers, and runs about 1 inch below the symphysis, and about | of an inch above the central point of the perineum (Fig. 94). The artery to the bulb passes inwards between the two layers about J an inch above the base of the ligament and lj inches in front of the anus. The terminal part of the pudic artery pierces the anterior layer of the ligament about J an inch below the symphysis. The dorsal vein of # the penis enters the pelvis between the subpubic ligament and the apical part (transverse part) of the triangular ligament ; the dorsal nerve accompanies it (Elliot Smith). In uncomplicated rupture of the membranous urethra, the urine extravasated would be limited XX] THE PEKINEUM 461 Rectum Vesicul/e ■ Seminales .Transverse Fold Fossa Kiavicularis. Fig. 94. — Vertical antero-posterior section of the male pelvis. (Br mine.) 462 THE ABDOMEN AND THE PELVIS [Chap. to the space between the layers of the ligament, until subsequent suppuration had made a way for it to escape. When extravasation occurs be- hind the triangular ligament, the effusion may collect in the retropubic space if the capsule of the prostate is ruptured (Deanesley), or it may pass backwards by the side of the rectum into the cellular tissue of the pelvis. Just beyond the triangular ligament is the prostate, surrounded by its capsule and the pros- tatic venous plexus (Figs. 94 and 95). In dissecting down from the surface to the prostate, we meet, as Cunningham has well pointed out, alternate strata of fascial and muscular tissue, forming seven layers in all, viz. : (1) superficial fascia; (2) super- ficial perineal muscles; (3) triangular ligament (ant. layer) ; (4) compressor urethrse muscle; (5) triangular ligament (post, layer) ; (6) levator ani muscle; (7) sheath of prostate. Stone in the bladder. — Stones in the bladder, which were formerly removed by a perineal in- cision, are now commonly crushed and washed out through the urethra by the operation of litho- lapaxy. This operation is carried out readily even in male children. If the stones are too large for crushing, the suprapubic operation is performed to give sufficient room for extraction. Although the perineal operations are now but very rarely performed, a description of the parts in- volved helps to give a proper conception of their important anatomical relationships. Lateral lithotomy. — The first incision, 2 or 3 inches in length, is commenced just to the left of the middle line and just behind the central point of the perineum, t i.e. . about 1 \ inches in front of the anus. The incision is carried down- wards and outwards into the left ischio-rectal fossa, and ends at a point between the tuber ischii and posterior part of the anus, and one-third nearer to the tuberosity than to the gut. In the early part of this incision the staff may just be touched, as it lies in the membranous urethra, the XX] LATERAL LITHOTOMY 463 incision becoming more and more shallow as the knife is withdrawn. The parts cut in the first incision are: (1) skin and superficial fascia; (2) transverse perineal muscle, artery and nerve; (3) the lower edge of the anterior layer of the triangular ligament; (4) the external hemor- rhoidal vessel and nerves (Figs. 92, 93 and 94). In the second incision the knife, guided by the forefinger of the left hand, is passed upwards behind the triangular ligament, is engaged in the groove on the staff as it lies in the membranous urethra, and then, having its edge turned towards the left tuber ischii, is steadily carried along the groove into the bladder. In this incision the parts divided are : (1) membranous and prostatic portions of urethra; (2) posterior layer of tri- angular ligament ; (3) compressor urethrse ; (4) anterior fibres of levator ani and left lateral lobe of prostate. The finger is then introduced along the staff into the bladder, the staff is removed, and, the forceps being inserted, the stone is ex- tracted, traction being made in the proper axis of the pelvis. Parts that may be wounded. — (a) In the first incision : (1) the bulb, or the artery of the bulb. These parts can be avoided by commencing the incision well behind the " central point/' and by causing the holder of the staff to draw it, the scrotum, and the penis well up. The staff should be held as close up under the pubes as possible. The bulb is very small in children, large in adults, and largest in old men. (2) The rectum may be cut if much distended, or if the incision be made too vertical or carried too far back. In all cases the gut should be well emptied by enema before the operation. (3) The pudic vessels can hardly be wounded unless the incision is very carelessly made, and the knife carried almost against the bone as it is being withdrawn, (b) In the second incision the knife may be passed beyond the prostate, and may so incise the vis- ceral layer of the pelvic fascia as to open up the 464 THE ABDOMEN AND THE PELVIS [Chap. pelvic cavity. It will be understood that the lateral lobe of the prostate may be cut freely without this cavity being endangered. The gland is enveloped by the pelvic fascia, but the incision made into the prostate is well below the superior reflection of the membrane. The incision in the neck of the bladder, therefore, must be strictly limited to the prostate. The prostatic plexus of veins cannot avoid being wounded. The left ejaculatory duct would be cut if the prostatic incision were carried too far backwards. In children the pelvis is relatively narrower than in the adult, the bladder is more an ab- dominal than a pelvic organ, and the neck of the bladder, therefore, is high up. The viscus, more- over, is very movable, and has less substantial attachments than has the adult's bladder. It thus happens that, in forcing the finger into the bladder after the second incision, the viscus has actually been torn away from the urethra. In children the prostate is rudimentary, and thus more of the actual neck of the bladder itself has to be cut. From the small size of this gland, it hap- pens, too, that in some cases the knife has passed too far beyond the prostatic area, and has opened up the pelvic fascia. In children also the peri- toneum descends lower on the posterior surface of the bladder, and may be wounded by a careless operator. Median lithotomy.— In this^ operation the knife is entered in the middle line, just in front of the anus. The staff has a central groove, and the point of the knife should hit the instrument as near as possible to the apex of the prostate. As the knife is withdrawn the whole of the mem- branous urethra is incised, and: a wound made in the median raphe of about lj inches in length. Parts divided, — (1) Skin and superficial fascia ; (2) sphincter ani ; (3) central point of perineum; (4) lower border of triangular liga- ment; (5) whole length of membranous urethra; (G) compressor urethrse. XX] LITHOTOMY 465 In lithotomy, and in other operations for reach- ing the neck of the bladder through the perineum, it should be remembered that the bladder lies at a depth of from 2j to 3 inches from the surface when the body is in the lithotomy position (Fig. 94). If the bladder is empty and the rectum full, the prostate, trigone and reflection of peritoneum are carried upwards and forwards; if the bladder is full and the rectum empty, the movement is in an opposite direction. In fat people the bladder and peritoneum are carried away from the perineum; in lean people the opposite occurs. Suprapubic lithotomy. — This operation has been revived of late years, and in cases in which litholapaxy is contra-indicated has practically supplanted the two forms of lithotomy just de- scribed. In order to bring the summit of the bladder well above the symphysis, both bladder and rectum may be dilated. Into the former vis- cus, tepid water or boric lotion is injected. It is found that in the adult 8 to 10 ounces is suffi- cient to ensure the desired distension. The rec- tum is dilated by some operators by means of a soft rubber bag. The gut, when thus distended, pushes forward the bladder, and gives it a firm basis upon which to rest. In the adult from 10 to 14 ounces is usually introduced into the bag. In the case of a male child, aged 5, the injection of 3 ounces of water into the bladder caused the reflection of peritoneum to mount to more than 1 inch above the symphysis. An incision, some 3 inches in length, is made immediately above the symphysis in the median line. The bladder is exposed below the peritoneum, is drawn forwards by a hook, and opened. The bladder. — When empty the bladder is flattened and of triangular outline, and lies against the anterior wall of the pelvis. The empty bladder may be found in one of two condi- tions (as demonstrated by Dr. Hart in the adult female bladder). It may be small, oval, and firm, with its upper wall convex towards the 466 THE ABDOMEN AND THE PELVIS [Chap. abdomen. In vertical anteroposterior section the urethra forms with the cavity of the bladder a curved slit (the systolic empty bladder). It may be larger, and soft, with its upper surface con- cave towards the abdomen, and fitting into the concavity of the lower wall or surface. In the section named, the urethra forms, with the blad- der cavity, a Y-shaped figure, the two diverging limbs of the Y corresponding to the concavity named (the diastolic empty bladder). When moderately distended with an opaque solution and examined by the aid of X-rays it is seen to be conical in form, with its apex behind the sym- physis and its base or upper surface indented by the pressure of the abdominal viscera (Fig. 91, p. 439). As distension of the bladder increases, the summit of the viscus is brought more and more in contact with the anterior abdominal wall, the organ becoming also more convex on its posterior than on its anterior surface. This tendency for the summit of the distended bladder to press itself against the anterior parietes is of good service in tapping the organ above the pubes, and in supra- pubic lithotomy. When greatly distended it may reach the umbilicus, and may even touch the diaphragm. The usual capacity of the organ is about one pint, but when quite full it may hold some quarts. When both bladder and rec- tum are quite empty the apex of the bladder and the prevesical reflection of the peritoneum are a little below the upper margin of the symphysis pubis. As the distended bladder ascends above the pubes it dissects the serous membrane from the parietes, and the layer so lifted off forms a cul-de-sac or fold of peritoneum between the upper part of the anterior surface of the bladder and the parietes. When the apex of the bladder is 2 inches above the pubes the peritoneal reflection is probably not more than | of an inch above the same point of bone. When the apex of the bladder is midway between the umbilicus and the pubes there may be 2 inches (vertical) of the XX] THE BLADDER 467 anterior abdominal wall in the middle line and immediately above the symphysis devoid of peri- toneal lining. Thus it happens that the distended viscus may be readily tapped above the pubes without the peritoneum being wounded. As the bladder becomes distended, not only does it rise into the abdomen, but it extends also towards the perineum, diminishing the length of the prostatic and membranous urethra. Between the anterior surface of the bladder and the symphysis, and shut in by the peritoneum above, is the retropubic or prevesical space, con- taining lax connective tissue (Fig. 95). The loose- ness of this connective tissue permits the bladder readily to ascend as it fills. In injuries to the pelvis and to the front of the bladder a diffuse inflammation may be set up in this tissue and assume serious proportions. I have^ reported a case where an extensive suppuration in this area followed upon aspiration of the bladder above the pubes, and led to death. Like suppuration has followed suprapubic lithotomy. Extension of the abscess into the perineum is limited by the fascial reflections formed by the pubo-prostatic and lateral vesical ligaments. The bladder, although fairly fixed, has been found in inguinal, femoral, and vaginal hernise. In the erect position its neck (in the male) lies on a horizontal line drawn from before backwards through a point a little below the middle of the symphysis, and is placed about l\ inches (3 cm.) behind that articulation (Tillaux). Relations of the bladder to the peritoneum. — The anterior surface is entirely devoid of peritoneum, while the superior surface is entirely covered by that membrane. At the sides there is no peritoneum in front of, or below, the obliterated hypogastric arteries. On the posterior aspect of the bladder the serous membrane extends down as far as a transverse line uniting the upper parts of the two seminal vesicles, so that the upper ends of the vesicles are covered by peritoneum. This 468 THE ABDOMEN AND THE PELVIS [Chap. recto-vesical pouch of peritoneum in the adult ex- tends to within about 3 inches of the anus, and does not reach below a line 1 inch above the base of the prostate. Harrison Cripps gives the dis- tance of the pouch from the anus as 2j inches when the bladder and rectum are both empty, and as 3i inches when those viscera are distended. (See Bladder in the Child, p. 472.) Puncture of the bladder per rectum. — The base of the bladder is applied to the lower part of the rectum, but they are separated by a thin fibrous septum — the recto-vesical. The area in contact with . the rectum is triangular in shape, the apex being formed ^ by the ^ prostate, the sides by the diverging seminal vesicles, and the base by the recto-vesical fold of peritoneum. This triangle is equilateral, and in the dissected specimen measures about lj inches on all sides. It corresponds to the trigone on the inner surface of the viscus. It is through this triangle, and as near as possible to the prostate, that the blad- der is tapped when the operation is performed per rectum. The recto-vesical fold of peritoneum is raised, and is carried still farther from the anus when the organ is distended. Rupture of bladder.— The bladder may be ruptured by violence applied to the anterior abdominal wall apart from pelvic fracture or external evidence of injury. Such a rupture can, however, hardly happen to the empty bladder; it must be full or distended at the time of the acci- dent. ^ It is very rare for the rupture to be on the anterior surface only. As a rule, the tear in- volves the superior or abdominal surface, and implicates the peritoneum. The injury, therefore, is very fatal (5 recoveries out of 78 cases). In some cases of vesical rupture the surgeon has opened the abdomen and has stitched up the rent in the viscus with perfect success. The bladder may be torn by fragments of bone in fractures of the pelvis, or by violence applied through the rectum or vagina. A case, for ex- XX] RUPTURE OF BLADDER 469 ample, is reported (Holmes's " System of Sur- gery ;; ) of a man who fell upon a pointed stake fixed in the earth. The stake passed through the anus, pierced the rectum, and entered the bladder near the prostate. The patient recovered, the wound having been made in the triangular area on the fundus of the bladder alluded to above, and therefore outside the peritoneum. The viscus may be ruptured by an accumulation of urine, as seen in cases of congenital closure of the urethra in some infants. In the museum of the Royal College of Surgeons is a preparation of " the bladder of a woman which burst near the entrance of the ureter in consequence of neglected reten- tion of urine. " In neglected cases of stricture in the male the urethra gives way rather than the bladder, and an extravasation of urine into the perineum follows. A small puncture of the bladder, as, for example, that made by a fine trocar, is at once closed by the muscular con- traction of its wall. The mucous membrane of the bladder is very lax, to allow of its accommodating itself to the varying changes in the size of the viscus. Over the trigone, however, it is closely adherent, and were it not so the loose mucous membrane would be constantly so prolapsed into the urethral orifice during micturition as to block up the neck of the bladder. When examined by the cystoscope, the mucous membrane is seen to be red and con- gested when the bladder is empty, pale and anaemic when the bladder is full (Newman). The trigone is bounded by three orifices, for the ure- thra and the two ureters, and forms an equilateral triangle, measuring about lj inches on all sides. It is here that the effects of cystitis are most evi- dent, and the unyielding character of the mucous membrane over the trigone serves in part to ex- plain the severe symptoms that follow acute in- flammation of that structure. Since the orifice of the urethra forms the lowest part of the bladder in the erect posture, it follows that calculi gravi- 470 THE ABDOMEN AND THE PELVIS [Chap. tate towards the trigone^ and are very apt to irritate that part of the interior. The same re- mark applies to foreign bodies in the viscus. The mucous membrane about the trigone and neck is very sensitive, whereas the interior of the re- mainder of the bladder appears to be singularly defective in common sensation. This can be well noted in using sounds and catheters. The sensory nerves for the bladder are de- rived mainly from two parts of the spinal cord, namely, the twelfth dorsal and first lumbar seg- ments, and the second, third, and fourth sacral segments. t From the first source (through the hypogastric plexus) come the sensory nerves to the upper part of the bladder and the motor nerves which stimulate the internal sphincter and inhibit the expelling musculature; from the second source (through the nervi erigentes) the motor fibres which stimulate the expelling^ mus- culature and inhibit the sphincter. The trigone, having the same nerve supply as the j)enis and scrotum, gives rise, when injured, to pains which are referred along the perineal nerves. In the muscular coat of the bladder the^ fibres are collected in bundles^ which interlace in all directions. When the viscus becomes hypertro- phied these bundles are rendered very distinct, and produce the appearance known as "fascicu- lated bladder. " This simply means that the muscle of the bladder, having been unduly exer- cised to overcome some obstruction to the escape of urine, increases in size, as do other much- exercised muscles, and that increase # serves to demonstrate the arrangement of the individual bundles. From distension the mucous membrane becomes bulged out between the unyielding muscle bundles, so that sacculi are formed, and the ap- pearance known as " sacculated bladder " is pro- duced. In some cases the parietes yield, especially at one part, and one large saccule is produced. In this way a sacculus may be formed which in time may become almost as large as the bladder XX] THE URETER 471 itself, and give rise to the erroneous description of " double bladder/' etc. The ureters run for f of an inch in the mus- cular wall of the viscus, and their oblique course, together with the action of the neighbouring vesical musculature, prevents the regurgitation of urine from the bladder. No circular muscular fibres surround the termination of the ureter ; there is nothing of the nature of a sphincter to safeguard the orifice (T. B. C. Benians). On cystoscopic examination it is seen that once or twice a minute each ureter contracts and expels a spurt of urine into the bladder; between these spurts the ureteric orifices are closed by the intra- vesical pressure. If the ureter becomes shortened, as is the case if it is the seat of a tubercular ulceration, the vesical orifice of the ureter is drawn outwards (Fenwick). The mucous mem- brane is laxly attached and may be prolapsed within the bladder as a pedunculated body. In cases of retention the ureters become distended ; but this is due rather to accumulation of urine within them than to its reflux from the bladder. In cases of great distension of the bladder the neck of the viscus is opened up by the pressure from within, and the patient exhibits the feature of overflow of urine. A band of muscle passes from the sheath of the ureter towards the in- ternal urinary meatus along each side of ^ the trigone (Bell's muscle), while another (Mercier's bar) unites the orifices across the base. These bands maintain the ureteral orifices in position when the bladder is full, and safeguard their valvular mechanism (Wright and Benians). The female bladder is less capacious than that of the male. Its neck is situated a trifle nearer to the symphysis than it is in the male, and lies in a horizontal line continued back from the lower border of the symphysis. There being no prostate, the neck of the bladder is very dis- tensible, and this fact, taken in connexion with the shortness and dilatability of the urethra, 472 THE ABDOMEN AND THE PELVIS [Chap. allows of most stones being extracted by forceps without cutting. By simple dilatation, stones of a diameter of f of an inch have been removed. Through the dilated urethra the orifices of the ureters can be seen and examined. The intimate relation of the bladder to the vagina allows it to be examined well from the latter passage, and the comparative thinness of the dividing wall serves to explain the frequency of vesico-vaginal nstulse.^ Strange foreign bodies have been intro- duced into the female bladder, such as hair-pins, crochet-hooks, sealing-wax, penholders, and the like. The orifice of the ureter is 3 cm. from the cervix uteri, and 4 cm. from the vesical opening of the urethra. Its close relation to the cervix renders it liable to injury in supravaginal amputation of that part, and in certain operations on the uterus. The bladder in the child is egg-shaped, and its vertical axis is relatively much greater than it is in the adult. The larger end of the egg- shaped cavity is directed downwards and back- wards. The fundus is developed and the pelvic position assumed about the fourth year (Birming- ham). The viscus is situated mainly in the abdo- men, the pelvis being small and very shallow. At birth the orifice of the urethra is on a level with the upper edge of the symphysis. Although the bladder projects so freely into the abdomen, its anterior wall is still entirely uncovered by peri- toneum. On the posterior wall the serous mem- brane extends lower down than in the adult, reaching the level of the urethral orifice at the time of birth, and the level of the prostate in young male children. The prostate is exceedingly small in children. Thompson states that at the age of 7 years it only weighs 30 grains, whereas in subjects between 18 and 20 weighs 250 grains. The bladder wall in the child is so thin that in sounding for stone it is said that a "click" may be elicited by striking the pelvis through the parietes of the viscus. XX] PEOSTATE GLAND 473 The prostate. — The prostate is situated about | of an inch below the symphysis pubis, and rests upon the rectum above the anal canal (Fig. 94). It is, therefore, placed within 1^ to 2 inches from the anus, and can be readily examined from the bowel. The prostate is made up of two lateral lobes which fuse together in front of the urethra by a pubic commissure (Fig. 95) and behind by Fig. 95. — 1, Median section of the normal prostate ; 2, similar section of enlarged prostate. A, A, Sphincter vesicae ; B, median commissure ; C, common ej a di- latory duct ; D, rectal commissure ; E, E, constrictor urethrse ; F, recto-urethral muscle ; G, Cowper's gland ; H, ejaculator urinae ; I, internal sphincter of anus ; J, external sphincter of anus ; K, symphysis pubis ; L, retropubic space ; M, pubo-prostatic liga- ments and sheath of prostate ; N, dorsal vein of penis ; o, pubic commissure ; P, corpus cavernosum ; Q, urethra : R, bulb. two commissures, one above the common ejacula- tory ducts — the median commissure — and one be- low these ducts — the rectal commissure {see Fig. 95, b, d). The part here named median commis- sure was formerly known as the median lobe — a name which is apt to mislead, for it is not a separate lobe, but, as already explained, merely | a fusion of the two lateral lobes. Each gland is made up of numerous branching tubular glands 474 THE ABDOMEN AND THE PELVIS [Chap. which are embedded in and surrounded by non- striated muscle and fibrous tissue. The glands end in the urethra — chiefly in the prostatic sinuses — but the use of their secretion is un- known. The secretion from the gland is discharged through the long and very narrow ducts of glands which are diffusely arranged as two lateral masses or lobes. In certain forms of prostatic irrita- tion, little white opaque threads, very much like short pieces of cotton, are found in the urine, and are actual casts of the prostatic ducts. Capsule of the prostate. — Owing to the suc- cess which has attended enucleation as a means of treatment for enlarged prostate, much dis- cussion has recently taken place concerning its ensheathing structures. The term capsule has been proposed for the superficial fibro-muscular stratum of the gland, while the term sheath has been applied to the enveloping fibrous struc- ture derived from the pelvic fascia. In enu- cleating the gland everything within the sheath is removed. At only one part is the sheath in- timately adherent to the capsule, and that is along the anterior or pubic surface; elsewhere it is free from it. Since the base of the prostate is applied to the bladder and uncovered by the sheath, while elsewhere it is enclosed, it follows that the sheath is most easily entered and the gland enucleated from the bladder. The sheath determines the course of a prostatic abscess. p The apex of the prostate rests on the constrictor urethrae ; its sides are applied to the pubo-rectal fibres of the levator ani ; hence the capsule of the prostate fuses with the adjacent sheaths of these two muscles. The prostatic plexus of veins, which receives the vesical veins, tributaries and communications of the dorsal vein of the penis, internal pudic and obturator veins, lies in the fibrous tissue between the prostate and levator ani. The tissue to the outer side of the veins is counted capsule ; that to the inner, sheath. The XX] PROSTATIC HYPERTROPHY 475 capsule of the prostate behind is formed by the recto-vesical septum. The prostatic abscess usually bursts into the urethra, that being the direction in which least resistance is encountered. If it does not enter the urethra, it will probably open into the rectum, there being only one layer of the pelvic fascia, and that layer not a thick one, between the two organs. This encasement of the gland in an unyielding membrane will serve, in part, to explain the severe pain felt in acute prostatic abscess. In acute prostatitis pains are referred over the tip of the last rib (10th dorsal nerve), over the posterior iliac spine (11th dorsal nerve), or even to the soles of the feet (3rd sacral nerve). The prostate derives its nerve supply from the lower three dorsal and upper three sacral segments; hence the widely distributed character of the referred pains (Head). Hypertrophy of the prostate. — The average measurements of the normal prostate are 1\ inches across at its widest part, and 1\ inches from before backwards, or from apex to base. After the age of 53 the organ is very apt to become hypertrophied ; and, according to Sir Henry Thompson, this hypertrophy may be considered to exist when the gland measures 2 inches from side to side, or when it weighs 1 ounce or more. The usual weight of the prostate is 6 drachms. If the enlargement mainly affect the lateral parts, it will be understood that the hypertrophy may attain considerable dimensions without retention of urine being produced. On the other hand, a comparatively trifling enlargement of the median commissure may almost entirely block the orifice of the urethra. As this part enlarges it pushes its way into the bladder through the urethral orifice, dilating and destroying the sphincter vesicae and forming a mechanical obstruction to the free passage of urine (Fig. 95, 2). If the affection be general, the prostatic urethra is lengthened, and if one lateral lobe be more en- 476 THE ABDOMEN AND THE PELVIS [Chap. larged than the other, the canal deviates to one side. When the enlargement particularly affects the median commissure, the prostatic urethra, which is normally almost straight, becomes con- siderably curved, the curve being sometimes very abrupt. It is important to note that enlarge- ment of the median commissure alone can hardly be made out by rectal examination. The project- ing middle commissure, when viewed from the in- terior of the bladder, may appear as a distinct, well-rounded, pedunculated or sessile growth. In the operation of prostatectomy this pro- jecting and most troublesome mass is removed through a suprapubic incision. Everything within the sheath of the prostate — gland, urethra, common ejaculatory ducts — is enucleated by the surgeon's finger through the base of the bladder ; the sheath then encloses a space which at first is filled with blood and urine, but afterwards con- tracts to form a new urethra. The prostate is a sexual organ, and its size and development de- pend on the presence and activity of the testes. Castration prevents its development or causes atrophy if already developed. Removal of one testicle causes a partial atrophy, but section of the vasa deferentia has usually no effect (C. Wallace). The lymphatics of the prostate, which are numerous, pass to a group of glands on the wall of the pelvis, between the external and internal iliac arteries. The male urethra is about 8£ inches in length (21 cm.), \\ inches being devoted to the prostatic urethra, f of an inch to the mem- branous, and 6j inches to the penile or spongy portion. Between the ages of 4 and 6 years its length is 8 to 9 cm., and between 10 and 13 years 10 to 11 cm. The canal may be divided into a fixed and a movable part. The fixed part extends from the neck of the bladder to the posterior extremity of the penile urethra at the point of attachment of the suspensory ligament. This fixed part describes an even curve, fairly XX] MALE URETHRA 477 represented by the line of a " short curve " metal catheter. The two ends of the curve lie about in the same line, viz. one drawn across the lower end of the symphysis, and at right angles to the vertical axis of that articulation. The curve is formed around this line, its centre summit corre- sponding to a prolongation of the vertical axis of the symphysis, and to about the centre of the mem- branous urethra. This part of the tube lies about 1 inch below the pubic arch. The movable portion of the urethra forms, when the penis is dependent, a second curve in the opposite direction, so that the whole canal follows somewhat the outline of the letter S. The prostatic portion of the urethra is nearly vertical. < It is surrounded by circular muscular fibres which may give rise to a spasmodic stricture (.Fig. 95). The sinus pocularis or uterus mascu- linus, in the floor of this part of the urethra, represents the united ends of the rudimentary Miillerian ducts. The penile or spongy portion of the urethra is surrounded by the erectile tissue of the corpus spongiosum urethras, which is thickest on the under side of the canal. A very thin layer of erectile tissue surrounds the membranous urethra lying beneath the fibres of the compressor urethrae. In introducing a catheter it must be noted that while the instrument passes along the mov- able urethra, the canal accommodates itself to the catheter, but while traversing the fixed segment the instrument must accommodate itself to the unyielding canal. In introducing a catheter in the recumbent posture the penis is held vertically upwards, and in this way the curve formed by the movable urethra is obliterated. The instru- ment is best kept close to the surface of the groin, and over and parallel to Poupart's ligament. When the fixed urethra is reached, the handle of the catheter is brought to the middle line, and then, being kept strictly in the median plane of 478 THE ABDOMEN AND THE PELVIS [Chap the body, is depressed between the legs, so that the front of the instrument may follow the natural curve of the canal. The greatest difficulty in the introduction is generally experienced at the point where the movable and fixed parts of the urethra meet; or, rather, in practice, at a spot a little behind this point, viz. at the anterior layer of the triangular ligament (Fig. 95). At this spot the tube abruptly becomes not only very fixed, but also very narrow, and a part of it is reached where muscular tissue is very abundant, and where resistance from muscular spasm is there- fore likely to be most marked. It thus happens that when a false passage has been made by a catheter in a case where no stricture exists to offer a definite obstruction, the instrument is usually found to have left the canal just in front of the triangular ligament. Some other points in connexion with cathe- terization will be noted subsequently. The urethral canal must not be regarded as forming an open tube like a gas-pipe. Except when urine or an instrument is passing along it, the tube appears on section as a transverse slit, the superior and inferior walls being in contact. This fact should be remembered in amputation of the penis by the ecraseur. In the fossa navicu- lars the tube appears as a vertical slit. The prostatic part of the canal is the widest and most dilatable portion of the whole urethra. It is widest at its centre, having here a diameter of nearly \ an inch; at the bladder end its dia- meter is about \ of an inch, while at the anterior extremity of this part of the urethra the measure- ment is a little less than J of an inch. When small catheters are being introduced their points may lodge in the orifice of the utricle, unless the tip of the instrument be kept well along the roof of the canal. The ejaculatory^ ducts open into the prostatic urethra, and thus it happens that in- flammation of this part of the canal may spread back along those ducts to the seminal vesicles, and XXJ THE UEETHEA 479 from thence along the vas deferens to the epi- didymis (Fig. 95). It is by spreading along these parts that inflammation of the testicle is set up in gonorrhoea involving the prostatic urethra, and it will be understood that a like inflam- mation may follow lateral lithotomy, impacted stone in the prostatic urethra, prostatic abscess, and the like. Stricture never occurs in this part. The membranous urethra is, with the exception of the meatus, the narrowest part of the entire tube. Its diameter is about \ of an inch. It is fixed between the two layers of the triangular ligament, and is the most muscular part of the canal. It is at this spot, therefore, that what is known as "spasmodic stricture " usually occurs. In any case, the contraction of the constrictor urethrae often offers an appreciable amount of resistance to the passage of a catheter or sound (Fig. 95). The penile urethra is dilated at either end, viz. at the parts occupying the bulb and the glans penis respectively. The diameter of the bulbous urethra is midway between that of the prostatic and membranous segments of the canal, while that of the greater part of the penile urethra is mid- way between that of the bulbous and membran- ous portions. It is in the bulbous urethra that organic stricture is the most commonly met with. The meatus measures from \ to \ of an inch, and therefore if a catheter will pass the meatus it will pass along any part of the normal canal. Its aperture is very resisting, and has often to be incised to allow the larger instruments to pass. The narrowest parts of the urethra, therefore, are (1) at the meatus, and (2) in the membranous segment, especially at its anterior end. It is at these points that calculi passed from the blad- der are most apt to lodge. The widest portions of the canal, on the other hand, are at (1) the fossa navicularis, (2) the bulbous part of the 480 THE ABDOMEN AND THE PELVIS [Chap, urethra, and (3) the centre of the prostatic portion. The mucous membrane of the urethra pre- sents, in addition to many mucous glands, several lacunae, the orifices of which for the most part open towards the meatus. These lacunae are most numerous in the bulbous urethra, and occupy the floor rather than the roof of the canal. In passing small catheters, therefore, the point of the instrument should be kept along the upper surface of the tube, so that it may not become engaged in any of these spaces. The largest lacuna, the lacuna magna, is situate in the roof of the fossa navicularis, and may readily engage the point of a small instrument. The urethra may be ruptured by the patient falling astride of some hard substance. In such an injury it is crushed between the hard substance and the pubic arch. The part of the canal, there- fore, that is most often damaged is the mem- branous segment, and the posterior part of the penile division. The more the body is bent for- wards at the time the perineum is struck, the greater is the length of penile urethra that may be crushed against the pubes. The female urethra is about \\ inches in length, and has a diameter of from i to J of an inch. It is capable, however, of great distension. In the erect position the canal is nearly vertical, and in the recumbent posture almost horizontal. The penis. — The skin covering the bulk of the organ is thin and fine, and the subcutaneous tissue is scanty and lax. It follows, from the looseness of this tissue, that the skin is very distensible and movable^ The latter fact should be borne in mind in circumcision, for in performing that operation the skin of the penis can be so readily drawn forwards over and beyond the glans, that if it is excised as far back as possible the greater part of the organ may be left bare. This applies, of course, mainly to children. The laxity of the submucous tissue permits the organ to be- : XX] THE PENIS 481 come enormously swollen when cedematous, or when extravasated urine finds its way into the part. Over the glans penis the mucous mem- brane is so adherent that there is practically no subcutaneous tissue. It happens, therefore, that when Hunterian chancres appear on this part they can never be associated with other than the most trifling induration, there being no tissue in which the thickening can develop. At the corona, on the other hand, the submucous tissue is lax and plentiful, so that the induration can readily form, and it is about this spot, therefore, that the syphilitic sore often attains its most characteristic Prepuce Corp.Cavermosum Clams. LACUNA AlAQ/iA- (f& P05SA /1AVICULARI5 PERMANENT MCATl Primitive AIbatus Fig. 96. — Section of a penis, showing a common form of hypospadias. The cross marks the point where the tissue breaks down between the cloacal urethra and meatal ingrowth. development. The vascularity of the penis, and the rapid engorgement that ensues when the re- turn of its venous blood is impeded, serve to ex- plain the ready and extensive swelling of the organ that follows when any constricting band is placed about it. This should be borne in mind in tying in a catheter by securing it by tapes around the penis. The blood spaces in the corpus spongi- osum may be rendered indistensible from gonor- rhceal inflammation while those of the corpora cavernosa remain free. The corpus spongiosum then acts like the string of a bow during the erec- tion of the penis. Through the superficial lym- phatics disease may spread from the skin and meatal region of the penis to the inner of the Q 482 THE ABDOMEN AND THE PELVIS [Chap. inguinal glands. Deeper vessels pass with the prostatic veins to the internal iliac group of glands on the lateral wall of the pelvis. Some vessels pass directly to the external iliac glands through the crural ring. The penis is frequently the seat of arrests of development, presenting a variety of appearances. Among them may be men- tioned hypospadias, where the inferior wall of the urethra and corresponding part of the corpus spongiosum are wanting, and epispadias, where the superior wall of the canal and corresponding parts of the corpora cavernosa are more or less entirely deficient. In the condition of hypo- spadias two meati are present — one situated on the glans opening into a cul-de-sac which repre- sents the fossa^ navicularis, and another just behind leading into the urethra (Fig. 96). Here is seen the double origin of the male urethra — the part within the glans is formed by an ingrowth of epithelium from the surface of the glans, while the rest of the penile urethra is derived from the cloaca. i At first the cloacal urethra opens by its own orifice (primitive meatus, Fig. 96), but in the course of development the ingrowth from the glans takes place to form the permanent meatus and fossa navicularis; when this ingrowth opens into the cloacal urethra the primitive meatus becomes closed. The frenum preputii is formed over it. The condition thus represented is one of ar- rested development. On the prepuce of such cases sebaceous glands are arranged in two pigmented oval groups — preputial ocelli (Shillitoe). The scrotum.— The skin of the scrotum is thin and transparent, so that in bruising of the parts the discoloration due to the extravasation of blood beneath the surface is readily and distinctly seen. It is alsovery elastic, and allows of great distension, as is seen in large scrotal hernise and testicular tumours. The integument of the part is indeed # redundant, and the excision of a portion of it will hardly be missed. Even in gangrene of the scrotum, when both testicles XX] THE SCROTUM 483 have been exposed, the parts have been entirely restored without any inconvenient shrinking or contraction. The rugce on the surface of the scro- tum favour the accumulation of dirt, and the irritation set up by such accumulation may be the exciting cause of the epitheliomata that are not uncommon in this part. When the surface is sweating, the rugse tend to favour a retention of the moisture between their folds; from this and other circumstances it happens that the scrotum is liable to eczema and to those syphilitic skin disorders that are often localized by irritation. The rugse are a sign of health, since they depend upon the vigorous contraction of the muscle fibres in the dartos tissue. In the enfeebled, or under • the relaxing effects of heat, the scrotum becomes smooth and pendulous. In a simple incised wound, as in castration, the dartos is apt to turn in the edges of the skin and cause some difficulty in applying the sutures. This difficulty may be avoided by relaxing that tissue for a while by the application of a warm sponge to the wound. The subcutaneous tissue is lax and very ex- tensive, and permits of considerable extravasa- tions of blood forming beneath the surface. It is unadvisable, therefore, to apply leeches to the scrotum itself, since they may lead to an unde- sirable outpouring of blood beneath the skin, and to the appearance of a considerable ecchymosis. Leeches in testicular affections had better be ap- plied over the region of the cord. The scrotum, from its dependent position, and from the looseness and extent of its cellular tissue, is often the first part of the body to become cedematous in dropsy, and is apt to show that cedema in a marked degree. The scrotum also is the part most frequently the seat of elephantiasis, which is due essentially to a distension of the lymphatic vessels and spaces of the connective tissue. The vitalitv of the scrotum is not consider- able, and it therefore not infrequently sloughs in parts when severely inflamed. For this reason 484 THE ABDOMEN AND THE PELVIS [Chap. strapping should be applied with some care over the enlarged testis, for against the hard mass of the affected gland the integument of the scrotum can be subjected to considerable pressure when the strapping is tightly applied. In such a case I have seen the whole of one side of the scrotum slough from an indiscreet use of this familiar method of treatment. The testicle may be retained within the ab- dominal cavity, or may lodge for varying periods of time, or for life, in the inguinal canal. It may, on the other hand, pass beyond the scrotum into the perineum, or may miss the inguinal canal altogether and escape through the femoral canal and saphenous opening on to the thigh. t The testis proper is entirely invested by the visceral layer of the tunica vaginalis, except over a small part of its posterior border where the vessels enter. The epididymis is entirely covered by the serous membrane at its sides, is more or less so covered in front, but is free or uncovered along the greater part of its posterior border (see Fig. 74, p. 356). ^ It is about the posterior border of the epididymis that the visceral layer of the tunica vaginalis joins the parietal layer. The posterior border of the testicle and of the epi- didymis — from globus major to globus minor — is bound by a reflection of serous membrane — the mesentery of the testicle. Instead of binding the whole of the posterior border, the mesentery may be attached merely ^ to the lower pole of the testicle and globus minor ; on such a pedunculated attachment the testicle is apt to become stran- gulated by a twisting of its narrow mesentery. A narrow^ elongated mesentery is found only in glands which are late in descending or have been arrested in their descent ; torsion of the testicle is, therefore, only possible in imperfectly de- veloped organs. The more intimate and exten- sive connexion of the serous tunic with the testis or gland proper serves in part to explain the greater frequency with which hydrocele appears XX] THE TESTICLE 485 in inflammation of this part of the organ, as compared with its occurrence when the epididy- mis is alone inflamed. It is owing to the reflec- tions of the tunica vaginalis that in cases of common hydrocele the testicle remains firmly set at the lower and posterior part of the swelling, and yet so extensively is the organ surrounded by that membrane that the position of the gland in the larger hydroceles is often difficult to deter- mine. In some cases the testicle occupies the front of the scrotum, the epididymis being placed an- teriorly, and the body of the gland being located behind it. The vas deferens descends also along the front of the cord. In these cases the testicle is just in the position it would occupy if it had been turned round upon its vertical axis. The condition is known as inversion of the testicle, and should be sought for in cases of hydrocele, as in several instances the testis has been pierced by the trocar when tapping collections in cases where the inversion existed. The proper gland tissue is invested by a very dense membrane, the tunica albuginea. The epi- didymis, on the other hand, lacks any such firm fibrous investment. The unyielding character of the tunica albuginea serves in great part to ex- plain the intense pain felt in acute affections of the testis proper, a degree of pain which is not reached when the less tightly girt epididymis is alone involved. It will be understood also that in inflammation of the epididymis the part swells rapidly and extensively, while in a like affection of the body of the gland the swelling is compara- tively slow to appear. It should be borne in mind that the lymphatics of the scrotum go to the inguinal glands, those of the testicleto the lumbar; in malignant disease of the testicle the secondary deposits are to be expected deep within the abdomen by the side of the aorta. The testicle is developed in front of the 10th dorsal vertebra, and receives its nerve supply from the 10th dorsal segment. Its nerves 486 THE ABDOMEN AND THE PELVIS TChap. pass by the small splanchnics, solar and aortic plexuses, to the spermatic artery, on which they reach the gland. The epididymis receives its nerve supply from the pelvic plexus, along the vas deferens. Spermatic cord, — The structures in the cord are (1) the vas deferens, (2) the cremaster muscle, (3) the spermatic and (4) cremasteric arteries, (5) the artery to the vas deferens, (6) the pampiniform plexus of veins, (7) the genito-crural nerve, (8) sympathetic nerve fibres, -S.A Fig. 97.— Section of the left spermatic cord of an adult, at the level of the external abdominal ring, viewed from above. {From a specimen prepared by Mr. W. G. Spencer.) VD, vas deferens ; DA, deferential artery ; DV, deferential veins : SA, spermatic artery ; CA, cremasteric artery ; CM, cremaster muscle ; PP, pampiniform plexus. and (9) lymphatics. The vas deferens lies along the posterior aspect of the cord (Fig. 97), and can be detected by the firm, cord-like sensation which it gives when pinched between the thumb and finger. Mr. Birkett (Holmes's " System ,; ) gives three cases of rupture of the vas deferens during severe and sudden exertion. The duct ap- pears to have in each case given way within the abdomen at some point between the internal ring and the spot where it approaches the ureter. Re- section of part of the vas has been practised to bring about atrophy of enlarged prostate, but has XX] THE SPERMATIC CORD 487 not proved successful. The size of the cremaster muscle depends mainly upon the weight it has to suspend. In atrophy of the testicle it almost entirely disappears, while in cases of large slow- growing tumours of the gland it attains consider- able proportions. If in children or young adults the skin over the middle of the thigh just below Poupart's ligament be tickled, the testicle of the same side will usually be seen to be suddenly drawn upwards. The tickling concerns the crural branch of the genito-crural, while the motor nerve of the cremaster is the genital division of the same trunk. The interval of time that elapses between the irritation of the skin and the movement of the testicle has been appealed to as affording evi- dence of the state of nerve health and of the readiness with which nerve impulses are con- ducted. Of the arteries, the spermatic comes from the aorta and lies in front of the vas, the cre- masteric arises from the deep epigastric and lies among the superficial layers of the cord in its outer segment, while the deferential artery from the superior or in|erior vesical lies by the side of the vas (Fig. 97). The first-named vessel is the size of the posterior auricular, and the two latter the size of the supra-orbital. The spermatic artery divides into a number of branches as it reaches the testicle; these branches pass to the inner side of the epididymis, which may be removed without interfering with the blood supply of the testicle. The three arteries of the cord are divided in castration, and may all require ligature. It is advisable to secure the vessels in sections, rather than adopt the clumsy plan of involving the whole cord in one common ligature. The veins are divided roughly into two sets. The anterior is by far the larger set, runs with the spermatic artery, and forms the pampiniform plexus. The posterior set is small and surrounds the vas, running with the deferential artery. The veins of the spermatic and pampiniform plexus are very frequently varicose, and then constitute the 488 THE ABDOMEN AND THE PELVIS [Chap. affection known as varicocele. Many anatomical causes render these veins liable to this affection they occupy a dependent position, and the main vein is of considerable length, and follows a nearly vertical course ; the vessels are very large when compared with the corresponding artery, and so the vis a tergo must be reduced to a mini- mum; they occupy a loose tissue, and are lacking in support and in the aid afforded to other veins (as in the limbs) by muscular contraction; they are very tortuous, form many anastomoses, and have few and imperfect valves; they are exposed to pressure in their passage through the inguinal canal. The left veins are more frequently affected than the right. Mr. Spencer has shown that the veins of -the left cord are always much larger than those of the right. It may also be pointed out that the left testicle hangs lower than the right ; that the left spermatic vein enters the left renal at a right angle, while the right spermatic vein passes obliquely into the vena cava ; and that the left vein passes beneath the sigmoid flexure, and is thus exposed to pressure from the contents of that bowel. The female generative organs require but little notice in the present volume. The labia majora have the same pathological tenden- cies as has the scrotum, to which, indeed, they anatomically correspond. They are liable to present large extravasations of blood, are greatly swollen when oedematous, are prone to slough when acutely inflamed, and are the usual seats of elephantiasis in the female. A hernia may pre- sent in one or other ■ labium (pudendal hernia), the neck of the sac being between the vagina and the pubic ramus. " On everting one of the labia minora and pressing the hymen inwards, a small red de- pression may generally be seen on the vulva, somewhat posteriorly. It leads to the orifice for Bartholin's gland " (Doran). This gland, an oval body about \ an inch in length, lies against the XX] THE VAGINA 489 posterior part of the vaginal orifice, under the superficial perineal fascia, and covered by the fibres of the sphincter vaginae. It wastes after 30. It corresponds to the gland of Cowper in the male (Fig. 95, p. 473). Both are apt to become the sites of chronic gonorrheal inflammation. Abscess of the gland and cystic dilatation of its duct are not uncommon. The vagina is lodged between the bladder and rectum, while the upper fourth of its posterior surface is covered with peritoneum, and is there- fore in relation to the abdominal cavity. Thus it happens that the bladder, the rectum, or the small intestines may protrude into the vagina by a yielding of some parts of its walls and thus pro- duce a vaginal cystocele, rectocele, or enterocele. The anterior wall of the vagina measures a little over 2 inches, the posterior wall about 3 inches. The long axis of the canal forms an angle of 60° with the horizon, and is therefore almost parallel to the pelvic brim. The loose areolar tissue at the base of the broad ligament lies on each side of the upper extremity of the vagina. The ureter terminates in the bladder, on the upper part of the vaginal roof. The abdominal cavity may be opened through a wound of the vagina. In one or two instances of such injuries several feet of intestine have pro- truded through the vulva. In one reported case an old woman, the subject of a brutal rape, walked nearly a mile with several coils of the small bowel hanging from her genitals. From the comparative thinness of the walls that separate the vagina from the bladder and rectum, it happens that vesico-vaginal and recto- vaginal fistulae are of frequent occurrence. The vagina is very vascular, and wounds of its walls have led to fatal haemorrhage. It is very dilat- able, as can be shown when the canal is plugged to arrest haemorrhage from the uterus. The uterus weighs about one ounce. The uterine cavity and the cervical canal together Q* 490 THE ABDOMEN AND THE PELVIS [Chap. measure about 2| inches. This must be borne in mind when passing a uterine sound. The blood- vessels run transversely to the length of the uterus, so that a ligature may be placed com- pletely around the organ without affecting the circulation above or below. Ligature of the uterine artery has been practised to arrest the growth of uterine tumours. The artery rises from the in- ternal iliac \ an inch below the pelvic brim and passes to the neck of the uterus in the broad liga- ment. It is 2j inches long and loops over the ureter midway in its course. It is reached by incising the broad ligament between the Fallopian tube behind and the round ligament in front. It is found in the loose areolar tissue under the wound. The lymphatics from the fundus of the uterus and appendages pass to the lumbar glands, a few also pass along the round ligament to the in- guinal glands. The lymphatics of the cervix, which is frequently the seat of cancer, pass to the internal iliac glands on the lateral wall of the pelvis. The unimpregnated uterus is very rarely wounded, owing its immunity to the denseness of its walls, to its small size, to its great mobility, and to its position within the bony pelvis. The ovary is so placed that the outer part of the Fallopian tube turns downwards externally to it. The more common position of the ovary may be indicated on the surface of the body by the line employed to mark out the course of the common and external iliac arteries — a line drawn from the aortic bifurcation to the, femoral point (Fig. 72, p. 352). The ovary lies internally to the mid-point of this line (Fig. 91, p. 439). It lies in the angle between the external and internal iliac arteries, and may be indistinctly palpated through the vagina. Its nerves come from the 10th dorsal segment of the cord. The sensory nerves for the cervix are derived from the lower sacral segments. The lymphatics of the ovary XX] THE EECTUM 491 pass to the lumbar glands, which lie by the side of the lower part of the aorta and vena cava in the retroperitoneal tissue. The ovaries exert a very marked trophic influence on the breast; the hypertrophy of the mammae at puberty and in pregnancy depends on an internal secretion of the ovary (Starling). By their removal it was hoped that cancer of the breast might be arrested, but the procedure has not been followed by much success. At the brim of the pelvis the ovarian vessels lie within a fold of peritoneum, named the ovario- or infundibulo-pelvic ligament, for it is attached both to the ovary and to the infundi- bulum of the Fallopian tube. This ligament forms the outer part of the pedicle in ovariotomy. The rectum commences in front of the third sacral vertebra, and is about 5 inches in length (Fig. 98). It is continuous with the pelvic colon, which is invested by peritoneum and supported by a mesentery. The serous membrane gradually leaves its posterior surface, then ^ its sides, and lastly its anterior surface. Anteriorly, the peri- toneum, ^ in the form of the recto-vesical pouch, extends in the male to within 3 inches of the anus, while on the posterior aspect of the gut there is no peritoneum below a spot 5 inches from the anus. Thus, in excision of the rectum, more of the bowel can be removed on the posterior than on the anterior part of the tube without opening the peritoneal cavity. It will be seen, also, that carcinomatous and other spreading ulcers are more apt to invade the peritoneal cavity when they are situated in the anterior wall of the intestine. The lower part of the rectum, distin- guished as the anal canal, is surrounded by the internal sphincter— an involuntary muscle con- tinuous with the circular coat. In the condition of rest the anal canal, which is directed down- wards and backwards, measures lh inches, but during defaecation and when the patient bears down it assumes a shallow annular form. The canal is firmly fixed to the levatores ani and 492 THE ABDOMEN AND THE PELVIS [Chap perineal body, hence in prolapse it is the rectum above the canal which is extruded through the anus. Mr. Cripps has shown that the posterior edge of the levator ani forms a distinctly-felt free border, which crosses the rectum, nearly at a right angle, at a point from lj to 2 inches from the anus. By inserting the finger into the rectum the Pelvic Colon Upper Rectal Fold Mid. Rectal Fold Ext. Sphinc. Anal Valves Anal Columns Int. Sphinc. Fig. 98. — The stages of the rectum and the anal canal on mesial section. (Prof. A, M. Paterson.) prostate and seminal vesicles can be readily felt and examined, and that triangular surface of the bladder explored through which puncture per rectum is made (p. 468). It will be understood that the prostate, when enlarged, may encroach upon the cavity of the rectum and greatly narrow its lumen (Fig. 95). The position of the seminal vesicles with regard Bladder Vesic. Semin. Prostate XX] THE RECTUM 493 to the bowel is such that in violent attempts at defaecation they may be pressed upon by the rectal contents, and so in part emptied, producing a kind of spermatorrhoea. Defaecation also often causes much pain in inflammatory affections of the prostate and adjacent parts. The anterior surface of the rectum in the female is in relation, so far as the finger can reach, with the vagina, and, in examining the lower part of the rectum, it is convenient to pro- trude its mucous membrane through the anus by means of the finger introduced into the genital passage. The rectum is dilated and is very distensible just above the anus. In faecal accumulations it may be distended to a considerable size, and strange foreign bodies of large dimensions have been found in the ampulla. Among the latter may be mentioned a bullock's horn, an iron match - box, and a glass tumbler. By anti- peristaltic movements of the colon, such bodies may be carried towards the caecum. Thus a case has been reported by Alexander in which the handle of an umbrella, accidentally lodged in the rectum, was removed by the surgeon two weeks later from the hepatic flexure of the colon. Ex- periment has shown that when the rectum is dis- tended in the male, the recto-vesical fold of peri- toneum is raised, and the bladder is elevated and pushed forwards. In the female the fundus uteri is raised and pushed towards the symphysis. The rectum is artificially distended in suprapubic lithotomy, in order to bring the bladder into better position (p.^ 465). Normally the rectum is empty ^ except during defaecation. Advantage of this circumstance is taken in operations for the cure of ectopia vesicae where the ureters are re- moved from the exposed bladder and implanted in the rectum. If the sphincter be very gradually dilated, the entire hand, if small, may be introduced into the rectum in both males and females, but in several 494 THE ABDOMEN AND THE PELVIS [Chap. cases, when so dilated, it has been found that the sphincter never regains its normal action. The cir- cumference of the hand should not exceed 8 inches. By a semi-rotary movement, and by alternately flexing and extending the fingers, the hand can be insinuated into the commencement of the sigmoid flexure. Owing to the mobility of this part of the bowel a large extent of the abdomen may be explored through the bowel wall. The structures that can be readily felt are the kidneys, the aorta, the iliac vessels, the uterus and ovaries, the bladder and its surroundings, the pelvic brim, the sacro-sciatic foramina, the ischial spine, the sacrum, etc. In some subjects even a small hand cannot be passed beyond the reflection of the peri- toneum over the second part of the gut. In such instances the peritoneum offers a resistance like a tight garter, and prevents the farther advance of the hand without great risk of laceration of the parts (Walsham). Owing to the constrained position of the hand and the cramping of the fingers, this method of examination has proved to be of but limited service. The attachments of the rectum by means of its sheath to the pelvic fascia are not very firm ; fibrous prolongations from the perivascular sheath accompany the middle hemorrhoidal vessels, and fibrous bands from the sacrum also join its sheath. The laxity of its attachment is shown in some cases where the gut has been protruded at the anus. In excision of the rectum, also, advantage is taken of this mobility. The mucous membrane is thick, vascular, and but loosely attached to the muscular coat be- neath. This laxity, which is more marked in children, favours prolapse, an affection in which the mucous membrane of the lower part of the rectum is protruded at the anus. At the junction of the rectum and pelvic colon there is a circular fold or yalve, and often the musculature here is constricted and apparently forms a sphincter. XX] THE RECTUM 495 Above the base of the prostate (Fig. 98) the anterior wall of the rectum is folded within the lumen of the gut to form a transverse valve, often named after Houston who described it. It divides the rectum into an upper and lower part. These rectal folds or valves , especially when the gut is empty, may offer considerable resistance to the introduction of a bougie or long enema tube, and their position should be therefore borne in mind. The vessels, and especially the veins, at the lower part of the rectum are apt to become vari- cose and dilated, and form piles. The tendency to piles can in part be explained by the dependent position of the rectum, by the pressure effects of hardened faeces upon the returning veins, and by the fact that part of the venous blood returns through the systemic system (internal iliac vein) and part through the portal system (inferior mesenteric vein). This connexion with the portal trunk, which is not an extensive one, may cause the rectum to participate in the many forms of congestion incident to that vein. The veins of the rectum can also be affected by violent expiratory efforts. For the last 4 inches of the bowel, moreover, the arrangement of the vessels is peculiar, and is such as to favour vari- cosity. The arteries, u having penetrated the muscular coats at different heights, assume a longitudinal direction, passing in parallel lines towards the edge of the bowel. In their progress downwards they communicate with one another at intervals, and they are very freely connected near the orifice, where all the arteries join, by trans- verse branches of considerable size." (Quain.) The branches of the superior hemorrhoidal ar- teries terminate in the submucous tissue of the anal canal, forming vascular columns which extend to the anus. The veins form a plexus with a precisely similar arrangement. The veins beneath the mucous membrane of the anal canal perforate the muscular coat of the rectum about 496 THE ABDOMEN AND THE PELVIS [Chap. 1 inch above the anal canal. At the point of perforation they are liable to be compressed. The lymphatics of the rectum perforate the muscular coat and ascend in its sheath, where, on the posterior aspect, there may be one or more glands. They join the efferent vessels of the colon in the mesentery of the pelvic colon. They also pass to the internal iliac group of lymphatic glands on the lateral wall of the pelvis and to the lumbar glands. Hence in cancer of the lower part of the rectum these glands and the vessels leading to them are the earliest seats of secondary infections. The lymphatics of the pelvic colon pass to the glands in front of the sacrum and to others between the layers of the meso-rectum. The rectum may be most freely exposed from behind (Figs. 94 and 98). In Kraske's operation for the extirpation of cancer of the rectum an incision is made along the sacrum in the middle line, from the level of the posterior inferior iliac spine to the anus. A flap is turned out on the left side, including the skin and origin of the gluteus maximus. The attachments of the left sacro-sciatic ligaments, coccygeus, and levator ani to the sacrum and coccyx are divided and turned outwards. The lateral and median sacral arteries and a plexus of veins are raised with the fibrous tissue from the anterior surface of the sacrum by a periosteal elevator. The left halves of the 4th and 5th sacral vertebrae, with the left half of the coccyx, are removed. The 4th, 5th sacral, and coccygeal nerves are necessarily cut, but an attempt should be made to save the 3rd sacral nerve, owing to the importance of its function. The rectum is then exposed, with the hsemor- rhoidal vessels and reflection of peritoneum. By opening the peritoneal cavity part of the pelvic colon may be brought into the wound. After the diseased part is removed, with the presacral and internal iliac lymphatic glands, the upper end of the rectum is brought down and sutured to the XX] THE ANUS 497 anal part. An attempt should be made to save the levator ani and 3rd sacral nerve, in order that the integrity of the pelvic diaphragm may be maintained. For a complete removal of secondary deposits in the lymphatic system of the rectum, the sacral operation is usually com- bined with an abdominal section. The rectum is supplied with sensory and motor nerves from the 2nd, 3rd, and 4th sacral segments through the corresponding nerves. Some motor nerves are also derived from the lower two dorsal and upper lumbar segments. These nerves reach the rectum through the hypogastric and pelvic plexuses. The anus. — The skin about the anus is thrown into numerous folds, and in these ulcer or fis- sure of the anus forms. Within the anal canal the mucous membrane is thrown into vertical folds — the columns of Morgagni. When the canal is dilated they are obliterated, and as age ad- vances they become less well marked. As is shown in Figs. 93 and 98, the columns end above at the junction of canal and rectum. Between their upper extremities are small recesses, which Sir Charles Ball describes as the sinuses of Morgagni, and over them, joining the upper ends of the columns, are little folds of mucous membrane — the anal valves. When the anal canal is closed, the columns and valves come together and so make the anal orifice competent. The valves may be torn by the passing scybalous masses, and from the rent thus caused a fissure of the anus may be produced (Ball). The extreme painful- ness of these ulcers is due to the exposure of a nerve fibre at their base, and to the constant con- traction of the sphincter muscle that they excite. In 90 per cenk of cases of pruritus ani* there is a small ulcer in the posterior wall of the anal canal, near the anal valves (F. C. Wallis). Relief is given by excising the base of the ulcer, so as to divide some part of the sphincter; or by violently dilating the anus, so as to tear up the base of the ulcer and paralyse for a while the 498 THE ABDOMEN AND THE PELVIS [Chap. action of the disturbing muscle. The anal canal is lined with a stratified mucous membrane derived from an invagination or ingrowth of the epiblast or embryonic epiderm. The rectum, on the other hand, is lined with mucous columnar epithelium derived from the hypoblast of the hind gut of the embryo. The junctional line is at the upper ends of the columns of Morgagni. At their lower ends the mucous membrane joins the skin, the junction being sometimes marked by a faint white line. The anus may be torn during defaecation when the stools are hard. A case is reported of a woman who, during violent efforts at defsecation, felt something give way, and discovered faeces in her vagina. The recto-vaginal wall had ruptured 2 inches from the anus. During labour the child's head has passed into the rectum, and has been delivered per anum. An imperforate anus is the most common con- genital defect of the rectum. This condition represents an arrest of development. The forma- tion of the anus is a double process : first there is an ingrowth from the perineum, and secondly a downgrowth from the bowel, these two elements meeting and communicating at the upper end of the anal canal. In many cases of imperforate anus, only a thin anal membrane requires to be broken down to allow the free passage of faeces; but in other cases the defect is much greater, the anal canal, and even the rectum, being completely wanting. Not infrequently in such cases the rectum may communicate with the urethra in the male or with^ the vulval cleft in the female. This communication is due to the persistence of an embryonic condition. In Fig. 99 is given a diagrammatic representation of the manner in which the rectum terminated in fifty-four museum specimens of imperforate anus. In more than half of these specimens — all of which were males — the rectum terminated at the lower part of the prostate. In the female it may terminate at XX] PELVIC AND PERINEAL NEKVES 499 any point of the vagina or open in the vulval cleft. The proctodaeal invagination to form the anal canal -may be incompletely formed or absent, but a sphincter is always present.* Nerves of Pelvis and Perineum The pelvic viscera are supplied by the pelvic plexus of the sympathetic. This is joined by at 7 Specimens 33 Specimens 7 Specimens • 7 Specimens Septum Anal Canal Fig. 99. — Diagram to show the manner in which the rectum terminated in 54 cases of imperforate anus in the male. least three spinal nerves, the 2nd, 3rd, and 4th sacraL It is well known that in certain affections of the bladder, rectum, prostate, etc., pain is felt * See Keith, Brit. Med. Journ., Dec, 1908. 500 THE ABDOMEN AND THE PELVIS [Chap. along the perineum, in the penis, over the but- tock, and down the thigh. These parts are sup- plied by the pudic and small sciatic nerves, and the reason for the pain is explained by the origin of the sensory nerves for those organs from the same and adjoining segments of the spinal cord. The upper part of the rectum is provided with but little sensation, as illustrated by the passage of instruments, by the comparative painlessness of malignant and other growths high up in the bowel, and by the little inconvenience felt when the gut is distended with hardened fseces. From this apathy it has probably happened that, in the self-administration of enemata, patients have thrust the tube through the rectum into the peri- toneal cavity. The anal canal, on the other hand, is extremely sensitive. The nerve relations between the anus and the neck of the bladder are very intimate. Painful affections of the anus often cause bladder troubles, and retention of urine is very common after operations upon piles. Maladies, on the other hand, that involve the bladder neck are often associated with tenesmus and anal discomfort. This relation is maintained by the pelvic plexus, but mainly by the 4th sacral nerve. This nerve gives special branches direct to the neck of the bladder, and then goes to supply the muscles of the anus (the sphincter and levator) and the integument between the anus and the coccyx. The mucous membrane of the urethra, the muscles of the penis, and the greater part of the skin of the penis, scrotum, perineum, and anus, are supplied, from the 2nd, 3rd, and 4th sacral segments, by the pudic nerve. Thus, it will be understood that irritation applied to the urethra may cause erection of the penis (as illus- trated by chordee in gonorrhoea), or may produce contraction of the urethral muscles (as seen in some forms of spasmodic stricture). The disturb- ance caused by accumulated secretion beneath the prepuce in young children may provoke great X X] PELVIC AND TERINEAL NERVES 501 irritability of the organ, and it is well known that painful affections of the perineum and anus may be associated with priapism. The distribu- tion of the 3rd sacral segment in the perineum by means of the long pudendal nerve will explain the pain about the buttock and down the back of the thigh that is often complained of during the growth of perineal abscess and in painful affec- tions of the scrotum. This nerve crosses just in front of the tuber ischii, and may be so pressed upon b^ using a hard seat as to cause one-sided neuralgia of the penis and scrotum. It is also in close connexion with the ischial bursa, and neuralgia of the same parts has been met with in cases of inflammation involving that structure. The testicle is supplied mainly from the 10th dorsal segment by the spermatic plexus. The kid- ney is also partly supplied from the same segment. This is illustrated by the pain felt in the renal region during neuralgia of the testicle, and by the pain felt in the testicle, the vigorous retraction of that organ observed in certain affections of the kidney, such as in acute nephritis, and in the passage of renal calculi. By means of the renal plexus the testicle is brought into direct com- munication with the semilunar ganglia and solar plexus, which receives some of the terminal fibres of the vagus. This communication may serve to explain the great collapse often noticed in sudden injuries to the testicle, and especially the marked tendency to vomit, . so often observed in such lesions. # So far as its nerves are concerned, the testicle is nearly in as intimate relation with the great nerve-centre^ of the abdomen as is a great part of the small intestine, and one would expect a sudden crush of the testis to be associated with as severe general symptoms as would accompany a sudden nipping of the ileum in a rupture. Such a resemblance in symptoms is actually to be observed in practice. PARTV.-THE LOWER EXTREMITY CHAPTER XXI THE REGION OF THE HIP This region will be considered under the follow- ing heads : 1. The buttocks. 2. The region of Scarpa's triangle. 3. The hip-joint, with the upper third of the femur. 1. The Buttocks Surface anatomy. — The bony points about the gluteal region can be well made out. The crest of the ilium is distinct, as is also the anterior superior spine. The posterior superior spine is less evident, but can be readily felt by following the crest to its posterior termination. This spine is on a level with the second sacral spine, and is placed just behind the centre of the sacro-iliac articulation. The great trochanter is a conspicuous landmark. It is covered by the fascial insertion of the gluteus maximus. Its upper border is on a level with the centre of the hip-joint, and is somewhat obscured by the tendon of the gluteus medius which passes over it. The comparatively slight prominence of the trochanter in the living subject, as compared with the great projection it forms in the skeleton, depends upon the completeness with which the gluteus medius 502 Chap. XXI] THE BUTTOCK 503 and minimus fill up the hollow between the tro- chanter and the ilium. When these muscles are atrophied the process becomes very conspicuous. In fat individuals its position is indicated by a slight but distinct depression over the hip. If a line be drawn from the anterior superior spine to the most prominent part of the tuber ischii, it will cross the centre of the acetabulum, and will hit the top of the trochanter. This line, known as Nelaton's line, is frequently made use of in the diagnosis of certain injuries about the hip. McCurdy prefers a line drawn from the pubic spine at a right angle to the median line of the body ; if the femur is normal in position the pubic line should cross at or just above the great trochanter. The mid-point of this line lies over the head of the femur. The anterior superior spine or crest of the ilium may be used as fixed points from which to estimate the degree of dis- placement of the great trochanter. The ischial tuberosities are readily felt. They are covered by the fleshy fibres of the gluteus maxi- mus when the hip is extended. But when the hip is flexed, the processes become to a great extent uncovered by that muscle. The muscular mass of the buttock is formed by the gluteus maximus be- hind and by the gluteus medius and minimus and tensor vaginae femoris in front. The last-named muscle can be seen when in action, i.e. when the thigh is abducted and rotated in. The fold of the buttock crosses the obliquely placed lower border of the gluteus maximus. When the hip is fully extended, as in the erect- posture, the buttocks are round and prominent, the gluteal fold is transverse and very distinct. When the hip is a little flexed, the buttocks be- come flattened, the gluteal fold becomes oblique and then disappears. Among the early symptoms of hip disease are flattening of the buttock and loss of the gluteal fold. These symptoms depend upon the flexion of the hip, which is practically constant in every case of the malady before treat- 504 THE LOWER EXTREMITY LChap. merit. It is incorrect to say, as some books still assert, that these changes are due to wasting of the gluteal muscles, since they appear at too early a period for any considerable muscular atrophy to have taken place. It is true that these symp- toms are much exaggerated by the wasting of the muscle that occurs later on in the course of the hip affection. With regard to the vessels and nerves of the buttock, if a line be drawn from the posterior superior spine to the top of the great trochanter when the thigh is rotated in, a point at the junc- tion of the inner with the middle third of that line will correspond to the gluteal artery as it emerges from the sciatic notch. A line drawn from the posterior ^ superior spine to tin outer part of the tuber ischii crosses both the posterior inferior and ischial spines (Fig. 100). The former is about 2 inches and the latter about 4 inches below the posterior superior process. The sciatic artery reaches the gluteal region at a spot corresponding to the junction of the middle with the lower third of this line. The position of the pudic artery as regards the buttock is not difficult to indicate, since it crosses over the ischial spine in passing from the great to the small sacro- sciatic foramen. The sciatic nerve is most easily found as it escapes from beneath the gluteus maxi- mus. When the thigh is rotated outwards, so that the great trochanter approaches the ischial tuber- osity, the nerve lies midway between these two bony points, but in the unrotated position it is found at the junction of the inner and middle thirds of a line joining them. The skin over the buttock is thick and coarse, and is frequently the seat of boils. From the appearance it presents in very fully injected speci- mens, it would appear that the blood supply is not quite so free as it is in many other parts of the surface. The subcutaneous fascia is lax, and contains a large quantity of fat. It is to this fat rather XXI] THE BUTTOCK 605 than to muscular development that the buttock owes its roundness and prominence. The enor- mous buttocks of the so-called " Hottentot Venus," whose model is in many museums, depend for their unusual dimensions upon the greatly in- creased subcutaneous fat. The amount of adipose tissue normally in the part renders the buttock a favourite place for lipomata. The laxity of the superficial fascia permits large effusions, both of blood and pus, to take place in the gluteal region, and ecchymoses of the buttock can probably reach a greater magnitude in this district than is possible elsewhere. The deep fascia of the buttock, a part of the fascia lata of the thigh, is a structure of much importance. This dense membrane is attached above to the iliac crest, and to the sacrum and coccyx. Descending in front over the gluteus medius, it splits on reaching the anterior edge of the gluteus maximus into two layers, one of which passes in front of the muscle and the other behind. The gluteus maximus is thus enclosed, like the meat in a sandwich, between two layers of fascia, and the two lesser gluteal muscles are bound down within an osseo-aponeurotic space, which is firmly closed above, and only open below towards the thigh and internally at the sciatic foramina. Ex- travasations of blood may take place beneath this fascia without any discoloration of the skin to in- dicate the fact, the blood being unable to reach the surface through the dense membrane. Such extravasations may be long pent up, and, as they fluctuate, may be mistaken for abscess. Deep inflammations beneath this fascia, and especially when beneath the gluteus medius, may be associated with much pain, owing to the cir- cumstance that the inflammatory effusions will be pent up between a wall of bone on one side and a wall of dense fascia and stout muscle on the other. Abscesses so pent up may travel for a con- siderable distance down the thigh before they reach the surface, and Farabeuf relates a case 506 THE LOWER EXTREMITY [Chap. where a gluteal abscess travelled to the ankle before it broke. In other circumstances the gluteal abscess may make its way into the pelvis through the sciatic foramina, or a pelvic abscess may escape through one of these foramina and appear as a deep abscess of the buttock. The thickened part of the fascia lata that runs down on the outer side of the limb between the crest of the ileum above and the outer tuberosity of the tibia and head of the fibula below, is known as the ilio-tibial band. This band is tightly stretched across the gap between the iliac crest and the great trochanter, and if pressure be made with the fingers between these two points, the re- sistance of this part of the fascia can be appreci- ated. It is obvious that in fracture of the neck of the femur, when the great trochanter is made to approach nearer to the crest, this band will become relaxed, and Dr. Allis^ (Agnew's " Sur- gery/ 7 vol. i.) has drawn attention to this fascial relaxation as of value in the diagnosis of frac- tures of the femoral neck. The lower free edge of the gluteus maximus is oblique, and ends some way below the transverse line of the fold of the buttock. It would appear that even this great muscle may be ruptured by violence. Thus Dr. Mac- Donnell (Brit. Med. Joum., 1878) reports the case of a robust man aged 63, who, while trying to lift a heavy cart when in a crouching position, felt something give way in his buttock, and heard a snap. He fell, and was carried home, when it was found that the^ great gluteal muscle was ruptured near the junction of the muscle with its tendon. At least three bursae exist over the great trochanter, separating that process from the three gluteal muscles respectively. The most extensive is that between the insertion of the gluteus maxi- mus to the ilio-tibial band and outer surface of the great trochanter. The bursa allows the great XXI] THE BUTTOCK 507 trochanter to move freely beneath the muscle during rotation of the thigh. When this sac is inflamed much difficulty is experienced in moving the limb, and the thigh is generally kept flexed and adducted. This position means absolute rest from movement on the part of the gluteal muscles, which, when acting, would extend and abduct the limb, and bring pressure to bear upon the tender bursa. There is a bursa over the ischial tuberosity that is often inflamed in those whose employments involve much sitting, the bursa being directly pressed upon in that position. This sac is the anatomical basis of the disease known in older text-books as "weaver's bottom " or " lighter- man's bottom." # When enlarged this bursa may press upon the inferior pudendal nerve. Arteries and nerves of the buttock. — The gluteal artery is about the same size as the ulnar, and the sciatic as the lingual. The former vessel may sometimes be of much greater mag- nitude, and has led, when wounded, to rapid death from haemorrhage. Wounds of the gluteal vessels will probably involve only the branches of the artery, since the greater part of the main trunk is situate within the pelvis. Gluteal aneu- rysms are not very uncommon, and with regard to the treatment of these tumours it may be noted that the gluteal artery, or, better, the internal iliac trunk, can be compressed through the rectum. Compression so applied has been adopted for the treatment of gluteal aneurysm by Dr. Sands, of New York (Amer. Journ. Med. Set., 1881), but without much effect. Aneurysm of the commence- ment of the gluteal artery could hardly fail to provoke nerve symptoms, since the vessel runs be- tween the lumbo-sacral cord and 1st sacral nerve. Both the gluteal and sciatic arteries have been ligatured in the buttock, through incisions made directly over the course^ of the vessels. Henle has collected six cases where the femoral artery ran down along the back of the thigh to 508 THE LOWER EXTREMITY [Chap. the popliteal space in company with the great sciatic nerve. The abnormal vessel was in each case formed by an enlargement of the comes nervi ischiadici, a branch of the sciatic artery. The great sciatic nerve is a continuation downwards of the main part of the sacral plexus (Fig. 100). It is in this nerve that the form of neuralgia known as sciatica is located. A reference Post. Sup. Spine Lfsser Sacro-Sciatic Liq. Cheat Sacro Sciatic Liq. Fig. 100. — Formation and relationships of the upper part of the great sciatic nerve. to the immediate relations of this nerve will show that it may readily be exposed to many external influences. Thus, in the pelvis it may be pressed upon by various forms of pelvic tumour, and sciatica Jbe produced in consequence. Its anterior surface is in close relation with some of the princi- pal pelvic veins, and according to Erb one form of sciatica may be traced to an engorged condi- tion of these vessels. Aneurysm of certain branches of the internal iliac artery within the pelvis, XXI] THE BUTTOCK 509 sciatic hernia, and accumulation of faeces within the rectum may all cause neuralgia of this im- portant trunk. It is said to have been injured also by the pressure of the foetal head during tedious labours, and to be affected by violent movements of the. hip, a circumstance readily understood if the close relation of the nerve to the hip-joint be borne in mind. The nerve is also near enough to the surface to be influenced by external cold, and to this influence many forms of sciatica are ascribed. At the lower edge of the great gluteal muscle the trunk is still nearer to the surface, and this fact receives illustration in a case reported in Ziemssen's Cyclopaedia, where paralysis of the nerve followed its com- pression by the contracting scar of a bed-sore. Nerve stretching and injecting. — The great sciatic nerve has been frequently cut down upon and stretched for the relief of certain nervous affections of the limb (see p. 604). In connexion with this procedure it is important to know how great an amount of traction may^ be brought to bear upon this and other nerves withoutthe cord giving way. Trombetta, who has paid much attention to this matter, gives the following weights as those required > to break the ; under- mentioned nerves : great sciatic, 183 lb. ; internal popliteal, 114 lb. ; anterior crural, 83 lb. ; me- dian, 83 lb. ; ulnar and radial, 59 lb. ; brachial plexus in the neck, 48 to 63 lb. ; and brachial plexus in the axilla, 35 to 81 lb. (In each in- stance fractions have been omitted.) It must be borne in mind, however, as pointed out by Mr. Symington {Lancet, 1878), that in forcibly stretch- ing the great sciatic nerve the trunk may be torn away from its^ attachments to the soft spinal cord before a sufficient force has been applied to rup- ture the^ nerve at the point stretched. The same observation applies to other large nerve-cords, such as those of the brachial plexus, that are stretched at a spot not far from their spinal con- nexions. The great sciatic nerve may be stretched 510 THE LOWER EXTREMITY [Chap. by flexing the extended lower extremity on the belly. This measure has served to cure certain cases of sciatica. For the hypodermic injection of the great sciatic nerve to relieve sciatica, the needle is inserted to penetrate the nerve as it lies on the bone below the great sacro-sciatic notch. This point is best found by a guide line drawn from the posterior superior iliac spine to the ischial tuberosity. If the point of the needle be inserted I an inch externally to the junction of the middle and Jower thirds of this line, it lies directly over the nerve (Fig. 100). The nerve is here covered by the gluteus maximus, and lies on the ischium between the pyriformis above and the obturator internus below. The skin of the buttock is well supplied with nerves, and tactile sensibility is almost as acute in this part as it is over the back of the hand, while it is more acute than is like sensibility in such parts as the back of the neck, the middle of the thigh, and the middle of the back. The sensation of the gluteal integument is derived from a number of different nerves, and it may possibly ! interest a school-boy who has been re- cently birched to know that the painful sensations reached his sensorium through some or all of the following nerves : offsets of the posterior branches of the lumbar nerves, some branches of the sacral nerves, the lateral cutaneous branch of the last dorsal nerve, the iliac branch of the ilio-hypo- gastric nerve, offsets of the external cutaneous nerve, and large branches of the small sciatic. These nerves are derived from four spinal seg- ments — the 12th dorsal, 1st lumbar, 2nd and 3rd sacral (Fig. 133, p. 623). The 2nd and 3rd sacral also supply the sexual organs, hence the physio- logical effects which may follow application of punishment to this part, as in the celebrated case of J. J. Rousseau. It should be remembered that the pelvic vis- cera can be readily reached through the sciatic foramina from the buttock. I once saw a case at XXI] SCABPA'S TRIANGLE 511 the London Hospital of a man who was admitted with an apparently insignificant stab of the but- tock. He died in a few days, of acute peritonitis ; and the autopsy showed that the dagger had passed through the great sacro-sciatic foramen, had entered the bladder and allowed urine to escape into the peritoneal cavity. The rectum has also been damaged in injuries to the buttock, and Anger records a case of an artificial anus situate upon the buttock, that had followed a gun- shot wound, which, after involving the buttock, had opened up the caecum. It is by this route that Kraske's operation for resection of the rectum is performed and Bigby's operation on the ureter. 2. The Region of Scarpa's Triangle Surface anatomy.— The most important land- marks in the region of the groin, the anterior superior iliac spine, the spine of the pubes, and Poupart's ligament, are readily made out. To the two spines reference has already been made (p. 502). Poupart's ligament follows a curved line, with its convexity downwards, drawn be- tween these two projections. It can be felt in even stout persons, its inner half more distinctly than its outer, and even in very fat individuals its position is indicated by a slight furrow. Owing to its attachment to the fascia lata the ligament is relaxed, and rendered less distinct when the thigh is flexed and adducted, or when it is rotated in. The mid-point of a line joining the pubic with the anterior superior spine lies over the head of the femur and hip-joint. In this position a crease is often to be seen crossing the groin (Holden). The sartorius muscle is brought into view when the leg is raised across the opposite knee, and the adductor longus is rendered distinct when the thigh is abducted and the individual's attempts to adduct the limb are resisted. Even in the obese the edge of this muscle can be felt when 512 THE LOWER EXTREMITY [Chap. it is in vigorous action, and the fingers follow its border up to the very origin of muscle, just below the pubic spine. The lymphatic glands in this region can some times be felt beneath the skin, especially in thir children. The femoral ring lies behind Poupart's ligament 1 inch externally to the pubic spine (Fig. 72, p. 352). The position of the saphenous open- ing is sometimes indicated by a slight depression in the integuments. It lies just below Poupart's ligament, and its centre is about lj inches below and external to the pubic spine. In thin sub- jects the long saphenous vein can be often made out, passing to the saphenous opening. If a line be drawn from the femoral point (Fig. 72, p. 352) # to the tubercle for the adductor magnus, on the inner condyle of the femur, when the thigh is # slightly flexed and abducted, it will correspond in the upper two-thirds of its extent to the position of the femoral artery. Just below Poupart's ligament the femoral vein lies to the inner side of the artery, while the anterior crural nerve runs about J of an inch to its outer side. The profunda femoris arises about li inches below Poupart's ligament, and the internal and ex- ternal circumflex vessels come off about 2 inches below that structure. The skin over Scarpa's triangle is, unlike that of the buttock, comparatively thin and fine. The looseness of its attachment, also, to the parts immediately beneath, permits it to be greatly stretched, as is seen in cases of large femoral hernise, and in certain inguinal tumours of large size. It may even give way under severe traction, as occurred in a case reported by Berne. The patient in this case was a child aged 11, the sub- ject of hip disease. The^ thighs were flexed upon the abdomen, and, forcible extension being ap- plied to relieve the deformity, the skin gave way just below the groin, and separated to the extent of some 2 \ inches. Contracting scars in the region of the groin may produce a permanent flexing of XXII SCARPA'S TRIANGLE 513 the hip, and this result is not uncommon after deep and severe burns in this neighbourhood. It may at the same time be noted that horizontal wounds about the groin can be well adjusted by a slight flexion of the thigh. Instances are recorded where a supernumerary mammary gland, provided with a proper nipple, has been found located in the groin. Jessieu relates the case of a female who had a breast so placed, and who suckled her child from this part (see p. 213). In a few cases the testicle, in- stead of descending into the scrotum, has escaped through the crural canal, and made its appear- ance in Scarpa's triangle. It has even mounted up over Poupart's ligament after the manner of a femoral hernia, being probably urged in that direction by the movements of the limb. m The superficial fascia in this region is not very dense, and has little or no influence upon the progress of a superficial abscess. This fact receives extensive illustration, since the glands in Scarpa's triangle frequently suppurate, and yet the pus in the great majority of cases readily reaches the surface in spite of the^ circumstance that the denser layer of the superficial fascia (for in this region it is divided into two layers) covers in those glands, and should hinder the progress of pus towards the surface. Although the sub- cutaneous fat is not peculiarly plentiful in this region, yet Scarpa's triangle is a favourite spot for lipomata. The fascia lata completely invests the limb, being, so far as the front of the thigh is con- cerned, attached above to Poupart's ligament, to the body and ramus of the pubes, and the ramus of the ischium. Its integrity is interrupted only by the saphenous opening. This fascia exercises some influence upon deep abscesses and deep growths. Thus a psoas abscess reaches the thigh by following the substance of the psoas muscle, and finds itself, when it arrives at Scarpa's tri- angle, under the fascia lata. In a great number . 514 THE LOWEE EXTEEMITY [Chap, of cases it points where the psoas muscle ends, but in other and less frequent instances its pro- gress is decidedly influenced by the fascia lata, and it moves down the limb. Thus guided, a psoas abscess has pointed low down in the thigh, and even at the knee, and Erichsen reports a case where such an abscess (commencing, as it did, in the dorsal spine) was ultimately opened by the side of the tendo Achillis. muscles. — The ilio-psoas muscle, which is stretched, as it were, over the front of the hip- joint, and participates in many of the movements of that joint, is peculiarly liable to be sprained in violent exercises. Between this muscle and the thin- nest part of the hip capsule is a bursa^ which not infrequently^ communicates with the joint. When chronically inflamed, this bursa may form a large tumour on the front of the thigh that may, ac- cording to Nancrede, attain the size of a child's head. To relieve this bursa from pressure when inflamed, the thigh always becomes flexed, and a train of symptoms is produced that are not unlike those of hip disease. The deep origins of the ilio- psoas lie behind the caecum and kidney; its con- traction may elicit symptoms when these organs are diseased. The sartorius is a muscle that, from its length, peculiar action, etc., one would hardly expect to find ruptured from violence, yet in the Musee Dupuytren there is a specimen of such a rupture about the middle of the muscle united by fibrous tissue. The adductor muscles, and especially the adductor longus, are frequently sprained, or even partially ruptured, during horse exercise, the grip of the saddle being for the most part maintained by them. " Rider's sprains," as such accidents are called, usually involve the muscles close to their pelvic attachments. Much blood is often effused when the fibres are ruptured,^ and such effusion may become so dense and fibrinous as to form a mass that has been mistaken for a detached piece of the pubes (Sir Henry Morris). The term XXI] SCARPA'S TRIANGLE 515 " rider's bone " refers to an ossification of the upper tendon of the adductor longus or magnus, following a sprain or partial rupture. Cases are reported where the piece of bone in the ten- don was i an inch, 2 inches, and even 3 inches long. Blood-vessels.— The femoral artery occupies so superficial a position in Scarpa's triangle that it is not infrequently wounded. The vessel also has been opened up by cancerous and phagedenic ulcerations of this part, the occurrence leading to fatal haemorrhage. Pressure is most conveniently applied to the artery at a spot immediately below Poupart's ligament, and should be directed back- wards, so as to compress the vessel against the pubes and adjacent parts of the hip capsule. Lower down, compression should be applied in a direction backwards and outwards, so as to bring the artery against the shaft of the femur, which lies at some # distance to its^ outer side. Pressure rudely applied by a tourniquet may cause phle- bitis by damaging the vein, or neuralgia by con- tusing the anterior crural nerve. From the proximity of the artery and vein, it happens that arterio-venous aneurysms follow- ing wounds have been met with in this situa- tion. Aneurysm is frequent in the common femoral, and many reasons can be given why that vessel should be attacked. It is just about to bifurcate into two large trunks, its superficial position exposes it to injury, it is greatly influ- enced by the movements of the hip, and its coat may, if diseased, be damaged by those movements, if excessive. Phlebitis of the femoral vein has in many cases followed contusion of the vessel in its upper or more superficial part, and a like result has even followed from violent flexion of the thigh. The long saphenous vein is often varicose, and one form of the varicosity^ is said to depend upon constriction of the vein by an unduly narrow saphenous opening. That varicose veins are, in 516 THE LOWEE EXTREMITY [Chap. the majority of cases, of congenital origin is now very generally allowed. Nerves.— The anterior crural lies on the ilio- psoas muscle, and it is said that neuralgia, and even paralysis of the nerve, may follow upon in- flammation of that muscle and upon psoas abscess. The superficial position of the trunk exposes it to injury. The genito=crural nerve (the nerve that supplies the cremaster muscle) gives a sensory fila- ment to the integument of the thigh in Scarpa's triangle. Irritation of the skin over the seat of this nerve, which is placed just to the outer side of the femoral artery, will cause, in children, a sudden retraction of the testicle. The same result is often seen in adults, also, on more severe stimu- lation. In this manner the condition of the second lumbar segment of the cord may be tested. The lymphatic glands in this region are numerous, and, as they are frequently the seat of abscess, it^ is important to know whence they derive their afferent vessels. They are divided into a superficial and a deep set. The super- ficial set, averaging from 10 to 15 glands, is ar- ranged in two groups, one parallel and close to Poupart's ligament (the horizontal series), the other parallel and close to the long saphenous vein (the vertical series). The deep set, about 4 in number, are placed along the femoral vein, and reach the crural canal. The inguinal glands receive the following lym- phatics : — Superficial vessels of lower limb = vertical set of superficial glands. Superficial vessels of lower half of abdomen = middle glands of horizontal set. Superficial vessels from outer surface of but- tock = external glands of horizontal set. From inner surface of buttock = internal glands of horizontal set. (A few of these vessels go to the vertical glands.) Superficial vessels from external genitals — horizontal glands, *ome few going to vertical set. XXIJ SCARPA'S TRIANGLE 517 Superficial vessels of perineum and anus = vertical set. Deep lymphatics of lower limb = deep set of glands. The lymphatics that accompany the obturator, gluteal, and sciatic arteries, and the deep vessels of the penis, pass to the pelvis and have no con- nexion with the inguinal glands. The only super- ficial lymphatics of the lower extremity which do not pass direct to the inguinal glands are those which drain the outer side of the ankle and pos- terior aspect of the leg. The vessels from these areas accompany the short saphenous vein and end in the popliteal glands; the efferent vessels from these glands pass to the deep inguinal set. One of the deep glands lies in the crural canal and upon the septum crurale. Being surrounded by dense structures, it is apt to cause great dis- tress when inflamed and great pain when the hip is moved. In some cases, by reflex disturbance, it has produced symptoms akin to those of strangulated hernia. Some branches of the an- terior crural nerve lie over the inguinal lymph glands, and Sir B. Brodie reports a case in which these branches were stretched over two enlarged glands, like strings of a violin over its bridge, so that violent pain and convulsive movements were set up in the limb. The efferent vessels from the inguinal glands pass through a chain of lymphatic glands stretch- ing along the course of the external and common iliac vessels. Three of these glands lie imme- diately above Poupart's ligament. The efferent vessels of the internal iliac group of glands, into which the pelvic lymphatics drain, join the chain along the common iliac vessels. The lumbar glands receive the lymph from the iliac groups and pass it on by the right and left lumbar trunks to the receptaculum chyli. Elephantiasis Arabum is more common in the lower limb than in any other part, and leads to an enormous increase in the size of the extremity 518 THE LOWEE EXTREMITY [Chap. (Cochin or Barbadoes leg). Its pathology is in^l timately concerned with the crural lymphatics. I The lymphatics are obstructed by a small thread- worm, Filaria sanguinis hominis. The lymph-1 vessels and lymph-spaces in the connective tissue] become greatly distended, and the elements of the connective tissue hypertrophied. 3. The Hip-Joint The hip-joint is of considerable strength (Fig. | 101), not only on account of the shape of the | articulating bones, which permits of a good ball- and-socket joint being formed, but also because of j the powerful ligaments that connect them and the 1 muscular bands that directly support the capsule. \ These advantages, however, are to some extent counterbalanced by the immense leverage that can be brought to bear upon the femur, and the numerous strains and injuries to which the joint is subjected, as the sole connecting link between the trunk and the lower limb. The acetabulum is divided into an articular . and a non-articular part. The former is of horse-shoe shape, and varies from 1 inch to \ an inch in width. The bone immediately above the articular area is very dense, and through it is transmitted the superincumbent weight of the trunk. The non-articular part corresponds to the area enclosed by the horse-shoe, and is made up of very thin bone. It is, however, rarely frac- tured by any violence that may drive the femur up I against the pelvic bones, since no ordinary force can bring the head of the thigh-bone in contact with this segment of the os innominatum. Pelvic abscesses sometimes make their way into the hip-joint through the non-articular part of the acetabulum, and an abscess in the hip-joint may reach the pelvis by the same route. But both such circumstances are rare. In some cases of de- structive hip disease the acetabulum may separate into its three component parts. Up to the age of puberty these three bones are separated by the XXI] THE HIP-JOINT 519 Y-shaped cartilage. At puberty the cartilage begins to ossify, and by the eighteenth year the acetabulum is one continuous mass of bone. The Fig. 101.— Vertical section of the upper third of the thigh showing the structures in relationship with the hip- joint. {After Br -aune.) Muscles.— 1 Psoas ; 2 iliacus ; 3, gluteus medius ; 4, gluteus minimus ; 5, obturator internus ; 6, obturator externus ; 7, ilio-psoas ; 8, pec- tineus ; 9, adductor magnus ; 10, adductor brevis ; 11, gracilis ; 12, adductor longus ; 13, vastus internus ; 14, vastus externus. a, anterior crural nerve ; b, external iliac artery ; c, external iliac vein ; d, obturator nerve ; e, obturator artery ; /, branches of obturator vessels to hip- joint ; g, internal circumflex vessels ; h, deep femoral vessels ; i, branch of external circumflex : j, bursa over great trochanter ; k, reflections of capsule to neck of femur ; m, asc. ramus of pubes ; ?i, peritoneum ; o, iliac fascia. breaking-up of the acetabulum by disease, there- fore, is only possible before that year. 520 THE LOWER EXTREMITY [Chap. The manner in which the various movements at the hip are limited may be briefly expressed as follows. Flexion, when the knee is bent, is limited by the contact of the soft parts of the groin, and by some part of the ischio-femoral ligament ; when the knee is extended the movement is limited by the hamstring muscles. Extension is limited by the ilio-femoral or Y ligament. Abduction, by the pubo-femoral ligament. Adduction of the flexed limb is limited by the ligamentum teres and ischio- femoral ligament, and of the extended limb by the outer fibres of the ilio-femoral ligament and upper part of the capsule. Rotation outwards is resisted by the ilio-femoral ligament, and especi- ally by its inner part, during extension, and by the outer limb of that ligament and the liga- mentum teres during flexion. Rotation inwards is limited during extension by the ilio-femoral ligament, and during flexion by the ischio-femoral ligament and inner part of the capsule. # The structures which take the chief part in maintain- ing the integrity of the joint, however, are not the ligaments but the strong muscles which sur- round and act on the joint. Atmospheric pres- sure takes no part, for the fat at the transverse notch is readily drawn into the acetabulum to make good any space vacated by the femoral head in all normal movements of the hip-joint. Hip-joint disease.— Owing to its deep position and its thick covering of soft parts (Fig. 101), this articulation is able to escape, to a great extent, # those severer injuries that are capable of producing acute^ inflammation in other joints. Acute synovitis is indeed quite rare in the hip, and the ordinary disease or the part is of a dis- tinctly chronic character. It follows, also, from the deep position of the articulation that pus, when it is formed in connexion with disease, re- mains pent up, and is long before it reaches the surface. Suppuration in this region, therefore, is often very destructive. When effusion takes place into the joint, the swelling incident thereto XXI] HIP-JOINT DISEASE 521 will first show itself in those parts where the hip capsule is the most thin. The thinnest parts of the capsule are in front and behind; in front, in the triangular interval between the inner edge of the Y ligament and the pubo-femoral ligament, and behind at the posterior and lower part of the capsule. It is over these two districts that the swelling first declares itself in cases of effusion into the joint, and as these parts are readily ac- cessible to pressure, it follows that they^ corre- spond also to the regions where tenderness is most marked and is earliest detected. In chronic hip disease, certain false positions are assumed by the affected limb, the meaning of which it is important to appreciate. These posi- tions may be arranged as follows, according, as nearly as possible, to their order of appearing : (1) The thigh is flexed, abducted, and a little everted; and associated with this there is (2) apparent lengthening of the limb and (3) lordosis of the spine; (4) the thigh is adducted and in- verted, and incident to this there is (5) apparent shortening of the limb; (6) there is real shorten- ing of the limb. (1). The first position is simply the posture of greatest ease. It depends mainly upon the effu : sion into the joint. If fluid be forcibly injected into a hip-joint the thigh becomes flexed, abducted, and a little everted. In other words, the articula- tion holds the most fluid when the limb is in this position, and the patient places it there to relieve pain by reducing the^ tension within the capsule to a minimum. Flexion is the most marked fea- ture in this position. Its effect is pronounced. It relaxes the main part of the Y ligament, which, when the limb is straight, is drawn as^ an unyield- ing band across the front of the joint. Abduc- tion relaxes the outer limb of this ligament and the upper part of the capsule. Eversion slightly relaxes the inner limb of the Y ligament and the ischio-femoral ligament. The latter movement is the least marked, since eversion, even in the flexed 522 THE LOWER EXTREMITY [Chap. position of the joint, is resisted by the outer part of the Y Jigamenk Any but a moderate degree of abduction would be limited by the pubo-femoral ligament, especially as that band is rendered most tense when abduction is combined with flexion and rotation outwards. The attachments of the psoas muscle are ap- proximated and its pressure over the joint relaxed. (2). The apparent lengthening is due to the tilting down of the pelvis on the dis- eased side, and is the result of the pa- tient's attempts to overcome the effects of the position just described. The limb is shortened by flexion and abduc- tion, and to bring the foot again to the ground and to re- store the natural parallelism of the limbs, the pelvis has to be tilted down on the affected side. Thus an apparent lengthening is pro- duced, which is seen when the patient lies upon a bed and the abduction is made to dis- appear. Real lengthening of the limb can scarcely be produced by the effusion into the joint. By forcible injection into the joint Braune could only separate the articulating surfaces about Jth of an inch. (3). The lordosis, or curving forwards, of the spine occurs in the _ dorso-lumbar region. It depends upon the flexion of the limb, and is the a a Fig. 102. — Diagram to show the mode of production of lordosis in hip disease. A, Femur flexed at hip, pelvis (repre- sented by the dotted line) straight, and spine normal. B, The flexion concealed or overcome by lordosis of the spine ; the pelvis rendered oblique. XXII HIP-JOINT DISEASE 523 result of an attempt to conceal that false position, or at least to minimize its inconveniences (Fig. 102). When the thigh is flexed at the hip by disease, the lower limb can be made to appear straight by simply bending the spine forwards in the dorso-lumbar region without effecting the least movement at the disordered joint. Indeed, the movement proper to the hip is in this case trans- ferred to the spine. A patient with a flexed hip as the result of disease can lie on his back in bed, with both limbs apparently perfectly straight, he having concealed the flexion, as it were, by pro- ducing a lordosis of the spine. If the lordosis be corrected and the spine be made straight again, then the flexion of the hip reappears, although all the time the hip-joint has been absolutely rigid. This lordosis generally appears a little late in the disease, and after the limb has become more or less fixed in the false position by con- traction of the surrounding muscles. (4). Sooner or later, in hip disease, the thigh becomes adducted and inverted, while it still remains flexed. The head of the femur then rests on the upper and posterior part of the acetabu- lum, quite half of it being outside the socket. This position has been variously accounted for. According to one theory, it is due to softening and yielding of some parts of the inflamed capsule. It is more probable that this false position, and especially the adduction, depends upon muscular action. The muscles about the joint are in a state of irritability. They are contracted by a reflex action that starts from the inflamed articu- lation, and since the adductor muscles are sup- plied almost solely by the obturator nerve, it is not unreasonable to expect them to be especially disturbed if the large share that the obturator nerve takes in the supply of the hip be borne in mind. The whole matter, however, requires further investigation. (5). Apparent shortening of the limb is due to tilting up of the pelvis on the diseased side, and 524 THE LOWER EXTREMITY LChap. bears the same relation to adduction that ap- parent lengthening bears to abduction. To over- come the adduction, and to restore the natural parallelism of the limbs, the patient tilts up one side of his pelvis (Fig. 103). It thus happens that a patient with his femur flexed and adducted Jby disease may lie in bed with both limbs quite straight and parallel, but with one limb obviously C A. B ABC Fig. 103. — A, Parts in normal position. B, The adduc- tion corrected by tilting up the pelvis. G, Femur adducted AC, Line of pelvis ; AB, limb on diseased side ; CD, limb on sound side ; E, the spine. It will be found that in Figs. B and C the angle at A is the same in the two cases. shorter than the other. , The flexion in such a case is concealed by lordosis, and the adduction by the tilting of the pelvis. In some cases of simul- taneous disease in both hip-joints that has been indifferently treated, both thighs may remain adducted. The limbs are unable, of course, to remedy their position by the usual means, when the disease^ is double, and consequently one limb is crossed in front of the other, and the peculiar XXI] HIP-JOINT DISEASE 525 mode of locomotion known as " cross-legged pro- gression ;; is produced. (6). The real shortening depends upon destruc- tive changes in the head of the bone, or upon dislocation of the partly disintegrated head on to the dorsum ilii, through yielding of the softened capsule and the crumbling away of the upper and posterior margin of the acetabulum. When^ hip disease commences in the bone it usually involves the epiphyseal line that unites the head of the femur to the neck. This line is wholly within the joint, and the epiphysis that forms the head unites with the rest of the bone about the eighteenth or nineteenth year (Fig-. 101). It is well known that patients with hip disease often complain of pain in the knee. This referred pain may be so marked as entirely to withdraw attention from the true seat of disease. Thus I once had a child sent to the hospital with a sound knee carefully secured in splints, but without any appliance to the hip, which was the seat of a somewhat active inflammation. This referred pain is easy to understand, since the two joints are supplied from the same segments of the spinal cord. In the hip, branches from (1) the anterior crural enter at the front of the capsule ; (2) branches from the obturator at the lower and inner part of the capsule ; and (3) branches from the sacral plexus and sciatic nerve at the pos- terior part of the joint. In the knee, branches from (1) the anterior crural (nerves to vasti) enter at the front of the capsule ; (2) branches from the obturator at the posterior part of the capsule ; and (3) branches from the internal and external popliteal divisions of the great sciatic nerve at the lateral and hinder aspects of the joint. Pain, therefore, in the front of the knee, on one or both sides of the patella, has probably been referred along the anterior crural curve, and pain at the back of the joint along the obturator or sciatic nerves. 526 THE LOWER EXTREMITY LChap. In hysterical individuals joint disease may be imitated by certain local nervous phenomena, the articulation itself being quite free from struc- tural change. This affection most commonly shows itself in the hip or knee, and the " hys- terical hip," or "hysterical knee," takes a promi- nent place in the symptomatology of hysteria. It is not quite easy to understand why these two large joints should be so frequently selected for the mimicry of disease. Hilton has endeavoured to explain the fact upon anatomical grounds, having reference to the nerve supply of these joints in relation to the nerve supply of the uterus. The uterus is mainly supplied by an offshoot from the hypogastric plexus, and by the 3rd and 4th sacral nerves. Now, the hypogas- tric plexus contains filaments derived from the lower lumbar nerves; and from the same trunks two nerves to the hip and knee (the anterior crural and obturator) are in great part derived. The great sciatic also contains a large portion of the 3rd sacral nerve. The common origin of the joint and uterine nerves forms the basis of Hilton's explanation of the relative frequency of hysterical disease in the large articulations of the lower limb. The explanation, however, is un- satisfactory, since the uterus receives many of its nerves from the ovarian plexus, and the^ theory is founded upon the unwarranted supposition that all hysterical disorders are associated with some affection of the uterus or its appendages. More recently Head has revived a modified form of Hilton's theory. He explains the connexion not through an anatomical association of nerves, but through an association of the centres from which nerves arise in the spinal cord. The spipal seg- ments from which the obturator nerve arises, the second, third, and fourth, contain no visceral nerves, and, therefore, cannot be associated with visceral conditions. On the other hand, the sacral segments from which the great sciatic nerve arises are those which supply the pelvic viscera. XXI] FKACTURES OF THE FEMUR 527 Fractures of the tipper end of the femur may be divided into (1) fractures of the neck wholly within the capsule; (2) fractures of the base of the neck not wholly within the capsule; (3) fractures of the base of the neck involving the great trochanter; (4) separations of epiphyses. It can be scarcely possible, apart from gunshot in- juries, to fracture the neck of the femur by direct violence, owing to the depth at which the bone is placed, and the manner in which it is protected by the surrounding muscles. The violence, there- fore, that causes the lesion is nearly always sup- plied indirectly to the bone, as by a fall upon the feet or great trochanter, or by a sudden wrench of the lower limb. (1). The true intracapsular fracture may involve any part of the cervix within the joint, but is most usually found near the line of junction of the head with the neck. This fracture is most common in the old, in whom it may be produced by very slight degrees of violence. The liability of the # aged to this lesion is explained upon the following grounds : The angle between the neck and shaft of the femur, which is about 130° in a child, tends to diminish as age advances, so that in the old it is commonly about 125°. In certain aged subjects, as a result probably of gross degenerative changes, this angle may be reduced to a right angle. This diminution of the angle certainly increases the risk of fracture of the neck of the bone. There is often, besides, in ad- vanced life, much fatty degeneration of the can- cellous tissue of the cervix with thinning of the compact layer. Dr. Merkel (Amer. Journ. Med. Sci., 1874) also asserts that in old persons there is an absorption of that process of the cortical sub- stance which runs on the anterior part of the neck between the lesser trochanter and the under part of the head. This process he calls the "calcar femorale, ;; and maintains that it occupies the situation at which the greatest pressure falls when the body is erect (Fig. 104). These fractures are but 528 THE LOWER EXTREMITY TChap. rarely impacted; but when impacted, the lower fragment, represented by the relatively small and compact neck, is driven into the larger and more cancellous fragment made up of the head of the bone. The fracture may be subperiosteal, or the fragments may be held together by the reflected portion of the capsule. These reflected fibres pass along the neck of the bone from the attachment of the capsule at the femur to a point on the cervix much nearer to the head. " These reflected fibres occur at three places, one corresponding in position to the middle of the ilio-femoral liga- ment, another to the pectineo-femoral, and the third on the upper and back part of the neck ,? (Sir Henry Morris). Fractures of this part very rarely indeed unite by bone. Blood is brought to the head of the femur by vessels in the neck of the bone, in the reflected parts of the capsule, and in the ligamentum teres. When the first two sources of blood supply are cut off by the fracture, the third does not appear to be sufficient to allow of great reparative changes taking place in the upper fragment. The fractures that heal by bone are probably either impacted, or subperiosteal, or not wholly intracapsular. (2). In connexion with fractures at the base of the neck, it must be remembered that a wholly extracapsular fracture of the neck of the femur is an anatomical impossibility. If the fracture is wholly without the capsule, then it must involve a part of the femoral shaft, and cannot be entirely through the cervix. In the front of the bone the capsule is attached to the femur along the inter- trochanteric line, and strictly follows the line of junction between the cervix and the shaft. Be- hind, the capsule is inserted into the neck about \ an inch above the posterior intertrochanteric line. It is therefore possible for a fracture of the neck to be extracapsular behind, but not in front, and many of these lesions at the base of the neck have this relation to the capsule. The Y liga- ment is so thick, being in one place about \ of an XXI] FRACTURES OF THE FEMUR 529 inch in thickness, that a fracture involving the base of the cervix may run between its fibres at their attachment, and be neither extra- nor intra- capsular. When fractures at the junction of the neck and shaft are impacted, the upper fragment, represented by the compact and relatively small cervix, is driven into the cancellous tissue about the great trochanter and upper end of the shaft (Fig. 104). As a result of this impaction the Ant. Dense Layer Calcar Femorale Ant. Fragment of Great Trochanter Fig. 104. — The calcar femorale and its relationship to impacted fractures of the neck of the femur. {Ralph Thompson. ) trochanter may be split up, and the bones may become free again through the extent of this splintering. The impacted end of the cervical fragment is shaped like a chisel; the qalcar femorale forming its cutting edge (R. Thompson) With regard to the symptoms of a fracture of the neck of the femur, the following may be noticed : (a) The swelling often observed in the front of the limb, just below Poupart's liga- ment, is due either to effusion of blood into the joint or to projection of the fragments against 530 THE LOWER EXTREMITY [Chap. the front of the capsule; (6) the shortening is brought about by the glutei, the hamstrings, the tensor vaginae femoris, the rectus, sartorius, and ilio-psoas, the adductors, gracilis, and pectineus; (c) the eversion, or rotation outwards of the limb, is mainly due to two causes : (i) the weight of the limb, which causes it to roll outwards, as is seen in persons insensible or asleep, the line of gravity passing through the outer part of the thigh ; (ii) the fact that the compact tissue on the posterior aspect of the neck is much more fragile than that on the anterior aspect. Thus the cervix is often more extensively fractured behind than in front, or the fracture may be impacted behind but not in front, and in either case the limb will tend to become everted. As a third cause may be mentioned the action of the ilio-psoas, the adductor and pectineus muscles, and of the small rotator muscles, all of which will tend to roll the femur outwards. (3). Fracture of the base of the neck, involving the great trochanter. In this lesion the head, the cervix, and a part of the great trochanter are separated from the shaft and the rest of the trochanter. (4). Separation of epiphyses. There are three epiphyses in the upper end of the femur ; one for the head, which unites between 18 and 19 years of age; one for the lesser trochanter, which unites about 17; and one for the greater trochanter, which unites about 18. # The neck is formed by an extension of ossification from the shaft (Fig. 105). The epiphysis for the head is secured against separation by being shaped like a cap, by its epiphyseal line being arranged trans- versely to the axis of the femur, and also by its intracapsular position. The epiphysis, t however, is subject to a peculiar form of dislocation which gives rise to the condition of coxa vara. The epiphysis gradually tilts downwards so that the neck of the femur appears to sink under the weight of the body, coming to form an angle of XXI] DISLOCATIONS OF THE HIP 531 90° or less with the shaft of the femur. It occurs in adolescents. Owing to the prominence of the trochanter and shortening of the limb i which necessarily result, the condition may be mistaken for a fracture of the neck of the femur or a con- genital dislocation of the hip-joint. The great trochanter may be separated. The epiphyseal lines of the head and great trochanter are continuous until the neck is ossified (see Fig. 105). Dislocations of Ihe hip. — These injuries are comparatively rare, on account of the great ABC D Fig. 105. — Illustrating the ossification of the upper ex- tremity of the femur and the condition of coxa vara. {After Elmslie.) A, The upper extremity at birth. B, „ „ at 2nd year. C, „ „ at 4th year. D, „ „ of a femur from a subject of coxa vara. strength of the articulation, and when they occur in a healthy joint are always the result of a con- siderable degree of violence. A dislocation of the hip may be congenital, or may be spontaneously produced by muscular efforts, as shown in a few rare cases, or may be the result of disease of the articulation. Congenital dislocation of the hip~ joint is due in most instances to a failure in the development of the acetabulum. In such cases the acetabulum retains the shallow character seen during the second month of foetal life. The out- growth of the acetabular rim fails, especially in the iliac part. The acetabular cavity becomes 532 THE LOWEE EXTREMITY [Chap. filled up by the duplication of the capsule, which is unduly lax (Fig. 106). The round ligament may be intact or deficient. The head of the femur becomes flat and the neck short, and the bone slips backwards on the dorsum ilii when the child learns to walk. The weight of the body is sup- ported by the muscles and ligaments round the hip-joint. If replaced the head again slirjs from the shallow cavity. In time osteophytic out- growths from the ilium lead to the formation of a new cavity. The deformity is evidently corre- lated with the development of the female sexual CwutealMuscles Qrt TR0C/1A/1TEB Fig. 106. — Congenital dislocation of the hip. From a specimen presented to the London Hospital Medical College Museum by Mr. Openshaw. It was obtained from a child aged 4 years. organs, for it occurs nearly nine times more frequently in female than in male children (Fairbanks). In dislocations due to violence the head of the bone may be found displaced in four directions, producing the four regular dislocations of the hip. In two the head of the femur is posterior to a line drawn vertically through the acetabulum, and in the other two it is found anterior to that line. (1) Backwards and upwards. Head rests upon ilium, just above and behind acetabulum. The "dislocation upon the dorsum ilii. n (2) Back- wards. Head rests upon ischium, and, as a rule; XXII DISLOCATIONS OF THE HIP 533 about on a level with the ischial spine. The " dis- location into the sciatic notch." (3) Forwards and downwards. Head rests on thyroid foramen. The " obturator or thyroid dislocation" (4) For- wards and upwards. Head rests upon the body of the pubes, close to its junction with the ilium. The " dislocation upon the pubes" The above arrangement represents also the order of frequency of these luxations, No. 1 being the most common dislocation of this part, and No. 4 the most rare. General facts.— In all these dislocations^ the hip, (a) the luxation occurs when the limb is in the position of abduction ; (b) the rent in the capsule is always at its posterior and lower part; (c) the head of the bone always passes at first more or less directly downwards ; (d) the Y ligament is untorn, while the ligamentum teres is ruptured. (a) It is maintained that in all luxations at the hip, the pelvis and femur are in the mutual position of abduction of the latter at the time of the accident. The direction of the neck of the femur and of the acetabulum, and the position of the cotyloid notch, all favour dislocation in the abducted posture. The lower and inner part of the acetabulum is very shallow, and the lower and posterior part of the capsule is very thin. In abduction, the head of the bone is brought to the shallow part of the acetabulum; it moves more than half out of that cavity ; it is supported only by the thin weak part of the capsule, and its further movement in the direction of abduction is limited only by the pubo-femoral ligament, a somewhat ^ feeble band. In abduction the round ligament is slack, and in abcjuction with flexion both the Y ligament and the ischio-femoral liga- ments are also relaxed. In the position of abduc- tion, therefore, no great degree of force may be required to thrust the head of the bone through the lower and posterior part of the capsule and displace it downwards. (b) The above being allowed, it will be under- 534 THE LOWER EXTREMITY [Chap. stood that the rent in the capsule is always at its posterior and lower parts. " Generally the rup- ture is jagged and irregular, but will be found to extend more or less directly from near the shallow rim of the acetabulum, across the thin portion of the capsule to the femur near the small trochanter, and then to run along the back of the ligament close to its attachment to the neck of the bone" (Sir Henry Morris). (c) If the position of the limb at the time of the accident be considered, it will be seen that the femur will in every case be displaced downwards. There is, indeed, but one primary dislocation of the hip — a luxation downwards. The four forms given above are all secondary, the bone having in each instance first passed downwards before it moved to any of the positions indicated. This point has been ably demonstrated by Sir Henry Morris, whose account of the anatomy of hip dis- locations is most valuable. The head having left the acetabulum, its ultimate destination will de- pend upon the character of the dislocating force. " If the limb be flexed on the pelvis, and rotated inwards, or the pelvis be correspondingly moved on the thigh at the moment of displacement, the head of the femur will take a backward course and rest on the dorsum ilii or some part of the ischium. On the other hand, extension and out- ward rotation will cause the head of the bone to travel upwards and forwards, and what is called a dislocation on to the pubis will occur. ^ . . . If the dislocation is neither accompanied nor followed by rotation or fixed flexion or extension, the head of the femur will remain below the acetabulum, and will occupy the foramen ovale if it takes a slightly forward direction in its descent, . or some position near the tuberosity of the ischium if it leaves its socket in a backward and downward direction" (Morris). (d) The Y ligament is never torn in any regu- lar dislocation. It is saved by its great density and the circumstance that it is probably more XXI] DISLOCATIONS OF THE HIF 535 or less relaxed at the time of the luxation. The method of reducing these dislocations by mani- pulation depends for its success mainly upon the integrity of the Y ligament, which acts as the fulcrum to a lever of which the shaft of the femur is the long arm and the neck the short. In the backward luxations the head is behind the Y ligament, and in the forward displacements in front of it. The anatomy of each form of hip dislocation.— Nos. 1 and 2 : The dislo ca- tions backwards (Fig. 107).— The femoral head, having been dis- placed in the way indicated, is carried towards the dorsum or sciatic notch by the glutei, ham- string, and ad- ductor muscles. Fig. 107.- Dislocation upon the The bone having dorsum ilii. [Bigelow.) taken a general direction backwards, the height to which it ascends depends mainly upon the nature of the dislo- cating force, and also upon the extent of the rupture in the capsule v and the laceration of the obturator internus tendon and other small external rotators. The dorsal dislocation is, therefore, a more advanced grade of the sciatic. The more extreme the flexion and inward rota- tion at the time of the accident, the more likely is the dislocation to be sciatic. More moderate flexion and inward rotation will produce a luxa- tion upon the dorsum. In the dorsal luxation 536 THE LOWER EXTREMITY [Chap. the head is above the obturator interims tendon, while in the sciatic form it is below it (Bigelow). Morris has been able to find but one case of direct dislocation of the femur backwards on to the ischium. In every instance it passes first in a downward direction, and then backwards. Bigelow states that there is no evidence to show that the head of the femur has even been actually displaced into the sciatic notch. In these back- ward dislocations the ilio-psoas muscle is greatly stretched. The quadratus fe- moris, the obtura- tors, the gemelli, and the pyriformis are more or less lacerated. The pec- tineus is often torn, and the glutei mus- cles even may be ruptured in part. The great sciatic nerve may be com- pressed between the femoral neck and the rotator muscles, or between the head of the bone and the tuber ischii. In both of the backward luxations there is shorten- ing due to the circumstance that the line between the anterior superior spine and the femoral condyles is lessened by the displacement back- wards of the bone, with the additional shorten- ing, due to the circumstance that the line between by the passing of the femoral head above the level of the acetabulum. The adduction^ and inversion in the main depend upon the position of the head and cervix, which must follow the plane Fig. 108. - Obturator or thyroid dislocation. {Bigeloiv.) XXI] DISLOCATIONS OF THE HIP 537 of the bone upon which they lie. This position is maintained by the tense Y ligament. The damage done to the chief external rotators places them also hors de combat. The flexion is due to the tension of the Y ligament and of the ilio-psoas muscle. Nos. 3 and 4 : The dislocation forwards. — ] acetabulum simply the head after leaving moves a little for- wards along the inner edge of the socket, the thyroid luxation is produced (Fig. 108). If it goes farther and moves upwards, the pubic displacement will result (Fig. 109). The latter dislocation is therefore but an advanced form of the former. Whether the head will remain in the thyroid foramen or ascend on to the pubes depends on whether extension and rotation outwards ac- company the displace- ment. If these occur the pubic form is produced. In these injuries the pectineus, gracilis, and adductors will be more or less torn, while the ilio-psoas, glutei, and pyriform muscles are much stretched. The obturator nerve may be stretched or torn, and in the pubic luxation the anterior crural nerve may be involved. The ab- duction and eversion of the limb noticed in these luxations depend partly upon the position of the head of the bone, fixed more or less by the Y liga- ment, and partly upon the action of the gluteal muscles and some of the small external rotators, Fig. 109.— Dislocation upon the pubes. (Bigelow.) 538 THE LOWEE EXTREMITY [Chap. which are tightly stretched. The flexion of the limb is mainly due to the stretching of the ilio- psoas muscle. In the thyroid luxation the extremity is said to be lengthened. This lengthening is, however, only apparent, and is due to the tilting down of the pelvis on the injured side. In the pubic dislocation there is shortening, the head being carried above the acetabular level. Of the modes of reducing these dislocations by manipulation little can be said here. The more usual proceedings may be briefly summarized as follows : First. — Flex the thigh in the^ adducted position in luxations Nos. I 1 and 2. 1 To relax the Flex the thigh in the f ligament, abducted position in luxations Nos. 3 and 4. ci 77 r\- j , . /To bring back the S^o^.-Circumduct out in head t * the rent Nos. 1 and 2. . J in the ule b Circumduct in in fVlQ oarna * hot fllQ J f Nos. 3 and 4. the same route that it has escaped. Thirdly. — Extend in all cases. To induce the head to enter the acetabulum again. In reducing dislocations of the hip it may be noted that the internal condyle of the femur faces in nearly the same direction as the head of the bone. In amputation of the thigli at the hip- joint many methods may be employed, but there is a consensus of opinion that it is wise to design the operation so that the femoral vessels may be secured in the preliminary incision. In dis- articulation by a racquet-shaped incision, the part representing the handle is placed over the upper 3 inches of the femoral artery, com- XXI! AMPUTATION AT HIP-JOINT 539 mencing above at Poupart's ligament, and the elliptical part is carried round the inner side of the limb, 4 inches below the pubic spine, and brought up on the outer side, below the great trochanter. The surface markings for the femoral artery are given at p. 512; the origin of the deep femoral artery and its circumflex branches lie about lh inches below Poupart's ligament, but it is frequently i an inch higher or lower. The common femoral is separated from the capsule of the hip-joint by the psoas muscle; the femoral vein lies close to its inner side, and the anterior crural nerve i an inch to its outer side, on the psoas muscle. Branches of the sciatic and obturator arteries also enter the thigh and re- quire to be secured. The nerves divided are : the external, middle and internal cutaneous, the internal saphenous, the deep muscular branches of the anterior crural, the obturator, the great and small sciatic. The muscles divided are : the sartorius, quadriceps extensor cruris, adductors magnus and longus, ^ gracilis, and hamstrings. The capsule of the joint is divided, the head of the femur thrust from its socket, and the liga- mentum teres cut. The attachments of the follow- ing structures to the upper third of the femur have to be separated : the gluteus maximus, medius, minimus, pyriformis, gemelli, obturator internus and externus, quadratus femoris, ad- ductor magnus, brevis, pectineus, psoas and ilia- cus, with the capsular ligament. CHAPTER XXII THE THIGH Under the term " the thigh " it will be convenient to describe that part of the lower limb that ex- tends between the regions just described and the districts of the knee and popliteal space. ^ Surface anatomy. — In muscular subjects the outline of the thigh is irregular, but in the less muscularly developed, who are provided with a good share of subcutaneous fat, the limb, in this section of it, is more or less evenly rounded. The prominence of the rectus muscle is noticeable on the front of the thigh, especially when the muscle is in action. To the inner side of this structure, and conspicuous along the lower half of the thigh, is the eminence formed by the vastus internus. The mass to the outer side of the rectus is com- posed of the external vastus muscle, and occupies the greater part of the limb in this region, being, however, more conspicuous below. Running down the anterior and inner aspect of the thigh, from the apex of Scarpa's triangle, is a depression which indicates the interval be- tween the quadriceps muscle and the adductors. Along this groove the sartorius lies. Over the surface of the vastus externus a longitudinal de- pression is often to be observed, formed by the pressure exercised by the superimposed ilio-tibial band of the fascia lata. The hamstring muscles cannot usually be distinguished the one from the other above the popliteal space, nor is their 540 Chap. XXII] THE THIGH 541 separation from the adductors indicated. The separation, however, between them and the vastus externus is distinct, and corresponds to the posi- tion of the external intermuscular septum. The line of the femoral vessels has already been given (p. 5J2). The long saphenous vein follows in the thigh the course of the sartorius muscle, and may be represented on the surface by a line drawn from the region of the saphenous opening (p. 512) to the posterior border of the sartorius muscle at the level of the inner condyle of the femur. The long saphenous nerve follows the course of the femoral artery, lying first to the outer side of that vessel and then gradually crossing it. In the lower fourth of the thigh the nerve passes under cover of the sartorius muscle to the inner side of the knee, and is accompanied by the superficial branch of the anastomotic artery. A line drawn down the back of the limb from a point midway between the great trochanter and tuber ischii to the middle of the ham will correspond to the great sciatic nerve and one of its continuations, the internal popliteal (see p. 504). The great trunk usually bifurcates a little below the middle of the thigh. The skin of the thigh is coarse on the outer side of the limb, but internally it is thin and fine, and is apt to be readily excoriated by ill-applied bandages or splints. It is but loosely attached to the subjacent parts, a circumstance that greatly favours the performance of circular amputations in this region. At one place, however, it is a little more adherent, viz. along the groove that separates the vastus externus from the hamstring muscles, and that corresponds to the outer inter- muscular septum. The laxity of the subcutaneous tissue favours extensive extravasations beneath the skin, and permits of large flaps of integu- ment being torn up in cases of injury to this part of the extremity. The fascia lata invests the limb at all parts like a tightly fitting sleeve. It is thickest at its 542 THE LOWER EXTREMITY LChap. outer side, where it forms the dense ilio-tibial band. It is thinnest at the upper and inner as- pect of the thigh, where it covers the adductor muscles. It increases considerably in strength as it approaches the front of the knee, and attaches itself to the tibia and lateral margins of the patella. This fascia resists, especially at its outer part, the growth of tumours and abscesses, and limits deep extravasations of blood. It has occa- sionally been ruptured in part by violence, and through the rent so formed the subjacent muscle has bulged, forming what is known as a hernia of the muscle. This condition has been met with in the case of the quadriceps muscle, and also of the adductor longus. Such " hernise " are probably associated with some rupture of the fibres of the muscles implicated. Two deep processes of the fascia are attached # to the femur, and form the outer and inner intermuscular septa. The outer septum separates the vastus externus from the biceps, and the inner the vastus internus from the adductors. ^ Together with the fascia lata, these septa divide the thigh into two apo- neurotic spaces, which can be displayed ' in a transverse section t of the limb. These divisions, however, are of little surgical moment, and the inner septum is often so thin and feeble that it could have but little effect in directing the course of an abscess. In circular amputations of the thigh the muscles are apt to retract unevenly, since some are attached to the femoral shaft while others are free. The muscles so attached are the ad- ductors, vasti, and crureus, while the free mus- cles are the sartorius, rectus, hamstrings, and gracilis. In spite pi its great strength the tendon of the quadriceps may be ruptured by muscular violence. A good example of such an accident is recorded by Mr. Bryant (Med. Times and Gaz., 1878). A man aged 42 stumbled and fell down a pit 10 feet deep. On examination the tendon was XXII] FEMORAL ARTERY 543 found to be torn across, and the gap above the patella produced by the # rupture occupied no less extent than the lower third of the thigh. A some- what more remarkable accident is reported to have happened to the sartorius muscle. This muscle, just before its insertion into the tibia, gives off an aponeurotic expansion from its anterior bor- der to the capsule of the knee-joint. In the case alluded to (Lancet, 1873), this expansion is said to have been ruptured, and the muscle itself to have been found dislocated backwards in con- sequence. The accident befell a man aged 40, who was squatting, in the position assumed by tailors, upon the floor of a wagon, when his com- panion tripped over him and fell across his bent knees. Something was felt to have given way near the ham, and on examination the above lesion was diagnosed. The femoral artery may be ligatured at any part of its course in the thigh, and the com- paratively superficial position of the vessel ren- ders it very liable to be injured. In the middle third of the thigh it lies beneath the sartorius in Hunter's canal. The thigh affords many instances of the remarkable way in which isolated branches of a main artery are often alone damaged. Thus, Langier relates the case of a man-cook, who, in running round a table, struck the upper and outer side of his thigh against the corner of it. This led to a subcutaneous rupture of the external circumflex artery. Unfortunately the extravasa- tion was cut into, and the patient, after being subjected to many modes of treatment, died from the effects of repeated haemorrhage. Dr. Butcher (Dub. Journ. Med. Sci., 1874)^ gives the case of a man who was stabbed in the thigh over the femoral vessels during a scuffle. Profuse bleeding fol- lowed, and it was found that the only vessel wounded was the internal circumflex artery, just at its point of origin from the profunda. The case was treated promptly, and the man did well. 544 THE LOWER EXTREMITY LChap. Fractures of the femur. — The shaft of the femur may be broken at any part, but the lesion is most common at the middle third of the bone, and least frequent at its upper third. If broken by direct violence the fracture is usually trans- verse, and if by indirect violence it is usually oblique. The probability of a fracture being due to direct violence diminishes in the bone from below upwards, while the probability of a lesion from indirect violence increases in the same direc- tion. Thus it happens that the fractures of the upper third of the bone are usually oblique, while those of the lower third are more commonly trans- verse. In the middle third the numbers of the transverse and oblique fractures are more nearly balanced. The femur has often been broken by muscular violence, but it is doubtful if this has ever occurred in other than a diseased bone. In many of these cases the amount of force that breaks the bone is most insignificant. Thus, Vallin reports the case of a girl aged 18, de- scribed as robust, who broke the femur about its middle while in the act of mounting a table for the purpose of undergoing a vaginal examination. In oblique fractures in the upper third of the bone the line of fracture usually runs downwards and inwards, while in oblique fractures of the middle third the direction is more commonly downwards and forwards, with a slight lateral inclination that is sometimes inwards and sometimes out- wards. Fractures of the lower third of the bone are discussed in connexion with the region of the knee (Chap, xxiii.). With regard to fractures of the upper and middle thirds, the displacements of the fragments depend greatly upon the obliquity of the fracture. As a rule the lower fragment is drawn up behind the upper one by the hamstrings, aided by the rectus, gracilis^ sartorius, tensor vaginae, arid adductors, and is carried a little to its inner side under the influence of the last-named muscles. The lower end of the upper fragment usually XXII] FRACTURES OF FEMUR 545 projects forwards and a little backwards. This is produced by the agency of the lower fragment, which tilts the upper piece of bone in the direction named. In the fracture of the upper third of the shaft the projection forwards of the upper frag- ment is aided by the ilio-psoas muscle. Thus the deformity produced in fractures of the femoral shaft is usually angular in character. The ever- sion of the foot noted in fractures of the femur is due to the weight of the limb, which causes the helpless member to roll out, aided probably by the action of the external rotator muscles. Certain spiral fractures (helicoidal fractures of Leriche) may be produced in the lower part of the shaft as the result of torsion. M. Fere finds by experiment that if the limb be carried forwards in front of the opposite knee, and the foot rotated outwards, a spiral fracture can be produced at the junction of the lower and middle thirds of the femur. A like fracture at the same level, but with the direction of the spiral reversed, can be produced by carrying the limb outwards and then rotating it inwards. Shortening of the limb after fracture.— It is doubtful if a fracture of the shaft of the femur can, after any treatment, become united without some shortening resulting, save in a few exceptional cases. It is important, in connexion with this subject, to remember that the lower limbs may be normally of unequal length. Dr. Wight, of Brooklyn, has fully investigated this matter, and arrived at the following conclu- sions : (1) The greater number of normal lower limbs are of unequal length ; (2) the left limb is often longer than the right; (3) the average in- equality of normal lower limbs is probably about J of an inch; (4) the average amount of shortening after a fracture of the femur that has been well treated is about f of an inch ; (5) in about one case in ten or eleven the two limbs will be found to be of equal length after the union of the fracture ; (6) one limb can never be a certain standard of s 546 THE LOWER EXTREMITY [Chap length for the opposite limb. Dr. Garson, as a result of the careful examination of some seventy skeletons, states that both the lower limbs are of equal length in only about 10 per cent, of all cases. He also found that the femur was more frequently the seat of variation than the tibia. ,a 4 Fig. 110. — Transverse section through the middle of the thigh. (Braune. ) a, Rectus femoris ; b, vastus externus ; c, crureus ; d, vastus internus ; e, short head of biceps ;/, long head of biceps ; g, semitendinosus ; h, semimembranosus ; i, adductor magnus ;j, gracilis ; A, adductor longus ; I, sartorius. 1, femoral artery ; 2, great sciatic nerve ; 3, great saphenous vein ; 4, middle cutaneous nerve ; 5, external cutaneous nerve ; 6, perforating branches from profunda ; 7, small sciatic nerve. Amputation of the thigh.— As already men- tioned, the unequal contraction of the muscles renders a circular amputation unsuitable for the thigh. Hence the operation preferred is one in which a large flap is formed from the tissues in front of the thigh, and a shorter flap from the structures on the posterior aspect. The various XXII] AMPUTATION OF THIGH 547 structures which are involved and the relation- ship of the one to the other are best understood by examining a section of the thigh, such as is shown in Fig. 110. The parts cut are the following : the quadriceps, sartorius, gracilis, long and great adductors, and the three hamstring muscles; the superficial and deep femoral vessels, the descend- ing branches of the external circumflex artery, the lower perforating vessels, and the long saphenous vein ; the main branches of the anterior crural nerve (middle cutaneous, internal cutaneous, and muscular, together with the long saphenous nerve), the anterior branch of the external cutaneous nerve, the obturator, and the great and small sciatic nerves. CHAPTER XXIII THE REGION OF THE KNEE In this chapter will be considered the articulation of the knee, the soft parts about the joint, the popliteal space, the lower end of the femur, the patella, and the upper ends of the tibia and fibula. Surface anatomy. — In the front of the knee the patella can be distinctly felt and seen. Its inner border is a little more prominent than the outer. When the limb lies in the extended pos- ture, with the quadriceps relaxed, the patella can be moved to and fro, and appears to be but loosely attached. When the quadriceps is contracted the bone is drawn upwards, and becomes firmly fixed against the femur. In flexion of the joint the patella sinks into the hollow between the tibia and the intercondyloid notch, and is very firmly fixed. In this position some part of the trochlear surface of the femur can be made out above the patella. On each side of the knee-cap a hollow exists which may be completely filled up with fat in the obese. When the limb lies in the extended posture the ligamentum patellae is not to be very distinctly made out. It becomes a little more conspicuous in the flexed position, and is most prominent when the quadriceps muscle is vigorously contracted. The subpatellar pad of fat bulges outwards on each side of the ligament and may be mistaken by the inexperienced for fluid in the joint. On the inner side of the knee the following parts can be felt from above downwards (Fig. Ill) : the 548 Chap. XXIII] THE KNEE 549 tubercle for the adductor magnus, and the tendon of insertion of that muscle; the inner condyle of the femur, which is very prominent, and forms the chief part of the rounded eminence on this aspect of the joint; and below this the inner tuberosity of the tibia. Between the two latter processes of bone, the interarticular line and Semitend. Poplit. Art. Prepatel. Bursa Synov. Memb. _J, Adduct. Tub. \\ \ Sartorius Interart. Cartil. Semimemb. Bursa SUBSEMITEND. BURSA Post. Tib. Art Ant. Tib. Art. Fig. 111. — Surface anatomy of the inner aspect of the knee-joint. semilunar cartilage are easily felt (Fig. 111). On the outer side of the joint is the external condyle of the femur, which is much less conspicuous than its fellow of the opposite side, and below it is the corresponding tuberosity of the tibia, forming a marked prominence. Immediately in front of the biceps tendon the upper part of the external lateral ligament can be felt when the joint is a little flexed. Between the tendon and the patella, 550 THE LOWER EXTREMITY [Chap. the lower part of the ilio-tibial process of the fascia lata can be detected as a prominent rounded band, descending to the external tuberosity of the tibia. It is most distinct when the knee-joint is forcibly extended by muscular action, and often stands out conspicuously beneath the skin. The tubercle of the tibia and the head of the fibula are both readily felt, and are nearly on the same level. The popliteal space only appears as a hollow when the knee is bent. In the extended limb the hollow is replaced by an evenly rounded eminence. The crease in the skin that passes transversely across the ham is some way above the line of the knee-joint. On the outer side of the space the biceps tendon can be very readily felt, especially when the muscle is in action. Just behind it, and along its inner border, lies the peroneal nerve. It can be rolled under the finger as it crosses the head of the fibula to pass beneath the peroneus longus muscle. On the inner side of the ham three tendons can be felt. Nearest to the middle of the space is the long, prominent tendon of the semitendinosus. Internal to it is the larger and less distinct semimembranosus tendon, and still more to the inner side the gracilis may be made out. The popliteal vessels enter the ham obliquely at its upper and inner part, and under cover of the semimembranosus muscle. The outer border of this muscle is. the guide to the upper portion of the artery (Fig. 111). The vessels in their descent reach a point behind the middle of the knee-joint, and then pass vertically downwards. The termination of the popliteal artery is on a level with the lower part of the tubercle of the tibia. When the limb is flexed, the pulsations of the artery can be felt and the vessel compressed against the femur a little below its point of entry into the popliteal space. The upper articular arteries run trans- versely inwards and outwards just above the femoral condyles. The lower articular arteries XXIIIj THE KNEE 651 are also placed transversely, the inner vessels running just below the internal tuberosity of the tibia, and the outer just above the head of the fibula. The deep branch of the anastomotica magna descends to the inner condyle of the femur in the substance of the vastus internus, and along the front of the adductor magnus tendon. The internal saphenous vein passes up along the back part of the internal condyle of the femur, and then follows the sartorius muscle to the thigh. It is just below the interarticular line that the long saphenous nerve usually joins the vein. The short saphenous vein follows the middle line of the calf just below the ham, and pierces the deep fascia at the lower part of the popliteal space. This vessel is much less conspicuous than is the long saphenous vein, and is, indeed, not often to be seen unless varicose. The internal popliteal nerve descends in the middle line, and continues the line that marks the course of the great sciatic trunk. In their normal condition the popliteal glands are not to be felt. The limits of the synovial membrane of the knee-joint, and the position of the various bursae about this articulation, will be dealt with in some of the subsequent paragraphs. Front of the knee. — The skin over the front of the knee is dense and very movable. This mobility affords considerable protection to the knee-joint, especially in stabs with bluntish in- struments, and in any injury where the gliding movement of the skin may direct the violence away from the articulation. The comparative looseness of the integument is sometimes utilized t in the operation of removing so-called " loose cartilages " from the knee-joint. It permits the incision into the joint to be very indirect, and, the skin being dragged out of place during the operation, it follows that, when the procedure is complete, the surface wound and that in the knee capsule no longer correspond. In flexion, the skin is drawn 552 THE LOWER EXTREMITY [Chap. tightly over the patella, and, as is the case else- where, where the integument lies more or less directly upon the bone, a contusion over the knee- cap may produce a lesion precisely like an in- cised wound. In the Lancet for 1877 is recorded the case of a very stout woman, aged 57, who, stumbling on a hard road, fell upon her bent knee. The skin was burst across the front of the knee, and a wound was produced that was 7 inches in length, and was as cleanly cut as if made by a scalpel. There is but little subcutaneous fat in front of the articulation, and thus it happens that in am- putations through the knee-joint the anterior flap is very thin, and is composed of little other than the simple integument. As blisters, and various forms of counter- irritant, are often applied to the front of the knee in cases of disease, it may be well to take note of the blood supply of this part, and of the relations between the surface vessels and nerves and those of the joint. The vessels that give branches to the front of the knee, and are concerned in the supply of the part to which blisters are usually applied, are the anastomotic, the four articular branches of the popliteal, and the anterior tibial recurrent. Now, of these arteries, and especially of the anastomotica magna and superior articular, it may be said that, shortly after their origin, they divide into two branches, or two sets of branches, one going to the surface and the other to the articulation of the knee and deeper parts about it. It may be supposed, therefore, that, in applying & counter-irritant in front of the knee for the relief of a joint affection, a greatly in- creased quantity of blood is drawn into the super- ficial divisions of the above-named vessels, and less blood is thereby left to flow by their deeper branches to the seat of disease. The skin over the front of the knee, the anterior parts of the joint, and the quadriceps are supplied from the third and XXIII] FRONT OF THE KNEE 553 fourth lumbar segments through branches of the anterior crural and obturator nerves. The superficial lymphatics in the region of the knee lie for the most part on the inner aspect of the joint, and follow the course of the long saphenous vein. Ulcers, and other inflammatory affections of the skin over the articulation, are more apt to be associated with lymphangitis and with enlargement of the inguinal glands when situate on the inner aspect of the joint than when placed in front or to the outer side of it. The bursas over the front of the knee are : (1) The patellar bursa, a large sac placed in front of the patella and upper part of the patellar liga- ment, separating those structures from the skin (Fig, 111). It is frequently divided by septa into superficial and deep compartments. It is very often found enlarged in those who kneel much — in housemaids, stonemasons, > religieuses, etc. The parts about are well supplied with nerves, and hence much pain is usually associated with acute inflammation of this sac. It is in close contact with the patella, and, in one case reported by Erichsen, suppuration of the bursa led to caries of that bone (Figs. 112, 113, and 117). (2) There is a bursa between the patellar ligament and the tubercle of the tibia (Fig. 113). When inflamed, it causes more pain than is observed in affections of the previous bursa, since it is firmly compressed between two rigid structures, the ligament and the bone. It is separated from the synovial cavity by the pad of fat that lies behind the patella. (3) The bursa between the quadriceps tendon and the femur will be considered in connexion with the synovial cavity. Popliteal space.— The skin over the space is not so movable as is that over the front of the knee. When destroyed by injury, by burns, or by extensive ulceration, the contraction of the resulting cicatrix may lead to a rigidly bent knee. The skin in this place has also been rup- tured by forcible extension applied to the limb in s* 554 THE LOWER EXTREMITY [Chap. cases of contracted knee. Beneath the skin and superficial tissue is the popliteal fascia, a dense membrane that covers in the space. It is but a continuation of the fascia lata of the thigh, and is continuous below with the fascia of the leg. It passes without bony attachment over the ham- string muscles that bound the ham. This fascia limits, often in a very marked manner, the pro- gress of popliteal abscesses and growths towards the surface. Its unyielding character is a prime cause in the production of the severe pain with which such collections and tumours are often associated. The popliteal abscess, unable to reach the surface, is encouraged to extend either up into the thigh or down the leg. The ham may hold a very considerable quantity of pus. Vel- peau has seen a case where a litre (1 pint, 15 oz.) of pus was evacuated from this region in a patient who presented before the operation but an insignificant swelling in the site of the collection. Duplay records two cases of ulceration of an ab- scess into the popliteal artery, and Ollivier an instance where the abscess, unable to find a way to escape, ultimately entered the knee-joint. Pus may reach the ham from the buttock or pelvis by following the great sciatic nerve, or may extend from the thigh through the opening in the great adductor for the femoral vessels. The hamstring muscles are frequently found contracted in neglected cases of knee-joint disease, and produce* thereby more or less rigid flexion of the leg upon the thigh. Irritation from disease of the knee-joint may lead to contracture of the hamstring muscles. These muscles are sup- plied through the great sciatic nerve from the fifth lumbar segment, from which the knee-joint derives in part its nerve supply. Muscles on the flexor aspect of a bent joint undergo a permanent shortening if the position be maintained for a con- siderable space of time. Contraction of these muscles in knee-joint dis- ease tends not only to flex the knee but also to XXIII] VESSELS OP THE HAM 555 draw the tibia backwards, and produce in some cases a partial luxation. The hamstring tendons may be ruptured by violence, the tendon most frequently torn being that of the biceps. The muscles i are greatly stretched when the trunk is bent forcibly forwards at the hip-joint, the knee remaining extended. Extreme movement in this position has ruptured some of the fibres of^ this muscle. The difficulty experienced in touching the toes with the fingers while the knees are kept stiff depends upon the resistance offered by the stretched hamstrings. In tenotomy of the biceps tendon the peroneal nerve is in great risk of being wounded. It may be noted that contraction of the muscle tends to increase the distance between the tendon and the nerve, and to render the former more superficial. The peroneal nerve may be compressed by band- ages or garters applied too tightly over the head or neck of the fibula. Vessels of the ham. — The popliteal vessels are, from their depth, but seldom wounded. It must be borne in mind that the lower part of the artery may be reached from the anterior aspect of the leg by an instrument passing between the tibia and fibula. Thus, S pence reports the case of a farmer who received a wound in front of the leg 5j just below the knee, from the slipping of his knife while cutting a stick. It was dis- covered subsequently that the knife had entered the interosseous space and had wounded the pop- liteal artery at its bifurcation. It had indeed nearly severed the anterior tibial artery from the main trunk. The popliteal artery has been ruptured by ex- ternal violence, as when a wheel has passed over the region of the vessel. This artery is more fre- quently the seat of aneurysm than is any other artery in the body, save only the thoracic aorta. In 551 cases of spontaneous aneurysm, collected by Crisp, the popliteal vessel was the seat of the disease in 137 instances, the thoracic aorta having 556 THE LOWER EXTREMITY [Chap. been affected in 175 of the cases. This marked disposition to aneurysm depends upon many factors. The vessel is subjected to a great deal of movement, and often to very violent movement. Experiments upon the dead body show that the inner and middle coats of the vessel may be rup- tured by extreme flexion of the knee, and that a like rupture may in a smaller percentage of cases be brought about by forcible extension^ More- over, except when the limb is in the position of extension, the popliteal artery is, like the thoracic aorta, much curved. Then, again, the vessel breaks up into two large vessels, and it is well known that the point of bifurcation of an artery is a favourite spot for aneurysm. Lastly, the artery is supported only by the lax tissue of the popliteal space, and the support of strong muscles given elsewhere to so many large vessels is practi- cally absent. Some popliteal aneurysms have been successfully treated by flexing the knee and retain- ing the limb for some time in that position. That flexion can have a direct effect upon the lumen of the vessel is shown by the diminished pulse at the inner ankle produced by forcibly bending the leg upon the thigh. ( The artery and vein are so adherent that it is difficult to separate the two when applying a ligature to the arterial trunk. This adhesion must have been appreciated by any who have taken pains to " clean " the artery in a dissection of the ham. The popliteal vein is a remarkably substantial vessel, and has walls so dense and thick that on section they often look more like the tunics of an artery. On the ground of this peculiarity, and of its close adhesion to its companion vessel, Tillaux asserts that " it is unlike any other vein in the economy." It is worthy of note that the vein, although more superficial than the artery, is very rarely ruptured by violence. As a rule, the artery alone is torn. In a few cases < both the vessels may suffer; but I can find no instance recorded of rupture of the popliteal vein alone. XXIII] THE HAM 8Sf From the relations of the artery to the vein and nerve it will be understood that a popliteal aneurysm may soon lead to oedema of the leg and to nerve symptoms depending upon pressure on the internal popliteal trunk. It has more than once also made its way into the knee-joint, with the posterior ligament of which the artery is in such close relation. The short saphenous vein lies almost in the middle line, and, not being usually apparent through the skin, may be divided in an incision made into the lower part of the popliteal space. The lymphatic glands in the ham are from four to five in number and are deeply placed about the great vessels. When enlarged they have been mistaken for aneurysm and other popliteal tumours. They receive the deep lymphatics of the leg. A small gland is often met with beneath the fascia, close to the point of entry of the short saphenous vein. It receives some lymphatics that follow that vessel. The bursas about the < ham are usually seven in number, four on the inner side of the space and three on the outer. Inner side. — (1) A large bursa between the internal condyle of the femur and the inner head of the gastrocnemius and the semimembranosus (Fig. 111). This is the largest bursa in the space, and after adult life it usually communicates with the joint. It is, of all the bursas in this region, the one most often enlarged, and when affected may attain great size. In one reported case the sac measured 5 by 3^ inches. In the extended position of the limb the enlarged bursa feels firm and resistant, but on flexion it becomes flaccid and can often be made entirely to disappear. Probably the slit-like communication between the bursa and the joint is closed when the posterior ligament is tightened by extension, and is opened when it is relaxed on bending the knee. In the latter posture the contents of the bursa can be reduced into the cavity of the knee- joint, and so the tumour disappears. (2) A little m THE LOWER EXTREMITY [Chap. bursa between the semimembranosus tendon and the tuberosity of the tibia. Rather below the level of the knee there are two further bursae — (3) one beneath the insertion of the sartorius, and (4) another beneath the insertions of the gracilis and semitendinosus. Outer side. — (1) A large diverticulum of the synovial membrane of the joint between the popliteus tendon and the ex- ternal tuberosity of the tibia. This diverticulum serves the purpose of a bursa, and may open into the tibio-fibular articulation, and so bring that cavity into connexion with the knee-joint. (2) A bursa between the outer head of the gastrocnemius and the femoral condyle. It is not constant and is not connected with the articulation. (3) A bursa between the biceps tendon and the external lateral ligament. The peroneal nerve runs across this sac, a circumstance that may explain some of the pain experienced when the bursa is enlarged. It is not improbable that wounds in this region of bursse containing fluid have been mistaken for wounds of the joint, and the escaping serum for synovia. The knee-joint (Fig. 112). — This articulation is the largest in the body. It owes its great strength to the powerful ligaments that unite the two component bones, and especially to the muscles and fascise that surround it. It derives no strength from the shape of the articular surfaces, since they are merely placed in contact with one another. In spite of its frequent exposure to in- jury, dislocations at the knee are extremely rare. The lateral ligaments are comparatively feeble, are tense in extension and relaxed in flexion. The laxity of these ligaments is such that partial luxations of the tibia are possible without rup- ture of these bands, especially in cases where the joint is found slightly flexed after the accident. The crucial ligaments are very powerful, and are more or less tense in all positions of the joint. The anterior of these ligaments especially^ resists extension, forward displacement of the tibia, and XXIII] THE KNEE-JOINT 559 rotation inwards of the leg. The posterior band resists flexion and displacement backwards of the tibia. In the movement of extension the tibia slides a little forwards and is rotated a little out- wards. In flexion that bone glides backwards and rolls a little inwards. Extension generally is Fig. 112. — Vertical section of normal knee-joint. (Braune.) a, Quadriceps ; &, semimembranosus ; c, gastrocnemius ; d, posterior crucial ligament ; e, ligamentum patellae ;/, bursa between quad- riceps and femur. limited by the crucial and posterior ligaments; flexion by the ligamentum patellae and anterior part of the capsule, in addition to the crucial ligaments. Rotation is possible only in the flexed position. The thinnest part of the posterior liga- ment is the portion below the oblique fibres de- rived from the semimembranosus. If pus should find its way from the joint into the ham, it 560 THE LOWER EXTREMITY [Chap. will probably escape through this part of the ligament. In the contracted knee associated with fibrous ankylosis, the chief contraction, so far as the joint tissues are concerned, is in the posterior ligament, in the lateral ligaments, and in the fibrous and fatty tissue between the former liga- ment and the posterior crucial band. The synovial membrane of the knee-joint ex- tends upwards as a large cul-de-sac above the patella and beneath the extensor tendon. This cul-de-sac reaches a point an inch or more above the upper margin of the trochlear surface on the femur, and is rendered very distinct when the joint is distended with fluid (Fig. 113). When the knee is bent the cul-de-sac is drawn down, and therefore this position of the limb is advised when operations are about to be performed upon the lower end of the femur. Above the synovial pouch is a bursa that separates the quadriceps tendon from the femur, and is usually over an inch in its vertical measurement (Fig. 113). From the examination of two hundred and sixty knee- joints in both infants and adults, Schwartz found that this bursa communicated with the synovial cavity in seven cases out of ten in young children, and in eight cases out of ten in adults. It will thus be seen that when this communica- tion exists, a stab over the femur, about 2 inches above the trochlear surface of the bone, or about the same distance above the top of the patella, when the limb is extended, will practically open the knee-joint. Cases are reported of extravasation of blood into this bursa that, although at first limited to the sac, have, on rough handling, extended into the knee-joint^— a circumstance leading to the sup- position that in some cases the orifice of communi- cation may be very small. The crucial ligaments, although more or less completely invested by the synovial membrane, are yet entirely outside the synovial cavity, and XXIII] THE KNEE-JOINT 561 divide the cavity behind into an outer and an inner condylar recess. The posterior ligament is con- tinuous with the posterior part of the capsule. Fig. 113. — Vertical section of knee-joint distended with fluid. (Braune.) a, Vastus externus ; b, crureus ; c, shoit head, and d, long head, of biceps ; e, plantaris ; /, gastrocnemius ; g, popliteus ; h, soleus ; t, tibialis posticus ; j, bursa patella) : k, ligamentum patellae ; I, ligamentum mucosum ; m, anterior crucial ligament : w, exter- nal semilunar cartilage. 1, external popliteal nerve ; 2, popliteal artery. The upper third of the patellar ligament is in relation to the synovial membrane, from which, however, it is separated by a pad of fat. The lower two-thirds of the ligament are in rela- tion to the bursa and fatty tissue that intervene 562 THE LOWER EXTREMITY [Chap. between the band and the tibia. A knife passed horizontally backwards at the apex of the patella would, when the limb is extended, just miss the joint line between the femur and tibia, and would hit the latter bone (Fig. 112). If, however, there be any effusion in the joint, or the limb be a little flexed, a knife so introduced would pass between the two bones (Fig. 113). Fringes of the synovial membrane (the alar ligaments) fill the intervals between the articular surfaces of the patella and femur. Villous processes may grow out from them, become detached, and form loose bodies in the joint. That such processes should undergo chondrification and form cartilaginous bodies is not^ surprising, seeing that the synovial lining is derived from the same tissue as forms the articular surfaces of the bones and is in reality merely a finely spread layer of cartilage covering a fibrous membrane. Joint disease. — Owing to its superficial posi- tion the knee-joint is the articulation that is most frequently the seat of inflammation due to injury and exposure to cold. When distended with fluid, the effusion soon shows itself above and at the sides of the patella, by bulging for- ward the synovial sac, which is here more nearly in relation to the surface than it is elsewhere. Fluctuation is soon to be detected, and the patella, being pushed away from the femur, is said to " float v upon the distending fluid (Fig. 113). The inflamed knee-joint, if left to itself, almost invariably assumes the flexed position. This may be explained upon three hypotheses, and it is probable that each of the three reputed factors takes part in producing this position in cases of disease. 1. The capacity of the joint is increased on flexion. The pain of acute synovitis is due mainly to the increasing distension of the joint with fluid, and it is natural that the patient should in- stinctively place the limb in the position in which the joint will hold the greatest amount of fluid, XXIII] SEMILUNAR CARTILAGES 563 and in which the interarticular tension is reduced to a minimum. Braune found that the maximum capacity was reached when the knee was flexed 25°, and the minimum on complete flexion. 2. By flexing the limb, the more powerful ligaments (such as the ligamentum posticum, the posterior crucial and lateral ligaments) are re- laxed, while the ligaments rendered tense by the position are the patellar and the anterior part of the capsular, the latter of which is but a yielding membrane. 3. The sensory nerves of the joint being dis- turbed, contraction of muscles may be anticipated from reflex action, and of the muscles so excited the flexors may be expected to have the advantage, as being the more powerful and the more favour- ably placed for acting upon the articulation. Dislocation of the semilunar cartilages. — One or other of these cartilages may be displaced from its attachments to the tibia, and become nipped or locked between that bone and the femur. The result is a sudden pain in the limb, associated with a fixing of the knee in a flexed position. The accident is usually brought about by a twist given to the leg when the knee-joint is more or less bent. In 200 cases of internal derangement of the knee-joint, Bennett found that the internal cartilage was affected in 155 cases and the external in only 45. The left knee was the seat of derange- ment nearly three times as often as the right, and the lesion occurred nine times more frequently in men than in women. In every one of twelve cases operated on by Marsh, the anterior extremity of the internal semilunar cartilage was found bruised and torn from its tibial attachment. To understand the liability to injury of the anterior part of the internal semilunar cartilage, it is necessary to examine the manner in which it is maintained in position, the movements which it undergoes, and the strains to which it is sub- jected in active athletes — for it is amongst them that displacements most frequently occur. In the 5G4 THE LOWER EXTREMITY | Chap. extended position of the knee, displacement is impossible, for the cartilages are immovably fixed by the coaptation of the articular surfaces, brought about by the tension of the ligaments and tonus of the muscles surrounding the joint. When the joint is partly flexed the internal cartilage is : fixed (1) by its anterior horn attached to the tibia, above and behind the attachment of the liga- mentum patellae and outside the joint cavity (Fig. 114) ; (2) by the transverse ligament to the anterior part of the external cartilage (Fig. 114); (3) by Transverse Lie, COROrtARy Lie External Semi li A/it.Cruc Popliteus. Ext.Lat.Lii Biceps qawe/itum Patellae Am. AIor/i ■COROrtARy Liq. /iteraialSe/iilu/iar Cartilage /iTERrtAL Lateral Liq. Post. Crucial Lie .Liq. Fig. 114. — Illustrating the fixation and movements of the semilunar cartilages. The position of the internal semilunar cartilage when the tibia is rotated outwards or femur inwards, is shown in red. the coronary ligament to the capsule of the joint and internal lateral ligament : the anterior fibres of this ligament are the longest (Fig. 114). As the joint is flexed the cartilages, especially the in- ternal, glide backwards; if in this position the biceps brings about a sudden rotation outwards of the tibia, the anterior horn is carried forwards and outwards with that bone, while the posterior is firmly fixed to the internal condyle of the femur by the internal lateral ligament, and thus a severe strain is thrown on the anterior part of the internal cartilage, which is brought into the position shown in Fig. 114. Its weakest point XXIII] GENU VALGUM 565 is in the thin inner crescentic margin of its an- terior third, and it is here that partial rupture usually occurs. The intense pain is due to the rupture and to the fact that the strain wedges the cartilage between the tibia and femur, thus forcing them apart and causing an instant and severe hyperextension of the unyielding liga- ments of the joint. The external cartilage is smaller than the internal, is rounder, is more movable, and possibly on these accounts is less likely to be "nipped" between the bones. It is attached in part to the femur through the pos- terior crucial ligament and is grooved f by the tendon of the popliteus, two factors which add to its security (Fig. 114). Genu valgum, or knock=knee. — The appearances produced by this affection are familiar. When a person stands erect with the feet together, the tibisB are practically vertical, and the femora meet them at a certain angle. The degree of this angle depends, in normal subjects, to a great extent upon the relative width of the pelvis. In genu valgum the tibiae cease to be vertical in the erect position ; their lower ends deviate more and more from the middle line, until the distance be- tween the two malleoli becomes considerable when the individual stands upright and when he is not concealing any of the deformity by rotating the limb. The^ progress of the genu valgum may be di- vided into three stages. In the first stage there is a yielding or elongation of the internal lateral ligament, and of the fascial structures on the inner side of the joint. That the yielding of this ligament alone will permit of a lateral movement at the articulation being accomplished is illus- trated by cases of sprains of the knee, where the ligament has been torn, and where much lateral bending has been in consequence permitted. It is probable that the crucial ligaments yield also a little, and it is upon the posterior band at- tached to the internal condyle that the strain 566 THE LOWEE EXTREMITY [Chap. possibly first comes. In the second stage there is a contraction of the tissues on the outer side of the joint that have been relaxed by the new posi- tion of the limb These structures are the ilio- tibial band of the fascia lata, the external lateral ligament, and the biceps tendon. This contrac- tion tends to give permanency to the deformity. In the third stage the bones become changed. On the outer side of the joint the external con- dyle and the outer tuberosity of the tibia are pressed together, and through these bones the Fig. 115. — A, Normal femur ; B, femur in an advanced state of knock-knee, showing the enlargement of the internal condyle. The dotted line in each case represents the line of the epiphysis. greater part of the weight of the body will be transmitted. As a result of the continual pres- sure the parts waste a little, and by their atrophy contribute not only to the extent of the deformity but also to its permanency. On the inner side the internal condyle tends to become separated from the tibia, and an interval to develop be- tween the two bones as the deformity advances. This interval is prevented from actually existing by the development of the condyle, which enlarges, and so still maintains its contact with the tibia. Mikulicz has pointed out that " the alteration in length on the inner side of the femur arises not XXIII] FKACTURES OF PATELLA 567 Cb^r from alteration of the epiphysis, but is confined to the lowest part of the diaphysis." This state- ment also holds true for the tibia. This is shown in the diagram (Fig. 115), where it will be seen that the enlargement of the internal condyle is due almost entirely to increased growth in the diaphysis. The increased growth does not affect the antero-posterior diameter of the condyles. Hence, when the knee is flexed, all trace of the deformity disappears. Fractures of the patella. — This bone is more often broken by muscular violence than is any other in the body. Although the patella may be fractured by both mus- cular and direct violence, it would appear that the former is the agent that most often produces the lesion. Thus, in 127 cases of simple transverse frac- ture collected by Hamilton, he considers that muscular action was the cause of the injury in 106 instances. The form of fracture due to muscular violence is very uniform. It is nearly al- ways transverse, simple, and through the centre of the bone, or just above that point or just below it. Fractures due to direct violence may present the same appearance, but they are more often starred, or oblique, or even longitudinal. Experiments upon the cadaver show that a simple transverse frac- ture about the centre of the bone cannot be pro- duced with any degree of certainty by a direct blow. The position of the knee that most favours fracture by muscular action is that of flexion. When the knee is bent, the patella rests upon the femoral condyles along its transverse axis only. Nearly the whole of its upper half is unsupported Fig. 116. — Diagram to show mechanism of fracture of the patella by muscular action. a, Line of action of quadri- ceps muscle ; &, femur ; c, tibia. 568 THE LOWER EXTREMITY [Chap. behind, and the extensor muscle acts in a line nearly at right angles to the vertical axis of the bone. Thus, by violent contraction of the quadri- ceps, the patella may be snapped across the condyle as a stick is snapped across the knee # (Fig. 116). As the fracture usually causes the patient to fall, it has been supposed that the contact with the ground, rather than any previous muscular action, may have caused the lesion. But, as Hamilton has pointed out, if a person falls upon the bent knee when the limb also is flexed upon the trunk, the part that comes in contact with the ground is not the patella, but the tubercle of the tibia. In the great majority of cases the lesion not only involves the bone but also the cartilage and fibrous structures that cover it respectively be- hind and in front; the synovial membrane also is torn, arid the patella bursa opened up. Thus the synovial contents may come in actual contact with the skin. " It is anatomically possible, if the fracture involve only the lower and non- articular portion of the patella, and if the amount of the separation of fragments is slight, that the fatty tissue behind the apex of the patella, over which the synovial membrane is reflected may save the latter from injury" (Sir Henry Morris). In all cases where there is much separation of the fragments, the fibrous expansion attached to either side of the patella must be torn through. Indeed, none but a slight separation of the parts is possible until that expansion is ruptured. Braune has demonstrated this by experiment, by sawing through the patella without damage to the lateral ligamentous structures, and noting that but trifling separation of the fragments was possible until these structures had been divided. In stellate fractures, due to direct violence, these fibrous expansions from the extensor tendon may be uninjured, and no separation of any magni- tude be permitted between the portions of the broken bone. XXTTT1 FKACTUEES OF PATELLA 5G9 The patella is more readily broken by muscular violence than is either the extensor tendon or the ligamentum patellae. In the flexed position it will be seen (Fig. 116) that the bone is placed at a considerable disadvantage when compared with the two other structures. Richet reports a case where violent contraction of the quadriceps caused the tubercle of the tibia to be torn away from the bone without any other lesion of the parts immediately con- cerned being produced. The patella may be congen it- ally absent. It is developed in the tendon of the quadriceps, remaining carti- laginous until the end of the second year. Its sesamoid nature is seen in the tendency to unite by fibrous rather than by bony union after frac- ture. It receives its blood supply from nearly all the arteries round the knee- joint. Dislocation of the patella. —This bone may be dislocated out- wards or inwards, or turned upon its edge so that its anterior and posterior surfaces are placed laterally. The luxation outwards is by far the most common. This depends upon the Fig. 117. — Transverse section of left knee-joint through the centre of the patella. (Brmtne.) a, Bursa patellae ; &, internal lateral liga- ment and inner condyle ; c, external lateral ligament and outer condyle ; d, biceps ; e, semimembranosus ; /, semi tend inosus ; g, gracilis tendon ; It, sartorius. 1, internal popliteal nerve ; 2, external popliteal nerve ; 3, internal saphenous vein. 570 THE LOWER EXTREMITY [Chap. fact that the quadriceps, the patella, and the ligamentum patellae do not, when the muscle is contracted, follow the lines of the femur and tibia. They are more nearly in a straight line, that passes to the outer side of the angle formed by the femur with the leg at the knee- joint. Muscular contraction, therefore, tends to draw the knee-cap outwards, a tendency that is in all normal circumstances corrected by the in- creased prominence of the external condyle. The vastus externus also is said to be more powerful than the internus. The tensor vaginae femoris has an ^ attachment to the patella through the ilio- tibial band. By the sudden action of this muscle a patient of Mr. Rigby's was able to produce a voluntary outward dislocation of the patella. Dislocations usually occur in the extended posi- tion of the joint, and are commonly due to mus- cular action. In the dislocation of the patella upon its edge, the inner border of the bone usually projects forwards, while the outer is placed between the condyles. But little is known as to the mechanism of this dislocation. In dislocations of the knee, which are very rare, the tibia may be displaced outwards, in- wards, forwards, or backwards. The two lateral luxations appear to be more common than the antero-posterior. The former are nearly always partial, the latter usually complete. Consider- able violence is required to produce these luxa- tions, owing to the great strength of the liga- ments and muscles and the great width of the bones involved. Direct violence to the tibia or femur, associated often with a twisting of the former bone, is the common cause of the lesion. It is probable that in all luxations of the knee the crucial ligaments are torn. The lateral liga- ments also are usually ruptured, but in the partial luxations they may be sometimes found to be intact. The tendinous expansion of the vasti in front of the knee seldom escapes some lacera- XXIII] LOWER END OP FEMUR 571 tion, even in the partial dislocations. The pro- jection of the spine of the tibia between the femoral condyles offers an obstruction to lateral luxation. Dr. F. S. Mackenzie found by experiment on the dead body that division of the crucial ligaments did not materially influence the force necessary to produce a dislocation at the knee-joint. He found, too, that in seven out of eight experiments, dislocation was produced and not fracture— whereas in life fracture is by far the commoner result. He concludes, therefore, that the strength of the joint depends on the surrounding muscles rather than on the surrounding ligaments. The popliteal vessels and nerves are much compressed, and appear to be more severely injured by the femur in the forward dislocation than by the tibia in the backward displacement. Lower end of the femur. — The condylar part of the femur is composed almost wholly of cancellous bone, with but a slight layer of com- pact tissue. It is so spongy that it may be pierced by a bullet, as pointed out by Legouest, without any splintering of the bone being pro- duced and without damage to the articulation. The fractures that may be met with in the lower end of the bone are the following : (1) a fracture of the shaft above the condyles; (2) a separation of the lower epiphysis ; (3) a fracture separating either the outer or inner condyle ; (4) a T-shaped fracture, i.e. a transverse fracture above the con- dyles with a vertical one between those processes. These lesions are, as a rule, due to well-localized direct violence. Fractures Nos. 1 and 4 may be produced by indirect violence, as by a fall upon the feet from a height. Sir Henry Morris states that lateral flexion, or force applied in a lateral direction, is best calculated to produce a separa- tion of the epiphysis. Hamilton reports a strange case in a man aged 21, whose outer condyle was fractured by a twist of the leg which happened while he was undressing himself to bathe. The only fracture that requires special notice in this ., 572 THE LOWEft EXTREMITY LChai place is the fracture of the shaft just above the condyles. The lesion is situated generally about 2 inches above the line of the epiphysis, and corre- sponds to the spot where the compact shaft joins the softer and more cancellous tissue of the lower end of the bone. It is near the place, also, where the femoral artery crosses the bone to reach the ham, and it has thus happened that the vessel has been wounded by splinters in this particular injury. The fracture is usually oblique, from be- hind downwards and forwards. The lower frag- ment will be drawn upwards by the same muscles that produce shortening in other fractures of the shaft (p. 544), and its sharp upper end is very apt to be pulled forcibly into the popliteal space by the gastrocnemius muscle. This latter displace- ment is difficult to remedy. If the limb be ex- tended, the fragment is only drawn the more into the ham, and it is therefore possible for the limb to appear straight and yet have the knee-joint much bent. In several cases of this injury I divided the tendo Achillis, and then placed the limb upon a straight splint, following a practice suggested by Mr. Bryant. The effect upon the position of the fragments was in each case very good (Brit. Med. Journ., 1883). The lower frag- ment of the femur may be replaced by completely flexing the leg on the thigh. (Hutchinson and Barnard.) The upper end of the tibia is sometimes the seat of fracture, although of all parts of this bone the upper third is the part least often broken. One or other of the tuberosities may be broken off, or there may be a transverse or oblique fracture of the upper end of the shaft associated with a vertical one running up into the joint be- tween the two tuberosities. Such accidents are the result, in nearly every instance, of great direct violence. Madame Lachapelle reports a case of separation of the upper epiphysis of the tibia caused by traction during parturition ; but I am not aware of any reported case of separation of XXIII1 EXCISION OF KNEE-JOINT 573 this epiphysis due to violence or under circum- stances other than this. Mr. Makins reports three cases of separation of the anterior tuber- osity in adolescents. It is usually ossified by an extension from the epiphyseal centre for the upper extremity of the tibia, but may have a separate centre (Schlatter). The spongy tissue in the head of this bone and in the lower end of the femur is, par excellence, the favourite seat for myeloid sarcoma. In excising the knee-joint through an incision commencing at the back of one condyle, and continued across the joint, above the insertion of the ligamentum patellae, to the back of the other condyle, the following structures are divided : Skin, fascia, patellar plexus of nerves (formed by the middle and internal cutaneous and the patellar branch of the long saphenous), bursa patellae, anterior part of the capsule, ligamen- tum patellae, synovial membrane, lateral and crucial ligaments, the superior and inferior ar- ticular arteries, the anastomotica magna, and the anterior tibial recurrent vessels. The incision over the inner^ condyle need not be made so far back as to divide the internal saphenous vein and nerve. In sawing the femur it is most important that the exact inclination of the joint surface of the bone be reproduced. If improperly sawn, the patient would be bow- legged or knock-kneed. The rule, therefore, is that the saw be applied parallel to the articular surface and perpendicular to the shaft. In young subjects care must be taken that the saw-cuts do not pass beyond the epiphyseal line. The upper limit of the femoral epiphysis will be represented by a horizontal line drawn across the bone at the level of the tubercle for the adductor magnus (Fig. 118). % If the whole of the trochlear surface be removed in the excision the whole of the epiphysis will have been taken away. A single nucleus appears in this epiphysis shortly before birth, and joins the shaft about the twentieth 574 THE LOWER EXTREMITY [Chap. year. The limits to the tibial epiphysis are repre- sented behind and at the sides by a horizontal line that just marks off the tuberosities. It includes, therefore, the depression for the insertion of the semimembranosus, and also the facet for the fibula. In front the epiphyseal line slopes downwards on SUBCRUREAL BURSA Joint Cavity Liq. Mucos. Subpatel. Bursa Epiphyseal Lines Fig. 118. — Epiphyseal lines in the neighbourhood of the knee-joint and their relationship to the synovial mem- brane. (After Allen Thomson.) either side to a point on the upper end of the shin, so as to enclose the whole of the tubercle of the tibia (Fig. 118). The centre joins the main bone at the twenty-first or twenty-second year. The popli- teal artery runs some risk of being wounded in excision of the joint. The vessel is separated by some little distance from the popliteal surface of XXIII] AMPUTATION THROUGH KNEE-JOINT 575 the femur (Fig. 117), but is in very close relation to the tibia, the posterior ligament alone inter- vening at the upper level of the bone. It thus happens that the risk of wounding the artery is greater when the tibia is sawn than when the lower part of the femur is being removed. Excision of the knee is, to a large extent, replaced by artHrectomy. Indeed, excision of this joint carried out in the complete manner just described must be classed as quite a rare operation. Amputation through the knee-joint.— To il- lustrate the anatomy of the part an amputa- tion by a single anterior flap may be selected. The parts involved are shown in Fig. 117. In fashioning the anterior flap (composed only of integument), and in opening the joint, the patellar plexus of nerves, the superficial branches of the plexus of arteries, the ligamentum pa- tellae, and the anterior part of the capsule will be cut. Nearer the condyles of the femur the anastomotic and the two superior articular arteries will be divided. The long saphenous vein and nerve will be divided at the inner angle of the flap. On the cut surface made by the posterior incision will be found divided the sartorius, gracilis, and semitendinosus, the semimembran- osus, both heads of the gastrocnemius, the popli- teus, plantaris, and biceps. The popliteal vessels, the sural arteries, the short saphenous vein, the internal and external popliteal nerves, the ex- ternal saphenous and the small sciatic nerves will also be found divided in the same incision. The most convenient amputation at the knee- joint is by equal lateral flaps (Stephen Smith's operation). This operation has been attended by excellent results, and in actual practice the method of amputation by a single anterior flap is but very rarely employed, CHAPTER XXIV THE LEG Surface anatomy. — The anterior border of the tibia can be felt in its entire length, forming, as it does, the prominence of the shin. It should be remembered that this border presents a some- what flexuous course, being curved outwards above and inwards below. The broad internal surface of the bone is subcutaneous, and the internal border can be followed from the tuberosity to the malleolus. The head of the fibula can be dis- tinctly made out, but the upper half of the shaft of the bone is lost beneath the mass of muscle on the outer side of the limb. The lower half of the fibular shaft can be felt, and the bone just above the malleolus becomes subcutaneous in the interval between the peroneus tertius and the two other peroneal tendons. The fibula is situated so far behind the line of the tibia that a knife thrust transversely through the leg from the inner side behind the tibia will appear in front of the fibula on the outer side (Fig. 120). Between the tibia and fibula the outline of the tibialis anticus muscle can be well defined when it is in action. To its outer side is the less conspicuous and narrower eminence formed by the extensor communis digi- torum. In well-developed limbs the groove that separates these two muscles is very distinct, and forms the best guide to the anterior tibial artery. In the lower third of the leg these muscles be- come tendinous, and between them the extensor 576 Chap. XXIV] THE LEG 577 longus hallucis can be felt as it comes to the sur- face. The long and short peroneal muscles can be denned, and their tendons followed behind the malleolus. When in active contraction the in- terval between the two muscles is often well marked. The gastrocnemius muscle and the more superficial parts of the soleus are brought well into view when the body is raised upon the toes. The two heads of the former muscle are then quite conspicuous, and it can be seen that the inner head is the larger and descends lower in the leg. The popliteal artery bifurcates on a level with the lower part of the tubercle of the tibia (Fig. Ill, p. 549). The course of the posterior tibial vessel is represented by a line drawn from the middle of the limb at the lower part of the ham to a spot midway between the inner malleolus and the pro- minence of the heel. The artery becomes superficial in the lower fourth of the leg, where it may be felt pulsating between the tendo Achillis and the tibia. The peroneal artery arises about 3 inches below the knee, follows the posterior surface of the fibula, and ends behind the outer malleolus. The position of the anterior tibial artery may be in- dicated by a line drawn from a point midway between the outer tuberosity of the tibia and the head of the fibula to the centre of the front of the ankle-joint. Both the saphenous veins can often be made out in the leg. The inner or larger vein passes in front of the malleolus and ascends just behind the internal border of the tibia. With it runs the long saphenous nerve. The short saphenous vein lies behind the outer malleolus, and, passing up the middle of the calf, ends at the ham. It is accompanied by the external saphenous nerve. The skin is somewhat more adherent to the deeper parts in the leg than it is in the thigh. The difference in the degree of this adhesion is obvious when skin-flaps are dissected up from the two parts in cases of amputation. Over the in- ternal surface of the tibia and the greater part of the shin the integument lies directly upon the T 578 THE LOWER EXTREMITY [Chap. periosteum and bone, nothing intervening save a scanty amount of subcutaneous fascia. Thus blows and kicks over these parts of the leg are apt to be associated not only with much pain but also with much bruising or tearing of the integument. A " graze on the shin " is one of the commonest of lesions, and is produced by a degree of violence that upon a well-covered part would have little or no effect. It will be understood that ulcers over these feebly protected parts may, if they spread in depth, readily expose the bone and lead to some disease of its substance, or to at least some inflam- mation of its periosteum. Scars left by deep ulcers or burns are also often found to be quite adherent to the bone. The aponeurosis of the leg invests it like a tightly-drawn buskin, being lacking only over the subcutaneous surfaces of the bones (Fig. 120). It is attached to the head and the anterior and inner borders of the tibia, the head of the fibula, and the two malleoli. It is continuous above with the fascia lata, and below with the fascia of the foot and the annular ligaments. It is thicker in front than behind, and is especially thick at the upper part of the leg just below the knee. Here the fascia offers great resistance to the growth of tumours springing from the head of the tibia. From the deep surface of the aponeurosis two septa pass inwards to be attached to the anterior and ex- ternal borders of the fibula. They serve to isolate the two larger peroneal muscles from the other muscles of the limb, and form a closed space which might become a definite and well-localized cavity for pus. Beneath the gastrocnemius and soleus a layer of fascia extends between the two bones and covers in the deep layer of muscles. It is thin above but denser below, and would have some in- fluence in directing the progress of a deep abscess. In the upper third of the leg there is a septum between the tibialis anticus and extensor com- munis ^ digitorum, which must be found in the operation for ligaturing the upper part of the XXIV] VESSELS OF THE LEG 579 anterior tibial artery. I have never had the good fortune to see the very distinct " white line " that many text-books describe as indicating the posi- tion of this septum. In the substance of the soleus muscle there is a tendinous expansion connected with the inner border of the tibia. In cutting through the soleus to apply a ligature to the posterior tibial artery, this intersection may be mistaken for the aponeu- rosis on the deep surface of the muscle. Several cases are reported of rupture of some part of the gastrocnemius muscle during violent exertion. The tendo Achillis has been ruptured in like circumstances. This accident befell the celebrated John Hunter when dancing. It is said that the plantaris tendon is also not in- frequently torn across, producing a sudden sharp pain in the calf during exertion, to which the French give the name "coapde fouet." Vessels. — The large arteries of the leg, being all in close proximity to the bones, are apt to be injured by sharp fragments in fractures of the limb. This especially applies to the peroneal artery, which runs along the fibula in a fibrous canal, and is in considerable risk of being wounded in fractures about the middle of that bone. It is at the point of bifurcation of the popliteal artery that emboli are peculiarly apt to lodge. They plug the vessel and practically block ' the three main arteries of the leg. Gangrene, therefore, not infrequently follows the occurrence. Billroth states that in all the cases of gangrene of the leg due to embolism that he has met with, the plug was found situated at the bifurcation of the popliteal trunk ("Clinical Surgery," 1881). According to some French surgeons, aneurysm of the commencement of the posterior tibial artery is more often associated with gangrene of the leg than is a popliteal aneurysm. The reason they assign is the following : The aneurysm on the former vessel not only interferes with the passage of the blood into the posterior tibial and peroneal 580 THE LOWER EXTREMITY CChap. arteries, but also compresses the anterior tibial vessel, and with it the anterior tibial recurrent, an artery that is of so great importance in establish- ing the collateral circulation. Varicose veins are more commonly met with in the leg than in any other part of the body, save, perhaps, in the hemorrhoidal and spermatic veins. This depends upon the great length of the veins of the lower limb, the large columns of blood their valves have to support, their vertical posi- tion, the liability of the great trunks (iliac), into which they ultimately enter, to be compressed, and upon the fact that the superficial t veins, being outside the fascia, lose that assistance to the circulation derived | from muscular contraction. From a \ physical point of view the vascular \ c system must be regarded as a vertical r column of fluid. The lower the level | f the greater is the pressure on the con- taining walls. The saphenous veins ■ are thin-walled, distensible tubes situ- Fig. 119. ated outside the rigid-walled cylinder formed by the deep fascia of the leg and thigh, low in the body, where the pressure from gravity is greatest (Hill). The use pi garters especially affects the long saphenous vein, which lies close to the bone at the spot about which these contracting bands are usually applied. Between the two layers of the muscles of the calf ' Verneuil describes a venous plexus, which he be- lieves to be more often the seat of varices than are the vessels of the surface. A varicose condition of these deeply placed veins may explain the "aching legs" complained of by those who stand a great deal. The intramuscular veins are very large. Callender showed that six chief veins which pass from the soleus muscle to enter into the posterior tibial and peroneal trunks have a united diameter of not less than 1 inch. Varix would appear to commence most often at points where the deep veins join the superficial vessels. XXIV] PAIN TN THE LEG 581 There is good reason for this, for at these points three forces meet, the general directions of which are shown in the annexed diagram (Fig. 119). There is the weight of the superincumbent column of blood (a) acting from above, the resistance offered by the next valve below the point of entry of the deep vein acting from below (6), and the force with which the blood is driven by the con- tracting muscles out of the deep vein into the superficial trunk acting at an angle to both these lines of force (c). Unfortunately for the subjects of varices, the two principal veins (the saphenous) are accompanied by sensory nerves, and there is no doubt that much of the pain incident to vari- cose veins in the leg depends upon pressure on these nerves. With reference to pain in the leg, it must be remembered that the nerves that bring sensa- tion to the part arise at a considerable distance from their points of termination, and that the causes of pain in the limb may be situated far away from the seat of trouble. Thus, Sir B. Brodie mentions the case of a gentleman who suf- fered from severe pain in the left leg, from the foot to the knee, in the course of the peroneal nerve. No cause could be found for it. After the patient's death, however, a large tumour was found attached to the lumbar spine, which had evidently compressed the left great sciatic nerve. It is more difficult to offer an explanation, based on anatomical grounds, for cases such as those reported by Sir William Bennett, where the re- moval of a corn from the sole of the foot in one instance, and a tumour from the leg in another, led to the disappearance of a pain which was felt in the groin. There would appear to be little connexion between disease in the rectum and a pain in the leg, yet in one case at least that connexion was marked. " Only recently," writes Mr. Hilton, " I saw a gentleman from South Wales, who was the subject of stricture of the rectum from malignant 682 THE LOWER EXTREMITY [Chap. disease. He suffered pain in the knee-joint and in the back part of the leg. This led me to suspect — what really turned out, upon careful examina- tion, to be the case — that a large mass of cancer was involving the nerves on the anterior part of the sacrum, and also, no doubt, the obturator nerve/' Dr. Ralfe mentions cases of renal calculus attended by severe pain in the sole of the foot, and I have met with many instances of this as- sociation, the pain being most commonly in the heel. Fractures of the leg-.— Of the bones of the leg the tibia and fibula are more often broken together than singly, and of separate bones the fibula is more often fractured than is the larger bone. 1. The tibia and fibula. — As regards the re- sistance it offers to violence the fibula presents about the same degree of strength in all its parts, save at the malleolus and at its upper extremity. Its great length and the manner of its attachment to the tibia (its two ends being fixed and its main part being unsupported) render it a slender bone, and but for the efficient protection it derives from the thick pad of muscles that surrounds it, it would no doubt be very frequently broken. This is all the more likely to be the case, since the bone is placed upon the more exposed aspect of the limb. The shaft of the tibia presents various degrees of strength, according as we regard its upper, middle, or lower third. According to Dr. Leriche, the average transverse diameter of the adult tibia just below the tuberosities is a little over If inches. The transverse diameter at the base of the malleolus is a little less than if inches, and that of the narrowest part of the bone is a little more than 1 inch. This narrow part is at the junction of the lower with the middle third of the shaft, and is the weakest point in the bone. The relation of the compact to the cancellous XXIVJ FRACTURES OF THE LEG 583 tissue is about the same in all parts of the shaft; but, according to MM. Fayel and Duret, the spongy tissue is arranged in two independent ver- tical columns, one occupying the upper two-thirds and the other the lower third of the bone. The minimum of resistance (these authors assert) is at the point where these two systems meet. Thus it happens that the most common spot for a frac- ture of the tibia is at the junction of the middle with the lower third of the shaft. It is here that the bone yields when broken by indirect violence, while the lesions depending upon direct violence may be at any part of the shaft. Owing to the thin covering of soft parts, and the slight barrier interposed between the fracturing force and the bone, it comes to pass that fractures of the leg are more often compound and comminuted than are those of any other bones of the extremities. If the fracture be oblique, as is commonly the case when the violence is indirectly applied, the line of breakage usually extends from behind, down- wards, forwards, and a little inwards. The lower fragment, with the foot, is drawn up behind the rest of the bone by the muscles of the calf, and is usually displaced also outwards by the obliquity of the fracture line. Often the lower fragment is slightly rotated outwards by the rolling over of the foot, a rotation produced by the simple weight of the limb. If the fracture be transverse there may be little or no displacement. The fibula is usually broken at a higher level than the tibia, and its lower fragment follows, of course, with absolute precision the corresponding fragment of the larger bone. A remarkable spiral fracture (fracture helicoide), involving the lower third of the^ tibia, has been described by French surgeons. It is associated with a more or less vertical fissure that involves the ankle-joint, and with a fracture of the fibula high up. MM. Leriche and Tillaux have shown that this injury is due to torsion, especially to some twisting of the leg while the foot is fixed. 584 THE LOWER EXTREMITY [Chap. 2. The fibula alone.— Fractures of this bone in its lower fourth are usually due to indirect vio- lence, and will be dealt with in connexion with the ankle-joint. When it is broken in any other part the fracturing force is usually directly ap- plied, the lesion transverse, and the displacement insignificant, or scarcely obvious. The tibia acts as an efficient splint. Peron. Lonq. Ant. Tib. Art. Peron. Art. Flex. Long. Hall. Post. Tia N. Gastrocnem. Fig. 120. — Section across the leg at the junction of the upper and middle thirds. (After Braune.) 3. The tibia alone. — The malleolus may be broken by a blow, or the lower epiphysis sepa- rated. The latter comprises the whole of the inner malleolus and the facet with which the fibula articulates. It joins the shaft during the eigh- teenth or nineteenth year. Fractures of the tibia alone are nearly always due to direct violence, and whilst most common in the lower third of the bone, become more rare as the knee is approached. When transverse there may be no visible displace- ment, the fibula acting as a splint. Thus, Sir Henry XXIV] FRACTURE OF THE TIBIA 585 Morris mentions the case of a woman who walked into and out of a hospital with a transverse frac- ture of the tibia that was not detected on examina- tion, and was not indeed discovered until two days after the accident. When the fracture is just above the ankle the lower fragment may be moved in whatever direction the foot is forced, such dis- Fig. 121. — Transverse section through the lower third of the leg. {Br mine.) a, Tibialis anticus ; b, extensor longus hallucis ; e, extensor communis digitorum ; d, peroneus brevis ; e, peroneus longus ; /, tibialis posticus ; r/, flexor longus digitorum ; h, flexor longus ballucis ; i, gastrocnemius and soleus ; j, short saphenous nerve and vein ; k, anterior tibial vessels and nerve ; Z, peroneal vessels ; TO, pos- terior tibial vessels and nerve ; n, musculo-cutaneous nerve. placement being resisted and limited by the in- ferior tibio-fibular ligaments. In rickets the tibia is, of all the bones of the extremities, the one that most frequently becomes bent. It yields at its weakest part (the lower third), and there the bone will be found to have developed a curve forwards and a little outwards. Amputation of the leg at the junction of the upper with the middle third by unequal antero- 586 THE LOWER EXTREMITY [Chap. XXIV posterior flaps may be taken as an example {set Fig. 120). In the anterior flap the following structures would be cut : Skin, cutaneous nerves, fascia, tibialis m anticus, extensor communis digitorum and a little of the extensor proprius hallucis, the peroneus longus and a small part of the upper extremity of the peroneus brevis, the anterior tibial vessels and nerve, and the musculo- cutaneous nerve. In the posterior flap the follow- ing would be the parts divided : Skin, external and internal saphenous veins and nerves, fascia, gastrocnemius, plantaris, soleus, tibialis posticus, flexor longus digitorum, a little of the upper end of the flexor longus hallucis, the posterior tibial vessels and nerve, and the peroneal vessels. In Fig. 121 is shown a transverse section of the leg at the lower third, from which can be gathered an idea of the number and position of the parts cut in amputations through that part. An excellent method of amputation at the upper part of the leg is by a single external flap containing the anterior tibial artery in its entire length. CHAPTER XXV THE ANKLE AND THE FOOT Surface anatomy. Bony points. —The outlines of the two malleoli can be very distinctly denned. The external is somewhat the less prominent, descends lower, and lies farther back than the internal process. The tip of the outer malleolus is about i an inch behind and below the tip of the corresponding bony prominence. The antero- posterior diameter, however, of the internal mal- leolus is such that its posterior border is on a level with that of the outer process behind. On the dorsum of the foot the individual tarsal bones are not to be distinguished, although the astragalus forms a distinct projection upon that surface when the foot is inverted. On the inner side of the foot the tuberosity of the os calcis may be felt most posteriorly. In front of it, and about 1 inch vertically below the inner malleolus, is the projection of the sustenta- culum tali. About lj inches in front of the mal- leolus the tuberosity of the scaphoid can be dis- tinctly made out (Fig. 125, p. 611). In the interval between it and the last-named process lie the inferior calcaneo-scaphoid ligament, and the ten- don of the tibialis posticus. Farther towards the front of the foot can be felt the ridge formed by the base of the first metatarsal bone, and between it and the scaphoid tubercle lies the inner cunei- form bone. Lastly, the shaft of the first meta- tarsal bone, its expanded head, and the sesamoid 587 588 THE LOWER EXTREMITY [Chap. bones that lie on the plantar aspect of the meta- tarsal phalangeal joint can be more or less dis- tinctly denned. On the outer side of the foot the external surface of the os calcis is subcutaneous in nearly the whole of its extent. Less than 1 inch below and in front of the malleolus is the peroneal tubercle, with the short peroneal tendon above it and the long one below it. Some 2j inches from the outer malleolus the projection of the base of the fifth metatarsal bone is very evident, and ex- tending for an inch or so behind it lies the cuboid bone. Joint lines.— The ankle-joint lies about on a level with a point J an inch above the tip of the inner malleolus. Immediately behind the tubercle of the scaphoid is the astragalo-scaphoid articula- tion, and a line drawn transversely across the dorsum of the foot, just behind the process, very fairly corresponds to the mid-tarsal joint (the joint compounded of the astragalo-scaphoid and calcaneo-cuboid articulations). If the latter articulation be approached from the outer side it will lie opposite a point midway between the outer malleolus and the prominent base of the fifth metatarsal bone. The lines of the articulations between the first and fifth metatarsal bones and the inner cunei- form and the cuboid respectively are easily indi- cated, being placed just behind the bases of the former bones. The metatarso-phalangeal articula- tions are situated about 1 inch behind the webs of the corresponding toes. The proximal phalanx and part of the middle are buried in the web. Tendons. — The tendo Achillis stands out very conspicuously at the back of the ankle, and be- tween it and the malleoli are two hollows which are evident in even obese individuals. Over the front of the ankle the tendons of the extensor muscles are readily to be distinguished, especially when the joint is flexed. From within outwards they are : the tendons of the tibialis anticus, ex- tensor longus hajlucis, extensor longus digitorum, XXV] ANKLE AND FOOT 580 and peroneus tertius. Beneath the tendons of the extensor of the toes, and on the outer part of the dorsum of the foot, the prominent fleshy mass formed by the extensor brevis digitorum can be felt and, when in action, seen. Above and behind the inner malleolus the tendons of the tibialis posticus and flexor longus digitorum can be dis- cerned, the former lying nearer to the bone. Nearer to the middle line runs the flexor longus hallucis. Behind the outer malleolus the long and short peroneal tendons can be felt, lying close to the edge of the fibula, the tendon of the smaller muscle being the closer to it. In the middle of the sole of the foot the resist- ing plantar fascia can be felt, and some of its processes made out when the toes are drawn up by the extensors. The fleshy mass on the inner margin of the foot is formed by the abductor and flexor brevis hallucis; that on the outer side by the abductor and flexor brevis minimi digiti. Vessels. — The anterior tibial artery and nerve are placed opposite the ankle-joint, between the tendons of the extensor proprius hallucis and longus digitorum. The dorsal artery runs from the middle of the ankle to the interval between the bases of the first and second metatarsal bones. It may be felt pulsating against the bones along the outer side of the extensor proprius hallucis tendon, which is the readiest guide to it. The plantar arteries start from a point midway be- tween the tip of the malleolus internus and the centre of the convexity of the heel. The internal vessel follows a line drawn from this point to the middle of the under surface of the great toe. The external vessel crosses the sole obliquely to within a thumb' s-breadth of the base of the fifth meta- tarsal bone. From thence it turns more trans- versely across the foot, running inwards over the bases of the metatarsal bones to inosculate with the dorsalis pedis artery at the back of the first interosseous space. On the dorsum of the foot the subcutaneous veins may be seen forming an arch 500 THE LOWER EXTREMITY [Chap. convex towards the toes, and from the ends of the arch vessels may be followed into the internal and external saphenous veins. The skin about the ankle and over the dor- sum of the foot is thin and but loosely attached to the subjacent parts. It becomes readily ex- coriated, as is frequently the case where splints or instruments have been improperly applied. Since the skin over the malleoli lies directly upon the bone, while that covering the dorsum of the foot is but slightly separated from the bones of the tarsus, it follows that the integu- ments in this region are readily contused, and may suffer gangrene from an amount of pressure that would cause but little trouble in other parts. Over the sole the integument is dense and thick in all those parts that come in contact with the ground. In the normal foot, the heel, the outer margin of the foot, and the line of metatarso- phalangeal joints are in contact with the ground when the sole is placed flat upon it (Fig. 126, p. 612). The subcutaneous tissue about the ankle and foot varies greatly both in quantity and charac- ter. Over the front of the ankle and dorsum of the foot it is very lax, free from fat, and is the first part to be infiltrated in general dropsy of the body. On the sole the subcutaneous tissue is dense, firm, and studded with pellets of fat. It is | of an inch thick over the heel. The integuments of the foot are well supplied with nerves, being furnished with branches from no less than six nerve trunks, the musculocutane- ous, the anterior tibial, the two saphenous, and the external and internal plantar. Many Paci- nian bodies are found upon these cutaneous branches, and end-bulbs are met with in the skin on the sole. The integuments of the foot respond acutely to sensations of pain, of pressure, of tem- perature, and to certain unwonted forms of tac- tile impression, such as tickling. Tactile sensi- bility, however, as measured by the sesthesiometer, XXV] ANKLE AND FOOT 591 is not acute, the dorsum of the foot showing, in regard to this matter, no more sensitiveness than does the skin of the buttock. Over the " tread of the foot," and especially under the ball of the great toe, the peculiar affection known as "perforating ulcer" is most commonly met with. This ulcer occurs as an occasional symptom in certain nerve maladies, and particularly in locomotor ataxy. Fasciae of the foot and the tendons about the ankle. — The fasciae on the dorsum occur in two layers, a superficial one that is con- tinued from the anterior annular ligament, and a deeper placed over the extensor brevis and inter- ossei muscles. These membranes are both thin and insignificant, and exercise no influence from a surgical point of view. The plantar fascia is divided into three parts, a central or main por- tion which is extremely dense and powerful, and two lateral expansions which are thin and surgi- cally insignificant. The outer of the two lateral portions is, however, of some substance, and forms a very thick band between the os calcis and fifth metatarsal bone, that may become rigidly con- tracted in some forms of talipes. The central ex- pansion assists greatly in supporting the antero- posterior arch of the foot, which it tends to main- tain in the manner that the bowstring maintains the arch of the bow. The sinking of the arch that occurs in " flat foot y is associated with marked yielding of this fascia. The plantar fascia is often found much contracted (as a rule, secondarily) in certain forms of club-foot, such as talipes equinus and congenital varus. The term " talipes cavus " is applied to a deformity that depends mainly or entirely upon a contraction of the plantar fascia. The best place in which to divide this membrane is at a spot about 1 inch in front of its attachment to the os calcis. This is its narrowest part, and the knife (which should be introduced from the inner side) will be behind the external plantar 592 THE LOWER EXTREMITY [Chap. artery which runs beneath the expansion. An abscess situated beneath the membrane will be very closely bound down, and will advance in any direction other than through the membrane itself so as to point in the centre of the sole. Such deep collections cause intense pain, and often much destruction, before they are discharged. They may open upon the dorsum, or may extend up along the tendons to the region of the ankle. There are certain foramina or spaces in the sub- stance of this layer occupied usually by fat; through one or more of these an abscess will, in exceptional cases, extend, and then spread out be- neath the integuments. Such an abscess will have, therefore, two cavities united by a small hole, and will form the abces en bissac or en bouton de chemise of the French. The plantar fascia divides into slips near the roots of the toes, and forms a series of arches, beneath which pass the tendons, vessels, and nerves bound for the digits. Two intermuscular septa connected with the membrane separate the flexor brevis digitorum from the ab- ductor^ hallucis on the one side and the abductor minimi digiti on the other. They are, however, membranes of too feeble a structure to affect much the progress of a deep plantar abscess. The anterior annular ligament is divided into two parts; an upper band in front of the tibia and fibula, and a lower band in front of the upper limits of the tarsus (Fig. 122). Beneath the former there is only one synovial sheath, that for the tibialis anticus ; beneath the latter are three sheaths — one for the peroneus tertius and extensor communis, one for the extensor proprius pollicis, and a third for the tibialis anticus. According to Holden, there is often a large irregular bursa between the tendons of the ex- tensor longus digitorum and the projecting end of the astragalus. This bursa sometimes communi- cates with the joint at the head of the astragalus. Beneath the internal annular ligament are three synovial sheaths for the tendons of the XXVJ ANKLE AND FOOT 593 tibialis posticus, flexor longus digitorum, and flexor longus hallucis. Inflammation involving the sheath for the tibialis posticus may spread to Upper Ant. Ann. Liq. Lower Ant. Ann. Liq. Peron. Tertius Ext. Long. Hall. Ext. Brev. Hall. Fig. 122. — Synovial sheaths on the extensor surface of foot and ankle. [Lovell and Tanner.) the ankle-joint, with which the tendon is in close relation. Beneath the outer annular ligament is the single synovial sheath for the long and short peroneal tendons. In severe sprains of the ankle not only are the 594 THE LOWER EXTREMITY [Chap. ligaments about the joint more or less ruptured, but the various synovial sheaths just named are apt to be torn and filled with blood. The long abiding trouble in the part that often follows severe sprains depends to a great extent upon damage to these sheaths, and to extravasations of blood, and subsequently of inflammatory material, within thorn. These sheaths are more extensive than they are usually supposed to be ; those at the inner side of the ankle commence from 1 to 2 inches above the malleolus, and extend into the sole of the foot to a point opposite the tuberosity of the scaphoid. Those at the outer side of the ankle are even more extensive, that round the peroneus longus extending to the base of the first meta- tarsal, although occasionally the plantar and mal- leolar parts may be found completely separated from each other at the outer border of the cuboid. From the length of the sheaths it can be readily understood that the adhesions which follow sprains and fractures at the ankle are very ex- tensive, unless passive movements be carried out to prevent their formation. There are few bursae of any magnitude about the foot, save one between the tendo Achillis and os calcis, and another over the metatarso-phalan- geal joint of the great toe. The first-named bursa rises up about \ an inch above the os calcis, and bulges out on either side of the tendon. When in- flamed it may produce symptoms like those of ankle-joint disease, and when suppurating may lead to caries of the os calcis. The enlargement of the bursa over the metatarsophalangeal joint of the great toe constitutes a bunion. It lies in the subcutaneous tissue between the internal sesamoid and the skin, and is not present at birth. This condition is generally brought about by impro- perly shaped boots, which force the great toe out- wards, place it obliquely to the long axis of the foot, and render the metatarsal joint very promi- nent. The cartilage over the inner part of the head of the metatarsal bone disappears, and a XXV] ANKLE ANt) FOOT 505 communication between the bursa and joint may be set up. The result of this deformity is a great weakening of the toe and adjacent part of the foot, a lengthening of the internal lateral liga- ment of the joint, and a displacement outwards of the tendon of the extensor proprius hallucis. Bursae are often developed over the malleoli in tailors, and especially over the external process, the part most pressed upon when sitting cross- legged. In club-foot, bursse are found over any points that are exposed to undue pressure. The tendons about the ankle are not infre- quently ruptured by violence. Those that most often are so injured are the tendo Achillis and the tendons of the tibialis posticus, and long and short peroneal muscles. The tendo Achillis usually breaks at a point about lj inches above its inser- tion, where it becomes narrowed and its fibres collected into a very definite bundle. In some forms of violence the synovial and fibrous sheaths that bind down a tendon may be ruptured and it may be allowed to become dis- placed. This has happened to the tibialis posticus and peroneal muscles. In each instance the dis- located structure comes forward upon or in front of the malleolus. No tendon in the body is so frequently displaced as is that of the peroneus longus. The tendons about the ankle are frequently divided by operation. The tendo Achillis is usually cut about 1 inch above its insertion, the knife being entered from the inner side to avoid the posterior tibial vessels. The tibialis posticus tendon is, as a rule, divided just above the base of the inner malleolus. There is, however, enough room between the annular ligament and the sca- phoid bone to cut it on the side of the foot (Fig. 125, p. 611). The anterior tibial tendon may be divided readily either in front of the ankle or at its insertion into the internal cuneiform bone. On section of a tendon a gap is felt, owing to retrac- tion by the muscle. The cut ends are still united 596 THE LOWER EXTREMITY [Chap. by the fibrous tissue in which they lie, and from which they derive their blood supply. If cut within a sheath the synovial membrane forms a loose binding between the cut ends. A fibrous band between the cut ends is ultimately formed from the effusion which fills the gap. The new band is firmly adherent to the sheath in which it lies, and at first will limit the movements of the tendon. Part of the tendon of a sound muscle may be yoked to that of one which has become paralysed, thus restoring certain movements to the foot. Blood-vessels. — The lines of the various arte- ries have been already indicated (p. 580). Wounds of the plantar arch are serious, on account of the depth at which the external plantar artery lies, and the impossibility of reaching the vessel with- out making a large wound in the sole that would open up important districts of connective tissue and do damage to tendons and nerves. The arch is formed by the junction of the external plantar artery with the dorsal artery of the foot, a con- tinuation of the anterior tibial vessel. In cases, however, of bleeding from the arch, ligature of both the posterior and anterior tibial vessels at or just above the ankle would not necessarily arrest the haemorrhage. After ligature of these vessels blood would still be brought indirectly to the arch by means of the peroneal artery. By its anterior peroneal branch this vessel communicates with the external malleolar branch of the anterior tibial artery, and with the tarsal branch of the dorsalis pedis. By its terminal branch it communicates with the two last-named vessels, and also with the internal calcaneal branches of the external plan- tar artery. As a matter of practice, however, elevation of the limb, together with pressure upon the wounded point and compression of the main artery, is sufficient to check most haemorrhages from the plantar arch. The dorsalis pedis artery, from its superficial position and its close contact with the bones of the XXV] ANKLE AND FOOT 597 foot, is frequently divided in wounds and rup- tured in severe contusions. The posterior tibial artery at the ankle is well protected by the pro- jecting malleolus, the dense annular ligament, and the tendons that run by its side. The superficial veins of the foot, like those of the hand, are found mainly upon the dorsum of the member. The sole, as a part exposed to pres- sure, is singularly free from them. About the malleoli, and especially about the inner process, these veins form a considerable plexus. Hence it is that appliances which fit tightly around the anklo are apt to produce oedema and pain in the parts beyond. The dull pain in the feet that is often caused by tight elastic-side boots is probably due to the same cause. The lymphatics forrn^ a very fine and elabo- rate plexus in the coverings of the sole, from which vessels arise that reach the borders and dor- sum of the foot, and principally the inner border. The main lymph-vessels of the part are found upon the dorsum, about the radicles of the two saphenous veins. Those on the inner side of the foot are by far the more numerous; they follow pretty generally the course of the internal saphen- ous vein, and end in the inguinal glands. The external vessels pass up along the outer ankle and outer side of the leg. The bulk of them pass obliquely across the ham to join the inner set above the knee ; others reach the inner set bv cross- ing the front of the tibia, while a few follow the short saphenous vein and end in the popliteal glands {see p. 557). The ankle-joint is a very powerful articula- tion, its strength being derived not only from the shape of its component bones, but also from the unyielding ligaments and many tendons that are bound about it like straps. Of the ligaments, the two lateral are very strong, and have an extensive hold upon the foot. The anterior and posterior are extremely thin and insignificant, although the latter is supported by the tendon of the flexor 598 THE LOWEE EXTREMITY [Chap. longus hallucis, which crosses it. When effusion takes place into the joint, it first shows itself in front, beneath the extensor tendons, and just in front of the lateral ligaments. This is due to the feebleness of the anterior ligament and the extent and looseness of the synovial sac in relation with that structure. More extensive effusions cause a bulging behind through yielding of the thin pos- terior part of the capsule, and fluctuation can then be obtained on either side of the tendo Achillis. In no ordinary case can fluctuation be detected distinctly beneath the unyielding lateral ligaments. Moreover, the loose synovial sac of the ankle-joint extends both in front and behind be- yond the limits of the articulation, while, at the sides, it is strictly limited to the joint surfaces. The ankle is a perfect hinge-joint, and permits only of flexion and extension. The very slightest amount of lateral movement is allowed in extreme extension, when the narrower, or hinder, part of the astragalus is brought into contact with tne widest, or anterior, part of the tibio-fibular arch. When obvious lateral movement exists at the ankle, the joint must be the seat of either injury or disease ; and it is important not to mistake the lateral movements permitted between certain of the tarsal bones for movements at the ankle- joint. Dorsi-flexion is limited by the posterior and middle parts of the internal ligament, by the posterior part of the external ligament, by the pos- terior ligament, and by the contact of the astra- galus with the tibia. Plantar flexion is limited by the anterior^ fibres of the inner ligament, the anterior and middle parts of the outer ligament, by the anterior part of the capsule, and the con- tact of the astragalus with the tibia. Owing to its exposed position, this joint is very liable to become inflamed from injury or other external causes. When inflamed, no dis- tortion is, as a rule, produced, the foot remaining at right angles with the leg. It would appear that this position is due to the circumstance that XXVj DISLOCATIONS AT ANKLE-JOINT 599 the flexor and extensor muscles about balance one another, and it does not seem that the capacity of the joint is affected by the posture of the foot. The synovial cavity of the ankle is in communica- tion with the inferior tibio-fibular articulation. In connexion with the subject of " referred pains/' it should be remembered that the nerves supplying the ankle-joint bring that articulation into relation with the lumbar segments of the spinal cord through the internal saphenous, and the sacral segments through the anterior tibial nerve. Dislocations at the ankle-joint. — The foot may be dislocated at the ankle in five directions, which, placed in order of frequency, are : outwards, inwards, backwards, forwards, and upwards be- tween the tibia and fibula. These dislocations are nearly always associated with fracture of either the tibia or fibula or of both bones. 1. The lateral dislocations : Outwards, in- wards. These luxations differ somewhat from those met with in other joints. In the great majority of cases they consist of a lateral twisting of the foot, of such a kind that the astragalus is rotated beneath the tibio-fibular arch. There is no great removal of the upper surface of the astra- galus from that of the tibia, one or other edge of the former bone being brought in contact with the horizontal articular surface of the latter. Although much deformity is produced, the actual separation of the foot from the leg is not con- siderable. In some rare cases a true lateral dis- location in the horizontal direction has been met with. These injuries are due to sudden and violent twistings of the foot, and are in nearly every in- stance associated with fractures of the tibia or fibula. The luxation outwards is due to forcible eversion of the foot, the luxation inwards to vio- lent inversion. It is of interest, in the first place, to note the relation of the fibula to injuries at the ankle- 600 THE LOWER EXTREMITY [Chap. joint, especially as a fracture of the lower end of the shaft of that bone may follow alike upon both inversion and eversion of the foot. The lower 3 or 4 inches of the fibula may be considered to form a lever of the first kind (Fig. 123, a). The fulcrum Fig, 123. — Diagrams to illustrate the mechanism involved in fractures of the lower end of the fibula. A, Parts in normal position: a, tibio-iibular ligaments; b, external lateral ligament ; c, internal lateral ligament. B, Fracture of fibula due to eversion of foot. C, Fracture of fibula due to inver- sion of foot. is at the inferior tibio-fibular articulation, one arm of the lever is the malleolus below that joint, while the other arm may be regarded as formed by the lower 2 or 3 inches of the shaft of the bone. Now the lower ends of the tibia and fibula are bound together by verv powerful ligaments, viz. the anterior and posterior tibio-fibular, the trans- XXV] DISLOCATIONS AT ANKLE-JOINT GDI verse, and the inferior interosseous. I would ven- ture to insist particularly that in no ordinary lesion about the ankle, whether fracture or dis- location, do these ligaments give way. If they should yield, then an anomalous form of fracture or luxation would be produced. In forcible eversion of the foot, the internal lateral ligament becomes stretched and tears, the astragalus is rotated laterally beneath the tibio-fibular arch and is brought into violent contact with the end of the outer malleolus. This process is pushed outwards, and acts as one end of a lever. The fulcrum is secured by the unyielding tibio-fibular ligaments, and the fibula breaks at the other end of the lever, a point some 2 or 3 inches above the end of the bone (Fig. 123, b). In forcible inversion of the foot, the astragalus undergoes a little lateral rota- , tion in the opposite direction ; the external lateral ligament is greatly stretched, and tends to drag the end of the outer malleolus inwards. If the ligament yields, the case will probably end as a sprained ankle, or pass on to a dislocation in- wards of the foot. But if it remains firm, the end of the fibular lever (the tip of the malleolus) is drawn towards the middle line, the fulcrum is secured by the tibio-fibular ligaments, and the shaft breaks at the other end of the lever, some few inches above the end of the bone (Fig. 123, c). It will be seen that in the fracture due to eversion the upper end of the lower fragment is displaced towards the tibia, while in the lesion due to in- version it is displaced from that bone. From a careful examination of all the cases of fracture of the lower end of the fibula admitted into the London Hospital during the time I held the post of surgical registrar there, I convinced myself that the lesion is much more frequently due to eversion than to inversion of the foot. I think it may be said that a fracture of the lower end of the fibula due to simple inversion of the foot is not pos- sible unless the external lateral ligament remains entire. 002 THE LOWER EXTREMITY [Chap. In the outward luxation, better known as Pott's fracture, the condition is such as has just been described in connexion with the effects of eversion of the foot upon the fibula. That bone is always broken some 2 or 3 inches above the malle- olus, the deltoid ligament is torn, or the tip of the inner malleolus wrenched off. The astragalus is so rotated laterally that the foot is much everted, its outer edge raised, while its inner edge rests upon the ground. The inferior tibio- fibular ligaments remain intact. If they yield, an unusual form of fracture or dislocation is pro- duced, as already stated. Boyer relates a case, considered to be unique, where the foot was lux- ated outwards, but without any fracture of the fibula. That bone, however, had been forced up- wards entire, and its head dislocated from the articular facet of the tibia. A horizontal disloca- tion outwards, without rotation of the foot and without fracture of the fibula, is possible if the inferior tibio-fibular ligaments are entirely torn. In Dupuytren's fracture (a rare injury) the fibula is fractured from 1 to 3 inches above the malleolus, the inferior tibio-fibular ligaments are entirely lacerated, or the portion of the tibia to which they are attached is torn away, and remains connected with the lower fragments of the fibula. The foot is dislocated horizontally outwards, and is drawn upwards, the extent of the upward dis- placement depending upon the height at which the fibula breaks. In the inward luxation the external lateral ligament is torn or the tip of the outer malleolus dragged away, the deltoid ligament is intact, but the internal malleolus is commonly^ broken by^ the violence with which the astragalus is brought into contact with it. That bone itself may be broken, and is in any case rotated laterally, so that the foot is inverted and its inner border much raised. In all forms of this dislocation, whether simple or complicated, the inferior tibio -fibular ligament remains intact. XX Vj ANKLE AND FOOT ($03 2. The antero-posterior dislocations : Back- wards; forwards. These injuries are brought about by great force applied to the foot while the leg is fixed, or more commonly by sudden arrest of the foot during some violent impulse given to the body, as on jumping from a carriage when in motion. In the luxation backwards the astra- galus is displaced behind the tibia, while the articular surface of the latter bone rests upon the scaphoid and cuneiform bones. The anterior and posterior ligaments are entirely torn, and a great part also of the two lateral bands. The fibula is broken some 2 or 3 inches above the mal- leolus, and there is usually a fracture also of the inner malleolus. The luxation forwards is of extreme rarity. In the few reported cases one or both malleoli were broken. R. W. Smith believes that the dis- location is never complete. 3. The dislocation upwards. In this rare acci- dent the inferior tibio-fibular ligaments are rup- tured, the two bones are widely separated at their lower ends, and the astragalus is driven up be- tween them. The anterior and posterior ligaments are entirely ruptured, but the lateral ligaments usually escape with but some slight laceration. The accident appears to be generally caused by a fall, the patient alighting flat upon the soles of the feet. Mr. Bryant records a case in which both feet were similarly dislocated upwards. The foot. — There are two arches in the foot, an antero-posterior and a transverse. 1. The antero= posterior arch has its summit at the astragalus. It may be considered as composed of two piers. The hinder pier consists of the os calcis, the anterior pier of the scaphoid, cunei- form and metatarsal bones. The astragalus forms the keystone of the arch, the head of the bone especially performing that function (Fig. 124). The foot rests upon the heel, the heads of the metatarsal bones, and the outer margin of the foot (Fig. 126). The hinder pier is solid, is made up G04 THE LOWER EXTREMITY [Chap. of a strong bono, and contains only one joint. It serves to support the main part of the weight of the body, and gives a firm basis of attachment to the muscles of the calf. The anterior part of the arch, on the other hand, contains many small bones and a number of complicated joints. It serves to give elasticity to the foot, and to diminish the effect of shocks received upon the sole of the foot. The comparative value of the Fig. 124. -Antero-posterior section of the foot, (Rildinger.) 1, Tibia ; 2, astragalus ; 3, os calcis ; 4, scaphoid ; 5, int. cuneiform ; 6, first metatarsal bone ; 7 and 8, phalanges of great toe. two piers of the arch in this latter respect can be estimated by jumping from a height and alight- ing first upon the heels and then upon the balls of the toes. The inner part of the arch is much more curved than the outer, and forms the instep. 2. The transverse arch is most marked across the cuneiform bones. It gives much elasticity to the foot and affords protection to the vessels of the sole. XXV] INVERSION AND EYERSION OF FOOT 605 These two arches result from the shape of the component bones, and are maintained by the vari- ous ligaments and muscles of the sole. The pero- neus longus tendon, and nearly all the ligaments which connect the first and second rows of tarsal bones on both the plantar and dorsal aspects, are inclined forwards and inwards, and by this arrangement are well adapted to maintain the integrity of the transverse as well as of the antero-posterior arch. The movements of inversion and eversion, whereby the foot is adapted to the ground on which it treads, occur at the subastragaloid joints. These are two in number — (l) the anterior subastragaloid joint between the head of the astra- galus and three other parts : (a) sustentaculum tali; (b) inferior calcaneo-scaphoid ligament; (c) scaphoid (Fig. 124) ; (2) posterior subastra- galoid between the body of the astragalus and os calcis. The posterior is separated from the an- terior joint by the interosseous ligament. A third joint is also concerned in these important move- ments, viz. that between the os calcis and cuboid. The muscles which produce inversion are (1) tibi- alis posticus, (2) tibialis anticus. The first pro- duces eversion with plantar flexion, the others with dorsal flexion. The flexor muscles of the toes assist the first, the extensor of the great toe the second. Eversion is produced by (1) peroneus longus, (2) peroneus brevis, (3) peroneus tertius, (4) the extensor longus digitorum. The first pro- duces eversion with plantar flexion, the others with dorsal flexion. Thus there are four groups of muscles acting on the subastragaloid articula- tions which balance and determine the movements of the foot, and four positions in which they may fix the foot : (1) inversion with plantar flexion (talipes equino-varus) ; (2) eversion with plantar flexion (talipes equino-valgus) ; (3) inversion with dorsi-flexion (talipes calcaneo-varus) ; (4) eversion with dorsi-flexion (talipes calcaneo-valgus). The position assumed will depend on the group or 606 THE LOWER EXTREMITY [Chap. groups of muscles which are paralysed or weak- ened. Eversion is limited by the inferior calcaneo- scaphoid ligament and the structures along the inner side of the sole of the foot — the abductor hallucis, plantar fascia, and the tibial muscles. Inversion is limited by the tuberosity of the scaphoid coming in contact with the sustenta- culum tali, the peroneal muscles, and ligaments along the outer border of the foot. The move- ments of inversion and eversion correspond to supination and pronation, but in the upper ex- tremity these are produced between radius and ulna, whereas in the lower extremity they occur almost entirely between the astragalus and the rest of the foot. Dislocation of the astragalus. — This bone is sometimes luxated alone, being separated from its connexions with the os calcis, the tibia, the fibula, and the scaphoid bone. The displacement may be either forwards, backwards, or laterally. The luxation forwards is by far the most common lesion, the next in frequency being a luxation outwards and forwards. In these injuries the interosseous ligament between the os calcis and astragalus is entirely torn, as are also the greater part of the lateral ligaments of the ankle, and the various bands that connect the astragalus with the os calcis and scaphoid. In all instances the malleoli are brought nearer to the sole. Radio- graphy has shown that fracture not infrequently accompanies dislocation of the astragalus. When it is remembered that the astragalus is the key- stone of the plantar arch, and must receive the chief impact in all accidents which force the weight on the feet, the fracture of its neck or of its body becomes intelligible. Dislocation of the os calcis. — This bone, al- though often fractured, is very rarely luxated. When displaced, however, it is usually displaced outwards, and is torn away from its attachments to the astragalus and cuboid, or from the former bone alone. XXV] DISLOCATIONS OF FOOT 007 Subastragaloid dislocations of the foot. — In these lesions, which are not very uncommon, the astragalus remains in position between the tibia and fibula, while the rest of the foot is dislo- cated below that bone. The luxation, therefore, concerns the anterior and posterior subastraga- loid joints. The foot may be displaced either forwards, backwards, or laterally. The forward dislocation is extremely rare, and the lateral luxa- tions are nearly always oblique. In the most usual displacements the loot is dislocated outwards or inwards, and is at the same time carried back- wards. These luxations are frequently compound, especially when lateral. They are, as a rule, incomplete as regards the anterior subastragaloid joint, while, on the other hand, the displacement of the astragalus from the scaphoid is in nearly every instance complete. In all cases the inter- osseous ligament between the os calcis and astraga- lus must be torn, and there will also be more or less laceration of the ligaments joining the astragalus to the scaphoid and to the malleoli. The malleoli are very often fractured. It is only necessary to notice in any detail the two lateral luxations, as being the only common forms. In the inward dislocation the foot is in- verted, its inner border is raised, is shortened, and rendered concave, while its outer border is lengthened and made convex. The deformity much resembles that of talipes varus. The head of the astragalus with the outer malleolus forms a projection at the outer aspect of the foot, while below them a deep hollow exists. The inner border of the os calcis is very prominent at the internal side of the limb, while the inner malleolus is buried in the hollow left by the displacement of that bone. The calcaneum and scaphoid are ap- proximated. In the outward luxation the foot is abducted, its outer border is raised, and the deformity produced is not unlike that of talipes valgus. The outer malleolus is lost in the hollow caused by the eversion of the foot, while the tibial 608 THE LOWER EXTREMITY [Chap. malleolus and head of the astragalus form a pro- jection on the inner aspect of the limb. The mediotarsal joint is situated between the head of the astragalus and scaphoid on the inner side of the foot, and os calcis and cuboid on the outer. The inner is part of the anterior sub- astragaloid joint (see p. 605), while the outer has a separate synovial cavity. It should be noted that the movements of turning the toes either in or out take place mainly at the hip-joint; while the turning of one edge of the foot either up or down is a movement that mostly concerns the subastragaloid joints. Club-foot.— It is usual to divide the various forms of talipes, or club-foot, into four main divisions, viz. : (l) T. equinus; (2) T. calcaneus; (3) T. varus; and (4) T. valgus. Four secondary forms result from combinations of these prin- cipal varieties, viz. : T. equino-varus, T. equino- valgus, T. calcaneo-varus, and T. calcaneo-valgus, corresponding to the four positions assumed by the foot at the subastragaloid articulation (see p. 605). 1. Talipes equinus. In this deformity the heel is drawn up, and the patient walks upon the balls of the toes. The contracting muscles are those of the calf, attached to the tendo Achillis. The paralysed muscles are the extensors of the foot. There is plantar flexion and marked inversion of the foot. In a well-marked case the os calcis is much raised, and may even be brought in contact with the tibia. The astragalus is displaced down- wards and projects upon the dorsum. The foot tends to become more and more inverted, until at last the scaphoid may even touch the sustenta- culum. The ligaments of the sole are usually much contracted. 2. Talipes calcaneus. In this form of club-foot the toes are drawn up and the patient walks upon the heel. The contracting muscles are the ex- tensors on the anterior aspect of the limb. The os calcis is rendered more vertical, and the XXV] CLUB-FOOT 609 astragalus becomes so obliquely placed that part of its upper articular surface may project beyond the tibia in a backward direction. 3. Talipes varus. This is the commonest form. Certain features of the fcetal foot are retained in an exaggerated degree. In a well-marked con- genital case there is a threefold deformity : (1) The heel is drawn up by the muscles attached to the tendo Achillis; (2) the foot is inverted by the contraction of the tibialis anticus and posticus; (3) the sole is contracted by the flexor longus digitorum muscle and the shrinking of the plantar fascia and ligaments. The neck of the astragalus is elongated and deflected downwards and inwards to a greater extent than in the normal foot. In the adult the neck of the astragalus is deflected inwards to the axis of its body at an angle of 10° ; in the newly born at an angle of 25° ; and in talipes varus at an angle of 50°. The scaphoid is displaced upwards and inwards, until its inner border often touches the internal malleolus. The three cuneiform bones follow the scaphoid, and the cuboid becomes the lowest bone in the tarsus. The outer border of the cuboid forms an angle with the os calcis, and the tendons of the peroneus longus slip backwards from the groove in the cuboid to lie on the os calcis. The anterior border of the internal lateral ligament is con- tracted and unduly prominent. There is thus a marked degree of inversion. 4. In talipes < valgus the foot assumes perma- nently the position of eversion. The contracting muscles are the two peronei. In a well-markeu congenital case the os calcis is found a little raised and the astragalus is displaced forwards and downwards. The scaphoid is so rotated that its inner part is depressed and its outer raised. The internal portion of the bone forms one of the two projections obvious on the inner side of the foot, the other prominence being formed by the head of the astragalus. The cuboid is found to be a little rotated outwards. The arch of the 610 THE LOWEIl EXTREMITY [Chap. foot is lost, and all those ligaments are stretched that serve to support and maintain that arch. Of the mixed, or secondary, forms of talipes nothing need be said. They are the results merely of a combination of the primary varieties. As trouble is often caused in talipes by pres- sure being brought to bear upon an unusual part of the foot, it is well to note upon what portion of the member the patient treads in the different varieties of the deformity. In varus the " tread " is mainly upon the outer side of the 5th meta- tarsal bone ; in valgus upon the internal malle- olus and scaphoid; in equinus upon the bases of all the toes; in equino-varus upon the base of the little toe ; in equino-valgus upon the base of the great toe; in all forms of calcaneus upon the heel. In cases of extreme and obstinate club-foot wedges of bone are sometimes removed by the operation known as tarsectomy. Thus in talipes equino-varus the base of the wedge will be on the outer side of the foot, and will be mainly repre- sented by the cuboid; the apex will be at the scaphoid. Flat-foot and splay-foot are the names given to a deformity due probably to the yielding of certain ligaments, whereby the arch of the foot is lost and the sole becomes more or less perfectly flat. The foot, at the same time, is abducted, and the outer border is often a little raised, so that the patient walks mainly upon the inner side of the foot. This deformity is met with in those who stand a great deal, and is the direct result of yielding of the muscles which maintain the foot in a position of inversion — especially the tibialis anticus and posticus. It is only when these muscles become exhausted and yield that the ligaments are strained and elon- gated, for it may be accepted as a law that the normal strain at a joint falls on the muscles, the ligaments only coming into action in limiting the extent of ^ movements. The inferior calcaneo- scaphoid ligament is lax in the standing posture; XXV] FLAT-FOOT CdII the weight of the head of the astragalus is then supported by the tibialis posticus (Fig. 125). As is well known, the muscles of the leg and foot become more quickly exhausted when stand- ing than when walking, for in the standing posture the muscles which invert the foot are maintained in a condition of tonus, whereas in walking they have alternate periods of action and rest. Hence in those whose occupations entail prolonged periods of standing, the muscles which maintain the inversion of the foot become ex- hausted — especially the tibialis posticus; they Am 5up. An. LiQAME/NTy Tibialis Anticus v Mid. Cuneiform Int. Cuneiform Jem do AcniLLi s Fl.l.Dicitorum l/IT. AlALLEOLUS Tibialis Post. , SuSTErtT.TALI /lEAD OFASTRACALUS Mr. Calcaaieo Scap* Liq. Tuberosity op5cap/ioid Fig. 125. — Dissection of a flat-foot from the inner side. gradually yield, and the superincumbent weight of the body then falls on the structures which limit eversion of the foot, especially the inferior calcaneo-scaphoid ligament, on which the head of the astragalus then comes torest (Fig. 125). When the weight falls on this ligament it begins to yield; the head of the astragalus is pressed for- wards, downwards, and inwards by the superin- cumbent weight, and the foot beyond becomes, as a consequence, over-extended and turned out (Fig. 125). The os calcis slants inwards, and its anterior end is depressed. The sustentaculum tali, the head of the astragalus, and the scaphoid tubercle 612 THE LOWER EXTREMITY [Chap. form prominences on the inner side of the foot, and may rest on the ground (Fig. 125). The long and short plantar ligaments also, which contribute so much to the maintenance of the arch of the foot, in time yield, and allow of a still greater degree of deformity. There is a stretching also of the deltoid ligament. In neglected cases the distortion is rendered more or less permanent by BCD Fig. 126. — Various forms of foot-prints. A, Of normal foot with high arch. B, „ „ „ also with high arch. C, „ „ „ with low arch . D, „ fiat foot. alterations in the shape of the tarsal bones, and by a contraction of such ligaments as have been relaxed by the deformity. The scaphoid and in- ternal cuneiform become markedly wedge-shaped, with the apices directed to the dorsum of the foot (Fig. 125). The foot being abducted, and its outer border a little raised, the peronei muscles become relaxed, shortened, and contribute to the perma- nency of the disorder. It will be understood that XXV] FRACTURES OF TARSAL BONES 613 the abnormal pressure brought to bear upon the various tarsal bones and articulations will cause severe pain to be often associated with this affec- tion. The calf muscles waste, owing to the arch of the foot having lost its rigidity and being no longer able to support the weight of the body. Imprints of normal feet vary much in form {see Fig. 126). Dr. Lovett, of Boston, is of opinion that the feet which come in contact with the ground at only two parts — at the heel behind, and along the pad of the foot in front— are those which are most prone to break down (Fig. 126, a). In flat foot the inner border of the foot also comes in contact with the ground, so that the area be- tween the heel, the plantar pad, and the outer margin of the foot, left blank in the normal im- print, become partially or completely filled up (Fig. 126). It may be noted that the medio-tarsal joint, which is so conspicuously involved in the distor- tion, is supplied by the anterior tibial, musculo- cutaneous, and external plantar nerves. The tarsal bones, owing to their spongy char- acter, are readily broken by direct violence, as in severe crushes. The soft parts that cover these bones being scanty upon the dorsal aspect of the foot, it follows that these accidents are often compound and associated with much lacera- tion of the integuments. The tarsal bone the most frequently fractured is the os calcis. This bone may be broken by a fall upon the heel, and in many instances has been the only one fractured by such an accident. A few cases have been recorded of fracture of the calcaneum by muscular violence, the muscles producing the lesion being those attached to the tendo Achillis. Thus, Sir A. Cooper reports the case of a woman, aged 42, in whom a large fragment of the posterior part of the os calcis was torn away by the muscles and drawn some 2j inches away from the heel. The accident was caused by her taking a false step. Abel has 614 THE LOWER EXTREMITY [Chap. collected three cases of fracture of the susten- taculum tali. He believes that this injury may be produced by falls upon the sole or by extreme inversion of the foot, whereby the astragalus is forced violently against the process. The astragalus alone may be broken by a fall upon the feet, and such accidents are often associ- ated with fractures of both that bone and the os calcis. It must be noted, however, that in a fall, when the patient alights upon the feet, the tibia and fibula are much more likely to be broken than are the tarsal bones, since the bones of the leg transmit the weight of the body directly, whereas that weight is much diffused and broken up when passing through the foot with its many bones and joints. The metatarsal bones and phalanges are nearly always broken by direct violence. I had, how- ever, under my care at the London Hospital a man who had broken the shafts of the three outer metatarsal bones by simply slipping off the edge of the curb. Since the introduction of X-rays as a means of diagnosis, fractures of the metatarsal bones, especially of the fifth, and of the phalanges, are found to occur not infrequently, and often as the result of a movement or accident which seems totally insufficient to produce such lesions. With regard to the luxations of the foot not yet considered, it may be said that the cuboid is never dislocated alone. Walker reports a case of dislocation of the scaphoid alone, that structure being quite separated from the astragalus and cuneiform bones. The accident was brought about by alighting upon the ball of the foot when jump- ing, and the little bone was found projecting on the dorsum. Mr. Bryant has mentioned an in- stance of dislocation of the scaphoid inwards. As a rule, however, this bone when displaced is dislocated along with the astragalus. Of the cuneiform bones the one most often luxated alone is the internal. The attachments of the tendons of the tibialis anticus and peroneus XXV] OSSIFICATION OF TARSUS 615 longus about the internal cuneiform and first metatarsal bones render it common for the latter to follow its tarsal colleague when dislocated. Mr. Luke has recorded a case of incomplete luxa- tion of all three cuneiform bones upwards, and at least three cases have been described of disloca- tion of the internal bone upwards and backwards, together with a like displacement of all the meta- tarsals. One or more of the metatarsal bones may be luxated, or the entire series may be displaced upwards, downwards, inwards, or outwards, the first-named lesion being the most common. In rarer instances, one bone has been thrown in one direction and its fellow or fellows in another. Ossification of the tarsus. — At birth the tar- sus is mainly cartilaginous. Ossification begins in the os calcis in the sixth month and in the astragalus in the seventh month of foetal life. The centre for the cuboid appears at birth, and in the scaphoid, the last to ossify, in the third year. It is not until puberty that the cartilage of the tarsal bones is completely ossified. Like the epiphyses of long bones the tarsal bones are en- tirely formed in cartilage, there being no peri- osteal formation. Hence it is possible, as Ogston has shown, to enucleate the ossific centres from the tarsal bones of children who are the subjects of club-foot and by remodelling the cartilaginous capsules left behind, obtain new ossifications of a more normal form. Dislocation of the proximal phalanx of the great toe is often very difficult to reduce, as is also the case in the corresponding luxation of the thumb. When the displacement is dorsal, the difficulty is probably due to the sesamoid bones, which are embedded in the glenoid ligament or fibrocartilaginous^ plate. " Like the glenoid liga- ments, the sesamoid bones are much more firmly connected with the phalanx than with the meta- tarsal bone, and thus get torn away and shut back behind the head of the metatarsal bone; or 616 THE LOWEE EXTREMITY TChap. Fig, 127, — iOblique antero- posterior section of foot, to I show the synovial cavities of the tarsus. (Rudinger.) 1, Tibia ; 2, fibula ; 3, astragalus ; 4, os calcis ; 5, external lateral ligament ; 6, internal lateral ligament ; 7, interosseous liga- ment between astragalus and os caleis : 8, head of astragalus ; 9, scaphoid ; 10, 11. and 12, the thi-ee cuneiform bones ; 13, cuboid. it may be that the sesamoid bones, re- taining their con- nexions with the lateral ligaments of the joint as well as with the short flexor tendons, are separated from one another, and so allow the head of the meta- tarsal bone to pass forwards, and thus become nipped, as it were, in a button-hole between them " (Sir Henry Morris). A partial dislocation of the proximal phalanx outwards on the head of the metatarsal bone of the great toe constitutes the con- dition known as hallux valgus. The inner lateral liga- ment of the joint is elongated, while the outer is contracted. In hallux rigidus this joint is slightly flexed and rigid, due probably to a reflex contraction of the flexor brevis hallucis. The second toe is com- monly longer than the others, and is more liable to assume the form known as " hammer toe.' ' The proximal phalanx in XXV] SYME'S AMPUTATION AT ANKLE 617 such a form is extended, while the middle is strongly flexed. The condition is commonly in- herited, and is due to a contraction of the glenoid and lateral ligaments of the proximal phalangeal joint. The extensor tendon is also contracted. There are six synovial cavities in the foot, excluding that of the ankle-joint, viz. one for the posterior subastragaloid joint, a second for the anterior subastragaloid, a third between the os calcis and cuboid, a fourth between the latter bone and the two outer metatarsals, a fifth for the joint between the inner cuneiform and first metatarsal bones, and a sixth for the remain- ing articulations (Fig. 127). These synovial cavities tend greatly to diffuse disease among the various bones of the foot when once one bone has become inflamed. The best position, therefore, for bone disease, with reference to the question of exten- sion, w°uld be in the hinder parts of either the os calcis or astragalus, and one of the worst posi- tions would be assumed by disease involving the scaphoid bone. Syme's amputation at the ankle (Fig. 128). — In the heel-flap are cut the integuments, the external saphenous nerve and vein, the peroneus longus, peroneus brevis, tibialis posticus, flexor longus digitorum, flexor longus hallucis, tendo Achillis, points of origin of the flexor brevis digitorum and of the two abductor muscles, and the internal and external plantar arteries and nerves. In the dorsal flap are cut the integuments, tibialis anticus, extensor communis digitorum, ex- tensor proprius hallucis, peroneus tertius, anterior tibial vessels and nerve, musculo-cutaneous nerve, and internal saphenous nerve and vein. The posi- tion of the principal structures divided is shown in Fig. 128. It is not usual to dissect up any of the muscular tissue of the sole, as shown in Agatz's plate. It should be noted that the integuments of the heel derive their blood supply, which is very free, mainly from the external calcaneal branch of the posterior peroneal artery on the u* 618 THE LOWER EXTREMITY [Chap. -Syme's amputation. {Agatz.) Tibia ; b, fibula ; e, tibialis anticus ; d, extensor proprius hallucis ; e, extensor communis digitorum ; /, peroneus tertius ; g, flexor lon- gus hallucis ; 7), tibialis posticus ; f, flexor longus digitorum ; j, pe- roneus brevis; k, peroneus lon- gus ; I, tendo Achillis ; m, some muscles of the sole that are not usually left in this operation ; n, anterior tibial vessels ; o, poste- rior tibial vessels ; p, posterior tibial nerve. outer side, and the internal calcaneal from the external plantar on the inner. If the heel in- cision is carried sufficiently far back to divide the trunk of the posterior tibial artery, the heel flap is deprived of the last-named source of blood supply. The posterior tibial ar- tery bifurcates upon a line drawn from the tip of the inner malleolus to the cen- tre of the convexity of the heel. The nerves supply- ing the integuments of the heel are the calcaneal branch of the external saphe- nous and the cal- caneal and plantar cutaneous twigs from the posterior tibial. In Pirogoff's am- putation the parts divided in the an- terior flap are the same as in Syme's operation. In the heel or sole flap the same structures also are cut as in the corre- sponding flap in a Syme, with the exception that the tendo Achillis is not divided, the flexor brevis digitorum, XXV] CHOPART'S AMPUTATION 619 abductor hallucis, abductor minimi digiti, and flexor accessorius are divided more extensively, and the plantar vessels are cut farther from the bifurcation. Chopart's operation is an amputation at the mediotarsal joint (Fig. 129). In the dorsal flap are cut the integuments, the extensor communis and brevis digitorum, ex- tensor proprius hallucis, tibialis anticus, pero- neus tertius and brevis, the mus- culo - cutaneous, anterior tibial, and two saphen- ous nerves, the dorsal artery, and the dorsal plexus of veins. In the plantar flap are found divided the in- teguments, plan- tar fascia, flexor brevis digit- orum, abductors of the great and little toes, flexor accessorius, and tibialis posticus tendon. If the flap be well dis- sected up, parts of the short flexors of the great and little toes, the abductor hallucis, and transversiis pedis will be found cut in the flap. The tendons of the long flexors of the digits and great toes, the peroneus longus, and the plantar vessels and nerves are also divided (Fig. 129). -Chopart's operation. (Agatz.) a, Astragalus ; b, os calcis ; c, extensor pro- prius hallucis ; d, tibialis anticus ; c, ex- tensor communis digitorum; /, peroneus longus ; g, adductor minimi digiti ; //, flexor brevis digitorum ; i, flexor longus digitorum ; j, abductor hallucis ; k, flexor longus hallucis ; /, dorsalis pedis artery ; m, internal plantar artery ; ft, external plantar artery. 620 THE LOWER EXTREMITY [Chap. Lisfranc's operation, or amputation through the tarso-metatarsal line of joints (Fig. 130). — In the dorsal flap the same structures are divided as are cut in the corresponding flap in Chopart's amputation. In the plantar flap also the parts divided are the same as in that procedure, with the exception that the flexor accessor ius and the tendon of the tibialis posticus escape section. The articulations be- tween the three outer metatarsals and the corresponding tarsal bones form a line sufficiently straight to be traversed by the knife in one cut when once the blade has been introduced. The joint also be- tween the first meta- tarsal and internal cuneiform bones is in a straight line and readily opened. The most difficult part of the disarticulation concerns the separa- tion of the second metatarsal bone, which is deeply lodged between the tarsal segments. The chief bond of union between this bone and the tarsus is effected by a strong interosseous ligament that passes between it and the internal cuneiform. In Fig. 130 the knife is placed in the position re- Fig, 130. — Lisfranc's operation. {Agatz.) a, &, c, Inner, middle, and outer cunei- form bones ; d, cuboid ; e, f, the metatarsal bones ; g, tibialis an- ticus ; h, extensor proprius hal- lucis ; i, extensor communis digitorum ; j, extensor brevis digitorum ; k, extensor tendons ; I, dorsalis pedis artery. XXV] NERVE SUPPLY OF LOWER LIMB 621 quired to divide that ligament, and in Fig. 131 the ligament is shown. In the subastragaloid amputations a disarticu- lation is effected at the subastragaloid articula- tions. The astragalus is the only bone of the foot left behind, and forms the summit of the stump. JVerve supply of the lower limb. — In Fig. 132 is shown the cutaneous nerve supply of the inferior extremities on both the anterior and Mid. Cuneiform Int. Cuneiform 2nd Metatar. Fig. 131.— The ligament of Lisfranc. (After Poirier. the posterior aspect, and in Fig. 133 are seen the cord segments from which they are derived. Paralyses of the lower limbs are common, but are more often due to some lesion in the inferior segment of the cord than to damage received by any one individual nerve. Cases, however, are recorded where a single trunk has been injured and a limited form of paralysis has followed in consequence. Paralysis of the anterior crural nerve has been caused by injuries to the lower part of the V 9 I Fig, 132,— Cutane- ous nerve supply of lower limb. 10 Anterior aspect.— 1, Ilioinguinal ; 2, genito-crural ; 8, external cuta- neous ; 4. middle cutaneous ; 5, internal cutaneous ; 6, patellar plexus ; 7 branches of external popliteal ; 8, internal saphenous ; 9, musculocutaneous ; 10, external saphenous ; 11, anterior tibial. Posterior aspect— I, 2, and 3, Small sciatic; 4, external cutaneous ; 5, internal cutaneous ; 6, internal saphenous ; 7, branches of ex- ternal popliteal ; 8, short saphenous :i 9, posterior tibial; 10, in- ternal saphenous ; 11, internal plantar ;'12 ; external plantar. 622 Fig. 133. — Showing the skin areas in the lower extremity supplied by the lumbar and sacral segments of the spinal cord. (After Head.) On each area is indicated the segment of the cord by which it is supplied. For the nerves supplying each area see Fig. 132. 623 624 THE LOWER EXTREMITY IChap. vertebral column implicating the cauda equina, by fractures of the pelvis, by tumours of the pelvis, by psoas abscess, by fractures and dis- locations of the femur, and by stabs in the region of the groin. In this nerve lesion the patient is unable to flex the hip or to raise the body from the recumbent position (ilio-psoas). The adductor muscles : may simulate the action of the flexors of the hip, but it will be observed that they rotate and adduct the thigh as well as flex it. The power of extending the leg at the knee is lost (quadri- ceps extensor cruris) ; the function of the sar- torius is destroyed and that of the pectineus im- paired. Sensation is impaired in parts supplied by the internal and middle cutaneous nerves and the long saphenous nerve. Paralysis of the obturator nerve alone is a rare condition, although it may be found associ- ated with a like lesion of the preceding trunk. It may be brought about by the pressure exer- cised upon the nerve in cases of obturator hernia and by the foetal head during delivery. The muscles implicated are the adductors, gracilis, and external obturator. The patient is unable to press the knees together, or to cross the # legs. Rotation outwards is difficult, but sensation is scarcely affected in the skin supplied. Paralysis of the internal popliteal nerve. — There is inability to flex^ the ankle and to flex the toes (flexor longus digitorum, flexor proprius hallucis, tibialis posticus, gastrocnemius, and soleus). The patient is unable to stand upon the toes, owing to loss of function in the two last- named muscles. t The power of inverting the foot is impaired (tibialis posticus), and lateral move- ment in the toes is lost owing to paralysis of all the small muscles of the sole. Sensation is im- paired over the plantar aspect of the toes, the sole, and in part of the lower half of the back of the leg. In paralysis of the external popliteal nerve the action of the muscles on the front of the leg is XXV] NERVE SUPPLY OF LOWER LIMB G25 lost. The foot hangs down and the toes catch the ground in walking. The foot can be neither dorsi- flexed nor everted (extensor communis digitorum, extensor proprius hallucis, peroneal muscles). Adduction is imperfect, owing to paralysis of the tibialis anticus. Extension of the toes is only possible to the slight extent effected by the interossei. The arch of the foot becomes flattened owing to loss of the support furnished by the peroneus longus. Sensation is impaired over the front and outer side of the leg and on the dorsum of the foot, and also over some part of the back of the leg, owing to paralysis of the communicans peronei. The fibres destined for any particular muscle are not assorted in one fasciculus until near their point of exit from the nerve trunk ; hence a nerve trunk such as the internal popliteal may be partly divided without any apparent effect. This cir- cumstance is taken advantage of in cases of in- fantile paralysis. In a case where the external popliteal is affected, action of the extensor mus- cles may be restored by suturing that nerve to a slip partially separated from the internal popliteal. When the great sciatic nerve is paralysed, there will be, in addition to the loss or function in the two preceding nerves, an inability to flex the knee owing to paralysis of the hamstrings, while rotation of the limb may be impaired by loss of power in the quadratus femoris and ob- turator internus. Mr. Sherren found that the knee may still be flexed in such cases through the action of the gracilis, and that sensation was completely lost in only part of the sole of the foot. A knowledge of the segments of the cord from which the nerves of the lower limb arise often assists g the surgeon in localizing certain lesions. Section of a nerve root, as may happen in fracture of the spine, or destruction of its centre in the spinal cord, gives rise to paralysis (520 THE LOWER EXTREMITY l[Chap. XXV in a definite group of muscles and anaesthesia of a certain area of skin. The skin areas supplied by the lumbar and sacral segments are shown in Fig. 133, and these segments, accord- ing to Kocher, innervate the following groups of muscles : Third lumbar, the psoas, iliacus, pec- tineuSj sartorius and adductors; fourth lumbar, quadriceps extensor cruris; fifth lumbar, gluteus medius and minimus, tensor vaginae femoris and hamstrings; first sacral, gluteus maximus, short external rotators of the hip-joint, peronei, exten- sors of the toes and flexors of the ankle; second sacral, gastrocnemius, soleus, long flexors of the toes and extensors of the ankle-joint and muscles of the sole. PART VI THE SPINE AND SPINAL CORD CHAPTER XXVI THE SPINE The vertebral column combines in a remarkable way many very different and complicated func- tions. It acts as the central pillar of the body, and as the column that supports the weight of the head. It connects the upper and lower seg- ments of the trunk. It gives attachments to the ribs. It has the property of mitigating the effects of shocks that' are transmitted from various parts of the body. It permits, to a wonderful degree, of a number of most complicated movements; and, lastly, forms a solid tube for the reception of the spinal cord. It owes much of its elasticity, and of its power of breaking up divers forces communicated to it, to its curves. Of the four curves, two, the dorsal and sacral, are primary and are due to the forma- tion of the thoracic and pelvic cavities, depending mainly upon the shape of the bones. The other two, the cervical and lumbar, are compensatory curves, and depend # mainly upon the shape of the intervertebral discs. The dorsal and sacral curves appear in fcetal life ; the lumbar and cervical curves appear after birth, following the f>27 628 THE SPINE AND SPINAL CORD [Chap. assumption of the erect position. The infant's spine appears straight. The only marked curve seen in the back of the young child is a general curving of the column backwards, a kyphosis. When the infant is first encouraged to sit erect, this is the outline assumed by the spine, and in some weakly children, and especially in those afflicted with rickets, this curvature is often very pronounced. The intervertebral discs, twenty- three in number, make up nearly one-fourth of the entire length of the spine. If the discs be removed, and the vertebrae be articulated in the dry state, the cervical and lumbar convexities almost dis- appear, and the column tends to present one great curvature, the concavity of which is forwards, and the most marked part of which corresponds to a point just below the middle of the dorsal region. This somewhat resembles the curve seen in the spines of the aged, and in such individuals it may be to no small extent due to the shrinking of the intervertebral discs. It is by means of the discs that the move- ments of the spine are in the main permitted, and it will be found that they are most developed in regions where most movement is allowed. They act also as springs in giving elasticity to the column, and in economizing muscular action, while at the same time they play the part of buffers in modifying the effect of shocks trans- mitted along the spine. Although the motion permitted between any two individual vertebrae is not extensive, yet the degree of movement capable of being exercised in the column as a whole is considerable. While lateral movements and those of flexion and ex- tension are restricted in the dorsal region, those of rotation are free ; hence scoliosis of the spine is most marked in this region. Movements from back to front (flexion and extension) and from side to side (lateral flexion) are freest in the cervical, dorso-lumbar, and lumbar regions. From a surgical point of view the weakest part of XXVI] THE ERECT POSTURE 629 the spinal column is between the 9th dorsal and 3rd lumbar vertebrae. Here side-to-side and back- to-front movements occur most freely ; above this region the spine is supported by the thorax ; below the intervertebral discs are larger and stronger, and the supporting ligaments and muscles better developed. It is impossible to insist too strongly on the fact that the muscles of the back and trunk are the sole agents in maintaining- the spine erect. The moment they are thrown out of action the spinal column loses its rigidity and collapses. All four groups of muscles which act on the spine are concerned : the extensors (erector spinas) ; the flexors (rectus abdominis, longus colli, psoas) ; the lateral flexors (erector spinas, quadratus lum- borum, internal and external oblique, intercos- tals, and levatores costarum); rotators (external and internal oblique, multifidus spinas, semi- spinalis, intercostals, and levatores costarum). By these muscles the vertebras are maintained balanced on their intervertebral discs, one above the other. The ligaments are slack, and the sur- faces of the articular processes are in only light contact. When the muscles approach exhaustion, owing to prolonged maintenance of the erect pos- ture, partial relief may be obtained by allowing a certain degree of rotation and lateral flexion to take place. Thereby the articular processes are brought into firm contact, the ligaments become somewhat tightened, and a certain degree of pas- sive support is obtained. School children, for instance, after sitting some time with their bodies erect, place an arm on the desk and rotate the body until the vertebras are partly locked. In this posture the muscles are rested, but if the position be much indulged in, the muscles become weakened in their action, and the spine may assume permanently a partial scoliosis. Scoliosis. — In very few people do the spines of the vertebras lie in a perfectly straight line down the back. There is commonly a slight de- 630 THE SPINE AND SPINAL COED [Chap. gree of lateral curvature. If the pelvis be tilted laterally, as when the limbs are unequal in length, a compensatory lateral curve is produced. In scoliosis, lateral curvature is combined with a rotation of the vertebrae, the spinous processes turning to one side of the median line and the bodies to the opposite. It is a disease of ado- lescents, due to a weakness of the spinal muscles, which are unable to maintain the vertebrae in the position necessary for the erect posture. Kach vertebra is provided with three levers, a posterior (the spinous process) and two lateral (the transverse processes and attached ribs). The erector spinae acts on the lateral levers; the multifidus spinae and muscles for the upper ex- tremity on the posterior. It is through train- ing these muscles by suitable exercises that the vertebrae can be restored to, and maintained in, their normal positions. The ribs form the most powerful spinal levers ; in exercises to restore deformities of the spine this should be kept in mind. All the respiratory muscles act indirectly through the costal levers on the spine; hence respiratory exercises are suitable for the treat- ment of postural defects. Dr. Halls Dally has shown that in all forms of breathing, and es- pecially in forced respiration, spinal movements are always present. Sprains of the vertebral column. — The many joints and ligaments of the Dart, and the varied and violent movements to which it may be exposed, render it very liable to be the seat of sprains. These injuries, however, cannot reach any; great magnitude, for so closely are the in- dividual vertebrae articulated, that any force severe enough to produce other than slight tearing of the ligaments will tend to cause a fracture or dislocation of the bones. Sprains are most commonly met with in the cervical and lumbar segments of the spine. This localization is due to the mobility of these^ parts, and to their tendency to diffuse any violence XXVI] SPRAINS OF VERTEBRAL COLUMN 631 transmitted to them, and so to render it more general. For it is to be noted that the more localised an injury, the more likely it is to pro- duce a fracture or dislocation rather than a sprain. In the cervical region, also, the tendency to sprain is increased by the near articulation of the column with the head, and the possibility of any violence applied to the skull being transmitted to the spine. Since the introduction of Rontgen rays in the diagnosis of such injuries it has become apparent that many lesions formerly regarded as sprains are really fractures of the body of the vertebra or of the neural arch (Sherren). Sprains of the spine are not apt to be asso- ciated with the external evidences of ecchymosis, since between the skin and the column there inter- vene not only many layers of muscles, but also dense expansions of fascia. It has already been pointed out that sprains in the loin, produced by severe bending forwards of the column, may be associated with some damage to the kidney and consequent hematuria (p. 430). A sprained back is often the seat of a con- siderable degree of pain and stiffness, that per- sists long after the immediate effects of the lesion must have passed away. Such a condition may be understood by noticing that the column presents a vast number of separate articulations, each provided with cartilage, synovial membrane, and capsular ligaments. These joints have no quali- ties that exempt them from the common evils incident to sprains of more superficial articula- tions; and there is little doubt that the long-felt pain and inconvenience often depend upon some synovitis of the vertebral joints. In a few cases this synovitis has gone on to suppuration, and in one instance at least the pus so formed found its way into the spinal canal and induced some mis- chief in the cord. G32 THE SPINE AND SPINAL COED [Chap . Fractures and dislocations of the spine.— The effects of violence applied to the column are much diminished by the general elasticity of the spine, by its curves, and by the circumstance that it is composed of a number of separate segments. Each vertebra meets the one immediately above or below it at three points of contact, the body and the two articulating processes. The bodies are separated by the intervertebral disc, which acts as an excellent spring or buffer in modifying the effects of violence. The articulating processes are more or less wedge-shaped, the thin edge of one being applied to the base of the other. When a force that tends to compress the vertebrae together is applied to the column, the bases of the two wedges are brought into more and more close rela- tion, and thus an increasing resistance is offered to the compressing power. The parts of the spine most liable to injury are (1) the atlan to-axial, (2) the cervico-dorsal, and (3) the dorso-lumbar. In the atlanto-axial region the parts not only enjoy a very considerable degree of movement but are very directly influenced by many forms of violence applied to the head. In the two other regions it will be noted that a flexible part of the spine joins a comparatively rigid segment of it, and thus violence applied to the column in either of these districts is apt to be concentrated rather than diffused. The sternum and ribs act as a splint to the dorsal part of the column. The mechanism is in a way illustrated by the circumstance that a fishing-rod when it snaps commonlv breaks near a joint, that is to say, at a spot where a flexible segment of the rod meets a less elastic portion. In the dorso-lumbar region, moreover, the vertebrae, although they have to support almost as much weight as have those of the lumbar region proper, are yet dispro- portionately small in size. Being placed, also, near the middle of the column, they can be in- fluenced on all sides by a powerful amount of leverage. The gravity of all injuries to the spine XXVI] INJURIES TO THE SPINE 633 depends upon the risk of damage to the cord en- closed in the column. Apart from this complica- tion, fractures and dislocations in this region are apt to do well, and, if the patient survive, the former lesions nearly always heal readily. The position of the cord within the vertebral canal and the arrangement of its membranes are such that it presents many facilities for escaping injury from violence. These will be dealt with subsequently in speaking of the cord itself. It may, however, be noted here that the construction of the vertebrae, and their relation to one another, are of a character to afford much protection to the cord, even in cases where they themselves are ex- tensively damaged. " Being lodged in the centre of the column, it (the cord) occupies neutral ground to forces which might cause fracture. For it is a law in mechanics that when a beam, as of timber, is exposed to breakage, and the force does not exceed the limits of the strength of the material, one division resists compression, another laceration of the particles, while the third, between the two, is in a negative condi- tion" (Jacobson, Holmes's "System"). Now, it happens that fractures of the spine are most often due to violence that bends the column forwards. The anterior segment, in such a case, will be sub- ject to compression, the posterior to laceration, and the intermediate portion will be in a neutral condition. When the spine is examined, it will be found that its anterior part, composed of the large cancellous bodies, is excellently adapted to resist the effects of compression, while its pos- terior parts, composed of slighter and more com- pact bones and surrounded by many strong liga- ments, are well arranged to resist the effects of a tearing force. The spinal cord, situated between these two divisions, occupies the position of least danger. The vertebrae may be fractured without being dislocated, but a dislocation without a fracture is rarely possible. 634 THE SPINE AND SPINAL CORD [Chap. It would appear, indeed, that a luxation of the spine, with no fracture of the bone, cannot occur in either the dorsal or lumbar regions. Mr. Jacobson, in the essay above referred to, writes : " I believe I am correct in stating that there is no case recorded, and thoroughly verified, in recent years, of dislocation of the lumbar or dorsal ver- tebrae unaccompanied with any fracture of the body, transverse or articular processes." Dislocation without fracture is met with in the cervical spine. When it occurs it most often involves the fifth vertebra, which, with the rest of the column above it, is displaced forwards and downwards. Luxa- tions in other directions have been noted, but they are extremely uncommon. The possibility of luxation in the cervical region without fracture is explained by the small size of the vertebral bodies, the obliquity of their articular processes, and the relatively slight opposition they offer to displacement when compared with like processes in the other parts of the column. The luxation is usually bilateral and incomplete, and the result of a forcible bending of the head and upper part of the spine forwards and downwards. When situated high up the displacement may be appre- ciated by an examination of the part through the pharynx. The degree of deformity may be slight, and the spinal injury overlooked. The paralysis below the level of the dislocation may be in- complete; so that a diagnosis of injury to the brachial plexus may be made when it is really one of the spine and cord (Sherren). In the complete bilateral dislocation the cord is usually hopelessly crushed. These^ luxations have been reduced by forcible extension, although the cir- cumstances under which such a procedure is advisable are neither frequent nor very distinctly marked. Since, in severe injuries, dislocation and frac- ture are so usually associated, it is common to deal with these lesions under the title of fracture- dislocation. These may be due to (l) in- XXVI] FRACTURE-DISLOCATIONS OF SPINE G35 direct, or (2) direct violence. (1) The injuries from indirect violence are by far the more com- mon. They are due to a violent bending of the head, or of the spine above the seat of lesion, for- wards and downwards. Thus, the cervical spine has been more than once broken by a " header " into shallow water; while the dorsal vertebrae have been fractured and displaced by the acute bending of the column produced by a heavy sack falling upon the back of the neck. This form of injury is most commonly met with in the cervical and upper dorsal regions. These parts of the column possess great mobility, the bodies that compose them are not large, and are influenced by violence applied to the head. In a well-marked case there is some crushing of the vertebrae involved, and the usual deformity de- pends upon the sliding of the centrum above downwards and forwards upon the centrum below. Complete displacement of any two vertebrae from one another is prevented by a locking of the pos- terior processes. ^ In some cases the luxation is complete, a condition that is least frequently met with in the lumbar spine. In the cervical and dorsal regions, the parts, after the dislocation, may often be returned to their normal position ; but in the loins this re- placement is usually impossible, owing to the lock- ing of the large and powerful articular processes. In the neck the laminae and spines may be frac- tured, while the articulating processes, being broad and nearly horizontal, usually escape, even when there is much displacement of the parts. In the dorsal spine the laminae and articular pro- cesses are always torn when displacement occurs. In the lumbar region the articular processes usually escape fracture, although they are vio- lently torn asunder. In all cases there is more or less laceration of the intervertebral discs, and the supraspinous, interspinous, and capsular liga- ments are torn, as are also the ligamenta subflava. When the bodies are much crushed and displaced 636 THE SPINE AND SPINAL CORD [Chap. the anterior and posterior common ligaments are commonly ruptured. (2) In the fracture-dislocations due to direct violence the lesion may be at any part of the spine. Some form of direct violence is applied to the back, and the column tends to become bent backwards at the spot struck. In the previous class of injuries it will be noted that the anterior segments of the vertebrae suffer compression, while the posterior suffer from the effects of laceration and a tearing asunder of their parts. In lesions due to direct violence the circumstances of the in- jury are reversed; the posterior segments tend to be crushed together, while the bodies on the front of the spine are separated. Much displacement is very rarely met with in this form of accident. To produce separation of the vertebrae the violence must be extreme, and as a rule the force expends itself upon a crushing of the hinder portions of the spinal segments. It follows from this that injury to the cord is less common and less severe in lesions due to direct violence than in those due to indirect violence. In the atlanto-axial region the atlas and occipital bone have been dislocated from one another by direct violence, although the most fre- quent lesion is a dislocation of the former for- wards upon the axis, a lesion usually, if not always, associated with fracture of the odontoid process. The transverse process of the atlas can be felt between the mastoid process and the jaw when it is in normal position (E. Corner). The spinous processes may be broken off as a result of well-localized blows. The prominent spines in the lower cervical region and the long processes of the dorsal tract of the column are those that usually suffer. The lumbar spines are less freauently broken, being comparatively small and well protected by the great muscles of the back. The transverse processes and laminae can scarcely be fractured alone. In great exertions, XXVI] LAMINECTOMY 637 as in lifting or carrying heavy weights on the back, the psoas and quadratus lumborum may actually fracture the transverse processes of the lumbar vertebrae to which they are attached. In several instances of fracture-dislocation and of fracture alone the spine has been trephined, or rather portions of the laminae and spinous pro- cesses have been resected (laminectomy). By this means the spinal canal has been freely opened up, effused blood has been allowed to escape, and the cord has been freed from pressure. The laminae are divided as near the transverse process as pos- sible, and the tough ligamenta subflava require careful division. The column is reached through a median in- cision, and the great muscular masses are cleared from the spinous processes and laminae on either side. The wound being nearly median, the bleed- ing is not excessive. The dorsal spinal plexus of veins lies along the spines and over the laminae. On the deep surface of the laminae lie the pos- terior longitudinal spinal veins This operation has also been carried out with success in cases of paralysis due to the pressure upon the cord by displaced bone or inflammatory exudations in caries of the spine (Pott's disease). It has to be noted, however, in the last-named class of case, that the condition exhibits a ten- dency to spontaneous cure. CHAPTE11 XXVII THE SPINAL CORD The spinal cord is, in the adult, about 18 inches in length, and extends from the lower margin of the foramen magnum to the lower edge of the body of the first lumbar vertebra. In some cases it ends at the second lumbar, and in other instances at the last dorsal vertebra. It is to be noted also that in flexion of the spine the cord is a little raised. When the body is bent and the arms are stretched out the lumbar part is raised 10 mm. In the earlier months of total life the medulla spinalis occupies the whole length of the verte- bral canal, but after the third month the canal and lumbar and sacral nerves grow so much faster than the cord, that by the time of birth it reaches no farther than the third lumbar ver- tebra. It is obviously a great advantage, in cases of injury, that the spinal cord does not occupy that part of the vertebral pillar which joins the base of the column, and which permits not only of considerable movement, but is liable also to frequent wrenches and strains. It is important to recollect that although the cord itself ends at the spot indicated, the dura mater, the arachnoid, and the collection of cerebro-spinal fluid extend as far as the third piece of the sacrum (Fig. 135). Injuries inflicted, therefore, upon the spine as low downas this latter point may cause death by inducing inflammation of the meninges. The cord in the dorsal region measures about 10 mm. from 638 Chap. XXVII I SPINAL CORD 639 side to side, and 8 mm. in the anteroposterior direction. The cervical enlargement is largest opposite the fifth or sixth cervical vertebra, where it measures about 13 mm. from side to side. The greatest part of the lumbar enlargement is opposite the twelfth dorsal vertebra, where its lateral measurement is about 12 mm. ■Int. Art. Fig. 134, — Section through spinal cord, membranes, and spinal canal, a.r., at origin of anterior root ; p.r., at origin of posterior root ; s.p., septum posticum ; p.m., pia mater; l.d.. ligamentum denticu- latum. The arachnoid (arach.), dura mater (dura m.), and sub- arachnoid space are shown. The spinal dura mater is a strong and sub- stantial membrane, and between it and the walls of the vertebral canal a considerable space exists, occupied by loose areolar tissue and a plexus of veins (Fig. 134). It is tough, and may remain undamaged when the cord is completely severed by a crushing force. It will be readily understood that injury and inflammation of the meninges, as 640 THE SPINE AND SPINAL CORD [Chap. results of lesions applied to the spine, are much less frequent than are like complications after injuries to the skull. The looseness of the spinal dura mater, its freedom from any but slight and occasional attachments to the bone, and the space around it in which effusions can extend with little possibility of becoming limited, will explain the rarity in the spine of those complications which follow upon depressed bone and extravasations of pus and blood in connexion with the cfura mater within the skull. The plexus of thin-walled veins that occupies the interval between the theca and the bones may prove a source of extensive haemor- rhage in cases of injury to the column. The blood so poured out tends to gravitate to the lowest part of the canal, and when sufficient in quantity may produce pressure effects upon the medulla spinalis. Over the arches at the posterior aspect of the vertebrae is situate a plexus of vessels (the dorsal spinal veins) that receives blood from the muscles and integuments of the back. These vessels com- municate through the ligamenta subllava with the venous plexuses within the spinal canal, and by means of this communication inflammation from without may be conducted to the theca of the cord. Thus spinal meningitis has followed upon deep bed-sores, and upon suppurative affections situated in the immediate vicinity of the spinal laminae. Within the dura mater are two spaces, the subdural and the subarachnoid, as in the skull (see p. 34). The arachnoid is closely applied to the dura mater, the subdural being merely a potential space, while the subarachnoid is exten- sive (Figs. 134 and 135), and occupied by cerebro- spinal fluid which surrounds the cord, and is continuous with the great subarachnoid spaces at the base of the brain (Fig. 9, p. 35). By means of this open communication inflammatory affections may readily spread from the cord to the brain. Into thesa spaces blood may be ex- XXVII] LUMBAR PUNCTURE 641 UBARACnnOiD 5PACfe travasated in cases of injury. Instances have been recorded where the theca has been opened by a wound, and the cerebro-spinal fluid has escaped in large quantities. The fluid normally contains 0*05 per cent, of albumin, but if the mem- branes are inflamed the percentage may be double that amount. In certain conditions the pressure of the fluid may rise to such an extent as to cause death. In normal conditions the fluid is absorbed at any pressure above that of the surround- ing veins (Hill). In the recumbent posture the pressure should support a column of water 2 inches high. In disease it may rise to ten times that amount. The pressure may be relieved by a lumbar puncture, made by thrusting a needle 8-10 cm. long into the subarachnoid space in the lumbar region of the spine. A point is selected between the third and fourth lumbar spines, exactly in the middle line, because here the interlaminar spaces are widest and the danger of wounding blood-vessels and nerve-roots is less than if a lateral point is selected. The interlaminar space is much in- creased when the spine is bent forwards. The needle perforates the ligamentum subflavum be- tween the laminae. Convulsions follow if the pres- sure be reduced much below the normal. At this level the cord cannot be injured, but the needle v Fig. 135. — Vertical section of the lower part of the spinal column to show the position and extent of the subarachnoid space. The arrow shows the point for lumbar puncture. 642 THE SPINE AND SPINAL CORD [Chap. I — Dura Mater Subarach. Space Filum Terminale may pierce one of the lower nerve-roots, giving rise to twitching in some of the. muscles of the lower extremity. The injection of stovaine or allied substances into the subarachnoid space to produce spinal analgesia is performed at the same point as lumbar puncture. The injection should not be made until the cerebro-spinal fluid escapes freely from the cannula when the trocar is with- drawn, for unless this occurs the cannula is not yet within the subarachnoid space. Mr. Barker has pointed out that the lowest part of the sub- arachnoid space when the body is supine is that situated in the mid-dorsal region, and that there- fore a fluid which is of greater specific gravity than that of the cerebro- spinal fluid (1007) will tend, if injected in the lumbar region, to gravi- tate to that part. By raising and lowering the patient's shoulders the rate of diffusion of the anaesthetic can be regu- lated to a considerable degree. Injections have also been made in the upper dorsal and cervi- cal regions through the interlaminar spaces, the spine being bent to extend these to their greatest width. The position of the cord is such that it is not readily reached in incised and punctured wounds. The only spots at which it is easy of access are the intervals between the atlas and occiput and the atlas and axis. Many cases have been recorded of fatal wound of the cord in these positions. Lower down in the column the medulla spinalis may be reached if the wound have a certain direction. Fig, 136. — Diagrammatic vertical section of the conus medullaris, filum terminale, and spinal membranes. XXVII] WOUNDS OF SPINAL CORD u:$ Thus a case is reported where a pointed body entered the canal between the 9th and 10th dorsal vertebrae, having been introduced from below upwards. Several examples of damage to the cord by sword or bayonet wounds have been put on record, but in most of these instances the wound was associated with some fracture of the protecting bone. The pia mater forms a strengthening sheath for the cord. On it the arteries ramify before Cauda Equina Conus Medullaris Dura Mater Arachnoid 4th Lumbar Fig. 137. — Transverse section of cauda equina and mem- branes at the level of the 4th lumbar vertebra. entering to supply its substance. The vertebral, intercostal, lumbar, ilio-lumbar, and lateral sacral arteries send twigs along the nerve-roots to the cord. Concussion of the cord.— After certain in- juries to the back a train of symptoms, usually of a severe and complicated character, has been described and assigned to a concussion or shaking of the spinal cord. In these injuries it is assumed that, as a result of a sudden shock transmitted to it, the cord undergoes certain molecular changes, which lead to a more or less severe disturbance of its function ; 044 THE SPINE AND SPINAL COED [Chap. and the condition has been compared to concus- sion of the brain, although it must be admitted that the symptoms often accredited to concussion of the cord have a character more complex than those seen in like lesions of the more complex organ. A great many surgeons are inclined to dispute the existence of this lesion, or rather decline to recognize the connexion between a certain train of symptoms and a simple molecular disturbance of the cord. i It is very probable that in many of the reputed instances of cord-concussion the symp- toms (if we except such as are assumed and such as depend upon changes in the brain) are due to a more distinct damage to the medulla spinalis, to haemorrhages, to pressure, and to other gross changes. Without entering into any discussion upon the subject, it may be sufficient to point out some of the anatomical objections that appear to oppose themselves to the common conception of concussion of the cord. The spinal cord is swung or suspended in its bony canal, and is separated from the walls of that canal on all sides by a con- siderable interval. It is, indeed, only Tield in position by the nerve trunks that pass out from it through the intervertebral foramina, and by its connexions with the theca. Above, it is con- nected with that part of the brain that lies upon the largest intracranial collection of cerebro- spinal fluid (p. 35), and it would appear that the most violent movements possible of the brain within the skull could be but very feebly communi- cated to the spinal cord. The cord, moreover, within its theca, is surrounded on all sides by a space occupied by cerebro-spinal fluid. It is diffi- cult to understand, therefore, how a structure so protected can be so violently disturbed by a shock received upon the body as to undergo a grave and progressive loss of function.* The cord is, indeed, somewhat in the position of a caterpillar sus- pended by a thread in a phial of water. It would probably be difficult permanently to disturb the XXVII] CONTUSION OF SPINAL CORD G45 internal economy of such an insect (even if it had a structure as elaborate as the cord) by other than violence that would be comparatively excessive. Contusion and crushing: of the cord.— As has already been observed, the gravity of frac- tures and dislocations of the spine depends upon the extent of the damage received by the cord. In these accidents it is very usual for some part of the injured vertebra to be projected into the spinal canal, so as to press upon or actually crush the delicate nerve centre that it contains. It is needless to observe that the cord is ex- tremely soft, and thus it happens that it may be entirely broken up by violence without the mem- branes being perceptibly damaged. Indeed, in fracture-dislocations it is unusual for the theca to be torn, and it is possible for the cord to be quite crushed at some one spot without the corre- sponding membranes being in any way lacerated. The amount of damage inflicted upon the cord will vary, of course, with the magnitude of the accident; but, other things being equal, it will be found to be more severely injured in fracture- dislocations of the cervical and dorsal segments than in like lesions in the lumbar spine. In the atlanto-axial region the amount of displacement that follows upon luxation of the two bones from one another is such that the cord is, as a rule, severely crushed, and death ensues instantaneously, as is seen in cases of death by hanging. In the cervical and upper dorsal segments of the column the vertebral bodies are small, the spine is mobile, the fractures met with in these parts are usually due to indirect violence, and are associated with much displacement. In the lower dorsal region, again, the greater rigidity of the spine renders any displacement, when it does occur, likely to be considerable. In the lumbar region, on the other hand, it must be noted that the cord only ex- tends to the lower border of the 1st vertebra. The bodies of the vertebrae, also, in this district, are very large and cancellous, and can undergo a 040 THE SPINE AND SPINAL COED LChap. severe amount of crushing without a correspond- ing degree of displacement being produced. The part, too, is well protected by the large inter- vertebral discs, and by the immense masses of muscle that surround the spine in the loins. Such portion of the spinal cord as extends into the lumbar region is protected also by the many cords of the cauda equina, which, by their looseness and comparative toughness, tend to minimize the effects of violence. The degree of displacement of bone required to produce pressure effects upon the cord is often greater than would be supposed. At post-mortem examinations portions of injured vertebrae have been found encroaching upon the spinal canal to a considerable extent in cases where no evidences of damage to the cord existed during life. Dr. J. W. Ogle reports the case of a man who, after an injury to the neck from a fall, presented no spinal symptoms until three days had elapsed. He ultimately became paralysed, and died thirty two days after the accident. The autopsy revealed a dislocation forwards of the 6th cervical vertebra, of such an extent that the body below projected at least J an inch into the spinal canal. The remarkable manner in which the cord will accommodate itself to a slowly progressing pres- sure is often well seen in the results of chronic bone disease in the column. The symptoms due to injury to the cord and to the nerves contained in the spinal canal will ob- viously depend upon the situation and extent of the lesion. The diagnosis of the situation of the lesion is complicated by the relation the nerves bear to the various vertebrae, and by the fact that the majority of the great trunks arise from the cord at a spot above the point at which they issue from the vertebral canal. The two highest nerves, the 1st and 2nd cervical, pursue an almost hcrizontal course in their passage from the cord to their points of exit from the canal. The re- maining nerves take a more and more oblique XXVII] CRUSHING OF SPINAL COKT) 647 direction, until at last the lowest nerve trunks run nearly vertically downwards as they pass to their respective intervertebral foramina. Points of exit of nerves from the vertebral canal. — The 1st cervical nerve leaves the canal above the 1st cervical vertebra. The remaining cervical trunks escape also above the vertebrae after which they are named, the 8th cervical nerve leaving the canal between the last cervical and the 1st dorsal vertebrae. The dorsal, lumbar, and sacral nerves have their points of exit below the vertebrae after which they are named. Thus, the 1st dorsal nerve will pass through the fora- men between the 1st and 2nd dorsal vertebrae, and so on. Points of Origin from the Cord The 1st cervical nerve arises from the cord opposite the interval between the atlas and occiput. The 2nd and 3rd cervical nerves arise from the cord opposite the axis. The 4th, 5th, Gth, 7th, and 8th cervical nerves arise from the cord opposite the 3rd, 4th, 5th, Gth, and 7th vertebrae respectively. The first four dorsal nerves arise from the cord opposite the discs helow the 7th cervical and the 1st, 2nd, and 3rd dorsal vertebrae respectively. The 5th and 6th dorsal nerves arise from the cord opposite the lower borders of the 4th and 5th vertebrae. The remaining six dorsal nerves arise from the cord opposite the bodies of the 6th, 7th, 8th, 9th, 10th, and 11th vertebrae. The first three lumbar nerves arise from the cord opposite the 12th dorsal vertebra. The 4th lumbar nerve arises from the cord opposite the disc between the 12th dorsal and 1st lumbar vertebrae. The last lumbar nerve, together with the sacral and coccygeal nerves, arises from the cord opposite the 1st lumbar vertebra. It will be seen, therefore, that in noting the symptoms due to crushing of the entire nerve contents of the vertebral canal at a certain spot, consideration must be taken, not only of the effects of damaging the medulla at that point, but also of the result of lacerating nerve-trunks that may issue there, although their origins are above the seat of lesion. The cord is also very often only G48 THE SPINE AND SPINAL CORD [Chap. damaged in part, or it may entirely escape, while one or more nerves are crushed by the fractured vertebrae or by fragments of bone separated by the lesion. In fractuie-dislocations the upper vertebral body, as already stated, usually glides forward, with the result that the anterior and antero- lateral parts of the cord are brought into violent contact with the projecting border of the ver- tebra below the seat of lesion. It is in these parts of the cord that the main motor tracts run, and thus it happens that motion is more often lost in the parts below the site of the injury than is sensation. If there be partial motor and sensory paralysis, the disturbance of the former function is likely to be in excess of that of the latter. In no case, indeed, does there appear to have been a loss of sensation without, at the same time, some disturbance in the powers of movement. If the grey matter of the cord be not severely damaged, reflex movements appertaining to that segment of the cord can usually be induced in the paralysed parts by proper stimulation. If those reflex movements be lost, it may be inferred that the grey matter is broken up, and that the entire spinal medulla has been crushed at the seat of lesion.^ The higher up the fracture in the column the greater is the tendency for the function of respira- tion to be interfered with. If the lesion be at the upper end of the dorsal spine, then not only will all the abdominal muscles be paralysed, but also all the intercostals. A fracture associated with injury to the cord, when above the 4th cervical vertebra, is, as a rule, instantaneously fatal. The phrenic nerve comes ^ off mainly from the 4th cervical nerve, receiving contributions also from the 3rd and 5th. The 4th nerve issues just above the 4th cervical vertebra. If the cord be damaged immediately below this spot, the patient can breathe only by means of the diaphragm ; and if the lesion be so high as to destroy the XXV11] INJURY TO SPINAL CORD 649 main contribution to the phrenic, respiration of any kind becomes impossible. Certain disturbances of micturition are fre- quent in cases of injury to the cord. The re- flex centre for this act is lodged in the lumbar enlargement. The irritation of the vesical walls, produced by the increasing distension of the bladder, provides the needful sensory impulse. This impulse is reflected to the nerves controlling the bladder muscles, and especially to the detrusor urinse, and by their contraction the organ is emptied (p. 470). The action, however, can be to some extent inhibited by influences passing down from the brain to the lumbar centre, and the tendency to a frequent discharge of urine is re- sisted by contraction of the sphincter. When, therefore, any part of the cord between the lumbar centre and the brain is damaged, inhi- bition can have no effect. Immediately after the accident the temporary suspension of reflex actions from shock produces some retention of urine, and after that the bladder empties itself at frequent intervals, the patient being unconscious of the act and unable to influence it. If the centre itself be damaged in the lumbar cord, the patient, after a little retention, will suffer from absolute incontinence ; and a like result will follow if the nerve connexions between the cord and bladder below the spinal centre have been destroyed. The principal nerves connecting the medulla spinalis with the bladder are the 3rd and 4th sacral. The act of defalcation also is apt to be dis- turbed in a like manner. Here there is, as in the previous case, a reflex centre in the lumbar en- largement, with motor and sensory nerves connect- ing it below with the rectum and its muscles ; and also between this centre and the brain are tracts, but little known, along which inhibitory actions can extend. When the centre itself is damaged, or the con- nexion severed that unites it with the viscus, the v* 650 THE SPINE AND SPINAL CORD [Chap. patient will suffer from incontinence of faeces and will be unable in any way to control the act. When the cord is damaged at any spot between the centre and the brain, then the act of defsecation will be performed at regular intervals, without either the patient being conscious of the act or being capable of inhibiting it. In some injuries to the cervical cord tho patient has suffered from severe vomiting for some time after the accident, or has exhibited a remark- able alteration in the action of his heart. Mr. Erichsen, for example, reports the case of a man who, after a severe blow upon the cervical spine, continued to vomit daily for several months. In the other category, instances have been recorded where the pulse has sunk as low as 48, or even 36 or 20, after lesions to the column in the neck. These changes are supposed to be due to dis- turbance of the vagus, and it is further suggested that the morbid influence is conveyed to the vagus by the spinal accessory nerve with which it is so freely associated. It should be remembered that the spinal acces- sory trunk has origin from the cord as low down as the 6th or 7th cervical nerves. Some details concerning the position of centres in the spinal cord, connected with areas of skin, groups of muscles, and viscera, have been given already when dealing with the nerve supplies of the extremities and abdomen (see pp. 346 and 625). Spina bifida. — This term refers to certain congenital malformations of the vertebral canal associated with the protrusion of some of its con- tents in the form of a fluid tumour. The mal- formation usually consists in an absence of the neural arches and spines of certain of the verte- brae, and the tumour therefore projects pos- teriorly. Spina bifida is most common in the lumbo-sacral region, the neural arches of the last lumbar and of all the sacral vertebrae being ab- sent. In development the neural arches close first in the dorsal and last in the lumbo-sacral region. XX VIII MENINGO-MYELOCELE 651 Next in frequency it is found limited to the sacral region. It is rare elsewhere. (1) The membranes may protrude alone {spinal meningo- cele). (2) The membranes may protrude together with the spinal cord and its nerves (meningo- myelocele). (3) The membranes may protrude with the cord, the central canal of which is dilated, so as to form a sac-like cavity (syringo- myocele). (See Figs. 135 and 136.) The meningo= myelocele is the most common form. The first-named variety is rare, the last- named very rare. When the cord occupies the sac it usually adheres to its posterior wall, the nerves running transversely across the sac to reach the intervertebral foramina. When compressed, the cerebro-spinal fluid is forced into the subarach- noid spaces at the base of the brain, which is forced upwards against the anterior fontanelle, where its impact may be felt. The tumour be- comes enlarged and tense when the child cries. The distension of the cerebral and spinal veins forces the fluid in the direction of least resistance. As might be expected, spina bifida is very com- monly associated with some evidence of injury to the nerves arising from the lower part of the spinal cord. The defect occurs at an extremely early stage of development, and hence part of the cord or of the nerves in the region of the tumour may be absent or defectively developed. In some cases the nerve affection takes the form of club-foot of a severe grade. In other instances there is more or less complete paralysis of the lower limbs, bladder, and rectum. Operations upon the cord. —Sir Victor Horsley and others have cut down upon the spine and removed a tumour from the spinal cord with perfect success, and with relief to the symp- toms from which the patient was suffering. The spinal canal has also been exposed in certain cases where callus in an old fracture of the spine was pressing upon the cord, or where a small osseous growth was encroaching on the canal. INDEX Abces en bissac, 592 • en bouton de chemise. 592 Abdomen, 332 ■ • abscess of, 342 • blood-vessels of, 335, 343, 442 ■ blows on, 337 congenital deformities of. 349 connective tissue of, 342 ■ fascia of, 336 ■ lymphatics of, 344 muscles of, 341 ■ nerves of, 344 ■ parietes of, 332, 335, 366 — — • skin of, 335 surface anatomy of, 332 ■ tension or pressure with- in. 359 ■ • wounds of, 342 Abdominal aorta, 335 " ■ belt," 336 - — ■ connective tissue and ab- scesses, 342 - — ■ rings, 351, 354 ■ viscera, 371 • > nerve supply of, 440 ■ • support of, 380 ■ ■ surface markings of, 378 Abscess, alveolar, 142 ■ . axillary, 244 - — - cerebral, 11 ■ ■ • trephining for, 9 • ■ cervical, 174 • gluteal, 505 • hepatic, 418 • ■ iliac, 342, 367, 368 > in antrum, 114 ■ in hip-joint, 518 ■ in scalp. 6 • ■ in temporal fossa, 8 ■ intercostal, 209 intracranial, 10 ! ■ ischio-rectal, 458 Abscess, lumbar, 367, 370 — — mediastinal, 221 — - of abdominal parietes, 342 — of Bartholin's gland, 489 of mastoid cells, 91 ■ ■ orbital, 54 ■ palmar, 311 ■ parotid, 129 ■ pelvic, 518 • peri nephritic, 430 « plantar, 592 « popliteal. 554 ■ postpharyngeal, 160 ■ prostatic, 475 ■ • psoas, 368, 513 — renal, 431 retropharyngeal, 368 subfascial, 353 temporo-sphenoidal, 10 thecal, 314 • typhlitic, 400, 401 Accessory glands of tongue, 151 • sinuses, 110 Acetabulum, 445, 518 ■ fractures of, 445 " Aching legs," 580 Acne hypertrophica, 98 Acromegaly, 39 Acromio-clavicular joint, 225, 237 ■ dislocations of, 238 ■ ■ movements of, 237 Acromio-thoracic artery, 226, 228 Acromion process, 224 ■ fracture of, 240 Adductor longus muscle, 511, 514 — magnus tubercle, 549 Adenoids, 159 Agatz's plate, 617 Air in veins, 195, 247 Air-passages, foreign bodies in, 187 653 654 SURGICAL APPLIED ANATOMY Air-sac in neck, 202 " Alderman's nerve," 86 Alimentary canal, rate of progress of contents of, 403 Alveolar abscesses of teeth, 142 Ampulla of Vater, 420, 425. 426 Amputation (sec various bones and joints) Anal canal, 491 mucous membrane of, 497, 498 ■ ■ triangle, 455 ■ valves, 497 Anastomosis, abdominal, 442 — intestinal, 397, 412 Anastomotica magna, 551 Aneurysm, aortic, 195. 442 — — arterio-venous, 56 ■ gluteal, 507 ■ in axillary artery, 247 — in neck, 195 . of femoral artery, 515 of posterior tibial artery, 579 ■ popliteal, 556 ■ traumatic, 56 Ankle, 587 — • bony points of, 587 • fascia of, 591 skin of, 590 — sprains of, 593 ■ subcutaneous tissue of. 590 ■ surface anatomy of, 587 tendons of, 588, 595 Ankle-joint. 588, 597 amputation at, 617 ■ disease of, 598 ■ dislocations of, 599 ■ fractures about, 599 — — • nerve supply of, 599 — vessels of, 589 Annular ligament of ankle, 592 • ■ of wrist, 311 Ano, fistula in, 458 Anosmia, 109 Anterior crural nerve, 516, 621 ■ nares, 100 superior spine, 333 Anticlinal spine, 215 Antrum, mastoid, 91 • of Highmore, 113 Anus, 497 ■ imperforate. 498 nerves of. 500 ■ ulcers of, 497 Aorta, abdominal, 335, 442 — - thoracic, 195 Apical point of thorax, 218 Aponeurosis (see Fascia) Appendicitis, 401 Appendicostomy, 411 Appendix, 400 ■ length of, 400 — lymphatics of, 401 mesentery of, 401 • position of, 400 Aqueduct of Fallopius, 90 Aqueous humour, 71 Arachnoid, 34. 640 Arcuate tendon of levator ani, 452 Arcus senilis, 61 Arm, 264 ■ amputation of. 270 ■ epiphyses of, 331 — — fascia of, 265 lymphatics of, 278 muscles of, 325 ■ nerves of, 265, 324 ■ skin of, 265 ■ surface anatomy of, 264 Arnold's nerve, 85 Arteries (see Axillary, etc., and Blood-vessels) Arterio-venous aneurysms, 56 Arthrectomy, 575 Aryteno-epiglottic folds, 159, 180 Ascaris lumbricoides, 392 Ascending colon, 405 Astragalo-scaphoid joint. 588 Astragalus, dislocation of, 606 ■ fracture of, 614 Atlanto-axial region of spine, 632 Atlas, 159 Attic of tympanum, 88, 91 Auditory meatus, external, 83 Auricle (see Ear) Auricles, supernumerary, 202 Auricular nerve, 169 Avulsion of fingers, 323 Axilla, 227, 242 — fasciae of, 243 lymphatic glands of, 245 relations of, 243 Axillary artery, 227 ■ aneurysm of, 247 • ■ ligature of, 248 • ■ relations of, 243 • glands, 198, 212, 227 — removal of, 246 — nerves, 249 ■ region, abscess of, 244 INDEX 655 Axillary vessels, 246 . . ■ wounds of, 247 Axis, 159 Azygos veins, 222 Barbadoes leg. 518 Bartholin's duct, 144 . gland, 488 • abscess of, 489 Basal ganglia, 44 Base of condyles of humerus, fracture at, 285 of skull, fractures of, 27 Basilic vein, 264 Bell's muscle, 471 Biceps tendon in arm, 253 ■ — in ham, 555 Bicipital groove, 226 Bile-duct, relations of, 415 - rupture of. 421 Bladder, 465 ■ cystoscopic examination of, 469, 471 development of, 340 ■ distension of, 466 ■ double, 471 ■ empty, 465 ■ extroversion of, 350 fasciculated, 470 female, 471 foreign bodies in, 472 ■ in hernise, 467 - — ■ male, 465 ■ mucous membrane of, 469 ■ muscles of, 471 muscular coat of, 470 ■ nerves of. 470, 500 ■ of child, 472 ■ puncture of, above pubes, 466 ■ — — per rectum, 468 relations of, to peri- toneum, 465, 466, 467 rupture of, 468 sacculated, 470 stone in, 462 Blood tumours of scalp, 7 on pinna, 85 Blood-vessels of abdomen, 335, 343, 442 ■ ■ of ankle, 589 of auditory meatus, 83 of axilla. 246 of brain, 47 of breast, 213 of buttocks. 504, 507 of elbow, 276 • of eye, 56 of eyeball, 64 Blood-vessels of eyelids, 77 of foot, 590, 596 of forearm, 292 - of gall-bladder, 419 of hand, 315 of heel, 617 — — of knee, 555 of leg, 579 of nasal cavities, 108 of neck, 194 of orbit, 56 of palate, 156, 157 of perineum, 456 of pinna, 85 of rectum, 495 of retina, 65, 66 — — of scalp, 13 ' of Scarpa's triangle, 515 of spermatic cord, 487 of spinal cord, 643 • of tongue, 148 of tonsil, 164 of tympanum, 96 Bones, nerve supply of, 331 Bony vault of cranium, 17 Brachial aponeurosis. 266 • artery, 264, 267, 278 abnormalities of, 258 fascia, 266 plexus, 170, 248 — — paralysis of, 328 relations of, 243 Brachialis anticus, 266 Brain, 31, 46 basal ganglia of, 44 « blood-vessels of, 47 cisternae of, 35 ■ ■ concussion of, 47 cortex of. 45 fissures of, 39. 42 inferior temporal con- volution of, 44 injuries to, 47 membranes of. 31 motor areas of, 40, 45 surface relations of. 39 Branchial fistuke, 200 Brasdor's operation, 194 Breast (see Mamma) Bregma, 17 Broca's convolution, 43 Bronchi, foreign bodies in, 187, 218 Bronchial lymphatic glands, 192 Bronchocele, 188 Brunner's glands, 395 Bryant's method of dividing muscles of palate, 157 666 SURGICAL APPLIED ANATOMY Buccal cavity, 144 lymphatics of, 198 nerve, 123 Bulla ethmoidalis, 106 Bunions, 594 Bursas about elbow- joint. 279 about foot, 594 about ham, 557 about hyoid, 179 — — about knee, 553, 557 ■ about Scarpa's triangle, 514 about shoulder- joint, 252 - — . . relations of, 250 — — over great trochanter, 506 over ischial tuberosity, 507 patellar, 553 subacromial, 252 subpsoal, 514 Buttocks, 502 abscess of, 505 ■ fascia of, 505 ■ ■ fold of, 503 ■ nerves of, 504, 507 skin of, 504 nerve supply of, 510 — — subcutaneous fascia of, 504 surface anatomy of, 502 vessels of, 504, 507 Caecum, 398 foreign bodies in, 400 ■ hernia of, 399 in intestinal obstruction, 400 lymphatics of, 401 movements of, 400 opening of, 411 ■ position of, 398 Caesarian section, 448 Calcaneo-cuboid joint, 588 Calcaneo-scaphoid ligament, 610. 611 Calcar femorale, 527 relations of, 529 Calyces of kidney. 438 Canal of Nuck, 359 ■ of Schlemm, 72, 73 Cancer en cuirasse, 212 ■ of breast, 211 ■ of pylorus, 427 of rectum. 496 - of stomach, 223, 388 of tongue, 151 Capsule of lens, 70. 72 of shoulder-joint, 252 relations of, 250 Capsule of Tenon, 52 Cardiac orifice, 381, 382 Caries of lumbar vertebrae. 370 of sternum, 206 of teeth, 140 ** sioofL " 94 Carotid artery, 129, 165, 167, 195 ■ aneurysm of, 195 external, 129 ligature of, 194 sheath of, 174 tubercle. 165, 195 Carpo-metacarpal joint, 318 Carpus, fracture of, 321 Castration, 476, 483, 487 Cataract, 70 Catheterism of Eustachian tube, 96 of urethra, 477 Cauda equina membranes, sections of, 642, 643 Cavernous sinus, 33 Cephalhaematomata, 7 Cephalic vein, 273, 276 Cerebellum, abscess of, 11 lesions of, 49 point for trephining, 11 - tumours in. 49 • veins of, 49 Cerebral abscess, trephining for, 9 circulation, 36, 47 • localization, 45 • tumour, trephining for, Cerebro-spinal fluid, 37, 638, 640. 641 in cranial spaces, 35 Cervical artery, 169 resrion of spine, 630 sac, 202 sinus, 200 ■ sympathetic, paralysis of, 58 (see also Neck) Cervico-dorsal region of spine, 632 Cervix uteri. 490 Check ligaments, 53 Cheloid, sternum a frequent seat of, 205 Chest (see Thorax) Cholecystectomy, 423 Cholecystenterostomy, 423 Cholecystotomy, 422 Chopart's operation, 619 Chorda tympani nerve, 96 INDEX 657 Choroid, 62 Ciliary muscle, 72 zone, 65 Circumcision, 480 Circumflex artery, external, rupture of, 543 . internal, wound of, 543 , posterior, 229, 251 . nerve, 229, 251 Cirsoid aneurysm. 13 Cisternse of brain, 35 Clavicle, 224. 229 absence of, 234 ■ dislocations of, 236, 238 ■ excision of, 230 ■ fracture of, 231 movements of, 235 - ossification of, 234 ■ relations of, 228, 233 resection of, 230 Cleft palate, 153 " Clergyman's sore throat," 182 Club-foot, 608 Coccygeus, 450 Coccygodynia, 450 Coccyx, 450 Cochin leg, 518 Cceliac axis, 335, 442 Colectomy, 411 Colles' fascia, 459 fracture, 318 Colombia iridis, 64 Colon, 404 ■ antiperistalsis in, 493 — — ascending, 405 congenital malforma- tions of, 412 descending, 405 ! relations of, 409 ■ iliac, 405 ■ operations on, 411 ■ pelvic, 407 ■ stricture of, 405 ■ transverse, 405 ■ relation of, to liver, 417 Colotomy. iliac, 411 inguinal, 411 lumbar, 405 Commissures of prostate, 473 Concussion of brain, 47 of spinal cord, 643 Condyles of humerus, frac- ture at base of, 285 Congenital absence of cla- vicle, 234 of patella, 569 Congenital absence of rectum, 408 deficiency of rectum, 408 deformities of abdomen, 349 ■ dermoid cysts, 146 dislocation of hip, 531 - — - exomphalos, 349 • fistulse, 82, 200 ■ hernia, 339. 351, 358 — — malformations of anus, 498 of colon, 412 of rectum, 498 thyroid cysts, 146 Conjunctiva, 77 Contusion of spinal cord, 645 Conus medullaris membrane, section of, 642 Convolution, Broca's, 43 inferior temporal, 44 Coraco-acromial ligament, 226 Coraco-brachialis muscle, 227 Coracoid process, 226 ■ ■ fracture of, 241 Cornea, 59 ■ dimensions of, 59 nerves of, 61 Coronal structure. 18 Coronary artery, 385 Coronoid process, fracture of, 288 Corpus striatum, 44 Cortex, motor centres of, 40, 45 Costo-rectal point, 380 Costo-vertebral ligament, 436 " Coup de fouet," 579 Cowper's gland, 489 Coxa vara, 530 Cranial bones, blood supply of, 5 necrosis of, 5 - — ■ nerves, 57 spaces containing cere- brospinal fluid, 35 Craniectomy, 30 Cranio-cleido-dysostosis, 234 Cranio-tabes, 18 Cranium, bony vault of, 17 ■ {see also Skull) Cremaster muscle, 487 Cremasteric artery, 487 Cribriform plate, 104 Cricoid cartilage, 180 " Cross-legged progression," 525 Crucial ligaments of knee- joint, 558 Crural canal, 360 658 SURGICAL APPLIED ANATOMY Crural canal, hernia into, 362 • relations of, 362 nerve, anterior, 516, 621 paralysis of, 621 sheath, 366 " Crutch paralysis," 268 Cuboid bone, dislocation of, 614 Cuneiform bone, inner, 587 dislocation of, 614 fracture of. 614 Cut throat, 177 Cystocele. vaginal, 489 Cystoscopic examination of bladder, 469. 471 Cysts in floor of mouth, 146 ■ of scalp, 2 Dacryops, 79 Dartos tissue, 336 Deep sensibility, 124, 330 Defsecation in spinal injuries, 649 Deltoid, 225 . muscle, 249, 264 region, 225, 249 ■ tubercle, 224 Dermoid cysts, congenital, 146 Descending colon, 405 Diaphragm, 416 Diaphragmatic hernia, 365 Diastolic empty bladder. 466 Diploic veins, 14 Dislocation (see various bones and joints) Divarication of recti, 338 Dorsalis pedis artery, 596 scapulae artery, 229 Dorso-lumbar region of spine, 632 Dorsum ilii, dislocation upon, 532, 535 " Double-chin," 170 Douche, nasal, 103 " Drop-wrist," 329 Duodeno-jejunalis fossa, 394, 395 Duodenum, 394 occlusion of, 395 suspensory muscle of, 394 Dupuytren's contraction. 309 fracture. 602 Dura mater, 31, 639 Ear, 82 . bleeding from, in frac- ture of base of akull, 29 blood supply of, 85 29 Ear, blood tumours on, 85 ■ coughing, 86 external, 83 haematomata of, 85 labyrinth of, 97 ■ lymphatics of, 198 - — - nerve supply of, 85 ■ ossicles of, 88 sneezing, 86 watery discharge from, — — yawning, 86 Ecchymosis, 631 Ectopia vesicas, 350 Elbow, 272 ■ dislocations of. 282 ■ fold of, 272 fractures about, 285 lymphatic glands of, 278 . nerves of, 277, 290 resection of, 289 ■ skin of, 275 ■ surface anatomy of, 272 ■ veins of, 276 Elbow-joint, 279 « bursae about, 279 disease of, 280 ■ ligaments of, 279 sprains of, 280, 285 Elephantiasis Arabum, 517 ■ of scrotum, 483 Eminentia articularis, 126 Emissary veins of skull, 13 Emphysema. 216 Encephalocele. 19, 100 Encysted hernia, 358 hydrocele of cord, 357 Enterectomy, 397 Enterocele, vaginal, 489 Enterotomy, 397 Epicondyle, fracture of, 286 Epicritic sensibility, 124, 330 Epididymis, 485 nerve supply of, 486 Epiphora, 80 Epiphyseal line, relations of, 250 Epiphysis in knock-knee, 567 of acromion, separation of. 240 of clavicle, separation of. 234 ■ of coracoid, separation of. 241 • ■ of femur, separation of, 525, 530, 573 of humerus, separation of. 261. 287 ■ of olecranon, separation of, 288 INDEX 6o9 Epiphysis of pelvis, separa- tion of, 448 of radius, separation of, 289, 321 of tibia, separation of, 574, 584 • of upper limb, 331 Epipteric bone, 21 Epispadias, 482 Epistaxis, 108 Erb's palsy, 249 Erector spinae muscle, 629 Erysipelas of scalp, 14 Estlander's operation, 209 Ethmoidal cells, 105 Eustachian catheter, 96 ■ tube, 94 Eversion, movements of, 605 Excision (see special parts) Exomphalos, congenital, 349 Extensor brevis digitorum tendon, 589 communis digitorum muscle, 576 longus digitorum tendon. 589 hallucis muscle, 576, 577 tendon. 588 External auditory meatus. 83 blood supply of, 85 ■ nerve supply of, 85 carotid artery. 129 ■ pterygoid muscle, 138 Extroversion of bladder, 350, 459 Eyeball, 50 blood supply of, 64 dangerous area of, 68 nerve supply of, 66 Eyelashes, 77 Eyelids, 75 arteries of, 77 nerves of, 77 subcutaneous tissue of, 76 ■ sycosis of, 77 Face, 116 > blood supply of, 117 cellular tissue of, 116 ■ development of, 119 • injuries to, 117 ■ lymphatics of, 198 ■ nerves of, 119 — ■ skin of, 116 vessels of, 117 Facial artery, 118, 167 Facial nerve, 90, 130 palsy, 80 Fallopian tube, 490 Fallopius, aqueduct of, 90 Fascia, abdominal, 336 . anal, 452 axillary, 243, 244 . bicipital. 272, 277 ■ brachial, 266 ■. cervical, 171 • clavi-pectoral. 244 gluteal, 505 - — - iliac, 366 ■ lata, 506, 513, 541 lumborum, 369 • obturator, 452 of ankle, 591 ■ of arm, 266 ■ of buttocks, 505 , of Oolles, 459 - — - of deltoid region, 250 _ of foot, 591 of hand, 309 of leg, 578 • of scalp, 1. 6 ■ of Scarpa's triangle, 513 ■ of thigh, 541 palmar, 309 - parotid. 127 • pectoral, 244 pelvic, 451 ■ perineal, 459 ■ plantar, 589 popliteal, 554 ■ postnephric, 431 ■ prenephric, 431 > Scarpa's, 362 ■ Sibson's, 175 ■ temporal, 8 ■ transversalis, 366 ■ visceral, 452 Fasciculated bladder, 470 " Fatty hernia," 339 ■ tissue in scalp, 2 Femoral artery, 507 diverticula, 366 epiphysis, 573 ■ hernia, 360 point, 352 vessels. 512, 515, 543 aneurysm of, 515 ■ phlebitis of, 515 Femoro-sacral arch, 445 Femur, dislocations of, 570 epiphysis of, 525, 530 ■ fractures of, 527, 544, . symptoms of, 529 • lower end of, 571 531, 571 660 SURGICAL APPLIED ANATOMY Femur, neck of, 527 upper end of, 527 Fenestra ovalis. 89 rotunda, 89 Fergusson's method of divid- ing muscles of palate, 157 Fibrous polyp of nose, 108 sheaths of hand, 311 Fibula. 582 and tibia, fractures of, 582, 599 fractures of, 584, 599 Fifth nerve, 15, 58, 86, 99, 119, 123 ■ paralysis of, 58 Filaria sanguinis hominis, 518 Finger, little, " congenital contraction " of, 312 " snap," 312 • " mallet," 318 Fingers, avulsion of, 323 nerve supply of, 325 Fissure of Rolando, 41 of Sylvius, 41 parieto-occipital, 44 Fissures of brain, 39, 42 of Santorini, 84 ■ parietal, 21 Fistula at navel, 340 between gall-bladder and intestine, 423 branchial, 200 congenital, 82, 200 gastric, 384 ■ in ano, 458 - lachrymal. 81 recto-vaginal, 489 salivary, 133 umbilical, 340 vesico-vaginal, 489 Flat-foot, 591, 610 Flexor longus digitorum ten- don, 589 Fontana, spaces of, 72 Fontanelle, sagittal, 21 temporary occipital, 20 Fontanelles, 17 Foot, 587, 603 abscess of, 592 amputations of, 617 arches of, 603 blood-vessels of, 589, 596 bony points of, 587 bursae about, 594 club, 608 dislocations of, 606, 607 fascia of, 591 flat-, 591, 610 — — fractures of, 613 Foot, imprints of, 612, 613 integuments of, 590 joints of. 605 lymphatics of, 697 movements of, 605 muscles of, 605 - nerves of, 590 - — - perforating ulcer of, 591 • surface anatomy of, 587 - synovial cavities of, 617 Foramen caecum, 152 infra-orbital, 120 of Key, 37 of Magendie, 36 of Monro, 36 of Retzius, 37 of Winslow, 376 ovale, surface markings of. 123 ■ supra-orbital, 120 Forearm, 291 amputation of, 297 bones of, 293 fractures of, 295 luxations of, 282 surface anatomy of, 291 vessels of, 292 Foreign bodies in air-passages, 187 in bladder, 472 in bronchi, 218 — — in caecum, 400 in oesophagus, 192 in orbit, 54 in pharynx, 158 in rectum, 493 in stomach. 385 in trachea, 218 in vitreous humour, 73 Fossa duodeno-jejunalis, 394, 395 - ileo-caecal, 403 intersigmoid, 407 ischio-rectal, 457 nasal, 103, 104 ■ of Rosenmuller. 95 • retrocaecal, 403 subclavicular, 226 Fourth nerve, paralysis of, 57 " Fracture helicoide," 583 Fractures (see the several bones) Fraenum linguae, 147 Frontal sinus. 110 infundibulum of, 105, 112 Funicular process, 357 hernia into, 358 INDEX 661 Galen, veins of, 37 Gall-bladder, 415, 419 arteries of, 419 excision of, 423 ~ fundus of, 415 incision into, 422 nerve supply of, 420 operations on, 422 relations of, 415 rupture of, 421 tumour in. 422 veins of. 419 Gall-stones, 419, 421 Gangrene of leg, 579 of small intestine, 442 Gasserian ganglion, excision of, 125 position of, 12 Gastrectomy, 388 Gastric fistula, 384 ulcers, 384 Gastrocnemius muscle, 577 rupture of, 579 Gastro-hepatic omentum, 420 Gastrojejunostomy, 389 Gastroplication, 389 Gastrostomy. 386 Gastrotomy, 386 Generative organs, female, 488 . ■ male, 480 Genito-crural nerve, 437 Genu valgum, 565 ■ ■ epiphysis in, 567 Giantism, 39 Gimbernat's ligament, 362 Gladiolus, 205 Glans penis, 481 . . ■ mucous membrane of, 481 Glaucoma, 61, 62. 74 Glaucomatous cup, 75 Glenard's disease, 378 Globe, 59 (see also Eyeball) Gluteal abscess, 505 aneurysms, 507 artery, 504, 507 . ■ bursae, 506 ■ ■ fascia. 506 ■ • fold, 503 muscle, 506 ■ region, 502 Gluteus maximus, 450. 506 rupture of, 506 Goitre, 188 Granular lids, 79 Green-stick fracture. 233 Groin, region of, 511 Gubernaculum, relations of, 356 Gullet (see (Esophagus) Gummatous periostitis of sternum, 206 Gums, 146 lymphatics of, 198 Gustatory nerve, 146 Haematoniata of scalp, 7 on pinna, 85 Haematuria, 430, 631 Haemoptysis, 216 Haemorrhage from choroid, 62 from lung, 216 from tongue, 148 ■ from tonsil, 164 from uterus, 489 from vagina, 489 into vitreous, 66 meningeal, 32 Haemorrhoidal vessels and nerves, 459, 463, 495 Haemothorax, 216 Hallux rigidus, 616 ■ valgus, 616 Ham (see Popliteal) Hammer toe, 616 Hamstring muscles, 550, 554 Hand, 300 abscess of, 311 amputations of, 323 - blood-vessels of, 315 bones of, 316 creases of skin of, 303 ■ dislocations of, 322 fasciae of, 309 fibrous sheaths of, 311 ■ joints of, 316 lymphatics of, 315 - — nails of, 308 nerve supply of, 307 skin of, 303, 306 subcutaneous tissue of, 307 surface anatomy of, 302 synovial cavities of, 322 sacs of. 312 ■ sheaths of, 312 Hanging, mode of death from, 645 Hard palate, 155 ■ blood supply of, 156 Hare-lip, 153 Heart, 218 exposure of, 220 relations of, 219 wounds of, 220 Heel, blood supply of. 617 integuments of, 617 ■ nerve supply of, 618 662 SURGICAL APPLIED ANATOMY Helicoidal fractures of Le- riche, 545, 583 Hepatic abscess, 418 Hernia, 351 csecal, 399 congenital, 339, 351, 358 diaphragmatic, 365 direct, 354, 355 encysted, 358 ■ fatty, 339 femoral, 360 ■ • indirect, 355 infantile, 358 inguinal, 351 ■ internal, 354 ■ into crural canal, 362 into funicular process, 358 ■ ischio-rectal, 364 -— lumbar, 364 ■ . mesenteric, 396 ■ mesocolic, 396 . mesogastric, 396 oblique, 354, 355 obturator, 363 . of lung, 216 • omental, 372 perineal, 364 ■ pudendal, 364, 488 rare forms of, 364 - retroperitoneal. 396 sciatic, 364 strangulated, 407 • • umbilical, 339, 364 Herniae, bladder in, 467 Hernial sacs, 351 Herniotomy, 360, 363 Herpes zoster, 348 Hesselbach's triangle, 354 Hiatus semilunaris, 105 Highmore, antrum of, 113 Hilum of kidney, 428, 436 Hip, dislocations of, 531, ■ ; - — — anatomy of, 535 ..__ modes of reducing, 538 region of, 502 Hip-joint, 518 • abscess in, 518 amputation at, 538 ■ . disease, 520, 525 ■ . ■ chronic, 521 • fractures about, 527 movements of, 520 nerve supply of, 525 relations of, 519 Holden's line. 511 " Hottentot Venus," 505 Human tails, 450 Humerus, 225 • dislocations of, 255, 257, 258 259 fractures of, 260, 268, 285 ■ — — non-union after, 269 Hunter's canal, 543 Hyaloid membrane, 73 Hydatid cysts of lung, 217 Hydrencephalocele, 19 Hydrocele, 484 encysted, of cord, 357 of neck, 202 Hydrocephalus, 17, 18, 37 Hydronephrosis, 433 Hyo-glossus muscle, 167 Hyoid bone, 166, 179 . accessory glands about, 189 — r bursse about, 179 ■ fracture of, 179 ■ ■ wounds of, 177 Hypertrophy of prostate, 475 of pylorus, 387 of tonsil, 161 Hypodermic injection, 510 Hypogastric line. 379 Hypoglossal nerve, 130, 150 Hypopyon, 73 Hypospadias, 482 Hypothenar eminence, 302 Hysterical hip, 526 . knee, 526 Tleo-csecal fossa, 403 intussusception, 402 ■ orifice, 402, 403 region, 398 - sphincter, 400 • — - valve, 403 Ileo-colic angle, 402 intussusception, 402 Ileum (see Intestine, small) Iliac abscess, 342, 367 ■ ■ colon, 405 ■ ■ multiple diverticula , of mucous coat of, I- 409 ■ colotomy, 411 - — - fascia, 366 Ilio-psoas muscle, 514 Ilio-tibial band, 550 Indirect hernia, 355 Infantile hernia, 358 Inferior cava] point, 218 dental nerve, 122 maxilla, 135 deformities of, 140 dislocations of, 137 excision of, 139 INDEX Inferior maxilla, fracture of, 135 nerves of, 140 subluxation of, 138 mesenteric artery, 335 plexus, 440 — — ■ temporal convolution, 44 thyroid artery, 191 ■ vena cava, 220 Infra-orbital artery, 121 foramen, 120 . nerve, 120 Infundibulo-pelvic ligament, 491 Infundibulum, 112 ■ of frontal sinus, 105. 112 Inguinal canal, 359 colotomy, 411 ■ diverticula. 366 glands, 512, 516 ■ hernia, 351 Innominate artery, 195 bone, 448 Intercarpal joint, 317 Intercostal abscess, 209 artery, 208, 209 • muscles, 209, 629 spaces, 208 Intercosto-humeral nerve, 213 Internal cutaneous nerve, 277 hernia, 354 . mammary artery, 210 Interparietal bone. 21 Interscapulo-thoracic amputa- tion, 242 Intersigmoid fossa, 407 Interstitial keratitis, 60 Intervertebral discs, 628 Intestinal anastomosis. 397, 412 Intestine, large, 404 (see also Colon) ■ excision of, 412 small, 389 diverticula of, 392 ■ gangrene of, 442 in pelvis, 390 . injury to, 391 length of, 389 — operations on, 397 ■ ■ • position of, 390 ■ • resection of, 397 ■ strangulation of, 340, 393 Intracranial abscess, 10 Intrathoracic disease, Ront- gen rays in, 221 Intussusception, 402 Inversion, movements of, 605 Iridectomy, 64, 74 Iris, 58, 63 Iritis, 63 Ischial spine as guide to ureter, 440 Ischio-rectal abscess. 458 . fossa, 457 hernia, 364 Ischio-sacral arch, 445 Islets of Langerhans, 427 Isthmus of thyroid, 186, 189 Jaws (see Inferior and Superior maxilla) Jejunum, 389 Joints, surgical classification of, 251 Jugular vein, 90, 91, 168, 198 Keloid (see Cheloid) Keratitis, interstitial, 60 Key, foramen of. 37 Kidney, 427 abnormalities of, 433 ■ abscess of, 430, 431 ■ development of, 434 fusion of, 434 hilum of, 428. 436 horse-shoe, 434 movable, 431 nerve supply of, 432, 501 ■ operations on, 434 ■ pelvis of, 428. 436 position of, 428 • relations of, 427 rupture of, 430 - " sacral," 434 ■ support of, 432 ■ vessels of, 335 Knee, 548 ■ blood sunply of, 552 — - bursse about, 553. 557 - dislocations of, 570 fractures about, 571 front of, 551 • blood supply of, 552 skin of, 551 subcutaneous fat over. 552 ■ lymph glands of, 553, 557 • pain in, in hip-joint disease, 525 surface anatomy of, 548 ■ (see also Popliteal) Knee-cap (see Patella) Knee-joint, 558 ■ amputation through, 575 ■ crucial ligaments of, 558 derangement of, 563 disease. 562 664 SURGICAL APPLIED ANATOMY Knee-joint, excision of, 573 lateral ligaments of, 558 — — synovial membrane of, 560 Knock-knee, 565 ■ epiphysis in. 567 Kraske's operation, 496 Kyphosis, 204, 628 Labia majora, 488 Labyrinth of ear, 97 osseous, 97 Lachrymal abscess, 80 ■ apparatus, 79 ■ fistula, 81 gland, 79 sac, 79 Lacuna magna, urethral, 480 Lambda, 17 Lambdoid suture, 17 Lamina cribrosa. 62 . fusca, 62 suprachoroidea, 62 Laminae of spine, 636 Laminectomy, 637 Langerhans, islets of, 427 Laryngotomy, 184, 187 Larynx, 179 excision of, 183 foreign bodies in, 187 ■ fracture of, 180 lymphatics of, 183, 198, 199 mucous membrane of, 182 Lateral curvature, 204 ligaments of knee-joint, 558 lithotomy, 462 muscles of abdomen, 341 ■ ■ sinus, 10, 33 ■ ventricles, 44 Leg, 576 — — • aching, 581 ■ ■ amputation of, 585 fascia of, 578 ■ ■ fractures of, 582 ■ gangrene of, 579 nerve supply of, 621 • pain in, 581 ■ rickets affecting bones of, 585 • skin of, 577 ■ surface anatomy of. 576 ■ ■ varicose veins of, 580 vessels of, 579 Lens, 69 artery to, 73 capsule of. 70, 72 Levator ani, 450, 491, 492 Levator cost arum muscles, 629 palati, 156 ■ palpebrae, 76 Ligamenta subflava, 637 Ligamentum patellae, 548, 559 pectinatum iridis, 72 " Lighterman's bottom," 507 Linea alba, 333, 338 ■ semilunaris. 379 transversa, 333 Lip, lower, lymphatics of, 198 Lipomata in deltoid region, 250 in Scarpa's triangle, 513 on buttocks, 505 rarity of, on face, 117 Lips, 143 Lisfranc's operation, 620 Litholapaxy. 462 Lithotomy, lateral, 462 in children, 464 ■ wounds in, 463 ■ median, 464 suprapubic, 465 Littre's operation, 408 Liver, 414 abscess of, 418 - diseases of, 441 ■ fixation of, 416 ■ in pyaemia, 418 ■ ■ nerve supply of, 441 ■ ■ operations on, 418 parietal surface of, 414 ptosis of, 416 • relations of, 415 to transverse colon, 417 rupture of, 416 ■ visceral surface of, 414 wounds of, 417 Lockjaw, 141 Longitudinal sinus, 33 Longus colli muscle, 629 Lordosis in hip-joint disease, 522 Lower limb, length of. 545 . . ■ lymphatics of, 517 . . . nerve supply of, 621 Lumbar abscesses, 367, 370 fascia, 356 — — glands, 517 — - - hernia. 364 ■ puncture, 641 . region, 369 . of spine, 630 . . . injuries in, 630, 645 triangle, 364 INDEX 6(55 Lumbar vertebrae, operation for caries of, 370 Lung, 213 apex of, in neck, 175 cavities, drainage of, 217 - — haemorrhage from, 216 - — ■ hernia of, 216 ■ hydatid cysts of, 217 . in neck. 213 relations of, to surface, 214 ■ root of, exposure of, 218 rupture of, 216 — - wounds of, 175, 216, 417 Lupus erythematosus, 98 Luschka's tonsil, 95 Lymphangioma cavernosum, 151 Lymphatic glands and vessels (see various regions) Microglossia, 151 Magendie, foramen of, 36 Malar bone, 127 fracture of, 127 Malleoli, 587 fractures of, in disloca- tion of foot, 599 " Mallet finger," 318 Mamma, 210 ■ arteries of, 213 ■ cancer of, 211 - — - capsule of, 211 ■ development of, 211 in Scarpa's triangle, 513 influence of ovary on, 491 lymphatics of, 211 nerves of, 211 supernumerary, 213 Mammary artery, internal, 210 Manubrium, 205 Mastication, muscles of. 141 Mastoid antrum, 91 cells, 93 abscess of, 91 « perforation of, 93 lymphatic glands, 198 ■ process, 93 Maxillae (see under Inferior and Superior) Meatus, auditory. 83 ■ of urethra, 479 Meatuses of nose, 105 Meckel's diverticulum, 340, 392 ■ ganglion, 120 space. 126 Median artery. 316 — - basilic vein, 276 Median cephalic vein. 276 ■ commissure of prostate, 473 ■ ■ lithotomy, 464 nerve, 293 paralysis of, 329 Mediastina, 221 — — abscess of, 221 glands of, 198 Mediotarsal joint, 608 amputation at, 619 Medulla spinalis 638 Meibomian glands, 77 Membrana tympani, 87 . ■ umbo of, 88 Meningeal artery, 9, 32 . haemorrhage, trephining for, 9 Meninges of brain, 31 ■ of spinal cord, 638, 639 Meningitis from abscess in ear, 84, 90 from inflammation of nasal fossae, 104 ■ spinal, from bed - sores, 640 Meningocele, 19, 100. 104 spinal, 651 Meningo-myelocele, 651 Mercier's bar, 471 Mesenteric arteries, 335, 442 hernia, 396 ■ plexus, 440 Mesentery, 373 holes in, 375 ■ imperfect attachments of, 375 length of. 358, 374 ■ of appendix, 401 prolapse of, 374 Meso-appendix. 401 Mesocolic hernia, 396 Mesocolon, 405 Mesogastric hernia, 396 Metacarpo-phalangeal joint of thumb, dislocations at, 322 Metatarsal bones, fractures of, 614 Metatarso - phalangeal joint, 588 Micturition in spinal injuries, 649 Mid-carpal joint, 317 Middle meningeal artery, 9, 32 . trephining for, 9 Mid-epigastric point, 334, 379 Mid-hypogastric point, 379 " Miner's elbow," 279 Monro, foramen of, 36 66G SURGICAL APPLIED ANATOMY Monro's point, 380 Morgagni, columns of, 497 Motor centres, 40 ■ paralysis in injuries to cord, 648 Mouth, 143 • cysts in floor of, 146 • dermoid cysts of, 146 ■ roof of, lymphatics of, 199 ■ thyroid cysts of, 146 Movable kidney, 431 Mucous membrane of anal canal, 497, 498 ■ ■ of bladder, 469 of duodenum, diver- ticula of, 395 of glans penis, 481 of larynx, 182 ■ ■ of nose, 107 of pharynx, 95, 159 ■ ■ of rectum, 494 ■ of urethra, 480 polyp of nose, 107 Miiller's muscle, 59 Multifidus spinas muscles, 629 Muscles, functional classifica- tion of, 317 Musculo-cutaneous nerve, 331 Musculo-spiral nerve. 268 ■ ■ paralysis of, 329 Myxcedema, 190 Myxomatous polyp of nose, 107 Nails of hand, 308 Nares. anterior, 100 posterior, 101 Nasal bones, 99 • fracture of, 99 ■ cavities, 100 blood supply of, 108 lymphatics of, 110 ■ nerves of, 109 of children, 102 - douche, 103 duct, 81, 105 fossa*. 103, 104 lymphatics of, 199 • polypi, 107 ■ ■ septum, 104 sinuses, 110 (see also Nose) Naso-pharyngeal tonsil, 159 Navel, 335, 339 ■ fistula at, 340 Neck, 165 ■ abscess of, 174 ■ air-sac in, 202 apex of lung in, 213 • blood-vessels of, 194 Neck, bony points of, 165 ■ fasciae of, 171 ■ fistulas of, 200 ■ hydrocele of, 202 lung in, 175, 213 lymphatic glands of, 196 198 middle line of, 166 ■ muscles of, 166 ■ nerves of. 169 ■ ribs in, 175 • side of, 166 ■ skin of, 170 surface anatomy of, 165 vessels of, 167, 178 wounds of, 177 Necrosis of cranial bones, 5 ■ of skull. 21 • of superior maxilla. 134 Nelaton's line, 503 Nephrectomy, 434 Nephro-lithotomy, 434 Nephrorrhaphy, 434 Nephrotomy, 434 Nerve-injecting, 509 Nerve-stretching, 509 Nerves (see various regions) division of (see various trunks) Neural arches, 650 Neuralgia, facial, 120 Neuritis, optic, 71 retrobulbar, 71 Nipple. 211 Nipples, supernumerary, 213 Nose, 98 ■ bleeding from, 108 cartilaginous part of, 99 ■ mucous membrane of, 107 skin of, 98 • (see also Nasal) Notch of Rivini, 88 Nuck, canal of, 359 Oblique, internal and external, muscles, 629 Obturator artery, abnormal, 362 canal, 3"63 ■ dislocation, 533, 536 fascia, 452 hernia, 363 nerve, 526, 624 Occipital artery, 168 — — bone at birth, 19 necrosis of, 149 • fontanelle, temporary, 20 lymphatic glands, 198 Occlusion of duodenum, 395 INDEX 667 Oculomotor nerves, paralysis of, 58 Odontoid process. 636 (Esophagotomy, 194 (Esophagus, 191 cancer of, 193 ■ foreign bodies in, 192 ; — -» malformations of, 193 nerve supply of, 193 . ■ relations of, 192 Olecranon, 274 epiphysis of, 288 . ■ fractures of, 288 Omega loop of colon, 407 Omental hernia, 373 ■ sac, 373 Omentum, great, 372 Omo-hyoid. 167 Onychia, 308 Ophthalmia, purulent, 79 . sympathetic, 69 Optic disc, 71 foramen, 71 nerve, 71 ■ neuritis, 71 ■ thalamus, 44 Ora serrata, 71 Orbicularis palpebrarum, 76 Orbit, 50 ■ abscess of, 54 ■ arteries of, 56 ■ fasciae of, 52 ■ foreign bodies in, 54 ■ fracture of, 50 lymphatics of, 199 ■ muscles of, 55 ■ nerves of, 56 . ■ paralysis of, 57 ■ pulsating tumours of, 56 relations of. 51 Orbital walls, relations of, 51 Os calcis, 587 dislocations of, 606 . fractures of, 613 epactal, 21 innominatum, 448 ■ magnum, dislocation of, 322 Osseous labyrinth. 97 Ossicles of ear, 88 Ovario-pelvic ligament, 491 Ovary, 490 ■ influence of, 491 ■ lymphatics of, 490 nerves of, 490 Pacinian bodies in foot, 590 in hand, 307 Palate, 153 Palate, cleft, 153 development of, 153 hard, 155 lymphatics of, 199 ■ soft, 156 Palmar {see Hand) Palmaris longus tendon, 300 Pampiniform plexus, 487 Pancreas, 425 relations of. 415, 425 Pancreatic ducts, 425, 426 Pannus, 61 Paracentesis, 208 of pericardium, 221 of thorax, 209 Paralysis in spinal injuries, '648 - of anterior crural nerve, 621 of brachial plexus, 324 of cervical sympathetic, 58 of Erb, 249 ' ; ■ . of external popliteal nerve, 624 of facial nerve, 131 of first division of fifth nerve, 58 of fourth nerve, 57 • of great sciatic nerve, 625 of internal popliteal nerve, 624 of median nerve. 329 of musculo-spiral nerve, 268. 329 of obturator nerve, 624 of oculo-motor nerves, 58 of orbital nerves, 57 - of sixth nerve, 57 of third nerve. 57 of ulnar nerve, 331 Parasinoids. 33 Parathyroid bodies, 190 Parietal bone, relations of, 21, 43 fissures, 21 Parieto-occipital fissure, 44 Paronychia, 308 Parotid abscess, 129 ■ fascia, 127 gland, 127, 132, 196 . nerve supply, 129 region, 127 — — • structures, 131 — - tumours, 132 Patella, 548, 560 ■ blood supply of, 569 ■ congenital absence of, 569 ■ development of, 569 668 SUKGICAL APPLIED ANATOMY Patella, dislocation of, 569 fractures of, 567 Patellar bursa, 553 • ligament, 548, 561 Pectoral glands, 212 Pectoralis major, 227 — — minor, 228 Pelvic abscess, 518 arch, 445 - colon, 407 multiple diverticula of mucous coat of, 409 fascia, 451 symphysis, 448 viscera, 453 fixation of, 453 ■ movements of, 453 Pelvis, 438, 445 floor of, 451 fractures of, 447 mechanism of, 445 — — nerves of, 499 renal, 428, 436 rickety, 446 small intestine in, 390 subserous tissue of, 454 Penile urethra, 477, 479 Penis, 480 lymphatics of, 481 ■ skin of, 480 nerves of, 500 vascularity of, 481 Perforating ulcer of foot. 591 Pericardium, 218 paracentesis of, 221 Pericranium, 5 Perineal fascia. 459 hernia, 364 Perinephritic abscess, 430 Perineum, 455 — - depth of, 457 — — male, 455 — — nerves of, 499 vessels of, 456 Periosteum, 5 Perirenal capsule, 431 • opening of, 436 Peritoneal communications, 375 spaces, 375 Peritoneum. 342. 371 fossae of, 354, 403 relations of bladder to, 465, 466, 467 watersheds of. 376 Peroneal artery. 577, 579 muscles, 577 — — nerve, 555 Peroneal tendon, 589 - tubercle, 588 Peroneus tendon, 589 Petit's triangle, 334 Petro-squamous suture, 90 vein, 90 Phalanges, fractures of, 614 Phalanx of great toe, disloca- tion of. 615 Phantom tumour, 340 Pharyngeal orifice, 95 pouches, 193 • recess, 95 tonsil, 95 Pharynx, 158 dimensions of, 158 excision of, 161 foreign bodies in, 158 lymphatics of, 199 mucous membrane of, 95, 159 • nerves of, 161 - relations of, 159 Phlebitis of femoral, 515 Photophobia, 67, 68 Phrenic nerve, 169, 217 Pigeon breast, 203 Piles, 495 Pinna, 82 (see also Ear) Pirogoff's amputation, 618 Pituitary body, 37 Plantar (see Foot) Plantaris muscle, rupture of, 579 tendon, rupture of, 579 Platysma myoides, 170 Pleura, 215 ■ nerve supply of, 217 opening of, 436 relations of, to surface, 214 wounds of, 175, 215 Plica vascularis, relations of, 356 Pneumatoceles, 94 Pneumothorax, 215, 216 Politzer's method of inflating middle ear, 94 Pollock's method of dividing muscles of palate. 157 Polypi, nasal, 107 Popliteal abscess, 554 bursse, 557 fascia, 554 ■ glands, 557 nerve, external, paralysis of, 624 internal, paralysis of, 624 INDEX 669 Popliteal nerves, 551. 554 ■ ■ space, 550 skin of, 553 vessels, 550. 555, 577 Portal vein, 373, 442 Postauricular lymphatic glands. 198 Posterior nares, 101 Postnasal growths, 160 Postnephric fascia. 431 Postpharyngeal abscess, 160 Potential spaces, 375 Pott's disease. 203, 637 fracture, 602 Poup art's ligament, 333 Preauricular lymphatic glands, 198 Prenephric fascia, 431 Preputial ocelli, 482 Processus funicularis. 357 vaginalis, 351, 357 relations of, 356 Pronation, 294 Prostate, 462, 473 — — abscess of, 475 capsule of, 474 commissures of, 473 hypertrophy of, 475 lobes of, 473 ■ lymphatics of, 476 muscles of, 462 nerves of, 475 ■ secretion of. 474 ■ sheath of, 462, 474 Prostatectomy, 476 Prostatic ducts, 474 ■ urethra, 477. 478 . venous plexus, 462 Prostatitis, 475 Protopathic sensibility, 124, 330 Pruritus ani, 497 Psoas abscess, 368, 513 ■ ■ muscle, 437. 513. 629 Pterion, 42 Pterygoid muscle, external, 138 Pterygo-maxillary ligament, 146 Ptosis of eyelid. 57 ■ of liver, 416 of stomach, 382 Pubes, dislocation upon, 533. 537 Pubic commissure of pros- tate, 473 spine, 333 Pudendal hernia, 364, 488 Pudic artery, 504 Pulmonary apoplexy, 216 Pupillary membrane, 64 Purulent ophthalmia, 79 Pyaemia, liver in, 418 Pyloric orifice, 381 Pyloroplasty, 389 Pylorus, 382, 387 — — cancer of, 427 . hypertrophy of, 387 • resection of, 388 Quadratus lumborum muscle, 629 Quadriceps of thigh. 542 Radial artery, 292, 315, 316 ■ nerve, 329 Radio-carpal joint, 317 Radio-humeral joint, 274 Radius, dislocation of, 282 fractures of, 289, 296 surface markings of, 292 Ranula. 145 — — acute, 146 Rectal commissure of pros- tate, 473 Recti, divarication of, 338 Rectocele, vaginal. 489 Recto-vaginal fistula, 489 wall, rupture of. 498 Recto-vesical pouch, 468, 491 Rectum, 406, 491 ■ attachments of, 494 cancer of, 496 congenital absence of, 408 deficiency of, 408 distension of, 493 excision of, 493 - folds of, 495 ■ foreign bodies in. 493 in infant, 409 introduction of hand into, 493 lymphatics of, 496 - mucous membrane of, 494 — nerve supply of. 497 — - serous membrane of, 491 valves of, 495 « vessels of. 495 Rectus abdominis muscle, 338, 340, 629 Recurrent laryngeal nerve, 191 Referred pain, 140, 328, 329, 348, 441, 581, 598 Reflex contraction, 341 Renal abscess, 431 ■ artery, 436 pelvis, 428, 436 670 SURGICAL APPLIED ANATOMY Renal plexus, 432 ■ tumours, 436 • {see also Kidney) Respiration in spinal injuries, 648 Retina, 70 ■ vessels of, 65, 66 Retrobulbar neuritis, 71 Retrocsecal fossa, 403 Retroperitoneal hernia, 396 Retropharyngeal abscess, 368 Retropubic space, 467 Retzius, foramen of, 37 Rhinoplasty, 99 Rhinoscopy, 101 Ribs, 206 > cervical, 175 effect of rickets on, 208 excision of, 209 fractures of, 207 Rickets, effect of, on pelvis, 446 __ on ribs, 208 — ■ on skull, 18 ■ on tibia, 585 Rickety pelvis. 446 " — — rosary," 208 Rider's bone, 515 sprains, 514 Riedel's lobe, 416 Rima glottidis, 166, 181 Rivini, notch of, 88 Rolando, fisure of, 41 Rontgen rays in intrathoracic disease, 221 Rosenmuller. fossa of, 95 Rouge's operation, 101 Sacculated bladder, 470 Sacro-coccygeal joint, 450 tumours, 450 Sacro-iliac synchondrosis, 445, 449 nerve relations of, 449 Sacro-sciatic notch, 440 Sacrum, 445 dislocation of, 449 Sagittal fontanelle, 21 suture, 17 Salivary fistulae, 133 Santorini, duct of, 425 fissures of, 84 Saphenous nerve, 551, 577 opening, 361, 512 veins, 512, 516, 551, 557, 577 Sarcomatous polyp of nose, 108 Sartorius muscle, 511, 514 Scalene muscles, 167 Scalp, abscess of, 6 blood tumours of, 7 ■ blood-vessels of, 13 connective tissue of, 3 cysts of, 2 - — dangerous area of, 3 erysipelas of, 14 fascia of, 1, 6 fatty tissue in, 2 haematomata of, 7 • lymphatics of, 16, 198 - mobility of. 3, 4 nerves of, 13, 16 ■ sebaceous tumours of, 2 — — - skin of, 1 subcutaneous tissue of, 1 suppuration in, 6 — — vascularity of, 4 wounds of, 3 bleeding from, 4 Scaphoid, dislocation of, 605 - fracture of, 321 Scapula, 224, 225, 239 — - excision of, 242 fracture of. 240 ■ of body of. 241 through surgical neck of, 241 movements of, 239 • tumours of. 242 . " winging " of. 240 Scarpa's fascia, 362 triangle, 511 blood-vessels of, 515 bursa about, 514 fascia of, 513 lymphatic glands of, 512, 516 mamma in, 513 muscles of, 514 nerves of, 516 ■ — skin of, 512 surface anatomy of, 511 — — ■ • testicle in, 513 Schlemm, canal of, 7 9 . 73 Sciatic artery. 504, 507 ■ hernia, 364 nerve, great, 504, 508 paralysis of, 625 relations of, 508 - notch, dislocation into, 533 Sciatica, 509 Sclerotic, 61 Scoliosis, 204, 629 Scrotum, 482 and oedema, 483 INDEX 671 Scrotum, application of leeches to, 483 lymphatics of, 485 — — ■ rugae on surface of, 483 skin of. 482 nerves of, 500 subcutaneous tissue of, 483 Sebaceous tumours of scalp. 2 Semilunar cartilages, disloca- tion of, 563 • > fixation of, 564 ■ ■ movements of. 564 Semimembranosus tendon, 550 Semispinalis muscle, 629 Semitendinosus tendon, 550 Sensori-motor areas of brain, 40, 45 Sensory nerve, 123 - paralysis in injuries to cord, 648 Septum of nose, 104 Sesamoid bones, 615 Short-circuiting. 397, 412 Shoulder, 224 ■ surface anatomy of, 224 Shoulder-joint. 251 ■ amputation at, 262 bursse about, 252 ■ capsule of. 252 disease of, 253 ■ dislocation of, 255, 257, 258, 259 — common features of, 256 ■ special anatomy of all forms of, 257 fractures about, 260 ■ relations of, 243 Sibson's fascia, 175 Sigaultean operation, 448 Sigmoid flexure, 406 - hernia, 407 — - mesocolon, 407 Sinus, accessory, 110 cavernous, 33 frontal. 110 lateral, 33 ■ pocularis, 477 ■ sphenoidal. 113 superior longitudinal, 33 Sinuses, nasal. 110 • venous, 32 Sixth nerve, paralysis of, 57 Skull, 17 ■ abnormalities of, 19 ■ at birth, 20, 30 cap, thickness of, 30 deformities of, 19 Skull, development of, 18 effect of rickets on, 18 emissary veins of, 13 . fractures of, 22. 26, 27 necrosis of, 5. 2 J of infant, 17. 23, 30 pillars of, 24 soft parts covering, 1 ■ sutures of, 17, 19, 29 closure of, 24 • separation of, 29 ■ thickness of, 30 ■ trephining, 9 ■ venous tumours of, 15 Smith's (Stephen) operation, 575 Soft palate, 155 blood supply of, 157 ■ ■ muscles of. 157 - nerves of, 158 Solar plexus, 440 Soleus muscle, 577, 579 Spermatic artery, 487 cord, 486 — — ■ • arteries of, 487 ■ plexus of veins, 487 Sphenoidal sinus, 113 Sphincter ani, 450, 493 Spina bifida, 650 Spinal accessory nerve, 169 - analgesia, 642 — cord, 638 ■ — — blood supply of, 643 ■ concussion of, 643 — — contusion and crush- ing of, 645 loss of motion due to injury of. 648 of sensation due to injury of. 648 ■ ■ operations on, 651 ■ protection of. 633 ■ — wounds of, 179, 642, 643 • dura mater, 639 ■ injuries and defsecation, 649 and micturition, 649 ■ and respiration, 643 ■ and vomiting, 650 membranes, sections of, 642, 643 ■ meninges, 638, 639 • meningitis. 639. 640 meningocele, 651 ■ muscles, 629 ■ nerves, distribution of, 625, 646 672 SURGICAL APPLIED ANATOMY Spinal nerves, points of exit of, from verte- bral canal, 647 . , . , f origin of, 647 Spine, 627 anterior superior, 333 ■ caries of, 637 curvature of, 204, 627 • dislocations of, 632 fracture-dislocations of, 634 . fractures of, 632 how maintained erect, 629 -- — kyphosis of, 204 ■ mechanism of, 632 movements of, 628 . of infant, 628 ■ pubic, 333 ■ scoliosis of, 204, 629 • sprains of, 630 ■ trephining, 637 Spino-umbilical line, 380 Spinous processes, fracture of, 636 Splay-foot. 610 Spleen, 423 capsule of, 424 dislocation of, 423 enlarged, 424 extirpation of, 425 injuries to, 424 relations of, 423 ■ rupture of, 424 Stenson's duct, 132 Stercoral ulcers, 400 Sterno-clavicular joint, 234 — disease of, 235 dislocations of, 236 . movements of, 235 Sterno-ensiform line, 379 ■ point, 219, 334, 379 Sterno-manubrial joint, 205, 218 Sterno-mastoid muscle, 166, 170 Ster no-xiphoid joint, 205 Sternum, 205 ■ caries of, 206 fracture of, 205 ■ ■ gummatous periostitis of, 206 ■ holes in, 206 - — - trephining, 206 Stomach, 381 ■ cancer of, 223, 388 ■ dilatation of, 382 diseases of, 441 ■ ■ displacement of, 379 of. Stomach, fistulae of, 384 foreign bodies in, 385 functional divisions 382 ■ lymphatics of, 385 operations on, 3815, 389 — — ptosis of, 382 relations of, 381 shape of, 382 • wounds of, 384 Stovaine, injection of, into subarachnoid space, 642 Strabismus, 55, 57 Strangulated bowel, 340, 393 • hernia. 407 testicle, 484 Stylo-maxillary ligament, 172 Subacromial bursa, 252 Subarachnoid space, 34. 640 ■ injection of stovaine into, 642 Subastragaloid amputations, 621 ■ dislocations of foot, 607 ■ joint, 605 Subclavian artery, 168, 195 ■ vein, 169, 229 Subclavicular fossa, 226 Subclavius muscle, 230 Subcoracoid dislocation of humerus, 257 Subcutaneous tissue of eye- lids, 76 ■ of scalp, 1 Subdural space, 34, 640 Subfascial abscess, 353 Subglenoid dislocation humerus, 259 Sublingual gland, 144 ■ papillae, 144 Subluxation of jaw. 138 Submaxillary Ivmphatic glands, 145, 150, 196 Subperitoneal connective tis- sue, 342 Subscapular glands, 212 Subserous tissue of pelvis, 454 Subspinous dislocation of humerus, 259 Superficial cervical glands, 198 . nerve, 169 • eoigastric vein, 335 Superior longitudinal sinus, 33 • maxilla, 133 ■ antrum of. 113 . cleft of. 153 ■ excision of, 134 — ■ fracture of, 133 of INDEX 673 Superior maxilla, necrosis of, 134 ■ nerves of, 140 • mesenteric artery, 335 . plexus. 440 thyroid artery, 167, 191 vena cava, 220 Supernumerary auricles, 202 mamma. 213 . in Scarpa's tri- angle, 513 nipples, 213 Supination, 294 Supinator longus, 275 Suppuration in hip-joint, 520 in scalp, 6 Supra-acromial nerve, 169 Supraclavicular nerves, 169, 229 Supracondyloid process, 268, 278 Suprahyoid lymphatic glands, 196 Supra-orbital foramen, 120 Suprapubic lithotomy, 465 Suprarenal artery, 335 - bodies, 437 • tumours, 437 Suprascapular artery, 169 Suprasternal nerve. 169 Suspensory ligament, 53, 70 Sustentaculum tali, 605 . fracture of, 614 Suture, lambdoid, 17 ■ sagittal, 17 Sutures of skull, 17, 19, 29 . closure of, 24 . separation of, 29 Sycosis of eyelids, 77 Sylvius, fissure of. 41 Symblepharon, 78 Syme's amputation, 617 Sympathetic ophthalmia, 69 ■ pains, 441 Symphysis of pelvis, 448 Synostosis of skull, 24 Synovial cavities of foot, 617 . of hand, 322 membrane of knee-joint, 560 sacs of hand, 312 sheaths of ankle. 592, 593 ■ of hand, 312 Synovitis, acute, in hip- joint, 520 ■ in knee-joint, 562 Syphilis, hereditary. 18 Syringo-myelocele, 651 Systolic empty bladder. 466 Tabatiere anatomique, 305 Tagliacozzi's operation, 265 Talipes calcaneus, 608 • cavus. 591 — — equinus, 608 mixed forms of, 610 — — - valgus, 609 . varus, 607, 609 Talma-Morrison operation, 443 Tarsal bones, 613 . ■ dislocations of, 613 . fractures of, 613 ossification of, 615 • plate, 76 Tarsectomy, 610 Tarso-metatarsal joint, 620 Tarsus (see Tarsal bones) Taxis, 360 Teeth, 141 alveolar abscesses of, 142 ■ caries of, 140 ■ permanent, 141 • temporary, 141 ■ wisdom. 142 Tegmen tympani, 11 Temporal convolution, in- ferior, 44 ■ fascia, 8 fossa, abscesses in, 8 • region, 8 ■ > trephining in, 8 Temporo - maxillary articula- tion, 137 • ■ dislocation at, 137 - ■ ■ movements of, 137 Temporo-sphenoidal abscess, 10 Tendo Achillis. 579, 588 ■ oculi, 79 Tenon, capsule of, 52 Tenotomy at ankle, 588 Tensor palati, 156 Testicle, 355, 484 ■ descent of, 355, 484 in Scarpa's triangle, 513 ■ inversion of, 485 ■ lymphatics of, 485 nerve supply of, 485, 501 — — retained, 484 • strangulated, 484 ■ torsion of. 484 « tunic of, 485 - vessels of, 487 Thecal abscess. 314 Thenar eminence, 302 Thigh, 540 amputation of, 546 ■ ■ at hip- joint, 538 ■ fascia of, 541 674 SURGICAL APPLIED ANATOMY Thigh, femoral artery of, 543 fracture of, 544 ■ shortening of limb after, 545 integuments of, 541 ■ muscles of, 539, 542 rupture of, 542 — — - nerves of, 539 - skin of, 541 surface anatomy of, 540 Third nerve, paralysis of. 57 Thoracic duct, 199, 223, 443 wounds of, 443 Thoracoplasty, 209 Thorax, 203 deformities of, 204 paracentesis of, 208 viscera of, 213 ■ walls of. 203 — — wounds of, 216 Throat, cut, 177 Thumb, amputation of, 324 ■ dislocation of, 322 - movements of, 331 Thymus, 186 Thyro-glossal duct, 189 Thyro-hyoid space, wounds of, 177 Thyroid artery, superior, 167 ■ body, 188 ■ accessory glands of, 189 ■ atrophy of, 190 development of, 189 ■ in tracheotomy, 186 isthmus of, 186. 189 - ■ lymphatics of, 190 ■ cartilage, 180 ■ cysts, congenital, 146 dislocation, 533, 536 Thyroidea ima artery, 191 Thyrotomy, 183 Tibia, 582 and fibula, fractures of, 582, 599 — — epiphysis of, 574 — - fractures of, 572, 584. 599 — — ossification of, 573 — — ■ rickets affecting, 585 • upper end of. 572 Tibial vessels, 577, 579 Tibialis anticus muscle, 576 . ■ tendon, 588 ■ posticus tendon, 589 Toe, great, dislocation of, 615 Tongue, 147 ■ accessory glands of. 151 blood supply of, 148 cancer of. 151 Tongue, epithelium of, 148 ■ excision of, 152 lymphatics of, 150, 198 nerves of, 148 ■ removal of, 153 Tongue-tie, 147 Tonsil, 161 > blood supply of, 164 — — - hypertrophy of, 161 causing deafness, 163 ■ lingual, 150 Luschka's, 95 lymphatics of, 161, 199 malignant growths of, 164 naso-pharyngeal, 159 ■ palatinus. 155 — — pharyngeal, 95 Trachea, 179, 184, 217 ■ foreign bodies in, 187, 218 • wounds of, 178 Tracheotomy, 184. 185 / Transpyloric plane, 379 Transversalis fascia, 366 Transverse cervical artery, 169i • ■ colon, 405 process of atlas, 165 of cervical vertebrae, 165 of lumbar vertebra}, 636 Trapezium, 302 Traumatic aneurysms, 56 Trendelenburg's operation, 450 Trephining. 9, 637 .. for cerebral abscess, 9 ■ • tumour, 11 for meningeal artery, 9 ■ haemorrhage. 9 in temporal region, 8 Triangular ligament of ure- thra, 460 Trigone, 469 Tripodism, 450 Trismus, 141 Tuber ischii, 445, 503 Tumour, blood, of scalp, 7 . ■ on pinna, 85 cerebral, trephining for, 11 ■ fluid, of vertebral canal, 650 . in gall-bladder, 422 ■ parotid, 132 . phantom, 340 • renal, 436 - sacro-coccygeal. 450 ■ scapular, 242 • suprarenal, 437 venous, of skull, 15 INDEX 675 Turl Tunica abdoininalis, 336 albuginea, 485 vaginalis, 357 Turbinate body, 107 ■ process, 106 Tympanites, 392 Tympanum, 89 attic of, 88, 91 ■ blood supply of, 96 > lymphatics of, 96 Typhlitis, 400, 401 Ulcer, perforating, of foot, 591 Ulna, dislocation of. 282 ■ fracture of, 297 Ulnar artery, 315 nerve, 278 • ■ ■ paralysis of, 331 ■ ■ section of, 330 vein, 276 Jmbilical fistula, 340 hernia, 339, 364 — line, 379 Jmbilicus. 333 ■ fibrous ring of, 339 vessels of, 339 Umbo of membrana tympani, 88 Upper limb, epiphyses of, 331 nerve supply of, 324 Urachus, 340, 353 Ureter, 437, 471 distension of, 438, 471 ■ kinking of, 433 ■ radiographic examina- tion of, 438 relations of, 437 resection of. 440 ■ rupture of, 438 Urethra, female, 480 ■ male, 476 ■ catheterism of, 477 • curve of, 476 ■ ■ narrowest parts of, 479 ■ • rupture of, 480 ■ spasmodic stricture of, 479 ■ membranous, 460. 479 • mucous membrane of, 480 nerve supply of, 500 • penile, 477, 479 • prostatic, 477, 478; Urethral canal. 478 • triangle, 455, 459 Uterus, 489 artery of, 490 - cervix of, 490 Uterus, lymphatics of, 490 ■ wounds of, 490 Vagina, 489 wounds of, 489 Vaginal cystocele, 489 ■ enterocele, 489 ■ process, 355 — _ of peritoneum. 351 ■ rectocele, 489 Valsalva's method of inflating middle ear, 94 Valves in veins, 196 Varicocele, 488 Varicose veins, 487, 515, 580 Vas aberrans, 268 • deferens, 486 ■ rupture of, 486 Vater, ampulla of, 420, 425, 426 Veins, air in, 195 ■ emissary, of skull, 13 of Galen, 37 — — valves in, 196 (see also various regions) Venesection at elbow, 276 Venous sinuses, 32 tumours of skull, 15 Vertebra prominens, 165 Vertebrae, caries of, 370 ■ dislocation of, 633 fracture of. 633 — — fracture - dislocation of, 634 ■ movements of, 628 Vertebral artery, 195 ■ canal, congenital mal- formations of, 650 fluid tumour of, 650 — — points of exit of nerves from, 647 ■ column, 627 ■ sprains of, 630 ■ (see also Spine) Vesico-vaginal fistula, 489 Viscera, abdominal, nerve sup- ply of, 440 thoracic, 213 Visceral nerves, 348 ' supports, 380 Visceroptosis, 378 Viscus, dilatation of, 383 Vitello-intestinal duct, 340, 392 Vitreous humour, 71, 73 foreign bodies in, 73 " table," 25 Vocal cords, 181 Vomiting, severe, in spinal in- juries, 650 Vulva, 466 676 SURGICAL APPLIED ANATOMY " Weaver's bottom," 507 Wharton's duct, 144 White line at anus, 498 ■ in pelvic fascia, 452 Whitlow, 314 Winged scapula, 240 Winslow, foramen of. 376 Wirsung, duct of. 425 Wormian bones. 21 Wrist, 300 Wrist-joint, 301 Wrist-joint, amputation at, 323 ■ dislocations at, 321 • fractures about. 318 movements of, 317 strength of, 316 surface anatomy of, 300 Wry-neck, 170 Zygoma as guide to struc tures, 12 ■ fracture of, 12 Printed bv Cajssell & Company, Limited, La Belle Sauvage, London, E.G. UNIVERSITY OF CALIFORNIA MEDICAL SCHOOL LIBRARY THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW Books not returned on time are subject to a fine of 50c per volume after the third day overdue, increasing to $1.00 per volume after the sixth day. Books not in de- mand may be renewed if application is made before expi- ration of loan period. Library o! the University of California Medical School and Hospitals