www.e-neurospine.org S15 Neurospine Endoscopic Spinal Surgery, 2nd Issue The technical advancement of endoscopic spine surgery is inexorable and fascinating. Indications are expanding, the number of surgeons who are beyond their individual learn- ing curves is increasing. Technical skills especially of the younger generation of spine sur- geons are getting better and better. The instruments available for different surgical tecniques are getting more and more sophisticated. This is the second issue of a NASS-Neurospine Visualized Endoscopic Spine Surgery pub- lication on endoscopic spine surgery which contains 19 papers/video technical tutorials, 10 of which I had the pleasure to read/view. There is an introductory paper which describes the clinical and economic advantages of endoscopic spine surgery with a focus on the benefits for patients life quality. Two articles focus a on new indications of endoscopic surgery in the cervical spine. I be- lieve, that the very interesting transcervical retropharyngeal approach to the odontologisch process has the potential to replace transoral surgery. A case report which describes multisegmental full-endoscopic posterior drainage of cer- vical epidural abscess opened a new perspective to deal with this severe disease. For the treatment of central spinal stenosis, the inside-out full-endoscopic cross-over ap- proach is presented including the 1 year clinical follow-up of 127 patients. Even though there is a considerable learning curve, I believe that this technique can produce clinical re- sults comparable to the standard microsurgical cross-over decompression in degenerative lumbar spinal stenosis. Four papers/videos in this issue focus on biportal endoscopic approaches for lumbar de- compression, discectomy, minimally invasive transformational lumbar inter body fusion and even revision surgery e.g., in case of postoperative epidural hematoma. This technical variation of posterior full-endoscopic approaches allows for wider fields of endoscopic vi- sion and a perfect way of triangular surgery such as in knee-arthroscopic techniques. Espe- cially for fusion surgery this might be a promising technique. The clinical application in the cervical spine is described for bilateral foraminotomy in cases with bilateral radiculopathies. Last but not least another microsurgical approach has been ‘transformed’ to a full-endo- scopic technique: the translaminar approach for cranial migrated disc herniations. This is a technically demanding approach but I believe that when it is performed with full-endoscop- ic technique it can be even less invasive as compared to microsurgery. In summary, the papers I could read are excellent examples of the ongoing technical evo- lution (revolution?) of endoscopic spine surgery and I congratulate the authors for their pi- oneering work. Neurospine 2020;17(Suppl 1):S15-16. https://doi.org/10.14245/ns.2040418.209 Neurospine eISSN 2586-6591 pISSN 2586-6583 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecom- mons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Copyright © 2020 by the Korean Spinal Neurosurgery Society Editorial Corresponding Author Michael Mayer https://orcid.org/0000-0003-2555-8126 Schön Klinik München Harlaching, Harlachinger Str. 51, D-81547 München, Germany E-mail: michaelmayer3004@me.com See the article “Inside-Out Approach of Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression: A Detailed Technical Description, Rationale and Outcomes” via https://doi. org/10.14245/ns.2040196.098. http://crossmark.crossref.org/dialog/?doi=10.14245/ns.2040418.209&domain=pdf&date_stamp=2020-07-31 Neurospine Endoscopic Spinal Surgery, 2nd IssueMayer M Neurospine 2020;17(Suppl 1):S15-16.S16 www.e-neurospine.org Title: Accordionist Artist: Pablo Picasso Year: 1911 Picasso’s still life Carafe, Jug, and Fruit Bowl, painted two summers before, shows an earlier stage of this style. Surfaces are broken into sharply defined planes but are not yet complexly fragmented; forms still retain an illusion of volume; and perspective, though dramatically shortened, is not obliterated. At its climax, Braque and Picasso brought Analytic Cubism almost to the point of complete abstraction. Among such works is Picasso’s Accordionist, a baffling composition that one of its former owners mistook for a landscape because of the inscription “Céret” on the reverse. With diligence, one can distinguish the general outlines of the seated accordionist, denoted by a series of shifting vertically aligned triangular planes, semicircular shapes, and right angles; the centrally located folds of the accordion and its keys; and, in the lower portion of the canvas, the volutes of an armchair. But Picasso’s elusive references to recognizable forms and objects cannot always be precisely identified and, as the Museum of Modern Art’s founding director Alfred H. Barr, Jr. observed, “the mysterious tension between painted image and ‘reality’ remains.” More information: https://www.guggenheim.org/artwork/3426 © 2020 - Succession Pablo Picasso - SACK (Korea)