Hirabayashi Shigeru, Kitagawa Tomoaki, Yamamoto Iwao, Yamada Kazuaki, Kawano Hirotaka
Department of Orthopaedic Surgery, Teikyo University Hospital, Tokyo, Japan.
Spine Surg Relat Res. 2018 Feb 28;2(3):169-176. doi: 10.22603/ssrr.2017-0044. eCollection 2018.
Various methods via anterior or posterior approach with or without spinal stabilization have been performed in accordance with the level and configuration of ossification of the posterior longitudinal ligament (OPLL) as the decompression surgery for thoracic myelopathy due to OPLL. Among them, anterior decompression at the middle thoracic level (T4/T5-T7/T8) is especially difficult to perform because of the special anatomical structures, where the spinal alignment is kyphotic and the thoracic cage containing circulatory-respiratory organs exist nearby. Of the anterior decompression procedures at this level, the posterior approach has various advantages compared to the anterior one. In the anterior approach, the procedure is complicated and the effect of decompression of the spinal cord can be obtained only by direct resection or anterior floating of the OPLL. However, complications such as spinal cord injury and dural tear are most likely to occur at that time. On the contrary, in the posterior approach, the procedure is simple, and various options to obtain decompression can be selected from, these are, laminectomy, laminoplasty, dekyphosis surgery, staged decompression surgery (Tsuzuki's method), circumferential decompression via posterior approach alone (Ohtsuka's method), and circumferential decompression via combined posterior and anterior approaches (Tomita's method). Among them, in laminectomy, laminoplasty, and dekyphosis surgery, anterior decompression can be obtained to some extent without performing direct procedure on the OPLL. In Ohtsuka's method, complete decompression can be obtained via posterior approach alone, although it is somewhat technically demanding. It is preferable to drop the shaved down and separated OPLL anteriorly instead of trying to remove it completely to avoid complications, especially in patients with severe adhesion between the dura mater and OPLL.
根据后纵韧带骨化（OPLL）的部位及形态，针对OPLL所致胸段脊髓病的减压手术，已开展了多种经前路或后路的手术方法，有无脊髓固定均可。其中，胸段中节段（T4/T5 - T7/T8）的前路减压尤为困难，因其解剖结构特殊，该部位脊柱呈后凸畸形，且附近有包含循环呼吸器官的胸廓。在此节段的前路减压手术中，后路手术相比前路具有多种优势。在前路手术中，操作复杂，脊髓减压效果只能通过直接切除OPLL或使其前路漂浮来实现。然而，此时最易发生脊髓损伤和硬脊膜撕裂等并发症。相反，后路手术操作简单，可选择多种减压方式，包括椎板切除术、椎板成形术、矫正后凸手术、分期减压手术（铃木法）、单纯后路环形减压（大冢法）以及前后联合入路环形减压（富田法）。其中，在椎板切除术、椎板成形术和矫正后凸手术中，无需对OPLL进行直接操作即可在一定程度上实现前路减压。在大冢法中，尽管技术要求较高，但单纯后路即可实现完全减压。为避免并发症，尤其是硬脊膜与OPLL严重粘连的患者，最好将削薄并分离的OPLL向前移位，而非试图完全切除。
