Muscle-Preserving Selective Laminectomy Maintained the Compensatory Mechanism of Cervical Lordosis After Surgery. Issue 8 (15th April 2018)

• Record Type: Journal Article
• Authors: Nori, Satoshi; Shiraishi, Tateru; Aoyama, Ryoma; Ninomiya, Ken; Yamane, Junichi; Kitamura, Kazuya; Ueda, Seiji
• Is Part Of: Spine. Volume 43:Issue 8(2018)
• Publication Date: 2018-04-15
• Subjects: C7 slope -- cervical alignment -- cervical compressive myelopathy -- cervical lordosis -- cervical sagittal balance -- cervical spondylotic myelopathy -- compensatory mechanism -- laminectomy -- laminoplasty -- minimally invasive surgery -- muscle preservation -- ossification of posterior longitudinal ligament -- sagittal vertical axis -- selective laminectomy; Spine -- Abnormalities -- Periodicals; Spine -- Diseases -- Periodicals; Spine -- Surgery -- Periodicals; 616.73005
• DOI: 10.1097/BRS.0000000000002359
• Languages: English
• ISSNs: 0362-2436

Abstract

Abstract : Study Design: A retrospective single-center study. Objective: The aim of this study was to evaluate the compensatory mechanism of cervical lordosis (CL), the changes in cervical sagittal alignment, and range of motion (ROM) after muscle-preserving selective laminectomy (SL). Summary of Background Data: CL increases as a compensatory mechanism for the adjustment of cervical sagittal balance or horizontal gaze. However, laminoplasty invades this mechanism and causes kyphosis in higher T1 (C7) slope patients. Methods: SL is a posterior surgery selecting the decompression laminae without disturbing the extensor musculature and facet joints. The clinical features and radiological findings of 125 cervical compressive myelopathy patients who underwent C6 single-level SL, C5-C6 two consecutive levels SL, C4-C6 three consecutive levels SL, and C3-C6 four consecutive levels SL were enrolled. Cervical spine lateral radiography was performed before surgery and at the final follow-up. The patients were divided into two groups according to the preoperative C7 slope. Postoperative cervical alignment change was compared between the higher and lower C7 slope groups. Subsequently, pre- and postoperative cervical alignment and cervical ROM were analyzed according to the number of consecutive laminae surgically treated. Results: Patients with higher C7 slope had greater lordotic cervical alignment and larger C2-C7 sagittal vertical axis (SVA) pre- and postoperatively. No kyphotic alignment change was observed, even in the higher C7 slope group. C6 SL and C5-C6 SL did not affect C2-C7 angle, and did not increase C2-C7 SVA after surgery. Although C4-C6 SL and C3-C6 SL demonstrated postoperative slight increase in C2-C7 SVA, C2-C7 angle never decreased after surgery. Cervical ROM slightly reduced in the C4-C6 SL and C3-C6 SL groups; however, no reduction of ROM was observed in the C6 SL and C5-C6 SL groups. Conclusion: SL preserved the inherent compensatory CL that had been observed preoperatively and maintained cervical sagittal balance after surgery. Level of Evidence: 4