Effect of Sub-axial Cervical Lateral Mass Screw Fixation on Functional Outcome in Patients with Cervical Spondylotic Myelopathy

BACKGROUND: The role of laminectomy alone as an etiology of postoperative cervical instability is well known. Cervical sagittal malalignment of the spine has been linked to unfavorable functional outcome, so the effect of restoration of sagittal spinal alignment on functional outcomes and treatment effectiveness has recently gained attention. OBJECTIVE: This is a prospective observational study aims to observe the possible relation between cervical sagittal alignment and functional outcomes following sub-axial cervical lateral mass screw fixation in patients with cervical spondylotic myelopathy. PATIENTS AND METHODS: Thirty patients were included in this study all suffering from cervical spondylotic mylopathy (CSM) who underwent cervical laminectomy and screw-rod fixation and followed up over 6 months. Functional outcome accessed using Nurick myelopathy score and neck disability index (NDI)?. We also used the Cobb angle method (C(2)–C(7)) as a parameter for radiographic assessment of the cervical sagittal alignment which was measured preoperatively and postoperatively on lateral neutral views of cervical X-ray. RESULTS: All the patients underwent cervical laminectomy and fixation in a range of 3–5 levels. Two intraoperative facet fractures and four facet joint violations were observed. All the patients were followed-up for at least 6 months. There were significant improvements of the motor power (88.5%), Nurick score (90%), and NDI (90%) postoperatively. The mean preoperative Cobb angle for all patients was −8.51° ± 14.07° standard deviation (SD) which changed to −10.29 ± 12.43 SD at the end of follow-up. CONCLUSION: Combing posterior decompression with lateral mass screw– rod in patients with CSM was effective in improving or at least maintaining cervical alignment with the good functional outcome.