Efficacy of Posterior Segmental Decompression Surgery for Pincer Mechanism in Cervical Spondylotic Myelopathy: A Retrospective Case-controlled Study Using Propensity Score Matching

Study Design.Retrospective case-controlled study using propensity score matching.Objective.We aimed to evaluate the efficacy of cervical microendoscopic laminoplasty (CMEL) of the articular segment in patients with cervical spondylotic myelopathy (CSM) by comparing the clinical results of CMEL with conventional expansive laminoplasty (ELAP) for CSM.Summary of Background Data.A total of 259 patients undergoing CMEL or ELAP surgery for CSM at authors' institute were reviewed.Methods.The patients were matched according to calculated propensity scores in a logistic regression model adjusted for age, sex, and preoperative severity of disorders and divided into the CMEL and ELAP groups. All patients were followed postoperatively for more than 2 years. The preoperative and 2-year follow-up evaluations included neurological assessment (Japanese Orthopaedic Association [JOA] score), recovery rates, the JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), axial pain (visual analog scale), and the Short Form 36 questionnaire (SF-36).Results.There were 71 patients in each group (47 males and 24 females each). The mean ages of the CMEL and ELAP groups were 63.8 and 62.8 years, respectively. There was no significant difference in the preoperative JOA score between groups. The mean numbers of surgically affected levels in the ELAP and CMEL groups were 3.2 and 1.8 discs, respectively (P0.05). The groups exhibited similar recoveries of JOA, JOACMEQ, and SF-36 scores postoperatively. Sagittal alignment was maintained in both groups. However, postoperative neck axial complaints were significantly reduced in the CMEL group.Conclusion.CMEL may be a useful and effective surgical procedure for CSM, providing similar results as ELAP. CMEL for CSM is indicated for posterior decompression of the articular segment along with a pincer mechanism. This minimally invasive technique may have potential advantages compared with conventional ELAP, and may provide an alternative surgical option.Level of Evidence: 4