Impact of Concomitant Cervical Anterolisthesis on Surgical Outcomes in Cervical Spondylotic Myelopathy: A Multicenter Prospective Study.

Study DesignMulticenter prospective cohort study.ObjectivesThis study aimed to determine whether concomitant cervical anterolisthesis influences surgical outcomes in patients with cervical spondylotic myelopathy (CSM).MethodsA total of 691 CSM patients were enrolled and classified into those with anterolisthesis ≥ 2 mm (Slip group, n=95) and those without measurable slip (Non-slip group, n=596). Patients underwent surgical treatment as indicated and were followed for 2 years. Cervical alignment, C2-7 ROM, JOA scores, JOACMEQ domains, and SF-36 scores were assessed. Clinical outcomes were compared using multivariate analyses adjusted for baseline factors. A subgroup analysis evaluated high-grade slip (≥4 mm).ResultsThe Slip group was older and had more kyphosis and worse baseline lordosis and JOA score. Fusion was performed more frequently in the Slip group, which also showed a greater reduction in cervical ROM at 2 years. Adjusted postoperative JOA score, JOACMEQ, and SF-36 outcomes were comparable between groups postoperatively. Within the Slip group, high-grade slip (≥4 mm) was associated with less JOA improvement in an exploratory subgroup analysis, whereas JOACMEQ and SF-36 scores were not influenced by slip severity.ConclusionsNeutral-radiograph-defined cervical anterolisthesis ≥2 mm was not independently associated with worse adjusted 2-year neurological, functional, or quality-of-life outcomes. High-grade slip (≥4 mm), however, may limit neurological recovery, underscoring the importance of evaluating segmental stability when substantial slippage is present.