Surgical treatment outcomes in cervical spondylotic myelopathy: a retrospective analysis of 32 patients and evaluation of prognostic factors

Aims: This study aimed to evaluate the clinical and radiological outcomes of patients who underwent surgical treatment for cervical spondylotic myelopathy (CSM) and to identify prognostic factors. Methods: Thirty-two patients who underwent surgical treatment for CSM at our clinic between 2019 and 2024 were retrospectively analyzed. Demographic characteristics, preoperative and postoperative modified Japanese Orthopaedic Association (mJOA) scores, Nurick scores, radiological parameters, and complications were recorded. Radiological measurements were performed by two independent observers, with excellent inter-observer reliability (ICC=0.92 for compression ratio, ICC=0.89 for Cobb angle). The effects of T2 hyperintensity severity, presence of OPLL (Ossification of the Posterior Longitudinal Ligament), age, compression ratio, and number of compression levels on surgical outcomes were analyzed using correlation analysis, comparative tests, and multivariate linear regression. The median follow-up period was 6.0 months (IQR: 3.0-12.0 months; range: 1-48 months). Results: Of the 32 patients included in the study, 27 (84.4%) were male and 5 (15.6%) were female. The mean age was 57.6±9.2 years (range: 42-73 years). The mean preoperative mJOA score was 9.78±4.02, which increased to 15.44±2.90 postoperatively (p<0.001). The mean neurological recovery rate calculated using the Hirabayashi formula (27) was 73.0±22.2%. Nurick scores significantly improved from 3.00±1.30 preoperatively to 0.91±1.20 postoperatively (p<0.001). Marked T2-weighted Magnetic Resonance Imaging (MRI) hyperintensity was detected in 71.9% of patients. OPLL was present in 40.6% of patients. The mean preoperative spinal cord compression ratio was 47.0±10.9%. Correlation analysis revealed a significant positive correlation between preoperative mJOA score and recovery rate (r=0.551, p=0.001). Multivariate linear regression analysis confirmed that preoperative mJOA score was the only independent predictor of recovery rate (β=0.551, p=0.001), while T2 hyperintensity severity (p=0.513), presence of OPLL (p=0.079), age (p=0.984), compression ratio (p=0.645), and number of levels (p=0.631) did not show significant independent associations. Post-hoc power analysis revealed that the study had 80% power to detect large effect sizes (Cohen’s d ≥0.90) but was underpowered for moderate effects. Only one patient (3.1%) developed pulmonary embolism as a complication. Conclusion: Surgical treatment in CSM provides significant improvement in mJOA and Nurick scores with a low complication rate. Preoperative mJOA score is the most important prognostic factor and emphasizes the importance of early surgical intervention. In this patient cohort, marked T2 hyperintensity, presence of OPLL, high compression ratio, advanced age, and multilevel involvement did not show significant associations with surgical outcomes, though the limited sample size may have precluded detection of moderate effects. These findings suggest that satisfactory functional outcomes can be achieved across a diverse patient population, though larger studies are needed to definitively establish the role of these factors.