Differences in Patient-Reported Outcomes Between Anterior and Posterior Approaches for Treatment of Cervical Spondylotic Myelopathy: A Quality Outcomes Database Analysis

Abstract

Objective Surgery for cervical spondylotic myelopathy (CSM) may use anterior or posterior approaches. Our objective was to compare baseline differences and validated postoperative patient-reported outcome measures between anterior and posterior approaches. Methods The NeuroPoint Quality Outcomes Database was queried retrospectively to identify patients with symptomatic CSM treated at 14 high-volume sites. Demographic, comorbidity, socioeconomic, and outcome measures were compared between treatment groups at baseline and 3 and 12 months postoperatively. Results Of the 1151 patients with CSM in the cervical registry, 791 (68.7%) underwent anterior surgery and 360 (31.3%) underwent posterior surgery. Significant baseline differences were observed in age, comorbidities, myelopathy severity, unemployment, and length of hospital stay. After adjusting for these differences, anterior surgery patients had significantly lower Neck Disability Index (NDI) and a higher proportion reaching a minimal clinically important difference (MCID) in NDI (p=0.005 at 3 months; p=0.003 at 12 months). Although modified Japanese Orthopaedic Association scores were lower in anterior surgery patients at 3 and 12 months (p<0.001 and p=0.022, respectively), no differences were seen in MCID or change from baseline. Greater EQ-5D improvement at 3 months after anterior vs. posterior surgery (p=0.024) was not sustained at 12 months and was insignificant on multivariate analysis. Conclusions In the largest analysis to date of CSM surgery data, significant baseline differences existed for patients undergoing anterior versus posterior surgery for CSM. After adjusting for these differences, patients undergoing anterior surgery were more likely to achieve clinically significant improvement in NDI at short- and long-term follow-up.