Anterior vs. posterior approaches in the management of multilevel degenerative cervical myelopathy: a systematic review and meta-analysis

BACKGROUND CONTEXT: Degenerative cervical myelopathy (DCM) is the commonest cause of spinal cord dysfunction. The optimal surgical approach for multilevel DCM (MDCM) remains debated. PURPOSE: To assess functional, patient-reported, and surgical-related outcomes of anterior and posterior surgical approaches for MDCM. STUDY DESIGN: Systematic review and meta-analysis. OUTCOME MEASURES: Primary outcomes included modified Japanese Orthopaedic Association (mJOA), Neck Disability Index (NDI), pain visual analogue scale (VAS), SF-36, and EQ-5D at ≥1-year. Secondary outcomes included length of stay, C5 palsy, reoperation and intraoperative bleeding. METHODS: Following the PRISMA guidelines, MEDLINE, Web of Science, and Cochrane databases (inception to November 2024) were accessed to search for studies comparing anterior and posterior approaches in adult patients with MDCM spanning ≥2 levels, including cervical spondylotic myelopathy (CSM) and ossification of the posterior longitudinal ligament (OPLL). Meta-extraction was performed independently by multiple reviewers using Covidence. Data were pooled by a random-effects model, with effect sizes reported as mean differences (MDs) and odds ratios (ORs). Mixed-effects meta-regression accounted for baseline variability. Subgroup analyses examined CSM vs OPLL and follow-up duration (1 vs ≥2 years). RESULTS: At final follow-up, the anterior approach demonstrated significantly better mJOA (MD 0.42, 95% CI, 0.20 to 0.64), NDI (MD -1.29, -2.41 to -0.17) and VAS (MD -0.60, -1.04 to -0.17), though did not reach minimal clinically important differences (MCIDs). Quality-of-life measures were comparable. Subgroup analysis further supported anterior surgery across CSM and OPLL groups. Early advantages of anterior surgery in NDI and VAS diminished until becoming nonsignificant at ≥2 years. Anterior surgery resulted in shorter length of stay (LOS) (MD -1.41 days, -1.91 to -0.90) and lower odds of C5 palsy (OR 0.37, 0.28-0.49). CONCLUSIONS: Both surgical approaches yield comparable long-term outcomes, with anterior surgery demonstrating statistically significant early functional advantages, shorter LOS, and lower odds of C5 palsy. However, these advantages diminish over time, with functional improvements not consistently reaching MCIDs. Given the heterogeneity of DCM, surgical decision-making should be individualized, incorporating patient-specific factors and long-term functional priorities to optimize outcomes.