Comparison of Anterior and Posterior Surgical Approaches for Cervical Ossification of the Posterior Longitudinal Ligament Stratified by Spinal Levels: A Systematic Review and Meta-Analysis

OBJECTIVE: To compare the outcomes of anterior and posterior surgical approaches for treating cervical ossification of the posterior longitudinal ligament across multiple spinal levels, including 1-2 spinal levels, ≥ 3 levels, or studies that operated on both spinal levels, called mixed spinal levels. METHODS: A search strategy using pertinent keywords was employed in the MEDLINE, Embase, Scopus, and Web of Science databases. Data on Modified Japanese Orthopaedic Association (mJOA) scores, radiographic outcomes, and complications were extracted. A random-effects meta-analysis, subgroup meta-analysis, and sensitivity analysis were performed. RESULTS: Among 13 included studies, the anterior approach was statistically associated with improved C2-C7 Cobb angle, mJOA scores between 6 and 12 months, and mJOA recovery rates at more than 12 months (mean difference: 5.87°, 0.49°, and 18.81°, respectively). Conversely, the laminoplasty (LAMP) approach was more effective at maintaining the range of motion in patients with ≥ 3 spinal levels operated on (mean difference: -1.78°). The odds ratio (OR) of C5 palsy revealed lower odds in anterior approaches following surgery at ≥ 3 spinal levels (OR: 0.24, 95% confidence interval: 0.15 to 0.37). The odds of dysphagia following surgery at mixed spinal levels were higher in anterior approaches (OR: 3.68, 95% confidence interval: 1.24 to 10.94). CONCLUSIONS: LAMP significantly preserved cervical range of motion. LAMP and laminectomy with fusion reduced dysphagia but increased C5 palsy. The anterior approach improved alignment and function, but the mJOA score and recovery rate were not clinically meaningful. Patient-specific characteristics should be taken into account when selecting the surgical approach.