Functional recovery after laminoplasty versus staged anterior-posterior fusion for multilevel cervical ossification of the posterior longitudinal ligament

Abstract

Background: Ossification of the posterior longitudinal ligament (OPLL) causes progressive narrowing of the cervical canal and neurological deficits. Cervical laminoplasty (LP) and staged anterior-posterior fusion (APF) are widely used, but their comparative outcomes remain controversial. This study compared clinical and radiographic outcomes of LP and APF for multilevel OPLL, with analysis according to OPLL subtype. Methods: We retrospectively reviewed 217 patients with cervical OPLL who underwent LP (n = 135) or APF (n = 82) between 2014 and 2023. All patients had >= 3 operated levels and >= 1-year follow-up. Clinical outcomes included Japanese Orthopaedic Association (JOA) score, Neck Disability Index (NDI), visual analog scale (VAS) for pain, and subjective improvement rate (IR). Radiographic outcomes included C2-7 lordosis and sagittal vertical axis (SVA). Assessments were performed preoperatively and at 6 months, 1 year, and 2 years. Between-group comparisons and longitudinal analyses were performed using t-tests, chi-square tests, and repeated-measures ANOVA. Results: Baseline characteristics were comparable between groups. Both LP and APF significantly improved neck and arm pain and JOA scores, with no group difference at 2 years. APF achieved greater correction of sagittal alignment, with larger improvements in C2-7 lordosis across all OPLL types (p < 0.001). However, APF patients had consistently higher NDI scores during early follow-up (p < 0.001), particularly in domains requiring cervical motion (personal care, lifting, work, driving). Subgroup analysis showed that patients with segmental-type OPLL experienced the greatest postoperative disability after fusion due to higher preoperative motion. These differences gradually decreased by 2 years, indicating functional adaptation. Although the difference did not reach statistical significance (p = 0.0719), there was a trend toward higher IR in the APF group. Conclusion: Both LP and APF provided significant neurological recovery and pain relief in multilevel OPLL. APF yielded superior sagittal alignment but was associated with higher early postoperative disability, most pronounced in segmental-type OPLL. Differences diminished by the second postoperative year, suggesting patient adaptation. Surgical decision-making should consider OPLL subtype, preoperative mobility, and the trade-off between motion preservation and alignment correction.