C2-Involving Cervical Ossification of the Posterior Longitudinal Ligament (OPLL): Dome-like Laminoplasty Versus Laminectomy With Fusion

Study DesignRetrospective cohort study.ObjectivesTo compare the outcomes of C2 dome-like laminoplasty (C2-Dom LP) and C2 laminectomy with fusion (C2-LF) in patients with C2-involving ossification of the posterior longitudinal ligament (OPLL) and to identify radiological predictors that guide optimal surgical selection.MethodsA retrospective analysis of 143 patients (C2-Dom LP, 71; C2-LF, 72) was performed. Radiological evaluations were C2 cross-sectional area (CSA), cervical range of motion (ROM), canal-occupying ratio, and sagittal alignment parameters. Clinical outcomes were assessed using Japanese Orthopedic Association (JOA) scores, neck disability index, and visual analog scale. Subgroup analysis was conducted according to canal compromise severity. A propensity-matched analysis using demographic and perioperative variables was performed to ensure an unbiased comparison.ResultsAfter propensity-matched analysis, C2-Dom LP preserved cervical ROM and sagittal alignment, whereas C2-LF produced substantially greater canal expansion. Both groups demonstrated clinical improvement, but C2-LF achieved a significantly higher JOA recovery rate following matching, highlighting its superior neurological benefit. In the high-compromise subgroup, defined by a CSA cutoff of 92.24 mm², C2-LF yielded markedly better neurological recovery than C2-Dom LP. Logistic regression identified smaller CSA, larger sagittal vertical axis, and lower baseline JOA score as independent predictors of poorer outcome.ConclusionsC2-Dom LP preserved motion and alignment and can be effective for standard-risk patients. C2-LF achieved greater canal expansion and better recovery in high-compromise patients. A CSA-based, risk-stratified approach could improve with adoption of this threshold, potentially enhancing surgical decision-making and the long-term outcomes of patients with C2 involvement OPLL.