Effect of K-line (-) or (+) on surgical outcomes in cervical ossification of the posterior longitudinal ligament: A systematic and meta-analysis.

BackgroundTo conduct a systematic review and meta-analysis assessing the influence of K-line status on postoperative clinical outcomes in patients with cervical posterior longitudinal ligament ossification (OPLL).MethodsWe searched PubMed, Embase, OVID, Cochrane Library, and Web of Science databases for English-language literature related to K-line and OPLL up to June 7, 2024. The study underwent rigorous selection, quality assessment, and data extraction, followed by meta-analysis using Review Manager 5.3 and Stata 17.0 software. This study has been registered with the international PROSPERO registry (registration number: CRD42024558578).ResultsSeventeen articles encompassing 1247 patients were included. The meta-analysis revealed that patients with a positive K-line (K-line (+)) exhibited significantly enhanced Japanese Orthopaedic Association score recovery rate (mean differences [MD] = 19.28, 95% confidence interval [CI]: 12.28-26.28, P ConclusionA positive preoperative K-line (K-line (+)) is a better predictor of prognosis and is associated with improved clinical outcomes in patients with multi-segmental cervical OPLL compared to a negative K-line (K-line (-)).