Risk factors for recurrent lumbar disc herniation after percutaneous endoscopic lumbar discectomy: the role of spinopelvic parameters and facet joint degeneration

BACKGROUND: Recurrent lumbar disc herniation (rLDH) remains a major cause of treatment failure after percutaneous endoscopic lumbar discectomy (PELD). The roles of spinopelvic parameters and facet joint degeneration in postoperative recurrence have not been fully clarified. OBJECTIVE: To investigate the associations between spinopelvic parameters, facet joint degeneration, and recurrent lumbar disc herniation after PELD. METHODS: A total of 106 patients who underwent single-level PELD were retrospectively analyzed, including 53 patients with recurrence (rLDH group) and 53 without recurrence (non-rLDH group). Propensity score matching was performed to balance baseline characteristics. Clinical and radiological parameters, including pelvic incidence (PI), lumbar lordosis (LL), PI-LL mismatch, disc height (DH), range of motion (ROM), facet joint degeneration, Pfirrmann grade, and Modic changes, were evaluated. Multivariate logistic regression and receiver operating characteristic (ROC) curve analyses were conducted. RESULTS: After matching, no significant differences were observed in age, sex, BMI, or surgical level between the two groups (all P > 0.05). The rLDH group exhibited significantly greater PI-LL mismatch, DH, ROM, facet degeneration, Pfirrmann grade, and a higher prevalence of Modic changes (all P < 0.05). Multivariate analysis identified DH (OR = 1.50, 95% CI: 1.14-1.97), facet degeneration (OR = 6.00, 95% CI: 1.74-20.70), Modic changes (OR = 7.35, 95% CI: 1.55-34.86), PI-LL mismatch (OR = 1.08, 95% CI: 1.01-1.14) as independent predictors of recurrence. ROC analysis showed that DH (AUC = 0.785) and ROM (AUC = 0.749) had the highest predictive value. CONCLUSIONS: PI-LL mismatch, facet joint degeneration, disc height, and Modic changes are independent risk factors for recurrent lumbar disc herniation after percutaneous endoscopic lumbar discectomy. PI-LL mismatch greater than 10° and facet joint degeneration (Weishaupt grade ≥ 2) are significantly associated with an increased risk of recurrence.