Association of preoperative Pfirrmann grade with 12-month outcomes after interlaminar full-endoscopic lumbar discectomy with successful annular suture repair: a single-center retrospective cohort study

Background Whether advanced disc degeneration affects outcomes after annular suture repair remains uncertain. This study evaluated the association of Pfirrmann grade IV with 12-month outcomes and MRI-confirmed symptomatic recurrence among selected patients undergoing interlaminar full-endoscopic lumbar discectomy with successful annular suture repair. Methods This single-center retrospective cohort included 226 patients treated between May 2023 and March 2025. Patients were classified as Pfirrmann grades I–III ( n = 151) or grade IV ( n = 75). The primary estimands were ATT-IPTW-adjusted between-group differences in VAS-back, VAS-leg, and ODI at 12 months. Weighted generalized estimating equations assessed longitudinal trajectories. Modified MacNab outcomes and MRI-confirmed symptomatic recurrence were secondary outcomes; postoperative MRI was symptom-triggered. Results At 12 months, adjusted grade IV-minus-grades I–III differences were 0.070 for VAS-back (95% CI, −0.270–0.409), −0.005 for VAS-leg (95% CI, −0.334–0.325), and 0.297 for ODI (95% CI, −1.180–1.774). Results were consistent in propensity-score-matched, grades III–IV restricted, and ordinal sensitivity analyses. Excellent/good modified MacNab outcomes occurred in 93.4% and 92.0% of patients, respectively. MRI-confirmed symptomatic recurrence occurred in 6/151 and 2/75 patients. Recurrence analyses were exploratory because only eight events occurred. Conclusions Among selected patients with successful annular suture repair, Pfirrmann grade IV was not associated with a clinically important disadvantage in 12-month pain or functional outcomes. No increased recurrence signal was observed, but the study cannot determine whether Pfirrmann grade affects surgical candidacy, repairability, or successful closure.