Transforaminal vs interlaminar full -endoscopic lumbar discectomy at the L4/L5 level: a systematic review and meta -analysis

INTRODUCTION: Full-endoscopic lumbar discectomy (ELD) can be performed using either the transforaminal (TELD) or interlaminar (IELD) approach. Although both techniques are widely used, the optimal approach for the L4/L5 level remains debated. No previous meta-analysis has specifically compared TELD and IELD exclusively for single-level L4/L5 lumbar disc herniation (LDH). AIM: We aimed to compare clinical and perioperative outcomes of TELD vs IELD for single-level L4/L5 LDH. MATERIALS AND METHODS: A systematic review and meta-analysis were conducted according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, Embase, Scopus, and Web of Science databases were searched through November 2025. Comparative studies reporting outcomes for TELD and IELD specifically at the L4/L5 level were included. Continuous variables were analyzed using mean differences (MDs), whereas risk ratios (RRs) under a random-effects model were used to analyze binary outcomes. RESULTS: Three comparative studies including 260 patients undergoing TELD (n = 189) and IELD (n = 71) met the inclusion criteria. Clinical outcomes were comparable between the techniques. Pooled analysis showed no clinically relevant difference in postoperative Visual Analog Scale leg pain (MD, 0.32; 95% CI, 0–0.63) or Oswestry Disability Index (MD, 1.94; 95% CI, 0.94–2.94). Operative time tended to be shorter with TELD, but the difference was not significant (MD, −12.6 min; 95% CI, −34.6 to 9.4). Length of hospital stay (LOS) was identical between the groups (MD, 0.007 d). Complication (RR, 1.48; 95% CI, 0.23–9.7) and reoperation rates (RR, 0.96; 95% CI, 0.21–4.4) were also similar between the cohorts. CONCLUSIONS: TELD and IELD provide equally effective and safe treatment for single-level L4/L5 LDH. Clinical outcomes, LOS, as well as complication and reoperation rates were equivalent. Operative time showed substantial heterogeneity across the studies, precluding a definitive conclusion regarding time efficiency. The choice of approach should be based on patient anatomy, herniation morphology, and surgeon expertise rather than expected differences in technique efficacy.