Learning curve in full-endoscopic lumbar surgery for disc herniation in a spine clinic in Mexico: Comparative analysis of IELD and TELD techniques

Introduction: Lumbar disc herniation (LDH) is a common condition that can be treated with full-endoscopic surgery (FES). Publications suggest that the learning curve is steep. There are no reports from Latin America. Objective: To evaluate the learning curve for FES in LDH and compare outcomes between full-endoscopic interlaminar approach (IELD) and full-endoscopic transforaminal approach (TELD) in Mexico. Methods: A retrospective cohort of 114 consecutive patients (68 IELD, 46 TELD) was analyzed. Learning curves were modeled using segmented linear regression and Cumulative Sum (CUSUM) analysis to identify transition points in operative time. Clinical outcomes were assessed using the Visual Analog Scale (VAS) for leg/back pain and the Oswestry Disability Index (ODI) at 12 months follow-up. Ridge-penalized logistic regression was used to identify predictors of prolonged surgery. Results: Technique-specific breakpoints were observed at case 18 for IELD and case 20 for TELD, while the overall learning curve was at 44 cases. The median operative time significantly decreased from the early to late phase (IELD: 120 to 60 min; TELD: 90 to 60 min). Clinical success (≥30% improvement) was achieved by over 76% of patients across all metrics. There were no significant differences in complication and conversion rates between the learning phases. Discussion & conclusions: Proficiency in FES for LDH was reached after approximately 20 cases per technique. Surgeon experience may influence this learning curve. Both methods yield excellent clinical outcomes. FES is effective, safe, and reproducible in Latin America.