Transforaminal Endoscopic Lumbar Discectomy Versus Interlaminar Endoscopic Lumbar Discectomy for Lumbar Disc Herniation: A Systematic Review of Clinical Outcomes, Quality of Life, and Surgical Selection Strategies.

Background: Transforaminal endoscopic lumbar discectomy (TELD) and interlaminar endoscopic lumbar discectomy (IELD) have emerged as primary minimally invasive treatments for lumbar disc herniation (LDH). However, comparative data regarding long-term quality of life (QoL) and specific patient-selection criteria remain fragmented. Objective: This systematic review aims to compare the clinical outcomes, complications, and QoL metrics of TELD versus IELD to establish evidence-based surgical selection strategies. Methods: Following the Preferred Reporting Items for Systematic Reviews guidelines, a systematic search was conducted in PubMed, Embase, Cochrane Library, and Web of Science for the period 2000-2025. We included randomized controlled trials and high-quality cohort studies with a minimum of 20 patients. Data from 31 high-quality studies involving 5,873 patients were reviewed and summarized narratively Registration: Not prospectively registered (PROSPERO). Results: Both TELD and IELD showed superior results compared to open discectomy. Most studies reported comparable clinical outcomes between TELD and IELD, with some evidence suggesting marginal advantages for TELD in functional recovery scores. Complication rates were observed to be lower for endoscopic techniques compared to open surgery. Economic analyses across the reviewed literature indicated that both TELD and IELD are cost-effective, with values generally falling between Conclusion: TELD and IELD are highly effective for LDH. While clinical outcomes are similar, TELD offers marginal advantages in functional recovery, whereas IELD is preferred for L5-S1 herniations. Selection should be tailored to the herniation level and the surgeon's expertise.