Comparison of the Interlaminar and Transforaminal Approaches for Full-endoscopic Discectomy for the Treatment of L4/5 Lumbar Disc Herniation

This study aims to compare the outcomes of interlaminar and transforaminal approaches for full-endoscopic discectomy (FED) for treating L4/5 lumbar disc herniation (LDH). A retrospective study of patients with L4/5 LDH treated with interlaminar endoscopic lumbar discectomy (IELD, n = 19) or transforaminal endoscopic lumbar discectomy (TELD, n = 105) was conducted. Patient background, radiological findings, and operative data were collected. Oswestry Disability Index (ODI) and European Quality of Life-5 Dimension (EQ-5D) scores were recorded preoperatively and 1 and 2 years postoperatively. Although ODI and EQ-5D scores 1 and 2 years postoperatively improved statistically in the IELD and TELD groups, there were no statistical differences between the groups. IELD was predominantly performed in patients who were taller and heavier. The mean operative times and the frequency of laminectomy for IELD and TELD were 67.2 and 44.6 min and 63.2 and 17.1%, respectively (P < 0.001). The radiological findings showed that the concave configuration of the L4 lamina, interlaminar space width, and foraminal width were statistically different between the groups. There were no complications in either of the groups. Reoperation was required for recurrence in two and five patients in the IELD and TELD groups (P = 0.29), respectively. Operative outcomes were identical between the two groups. Although the operative time was longer in the IELD group, both approaches were safely and effectively performed. Depending on the patient's physique and preoperative radiological findings, the more suitable approach for L4/5 LDH should be chosen.