Endoscopic discectomy for L4-L5 disc herniation: A meta-analysis comparing transforaminal and interlaminar approaches

Background: Lumbar disc herniation can be debilitating. Percutaneous endoscopic discectomy (PED) is an emerging minimally invasive alternative to microdiscectomy, performed through either an interlaminar (IL) or transforaminal (TF) approach. Research question: There is existing evidence comparing these two approaches for managing the most common herniation level, L4-L5, but it lacks consistency and clear conclusions. Therefore, a meta-analysis is necessary to determine if one approach is superior to the other. Methods: Medline, Cochrane, and Google Scholar (pages 1-20) were searched until August 1, 2025, following PRISMA guidelines. The data extracted included overall complications, reoperation rates, operative time, length of stay (LOS), and improvements in patient-reported outcome measures (PROMs) at least one year after surgery. Results: Six studies involving 456 patients (276 TF; 180 IL) were included. No significant differences were found between the two approaches regarding overall complications (OR = 1.81; 95 % CI: 0.51-6.44; p = 0.36), reoperation rates (OR = 2.10; 95 % CI: 0.38-11.70; p = 0.40), operative time (MD = 0.73; 95 % CI: -14.83-16.29; p = 0.93), or LOS (MD = 0.03; 95 % CI: -0.13-0.19; p = 0.69). Similarly, improvements in ODI (MD = -1.06; 95 % CI: -2.63-0.52; p = 0.19), back pain (MD = 0.29; 95 % CI: -0.61-1.19; p = 0.53), and leg pain (MD = -0.44; 95 % CI: -1.19-0.31; p = 0.25) showed no significant differences. Discussion and conclusion: Both approaches produce similar results regarding overall complications, reoperation rates, operative time, LOS, and PROMs. The choice of approach should thus be based on surgeon experience, patient-specific anatomy, and resource availability.