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

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.

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.

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.

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.

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.