Radiological decompression and clinical outcomes following endoscopic unilateral biportal lumbar interbody fusion vs. conventional posterior lumbar interbody fusion

Objective To compare the clinical, perioperative, and radiological outcomes of endoscopic unilateral biportal endoscopic lumbar interbody fusion (ULIF) and conventional posterior lumbar interbody fusion (PLIF) for single-level degenerative lumbar disease. Methods This retrospective study included 67 patients undergoing lumbar interbody fusion (ULIF, n = 29; PLIF, n = 38). Perioperative outcomes included operative time, blood loss, and hospital stay. Clinical outcomes were assessed using the visual analogue scale (VAS) and Oswestry Disability Index (ODI). Radiological outcomes included changes in spinal canal cross-sectional area (CSA), canal diameter, and fusion status. Results Operative time was longer in the ULIF group than in the PLIF group (226.5 ± 50.6 vs. 184.1 ± 57.4 min, p = 0.002). However, ULIF resulted in less blood loss (87.6 ± 56.7 vs. 251.2 ± 198.0 mL, p < 0.001), shorter total hospital stay (11.7 ± 4.0 vs. 14.6 ± 4.6 days, p = 0.008), and shorter postoperative hospital stay (4.1 ± 1.0 vs. 8.5 ± 1.4 days, p < 0.001). VAS improvements were comparable between the two surgical approaches. Although PLIF showed a greater reduction in ODI from baseline, absolute ODI values at 12 months were similar. Conclusions ULIF was associated with less intraoperative blood loss and shorter postoperative hospitalization while achieving similar 12-month pain outcomes and fusion rates to PLIF in this cohort. No statistically significant between-group differences were detected in postoperative complications. The modest radiological differences observed with ULIF should be interpreted cautiously, and the small observational cohort was not powered to establish equivalence or comparable safety between the two procedures. Larger prospective studies with longer follow-up are warranted.