Comparative and qualitative analysis of endoscopic unilateral laminectomy with bilateral decompression versus interbody fusion in the treatment of grade 1 degenerative lumbar spondylolisthesis

OBJECTIVE Traditional management of symptomatic lumbar spondylolisthesis (SPL) involves interbody fusion (IBF). However, endoscopic unilateral laminectomy with bilateral decompression (E-ULBD) has emerged as a less invasive alternative with growing evidence of effectiveness. The authors aimed to comprehensively compare outcomes between E-ULBD and IBF in grade 1 lumbar degenerative SPL. METHODS The data of patients who underwent E-ULBD or IBF for symptomatic lumbar SPL by a single surgeon during the same period were retrospectively reviewed. Demographics, SPL characteristics, surgical profiles, pain management, patient-reported outcomes, and surgical/medical complications were analyzed. Surgical complications were classified by location (index vs adjacent level) and analyzed separately from uncomplicated cases. RESULTS Eighty-one patients (51 E-ULBD, 30 IBF) were included with a mean follow-up of 43.8 months. E-ULBD demonstrated significantly shorter hospitalization, less blood loss, and fewer medical complications. Index-level surgical complications were comparable (35.3% E-ULBD, 16.7% IBF; p = 0.072), whereas IBF had significantly more adjacent-level complications (20.0% vs 3.9%, p = 0.046), resulting in worse pain and Oswestry Disability Index scores at the final follow-up. In the E-ULBD group, segmental instability and facet violation > 10% were significantly associated with symptomatic SPL progression. CONCLUSIONS For grade 1 lumbar SPL, E-ULBD may provide superior recovery profiles and less clinical burden from complications compared with IBF. Nevertheless, both procedures were associated with surgical complication rates approaching 40%, whereas 60% of uncomplicated cases achieved comparable favorable outcomes. Facet violation > 10% was a significant risk factor for symptomatic SPL progression following E-ULBD.