A Prospective Comparative Study of UBE-ULBD Versus Endo-ULBD for Lumbar Spinal Stenosis

Prospective, randomized controlled trial (RCT). To directly compare the clinical and radiologic outcomes of unilateral biportal endoscopic unilateral laminotomy for bilateral decompression (UBE-ULBD) versus single-port endoscopic unilateral laminectomy for bilateral decompression (Endo-ULBD) for single-level lumbar spinal stenosis (LSS). While UBE-ULBD has emerged as an efficacious minimally invasive technique for degenerative LSS, the comparative efficacy and safety profile of Endo-ULBD remains comparatively underexplored. This study aims to bridge this knowledge gap by directly comparing these two endoscopic modalities. One hundred ten patients with Schizas grade C/D LSS were randomized to UBE-ULBD or Endo-ULBD (55/group). Primary outcomes included VAS, ODI, and modified Macnab criteria. Radiologic outcomes focused on dural sac cross-sectional area (DSCSA) and facet preservation. All procedures were performed by the same senior surgeon. Analysis was conducted per ITT and PP principles, with a 12-month follow-up. Both groups demonstrated significant clinical improvement ( P <0.05). UBE-ULBD was associated with a shorter operative time ( P <0.01), largely attributable to the ergonomic advantages of the dual-portal system and the use of a high-speed drill. Notably, a trephine was utilized exclusively in the Endo-ULBD group. Conversely, Endo-ULBD was associated with a shorter postoperative hospital stay ( P <0.01), a difference potentially influenced by both technical and nonclinical factors. Radiologic outcomes, including dural sac expansion and facet joint preservation rates, were comparable between groups ( P >0.05). No significant intergroup differences were observed in VAS, ODI, or modified Macnab satisfaction rates at the 12-month follow-up (ITT: 90.9% in UBE-ULBD vs . 89.1% in Endo-ULBD, P =0.92; PP: 98.0% in UBE-ULBD vs . 94.0% in Endo-ULBD, P =0.92). One dural tear occurred in the Endo-ULBD cohort. Both UBE-ULBD and Endo-ULBD proved safe and effective, yielding comparable clinical and radiologic outcomes at the 12-month follow-up. Within the constraints of this study, both techniques represent viable options for minimally invasive decompression.