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

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• Picked for Orthopedics and Sports Medicine (top studies of the week, 13 September 2026): Prospective RCT comparing UBE‑ULBD vs Endo‑ULBD for lumbar stenosis

Abstract

STUDY DESIGN: Prospective, randomized controlled trial (RCT). OBJECTIVE: To directly compare the clinical and radiological 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). SUMMARY OF BACKGROUND DATA: 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. METHODS: 110 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. Radiological 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. RESULTS: 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 non-clinical factors. Radiological 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. CONCLUSIONS: Both UBE-ULBD and Endo-ULBD proved safe and effective, yielding comparable clinical and radiological outcomes at the 12-month follow-up. Within the constraints of this study, both techniques represent viable options for minimally invasive decompression.

Abstract as published, via PubMed.