Publication:

Unilateral biportal endoscopy for lumbar spinal stenosis: outcomes and potential to reduce fusion in Schizas grade D patients

Background Unilateral biportal endoscopy (UBE) is an established minimally invasive technique for the surgical management of lumbar spinal stenosis (LSS). However, prospective evidence regarding its effectiveness in severe stenosis, particularly Schizas Grade D disease, remains limited. This study evaluated the clinical and radiological outcomes of UBE with unilateral laminotomy for bilateral decompression in patients with LSS, with particular emphasis on severe stenosis.

Methods This prospective single-surgeon study included 134 consecutive patients with LSS who underwent UBE decompression between April 2021 and September 2023. Patients with pre-existing instability or other indications for fusion were excluded. Clinical outcomes were assessed using the Visual Analog Scale (VAS) for back and leg pain and the Oswestry Disability Index (ODI) at a minimum follow-up of 12 months. Particular attention was paid to the outcomes of patients with Schizas Grade D stenosis.

Results Of the 134 patients, 128 completed the 12-month follow-up. Mean VAS leg pain improved from 7.92 to 0.63 (p<0.001), while mean ODI improved from 69.66 to 39.34 (p<0.001). Among the 42 patients with Schizas Grade D stenosis, two patients (4.8%) required revision surgery, with one patient (2.4%) subsequently undergoing instrumented fusion. Two dural tears (4.8%) occurred in this subgroup. No patient developed postoperative instability requiring unplanned fusion during the follow-up period.

Conclusions UBE provides safe and effective decompression for carefully selected patients with lumbar spinal stenosis, including severe Schizas Grade D disease, resulting in significant pain relief and functional improvement. The low revision and subsequent fusion rates observed in this series suggest that motion-preserving decompression may be a viable treatment strategy for selected stable spines, although larger comparative studies with longer follow-up are required.