Abstract
OBJECTIVE: This study aimed to evaluate the clinical and radiological outcomes of unilateral laminotomy for bilateral decompression (ULBD) using biportal endoscopic spinal surgery (BESS) in patients with central canal stenosis, with and without low-grade degenerative lumbar spondylolisthesis (DLS). METHODS: A retrospective observational study was conducted on 170 patients who underwent BESS-ULBD between 2015 and 2018, with at least 2 years of follow-up. Patients were categorized into 2 groups: group A (68 patients) with central stenosis and low-grade DLS and group B (102 patients) with central stenosis alone. Clinical outcomes were assessed using the visual analogue scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), and Modified MacNab criteria. Radiological assessments included sagittal translation measurements on dynamic flexion-extension radiographs. RESULTS: Both groups significantly improved clinical outcomes at the final follow-up (p<0.05). Group A's mean VAS scores improved from 3.8±2.4 to 1.9±2.0 for back pain and from 6.4±1.8 to 2.3±2.0 for leg pain. In group B, back pain improved from 3.9±2.5 to 1.7±1.9, and leg pain from 6.6±2.0 to 2.2±2.2. ODI scores also improved significantly in both groups. Radiological evaluation showed no significant changes in sagittal translation postoperatively, indicating preserved spinal stability. Both groups had comparable clinical outcomes, with no major complications reported. CONCLUSION: BESS-ULBD is a safe and effective minimally invasive option for managing central canal stenosis, with or without low-grade DLS. This technique provides substantial symptom relief, preserves spinal stability, and presents a promising alternative to more invasive fusion procedures in carefully selected patients.