Radiologic and Clinical Predictors of Reoperation Following Unilateral Biportal Endoscopic Spine Surgery: A Retrospective Cohort Study

Abstract

Purpose Unilateral biportal endoscopic discectomy (UBE) is an effective and minimally invasive technique for the treatment of degenerative lumbar diseases. However, reoperation may be required, and evidence on how risk factors vary according to the timing of reoperation remains limited. This study aimed to identify the clinical and radiologic factors associated with short-term (<6 months) and long-term (>= 6 months) reoperations following UBE. Materials and Methods This retrospective study included 80 patients who underwent reoperation after UBE between January 2016 and December 2023 with a minimum 24-month follow-up. The patients were classified into short-term and long-term reoperation groups. Clinical and radiologic parameters, including disc degeneration grade, facet joint osteoarthritis grade, and comorbidities, were compared between groups. Multivariable logistic regression was used to evaluate preoperative factors predicting postoperative functional improvement. Results Reoperations were performed for incomplete decompression (27.5%), facet cysts (10.0%), recurrent herniation (8.8%), restenosis (8.0%), and postoperative instability (43.7%). Long-term reoperation was associated with greater disc degeneration, a higher grade of facet joint osteoarthritis, and a higher prevalence of diabetes mellitus (DM). Short-term reoperation was mainly due to inadequate decompression, whereas long-term reoperation was largely attributable to postoperative instability. Multivariable analysis identified a higher preoperative grade of facet joint osteoarthritis as a predictor of postoperative functional improvement. Conclusion Short-term reoperation after UBE is primarily related to inadequate decompression, whereas long-term reoperation is linked to advanced disc degeneration, severe facet joint osteoarthritis, postoperative instability, and DM. These findings highlight the importance of thorough preoperative assessment of facet arthropathy and disc degeneration, ensuring adequate initial decompression, and careful postoperative management, particularly in patients with DM.