Risk Factor Analysis of Residual Low Back Pain After Unilateral Biportal Endoscopic Discectomy in Patients With Lumbar Disc Herniation

BACKGROUND Unilateral biportal endoscopy (UBE) is a novel surgical treatment for lumbar disc herniation (LDH). Some patients experience persistent residual low back pain (rLBP) after surgery. We aimed to identify risk factors for rLBP after UBE. MATERIAL AND METHODS This retrospective study analyzed 203 patients with LDH who underwent UBE in our department between January 2020 and August 2024. Inclusion criteria were a diagnosis of LDH treated by UBE and at least 1 year of follow-up. Exclusion criteria were severe spinal infection, previous spinal surgery, severe systemic disease, or incomplete follow-up data. Two groups were established based on visual analog scale scores at 1 year postoperatively: rLBP (score ≥3) and non-rLBP (score <3). Demographic characteristics, clinical outcomes, and imaging features were compared between groups. Logistic regression analyses were performed to identify rLBP risk factors. RESULTS There were 44 patients in the rLBP group (mean age, 52.59 years; ~43.2% women) and 159 patients in the non-rLBP group (mean age, 49.66 years; ~55.3% women). Postoperative rLBP was observed in 21.7% (44/203) of patients. Multivariate logistic regression analysis identified severe preoperative low back pain (P<0.001), high-grade facet joint osteoarthritis (FJOA) (P=0.005), and Modic type 1 changes (P=0.04) as independent risk factors for postoperative rLBP. CONCLUSIONS In patients with LDH, severe preoperative low back pain, high-grade FJOA, and Modic type 1 changes are predictive factors for rLBP after UBE. These parameters may be useful indicators for surgical decision-making and providing targeted treatment in high-risk populations.