Clinical efficacy and sagittal alignment restoration of unilateral biportal endoscopic-assisted anterior cervical discectomy and fusion for cervical spondylosis: a retrospective comparative study

Anterior cervical discectomy and fusion (ACDF) remains the established operative approach for managing cervical spondylosis (CS). However, traditional open ACDF involves considerable damage to the surrounding soft tissues and relatively slow postoperative recovery. The emergence of Unilateral Biportal Endoscopy (UBE)-assisted ACDF (UBE-ACDF) offers a novel approach that combines effective decompression with the advantages of a minimally invasive procedure. Nevertheless, clinical evidence comparing UBE- ACDF with traditional ACDF remains scarce, and its clinical efficacy requires further evaluation. To compare and evaluate the perioperative outcomes, clinical functional recovery, and imaging differences between UBE-ACDF and traditional ACDF in the treatment of CS. 84 cases diagnosed with CS were divided into the UBE-ACDF group ( n = 32) and the ACDF group ( n = 52). The perioperative efficacy (operation time, incision length, visible/hidden blood loss, hospitalization cost), clinical outcomes at multiple follow-up time points (VAS, NDI, and JOA), imaging outcome (sagittal balance index, segmental Cobb Angle and disc height) and complications were systematically compared between the two groups. The two groups were well-matched in terms of baseline demographic and clinical characteristics. Compared with the ACDF group, the UBE-ACDF group showed significant minimally invasive advantages in the perioperative period such as shorter hospital stay ( P = 0.039), and lower intraoperative visible blood loss (143.97 vs. 375.81 mL, P < 0.001). The clinical function was significantly improved in both groups. The final follow-up VAS-arm score was significantly higher in the UBE-ACDF group than in the ACDF group, indicating greater long-term arm pain relief in the conventional ACDF group ( P = 0.005). Intervertebral height restoration was greater in the UBE-ACDF group. However, the interpretation of T1 slope changes was limited by significant baseline differences between groups. UBE-ACDF may represent a feasible minimally invasive alternative to conventional ACDF for selected patients with CS. It provides comparable overall neurological and functional recovery while reducing perioperative surgical trauma. However, conventional ACDF showed better long-term arm pain relief at the final follow-up, and T1 slope findings should be interpreted cautiously because of baseline sagittal alignment imbalance. Larger prospective studies with longer follow-up are required to confirm fusion-related outcomes and long-term radiographic durability.