Clinical efficacy and precision of computer-assisted navigation combined with unilateral biportal endoscopy in lumbar spinal stenosis

The aim of this study was to assess the clinical efficacy, precision, and safety of computer-assisted navigation combined with unilateral biportal endoscopy (UBE) in the treatment of lumbar spinal stenosis (LSS). A retrospective analysis was conducted on the clinical data of 99 patients diagnosed with lumbar spinal stenosis who underwent UBE unilateral laminotomy for bilateral decompression at Yan’an University Affiliated Hospital between January 2023 and January 2025. Patients were allocated to a navigation group ( n = 48) or a conventional group ( n = 51) according to intraoperative use of a computer navigation system. The primary technical endpoint was bony resection volume measured on postoperative CT, and the primary clinical endpoint was ODI improvement at 7 days postoperatively. Secondary endpoints included skin-to-skin operative time, postoperative drainage volume, intraoperative fluoroscopy-session count, dural tear, facet resection angle, and VAS/ODI trajectories through 6 months. Navigation setup, reference-frame placement, 3D image acquisition, and registration were performed before skin incision and were not included in operative time. The navigation group had lower bony resection volume than the conventional group (1.2 ± 0.3 vs. 1.6 ± 0.4 cm³; mean difference, − 0.40 cm 3 ; 95% CI, − 0.54 to − 0.26; Cohen’s d = 1.13). For the ipsilateral facet resection angle (exploratory facet-trajectory surrogate), the absolute mean difference was − 1.9° (95% CI, − 2.69 to − 1.11), with values of 86.3 ± 1.7° in the navigation group and 88.2 ± 2.3° in the conventional group. This difference reflects measurable variation in resection trajectory at the imaging-measurement precision level and does not represent a proven structural or biomechanical benefit. The standardized effect size (Cohen’s d = 0.94) was large, driven by low within-group variance. After adjustment for age, BMI, baseline ODI, and Schizas grade, the difference in bony resection volume remained statistically significant (adjusted mean difference, − 0.38 cm 3 ; 95% CI, − 0.53 to − 0.23; p < 0.001). These imaging differences exceeded the respective minimum detectable changes; however, this facet-trajectory metric remains exploratory and has not been validated against actual percentage facet resection or residual facet width. Compared with conventional UBE-ULBD, computer-assisted navigation was associated with less bony resection and shorter skin-to-skin operative time in this retrospective cohort. The numerically lower dural-tear count was not statistically significant, and the study was underpowered for safety conclusions. Early postoperative recovery was statistically faster in the navigation group, although the ODI difference at 7 days did not reach the MCID threshold and outcomes were comparable at 3 and 6 months. These preliminary, hypothesis-generating findings require confirmation in adequately powered prospective studies with comprehensive radiation dosimetry and longer follow-up.