Assessment of Proximal Facet Joint Violations in Robotic and Augmented Reality-Assisted Pedicle Screw Placement

Study Design: Single-center retrospective cohort study. Objective: The primary objective was to evaluate the incidence of proximal facet joint violation (FJV) in lumbar and sacral pedicle screw placement, comparing robotic-assisted navigation (RAN) versus augmented reality (AR) guidance systems. Secondary objectives examined risk factor assessment across demographic characteristics, surgical variables, and analysis of vertebral level-specific violation patterns. Summary of Background Data: Proximal FJV is a recognized complication of pedicle screw placement, with reported rates ranging from 2% to 42%. Although robotic-assisted techniques are associated with reduced FJV risk, direct comparisons between modern RAN and AR systems remain limited and warrant further investigation. Methods: Postoperative imaging was analyzed for proximal FJV in patients who underwent either RAN (Mazor X) or AR-guided (Xvision) pedicle screw placement. Patient demographics, surgical characteristics, and FJV rates were compared between groups. Results: Among 175 patients, a total of 350 proximal facet joints were evaluated, with an FJV rate of 5.8% (n = 11) in the RAN group and 9.4% (n = 15) in the AR group. The highest violation rates occurred at L5 (RAN: 13.2%, n=5; AR: 35.3%, n=12), without reaching statistical significance. Most violations were modified Park grade I (RAN: 6.3%, n=9; AR: 4.4%, n=7) or grade II (RAN: 1.6%, n=2; AR: 5.6%, n=8), with no grade III violations observed. Demographic factors showed no significant association with FJV rates. No revision surgeries were required for screw malposition or FJV. Conclusions: RAN demonstrated lower proximal FJV rates compared with AR guidance in lumbar and sacral pedicle screw placement, particularly at L5; however, this difference was not statistically significant. Although demographic factors showed no significant association with FJV occurrence, the absence of severe violations in both cohorts demonstrates the overall safety profile of these navigation systems.