S2 Alar-Iliac Screw Insertion Safety With Augmented Reality-Assisted Surgical Navigation.

Introduction: Augmented reality (AR) technology has existed for decades but is not commonly used in spine surgery. Studies have found AR to have a good safety profile and workflow advantages over robotic navigation in pedicle screw placement. This study evaluates the safety and accuracy of AR navigation with S2 alar-iliac (S2AI) screw placement, an area with challenging surgical anatomy and little published research.

Methods: A retrospective chart review was conducted on patients undergoing spine surgery involving the S2AI corridor between November 2022 and September 2024 at two large academic medical centers. Patient and screw information was collected, and radiographs and CT scans were analyzed for screw safety and accuracy.

Results: All 70 screws analyzed fully penetrated the sacroiliac joint with only one screw breaching the pelvis medially and no screws breaching the greater sciatic notch. No complications were found in the S2AI corridor.

Conclusion: The S2AI corridor contains high-risk neurovasculature. Studies have demonstrated the superiority of robotic navigation over freehand navigation in this area. AR is noninferior to robotic navigation. AR, however, has radiation exposure, workflow, and training advantages over robotic navigation. Future work should investigate patient-reported outcomes, cost-benefit, and learning curve.