Accuracy of a high-resolution augmented reality (AR) guidance system with novel 3D stereoscopic targeting for spinal surgery.

Background: Augmented reality (AR) is increasingly transforming the landscape of spine surgery by offering enhanced visualization of anatomical structures in real time, directly overlaid onto the surgical field. The study objective was to determine the accuracy of a novel high-resolution AR system with novel three-dimensional (3D) stereoscopic targeting in pedicle screw insertion and to compare it with published studies on existing AR, navigation, and robotic systems. Methods: Eighty pedicle screws were inserted using a novel high-resolution AR system (minimally invasive 55, open 25; thoracic 34, lumbosacral 46). Heary and Gertzbein-Robbins grading was applied, assessing the degree of pedicle breaches on postoperative CT scans. 3D measurements of positional error (PE) and angular error (AE) were performed by comparing post-operative CT scans of implanted screws with planned trajectories. Results: Seventy-six screws placed had Heary grade I. Four screws had a larger diameter than the pedicle and were planned with an in-out-in technique with an intended Heary grade II. Screw placement accuracy rate defined as the percentage of implantations with Heary grades I and II and Gertzbein-Robbins grades A and B was 100%. PE and AE (mean ± standard deviation) for the novel AR system were 1.1±0.5 mm and 1.3°±0.5°, respectively. Percent increment in PE and AE for different navigation, robotic, and AR systems compared to the novel AR system ranged between 23.7-80.6% and 40.6-79.5%, respectively, with the differences being highly significant for all comparisons. Conclusions: PE and AE for placing pedicle screws are 2-5× smaller for the high-resolution AR system with novel 3D stereoscopic targeting compared to published studies on existing navigation, robotic and AR systems. A PE of 1.1 mm and AE of 1.3° makes this technology particularly suited for small pedicles and challenging anatomy.