Abstract

Design: Prospective, controlled, multi-center, cadaveric study, evaluating efficacy of miniature robotic guidance for percutaneous pedicle screws. Methods: Twelve cadavers, 234 screws, 17 surgeons (T9-S1). Accuracy (post-procedural CT), fluoroscopy time, radiation exposure (badge and ring dosimeters) and procedure time were measured. Results: Mean accuracy was 2.6 mm (std 0.7mm) for control; 1.1 mm (0.4) for study group. Control averaged 136 mrem X-Ray exposure per surgeon; 4.2 in study group. 13 of 15 surgeons in study group (87%) experienced radiation levels below measurable threshold. Average radiation dose for control was 10.1 mrem/screw, with average fluoro time/screw 27.6 sec; 0.2 mrem and 1.2 sec respectively in study group. Average procedure time for control was 1:59 hours (ave. 19 screws), compared with 1:14 hr (20 screws) for new robotic users and 0:49 hr for experienced (18 screws). Average time per screw was 6:16 minutes (std 3:03 min), 4:03 minutes (1:05 min) and 2:45 minutes respectively. Conclusions: Use of miniature, bone-mounted robotic guidance for percutaneous pedicle screws resulted in accuracy twice better than free hand. 56 times lower radiation and 23 times shorter fluoroscopy were observed, with time savings of 36% - 56%. Across all measures, robotic guidance improved performance and reduced variations between surgeons.