Robot-Assisted Percutaneous Pedicle Screw Placement: Evaluation of Accuracy of the First 100 Screws and Comparison with Cohort of Fluoroscopy-guided Screws.

OBJECTIVE

Percutaneous pedicle screws (PPS) are used to stabilize the spine after interbody fusion in minimally invasive approaches. Recently, robotic assistance has been developed to improve the accuracy of PPS. We report our initial experience with ExcelsiusGPS and compare its accuracy with our historical cohort of fluoroscopy-guided PPS.

METHODS

We reviewed prospectively collected data from our first 100 robot-assisted PPS. We graded accuracy of screws on computed tomography imaging and compared it with a previous cohort of 90 PPS placed using fluoroscopy. We also analyzed the effect of various demographic and perioperative metrics on accuracy.

RESULTS

We placed 103 PPS in the first 20 consecutive patients with postoperative computed tomography imaging using ExcelsiusGPS. All screws were placed at L2 to S1. Our robot-assisted cohort had 6 breaches, with only 2 breaches >2 mm, yielding an overall breach rate of 5.8% and a significant breach rate of 1.9%. In comparison, our fluoroscopy-guided cohort had a breach rate of 3.3% and a significant breach rate of 1.1%, which was not significantly different. More breaches occurred in the first half of cases, suggesting a learning curve with robotic assistance. No demographic or perioperative metrics had a significant effect on accuracy.

CONCLUSIONS

Our breach rates with ExcelsiusGPS were low and consistent with others reported in the literature, as well as with other robotic systems. Our series shows equivalent accuracy of placement of PPS with this robotic platform compared with fluoroscopic guidance and suggests a relatively short learning curve.