Accuracy of Thoracolumbar Pedicle Screws Using Routine O-Arm Intraoperative Navigation - A 15-Year Review With Over 5000 Screws. A New Benchmark?

Abstract

A retrospective analysis was conducted on patients who underwent thoracolumbar and sacral pedicle screw insertion using intraoperative imaging and navigation between 2009 and 2023. Pedicle screw instrumentation is essential for stabilising the thoracolumbar spine, but precise placement is crucial to prevent complications like nerve injury, vascular damage, or pedicle fractures. While conventional techniques like freehand and fluoroscopy remain common, three-dimensional (3D) intraoperative navigation has significantly enhanced the safety and accuracy of spinal instrumentation. This study reflects on our 15-year experience with 3D navigation, analysing outcomes of a large series of patients. 3D intraoperative imaging and navigation is an assistive adjunct with higher rates of surgical accuracy when compared to conventional freehand and fluoroscopic techniques. Current literature reports accuracies of navigation-assisted pedicle screw placement ranging from 91.4% to 95.8%. However, these high levels of accuracies reported over the years were conducted in relatively smaller cohorts. Computed tomography (CT) images were obtained and analysed for signs of pedicle wall breach, which was graded according to the Gertzbein classification. Pedicle screw breach rates were computed thereafter. Analysis of 5,478 thoracolumbar pedicle screws implanted with intraoperative navigation guidance revealed a 98.63% insertion accuracy rate. The rate of major breaches was 0.55%, and the overall breach rate was 1.64%. There was no incidence of returning to the operating theatre for the revision of screws. Our analysis of 5,478 pedicle screws shows that O-arm navigation is safe and accurate, with a major breach rate of 0.55%. No patient in this cohort had any neurovascular injury, and the few screws with major breaches were fixed during the index procedure. There were no incidences of return to the operating theatre for malpositioned screws in our 15-year study.