Accuracy of robot-assisted navigation in spinal and pelvic trauma

Abstract

Background: In the future, the importance of robot-assisted techniques in trauma surgery will increase significantly, especially in the context of spinal and pelvic surgery. Therefore, a retrospective analysis of the already robot-assisted inserted screws is essential to determine the precision of the postoperative screw position in relation to the preoperative planning images. It is generally assumed that the implantation of screws as part of a surgical procedure using a robot is more precise than surgical procedures performed without the use of a robot. This is due in particular to the assistance provided by the robot when positioning the screws in the vertebral body or the pelvic bone. Methods: The present study is an observational study of patients who underwent surgery with the robot-assisted navigation system "Excelsius GPS" at the Department of Orthopaedics and Traumatology of the Medical University of Graz after a traumatic pelvic or spinal injury between October 2, 2023 and June 25, 2024. Patients were required to be at least 18 years of age. Furthermore, it was imperative that the preoperative and postoperative CT images were of sufficient quality to ensure accurate measurement of the screw position. A total of 130 screws from 21 patients were measured in the spine, while six screws were measured in the pelvis of three patients. Subsequently, the discrepancies in screw position between preoperative planning images and postoperative CT images were subjected to statistical processing and analysis. Results: A total of 650 differences between the 130 pre-planned screws and the installed screws in the spine were determined during the investigation. Based on the measurement results, it was determined that 92.92% of the 650 measured differences showed a deviation of less than 2 mm from the planned screw position. In 98.77% of cases, a deviation of less than 5 mm was found. An analysis of the screws used in the project revealed that only 1.23% of the screws showed a deviation of more than 5 mm from the planning images. The median with the smallest deviation of 0.032 was observed at the screw tip in the transverse plane, while the smallest range is the screw tip in the sagittal plane. A significant difference was found in four out of five differences in the individual spinal segments. The factors gender and side, whether left or right, showed no significant differences. The present study concludes that 76 % of the 30 differences recorded in relation to the pelvic screws had a value of less than 1 mm, while 100 % of the differences had a value of less than 3 mm. Conclusion: The results of the study indicate a high degree of congruence between the postoperative screw position and the pre-planned position. The majority of discrepancies observed in measurements of 5 mm are attributable to the values obtained for "diff.tip/vb" or "diff.tip/b", which denote the penetration depth of the screw. It was determined that this value is not of particular relevance, as the surgeon generally fixes the screw manually and thus determines the penetration depth of the screw.

Datum der Bewilligung	2025
Originalsprache	Englisch
Gradverleihende Hochschule	Medizinische Universität Graz
Betreuer/-in	Paul Puchwein (Betreuer*in) & Nicolas Eibinger (Mitbetreuer*in)