Background:

Calibration of computer navigation for spinal fusion is most commonly conducted using either a preoperative computed tomography (CT) scan or intraoperative O-arm scanning. This study aimed to directly compare patient radiation exposure from intraoperative O-arm use for pedicle screw placement versus typical diagnostic lumbar spine CT studies.

Methods:

A retrospective review of patients undergoing O-arm navigated lumbar spine fusion procedures was performed to record radiation exposure as the primary outcome, as well as surgical and demographic details. The same was done for a control group of patients undergoing lumbar spine CT scans.

Results:

A total of 83 patients undergoing lumbar spine fusion with O-arm navigation were included, as well as 105 unique patients who underwent a lumbar spine CT. The 2 groups were similar in terms of average age (60.2 versus 60.5, P = .90), average height (170 cm versus 169 cm, P = .50), and average weight (92.6 kg versus 90.9 kg, P = .62). Dose-length product for O-arm navigated procedures was 798.3 mGy-cm and 924.2 mGy-cm for CT scans (P = .064). Subgroup analysis revealed 18 patients who had both an O-arm navigated surgery and a lumbar spine CT. In this group the average dose-length product for O-arm surgeries was 806.2 mGy-cm and 822.1 mGy-cm for CT scans (P = .92) CONCLUSION: This study revealed no statistically or clinically significant differences between patient radiation exposure for O-arm operative navigation compared to lumbar spine CT.

Clinical relevance:

Given the similarity in radiation exposure, surgeons should rely on other factors to guide decision making in regard to mode of imaging for navigation. Knowledge of this comparison and total radiation exposure will also be useful for patient education and shared decision making in regard to navigated procedures.