Comparison of Radiation Exposure Between O-Arm Navigated and C-Arm Guided Screw Placement in Minimally Invasive Transforaminal Lumbar Interbody Fusion

Instrumentation in minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is highly dependent on image guidance. Guidance with fluoroscopy (C-arm) and cone-beam computed tomography (O-arm) with navigation are common options. The intraoperative radiation exposure to patients with the different image modalities has not been compared, however. The present study aimed to compare the radiation exposure of the C-arm guidance and O-arm navigation techniques during MIS-TLIF surgery. Ninety consecutive patients who underwent MIS-TLIF for degenerative lumbar pathologies were retrospectively reviewed. The patients were divided into the C-arm guided (CG) and the O-arm navigated (ON) groups (45 patients in each group), and the radiation dosage reports were analyzed for comparison of radiation exposure. The ON group had a higher average effective radiation dose (1.99 ± 0.4 mSv vs. 0.91 ± 0.3 mSv). For patients with more than 2 interbody fusion levels (≥6 pedicle screws), the effective dose per screw was similar in the CG and ON groups (0.22 ± 0.08 mSv vs. 0.23 ± 0.05 mSv). As the body mass index increased, the per-screw effective dose of the CG group showed a significant positive trend, compared with a nonsignificant negative trend in the ON group. For level 1 MIS-TLIF (4 percutaneous screws), patients in the ON group had almost double the radiation exposure as those in the CG group. For level ≥2 (≥6 screws) or obese patients, the O-arm with navigation has the advantage of similar radiation exposure to the patient and less (almost no) radiation to the operating room staff.