Background: Posterior cervical fixation with lateral mass screws (LMSs) and cervical pedicle screws (CPS) is well established, but free-hand and fluoroscopy-guided techniques remain limited by accuracy and safety concerns. Intraoperative O-arm navigation provides real-time three-dimensional (3D) imaging and may improve precision while reducing complications. This study evaluates screw accuracy, safety, operative parameters, and functional outcomes using O-arm-guided posterior cervical fixation. Methods: This ambispective observational cohort analyzed 147 screws placed under O-arm-based 3D navigation. Primary outcome was screw accuracy graded on intraoperative O-arm scans; secondary outcomes included breach rates, complications, operative metrics, blood loss, radiation dose, and functional scores (Visual Analog Scale VAS, modified Japanese Orthopaedic Association mJOA, Nurick, American Spinal Injury Association) assessed over 1 year. Results: Overall screw accuracy was 99.3%, with 146 screws fully contained and one C2 CPS showing a high-grade breach (0.7%) without neurological deficit. No wound infections, hardware failures, or reoperations were recorded. Functional outcomes improved significantly: mean VAS decreased from 5.5 to 1.8, mJOA increased from 12.6 to 14.3, and Nurick grade improved from 3.1 to 2.4 at 12 months (all P < 0.01). Average operative time was 236 min, blood loss 350 mL, and mean radiation dose 1145 mGy•cm. Conclusion: In this observational cohort of 147 screws for posterior cervical fixation with O-arm navigation, we achieved a screw placement accuracy of 99.3% with only one high-grade breach and no neurological deficits or reoperations
Hadgaonkar et al. (Fri,) studied this question.