Benefits and Pitfalls of O-Arm Navigation in Cervical Pedicle Screw

BACKGROUND: Cervical pedicle screw (CPS) with Oarm-based intraoperative navigation has demonstrated satisfactory results in recent studies. In this article, we introduce our experience and discuss important considerations for CPS placement with O-arm navigation. METHODS: We retrospectively reviewed the data of 51 patients with 156 pedicle screws who underwent O-arm navigated CPS from July 2020 to October 2021. The accuracy of each screw placement was evaluated at the initial screw location using intraoperative 3D reconstructed O-arm images and the final screw location using postoperative computed tomography (CT). The screw accuracy was assessed in the axial image. RESULTS: The initial accuracy of screws on intraoperative 3D reconstructed O-arm images was 93.6% (146 of 156). The accuracies of the mid-cervical level (C3, C4, C5) were relatively low (83.3%-85.0%) compared with those of C2, C6, and C7 (93.3%-100.0%) at the initial screw due to the rotation of the vertebral body. Among 10 violated screws, 5 were converted to lateral mass screws or removed intraoperatively, and the other 5 were retained because the violations were minimal. After converting the screw, the final accuracy of the screws in postoperative CT was 96.7% (146 of 151). CONCLUSIONS: CPS with O-arm navigation showed relatively low accuracy at the mid-cervical level due to vertebral rotation. However, the opportunity to convert the screw from intraoperative 3D reconstructed O-arm images is the advantage of the O-arm navigation, and it showed excellent accuracy.