Background: The C2 transpedicular screw trajectory does not have an exact guideline for the screw placement because the anatomical variation in this region could results in injury to the vertebral artery during surgery.

Objective: To assess the accuracy and safety for C2 transpedicular screw placement by freehand under lateral fluoroscopy with an anatomical landmark using the direct visualization technique.

Materials and Methods: The present study was a retrospective data that reviewed 19 consecutive patients who underwent C2 transpedicular screw fixation by freehand placement with lateral fluoroscopic-guided and an anatomical landmark by direct visualization technique between March 2017 and February 2019 in Pathum Thani Hospital. The preoperative CT cervical spine was evaluated before the operation and postoperative CT angiogram images of the neck were taken in all patients after they were clinically stable to evaluate the vertebral artery and accuracy in the transpedicular screw placement.

Results: An anatomical landmark by direct visualization technique is accurate and safe for C2 transpedicular screw placement.

Conclusion: The C2 transpedicular screw insertion should be positioned using clear anatomical landmarks and determined by direct visualization to avoid vertebral artery injury during surgery.

Keywords: C2 transpedicular screw, Vertebral artery injury, Anatomical landmark, The anatomical visualized technique

DOI: doi.org/10.35755/jmedassocthai.2020.08.10864

Received 18 Nov 2019 | Revised 5 Mar 2020 | Accepted 6 Mar 2020