An Intraoperative Trajectory‐Determined Strategy of Patient‐Specific Drill Template for <scp> C 2 </scp> Transoral Pedicle Insertion in Incomplete Reduction of Atlantoaxial Dislocation: An In Vitro Study

Objectives This study aims to explore a novel intraoperative trajectory-determined strategy of grouped patient-specific drill templates (PDTs) for transoral C2 pedicle screw insertion (C2 TOPI) for atlantoaxial dislocation (AAD) with incomplete reduction and to evaluate its efficiency and accuracy. Methods Ten cadaveric C2 specimens were scanned by computed tomography (CT) and randomly divided into two groups (the PDT and freehand groups). A novel intraoperative trajectory-determined strategy of grouped PDTs was created for AAD with incomplete reduction. C2 TOPI was performed by use of the PDT technique and the fluoroscopy-guided freehand technique. After surgery, the screw deviations from the centroid of the cross-section at the midpoint of the pedicle and screw position grades were assessed in both groups. Results Compared to the freehand group, the PDT group had a significantly shorter surgery time than the freehand group (47.7 vs 61.9 min, P 0.05). Conclusion The novel intraoperative trajectory-determined strategy of grouped PDTs can be used as an accurate and feasible method for C2 TOPI for AAD with incomplete reduction.