The Feasibility of Anterior Occipital Condyle Screw for the Reconstruction of Craniovertebral Junction: A Digital Anatomical and Cadaveric Study of a Novel Technique

Abstract Background: Anterior occipital condyle screw (AOCS) could be a feasible technique apply to the reconstruction of craniovertebral junction. This study was to analyze the feasibility of AOCS.Method: The craniovertebral junction computed tomography (CT) scans of 40 adults were enrolled and imported into Mimics software. Then the three-dimensional reconstruction digital model of craniovertebral junction were established to determine entry point, insertion angle and screw’s trajectory. After AOCS inserted into ten human cadaver spine specimens, CT scans were performed to verify the location between screws and important structures. Result: The optimal entry point is located caudally and medial to the ventral of occipital condyle. The optimal trajectory is in inclination angle (5.9°±3.4°) in the sagittal plane and diverge angle (26.7°±6.0°) in the axial plane with the screw length around 21.6±1.2mm. There were no screws invaded into hypoglossal canal and vertebral artery in all specimens.Conclusion: AOCS fixation is a feasible novel technique for anterior craniovertebral junction reconstruction, and it could be an effective alternative operation for anterior reconstruction with titanium mesh cage.