Fig. 2

Intraoperative details of the placement of C2 subfacetal screws. A A cage was placed after bilateral lateral mass joints were released under the microscope, which increased the distance from the C2 superior articular process to the occipital bone, thus increasing the operative space for screw placement. B The screw entry point is located in the space above the vertebral artery and below the posterior edge of the C2 superior articular surface. The blue dot is the screw entry point of the C2 subfacetal screw. C The screw entry direction should be inclined to the inside as far as possible to enable insertion in the anterior vertebral body. D Finally, the titanium rods were shaped, and the occipital screws were connected