Fig. 5

A After cage implantation, screws were inserted below the bilateral C2 articular surface. B Postoperative sagittal computed tomography (CT) showed that the odontoid process had been reduced and the cage was inserted anteriorly between the bilateral joints. C, D, E, F The insertion point of the C2 screw was located below the bilateral C2 articular surface and in a small area above the vertebral artery. The screw was inserted medially as far as possible. G Postoperative sagittal T2 magnetic resonance (MR) image showing that the ventral spinal cord compression was completely relieved, and the ventral spinal cerebrospinal fluid (CSF) signal was recovered. At 13 months after surgery, CT showed that the odontoid process remained in the reduced state (H) and the atlantoaxial interarticular bone bridge was formed (I, J)