Surgical Intervention for Unstable Craniovertebral Junction Anomalies with Narrow C₂ Pedicle

We sought to investigate and report a novel surgical technique of screws insertion and posterior surgical reduction, as well as explore its clinical results.

From September 2008 to September 2012, we treated 41 cases of unstable craniovertebral junction anomalies with a narrow C₂ pedicle at our department. All patients underwent "posterior reduction and internal fixation of the occipital bone with superior or inferior articular process of C₂ and lateral mass of C₃ on the narrowed C₂ pedicle side-for non-narrowed C₂ pedicle side, the screw was only inserted into C₂ pedicle without extending the fixation to C₃ vertebrae-using a titanium screw-rod (plate) fixation system." The preoperative and postoperative atlantodens interval, Chamberlain line, McRae line, and cervicomedullary angle were all measured. In addition, the preoperative and postoperative Japanese Orthopedic Association score was used to evaluate the cervical myelopathy.

A total of 134 screws were inserted into the C₂ pedicle (30 screws), superior (35 screws) or inferior (17 screws) articular process of C₂, and lateral mass of C₃ (52 screws). There was a significant statistical difference between the preoperative and postoperative results in the reduction of the odontoid process, decompression of the upper cervical spinal cord and medulla, as well as the improvement of neurologic functions (P < 0.05). All patients have exhibited a major neurologic improvement and solid bony fusion.

This novel surgical technique is safe, feasible, and effective for the treatment of unstable craniovertebral junction anomalies with a narrow C₂ pedicle.