Surgical Intervention for Unstable Craniovertebral Junction Anomalies with Narrow C-2 Pedicle

OBJECTIVE: We sought to investigate and report a novel surgical technique of screws insertion and posterior surgical reduction, as well as explore its clinical results.METHODS: From September 2008 to September 2012, we treated 41 cases of unstable craniovertebral junction anomalies with a narrow C-2 pedicle at our department. All patients underwent " posterior reduction and internal fixation of the occipital bone with superior or inferior articular process of C-2 and lateral mass of C-3 on the narrowed C-2 pedicle side-for non-narrowed C-2 pedicle side, the screw was only inserted into C-2 pedicle without extending the fixation to C-3 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.RESULTS: A total of 134 screws were inserted into the C-2 pedicle (30 screws), superior (35 screws) or inferior (17 screws) articular process of C-2, and lateral mass of C-3 (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.CONCLUSION: This novel surgical technique is safe, feasible, and effective for the treatment of unstable craniovertebral junction anomalies with a narrow C-2 pedicle.