Posterior fusion for atlanto-axial subluxation in rheumatoid arthritis.

Posterior cervical fusion was performed in 34 patients with advanced rheumatoid atlanto-axial subluxation. Atraumatic surgical technique was used with local anesthesia and without skull traction. Intractable occipital rhizopathy and long-tract signs were the main indications. Anterior atlanto-axial subluxation in 28 patients was operated on with posterior fusion of C1-C2. Superior migration of the odontoid process into the foramen magnum in six patients was treated with posterior fusion of occiput C1-C2. Immediate mobilization in a plastic brace followed surgery. Average follow-up was 3 years. All patients became symptom-free, except for three who had remaining long-tract signs. Bony fusion was achieved in 17 patients; stable fibrous fusion, in 8 patients; and pseudoarthrosis, in 4 patients. There were no major postoperative complications. Five deaths occurred after 1-2 years from unrelated causes.