Diseases of the upper cervical spine tend to cause severe instability, motor, sensory and respiratory disorders. We evaluated 27 patients who underwent upper cervical spine operations at our hospital to 1990. The patients consisting of 7 males and 20 females were followed up postoperatively for 3 months to 11 years (mean follow-up: 7 months and 3 years). Thirteen patients had rheumatoid arthritis, 5 congenital anomalies, 2 cerebral palsy, and 4 suffered traumatic injuries. We divided the atlanto-axial subluxation patients into 2 groups, H and V. The H group consisted of patients with horizontal dislocation. While the V group consisted of patients with vertical dislocation. Those in the H group were for the most part moderately young RA, congenital, traumatic patients, and those in the V group were old female RA patients. Most of the male patients were congenital and traumatic, with 6 belonging to the H group. In both groups, ADL and pain improved, but severe myelopathic symptoms did not improved significantly. After several days' halo-vest reducation, posterior spinal fusion, and bone graft were performed on each patients. In patients with vertical dislocation, C1 decompression was necessary; but because of instability after one fascet fusion and impossible to reduce, occipital fusion was performed. Both groups showed improvement inatlanto-axial instability. Improvement of ADI was better in the H group, which may be due to decreased pain.
