Odontoid upward migration in rheumatoid arthritis

Abstract
✓ Lack of correlation between the severity of rheumatoid subluxation of the upper cervical vertebrae and supposed absence of neurological damage has led to the erroneous supposition that this finding is innocuous. Incomplete autopsy studies in rheumatoid arthritis have failed to recognize the cause of death, despite previously proven dramatic occipito-atlanto-axial dislocations. The most feared entity of rheumatoid basilar invagination, namely “cranial settling,” is poorly understood. Between 1978 and 1984, the authors treated 45 rheumatoid arthritis patients who were symptomatic with “cranial settling.” This consisted of vertical odontoid penetration through the foramen magnum (9 to 33 mm), occipito-atlanto-axial dislocation, lateral atlantal mass erosion, downward telescoping of the anterior arch of C-1 on the axis, and rostral rotation of the posterior arch of C-1 producing ventral and dorsal cervicomedullary junction compromise. Cervicomedullary junction dysfunction has mistakenly been called “entrapm...