An extreme case of basilar invagination in rheumatoid arthritis of the cervical spine.

cervical disease is variable, but common, and has been observed in up to 90% of rheumatoid arthritis patients.1 However, the incidence of symptoms is less than the observed objective radiographic pathological changes.2,3 Basilar invagination can be seen in isolation or in combination with other instabilities. Although it occurs secondary to erosive changes in the atlantoaxial and occipitoatlantal joints, the detailed pathophysiology has not been described in detail. Additionally, despite recognition as a troublesome instability in myelopathy, end stages of superior migration of the odontoid are not widely described in the literature. This article presents an aggressive form of rheumatoid arthritis with substantial, endstage basilar invagination.