Preliminary analysis of a follow-up study of one hundred patient with rheumatoid arthritis has lead to the following tentative conclusions: AAS is a common complication of rheumatoid arthritis. The incidence of AAS correlates with the duration of the disease. AAS is not necessarily associated with progressive myelopathy. AAS does not significantly affect survival in rheumatoid arthritis. AAS alone is not an indication for surgical operation, but this should be considered when there is intractable pain or progressive myelopathy.