In Brief:
Patients with rheumatoid arthritis (43.6% of 140) initially without cervical involvement develop cervical instabilities, 12.9% exhibit aggravated instabilities, and 4.3% present canal stenosis with direct relevance to myelopathy during 6.0 ± 0.5 years. Established mutilating changes, progressive development into mutilating changes, and concomitant corticosteroid treatment indicate poor prognosis of the cervical spine in rheumatoid arthritis.