The rheumatoid cervical spine: signs of instability on plain cervical radiographs.

The cervical spine is a common focus of destruction from rheumatoid arthritis, second only to the metacarpophalangeal joints. Joint, bone and ligament damage in the cervical spine leads to subluxations which can cause cervical cord compression resulting in paralysis and even sudden death. Because many patients with significant subluxations are asymptomatic, the radiologist plays a key role in recognizing the clinically important clues to instability on plain radiographs of the cervical spine-often difficult in rheumatoid arthritis when the bony landmarks are osteoporotic or eroded. This review focuses on the signs of instability on plain radiographs of the cervical spine, using diagrams and clinical examples to illustrate methods of identifying significant subluxations in rheumatoid arthritis.