Rheumatoid arthritis of the thoracic and lumbar spine.

We report seven cases of patients with seropositive rheumatoid arthritis in whom involvement of the thoracic and lumbar vertebrae occurred. Histological corroboration is presented in four. Pathological lesions comprised various combinations of paravertebral joint erosions, erosive discitis, anteroposterior and rotatory instability, major lumbar nerve root compression, and vertebral collapse. Specific radiological features are presented, enabling a distinction to be made between pure degenerative spondylosis and rheumatoid spondylitis. We submit that subcervical rheumatoid spondylitis is commoner than is generally believed, though less common than rheumatoid involvement of the cervical spine.