Radiographic abnormalities of rheumatoid arthritis in patients with diffuse idiopathic skeletal hyperostosis.

Radiographic abnormalities of rheumatoid arthritis (RA) in 8 patients with diffuse idiopathic skeletal hyperostosis (DISH) included atypical features: lack of osteoporosis, bone sclerosis and proliferation about erosions, osteophytosis, and bony ankylosis. Atypical clinical features included a high incidence of flexion contractures of elbows, wrists, ankles, or knees. It is not surprising that bone production occurs about involved articulations in patients with RA-DISH, as the latter disorder is characterized by bony proliferation at sites of ligament and tendon attachment to bone in the axial and extraaxial skeleton, perhaps related to stress.