Tomographic examinations of sacroiliac joints in adult patients with rheumatoid arthritis.

Tomography of the sacroiliac joints (SIJ) was performed in 72 patients with rheumatoid arthritis (RA) and in 50 controls. Twenty-seven rheumatoid patients (38%) showed typical sacroilitis with predominantly severe intraarticular ankylosis and subchondral erosions. Fourteen patients (19%) had a probable sacroilitis with mild erosions and intraarticular ankylosis and concomitant degenerative changes. Fifteen patients (21%) showed predominantly degenerative changes and 16 RA patients (22%) had no radiological manifestation of the SIJ. There was no relation between typical sacroilitis and age of patients, duration of disease, rheumatoid factor, Steinbrocker's stage and frequency of HLA B27.