Tomography of the Sacro-Iliac Joints

Abstract

Tomography of the sacroiliac joints confirms the frequency of varying degrees of joint fusion, especially in the anterior part of the joint, in elderly non-arthritic and osteo-arthritic subjects. Similar though more extensive changes were observed in younger paraplegic patients. Rheumatoid arthritic patients showed more frequent and more severe degrees of joint narrowing and fusion, but a minority also showed mild para-articular sclerosis and small erosions. Marked degrees of sacroiliac joint narrowing and fusion were found at an early age in ankylosing spondylitis. Para-articular sclerosis, marginal erosions and occasionally pseudo-widening of the joint space, were more prominent than in rheumatoid arthritis. Tomograms were much more useful for demonstrating joint narrowing and fusion compared with antero-posterior radiographs of the sacroiliac joints, but they are only slightly better for showing sclerosis, erosions and oateophytes around the joint.