A tangential radiographic projection for demonstrating involvement of metacarpal heads in rheumatoid arthritis.

Abstract

The earliest changes in a joint affected by rheumatoid arthritis are in the peripheral crypts near to the attachments of the capsule to bone. Progressive inflammation and proliferation of the synovium is followed by its extension over the articular cartilage as a pannus, or by invasion of the bone near to the capsular attachments where it is not covered by articular cartilage. It is this invasion of bone which gives the typical erosions seen on radiographs and may lead to juxtarticular collapse. At the same stage ligaments may become elongated or may rupture. In recent years an increasing number of early synovectomies have been performed in an attempt to prevent this synovial invasion. Pain is relieved and recurrence is relatively rare, but the operation is not likely to be successful once radiological evidence of bone erosion has developed. Operations on metacarpo-phalangeal joints have shown that the earliest synovial proliferation and bone erosions are commonly under the collateral ligaments, with eros...