Idiopathic Inflammations of Joints

Abstract

The inner part of the joint capsule, the synovial membrane, plays an essential role in the biology, function, and pathology of the joints. By virtue of its structure, a richly vascularized loose connective tissue delimited on its surface by the very reactive synoviocytes, the synovial membrane is the first of the articular components to participate in any inflammatory condition of a joint. Anatomopathological and histopathological examinations [603, 1436, 1543] show that inflammation of the synovial membrane by itself may occur without affection of the other joint constituents and may remain confined to this tissue. The conclusion drawn from such findings is that synovitis can occur as an entity by itself. While most inflammations of joints primarily affect the synovial membrane and later expand to other constituents of the joints, synovitis—strictspeaking — refers to those conditions in which clinical and roentgenographic examinations on long-term follow-up provide no evidence of extrasynovial involvement.