Capsular tissues of the proximal interphalangeal joint: normal composition and effects of Dupuytren's disease and rheumatoid arthritis.

Three fibrocartilages associated with the proximal interphalangeal joint are described--at the attachment of the central slip to bone, within the slip where it passes over the joint, and the volar plate. Material was obtained at surgery following trauma, Dupuytren's disease and rheumatoid arthritis. The fibrocartilages were structurally distinct and immunolabelled differently with monoclonal antibodies to extracellular matrix components. All fibrocartilages from normal and Dupuytren's fingers contained chondroitin and keratan sulphate. Type II collagen was present in all attachment zones, although there was little in rheumatoid fingers. It was also present in the dorsal hood of some normal fingers, but not in pathological specimens or the volar plate. The results show that the fibrocartilages are dynamic tissues whose composition varies according to function and use, and changes in disease.