Articular Cartilage Loss in Long‐standing Flexion Deformity of the Proximal Interphalangeal Joints

The difficulty in achieving full extension of the proximal interphalangeal joint after some years of fixation in full flexion is here explained by a study of joint surfaces resected after 15 years of full flexion in a hysterical woman. There was loss of articular cartilage and subchondral bone from the proximal phalangeal head where it was not in contact with the base of the middle phalanx. Even more important was the direct adhesion of the extensor tendon to this dorsal unused aspect of the proximal phalangeal head. Metaplasia from articular cartilage to fibrous tissue appeared to occur, and permanently prevented restoration of full extension of these joints .