The dorsal plate of the proximal interphalangeal joint

There exists on the articular surface of the central slip of the extensor tendon slip overlying the P.I.P. joint a constant structure which is morphologically similar to the patella of the knee joint and histologically similar to the fibro-cartilaginous palmar plate of the P.I.P. joint. It has been termed the dorsal plate. A study of 70 fingers, including 30 examined under magnification and 20 examined histologically, confirmed its constant presence and structure. Its functions appear to include stabilisation of the central extensor tendon and participation in stabilisation of the proximal interphalangeal joint.