Locking of the metacarpo-phalangeal joint from a loose body. Report of a case

1. Locking of the metacarpo-phalangeal joint from articular derangements is rare. 2. A case due to an intra-articular loose body is described. 3. The literature is reviewed. The commonest cause is catching of the volar capsule or collateral ligaments on osteophytes about the metacarpal head, but intra-articular bands, incongruities of the articular surface and entrapment of the sesamoid have also been described. 4. An analysis of the reported cases suggests the likely cause in the individual patient. 5. Operation is usually required to restore joint motion.