The locked metacarpophalangeal joint: report of four cases and review of the literature.

Four cases of locked finger metacarpophalangeal joints are reported. Two of these cases were caused by entrapment of the sesamoid behind an exostosis off the second metacarpal head. The third was from subluxation of the dorsal interosseous tendon over a dorsal osteophyte on the metacarpal. The fourth was from an exostosis tethering the accessory collateral ligament. Surgical exploration using a palmar approach was the treatment of choice. All patients regained full range of motion within two months. A review of the various causes and treatment options for this unusual condition is presented.