Volar dislocation of the metacarpophalangeal joint of the thumb--a case report.

A patient with a volar dislocation of the metacarpophalangeal joint of the thumb is reported in which closed reduction proved impossible because of the interposition of the dorsal capsule, extensor pollicis longus tendon and extensor pollicis brevis tendon in the metacarpophalangeal joint. The collateral ligament was also ruptured. Therefore open reduction is recommended for similar cases.