Isolated complex dislocation of the metacarpophalangeal joint of the third finger.

Two unusual cases of isolated closed complex dislocation of the metacarpophalangeal joint of the third finger are presented. The single most important element preventing reduction was interposition of the volar plate between the proximal end of the phalanx and the head of the metacarpal, but the deep transverse ligament was also intimately involved in the entrapment mechanism. Such dislocations require open reduction as in the two cases presented, and we found the dorsal approach to be simple and effective.