Abstract
A case of irreducible dislocation of the metacarpophalangeal joint of the thumb is reported. A 51-year-old woman was involved in a motorcycle accident, recieving a bruise on her left hand. Examination showed that the thumb was swollen and positioned in slight flexion and abduction at the metacarpophalangeal joint. Radiographs showed radial dislocation of the metacarpophalangeal joint of the thumb. Because closed reduction was unsuccessful, open reduction was required. The adductor apponeurosis was interposed between the metacarpal and proximal phalanx, which blocked reduction. The ulnar collateral ligament was avulsed from the proximal phalangeal attachment and folded. The dorsal capsule was also teared extensively. The thumb was immobilized for 6 weeks, and range of motion exercise was begun. A review of literature indicates that this pathologic anatomy has been described only by Stener.
