Isolated dislocation of the four ulnar carpometacarpal joints.

Dislocation of the multiple carpometacarpal joints without associated fractures of the metacarpal and/or carpal bones is an exceedingly rare injury. An earlier belief that carpometacarpal dislocations are high-energy injuries is questioned due to an unusual case of isolated dislocation of the four ulnar metacarpals that occurred after a relatively minor hand trauma. Early recognition and anatomical reduction are essential to achieving good long-term outcomes. Massive edema, interposed volar ligaments and overlapping metacarpal bases are the usual obstacles to a successful closed reduction.