Isolated Volar Dislocation of the Fifth Carpometacarpal Joint.

Isolated dislocation of the carpometacarpal (CMC) joints is a rare injury that accounts for less than 1% of hand injuries. Few cases of isolated volar dislocations of the fifth CMC joint have been reported, making such injuries worthy of reporting. Given the rarity of these injuries, they are easily overlooked in the emergency setting and thus require a high index of clinical suspicion. A 57-year-old female sustained an isolated volar dislocation of the fifth CMC joint when she fell onto her outstretched right hand. Physical examination revealed an inability to move the fifth digit, and the patient reported severe pain over the ulnar aspect of her right hand. X-rays of the right wrist revealed the dislocation. The patient was managed with closed reduction and application of an ulnar gutter splint. Solitary dislocations of any CMC joint are less common than simultaneous dislocation of multiple CMC joints, especially at the fifth CMC joint with volar dislocation. Because of the potential long-term adverse effects of untreated dislocations, these injuries must not be overlooked. Thus, patients presenting to the emergency department after traumatic injury involving an axial loading force to the hand should be carefully evaluated.