A floating fifth metacarpal

A 33-year-old man injured his left little finger following a fall on his left hand with fist closed in a soccer match. He was transferred to the emergency room. The clinical examination revealed deformation, pain and functional impotence of the fifth finger of the left hand. Mobilization and palpation of the digit were painful along and there was no sign of a digital neurovascular lesion. X-rays showed a simultaneous dislocation of the fifth metacarpophalangeal and carpometacarpal joints (A). The treatment consisted of a closed orthopaedic reduction under loco-regional anaesthesia by external manoeuvres directed in the opposite direction of the injury followed by percutaneous Kirschner wires fixation under fluoroscopic guidance (B). The hand was immobilised for six weeks, then the wires were removed and began functional rehabilitation. The three-month check showed a painless stable carpometacarpal and metacarpiphalangeal joints with symmetrical extension and flexion of the little left finger. At the 16-month follow-up, the patient doesn´t complain of stiffness of the left little finger and there was no pain or chronic instability. A floating fifth metacarpal is very rare. In complex dislocation of the little finger metacarpophalangeal joint, the volar plate can be trapped in the joint space, making closed reduction impossible and indicating volar plate entrapment. In general the prognosis is favourable.