[Carpometacarpal dislocation of the fifth finger: descriptive study of 31 cases]

Carpometacarpal dislocation of the little finger is a rare and little known injury. We performed a 10 years retrospective study of all the cases in our unit in order to improve comprehension and treatment of this disease.

Thirty-one patients were included in this study. All the dislocations were dorsal with 5 isolated fifth carpometacarpal dislocations, 6 fracture-dislocations of the base of the fifth metacarpal, 19 fourth and fifth dislocations and one third-fourth-fifth dislocation. Diagnosis of the injury was made early in only 19 patients. 30 had surgical management, 28 with percutaneous K-wires, and 2 through a metacarpalhamate arthrodesis.

Twenty-six patients were available for follow-up at an average of 6 months and 5 patients were lost for follow-up. Twenty-five patients had satisfactory results. A reflex sympathetic dystrophy delayed the recovery for one patient. There was no recurrence of dislocation at follow-up. There was no complication necessitating revision surgery.

Diagnosis of carpometacarpal dislocation of the little finger can be performed with conventional radiographic examination; computer-tomography is helpful to confirm an associated fracture of the carpus. The goal of treatment is early reduction and fixation of the metacarpal. There is no recommendation for operative technique based on scientific evaluation. Early diagnosis is the key to success.