Carpometacarpal Fracture-dislocations

Overview

Fracture-dislocation of the carpometacarpal (CMC) joints of the ring and little finger are the most affected CMC joints and the dislocation may be accompanied by other hand injuries. Fracture-dislocation of the CMC joints of the ring and little finger are extremely mobile because of their saddle shape anatomy and loose ligamentous attachments. Missed and incorrect diagnosis is very frequent in metacarpal base injuries of the hand and results in impaired function and weak grip. In these lesions immediate reduction is imperative. Treatment options for these injuries include non-operative management, closed reduction with Kirschner wire fixation (K-wire) and open reduction with internal fixation (ORIF). In chronic CMC fracture-dislocations ORIF is mandatory. Although operative treatment is recommended in the literature in fracture-dislocation of the CMC joints of the ring and little finger, other authors, in specific cases, performed conservative treatment through immediate reduction and splint immobilization and this treatment can be sufficient.

Physical examination in carpometacarpal injuries reveals ulnar-sided pain, swelling, diffuse edema, a palpable lump and tenderness of the hand. Radiological examination include hand-wrist radiographs in the posteroanterior (PA), true lateral and 45º oblique views. A true lateral view of the hand may demonstrate the dislocation, although overlapping of the joints can mask the dislocation. On PA radiographs, Fisher et al. propose using the so-called M-line parallelism of the CMC joints. A break in this M-line suggests a dislocation. Another method is to draw metacarpal cascade lines on a PA radiographs. It is important to recognise the associate lesions, for example hamate fractures, because this fracture can change the prognosis, surgical planning and treatment. The investigators hypothesized that there is an interobserver variability to evaluate the carpometacarpal fracture-dislocation and associated lesions in x-rays are underestimated. The investigators propose a protocol with a CT scan to asses this lesions. The researchers hypothesised that surgical reconstruction would result in better clinical result and lower complications rate than non-surgical treatment.

Conditions