Bennett's fracture (Fig. 8) is an oblique volar coronal fracture through the thumb metacarpal base, with the smaller fracture fragment remaining attached to the volar carpometacarpal ligament. The unresisted force of the abductor pollicis longus tendon results in proximal and radial subluxation of the larger metacarpal fragment, carrying the entire thumb with it. Reversed Bennett's fracture (Fig. 8) is a similar fracture-dislocation of the small finger metacarpal base. In analogous fashion, the force of the extensor carpi ulnaris attached to the larger fracture fragment produces instability requiring fixation. In either of these variations, closed reduction and percutaneous fixation of the metacarpal base to the proximal carpal bone is straightforward and satisfactory. The ring and small metacarpal bases may sustain a combined fracture-dislocation injury associated with a dorsal hamate fracture, also usually amenable to percutaneous fixation. Rolando's fracture refers to a comminuted intraarticular fracture of the thumb metacarpal base. Unlike Bennett's fracture, the additional comminution makes percutaneous fixation much less satisfactory. Although technically difficult, open reduction and internal fixation gives the best chance of restoring a working joint surface.
Metacarpal Fracture Dislocation