Introduction
The capitate is the largest carpal bone, though it is not the most frequently fractured, and is rarely fractured in isolation. Injuries to the capitate are often part of complex injuries. Capitate fractures are sometimes seen along with scaphoid waist fractures or distal radius fractures.
Anatomy
The capitate articulates distally with the bases of the third and fourth metacarpals and proximally with the scaphoid and lunate. The trapezoid and the hamate are lateral (radial) and medial, respectively.
Classification
Capitate fractures are classified by the anatomic location of the fracture, along with what other concomitant injuries may be present. The combination of a capitate fracture and a scaphoid waist fractureis known as "scaphocapitate syndrome" .
The force of injury in this syndrome can propagate leading to perilunate dislocation as well.
Presentation
A direct blow to the hand, usually from a fall, is implicated.
Diagnosis
It is important to exclude additional ligamentous or bony injuries.
Treatment
Non-displaced capitate fractures need to be immobilized only. Displacement is an indication for fixation, as is concomitant surgery on the scaphoid; that is, if the scaphoid is fractured it will be fixed, and at that setting the capitate fracture may be fixed as well. Surgical fixation is with a K-wire or a screw, with bone graft added for significant comminution.