Delayed union of fractures of the trapezoid and body of the hamate.

Delayed union of fractures of the trapezoid and body of the hamate are rare and difficult to treat. The fracture fragments may include the neighboring metacarpals with the insertions of the wrist extensors. These two cases occurred after direct blows to the bases of the 2nd and 5th metacarpals, respectively. The extensor carpi radialis longus and extensor carpi ulnaris are deforming forces that may delay osseous union when cast immobilization alone is used. Early internal fixation is advocated for even minimally displaced fractures of the trapezoid or hamate when accompanied by intra-articular fragments of metacarpal with their tendinous insertions.