Ulnar-shortening osteotomy after fracture of the distal radius.

The ulnar impingement syndrome due to a relatively long ulna is one of the complications of a fracture of the distal radius. We performed ten ulnar-shortening osteotomies to restore distal radioulnar joint congruity. The mean relative ulna length was 4-5 mm. Insufficient bone healing was encountered in four osteotomies. Replating and cancellous bone grafting was necessary in two cases because of nonunion. The functional outcomes were good in six, fair in two, and poor in two cases. Nonunion and poor functional outcome were related to a malunion of the radius with a volar radiocarpal angle of 20 degrees or 25 degrees. It appeared that incongruity of the distal radioulnar joint favored nonunion.