Cross-union complicating fracture of the forearm. Part I: Adults.

The cases of twenty-eight adults who had cross-union as a complication of fractures of the forearm were analyzed according to a new classification system. Four cross-unions were Type 1 (distal intra-articular part of the radius and ulna); fourteen, Type 2 (middle third or non-articular part of the distal third of the radius and ulna); and ten, Type 3 (proximal third of the radius and ulna). Type-1 cross-union occurred rarely, but it developed most commonly after closed reduction of a fracture. Types 2 and 3 typically followed severe local trauma and delayed open reduction. Bone fragments left in the interosseous space and bone screws that broached the opposite part of the cortex were common findings. Seventeen cross-unions were excised. Three of the four Type-1, none of the ten Type-2, and two of three Type-3 cross-unions recurred. The results after excision of Type-2 cross-unions in our series were far better than other results that have been previously reported.