Pin-site radioulnar synostosis after external fixation of a distal radial fracture: two case reports.

Complications of distal radial fracture and external fixation are common, but the authors report, in two patients, a previously unrecognized complication, that of radioulnar synostosis. In both cases the proximally placed pins extended across the interosseous region, and the distal ends were adjacent to the ulna. Hematoma and osseous debris were introduced into the interosseous region. Several weeks after the external fixator was removed, the patients were noted to have a restricted range of pronation and supination. A radioulnar synostosis had formed across the interosseous region. Resection of the synostosis restored pronation and supination. With careful pin placement this complication will be avoided.