Distal radius fractures: a comparison of tension band wiring versus ulnar outrigger external fixation for the management of distal radioulnar instability.

PURPOSE: To retrospectively compare the results of immobilization of the forearm in supination with the results of tension band fixation of the ulnar styloid in 35 patients with distal radius fractures, fracture of the base of the ulnar styloid, and distal radioulnar joint instability treated with external fixation.

METHODS: Thirty-five patients with fractures of the distal radius, fracture of the base of the ulnar styloid, and unstable distal radioulnar joint had external fixation with adjunctive percutaneous pins and allograft bone to reduce and stabilize the distal radius fracture anatomically. Only those patients with an associated ulnar styloid base fracture displaced over 2 mm with gross distal radioulnar joint instability relative to the contralateral wrist were included in this study. Group 1 consisted of patients in whom the ulnar styloid base fracture was treated with conventional tension band wiring techniques. Group 2 patients were treated with a supplemental outrigger from the external fixator to the ulna and locked in 60 degrees of forearm supination. Groups 1 and 2 had an average follow-up period of 40 and 36 months, respectively.

RESULTS: Group 2 had significantly better supination than group 1. In terms of functional outcome it was found that there was no significant difference for the Disabilities of the Arm, Shoulder, and Hand and the Gartland and Werley scores between the 2 treatment groups. There was a lower rate of complications and fewer secondary procedures were required in group 2. The incidence of distal ulna resection was 4 of the 35 patients (2 patients in each group).

CONCLUSIONS: Our results indicate that patients in whom the ulnar styloid can be reduced and maintained in supination can be treated effectively with fixed supination outrigger external fixation. This method resulted in a statistically significant improvement in supination and a lower rate of distal radioulnar joint complications, and it required fewer secondary procedures.