External fixation of distal radial fractures: four compared with five pins: a randomized prospective study

The purpose of this study of distal radial fractures was to compare the radiographic and clinical results after use of a standard four-pin external fixator with those after use of a five-pin fixator with the fifth pin stabilizing the distal radial articular fragment.

In an open prospective trial, fifty patients with an unstable distal radial fracture were randomized for treatment with closed reduction and either a standard small Association for the Study of Internal Fixation (ASIF) four-pin fixator (twenty-five patients) or a five-pin external fixator (twenty-five patients). The fixators were removed at nine weeks, and all patients were assessed radiographically and clinically at six months.

Follow-up radiographs demonstrated significantly less loss of alignment and length with the five-pin external fixator. Pin site infections were more prevalent with the four-pin fixator. The range of motion of the wrist and forearm, the grip strength, and the Lidstrom functional ratings at six months were all significantly better after use of the five-pin fixator.

The use of a five-pin external fixator, with the fifth pin stabilizing the distal radial articular fragment, yields better radiographic and functional results than does a four-pin fixator.