External fixation of distal radius fractures: effect of distraction and duration.

PURPOSE: To assess the effects of the amount of distraction across the wrist and the duration of fixator placement on the clinical outcome of patients with distal radius fractures treated with external fixation.

METHODS

A total of 42 patients with closed distal radius fractures were treated with a spanning external fixator plus supplementary percutaneous K-wires over a 6-year period. All fractures were extra-articular (A type) or simple intra-articular (C type). Twenty-four of these patients were evaluated retrospectively for clinical and radiographic outcomes at an average follow-up time of 22 months (range, 4-49 months). The amount of distraction attained by the fixator was determined by measuring the carpal height ratio on plain radiographs. Wrist and forearm range of motion were recorded, as well as grip and pinch strength. Standard radiographs were taken to evaluate healing and bony alignment.

RESULTS

Using the Gartland Werley classification, there were 11 excellent, 10 good, and 3 fair results. Statistical analysis indicated that a higher carpal height ratio at the initial reduction positively correlated (p = .041) with an excellent outcome. Duration of external fixation did not have a significant impact on the final outcome within the parameters studied (p = .891). Average wrist range of motion at follow-up was as follows: flexion, 54.1 degrees (75% of the contralateral side); extension, 59.0 degrees (78%); radial deviation, 18.0 degrees (85%); ulnar deviation, 22 degrees (73%); pronation, 79.0 degrees (95%); and supination, 76.6 degrees (93%). None of the individual components of range of motion were negatively correlated with higher carpal height ratio at fixator application or duration of fixation, within the parameters studied.

CONCLUSIONS

Moderately increased distraction of the carpus at the initial fracture reduction is correlated with improved clinical outcome and does not have an adverse affect on subsequent wrist range of motion.

TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.