Assessment of pronator quadratus repair integrity following volar plate fixation for distal radius fractures: a prospective clinical cohort study.

PURPOSE: To assess prospectively the integrity of pronator quadratus (PQ) muscle repair following volar plate fixation of distal radius fractures and to compare the clinical and radiographic outcomes of durable versus failed repairs in 24 subjects. In addition, by grading the degree of PQ injury, an attempt was made to correlate failure of repair with the PQ injury severity.

METHODS

The extent of PQ injury was graded for each fracture. After fracture fixation, the PQ muscle was repaired along its radial and distal borders. Radiopaque hemoclips were attached to each side of the PQ repair, 2 radially and 2 distally. The distance between these markers at time 0 versus x-rays taken at approximately 2 weeks, 6 weeks, and 3 months was recorded. Clip displacement of 1 cm or more compared to time 0 indicated repair failure.

RESULTS

One of 24 repairs (4%) failed at 3 months. No statistical difference was noted between the type of PQ injury and wrist flexion/extension, pronation/supination, and grip strength.

CONCLUSIONS

Pronator quadratus repairs after volar plate fracture fixation are generally durable. They withstand forces that occur at the distal radius during the healing process with a 4% failure rate. No correlation was shown between type of PQ injury and radiographic failure of the repair.