The pronator quadratus muscle after plating of distal radius fractures: is the muscle still working?

The purpose of this study is to define the function of the pronator quadratus muscle after plating of a distal radius fracture using anterior (volar) approach. Fourteen cases with volar plating after for a distal radius fracture were included in the study. Sixteen healthy volunteers were selected to determine the effect of dominant arm on pronation torque of the forearm for the control group. Biodex System 4 PRO (Biodex Medical Systems Inc., New York) torque meter was used for pronation torque measurement. In healthy volunteer group, there was no statistically significant difference in mean pronation torque values between the dominant arm and nondominant arms. The mean loss of pronator strength was 18.5 % and the mean loss of pronator durability was 12.9 % indicating a pronator insufficiency in the cases operated by a volar approach compared to uninjured forearm. Two patients among the operated group, who had further strengthening exercises beyond their own rehabilitation regimes, had improved pronator torque compared to uninjured forearm. In conclusion, the results of this study indicate that following volar plating of distal radius fractures, there is a significant loss in pronator strength of the forearm. As the two of the patients had improved pronator strength of their operated forearm, further rehabilitation regimes should be considered to prevent pronator weakness following volar plating for distal radius fractures.