72 patients with isolated, closed fractures of the distal radius were randomized to receive either pronator quadratus muscle repair or no muscle repair during fracture reduction and consecutive volar plate fixation. The purpose of the study was to determine how effective the muscle repair was during a 3 month rehabilitation period, with a primary focus on forearm pronation strength. The results displayed no significant differences between groups at both 6 and 12 weeks in term of maximum and average pronation strengths, range of motion, Quick-Dash score, or Mayo-Wrist-Score. A greater reduction of pain was found with muscle repair at 6 weeks, but no significant difference was noted at 12 weeks.