Abstract: BACKGROUND: In the past, it was necessary to cut off the pronator quadratus muscle in the treatment of distal radius fractures. Failure to repair the pronator quadratus muscle can lead to a series of complications.  
OBJECTIVE: To explore the clinical efficacy of different methods of preserving the pronator quadratus muscle combined with a palmar steel plate in the treatment of distal radius fractures.
METHODS: Clinical data of 66 patients with distal radius fractures were retrospectively included, divided into the traditional Henry approach group (group A), the split brachioradialis tendon approach group (group B), and the posterior pronator quadratus muscle approach group (group C), with 22 patients in each group. Postoperative internal fixation, fracture healing, and postoperative complications were observed in the three groups. The visual analog scale score of postoperative wrist pain and forearm rotation angle were compared among the three groups. The Dienst Joint Scale was used to evaluate the wrist function of patients.
RESULTS AND CONCLUSION: (1) The surgical time, intraoperative blood loss, and fracture healing time of groups B and C were significantly lower than those of group A (P < 0.01). There was no significant difference in intraoperative blood loss and fracture healing time between groups B and C, but the surgical time was shorter in group B. (2) The anteroposterior and lateral wrist X-ray examination 3 days and 1 and 3 months after surgery exhibited that there were no significant differences in radial height, palm angle, and ulnar deviation angle among the three groups (P > 0.05). No significant difference was detected in various indicators during the same phase among the three groups (P > 0.05). (3) At a follow-up of 12 months after surgery, there were no significant differences in visual analog scale scores and forearm rotation angle among the three groups. However, the evaluation results at 1 and 3 months after surgery demonstrated significant differences in visual analog scale scores and forearm rotation angle among the three groups (P < 0.05). Among them, group C had a lower visual analog scale score and a larger forearm rotation angle. (4) According to the Dienst joint scoring standard, the excellent and good rate of wrist joint function evaluation was 86%(19/22), 91%(20/22), and 95%(21/22) in groups A, B, and C, respectively 12 months after surgery. (5) All patients did not experience any postoperative vascular or neurological damage or surgical site infection. Group A had three cases of tendon irritation, two cases of traumatic arthritis, and two cases of carpal tunnel syndrome. In group B, tendon irritation occurred in 1 case and joint stiffness in 1 case. There was 1 case of traumatic arthritis and 1 case of carpal tunnel syndrome in group C. (6) It is suggested that different surgical methods for treating distal radius fractures have achieved good clinical results. Placing a steel plate under the pronator muscle can alleviate early postoperative pain, promote early activity, and restore normal life. The brachioradialis tendon approach has more advantages in exposing intraoperative fractures and can shorten the surgical time.

Key words: distal radius fracture, Henry’s approach, pronator quadratus muscle, palmar steel plate, internal fixation