Pronator Quadratus Muscle Flap for Prevention of Flexor Tendon Rupture after Distal Radius Volar Plating.

Background: Flexor tendon rupture is a serious but rare complication that can occur after volar plating of distal radius fractures. This study aims to introduce a novel surgical technique that uses a pronator quadratus (PQ) muscle flap transposition to protect the flexor tendons from rupture or irritation and evaluate its outcomes. Methods: A retrospective review was conducted on 204 patients with unstable distal radius fractures who underwent a standard volar flexor carpi radialis approach with extended release of the PQ muscle during exposure. A PQ muscle flap was harvested and transposed over the distal edge of the plate after open reduction and internal fixation of the distal radius. Postoperatively, patients were evaluated for flexor tendon irritation and rupture. Patients who had this injury before the use of the PQ flap were compared with the patients who received the PQ flap. Results: Of the 204 patients, 119 received the PQ flap, and 85 did not. The mean follow-up time was 30.4 months. Among the patients who did not receive the PQ flap, five (5.9%) required plate removal or conservative treatment for tendon irritation or rupture. In contrast, only one patient (0.8%) who received the PQ flap required plate removal for flexor tendon irritation. Conclusions: The PQ muscle flap is a quick and effective surgical technique that reduces the risk of flexor tendon rupture or irritation during distal radius fracture fixation. The PQ muscle flap acts as a buffer between the plate and tendon and is more effective than not transposing the muscle.