Volar Stabilization of the Distal Radioulnar Joint for Chronic Instability Using the Pronator Quadratus

In cases of chronic distal radioulnar joint (DRUJ) instability without DRUJ arthritis, reconstruction of the mechanical integrity of the radioulnar ligaments of the triangular fibrocartilage complex has been considered an ideal surgical treatment. However, reconstructive methods have several disadvantages. We evaluated volar stabilization of the DRUJ for chronic instability using the pronator quadratus (PQ) to determine whether it provided (1) proper stability, (2) restored wrist function, (3) was relatively convenient, and (4) was associated with a low complication rate. Altogether, 21 patients with chronic DRUJ instability (12 men, 9 women) with a mean age of 34 years (range, 17-65 years) were enrolled in the study. The diagnostic criteria were as follows: 3 months after the injury, greater than 8 mm of palmar-dorsal translation of the ulna relative to the radius, there was a lack of clear end point resistance compared with the contralateral side, and nonstressed computed tomographic scans provided supporting evidence. Follow-up was at least 12 months (range, 12-38 months). Palmar-dorsal translation of the ulna relative to the radius was decreased significantly from 10 to 4 mm (P = 0.028) and epicenter was increased significantly at the last follow-up [P = 0.015/0.026 (70 degrees of supination/neutral, respectively)]. Wrist range of motion was not significantly different, but grip strength had increased from 72% to 91%. Disabilities of the arm, shoulder, and hand and patient-rated wrist evaluation were also decreased compared with preoperative measurements [34.4 to 12.5/42.7 to 14.7 (disabilities of the arm, shoulder, and hand/patient-rated wrist evaluation, respectively)]. Pronator quadratus advancement volar stabilization provided proper stability, restored wrist function, was relatively convenient, and was associated with few complications. Our experience indicates that it is an acceptable, effective treatment option to reverse DRUJ instability in patients who did not have advanced DRUJ arthritis.