Observation on the effect of reconstruction of the forearm rotation function with an external fixator in the treatment of congenital radioulnar synostosis

Abstract Purpose: To observe the effect of the forearm rotation function reconstruction with an external fixator in treating congenital radioulnar synostosis. Methods: From July 2017 to July 2023, 6 patients (9 sides) with congenital radioulnar synostosis who underwent reconstruction of the forearm rotation with the external fixator were retrospectively analyzed. The extent of flexion and rotation, the of Broberg and Morrey scores, and the grade according to the classification system proposed by Failla et al were compared before and after the operation. Results: All patients were followed up for an average of 12.00(8.00,38.50) months. The average range of rotation, the scores of Broberg and Morrey increased from 0°, 84.89 ±2.03 points to 83.22°±25.37°, 92.67 ± 1.66 points, respectively. The differences were statistically significant (t = 9.72, P < 0.01, t = 19.42, P < 0.01). There was no significant difference in forearm flexion before and after the operation ( Z = 1.34, P = 0.18 ). According to the Failla classification system, 2 forearms were classified as poor preoperatively, 6 as fair and 1 as good. Two forearms were assessed as excellent, 6 as good and 1 as fair during the last follow-up. Conclusion: Reconstruction of the forearm rotation function with an external fixator is safe and effective for treating congenital radioulnar synostosis. This technique can restore the partial rotational function of the forearm.