Congenital proximal radioulnar synostosis treated with derotational osteotomy: a pediatric case report from Ethiopia.

Introduction and importance: Congenital proximal radioulnar synostosis is a rare skeletal anomaly causing a fixed forearm position and significant functional disability. We present the first surgically treated case from Ethiopia, demonstrating the efficacy of derotational osteotomy. Case presentation: A 7-year-old boy presented with fixed pronation of the right forearm since birth, with difficulty feeding himself and writing properly. Radiographs confirmed Cleary-Omer Type IV synostosis. A derotational osteotomy at the synostosis site was performed with Kirschner-wire fixation and long-arm splint immobilization. Clinical discussion: At the final two-year follow-up, the forearm rested in neutral with a functional rotational arc from 10° of pronation to 60° of supination. The child performs all daily activities independently without compensatory shoulder movements. Conclusion: Derotational osteotomy with Kirschner-wire fixation proved effective and feasible for congenital proximal radioulnar synostosis, even in settings where advanced implants are unavailable.