DOI: https://doi.org/10.36347/sjmcr.2025.v13i10.020

Pages: 2270-2274

Introduction: Post-traumatic radioulnar synostosis is a rare complication with disabling consequences for prognostic function. Several factors predictive of its occurrence should be taken into account when managing a fracture of the two bones of the forearm. We report a case of radioulnar synostosis complicating a complex open fracture of both forearm bones. The aim is to identify factors favouring the occurrence of synostosis after osteosynthesis of the two bones of the forearm. Case report: A 55-year-old female patient with no significant medical history, presenting with a complex open fracture of both forearm bones treated with intramedullary nailing, with postoperative radiography showing several bone fragments filling the interosseous membrane opposite the fracture sites. During the procedure, she developed radioulnar synostosis with repercussions on prono-supination function, which required surgery. The surgical procedure was performed under right supraclavicular block. The lesion was approached via a posterolateral approach of the forearm, and exploration revealed a significant bone bridge between the ulna and radius. A large bone fragment was excised using osteotomes, followed by curettage of the bone resection edges. No fibrous tissue was interposed between the resection borders. At the 12-month follow-up, there was good recovery of prono-supination function with no recurrence on follow-up X-rays. Conclusion: Post-traumatic radioulnar synostosis remains a complication with serious consequences for forearm function. Complex fractures with fragments in the interosseous limb, before or after surgery, are a risk factor for synostosis.