Radial head stabilization after ulnar lengthening in type IVB multiple hereditary exostoses: a pediatric case report using a limb reconstruction system and fixation button

Introduction: Multiple Hereditary Exostoses (MHE) is a genetic disorder causing multiple osteochondromas, often affecting the forearm and leading to ulnar shortening and radial head dislocation. Surgical management in children is challenging, especially in achieving stable reduction. Case presentation: An 8-year-old girl with a 3-year history of left elbow deformity and restricted motion who underwent gradual ulnar lengthening at a rate of 0.25 mm/6 hours, achieving a total distraction of 3 cm with overlengthening by 1 cm, followed by stabilization using a fixation button technique to allow spontaneous radial head reduction, ensuring stable alignment without the need for open reduction. At three months, the patient achieved full, pain-free motion of the elbow and forearm, with no re-dislocation observed. Importantly, no perioperative complications, including pin site infection or neurovascular compromise, were encountered throughout the healing process. Clinical discussion: Combined ulnar lengthening and fixation button stabilization effectively maintained radial head reduction and improved early functional outcomes. Conclusion: This case highlights a novel application of fixation button fixation following gradual ulnar lengthening to prevent radial head re-dislocation in a pediatric patient with MHE Type IIB. This approach successfully restored joint alignment and function, offering a potential surgical option in similar complex cases.