A fracture of the neck of the radius when the head is not ossified can be difficult to assess and treat. In a four-year-old child we suspected from the radiographs that there was an O’Brien type-III injury after trauma. Partial manual reduction of the non-ossified radial head was completed using the Métaizeau technique of intramedullary Kirschner (K-) wiring aided by intraoperative arthrography. The child had a full range of movement at the elbow and wrist when reviewed 11 weeks after the injury, three weeks after removal of the K-wire. We suggest that intraoperative arthrography is a useful complement to the Métaizeau technique for successful reduction of fractures of the radial neck in the presence of a non-ossified radial head.