In fractures of the elbow with an associated fracture of the coronoid process, the size of the coronoid fragment determines the stability of the joint. A diminution of the arch of the incisura semilunaris by about 30 degrees causes instability of the elbow. We present an alternative way of treating the special case of a fracture of the coronoid process combined with comminuted fracture of the proximal end of the radius. A suitable fragment of the head of the radius is used to reconstruct the coronoid process. The stability achieved allows early functional postoperative treatment with a good range of movement at the elbow joint.