1. Fracture of the capitellum itself is very rare and is produced by a fall or blow on a slightly flexed or extended elbow in such a way that the head of the radius locks with the capitellum, splitting it from its attachment to the humerus.
2. The diagnosis is determined by a history of injury to the elbow with limitation of motion out of all proportion to the physical signs of injury. There is no disturbance of the elbow landmarks. Crepitation and the palpation of a fragment in the fossa can usually be made out. The x-ray, especially the lateral view, demonstrates the fracture line and the usual upward and forward displacement of the fragment.
3. The best treatment is extirpation of the fragment. No attempt should be made to treat such cases conservatively, as the results are almost always disabling, while in those cases treated surgically excellent results are obtained.