The radial head is the proximal articular surface of the radius and prone to dislocation in childhood and fracture in adults. It is palpable on the lateral side of the elbow, immediately distal to the lateral epicondyle of the humerus.
At the proximal radioulnar joint, the radial head sits in the radial notch of the proximal ulna and is held in place by the annular ligaments. At the radiohumeral joint, the radial head sits adjacent to the capitellum.
Assessment of radial head location is performed using the radiocapitellar line to ensure that the radial head and the capitellum are in line on all views.