All radiographs show synostosis of the
proximal radioulnar joint (solid arrows in (a) and (b)) and fracture deformity from the previously healed proximal radial fracture.
The annular ligament secures the proximal radioulnar joint. Injury to the lateral UCL results in posterolateral rotatory instability of the elbow.
Axial scans provide a good view of both the ulnotrochlear joint and the proximal radioulnar joint. A technetium bone scan turns positive before clinical manifestations of HO are usually apparent and before the plain film radiographs are positive for HO.
The annular ligament secures the
proximal radioulnar joint. The lateral collateral ligament complex provides static stability to varus stress, while the anconeus is thought to add some dynamic varus stability.
The elbow is a modified hinged joint composed of three distinct articulations: the radiocapitellar joint, the ulnohumeral joint, and the
proximal radioulnar joint. The configuration of the joints provide for much of the stability of the elbow against varus and valgus stress at the extremes of extension and flexion.
For management of patients with posttraumatic radiocapitellar or
proximal radioulnar joint dysfunction, interpositional arthroplasties using the anconeus muscle have been proposed.