Irreducible isolated dislocation of the radial head.

Isolated dislocation of the radial head in adults is a rare injury. A 20-year-old man received a direct blow to his elbow and sustained an isolated anterior dislocation of the radial head. Open reduction was required because soft tissue interposition prevented reduction by closed manipulation. At operation the annular ligament was found to be ruptured and interposed between the articular surfaces, preventing reduction. A satisfactory result was obtained 1 year after surgery.