The Supinator Channel Syndrome:Atraumatic Lesion of the Posterior Interosseus Branch of the Radial Nerve Case Reports

Abstract

The “supinator channel syndrome”, indicating a lesion of the most distal branch of the radial nerve, below the motor twigs to the radial hand extensors and the brachioradial muscle, within the supinator channel is characterized by 1) weakness or paralysis of finger extension at the metacarpophalangeal joints and of thumb extension at the interphalangeal joint, 2) no weakness of the hand extensors. Two cases of this syndrome in young women are reported. Exploration in one revealed an entrapment of the nerve by fibrous tissue at the entrance of the supinator channel. After division of the fibrous band, the patient made a quick recovery. In the other, conservatively treated case, full recovery was delayed for nearly 10 months. The value of electromyography for evaluating the topography of the lesion and incipient recovery is emphasized.