Radial tunnel syndrome.

Intermittent compression of the PIN within and just distal to the anatomic region known as the radial tunnel is responsible for a constellation of signs and symptoms known as radial tunnel syndrome. The five structures commonly implicated as possible offenders include the fibrous adhesions between the brachialis and brachioradialis, the leash of Henry, the fibrous edge of the ECRB, the arcade of Fröhse, and fibrous bands associated with the supinator muscle. The condition is dominated by pain centered over the radial tunnel, whereas muscle weakness, if present, is clinically insignificant. Specific attention to the character and point of maximal tenderness, worsening of pain on the provocative middle finger extension and resisted supination tests, and relief of symptoms following a radial tunnel anesthetic block help diagnose RTS. Electrodiagnostic testing presently has limited use in diagnosing RTS. The management of RTS includes activity modification and other conservative measures. Most patients, however, eventually require surgery, in which routine release of all potential constricting structures is performed. Although several surgical approaches are available, the brachioradialis-ERCL interval approach is one that has been very satisfying in our hands.