Median Nerve Disorders at the Elbow

Abstract

Median nerve compressive neuropathy at the elbow and proximal forearm occurs in predictable anatomic locations and with three distinct pathologic conditions: supracondylar process and ligament of Struthers, pronator tunnel syndrome, and anterior interosseous nerve compression syndrome. The supracondylar process arises from the medial aspect of the humerus, ca. 3–5 cm above the medial epicondyle. The ligament of Struthers prolongs it, inserting distally onto the medial epicondyle. This anomalous and congenital bone-ligament structure was noted by Struthers in 1848. The median nerve and the brachial artery pass behind the process, through the opening produced by the Struthers ligament when it is present. Pronator syndrome is an entrapment neuropathy of the median nerve in the anatomic area of the distal humerus and proximal forearm below the lacertus fibrosus or between the two heads of the pronator teres muscle and the fibrous arch of the sublimis muscle (flexor digitorum superficialis). Compression of the anterior interosseous nerve in the proximal forearm is a pure motor neuropathy, which results in weakness or paralysis of the flexor pollicis longus and flexor digitorum profundus to the index, combined with pronator quadratus involvement. Median nerve entrapment has been reported in sports requiring forceful repetitive forearm pronation or gripping such as baseball, racquet sports, weight lifting, and gymnastic as well as in contact sport or after an acute trauma to the proximal forearm.