The supinator muscle and radial nerve entrapment: historical note and modern anatomical insight

Due to its deep location, close to the elbow joint, the supinator muscle requires special dissection skills. This fact enhanced our interest for a more accurate knowledge of the anatomical relations of the muscle with the elbow joint and with the posterior branch of the radial nerve. There are many clinical consequences of these anatomic relations, such as epicondylar impingement syndromes. There resides an open field of research on the anatomical basis of radial nerve entrapment syndromes. In 1618, Da Cortona published a clear reference to the passage of the nerve in close relation to the deeper side of the supinator muscle. All the material here presented, corresponds to careful dissection work on embalmed corpses, prepared at our dissection lab, with original techniques. The classical approach through ventral dissection demonstrates the relation between the supinator muscle arcade (Frohse) and the radial nerve, with its natural sliding adipose cushion sheath. The dorso-lateral surgical approach, allows deep dissection of the forearm muscles, in relation to the lateral epicondylar bundle, and the elbow joint capsule. Stereoscopic microscopy completed our macroscopic observations. Future histological and microscopic analysis of the nature of the supinator arcade; of the intricate relation of the supinator muscle fibers and the capsular fibers of the elbow; and also, the importance of the vascular elements of the muscle arcade and of the adipose bursa that surrounds the radial nerve, will further provide rich interesting research towards the improvement of pathogenic knowledge of the regional impingement, and compressive radial nerve syndromes.