Possible anatomic structures causing entrapment neuropathies of the median nerve: an anatomic study

This study aimed at identifying the anatomic structures which may be responsible for entrapment neuropathies of the median nerve. Thirty upper extremities of 15 formalin fixed adult cadavers were dissected from the axilla to the distal forearm under Zeiss Opmi 9--FC microscope. We encountered seven different anatomic structures that may compress the median nerve. These structures are the brachialis muscle, Struther's ligament, the bicipital aponeurosis, pronator teres, flexor digitorum superficialis, the accessory head of plexor pollicis longus (Gantzer's muscle) and vascular structures. The supracondylar process, which we did not encounter in our dissection, has been reported as another cause. Based on our dissection findings and on literature, the median nerve can be compressed by seven different structures from the axilla to the distal forearm. Knowledge of the course of the median nerve and its relations with the adjacent anatomic structures facilitates determination of the exact cause of entrapment and allows for a safe surgery.