Median nerve entrapment. Pronator teres syndrome. Surgical anatomy and correlation with symptom patterns.

The surgical anatomy of interest in the pronator teres syndrome was studied to shed light on the ramifying pattern of the median nerve, the number of its muscular branches and their branching levels and to pinpoint the location of the fibrous bands which may cause median nerve entrapment. The fibrous arch of the pronator teres muscle (pronator arch) was found to lie 3 cm to 7.5 cm below Hueter's line, that of the flexor digitorum superficialis muscle (superficialis arch), which is distal to the pronator arch, was found to lie 6.5 cm below Hueter's line in its most proximal position. Symptom patterns in terms of muscle weakness caused by median nerve entrapment at different levels were also evaluated.