THE INTERNAL TOPOGRAPHY OF THE AXILLARY NERVE - AN ANATOMIC AND HISTOLOGIC-STUDY AS IT RELATES TO MICROSURGERY

The topography of the fascicular groups of the axillary nerve througho ut its course from the posterior cord until its passage through the qu adrangular space was studied in dissections of 40 brachial plexuses un der x3.5 toupe magnification. Additionally, 10 axillary nerves were ex cised in tote, and histologic serial sections were done to define fasc icular arrangement. In all specimens, the motor fascicular group for t he deltoid muscle was located most superiorly at the level of the quad rangular space. This motor portion could be identified as a distinct e ntity, up to 45 mm proximal to this level. In surgical treatment of ax illary nerve repair, one should direct special attention to the correc t identification, matching, and alignment of this motor fascicle, to a void wasteful regeneration of axons into the functionally unrelated fa scicles to the teres minor and the lateral shoulder skin.