<P> It is much more frequently fractured than the anatomical neck of the humerus . A fracture in this area is most likely to cause damage to the axillary nerve and posterior circumflex humeral artery . Damage to the axillary nerve affects function of the teres minor and deltoid muscles , resulting in loss of abduction of arm ( from 15 - 90 degrees ) , weak flexion , extension , and rotation of shoulder as well as loss of sensation of the skin over a small part of the lateral shoulder . </P>
clinical implications of fracture of the surgical neck of the humerus
damage to the axillary nerve and posterior circumflex humeral artery