Surgical neck of the humerus Surgical neck of the humerus The surgical neck of the humerus is a constriction below the tubercles of the greater tubercle and lesser tubercle, and above the Deltoid Tuberosity. 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
Upper extremity of humerus is a narrow area distal to the tubercles that is a common site of fracture. It makes contact with the axillary nerve and the posterior humeral circumflex artery. Upper extremity of humerus The upper or proximal extremity of the humerus consists of the bone's large rounded head joined to the body by a constricted portion called the neck, and two eminences, the greater and lesser tubercles. The head ("caput humeri"), is nearly hemispherical in form. It is directed upward, medialward, and a little backward, and articulates with the glenoid cavity of the scapula to form the glenohumeral joint (shoulder joint).