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
Ossification of humerus Ossification of humerus The humerus is ossified from "eight" centers, one for each of the following parts: the body, the head, the greater tubercle, the lesser tubercle, the capitulum, the trochlea, and one for each epicondyle. One primary and seven secondary centres . The center for the body appears near the middle of the diaphysis in the eighth week of fetal life, and soon extends toward the extremities. This is the primary centre At birth the humerus is ossified in nearly its whole length, only the extremities remaining cartilaginous. During the first year, sometimes before birth, ossification commences in the