The humerus is located between the shoulder and elbow joints of the upper extremity and is divided into the body of the humerus and the two ends of the humerus. The upper end of the humerus is the rounded humeral head, which forms the glenohumeral joint with the articular glenoid of the scapula. The ring around the head is called the anatomic neck and is also surrounded by two distinct elevations, the greater tuberosity and the lesser tuberosity, which is the stopping point of the supraspinatus tendon. The junction of the upper humerus and the body is the surgical neck, which is prone to humeral surgical neck fractures. The upper part of the body of the humerus is cylindrical, while the lower part is trigonous, and the junction of the two is locally weak in bone strength, which is also prone to fracture. The distal humerus forms the elbow joint with the radius and ulna, and the radial nerve and deep brachial artery pass behind the middle humerus; if the middle humerus is fractured, the radial nerve may be damaged.