The bony anatomy of the proximal humerus consists of the shaft, the head, and the greater and lesser tuberosities, which are separated by the bicipital groove (Fig. 6-1).
The articular surface of the head and the greater tuberosity are separated by a sulcus, where the insertions of the infraspinatus and supraspinatus tendons begin (Fig. 6-2).
The proximal humerus articulates with the glenoid and is partially covered by the acromion. The acromion overlies the posterior portion of the humeral head, and a significant portion of the humeral head is anterior to the acromion.
The head is retroverted from the shaft, generally around 30 degrees.
The humeral shaft has a posterior bow.
The medullary canal of the humerus tapers and ends several centimeters proximal to the olecranon fossa.
AP View Humerus
The AP view is obtained with the arm in neutral rotation. There is a tendency to get internally rotated views, with the forearm on the abdomen, and often the arm needs to be held for proper positioning (Fig. 6-3).
AP of the entire arm is helpful in determining deformity as well as fracture pattern (Fig. 6-4).
Postoperative x-rays are easier to obtain, with an intact limb.
Lateral View Humerus
Lateral view of the entire humerus can be difficult to obtain in case of fracture.
Lateral of the proximal humerus can be obtained with axillary lateral of the shoulder or as a transscapular Y view.
Caudal portion best obtained as cross-table lateral with arm held in neutral (Fig. 6-5).
Postoperatively, a single view can be obtained.
AP View Shoulder
Intraoperatively, the C-arm is used to get a true AP of the proximal humerus (Fig. 6-6).
A proper AP shows the sulcus between the lateral head and greater tuberosity at its deepest profile.
Note that the starting point is medial to the sulcus and anterior to the acromion.