In a shoulder girdle radiograph, which anatomy is labeled E?

• A. Surgical neck
• B. Lesser tubercle
• C. Anatomic neck
• D. Greater tubercle

Answer: (C)

The part labeled is the anatomic neck. This is the circular boundary that marks where the humeral head ends and the tubercles begin, effectively separating the articular surface from the tuberosities. On a shoulder radiograph, you can identify it as the smooth rim immediately beneath the head. The surgical neck lies a bit farther down, where the bone narrows toward the shaft, not at the edge of the joint surface. The greater and lesser tubercles are the prominent bumps on the proximal humerus—one on the lateral side, the other more anterior—and they sit away from that smooth ring. So the label sits at that articular-margin boundary, which is the anatomic neck.