Why would a CA Humeral head be indicated instead of a Univers Revers Total Shoulder Arthroplasty?

• A. Intact Rotator Cuff
• B. Severe glenoid bone loss
• C. Massive rotator cuff tear
• D. Glenoid bone loss with cuff tear

Answer: (A)

The main idea here is that the decision between an anatomic humeral head prosthesis and a reverse total shoulder hinges on the rotator cuff’s status. If the rotator cuff is intact, the normal ball-and-socket mechanics can be restored with an anatomic or CA humeral head, so this option is the best choice. When the rotator cuff is healthy, the joint can be centered and moved normally, allowing the native glenoid–humeral articulation to function with anatomic components.

In contrast, when there is a massive rotator cuff tear or a cuff tear with glenoid deficiency, the normal mechanics are lost and a reverse design is needed. The reverse changes the center of rotation and relies on the deltoid to lift the arm, which compensates for the deficient cuff. Severe glenoid bone loss adds complexity to placing anatomic components, and with cuff deficiency these cases are typically approached with a reverse.

So, intact rotator cuff fits the indication for a CA humeral head because it supports restoring natural anatomy, whereas the other scenarios involve cuff deficiency (or substantial glenoid issues with cuff loss) where a reverse construct is favored.