A
It anatomically restores the footprint of the rotator cuff insertion.
B
It decreases the moment arm of the anterior deltoid.
C
It lateralizes the center of rotation to increase capsular tension.
D
It medializes and distalizes the center of rotation, recruiting the deltoid to elevate the arm.
Explanation:Correct Option: D. The RTSA design medializes and distalizes the anatomical center of rotation of the glenohumeral joint. This significantly increases the moment arm and tension of the deltoid muscle, allowing it to act as the primary elevator of the arm in the absence of a functional rotator cuff. (Ref: Boileau et al., J Shoulder Elbow Surg, 2005)