Where does the glenoid poly gain fixation during shoulder arthroplasty?

In shoulder arthroplasty, particularly in Total Shoulder Arthroplasty (TSA), the glenoid poly, which is typically a polyethylene component, achieves fixation primarily in the glenoid vault. The glenoid vault consists of the surface of the scapula that articulates with the humeral head, making it the anatomical location designed for proper fit and stability of the glenoid component.

When the glenoid poly is implanted, it is secured to this part of the scapula, which is the proper location for load transfer during arm movement. The fixation of the glenoid poly in this area is crucial for the overall function of the shoulder joint, as it helps to replicate the natural biomechanics of the shoulder and maintain joint congruity during motion.

The other options, such as the humeral head, scapular spine, and clavicle, do not serve as fixation points for the glenoid poly. Instead, these structures have different roles in shoulder anatomy and function. The humeral head is the component of the upper arm bone that articulates with the glenoid, the scapular spine is a bony ridge providing muscle attachment, and the clavicle serves as a strut connecting the arm to the body but does not interface with the glenoid component