What anatomical feature provides stability for the glenoid poly in TSA procedures?

The anatomical feature that provides stability for the glenoid poly in total shoulder arthroplasty (TSA) procedures is the subchondral bone.

In TSA, the glenoid component is typically seated into the subchondral bone of the glenoid cavity, which is the layer of bone just beneath the cartilage. This subchondral bone offers a solid foundation and optimal fit for the prosthesis, which is crucial for the proper function and longevity of the implant. The stability provided by this bony structure helps to resist micromotion and wear of the glenoid component during shoulder movements, improving the overall outcomes of the surgery.

Other features such as the serratus muscle, scapula cartilage, and acromion process, while important to shoulder anatomy and function, do not directly provide the same level of structural support for the glenoid poly as the subchondral bone does. The design and placement of the glenoid component rely heavily on the integrity and condition of the subchondral bone to ensure that the joint functions properly and to minimize the risks of complications post-surgery.