Why may implant loosening occur post-TSA?

Implant loosening after Total Shoulder Arthroplasty (TSA) is often attributed to inadequate surgical technique or poor component fit. The surgical technique plays a crucial role in the initial fixation of the implant. If the components are not positioned correctly or if the bone preparation is inadequate, it can result in an unstable interface between the implant and the bone, leading to loosening over time. A proper fit is essential for optimal load distribution and stability, and any mismatch can increase the risk of micromotion, which contributes to osteolysis and eventual loosening.

Other factors, such as physical therapy intensity, patient compliance with follow-ups, and the weight of the prosthesis, are less directly related to the structural integrity and fixation of the implant within the bone. While inappropriate physical therapy may put undue stress on the shoulder, it is not a primary cause of implant loosening compared to the foundational issues related to surgical precision and component fitting. Similarly, while follow-up care is important for monitoring and addressing issues, forgetting follow-ups does not inherently cause loosening; it may just lead to a lack of timely intervention. Lastly, the weight of the prosthesis is typically designed with the anatomical and functional concerns in mind, meaning it is less likely to negatively affect