Which of the following factors influences the choice between a stemmed and stemless shoulder prosthesis?

• A. Bone quality
• B. Weather
• C. Patient age
• D. Implant price

Answer: (D)

The main factor is the quality of the proximal humeral bone. Stemless designs rely on secure fixation in the metaphyseal bone, so when the metaphysis has good bone stock and strength, a stemless component can achieve stable fixation and preserve bone for potential future revisions. If the proximal bone is osteoporotic, deficient, or there is significant bone loss, a stemmed design provides a more reliable fixation by engaging the humeral canal (diaphyseal fixation), reducing the risk of loosening or micromotion.

Weather has no bearing on prosthesis selection, and while age can correlate with bone quality, the actual bone stock matters more for deciding between stemmed and stemless. Price can influence overall decisions in a broader sense, but it does not determine the biomechanical suitability of the fixation method.