The humeral head implant for Univers II and glenosphere for Univers Revers are composed of which material?

• A. Cobalt Chrome
• B. Stainless Steel
• C. Titanium Alloy
• D. Polymer

Answer: (A)

Choosing the right material for the articulating surfaces in shoulder implants hinges on wear resistance, hardness, and biocompatibility. For the Univers II humeral head and Univers Revers glenosphere, the standard material is a cobalt-chromium alloy. Its high hardness and excellent wear resistance keep the surface smooth against the polyethylene insert over many cycles of shoulder movement, which minimizes wear debris and extends implant life. It also resists corrosion in the body, contributing to long-term durability.

Stainless steel, while strong, is more prone to corrosion and generally offers lower wear performance for articulating surfaces, making it a less common choice here. Titanium alloys are favored for stems and baseplates because of their favorable modulus and osseointegration, but they do not match cobalt-chromium’s wear characteristics for the ball or glenosphere articulation. The polymer option refers to the polyethylene bearing, not the actual ball or glenosphere material. So the humeral head and glenosphere are designed from cobalt-chromium alloy.