Metal-on-metal bearings raise concerns about which systemic issue?

• A. Increased osteolysis
• B. Metallosis and systemic metal ion effects
• C. Ceramic fracture
• D. Squeaking

Answer: (B)

Metal-on-metal bearings raise concern because wear releases metal debris and ions into the body. The key issue is metallosis and systemic metal ion effects. Metallosis describes the local buildup of metal debris in periprosthetic soft tissues, which can cause inflammation, tissue damage, and loosening of the implant. In addition, circulating metal ions—primarily cobalt and chromium—can enter the bloodstream and potentially affect distant organs, leading systemic issues such as cardiotoxicity, neurotoxicity, thyroid and kidney effects. So the risk encompasses both local tissue reaction and systemic toxicity from metal ions. While osteolysis can occur locally due to debris, it’s not about systemic exposure; ceramic fracture and squeaking pertain to different wear mechanisms or mechanical symptoms rather than systemic metal toxicity.