Necrotic and inflammatory changes in metal-on-metal resurfacing hip arthroplasties

Abstract

Our findings indicate that there is a spectrum of necrotic and inflammatory changes in response to the deposition of cobalt-chrome (Co-Cr) wear particles in periprosthetic tissues. Areas of extensive coagulative necrosis and a macrophage and T lymphocyte response occur in implant failure and pseudotumors, in which there is also granuloma formation. The pathogenesis of these changes is uncertain but it may involve both a cytotoxic response and a delayed hypersensitivity (type IV) response to Co-Cr particles.