Extract
Metal-on-metal bearings have demonstrated low wear after many years in
vivo1,2.
Consequently, there has been a resurgence of interest in metal-on-metal
bearings. There are, however, concerns about potential adverse effects due to
local accumulation and systemic distribution of cobalt-chromium wear moieties
and ions, especially after several decades in
situ3-5.
Cobalt and chromium particles have been shown to induce carcinoma in animal
models6, giving rise
to the concern that such alloys could have the same effect in human tissue, if
present in sufficient amounts for a sufficient length of time.