The foreign body reaction in total hip arthroplasties. A correlated light-microscopy, SEM, and TEM study.

An in vivo histological and ultrastructural study of the cellular reaction to particulate material currently used in orthopaedic surgery produced evidence that, on a strictly cellular level, the main damage is done by the smallest particles produced by hip prostheses, i.e. metal particles, irrespective of differences in their chemical composition. Particle size and release rate are the critical factors, although other mechanisms of cellular damage may be active once granulation tissue is formed.