Comparison of the response of primary human blood monocytes and the U937 human monocytic cell line to two different sizes of alumina ceramic particles.

It is well recognized that wear particles derived from orthopaedic implants have the potential to induce inflammation, which may eventually lead to aseptic loosening of the artificial joint. We hypothesized that alumina ceramic particles of different sizes cause a differential cytokine response by human monocytes. To test this hypothesis a human monocytic cell line (U937) and primary human blood monocytes obtained from healthy volunteers were exposed to ceramic particles within the range known to be generated in vivo.