Abstract
Although polyethylene wear particles have been implicated in osteolysis and implant loosening, this study is the first to test whether chemical eluates extracted from ultra-high molecular weight polyethylene (UHMWPE) could also be involved in this process. Eluates were prepared from UHMWPE bar stock and examined for their effects on 3H-thymidine incorporation by human foreskin fibroblasts grown in 96-well culture plates. Low concentrations of eluates stimulated 3H-thymidine uptake; whereas, high concentrations inhibited uptake in a dose-dependent manner. Maximum inhibition of proliferation for eluates (87 ± 0.03% inhibition, n = 45 paired wells) was greater than that observed for particles (54 ± 0.07% inhibition, n = 45 paired wells). Ethylene oxide sterilization of UHMWPE reduced 3H-thymidine uptake at low eluate concentrations relative to sterilization by gamma-irradiation. It was concluded that leachable eluates from UHMWPE implants contribute to the osteolytic process at the bone-implant interface.
