Analysis of corrosion in stainless steel total hip prostheses

Extensive corrosion was observed in a series of twenty stainless steel (SS) femoral hip prostheses (T-28 design, Zimmer Inc.), retrieved between 8 and 20 years after implantation (avg 14 y.) because of aseptic loosening and stem fracture. Corrosion appeared exclusively inferior to the stem collar, and covered, on average, 16% of the stem surface. The corrosion product was compositionally heterogeneous, and contained Fe, Ni, and Cr, as well as nonmetallic elements such as Ca, K, and Cl. The location and morphology of the corrosive damage are indicative of fretting and crevice corrosion. Despite the severity of the observed corrosive damage, each of these stems experienced a long service life