One case was a 54-year-old woman who had secondary osteoarthritis in the left hip, which was replaced with a Harris Galante-type prosthesis without cement. After eighteen months, a revision arthroplasty was carried out because radiographs showed bone resorption and loosening.
Another case was a thirty-year-old female. The right hip with aseptic necrosis of femoral head was replaced with an English Conversion Head. After four years, radiographs showed that inner head was dislocated from outer head. It compelled us to carry out revision arthroplasty.
In both cases, intraoperative cultures were negative for infection. The soft tissues adjacent to the companents were dark. On histological examination, the metal particles of groundup debris were intra- or extracellular. They produced a marked mononuclear histiocytic response.