Early failure of modern metal-on-metal total hip arthroplasty using a Wagner standard cup.

In 54 patients (1 man and 53 women), 55 hips underwent primary metal-on-metal total hip arthroplasty (Metasul) with a Wagner standard cup (44-48 mm in outer diameter) and were followed for a minimum of 3 years. All patients received the same type of cementless femoral component (Natural Hip Stem) and femoral head (28 mm in diameter). Twelve (21.8%) of the 55 Wagner standard cups showed aseptic loosening over a mean period of 31 months postoperatively, and there were no bone anchors on the outer surface of the 9 retrieved cups. From our experience, the small Wagner standard cup does not achieve sufficient osteointegration and we do not recommend use of this cup, especially for dysplastic hips.