An evaluation of the acetabular cartilage was performed grossly and histologically in a patient who had a bipolar hemiarthroploasty, which had served satisfactorily for 2 years until the femoral prosthetic head had been separated from the acetabular assembly due to creep deformation of the inner bearing polyethylene cup. This study indicates that the double-bearing bipolar prosthesis dose not necessarily have an advantage over the classical single-piece prosthesis in the prevention of acetabular cartilage wear.