The influence of acetabular cup angle on the wear of "BIOLOX Forte" alumina ceramic bearing couples in a hip joint simulator.

The wear of "Biolox Forte" alumina ceramic bearing couples has been investigated at two different acetabular cup angles in a physiological hip joint simulator. All cups were set in the anatomical position of 45 degrees inclination in the M/L plane for the first two million cycles and then four of the six cups were re-aligned to 60 degrees for a further three million cycles. A "running-in" wear of 0.14 mm3 per million cycles was observed for the first million cycles, after which a steady state wear rate of 0.05 mm3 per million cycles was observed. Increasing the acetabular cup angle to 60 degrees did not significantly affect the wear rate.