Test1 was run with three similar 52 mm diameter Metasul (Protasul-21WF,wrought-forged, high-carbon CoCr alloy, ISO5832-12) metal-on-metal bearings with a diametral clearance of 0.16 mm. They were manufactured in the early 2000s by Centerpulse Orthopaedics Ltd. (Switzerland). The type of cup was Durom, introduced in 2001,and it was sub-hemispherical(165°). The cup in clination angle in the test was70° (abduction 66°, anteversion 32°, Fig. 1). According to the definitions by Murray [18], these three angles corresponded to the anatomical inclination, operative inclination, and operative anteversion, respectively.