Figure 3: Proximal (a) and distal (b) surface of specimen 3 after 5 million cycles of highly demanding activities. (a) Worn areas on the proximal surface are framed; arrows indicate the region where striated patterns occurred. (b) The framed areas on the distal surface displayed a colour change and the machining marks disappeared. (c) Worn area on the dorsal lateral bearing with a polished transition between the machining marks and the striated patterns; region is indicated by the arrows in picture (a). (d) Magnification from (c) with striated patterns; scaling is 1 mm in all pictures.