At 10 years there was significantly less wear of HXLPE ( 0.003 mm/year ; 95 % confidence interval [ CI ] , 0.010 ; SD 0.023 ; range , -0.057 to 0.074 ) compared with UHMWPE ( 0.030 mm/year ; 95 % CI , 0.012 ; p < 0.001 ; SD 0.0.27 ; range , -0.001 to 0.164 ) .