The volumetric penetration from 1 to 10 years for the UHMWPE group was 98 mm3 ( 95 % CI , 46 mm3 ; SD 102 mm3 ; range , -4 to 430 mm3 ) compared with 14 mm3 ( 95 % CI , 40 mm3 ; SD 91 mm3 ; range , -189 to 242 mm3 ) for the HXLPE group ( p = 0.01 ) .