An implantable endoprosthesis is adapted to articulate with one or more prosthesis surfaces, and is at least partially formed from a material having high wear resistance, which may be a polymeric material such as ultra-high molecular weight polyethylene (UHMWPE), polyetherether ketone (PEEK), and the like, or a metallic material, such as a cobalt-chrome alloy, or a ceramic material, such as alumina or zirconia. The body member of the endoprosthesis may be formed from a composite material, and includes at least a first component formed from a first material having increased wear resistance as compared to that of a second material forming a second component of the body member. The second material is generally more resilient as compared to the first material.