PERFORMANCE OF THIN POLY LINERS UNDER HIGH CUP ANGLE AND NECK-LINER IMPINGEMENT TESTING

IntroductionModerately crosslinked, thermally treated ultrahigh molecular weight polyethylene (UHMWPE) has to date demonstrated a good balance of wear resistance and mechanical properties. MARATHON™ Polyethylene (DePuySynthes Joint Reconstruction, Warsaw, IN) is made from polyethylene resin GUR 1050, gamma-irradiated at a dose of 5.0 Mrads to create crosslinking of polyethylene, and followed by a remelting process to eliminate free radicals for oxidative stability. 10-year clinical study [1] and laboratory wear simulation tests [2–3] have reported excellent wear performance of the MARATHON poly.There continues to be demand for improved head-to-shell ratio acetabular systems because larger head sizes have the benefits of increased stability and range of motion. The increased head-to-shell ratio is often times achieved by using a reduced liner thickness. One of the clinical concerns of thinner poly liners is the potential for rim fracture, particularly in the occurrences of rim loading or impingement at hig...