In vitro comparison of hip wear of marathon and durasul using both 32 and 38-mm head diametersy

The wear resistance of UHMWPE increases with the radiation dose up to approximately 10 Mrad. Certain more highly crosslinked polyethylenes have been approved by the FDA for use with head sizes larger than 32 mm in THR. Durasul is treated with 9.5 Mrad and Marathon with 5 Mrad of radiation. The aim of this study was to compare the wear rates in hip simulator of these two materials articulating with 32 and 38-mm chrome cobalt femoral head. The hypothesis was that the higher radiation dose would lead to a greater wear resistance for the 10 Mrad e-beam material. A new control was also introduced, a motion soak control. Marathon had greater wear against both 32 and 38 mm heads. The 38 mm head wore into Marathon 3.8 mg/million cycles when corrected with the motion soak control. Wear was not detectable in either series of Durasul simulator studies.