Comparison of hip simulator wear of 2 different highly cross-linked ultra high molecular weight polyethylene acetabular components using both 32- and 38-mm femoral heads.
Much evidence suggests that ultra high molecular weight polyethylene (UHMWP) irradiated to 9.5 Mrad has lower wear than UHMWP given 5 Mrad. Curiously, highly cross-linked polyethylenes gain weight during hip simulator testing. We postulated that (a) UHMWP irradiated to 9.5 Mrad would wear less than UHMWP irradiated to 5 Mrad UHMWP, (b) articulation against 38-mm heads would accentuate this difference, and (c) weight gain of highly cross-linked material reflects the inadequacy of load soak controls. We compared 9.5 versus 5 Mrad polyethylene in hip simulator wear tests, with both load soak corrections and with novel "motion soak" corrections. The 9.5-Mrad material wore less than 5-Mrad material for 32- and 38-mm heads. Motion soak corrections were more accurate than load soak corrections.
Estok
Daniel M
DM
Harris Orthopaedic Biomechanics and Biomaterials Laboratory, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA.
Burroughs
Brian R
BR
Muratoglu
Orhun K
OK
Harris
William H
WH
D006622:Hip Prosthesis; D006801:Humans; D008970:Molecular Weight; D020959:Polyethylene; D011474:Prosthesis Design; D011475:Prosthesis Failure
D020959:Polyethylene