Abstracts Posters SICOT-SOF meeting Gothenburg 2010 _2_

Poster
Topic: Biomaterials
Abstract number: 23687
INFLUENCE OF DIFFERENT COCRMO COUNTERFACES ON UHMWPE WEAR
FOR ARTIFICIAL JOINTS
Ana TORRES 1 , Mariano FERNANDEZ-FAIREN 2 , Vanesa GONZALEZ-MORA 2 , M
HOFFMANN 3 , R. STROOJNISDER 3 , F.J. GIL 3 , Antonio MURCIA 1
1 Hospital de Cabueñes, Gijon (SPAIN), 2 Instituto de Traumatologia y Ortopedia,
Barcelona (SPAIN), 3 Institute for Health and Consumer Protection. Joint Research
Centre, European Commision, Ispra (SPAIN)
The objective in these wear tests was to study the effect of different material
counterfaces on the UHMWPE wear behaviour. The materials used as counterfaces
were based on CoCrMo: forged with hand polished and mass finished, CoCrMo cast
and mass finished and additionally two coatings were proposed. The reciprocating
pin-on-flat (RPOF) device pin-on-disk wear was used for this study. RESULTS:
However, it is more interesting to compare the wear rates of the sliding couples than
to compare the volumetric wear after the one million cycles of the wear test. The
results show that the CoCrMo coating causes the highest UHMWPE wear of all
counterfaces tested. The CoCrMo coating wear rates in an order of magnitude higher
than that produced by the mass finished (forged) alloy, which in this study causes the
least UHMWPE wear. It is interesting to note that different surface treatments (mass
finishing and hand polishing) on the forged CoCrMo alloys lead to a significant
difference in UHMWPE wear. DISCUSION: The mass finished (forged) alloy causes
less UHWPE wear than the mass finished (cast) alloy and the later causes less
UHMWPE wear than the hand polished (forged) alloy. Mass finished (forged)
CoCrMo alloy is harder than the mass finished (cast) alloy and the latter is harder
than the hand polished (forged) alloy. CONCLUSION: Regarding the CoCrMo
coating, it has the highest hardness value, the coating has a very good scratch
resistance. Furthermore, coating fragments may have favour third body wear
mechanisms, roughening too the coating surface
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