Linked Life Data

10872774

Source:http://linkedlifedata.com/resource/pubmed/id/10872774

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
14
pubmed:dateCreated
2000-10-19
pubmed:abstractText
Ultra-high molecular weight polyethylene (UHMWPE) is known to degrade during natural (shelf) aging following gamma irradiation in air, but the mechanical signature of degradation remains poorly understood. Accelerated aging methods have been developed to reproduce the natural aging process as well as to precondition total joint replacement components prior to joint simulator wear testing. In this study, we compared the mechanical behavior of naturally (shelf) aged and accelerated aged tibial inserts using a previously validated miniature specimen testing technique known as the small punch test. Tibial inserts made-of GUR 1120 and sterilized with 25 to 40 kGy of gamma radiation (in air) in 1988, 1993, and 1997 were obtained; a subset of the 1997 implants were subjected to 4 weeks of accelerated aging in air at 80 degrees C. To determine the spatial variation of mechanical properties within each insert, miniature disk shaped specimens were machined from the surface and subsurface regions of the inserts. Analysis of variance of the test data showed that aging significantly affected the small punch test measures of elastic modulus, initial load, ultimate load, ultimate displacement, and work to failure. The accelerated aging protocol was unable to reproduce the spatial mechanical profile seen in shelf aged components, but it did mechanically degrade the surface of GUR 1120 tibial components to an extent comparable to that seen after 10 years of natural aging. Test specimens showed a fracture morphology consistent with the decreased ductility and toughness which was corroborated by the small punch test metrics of this study. Our data support the hypothesis that UHMWPE undergoes a spatially nonuniform change towards a less ductile (more brittle) mechanical behavior after gamma irradiation in air and shelf aging.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0142-9612
pubmed:author
pubmed:issnType
Print
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1451-60
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Degradation of mechanical behavior in UHMWPE after natural and accelerated aging.
pubmed:affiliation
Stryker Howmedica Osteonics, Allendale, NJ 07401, USA. edidin@warwick.net
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't