Generalized Size and Shape Description of UHMWPE Wear Debris — A Comparison of Cross-Linked, Enhanced Fused, and Standard Polyethylene Particles

Metallic and ceramic counterfaces with artificial surface textures were rubbed against ultra high molecular weight polyethylene (UHMWPE) pins in water-lubricated wear tests and the characteristics of wear debris were studied. Two types of surface textures were utilized. In the first type, an array of wedge shaped features was created on silicon wafers by microfabrication. It was found that the mean size of UHMWPE wear particles strongly depended on the length of the cutting edge of the wedge. For instance, for wedges with a cutting edge length of 55 μm, 15 μm, and 7 μm, it was found that more than 75% of wear particles had a mean length of 30–60 μm, 6–15 μm, and 4–10 μm, respectively. In the second type of textured surfaces, unidirectional patterns were created on the stainless steel discs. These unidirectional patterns consisted of long, parallel edges and grooves and were created by abrading the discs by different grits of sand papers. The length of the majority of unidirectional edges was found to be approximately equal to the dominant size of elongated wear debris. The narrowly distributed wear debris produced in this investigation can be used in the biological study of the effects of size and shape of UHMWPE wear particles in total joint replacements on osteolysis.

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Detailed three-dimensional size and shape characterisation of UHMWPE wear debris

Wear ◽

10.1016/j.wear.2010.12.005 ◽

2011 ◽

Vol 270 (7-8) ◽

pp. 455-463 ◽

Cited By ~ 14

Author(s):

Laura G. Gladkis ◽

Heiko Timmers ◽

Jennie M. Scarvell ◽

Paul N. Smith

Keyword(s):

Wear Debris ◽

Three Dimensional ◽

Size And Shape ◽

Uhmwpe Wear

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Bio-Ferrography to Capture and Separate Polyethylene Wear Debris from Hip Simulator Fluid and Compared with Conventional Filter Method

Journal of Tribology ◽

10.1115/1.2162554 ◽

2005 ◽

Vol 128 (2) ◽

pp. 436-441 ◽

Cited By ~ 12

Author(s):

Donna M. Meyer ◽

Adam Tillinghast ◽

Nevan C. Hanumara ◽

Ana Franco

Keyword(s):

Experimental Method ◽

Bovine Serum ◽

Wear Debris ◽

Polyethylene Wear ◽

Ultrahigh Molecular Weight Polyethylene ◽

Filter Method ◽

Acetabular Cup ◽

Serum Samples ◽

Uhmwpe Wear ◽

Uhmwpe Particle

This paper describes an experimental method, bio-ferrography, to separate ultrahigh molecular weight polyethylene (UHMWPE) wear debris, generated in hip simulators, from bovine serum lubricating fluid. A total of 54 experiments were performed in which an enzyme digestion “cocktail” was developed and used to clean the bovine serum samples of extraneous sugars, proteins, and lipids that interfere with the UHMWPE particle separation. Erbium chloride was used to marginally magnetize particles in the fluid prior to passing through the ferrographic device. The particles were captured and separated from the fluid by traversing the treated serum across a magnetic gap of a bio-ferrograph. Morphology of the captured and separated wear debris was compared with particles from samples of fluid filtered through a paper sieve arrangement with pores of 0.05micrometers in diameter. The UHMWPE wear debris collected using the described experimental method, were found to be between 0.1 and 20micrometers in diameter with spherical and pill-shaped particles. The filtered UHMWPE particles were in the same size range as the debris separated using bio-ferrography. To show that the experimental method captured UHMWPE particles, the spectra of the chemical composition of UHMWPE from an acetabular cup insert of a hip implant and of UHMWPE particles separated using bio-ferrography were compared and found to be the same. To further demonstrate that polyethylene could be captured and separated through the experimental method, manufactured polyethylene microspheres in the diameter range of 3-45micrometers, were captured and separated using the bio-ferrographic process.

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Investigating UHMWPE wear mechanisms by decomposing wear debris distributions

Wear ◽

10.1016/j.wear.2010.11.037 ◽

2011 ◽

Vol 271 (9-10) ◽

pp. 2208-2212 ◽

Cited By ~ 7

Author(s):

K. Plumlee ◽

C.J. Schwartz

Keyword(s):

Wear Mechanisms ◽

Wear Debris ◽

Uhmwpe Wear

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Ultra-High Molecular Weight Polyethylene Wear Debris Generated in Vivo and in Laboratory Tests; the Influence of Counterface Roughness

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1243/pime_proc_1996_210_385_02 ◽

1996 ◽

Vol 210 (1) ◽

pp. 3-10 ◽

Cited By ~ 47

Author(s):

J L Hailey ◽

E Ingham ◽

M Stone ◽

B M Wroblewski ◽

J Fisher

Keyword(s):

Molecular Weight ◽

High Molecular Weight ◽

Wear Debris ◽

Laboratory Tests ◽

Polyethylene Wear ◽

Uhmwpe Wear ◽

Major Variable ◽

Ultra High Molecular Weight ◽

Counterface Roughness

The objective of this study was to investigate the effect of counterface roughness and lubricant on the morphology of ultra-high molecular weight polyethylene (UHMWPE) wear debris generated in laboratory wear tests, and to compare this with debris isolated from explanted tissue. Laboratory tests used UHMWPE pins sliding against stainless steel counterfaces. Both water and serum lubricants were used in conjunction with rough and smooth counterfaces. The lubricants and tissue from revision hip surgery were processed to digest the proteins and permit filtration. This involved denaturing the proteins with potassium hydroxide (KOH), sedimentation of any remaining proteins, and further digestion of these proteins with chromic acid. All fractions were then passed through a 0.2 μm membrane, and the debris examined using scanning electron microscopy. The laboratory studies showed that the major variable influencing debris morphology was counterface roughness. The rougher counter-faces produced larger numbers of smaller particles, with a size range extending below 1 μm. For smooth counterfaces there were fewer of these small particles, and evidence of larger platelets, greater than 10 μm in diameter. Analysis of the debris from explanted tissues showed a wide variation in the particle size distribution, ranging from below 1 μm up to several millimetres in size. Of major clinical significance in relation to osteolysis and loosening is roughening of the femoral components, which may lead to greater numbers of the sub-micron-sized particles.

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