Effect of Lubricant Protein Concentration on the Wear of Ultra-High Molecular Weight Polyethylene Sliding Against a CoCr Counterface

2003 ◽  
Vol 125 (3) ◽  
pp. 638-642 ◽  
Author(s):  
Vesa Saikko
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Protein Concentration ◽  
Calf Serum ◽  
Wear Testing ◽  
Wear Factor ◽  
Prosthetic Joints ◽  
Uhmwpe Wear ◽  
Pin On Disk ◽  
Ultra High Molecular Weight

In the wear testing of prosthetic joints, the optimal lubricant protein concentration is disputed. The effect of protein concentration of calf serum based lubricant on the wear of ultra-high molecular weight polyethylene against CoCr was studied with a 12-station, circularly translating pin-on-disk device. The wear factor first steeply increased with increasing concentration, reached a peak at 10–20 mg/ml, and then slowly decreased. Below 20 mg/ml, the wear mechanisms were not entirely representative of clinical wear. Above this value, the morphology of the UHMWPE wear surface resembled that of retrieved cups. The results indicated that the concentration should not be below 20 mg/ml. The scope of this recommendation is discussed.

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

1996 ◽  
Vol 210 (1) ◽  
pp. 3-10 ◽  
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.

A Comparison of the Wear of Cross-Linked Polyethylene against Itself with the Wear of Ultra-High Molecular Weight Polyethylene against Itself

1996 ◽  
Vol 210 (4) ◽  
pp. 297-300 ◽  
Author(s):  
T J Joyce ◽  
A Unsworth
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Contact Stress ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Measurement Point ◽  
Wear Factor ◽  
Ultrahigh Molecular Weight ◽  
Ultra High Molecular Weight ◽  
Wear Tests

Wear tests were carried out on reciprocating pin-on-plate machines which had pins loaded at 10 N and 40 N. The materials tested were irradiated cross-linked polyethylene sliding against itself, irradiated ultra-high molecular weight polyethylene sliding against itself and non-irradiated ultra-high molecular weight polyethylene sliding against itself. After 153.5 km of sliding, the non-irradiated ultrahigh molecular weight polyethylene plates and pins showed mean wear factors under 10 N loads, or a nominal contact stress of 0.51 MPa, of 84.0 × 10−6 mm3/N m for the plates and 81.3 × 10−6 mm3/N m for the pins. Under 40 N loads, or a nominal contact stress of 2.04 MPa, the non-irradiated ultra-high molecular weight polyethylene pins sheared at 22.3 km. At the last measurement point prior to this failure, 19.1 km, wear factors of 158 × 10−6mm3/N m for the plates and 85.0 × 10−6 mm3/N m for the pins had been measured. After 152.8 km, the irradiated ultra-high molecular weight polyethylene plates and pins showed mean wear factors under 10 N loads of 59.8 × 10−6 mm3/N m for the plates and 31.1 × 10−6 mm3/N m for the pins. In contrast, after 150.2 km, a mean wear factor of 0.72 × 10−6 mm3/N m was found for the irradiated cross-linked polyethylene plates compared with 0.053 × 10−6 mm3/N m for the irradiated cross-linked polyethylene pins.

The Cooperative Effects of Protein and Lipid on Wear Behavior of Ultra-High Molecular Weight Polyethylene

2005 ◽  
Author(s):  
Y. Sawae ◽  
T. Murakami
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Lipid Content ◽  
Lipid Composition ◽  
Wear Behavior ◽  
Wear Test ◽  
Cooperative Effects ◽  
Uhmwpe Wear ◽  
Ultra High Molecular Weight ◽  
Wear Tests

The cooperative effects of protein and lipid on the wear behavior of ultra-high molecular weight polyethylene (UHMWPE) was examined in laboratory wear tests with a multidirectional sliding pin-on-plate wear tester. Results indicated that the protein and lipid composition of lubricant used in the wear test had substantial effects on the wear behavior of UHMWPE sliding against a metal counter face. Not only the amount of protein and lipid content but also a preparation procedure of the lubricant might affect the UHMWPE wear.

Biotribology Behavior of Ultra-High Molecular Weight Polyethylene against Carbon/Carbon Composites Used for Hip Joint Replacement

2011 ◽  
Vol 685 ◽  
pp. 327-330
Author(s):  
Lei Lei Zhang ◽  
He Jun Li ◽  
Ke Zhi Li ◽  
Ling Jun Guo ◽  
Wei Feng Cao ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Hip Joint ◽  
Wear Behavior ◽  
Calf Serum ◽  
Wear Particles ◽  
Acetabular Cup ◽  
Hip Joint Replacement ◽  
Worn Surface ◽  
Ultra High Molecular Weight

In order to investigate the biotribology behavior of a novel artificial joint pair composed of a carbon/carbon composite femoral head and an ultra-high molecular weight polyethylene (UHMWPE) acetabular cup, a hip joint simulator was employed to predict the clinical wear behavior with a constant load and a lubricant of newborn calf serum. The worn surface and the wear particles generated were analyzed by scanning electron microscopy and laser particle size analyzer. The results showed that the worn surface of UHMWPE had a ripple-like morphology with plentiful furrows. The wear particles generated had various morphologies with a size concentrated at about 15 μm.

Effects of Counterface Roughness and Conformity on the Tribological Performance of Crosslinked and Non-crosslinked Medical-Grade Ultra-High Molecular Weight Polyethylene

2002 ◽  
Vol 724 ◽  
Author(s):  
A. D. Chawan ◽  
A. M. Chakravartula ◽  
J. Zhou ◽  
L. A. Pruitt ◽  
M. Ries ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Surface Roughness ◽  
High Molecular Weight ◽  
Wear Mechanisms ◽  
Wear Behavior ◽  
Control Sample ◽  
Total Joint Replacements ◽  
Pin On Disk ◽  
Ultra High Molecular Weight ◽  
Medical Grade

AbstractThe tribological behavior of crosslinked ultra-high molecular weight polyethylene (UHMWPE) was compared to that of non-crosslinked UHMWPE, used as control sample. A reciprocating pin-on-disk tribometer was used to determine the effects of countersurface roughness and conformity on wear mechanisms occurring during the initial stage of sliding. Pin samples of two different radii of curvature were slid against medical-grade Co-Cr alloy disks with surface roughness ranging from 0.005 to 0.04 μm in a lubricant of bovine serum. Normal loads were chosen to provide physiological contact stresses. The focus of this study was on the dependence of early wear mechanisms on surface roughness and conformity. Although a correlation between coefficient of friction data and dominant wear mechanisms was not observed, different wear mechanisms were found between control and crosslinked UHMWPE. The results of this study provide insight into the differences of the initial wear behavior of noncrosslinked and crosslinked UHMWPE used in total joint replacements.

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