The osteolytic potential of polyethylene wear debris in periprosthetic tissues surrounding total joint replacements

As the aseptic loosening induced by polyethylene wear debris is the main cause of long-term failure of total joint replacements, increasing the wear resistance of ultrahigh molecular weight polyethylene (UHMWPE) will be very important to obtain long-life artificial joint. In this paper the UHMWPE was implanted with 450 keV N+ ions to three doses of 5×1014/cm2, 2.5×1015/cm2 and 1.25×1016/cm2. The friction and wear behaviors of UHMWPE were studied under lubrication of distilled water and blood plasma using a ball-on-disk tribometer with a ZrO2 ceramic ball as a counterface. Experimental results showed that the friction coefficient of ions implanted UHMWPE are higher than un-implanted UHMWPE. Under blood plasma lubrication condition, the wear rate of implanted UHMWPE was lower than un-implanted UHMWPE, and the wear rate decreased with increasing implantation dose. The plow, plastic deformation and fatigue were wearing mechanism for un-implanted UHMWPE and the abrasive wear for implanted UHMWPE.

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Simulation of Fretting Wear at Orthopaedic Implant Interfaces

Journal of Biomechanical Engineering ◽

10.1115/1.1894121 ◽

2005 ◽

Vol 127 (3) ◽

pp. 357-363 ◽

Cited By ~ 14

Author(s):

Edward Ebramzadeh ◽

Fabrizio Billi ◽

Sophia N. Sangiorgio ◽

Sarah Mattes ◽

Werner Schmoelz ◽

...

Keyword(s):

Cortical Bone ◽

Wear Debris ◽

Fretting Wear ◽

Orthopaedic Implant ◽

Joint Replacements ◽

Total Joint Replacements ◽

Wear Simulator ◽

Plasma Sprayed ◽

Fiber Mesh

Osteolysis due to wear debris is a primary cause of failure of total joint replacements. Although debris produced by the joint articulating surfaces has been studied and simulated extensively, fretting wear debris, produced at nonarticulating surfaces, has not received adequate attention. We developed a three-station fretting wear simulator to reproduce in vivo motion and stresses at the interfaces of total joint replacements. The simulator is based on the beam bending theory and is capable of producing cyclic displacement from 3to1000microns, under varying magnitudes of contact stresses. The simulator offers three potential advantages over previous studies: The ability to control the displacement by load, the ability to produce very small displacements, and dynamic normal loads as opposed to static. A pilot study was designed to test the functionality of the simulator, and verify that calculated displacements and loads produced the predicted differences between two commonly used porous ingrowth titanium alloy surfaces fretting against cortical bone. After 1.5 million cycles, the simulator functioned as designed, producing greater wear of bone against the rougher plasma-sprayed surface compared to the fiber-mesh surface, as predicted. A novel pin-on-disk apparatus for simulating fretting wear at orthopaedic implant interfaces due to micromotion is introduced. The test parameters measured with the fretting wear simulator were as predicted by design calculations, and were sufficient to measure differences in the height and weight of cortical bone pins rubbing against two porous ingrowth surfaces, plasma-sprayed titanium and titanium fiber mesh.

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The size and shape of particulate polyethylene wear debris in total joint replacements

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

10.1243/0954411971534638 ◽

1997 ◽

Vol 211 (1) ◽

pp. 11-15 ◽

Cited By ~ 90

Author(s):

A Kobayashi ◽

W Bonfield ◽

Y Kadoya ◽

T Yamac ◽

M A R Freeman ◽

...

Keyword(s):

High Performance ◽

Polyethylene Wear ◽

Exact Nature ◽

Joint Replacements ◽

Total Joint Replacements ◽

Total Knee Replacements ◽

Knee Replacements ◽

Hip Replacements ◽

Total Knee

Osteolysis induced by wear particles has been recognized as one of the major causes of long-term failure in total joint replacements. However, little is currently known about the exact nature of particles, as the particles are too small to be characterized by light microscopy. In this study, ultra-high molecular weight polyethylene (UHMWPE) particles retrieved from ten cases (six cemented and four uncemented) for Freeman type conforming tibiofemoral total knee replacements (TKRs), three Charnley total hip replacements (THRs) and five Imperial College/London Hospital double cup surface hip replacements for aseptic loosening were extracted using a high-performance method with ultracentrifugation and characterized by scanning electron microscopy. The equivalent circle diameter (ECD) of all 18 cases ranged from 0.40 to 1.15 μm (Mean ± SE = 0.70 ± 0.05 μm, median = 0.67 μm). The aspect ratio was 1.50 to 2.04 (Mean ± SE = 1.75 ± 0.04, median = 1.73), and roundness was 1.24 to 2.34 (Mean ± SE = 1.61 ± 0.07, median = 1.65). The numbers of particles were 5.2 × 108 to 9.17 × 1010/g tissue (Mean ± SE = 1.42 × 1010 ± 5.41 × 109/g tissue, median = 7.04 × 109). The number of polyethylene (PE) particles/g tissue in TKRs was significantly larger than that in THRs (1.04 × 1010/g tissue and 2.16 × 109/g tissue respectively, median. p = 0.03, Mann-Whitney U test). Unstable fixation of the tibial PE component might account for the accumulation of a large number of PE particles in the interface tissue.

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