Wear Simulation of Metal on Metal Hip Replacements: An Analytical Approach

2012 ◽  
Author(s):  
Lorenza Mattei ◽  
Francesca Di Puccio ◽  
Enrico Ciulli
Keyword(s):  
Hip Replacement ◽  
Experimental Tests ◽  
Wear Model ◽  
Wear Rates ◽  
Metal On Metal ◽  
Hip Replacements ◽  
Wear Law ◽  
Implant Wear

Hip replacement failure is mainly attributable to the implant wear. Consequently preclinical wear evaluations are extremely important. As experimental tests are attractive but highly cost/time demanding, several predictive models have been proposed mainly based on finite element simulations and for metal on plastic (MoP) implants. The aim of this study is to develop a mathematical wear model of metal on metal prostheses, revision of the previous one for MoP implants, developed by the same authors. The model, based on the Archard wear law and on the Hertzian theory, was applied to compare a total (THR) and a resurfacing (RHR) hip replacement under both in vivo and in vitro gait conditions. The results were in agreement with the literature predicting wear rates significantly higher for the RHR than for the THR. The effect of the boundary conditions on wear rates/maps was also investigated and the model limitations discussed.

Understanding the differences between the wear of metal-on-metal and ceramic-on-metal total hip replacements

2008 ◽  
Vol 222 (3) ◽  
pp. 285-296 ◽  
Author(s):  
C G Figueiredo-Pina ◽  
Y Yan ◽  
A Neville ◽  
J Fisher
Keyword(s):  
Open Circuit ◽  
Long Term Results ◽  
Cobalt Chromium ◽  
Material Loss ◽  
Hip Simulator ◽  
Metal On Metal ◽  
Hip Replacements ◽  
Efficient Alternative

Hip simulator studies have been carried out extensively to understand and test artificial hip implants in vitro as an efficient alternative to obtaining long-term results in vivo. Recent studies have shown that a ceramic-on-metal material combination lowers the wear by up to 100 times in comparison with a typical metal-on-metal design. The reason for this reduction remains unclear and for this reason this study has undertaken simple tribometer tests to understand the fundamental material loss mechanisms in two material combinations: metal-on-metal and ceramic-on-ceramic. A simple-configuration reciprocating pin-on-plate wear study was performed under open-circuit potential (OCP) and with applied cathodic protection (CP) in a serum solution using two tribological couples: firstly, cobalt—chromium (Co—Cr) pins against Co—Cr plates; secondly, Co—Cr pins against alumina (Al2O3) plates. The pin and plate surfaces prior to and after testing were examined by profilometry and scanning electron microscopy. The results showed a marked reduction in wear when CP was applied, indicating that total material degradation under the OCP condition was attributed to corrosion processes. The substitution of the Co—Cr pin with an Al2O3 plate also resulted in a dramatic reduction in wear, probably due to the reduction in the corrosion—wear interactions between the tribological pair.

scholarly journals A simple method of suspending implant wear particles for more physiological modelling of cell-particle interactions in vitro

2021 ◽  
Author(s):  
Christine Poon
Keyword(s):  
Wear Debris ◽  
Culture Media ◽  
Polymeric Materials ◽  
Wear Particle ◽  
Physicochemical Characteristics ◽  
Wear Particles ◽  
Simple Method ◽  
Implant Wear

AbstractArthroplasty implants e.g. hip, knee, spinal disc sustain relatively high compressive loading and friction wear, which lead to the formation of wear particles or debris between articulating surfaces. Despite advances in orthopaedic materials and surface treatments, the production of wear debris from any part of a joint arthroplasty implant is currently unavoidable. Implant wear debris induces host immune responses and inflammation, which causes patient pain and ultimately implant failure through progressive inflammation-mediated osteolysis and implant loosening, where the severity and rate of periprosthetic osteolysis depends on the material and physicochemical characteristics of the wear particles. Evaluating the cytotoxicity of implant wear particles is important for regulatory approved clinical application of arthroplasty implants, as is the study of cell-particle response pathways. However, the wear particles of polymeric materials commonly used for arthroplasty implants tend to float when placed in culture media, which limits their contact with cell cultures. This study reports a simple means of suspending wear particles in liquid medium using sodium carboxymethyl cellulose (NaCMC) to provide a more realistic proxy of the interaction between cells and tissues to wear particles in vivo, which are free-floating in synovial fluid within the joint cavity. Low concentrations of NaCMC dissolved in culture medium were found to be effective for suspending polymeric wear particles. Such suspensions may be used as more physiologically-relevant means for testing cellular responses to implant wear debris, as well as studying the combinative effects of shear and wear particle abrasion on cells in a dynamic culture environments such as perfused tissue-on-chip devices.

In Vitro Experimental Investigation of the Integrity of the Stem–Cement Interface

2013 ◽  
Vol 647 ◽  
pp. 53-56
Author(s):  
Hong Yu Zhang ◽  
Leigh Fleming ◽  
Liam Blunt
Keyword(s):  
Experimental Investigation ◽  
Fluid Flow ◽  
Hip Replacement ◽  
Hip Prosthesis ◽  
Vitro Experiment ◽  
Cement Interface ◽  
In Vitro Experiment ◽  
Mechanical Bonding

The rationale behind failure of cemented total hip replacement is still far from being well understood in a mechanical and molecular perspective. In the present study, the integrity of the stem–cement interface was investigated through an in vitro experiment monitoring fluid flow along this interface. The results indicated that a good mechanical bonding formed at the stem–cement interface before debonding of this interface was induced by physiological loadings during the in vivo service of the hip prosthesis.

Influence of particulate and dissociated metal-on-metal hip endoprosthesis wear on mesenchymal stromal cells in vivo and in vitro

Biomaterials ◽  
2016 ◽  
Vol 98 ◽  
pp. 31-40 ◽  
Author(s):  
Anastasia Rakow ◽  
Janosch Schoon ◽  
Anke Dienelt ◽  
Thilo John ◽  
Martin Textor ◽  
...  
Keyword(s):  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Hip Endoprosthesis ◽  
Metal On Metal

Ion release in ceramic bearings for total hip replacement: Results from an in vitro and an in vivo study

2017 ◽  
Vol 42 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Jan Philippe Kretzer ◽  
Ulrike Mueller ◽  
Marcus R. Streit ◽  
Hartmuth Kiefer ◽  
Robert Sonntag ◽  
...  
Keyword(s):  
Total Hip Replacement ◽  
Hip Replacement ◽  
In Vivo Study ◽  
Ion Release ◽  
Total Hip

scholarly journals Reproduction of fretting wear at the stem—cement interface in total hip replacement

2007 ◽  
Vol 221 (8) ◽  
pp. 963-971 ◽  
Author(s):  
L Brown ◽  
H Zhang ◽  
L Blunt ◽  
S Barrans
Keyword(s):  
Bone Cement ◽  
Total Hip Replacement ◽  
Hip Replacement ◽  
Fatigue Cracks ◽  
Cement Mantle ◽  
Fretting Wear ◽  
Cement Interface ◽  
Total Hip

The stem-cement interface experiences fretting wear in vivo due to low-amplitude oscillatory micromotion under physiological loading, as a consequence it is considered to play an important part in the overall wear of cemented total hip replacement. Despite its potential significance, in-vitro simulation to reproduce fretting wear has seldom been attempted and even then with only limited success. In the present study, fretting wear was successfully reproduced at the stem-cement interface through an in-vitro wear simulation, which was performed in part with reference to ISO 7206-4: 2002. The wear locations compared well with the results of retrieval studies. There was no evidence of bone cement transfer films on the stem surface and no fatigue cracks in the cement mantle. The cement surface was severely damaged in those areas in contact with the fretting zones on the stem surface, with retention of cement debris in the micropores. Furthermore, it was suggested that these micropores contributed to initiation and propagation of fretting wear. This study gave scope for further comparative study of the influence of stem geometry, stem surface finish, and bone cement brand on generation of fretting wear.

Alternative Bearing Couples in Total Hip Replacements: Solutions for Young Patients

2003 ◽  
Vol 13 (2_suppl) ◽  
pp. 31-35 ◽  
Author(s):  
J. Fisher ◽  
E. Ingham ◽  
M.H. Stone
Keyword(s):  
Polyethylene Wear ◽  
Young Patients ◽  
Volumetric Wear ◽  
Wear Rates ◽  
Total Hip Replacements ◽  
Metal On Metal ◽  
Hip Replacements ◽  
Gamma Irradiated ◽  
Ceramic On Ceramic

There is now considerable clinical concern about the effect of polyethylene wear debris induced osteolysis in long term failure of hip replacements. This paper compares the wear of stabilised and crosslinked polyethylene to alternative hard on hard bearings. The volumetric wear rates of stabilised and moderately crosslinked polyethylene 50 to 35 mm3/million cycles were less than previously reported for historical gamma irradiated in air polyethylene, but still of a level that in the long term could cause osteolysis. The moderately crosslinked polyethylene produced less wear than non-crosslinked polyethylene, but particles were smaller and more reactive resulting in little change in the osteolytic potential. Alumina ceramic on ceramic produced substantially less wear and osteolytic potential. Metal on metal also produced less wear than polyethylene but the particles adversely influence cell viability.

Quantification of self-polishing in vivo from explanted metal-on-metal total hip replacements

2011 ◽  
Vol 44 (5) ◽  
pp. 513-516 ◽  
Author(s):  
Thomas J. Joyce ◽  
Harry Grigg ◽  
David J. Langton ◽  
Antoni V.F. Nargol
Keyword(s):  
Total Hip ◽  
Total Hip Replacements ◽  
Metal On Metal ◽  
Hip Replacements

Can cobalt levels estimate in-vivo wear of metal-on-metal bearings used in hip arthroplasty?

2007 ◽  
Vol 221 (8) ◽  
pp. 929-942 ◽  
Author(s):  
M Khan ◽  
J H Kuiper ◽  
J B Richardson
Keyword(s):  
Clinical Studies ◽  
Wear Debris ◽  
Metal Ion ◽  
Large Diameter ◽  
Small Diameter ◽  
Wear Rates ◽  
Hip Simulator ◽  
Metal On Metal ◽  
Metal Levels

High levels of cobalt and chromium ions are detected in the blood and urine of patients with metal-on-metal (MoM) hip replacement. These elements are released as a result of wear at the bearing surfaces. Wear rates depend on a multitude of factors, which include the bearing geometry, carbon content, manufacturing processes, lubrication, speed and direction of sliding of the surfaces, pattern of loading, and orientation of the components. In-vivo wear of MoM bearings cannot be reliably measured on X-rays because no distinction can be made between the bearing surfaces. Hip simulator studies have shown that wear rates are higher during the initial bedding-in phase and subsequently drop to very low levels. Accordingly, metal ion levels would be expected to decrease with the use of the bearing, measured as implantation time following surgery. However, several clinical studies have found that metal ion levels either gradually rise or fluctuate instead of decreasing to lower levels. Moreover, hip simulator studies predict that large-diameter bearings have lower wear rates than small-diameter bearings. In clinical studies, however, metal levels in patients with large-diameter bearings are unexpectedly higher than those in patients with small-diameter bearings. As a consequence, high cobalt ion levels in patients do not necessarily imply that their MoM bearings produce much wear debris at the time that their levels were measured; it may simply be due to accumulation of wear debris from the preceding time. Exercise-related cobalt rise may overcome this limitation and give a better assessment of the current wear status of a MoM bearing surface than a measure of cobalt levels only.

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