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Zhongxiao Peng - One of the best experts on this subject based on the ideXlab platform.
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Restoration of low-informative image for robust Debris shape measurement in on-line Wear Debris monitoring
Mechanical Systems and Signal Processing, 2019Co-Authors: Ngaiming Kwok, Yeping Peng, Zhongxiao PengAbstract:Abstract As a significant technique in machine condition monitoring, Wear Debris analysis enables investigation of machine running condition with respect to Debris features including size, quantity and morphology. In particular, being capable of providing more comprehensive morphological information, three-dimensional Debris features are regarded essential and often acquired through a video-based Debris imaging process. However, Debris images captured often suffer degradation due to Debris motion blur and lubrication contamination, that hinder reliable Debris features extraction. To address the image degradation issue, a new method of Wear Debris image restoration is developed to reduce the effect of blur. In order to avoid the expensive computation involved in blind deconvolution methods, the Debris image was restored using localized boundary features. Based on the fact that Debris area and background area indicate distinctive brightness, a step edge model is applied to describe the original Debris boundary. Localized kernels on each side of Debris are then determined. Next, restorations are conducted with the estimated kernels to produce sharper Debris profiles with respect to different motion features. Final restoration is conducted by fusing the restored profiles according to the maximum local sharpness. Experimental results have demonstrated that this method allows reliable features extraction from blurred image, improving the robustness of video based Wear Debris analysis.
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prediction of Wear trend of engines via on line Wear Debris monitoring
Tribology International, 2018Co-Authors: Wei Cao, Youbai Xie, Guangneng Dong, Zhongxiao PengAbstract:Abstract On-line Wear Debris monitoring is a useful technology for real-time machine Wear condition monitoring but needs further development. This study, based on previous developments of an on-line visual ferrograph (OLVF), focused on (i) data reconstruction for extracting representative and reliable Wear condition related characteristics, and (ii) development of an improved model for on-line Wear prediction. Wear monitoring of a diesel engine was performed using this on-line Wear Debris monitoring system. Experimental results and comparisons between the improved relevance vector machine (RVM) model and other models show that the improved RVM model gives an earlier warning and enhances the prediction accuracy.
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Oxidation Wear monitoring based on the color extraction of on-line Wear Debris
Wear, 2015Co-Authors: Yeping Peng, Tonghai Wu, Shuo Wang, Zhongxiao PengAbstract:Oxidation associated Wear usually involves high temperature and often accelerates lubrication degradation and failure processes. The color of oxide Wear Debris highly corresponds with the severities of oxidation Wear. Therefore, on-line detection of oxide Wear Debris has the advantage of revealing the Wear condition in a timely manner. This paper presents a color extraction method of Wear Debris for on-line oxidation monitoring. Images of moving Wear particles in lubricant were captured via an on-line imaging system. Image preprocessing methods were adopted to separate Wear particles from the background and to improve the image quality through a motion-blurred restoration process before the colors of the Wear Debris were extracted. By doing this, two typical types of oxide Wear Debris, red Fe2O3and black Fe3O4, were identified. Furthermore, a statistical clustering model was established for automatic determination of the two typical types of oxide Wear particles. Finally, the effectiveness of the proposed method was verified by performing real-time oxidation Wear monitoring of experimental data. The proposed method provides a feasible approach to detect early oxidation Wear and monitor its progress in a running machine.
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watershed based morphological separation of Wear Debris chains for on line ferrograph analysis
Tribology Letters, 2014Co-Authors: Yeping Peng, Zhongxiao PengAbstract:Separation and characterization of Wear Debris from ferrograph images are demanded for on-line analysis. However, particle overlapping issue associated with Wear Debris chains has markedly limited this technique due to the difficulty in effectively segmenting individual particles from the chains. To solve this bottleneck problem, studies were conducted in this paper to establish a practical method for Wear Debris separation for on-line analysis. Two conventional watershed approaches were attempted. Accordingly, distance-based transformation had a problem with oversegmentation, which led to overcounting of Wear Debris. Another method, by integrating the ultimate corrosion and condition expansion (UCCE), introduced boundary-offset errors that unavoidably affected the boundary identification between particles, while varying the corrosion scales and adopting a low-pass filtering method improved the UCCE with satisfactory results. Finally, together with a termination criterion, an automatic identification process was applied with real on-line Wear Debris images sampled from a mineral scraper gearbox. With the satisfactory separation result, several parameters for characterization were extracted and some statistics were constructed to obtain an overall evaluation of existing particles. The proposed method shows a promising prospect in on-line Wear monitoring with deep insight into Wear mechanism.
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integration of Wear Debris and vibration analysis for machine condition monitoring
2003Co-Authors: Zhongxiao Peng, N.j. KessissoglouAbstract:In this paper, the correlation of vibration analysis and Wear Debris analysis for machine condition monitoring is both qualitatively and quantitatively investigated. Various Wear conditions were generated, using an experimental test rig consisting of a spur gearbox driven by an electric motor in order to examine the correlation of the two techniques. Two tests were conducted under the following two controlled operating conditions corresponding to constant normal load and constant overload. Oil samples and vibration data were collected regularly. Wear Debris analysis included the study of particle number and size distribution, the examination of particle morphology and types to determine possible Wear mechanisms, Wear rates and Wear sources. Fault detection in the vibration signature was compared with the particle analysis. The results from this paper have given more understanding on the dependent and independent roles of vibration and Wear Debris analyses in machine condition monitoring and fault diagnosis.
J L Tipper - One of the best experts on this subject based on the ideXlab platform.
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three dimensional particle embedded agarose gels for simultaneous biocompatibility testing of polymer metal and ceramic Wear Debris
Orthopaedic Proceedings, 2018Co-Authors: S Lal, R M Hall, J L TipperAbstract:IntroductionCurrently, different techniques to evaluate biocompatibility of orthopaedic materials, including two-dimensional (2D) cell culture for metal and ceramic Wear Debris and floating 2D surfaces or three-dimensional (3D) agarose gels for UHMWPE Wear Debris, are used. We have developed a single method using 3D agarose gels that is suitable to test the biocompatibility of all three types of Wear Debris simultaneously. Moreover, stimulation of the cells by Wear particles embedded in a 3D gel better mimics the in vivo environment.Materials and MethodsClinically relevant sterile UHMWPE and CoCr Wear particles were generated using methodologies described previously [1,2]. Commercially available nanoscale and micron-sized silicon nitride (Si3N4) particles (<50 nm and <1 μm, Sigma UK) were sterilised by heat treatment for 4h at 180°C. Agarose-particle suspensions were prepared by mixing warm 2% (w/v) low-melting-point agarose solution with the particles dispersed by sonication in DMEM culture media. The su...
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three dimensional particle embedded agarose gels for simultaneous biocompatibility testing of polymer metal and ceramic Wear Debris
Journal of Bone and Joint Surgery-british Volume, 2017Co-Authors: S Lal, R M Hall, J L TipperAbstract:Introduction Currently, different techniques to evaluate biocompatibility of orthopaedic materials, including two-dimensional (2D) cell culture for metal and ceramic Wear Debris and floating 2D surfaces or three-dimensional (3D) agarose gels for UHMWPE Wear Debris, are used. We have developed a single method using 3D agarose gels that is suitable to test the biocompatibility of all three types of Wear Debris simultaneously. Moreover, stimulation of the cells by Wear particles embedded in a 3D gel better mimics the in vivo environment. Materials and Methods Clinically relevant sterile UHMWPE and CoCr Wear particles were generated using methodologies described previously [1,2]. Commercially available nanoscale and micron-sized silicon nitride (Si3N4) particles (<50 nm and <1 μm, Sigma UK) were sterilised by heat treatment for 4h at 180°C. Agarose-particle suspensions were prepared by mixing warm 2% (w/v) low-melting-point agarose solution with the particles dispersed by sonication in DMEM culture media. The suspensions were then allowed to set at room temperature for 10 min in 96 well culture plates. Sub-confluent L929 murine fibroblasts were cultured on the prepared gels for up to 6 days in 5% (v/v) CO2 at 37°C. After incubation, the viability of cells was measured using the ATP-lite assay. The results were expressed as mean ± 95% confidence limits and the data was analysed using one-way ANOVA and Tukey-Kramer post-hoc analysis. Results and Discussion The gels were observed to ensure uniform distribution of particles and migration of cells into the gel. No significant reduction in viability was observed for nanoscale and micron-sized Si3N4 particles at low doses (0.5 μm3 per cell) and high doses (50 μm3 per cell), or for UHMWPE Wear Debris at high doses (100 μm3 per cell) [Figure1]. Moreover, the viability was significantly reduced for high doses of CoCr Wear Debris (50 μm3 per cell) and the positive control, camptothecin (2 μg.ml−1) at day 6 [Figure1]. These results are consistent with the literature [2,3] and therefore validate our 3D agarose cell culture method for comparing cytotoxicity of polymer, metal and ceramic particles in a single assay, simultaneously. Conclusion Biocompatibility ofpolymer, metal and ceramic Wear Debris can be tested simultaneously by using 3D particle embedded agarose gels. Acknowledgements The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. GA-310477 LifeLongJoints.
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comparative Wear and Wear Debris under three different counterface conditions of crosslinked and non crosslinked ultra high molecular weight polyethylene
Bio-medical Materials and Engineering, 2001Co-Authors: M M Endo, Eileen Ingham, J Fisher, D C Barton, P S M Barbour, J L Tipper, M H StoneAbstract:The Wear Debris generated from ultra high molecular weight polyethylene (UHMWPE) have been recognised as one of the major causes of failure in total hip replacements (THR). It is essential to reduce the Wear Debris generated from UHMWPE acetabular cups in order to minimise this problem. Debris in the submicron size range is believed to have greater osteolytic potential. It is now known that crosslinked UHMWPE acetabular cups have reduced volumetric Wear rates but little is known about the influence of crosslinking on the size and morphology of the Wear Debris. In this study, the Wear of grade GUR 1020 crosslinked (vacuum gamma irradiated), GUR 1120 crosslinked (acetylene enhanced irradiated) and non cross linked (ethylene oxide sterilised) GUR 1020 UHMWPE was compared in multidirectional pin-on-plate Wear tests under three different counterface conditions (smooth, isotropically rough and scratched counterfaces). Multidirectional motion was chosen because this motion was closer to the relative motion in the natural hip. From this study, better Wear resistance of crosslinked UHMWPE compared with non-crosslinked UHMWPE was demonstrated for the smooth counterface conditions. However, in the rough and scratched counterface conditions, the vacuum gamma irradiated crosslinked material produced significantly higher Wear rates than the non-crosslinked material. The analysis of the Wear Debris showed that the majority of the volume of the acetylene enhanced crosslinked UHMWPE Wear Debris was in the most biologically active size range (0.1 to 0.5 microm). In contrast, the non-crosslinked material and the vacuum gamma irradiated crosslinked material had a greater proportion of the volume of the Debris in the larger size ranges which are less biologically active. This has important implications for its osteolytic potential.
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quantitative analysis of polyethylene Wear Debris Wear rate and head damage in retrieved charnley hip prostheses
Journal of Materials Science: Materials in Medicine, 2000Co-Authors: J L Tipper, Eileen Ingham, J Fisher, B M Wroblewski, J L Hailey, A A Besong, M H StoneAbstract:Submicrometer- and micrometer-sized ultra-high molecular weight polyethylene (UHMWPE) Wear particles have been associated with osteolysis and failure of total artificial joints. Previous studies have isolated predominantly submicrometer-sized particles at the expense of larger particles (>10 μm). This study aimed to isolate and characterize quantitatively all sizes of UHMWPE Wear particles generated in 18 Charnley hip prostheses. In addition, to analyze the Wear Debris with respect to the total volumetric Wear of the cup and damage to the femoral head. Particle size distributions ranged from 0.1 to ->1000 μm. A significant proportion (3–82%) of the mass of the Wear Debris isolated was>10 μm. The mode of the frequency distribution of the particles was in the range 0.1–0.5 μm for all patients. However, analysis of the mass of Wear Debris as a function of its size allowed differentiation of the Wear Debris from different patients. Femoral head damage was associated with high volumetric Wear and increased numbers of biologically active submicrometer-sized particles.
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quantitative analysis of the Wear and Wear Debris from low and high carbon content cobalt chrome alloys used in metal on metal total hip replacements
Journal of Materials Science: Materials in Medicine, 1999Co-Authors: J L Tipper, J Fisher, M H Stone, P J Firkins, E Ingham, R FarrarAbstract:The biological reactions to polyethylene Wear Debris have been shown to result in osteolysis and loosening of total hip arthroplasties. This has led to renewed interest in the use of metal on metal bearings in hip prostheses. This study employed uniaxial and biaxial multistation pin on plate reciprocators to assess how the carbon content of the cobalt chrome alloy and the types of motion affected the Wear performance of the bearing surfaces and the morphology of the Wear Debris generated.
B M Wroblewski - One of the best experts on this subject based on the ideXlab platform.
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quantitative analysis of polyethylene Wear Debris Wear rate and head damage in retrieved charnley hip prostheses
Journal of Materials Science: Materials in Medicine, 2000Co-Authors: J L Tipper, Eileen Ingham, J Fisher, B M Wroblewski, J L Hailey, A A Besong, M H StoneAbstract:Submicrometer- and micrometer-sized ultra-high molecular weight polyethylene (UHMWPE) Wear particles have been associated with osteolysis and failure of total artificial joints. Previous studies have isolated predominantly submicrometer-sized particles at the expense of larger particles (>10 μm). This study aimed to isolate and characterize quantitatively all sizes of UHMWPE Wear particles generated in 18 Charnley hip prostheses. In addition, to analyze the Wear Debris with respect to the total volumetric Wear of the cup and damage to the femoral head. Particle size distributions ranged from 0.1 to ->1000 μm. A significant proportion (3–82%) of the mass of the Wear Debris isolated was>10 μm. The mode of the frequency distribution of the particles was in the range 0.1–0.5 μm for all patients. However, analysis of the mass of Wear Debris as a function of its size allowed differentiation of the Wear Debris from different patients. Femoral head damage was associated with high volumetric Wear and increased numbers of biologically active submicrometer-sized particles.
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osteolysis due to particle Wear Debris following total hip arthroplasty the role of high density polyethylene
Journal of Bone and Joint Surgery American Volume, 1994Co-Authors: B M WroblewskiAbstract:It seems likely that the osteolysis seen in total hip arthroplasty, and commonly attributed to Wear Debris, is actually caused by changes of volume and pressure in the cavity housing the implant. Improvements in cementing technique reduce the incidence of osteolysis. There is no evidence to suggest that this osteolysis is a biological response to Wear Debris or that the process is different on the femoral and the acetabular side. Similar changes can be seen on both sides of an arthritic hip joint that has not been subjected to surgery.
Ian C Clarke - One of the best experts on this subject based on the ideXlab platform.
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polyethylene Wear Debris produced in a knee simulator model effect of crosslinking and counterface material
Journal of Biomedical Materials Research Part B, 2010Co-Authors: P A Williams, Cindy M Brown, Riichro Tsukamoto, Ian C ClarkeAbstract:Polyethylene (PE) Debris has been well studied in clinical retrievals and laboratory Wear simulations of total hip replacements. However, little is known about PE Debris from total knee replacements. In this study, we investigated the effects of crosslinking PE bearings and alternate counterface material. Mildly (35 kGy) and highly (70 kGy) crosslinked PE were studied in combination with CoCr and zirconia femoral counterfaces. Wear Debris was isolated and its morphology characterized. Except for changes in PE Debris size with the zirconia bearings, there were no morphological changes greater than 10%. The average submicron volume fraction decreased from about 65% to 45% with both increased crosslinking and changing counterface material from CoCr to zirconia. The averaged number of generated particles decreased by ∼fourfold with increased crosslinking and threefold with changing counterface material from CoCr to zirconia. This showed that the degree of PE crosslinking and the choice of counterface material were important factors in the PE Wear Debris production in total knee simulator replacements. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
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polyethylene Wear Debris produced in a knee simulator model effect of crosslinking and counterface material
ASME STLE 2007 International Joint Tribology Conference Parts A and B, 2007Co-Authors: P A Williams, Cindy M Brown, Riichro Tsukamoto, Takashi Nakamura, Ian C ClarkeAbstract:Polyethylene (PE) Debris has been examined in total hip replacements from clinical retrievals and laboratory simulator studies, but little is known about PE Debris from total knee replacements. In this study we investigated the effects of crosslinking PE and the counterface material. Mildly and highly crosslinked PE were studied in combination with CoCr and Zirconia femoral components. Wear was determined by gravimetric measurements and the Wear Debris was isolated and morphologically characterized. Although the zirconia counterface with 7 Mrad PE did not exhibit measurable Wear, Wear Debris was found. This indicated that Wear occurred below the limits of the gravimetric approach. This study showed that the amount of crosslinking of PE and the counterface material were important factors in the Wear of PE in a knee simulator model.© 2007 ASME
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mechanism and clinical significance of Wear Debris induced osteolysis
Clinical Orthopaedics and Related Research, 1992Co-Authors: Harlan C Amstutz, Pat Campbell, Nir Kossovsky, Ian C ClarkeAbstract:Loosening of joint replacement components is often multifactorial. The quality of initial fixation is very important to the outcome of the arthroplasty and is often a factor in short-term and long-term failure. This paper discusses another important factor of implant loosening, namely Wear Debris induced osteolysis. Macrophages activated by the phagocytosis of particulate Wear Debris are the key cells in this process, which can potentially occur in any implant system regardless of implant design or fixation mode. This is because each implant system creates Wear Debris from the articulating surfaces and the interfaces. The clinical consequences of Wear Debris cover a broad spectrum from radiolucencies to massive osteolysis and implant failure. For this reason, the reduction of Wear Debris should be a primary goal of orthopedic research in the future.
J Fisher - One of the best experts on this subject based on the ideXlab platform.
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alumina alumina artificial hip joints part i a histological analysis and characterisation of Wear Debris by laser capture microdissection of tissues retrieved at revision
Biomaterials, 2002Co-Authors: A Hatton, J Fisher, Jim Nevelos, A B Nevelos, Rosamonde E Banks, Eileen InghamAbstract:The aims of this study were to investigate the tissues from uncemented Mittelmeier alumina ceramic-on-ceramic total hip replacements using histological methods and to isolate and characterise the ceramic Wear Debris using laser capture microdissection and electron microscopy. Tissues from around 10 non-cemented Mittelmeier alumina ceramic on ceramic THRs were obtained from patients undergoing revision surgery. Tissues were also obtained from six patients who were undergoing revisions for aseptic loosening of Charnley, metal-on-polyethylene prostheses. Tissue sections were analysed using light microscopy to determine histological reactions and also the location and content of alumina ceramic Wear Debris. Tissue samples were extracted from sections using laser capture microdissection and the characteristics of the particles subsequently analysed by TEM and SEM. The tissues from around the ceramic-on-ceramic prostheses all demonstrated the presence of particles, which could be seen as agglomerates inside cells or in distinct channels in the tissues. The tissues from the ceramic-on-ceramic retrievals had a mixed pathology with areas that had no obvious pathology, areas that were relatively rich in macrophages and over half of the tissues had in the region of 60% necrosis/necrobiosis. In comparison, the Charnley tissues showed a granulomatous cellular reaction involving a dense macrophage infiltrate and the presence of giant cells and < 30% necrosis/necrobiosis. The tissues from the ceramic prostheses also showed the presence of neutrophils and lymphocytes, which were not evident in the tissues from the Charnley retrievals. There were significantly more macrophages (p < 0.05), and giant cells (p < 0.01) in the Charnley tissues and significantly more neutrophils (p < 0.01) in the ceramic-on-ceramic tissues. TEM of the laser captured tissue revealed the presence of very small alumina Wear Debris in the size range 5-90 nm, mean size + SD of 24 +/- 19nm whereas SEM (lower resolution) revealed particles in the 0.05-3.2 microm size range. This is the first description of nanometre sized ceramic Wear particles in retrieval tissues. The bi-modal size range of alumina ceramic Wear Debris overlapped with the size ranges commonly observed with metal particles (10-30 nm) and particles of ultra-high molecular weight polyethylene (0.1-1,000 microm). It is possible that the two size ranges of contributed to the mixed tissue pathology observed. It is speculated that the two types of ceramic Wear Debris are generated by two different Wear mechanisms in vivo, under normal articulating conditions, relief polishing Wear and very small Wear Debris is produced. while under conditions of microseparation of the head and cup and rim contact, intergranular and intragranular fracture and larger Wear particles are generated.
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comparative Wear and Wear Debris under three different counterface conditions of crosslinked and non crosslinked ultra high molecular weight polyethylene
Bio-medical Materials and Engineering, 2001Co-Authors: M M Endo, Eileen Ingham, J Fisher, D C Barton, P S M Barbour, J L Tipper, M H StoneAbstract:The Wear Debris generated from ultra high molecular weight polyethylene (UHMWPE) have been recognised as one of the major causes of failure in total hip replacements (THR). It is essential to reduce the Wear Debris generated from UHMWPE acetabular cups in order to minimise this problem. Debris in the submicron size range is believed to have greater osteolytic potential. It is now known that crosslinked UHMWPE acetabular cups have reduced volumetric Wear rates but little is known about the influence of crosslinking on the size and morphology of the Wear Debris. In this study, the Wear of grade GUR 1020 crosslinked (vacuum gamma irradiated), GUR 1120 crosslinked (acetylene enhanced irradiated) and non cross linked (ethylene oxide sterilised) GUR 1020 UHMWPE was compared in multidirectional pin-on-plate Wear tests under three different counterface conditions (smooth, isotropically rough and scratched counterfaces). Multidirectional motion was chosen because this motion was closer to the relative motion in the natural hip. From this study, better Wear resistance of crosslinked UHMWPE compared with non-crosslinked UHMWPE was demonstrated for the smooth counterface conditions. However, in the rough and scratched counterface conditions, the vacuum gamma irradiated crosslinked material produced significantly higher Wear rates than the non-crosslinked material. The analysis of the Wear Debris showed that the majority of the volume of the acetylene enhanced crosslinked UHMWPE Wear Debris was in the most biologically active size range (0.1 to 0.5 microm). In contrast, the non-crosslinked material and the vacuum gamma irradiated crosslinked material had a greater proportion of the volume of the Debris in the larger size ranges which are less biologically active. This has important implications for its osteolytic potential.
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quantitative analysis of polyethylene Wear Debris Wear rate and head damage in retrieved charnley hip prostheses
Journal of Materials Science: Materials in Medicine, 2000Co-Authors: J L Tipper, Eileen Ingham, J Fisher, B M Wroblewski, J L Hailey, A A Besong, M H StoneAbstract:Submicrometer- and micrometer-sized ultra-high molecular weight polyethylene (UHMWPE) Wear particles have been associated with osteolysis and failure of total artificial joints. Previous studies have isolated predominantly submicrometer-sized particles at the expense of larger particles (>10 μm). This study aimed to isolate and characterize quantitatively all sizes of UHMWPE Wear particles generated in 18 Charnley hip prostheses. In addition, to analyze the Wear Debris with respect to the total volumetric Wear of the cup and damage to the femoral head. Particle size distributions ranged from 0.1 to ->1000 μm. A significant proportion (3–82%) of the mass of the Wear Debris isolated was>10 μm. The mode of the frequency distribution of the particles was in the range 0.1–0.5 μm for all patients. However, analysis of the mass of Wear Debris as a function of its size allowed differentiation of the Wear Debris from different patients. Femoral head damage was associated with high volumetric Wear and increased numbers of biologically active submicrometer-sized particles.
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quantitative analysis of the Wear and Wear Debris from low and high carbon content cobalt chrome alloys used in metal on metal total hip replacements
Journal of Materials Science: Materials in Medicine, 1999Co-Authors: J L Tipper, J Fisher, M H Stone, P J Firkins, E Ingham, R FarrarAbstract:The biological reactions to polyethylene Wear Debris have been shown to result in osteolysis and loosening of total hip arthroplasties. This has led to renewed interest in the use of metal on metal bearings in hip prostheses. This study employed uniaxial and biaxial multistation pin on plate reciprocators to assess how the carbon content of the cobalt chrome alloy and the types of motion affected the Wear performance of the bearing surfaces and the morphology of the Wear Debris generated.
