scholarly journals A COMPARATIVE STUDY ON WEAR BEHAVIOR OF HIP PROSTHESIS BY FINITE ELEMENT SIMULATION

2002 ◽  
Vol 14 (04) ◽  
pp. 139-148 ◽  
Author(s):  
JUI-PIN HUNG ◽  
JAMES SHIH-SHYN WU
Keyword(s):  
Hip Prosthesis ◽  
Polyethylene Wear ◽  
Wear Behavior ◽  
Numerical Approach ◽  
Analysis Model ◽  
Wear Rates ◽  
Femoral Heads ◽  
Artificial Hip Joints ◽  
Pin On Disk

A numerical approach was proposed to investigate the wear behavior occurred in the artificial hip joints in this paper. In the numerical simulations, the wear coefficients taken from pin-on-disk tests were introduced into the wear analysis model to assess the wear rates of polyethylene acetabular cups against metallic or ceramic femoral heads. For the established material combinations, different values of polyethylene wear rates were obtained respectively, which were not necessarily the realistic one as expected in vivo but could be confirmed after further discussion on the wear mechanism involved in wear tests. Current results indicated that the polyethylene/ceramic couples represented better wear performances than the polyethylene/metal couples. Furthermore, the ratio of wear rates for polyethylene cups against alumina and the metallic femoral heads was 0.5, which agreed well with that deduced from clinical studies or laboratory hip simulators. It is obvious that these comparable wear behaviors observed from clinics or laboratory studies also can be found by means of the numerical simulation.

scholarly journals Influence of Metallic Deposition on Ceramic Femoral Heads on the Wear Behavior of Artificial Hip Joints: A Simulator Study

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3569
Author(s):  
Jessica Hembus ◽  
Lisa Rößler ◽  
Mario Jackszis ◽  
Annett Klinder ◽  
Rainer Bader ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Wear Behavior ◽  
Laser Scanning Microscopy ◽  
Wear Testing ◽  
Hip Joints ◽  
Wear Rates ◽  
Artificial Hip ◽  
Femoral Heads ◽  
Wear Simulator ◽  
Artificial Hip Joints

Several retrieval studies have reported on metallic depositions on ceramic femoral heads, but the effect on the wear behavior of artificial hip joints has not been investigated in wear simulator studies. In the present study, retrieved ceramic heads with metallic depositions as third particles were tested against cross-linked ultra-high-molecular-weight polyethylene (UHMWPE) liners in a hip wear simulator. The amount of liner wear and expansion of metallic depositions on the heads were determined before and after wear testing with digital microscopy. The surface roughness of the heads was investigated in areas with and without metallic depositions by laser scanning microscopy. After five million load cycles, a non-significant reduction in the metallic formation on the retrieved heads was found. The metallic areas showed a higher surface roughness compared to unconcerned areas. The liners showed a higher wear rate of 1.57 ± 1.36 mg/million cycles for 28 mm heads and 2.42 ± 0.82 mg/million cycles for 36 mm heads with metallic depositions, in comparison with new ceramic heads with a 28 mm size ((−0.06 ± 0.89) mg/million cycles) and 36 mm size ((2.04 ± 0.46) mg/million cycles). Metallic transfer on ceramic heads can lead to an increased surface roughness and higher wear rates at the UHMWPE liners. Therefore, metallic contact of the ceramic femoral head should be avoided.

scholarly journals Can Pin-on-Disk Testing Be Used to Assess the Wear Performance of Retrieved UHMWPE Components for Total Joint Arthroplasty?

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Steven M. Kurtz ◽  
Daniel W. MacDonald ◽  
Sevi Kocagöz ◽  
Mariya Tohfafarosh ◽  
Doruk Baykal
Keyword(s):  
Wear Behavior ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Volumetric Wear ◽  
Wear Properties ◽  
Wear Rates ◽  
Ultrahigh Molecular Weight ◽  
Aging Conditions ◽  
Novel Method ◽  
Pin On Disk

The objective of this study was to assess the suitability of using multidirectional pin-on-disk (POD) testing to characterize wear behavior of retrieved ultrahigh molecular weight polyethylene (UHMWPE). The POD wear behavior of 25 UHMWPE components, retrieved after 10 yearsin vivo, was compared with 25 that were shelf aged for 10–15 years in their original packaging. Components were gamma sterilized (25–40 kGy) in an air or reduced oxygen (inert) package. 9 mm diameter pins were fabricated from each component and evaluated against CoCr disks using a super-CTPOD with 100 stations under physiologically relevant, multidirectional loading conditions. Bovine serum (20 g/L protein concentration) was used as lubricant. Volumetric wear rates were found to vary based on the aging environment, as well as sterilization environment. Volumetric wear rates were the lowest for the pins in the gamma inert, shelf aged cohort. These results support the utility of using modern, multidirectional POD testing with a physiologic lubricant as a novel method for evaluating wear properties of retrieved UHMWPE components. The data also supported the hypothesis that wear rates of gamma-inert liners were lower than gamma-air liners for both retrieved and shelf aging conditions. However, this difference was not statistically significant for the retrieved condition.

Microstructural Effects on the Wear Resistance of Co-Cr Implant Alloys

2006 ◽  
Author(s):  
S. Affatato ◽  
W. Leardini ◽  
A. Jedenmalm ◽  
M. Zavalloni ◽  
O. Ruggeri ◽  
...  
Keyword(s):  
Wear Behavior ◽  
Late Complication ◽  
Calf Serum ◽  
Wear Rates ◽  
Metal On Metal ◽  
Microstructural Effects ◽  
Femoral Heads ◽  
Polyethylene Particles ◽  
Implant Alloys ◽  
Different Diameters

Modern metal-on-metal articulation have been proposed to reduce the incidence of osteolysis due to polyethylene particles debris, as a late complication. The tribology of large metal-on-metal articulations allows theoretical advantages with respect to other configurations, especially for the lubrication regime. This study was aimed to compare the wear performances of different diameters of clinically available acetabular metallic components manufactured in a cast cobalt-chrome alloy. To evaluate the influence of the material properties of wear and microstructure, metal-on-metal components were tested in a hip joint simulator for five million cycles with bovine calf serum as lubricant. In particular, three different configurations of metal-on-metal components (28-mm, 36-mm, 54-mm) were tested. After the test all specimens were examined with optical and electronic scanning microscope. A statistical difference were observed among the three groups tested in the run-in and steady-state wear rates, favoring the larger femoral heads. The results of this study indicate that the 54-mm diameter femoral heads prove a better wear behavior than the smaller configurations.

Effects of Environment on the Wear Behavior of P/M Ti-47Al-2Cr-0.2Mo

2018 ◽  
Vol 770 ◽  
pp. 106-115
Author(s):  
Jing Wen Qiu ◽  
Di Pan ◽  
Yong Liu ◽  
Ian Baker ◽  
Wei Dong Zhang
Keyword(s):  
Wear Behavior ◽  
High Stress ◽  
Dry Sliding Wear ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wear Rates ◽  
Disk Material ◽  
Three Body ◽  
Pin On Disk ◽  
Wear Tests

The wear behavior of powder metallurgical Ti-47Al-2Cr-0.2Mo alloy prepared by pre-alloyed powders was investigated using pin-on-disk wear tests in different environments, viz, argon, 4% hydrogen in nitrogen, air and oxygen. The disk material was sinter-hot isostatically pressed, yttria-stabilized zirconia. Lower wear rates were found for the TiAl pins in oxygen-free environments, indicating that oxygen play a key role in the wear rate. In contrast, the presence of molecular hydrogen and moisture have nearly no effect. A combination of X-ray diffraction and energy dispersive X-ray spectroscopy indicated that the abrasive particles present mainly consisted of the zirconia. In addition, zirconia particles were embedded in the worn tips of the TiAl pins and mixed into the tribolayers. The high stress and high contact temperature at the wear surface made the zirconia disk undergo a phase transformation during the dry sliding wear, accompanied by grain pullout, surface uplifting and microcracking. The hard tribolayer with embedded zirconia particles provides some protection against further wear of the TiAl pin. The highly localized, repetitive shear stress during the wear tests may bring about amorphous TiAl in the wear debris. The main wear mechanisms were abrasive wear of two-body and three-body, some delamination and plastic deformation.

The Effect of Motion Path on the Wear Rate of UHMWPE for Orthopaedic Implants

1999 ◽  
Author(s):  
Jeff A. Sprague ◽  
Willard L. Sauer
Keyword(s):  
Wear Rate ◽  
Wear Test ◽  
Axial Rotation ◽  
Wear Testing ◽  
Motion Path ◽  
Orthopaedic Implant ◽  
Wear Rates ◽  
Nonlinear Motion ◽  
Pin On Disk

Abstract The effect of adding a second axis of motion was investigated for pin-on-disk wear testing of ultra-high-molecular-weight polyethylene (UHMWPE) for orthopaedic implant applications. In addition to linear reciprocation of the UHMWPE or metal disk, axial rotation of the metal or UHMWPE pin was conducted. The added rotation reproduces the cross-shear on the UHMWPE surface that is generated in clinically relevant wear simulator tests and in vivo. The wear rates that result from the multi-axis pin-on-disk tests are significantly higher (one to two orders of magnitude) than those seen in the linear-only tests. This supports the findings of other researchers (Bragdon et al., 1996; McKellop, 1995; Walker et al., 1996; Wang et al. 1997) in that the application of nonlinear motion increases the wear of UHMWPE substantially. This is further validated by the comparison of a hip simulator wear test conducted with three axes of motion — rotation, flexion, and abduction — to a test conducted with two axes of motion — rotation and flexion. The absence of the abduction eliminated a significant degree of nonlinear motion (cross-shear) and, consequently, the wear rate was significantly lower than that seen in the test with abduction.

Comparative Study of Wear Behavior of Multilayer Coatings for Human Hip Prosthesis

2015 ◽  
Vol 787 ◽  
pp. 528-533
Author(s):  
M. Kalayarasan ◽  
V. Prabhu Raja ◽  
V. Nithin ◽  
S. Vivinkumar ◽  
M. Vishwaanth
Keyword(s):  
Wear Rate ◽  
Hip Prosthesis ◽  
Wear Behavior ◽  
Multilayer Coating ◽  
Joint Disease ◽  
High Wear Resistance ◽  
Arc Spraying ◽  
High Fatigue ◽  
Artificial Hip Joints ◽  
Term Performance

Artificial hip joints have been implanted throughout the world into patients suffering from disabling hip joint disease, to restore their painless joint function. This means replacing the femoral head and acetabular socket with artificial prosthetic components. In order to obtain artificial implants with enhanced physical, chemical, mechanical, biological and tribological properties resulting in the accelerated self-adaptation of human body and long term performance, it is necessary to combine the advantages of materials with various properties; biocompatibility, bioactivity, excellent corrosion resistance, high fatigue and tensile strength, low modulus of elasticity, coefficient of friction, and high wear resistance. The present work focuses on investigating the wear rate of multi-layer coatings for different combinations in order to reduce the wear rate of the prosthesis. Three different combinations of multilayer coating were deposited by plasma arc spraying technique on titanium. It was found that the multi-layer coating consists of Alumina as a primary coating and Zirconia as the secondary coating provides lower wear rate and higher hardness compared to other combinations which would give optimal performance and thereby increasing its longevity.

The Effects of Sliding Parameters on Dry Wear Characteristics of Ti-6Al-4V Alloy

2015 ◽  
Vol 1115 ◽  
pp. 213-216 ◽  
Author(s):  
Mohammed Baba Ndaliman ◽  
Katsina Christopher Bala ◽  
Ahsan Ali Khan ◽  
Mohammad Yeakub Ali ◽  
Umma Abdullahi ◽  
...  
Keyword(s):  
Wear Rate ◽  
Wear Behavior ◽  
Weight Ratio ◽  
High Strength ◽  
Surface Wear ◽  
Wear Properties ◽  
Wear Rates ◽  
Sliding Motion ◽  
Study Results ◽  
Pin On Disk

Titanium (Ti-6Al-4V) alloy is very attractive for many applications due to its high strength-to-weight ratio and high corrosion resistance. Even then, with these attractive properties, it has poor shear strength and surface wear properties. This study is therefore undertaken to investigate the effect of sliding parameters on the surface wear behavior of Ti-6Al-4V alloy. Pin-like specimens of the alloy were produced and subjected to sliding motion on a pin-on-disk apparatus using different speeds, loads and sliding distances. The surface and specific wear rates of the alloy were evaluated as the main output of the study. Results indicate that the most severe surface wear rate of over 0.008 mm3/sec is experienced under conditions of low disk speed (50 rpm) with high input weight (46.5 N). Higher sliding distance is also found to affect the severity of the surface wear rate. All results of specific wear rates evaluated indicate that Ti-6Al-4V alloy can be classified as a low surface wear resistance material when operated under sliding counterface.

scholarly journals In vivo wear of CAD-CAM composite versus lithium disilicate full coverage first-molar restorations: a pilot study over 2 years

2020 ◽  
Vol 24 (12) ◽  
pp. 4301-4311
Author(s):  
Jan-Frederik Güth ◽  
Kurt Erdelt ◽  
Christine Keul ◽  
Gintare Burian ◽  
Josef Schweiger ◽  
...  
Keyword(s):  
Wear Behavior ◽  
Lithium Disilicate ◽  
Tissue Loss ◽  
Invasive Treatment ◽  
Occlusal Contact ◽  
Wear Rates ◽  
Occlusal Wear ◽  
Cad Cam ◽  
Second Year

Abstract Objectives To present a digital approach to measure and compare material wear behavior of antagonistic first molar restorations made of an experimental CAD/CAM composite (COMP) and lithium disilicate ceramic (LS2) in patients with reconstructed vertical dimension of occlusion (VDO) after generalized hard tissue loss. Methods A total of 12 patients underwent complete full jaw rehabilitation with full occlusal coverage restorations made either of COMP or LS2. The first molar restorations (n = 48) were chosen for wear examination. At annual recall appointments, polyether impressions were taken, and resulting plaster casts were digitalized using a laboratory scanner. Mean observation period was 371 days for first and 769 days for second year. The resulting 96 datasets were analyzed by superimposition of 3-D datasets using an iterative best-fit method. Based on the superimposition data, the wear rates of the occlusal contact areas (OCAs) were calculated. Results For antagonistic restorations made of COMP, the average wear rate was 24.8 ± 13.3 μm/month, while for LS2, it was 9.5 ± 4.3 μm/month in first year, with significant differences (p < 0.0001) between the materials. In second year, monthly wear rates decreased significantly for both materials: COMP (16.2 ± 10.7 μm/month) and LS2 (5.5 ± 3.3 μm/month). Statistical comparison between wear time showed significant differences for both materials: COMP p < 0.037 and LS2 p < 0.001. A logarithmic fit (COMP R2 = 0.081; LS2 R2 = 0.038) of the data was calculated to estimate the wear progression. Significance In patients with reconstructed VDO, restorations made of LS2 show a more stable wear behavior than ones out of experimental CAD/CAM composite. In cases of complete rehabilitation, load bearing CAD/CAM-composite restorations should be critically considered for application due to their occlusal wear behavior. However, when choosing a restorative material, not only the functional occlusal stability should be taken into account but also the prospect of minimally invasive treatment with maximum preservation of natural tooth structures.

Charnley wear model for validation of hip simulators' ball diameter versus polytetrafluoroethylene and polyethylene wear

1997 ◽  
Vol 211 (1) ◽  
pp. 25-36 ◽  
Author(s):  
I C Clarke ◽  
V Good ◽  
L Anissian ◽  
A Gustafson
Keyword(s):  
Femoral Head ◽  
Clinical Data ◽  
Polyethylene Wear ◽  
Test Duration ◽  
Cobalt Chromium ◽  
Wear Model ◽  
Wear Rates ◽  
Ball Diameter ◽  
Relationship Of

Wear rates of polytetrafluoroethylene (PTFE) and polyethylene cups were compared in 9-channel and 12-channel simulators, using serum lubrication and gravimetric techniques for wear assessment. Cobalt-chromium (CoCr) and alumina ceramic femoral heads in 22-42 mm diameter range were used to validate simulator wear rates against clinical data. This was also the first study of three femoral head sizes evaluated concurrently in a simulator (with three replicate specimens) and also the first report in which any wear experiments were repeated. Fluid absorption artefacts were within ± 1 per cent of wear magnitude for PTFE and ± 8 per cent for polyethylene and were corrected for. Wear rates were linear as a function of test duration. Precision within each set of three cups was within ±6 per cent. The wear rates from experiments repeated over 15 months were reproducible to within ± 24 per cent. However, the magnitudes of the simulator wear rates were not clinically accurate, the PTFE wear rates (2843 mm3/106 cycles; 22 mm diameter) were over three times higher than in vivo, the polyethylene 30 to 50 per cent on the low side (23 mm3/106 cycles; 22 mm diameter). Volumetric wear rate increased with respect to size of femoral head and a linearly increasing relationship of 7-8 per cent/mm was evident with respect to femoral head diameter for both PTFE and polyethylene. These data compared well with the clinical data.

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