Local Head Roughening as a Factor Contributing to Variability of Total Hip Wear: A Finite Element Analysis

2002 ◽  
Vol 124 (6) ◽  
pp. 691-698 ◽  
Author(s):  
Thomas D. Brown ◽  
Kristofer J. Stewart ◽  
John C. Nieman ◽  
Douglas R. Pedersen ◽  
John J. Callaghan
Keyword(s):  
Wear Rate ◽  
Adhesive Wear ◽  
Polyethylene Wear ◽  
Bearing Surface ◽  
Third Body ◽  
Element Analysis ◽  
Wear Factor ◽  
Total Hip ◽  
Key Factor ◽  
Sliding Distance

Large inter-patient variability in wear rate and wear direction have been a ubiquitous attribute of total hip arthroplasty (THA) cohorts. Since patients at the high end of the wear spectrum are of particular concern for osteolysis and loosening, it is important to understand why some individuals experience wear at a rate far in excess of their cohort average. An established computational model of polyethylene wear was used to test the hypothesis that, other factors being equal, clinically typical variability in regions of localized femoral head roughening could account for much of the variability observed clinically in both wear magnitude and wear direction. The model implemented the Archard abrasive/adhesive wear relationship, which incorporates contact stress, sliding distance, and (implicitly) bearing surface tribology. Systematic trials were conducted to explore the influences of head roughening severity, roughened area size, and roughened area location. The results showed that, given the postulated wear factor elevations, head roughening variability (conservatively) typical of retrieval specimens led to approximately a 30° variation in wear direction, and approximately a 7-fold variation in volumetric wear rate. Since these data show that randomness in head scratching can account for otherwise-difficult-to-explain variations in wear direction and wear rate, third-body debris may be a key factor causing excessive wear in the most problematic subset of the THA population.

ADHESIVE WEAR AND FRICTIONAL BEHAVIOR OF MULTILAYERED POLYESTER COMPOSITE BASED ON BETELNUT FIBER MATS UNDER WET CONTACT CONDITIONS

2009 ◽  
Vol 16 (03) ◽  
pp. 407-414 ◽  
Author(s):  
B. F. YOUSIF ◽  
ALVIN DEVADAS ◽  
TALAL F. YUSAF
Keyword(s):  
Stainless Steel ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Adhesive Wear ◽  
Specific Wear Rate ◽  
Wear Performance ◽  
Fiber Mats ◽  
Polyester Composite ◽  
Sliding Distance ◽  
Wet Contact

In the current study, a multilayered polyester composite based on betelnut fiber mats is fabricated. The adhesive wear and frictional performance of the composite was studied against a smooth stainless steel at different sliding distances (0–6.72 km) and applied loads (20–200 N) at 2.8 m/s sliding velocity. Variations in specific wear rate and friction coefficient were evaluated at two different orientations of fiber mat; namely parallel (P–O) and normal (N–O). Results obtained were presented against sliding distance. The worn surfaces of the composite were studied using an optical microscope. The effect of the composite sliding on the stainless steel counterface roughness was investigated. The results revealed that the wear performance of betelnut fiber reinforced polyester (BFRP) composite under wet contact condition was highly dependent on test parameters and fiber mat orientation. The specific wear rate performance for each orientation showed an inverse relationship to sliding distance. BFRP composite in N–O exhibited better wear performance compared with P–O. However, the friction coefficient in N–O was higher than that in P–O at lower range of applied load. The predominant wear mechanism was debonding of fiber with no pullout or ploughing. Moreover, at higher applied loads, micro- and macrocracking and fracture were observed in the resinous region.

Computational modelling of polyethylene wear and creep in total hip joint replacements: Effect of the bearing clearance and diameter

2012 ◽  
Vol 226 (6) ◽  
pp. 552-563 ◽  
Author(s):  
Feng Liu ◽  
John Fisher ◽  
Zhongmin Jin
Keyword(s):  
Wear Rate ◽  
Hip Joint ◽  
Contact Area ◽  
Polyethylene Wear ◽  
Computational Modelling ◽  
Total Hip ◽  
Bearing Clearance ◽  
Wear Modelling ◽  
Wear Law ◽  
Hip Joint Replacements

Computational wear modelling has been improved using a contact area dependent wear law for the conventional ultra-high molecular weight polyethylene used in total hip joint bearings. The current designs of polyethylene bearings tend to use larger diameter heads to achieve improved motion function for patients in clinical practice, but the wear of the bearing may also increase due to the increase in contact area associated with the larger bearings. Additionally, bearing clearance, which is the difference in diameter or radius between the cup and head bearing surfaces, may also play an important role in affecting the wear. This study particularly investigates the effect of bearing clearance on polyethylene wear, for different femoral head diameters, through a parametric study using the computational modelling method. The effect of creep of polyethylene on the contact area and wear was considered, since polyethylene creep can account for a significantly large proportion of volumetric change, particularly during the initial loading stage, and an increase in the contact area. The predicted wear rate was found to be comparable to the experimental wear rate found in independent simulator tests. The polyethylene bearing with decreased bearing clearances led to a substantial increase in the wear rate, particularly when combined with large diameters.

scholarly journals Effects of Surface Modification and Bulk Geometry on the Biotribological Behavior of Cross-Linked Polyethylene: Wear Testing and Finite Element Analysis

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Kenichi Watanabe ◽  
Masayuki Kyomoto ◽  
Kenichi Saiga ◽  
Shuji Taketomi ◽  
Hiroshi Inui ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Creep Deformation ◽  
Polyethylene Wear ◽  
Wear Testing ◽  
Von Mises Stress ◽  
Cross Linking ◽  
Bearing Surface ◽  
Cobalt Chromium ◽  
Element Analysis

The wear and creep deformation resistances of polymeric orthopedic bearing materials are both important for extending their longevity. In this study, we evaluated the wear and creep deformation resistances, including backside damage, of different polyethylene (PE) materials, namely, conventional PE, cross-linked PE (CLPE), and poly(2-methacryloyloxyethyl phosphorylcholine)- (PMPC-) grafted CLPE, through wear tests and finite element analysis. The gravimetric and volumetric degrees of wear of disks (3 or 6 mm in thickness) of these materials against a cobalt-chromium-molybdenum alloy pin were examined using a multidirectional pin-on-disk tester. Cross-linking and PMPC grafting decreased the gravimetric wear of the PE disks significantly. The volumetric wear at the bearing surface and the volumetric penetration in the backside of the 3-mm thick PE disk were higher than those of the 6-mm thick PE disk, regardless of the bearing material. The geometrical changes induced in the PE disks consisted of creep, because the calculated internal von Mises stress at the bearing side of all disks and that at the backside of the 3-mm thick disks exceeded their actual yield strengths. A highly hydrated bearing surface layer, formed by PMPC grafting, and a cross-linking-strengthened substrate of adequate thickness are essential for increasing the wear and creep deformation resistances.

scholarly journals Finite element analysis of polyethylene wear in total hip replacement: A literature review

2019 ◽  
Vol 233 (11) ◽  
pp. 1067-1088 ◽  
Author(s):  
Lin Wang ◽  
Graham Isaac ◽  
Ruth Wilcox ◽  
Alison Jones ◽  
Jonathan Thompson
Keyword(s):  
Finite Element ◽  
Literature Review ◽  
Hip Replacement ◽  
Material Selection ◽  
Polyethylene Wear ◽  
Element Analysis ◽  
Total Hip ◽  
Total Hip Replacements ◽  
Hip Replacements ◽  
Modelling Techniques

Evaluation and prediction of wear play a key role in product design and material selection of total hip replacements, because wear debris is one of the main causes of loosening and failure. Multifactorial clinical or laboratory studies are high cost and require unfeasible timeframes for implant development. Simulation using finite element methods is an efficient and inexpensive alternative to predict wear and pre-screen various parameters. This article presents a comprehensive literature review of the state-of-the-art finite element modelling techniques that have been applied to evaluate wear in polyethylene hip replacement components. A number of knowledge gaps are identified including the need to develop appropriate wear coefficients and the analysis of daily living activities.

Contact Temperature and Its Effects in an Oscillatory Sliding Contact

1989 ◽  
Vol 111 (1) ◽  
pp. 63-69 ◽  
Author(s):  
F. E. Kennedy ◽  
S. C. Cullen ◽  
J. M. Leroy
Keyword(s):  
Wear Rate ◽  
Polyethylene Wear ◽  
Contact Temperature ◽  
Element Analysis ◽  
Wear Rates ◽  
Transfer Films ◽  
Model Predictions ◽  
The Relationship ◽  
Ultra High Molecular Weight ◽  
Good Agreement

The relationship between contact temperature, friction coefficient, and wear rate was studied here for the case of dry sliding between pin and flat in small amplitude oscillatory motion. In the first part of the study, infrared radiation pyrometry and finite element analysis techniques were used to measure and model surface temperatures in an oscillatory contact. Good agreement was achieved between model predictions and experimental measurements. The model was then applied to an oscillating contact between an ultra-high molecular weight polyethylene pin and a rough stainless steel flat. Temperature predictions for that case were correlated with measured friction coefficients and wear rates. It was found that the polyethylene wear rate decreased as the contact temperature increased. The uniformity and thickness of the transfer films which formed on both counterface and polymer pin were found to be affected by contact temperature. Transfer film behavior was deemed responsible for the influence of contact temperature on wear rate.

The Potential of Using Betelnut Fibres for Tribo-Polyester Composites Considering Three Different Orientations

2008 ◽  
Author(s):  
B. F. Yousif ◽  
Nirmal Singh Gill ◽  
Saijod T. W. Lau ◽  
Alvin Devadas
Keyword(s):  
Wear Rate ◽  
Adhesive Wear ◽  
Specific Wear Rate ◽  
Frictional Behavior ◽  
Pull Out ◽  
Micro Cracks ◽  
Wear And Friction ◽  
Polished Stainless Steel ◽  
Polyester Composites ◽  
Sliding Distance

This paper presents an attempt to use betelnut fibres as reinforcement for tribo-polyester composites in bearing applications. The composite was fabricated using the hand lay-up technique, and contains 15 layers of randomly distributed chopped fibres and 17 layers of polyester. The adhesive wear and frictional behavior of the composites were studied against a polished stainless steel counterface using block-on-disc (BOD) machine at different applied loads (5–30N) and sliding distance (0–7km). In addition to that, the orientation of the fibre layers with respect to the sliding direction of the counterface was considered, i.e. parallel (P-O), anti-parallel (AP-O) and normal (N-O). Studies on worn surfaces, using a scanning electron microscope (SEM), and roughness profiles of the composite and counterface assisted to explain the results. As a result of this work, it was found that applied load has less effect on the specific wear rate and friction coefficient of the composite especially in P-O and AP-O. Meanwhile, in both orientations (P-O and AP-O), the steady state of specific wear rate was reached after 5 km sliding distance. On the other hand, the composite behaved differently in N-O, where the wear and friction increased when the load and sliding distance increased. This was due to the poor support of the fibres in that orientation, where delamination, pull out and breakage in the fibres were observed. In P-O and AP-O, the wear mechanism was predominated by plastic deformation and micro-cracks.

scholarly journals THE CERAMIC MODULAR HEAD IMPROVEMENT IN THE DESIGN OF A TOTAL HIP REPLACEMENT

2021 ◽  
Vol 19 (1) ◽  
pp. 067
Author(s):  
Vladimir Pakhaliuk ◽  
Aleksandr Poliakov ◽  
Ivan Fedotov
Keyword(s):  
Hip Replacement ◽  
Friction Pair ◽  
Low Cost ◽  
Bearing Surface ◽  
Zirconia Ceramics ◽  
Element Analysis ◽  
Hip Joint Replacement ◽  
Total Hip ◽  
Brazed Joint ◽  
First Time

For the first time, a design of a modular ceramic ball head of a total hip joint replacement (THR) friction pair has been developed, which has the properties of a metal in conjunction with the stem neck and the properties of a ceramics on bearing surface of the pair. This is achieved by creating a low-cost, low-toxic, durable fixed connection of the head made of alumina or zirconia ceramics and the titanium-based alloy sleeve to obtain a brazed joint that is efficient in human synovial fluid. With the help of finite element analysis, a quantitative assessment of the strength and rigidity of the proposed head design was performed and its use in modern hip arthroplasty was indicated. The approbation of the proposed design solutions for creating a THR ceramic head with a titanium-based alloy sleeve brazed was carried out.

scholarly journals IMPACT OF VARIOUS FACTORS ON THE POLYETHYLENE WEAR RATE IN TOTAL HIP ARTHROPLASTY

2018 ◽  
Vol 24 (1) ◽  
pp. 18-28 ◽  
Author(s):  
R. M. Tikhilov ◽  
M. I. Shubnyakov ◽  
A. A. Boyarov ◽  
A. O. Denisov ◽  
I. I. Shubnyakov
Keyword(s):  
Total Hip Arthroplasty ◽  
Wear Rate ◽  
Hip Arthroplasty ◽  
Polyethylene Wear ◽  
Total Hip
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