Lubrication of Hip and Knee Joint Replacements

Biotribology ◽  
2021 ◽  
pp. 33-61
Author(s):  
D. Nečas ◽  
M. Marian ◽  
Y. Sawae
2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 851.1-851
Author(s):  
G. Singh ◽  
M. Sehgal ◽  
A. Mithal

Background:Irreversible joint damage in gout has been linked to a possible increase in knee and hip joint replacements1. In addition, the strong association between gout and osteoarthritis2,3 could also lead to an increased risk of joint replacements in patients with gout. Population-based data from the UK and Taiwan have shown hazard rates of 1.14 and 1.16 respectively for knee replacements in patients with gout compared to age and gender matched controls1. However, there is little national data in the US on clinical and economic burden of joint replacements in patients with gout.Objectives:To evaluate total or partial hip and knee joint replacements in patients with gout in the US and to estimate their economic impactMethods:The Nationwide Inpatient Sample (NIS) is a stratified random sample of all US community hospitals. It is the only US national hospital database with information on all patients, regardless of payer, including persons covered by Medicare, Medicaid, private insurance, and the uninsured. Detailed information including clinical and nonclinical data elements on each hospital stay including International Classification of Diseases (ICD)10 diagnosis and procedure codes, age, gender, length of stay, payer, charges, comorbidities etc. is available. We examined hospitalizations in patients with gout with hip and knee joint replacements in NIS 2018, the most recent year of data.Results:In 2018, there were 914,510 hospitalizations with primary or secondary diagnosis of gout in the US. Of these 43,615 were for joint replacement surgeries (knee (24,840) and hip (18,755)). Patients with knee replacement were on an average 68.5 years old (95% confidence intervals 68.2 years -68.8 years). Patients with hip replacement were slightly older (mean age 70.3 years, 95% confidence intervals 69.8 years -70.7 years). Unlike general population statistics, men formed a majority of these joint replacements (68% for the knee and 72% for the hip). The average charge per hospitalization was $69,279 and $72,944 for knee and hip replacement respectively. The total annual national cost estimate was $3.09 billion, with government insurances (Medicare and Medicaid) responsible for 67% of knee replacement and 70% of hip replacement costs.Conclusion:Joint replacements in gout patients have a large clinical and economic burden in the US. This calls for an increased awareness and management of associated hip and knee arthritis in patients with gout.References:[1]Kuo CF, Chou IJ, See LC, et al. Urate-lowering treatment and risk of total joint replacement in patients with gout. Rheumatology. Dec 1 2018;57(12):2129-2139.[2]Howard RG, Samuels J, Gyftopoulos S, et al. Presence of gout is associated with increased prevalence and severity of knee osteoarthritis among older men: results of a pilot study. Journal of clinical rheumatology: practical reports on rheumatic & musculoskeletal diseases. Mar 2015;21(2):63-71.[3]Roddy E, Zhang W, Doherty M. Are joints affected by gout also affected by osteoarthritis? Annals of the rheumatic diseases. Oct 2007;66(10):1374-1377.Disclosure of Interests:Gurkirpal Singh Shareholder of: Pfizer, Merck, Sanofi, Grant/research support from: Horizon, Maanek Sehgal: None declared, Alka Mithal: None declared.


Author(s):  
T Stewart ◽  
Z M Jin ◽  
D Shaw ◽  
D D Auger ◽  
M Stone ◽  
...  

The tibio-femoral contact area in five current popular total knee joint replacements has been measured using pressure-sensitive film under a normal load of 2.5 kN and at several angles of flexion The corresponding maximum contact pressure has been estimated from the measured contact areas and found to exceed the point at which plastic deformation is expected in the ultra-high molecular weight polyethylene (UHMWPE) component particularly at flexion angles near 90°. The measured contact area and the estimated maximum contact stress have been found to be similar in magnitude for all of the five knee joint replacements tested. A significant difference, however, has been found in maximum contact pressure predicted from linear elasticity analysis for the different knee joints. This indicates that varying amounts of plastic deformation occurred in the polyethylene component in the different knee designs. It is important to know the extent of damage as knees with large amounts of plastic deformation are more likely to suffer low cycle fatigue failure. It is therefore concluded that the measurement of contact areas alone can be misleading in the design of and deformation in total knee joint replacements. It is important to modify geometries to reduce the maximum contact stress as predicted from the linear elasticity analysis, to below the linear elastic limit of the plastic component.


Wear ◽  
1979 ◽  
Vol 52 (2) ◽  
pp. 275-284 ◽  
Author(s):  
P.N. Tandon ◽  
Sunil Jaggi

2007 ◽  
Vol 65 (3) ◽  
pp. 219-225 ◽  
Author(s):  
K. Huotari ◽  
O. Lyytikäinen ◽  
S. Seitsalo

2018 ◽  
Vol 4 (1) ◽  
pp. 18-23 ◽  
Author(s):  
Leiming Gao ◽  
Zikai Hua ◽  
Robert Hewson ◽  
Michael Skipper Andersen ◽  
Zhongmin Jin

Author(s):  
Z M Jin ◽  
D Dowson ◽  
J Fisher

A general elasticity contact theory has been developed, to predict the contact area and the contact pressure in total knee joint replacements with elliptical contacts where the thickness of ultra high molecular weight polyethylene (UHMWPE) is similar or less than the contact half width. The interfacial boundary condition between the UHMWPE component and the underlying metal substrate has been considered to be either perfectly bonded or perfectly unbonded in the model. Poisson's ratio for UHMWPE has been assumed to be 0.3 or 0.4. The effect of the thickness of the UHMWPE layer on the contact area and the contact pressure has been examined. The predictions of the maximum contact pressure and the contact area have been presented in non-dimensional forms and can readily be applied for typical design configurations of current total knee joint replacements. Furthermore, the present results can readily be applied to design considerations for total knee joint replacements to reduce contact stresses within the UHMWPE component.


2021 ◽  
Vol 64 (1) ◽  
pp. E66-E68
Author(s):  
Pascal-André Vendittoli ◽  
Karina Pellei ◽  
Carla Williams ◽  
Claude Laflamme

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