Optimization of Inventory and Distribution for Hip and Knee Joint Replacements via Multistage Stochastic Programming

2019 ◽  
pp. 139-155 ◽  
Author(s):  
Mohammad Pirhooshyaran ◽  
Lawrence V. Snyder
Keyword(s):  
Stochastic Programming ◽  
Knee Joint ◽  
Multistage Stochastic Programming ◽  
Joint Replacements

scholarly journals POS1143 GOUT AND JOINT REPLACEMENTS IN THE US

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 851.1-851
Author(s):  
G. Singh ◽  
M. Sehgal ◽  
A. Mithal
Keyword(s):  
Knee Joint ◽  
Confidence Intervals ◽  
Knee Replacement ◽  
Joint Replacement ◽  
Economic Burden ◽  
Hip Replacement ◽  
Average Charge ◽  
Joint Replacements ◽  
Increased Risk ◽  
The Us

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.

Experimental and Theoretical Study of the Contact Mechanics of Five Total Knee Joint Replacements

1995 ◽  
Vol 209 (4) ◽  
pp. 225-231 ◽  
Author(s):  
T Stewart ◽  
Z M Jin ◽  
D Shaw ◽  
D D Auger ◽  
M Stone ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Knee Joint ◽  
Contact Pressure ◽  
Contact Stress ◽  
Linear Elasticity ◽  
Contact Area ◽  
Elasticity Analysis ◽  
Joint Replacements ◽  
Total Knee ◽  
Maximum Contact

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.

scholarly journals Is there a risk of permanent renal dysfunction after primary total hip and knee joint replacements?

2016 ◽  
Vol 11 (1) ◽  
Author(s):  
Basim Kamil Hassan ◽  
Ram Benny Christian Dessau ◽  
Arne Sahlström
Keyword(s):  
Knee Joint ◽  
Renal Dysfunction ◽  
Joint Replacements ◽  
Total Hip

A model for the lubrication mechanism in knee joint replacements

Wear ◽  
1979 ◽  
Vol 52 (2) ◽  
pp. 275-284 ◽  
Author(s):  
P.N. Tandon ◽  
Sunil Jaggi
Keyword(s):  
Knee Joint ◽  
Lubrication Mechanism ◽  
Joint Replacements

scholarly journals An Inventory-Theory-Based Inexact Multistage Stochastic Programming Model for Water Resources Management

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
M. Q. Suo ◽  
Y. P. Li ◽  
G. H. Huang ◽  
Y. R. Fan ◽  
Z. Li
Keyword(s):  
Water Resources ◽  
Stochastic Programming ◽  
Water Resources Management ◽  
Programming Model ◽  
Water Shortage ◽  
Multistage Stochastic Programming ◽  
Dynamic Features ◽  
Inventory Theory ◽  
Resources Management ◽  
Water Resources Systems

An inventory-theory-based inexact multistage stochastic programming (IB-IMSP) method is developed for planning water resources systems under uncertainty. The IB-IMSP is based on inexact multistage stochastic programming and inventory theory. The IB-IMSP cannot only effectively handle system uncertainties represented as probability density functions and discrete intervals but also efficiently reflect dynamic features of system conditions under different flow levels within a multistage context. Moreover, it can provide reasonable transferring schemes (i.e., the amount and batch of transferring as well as the corresponding transferring period) associated with various flow scenarios for solving water shortage problems. The applicability of the proposed IB-IMSP is demonstrated by a case study of planning water resources management. The solutions obtained are helpful for decision makers in not only identifying different transferring schemes when the promised water is not met, but also making decisions of water allocation associated with different economic objectives.

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