Biomechanical Evaluation of the Impact of Different Weight Loading Conditions on the Mechanical Environment of the Hip Joint Endoprosthesis

2018 ◽  
pp. 691-696
Author(s):  
Ioannis-Ilias K. Farmakis ◽  
Vassiliki T. Potsika ◽  
Emilios Pakos ◽  
Dimitrios I. Fotiadis
Keyword(s):  
Hip Joint ◽  
Loading Conditions ◽  
Mechanical Environment ◽  
Hip Joint Endoprosthesis ◽  
Biomechanical Evaluation ◽  
The Impact ◽  
Weight Loading

A biomechanical study of the effect of weight loading conditions on the mechanical environment of the hip joint endoprosthesis

2019 ◽  
Vol 70 ◽  
pp. 197-202
Author(s):  
Ioannis-Ilias K. Farmakis ◽  
Vassiliki T. Potsika ◽  
Andreas-Foivos Smyris ◽  
Ioannis D. Gelalis ◽  
Dimitrios I. Fotiadis ◽  
...  
Keyword(s):  
Hip Joint ◽  
Biomechanical Study ◽  
Loading Conditions ◽  
Mechanical Environment ◽  
Hip Joint Endoprosthesis ◽  
Weight Loading

scholarly journals Study of Contact Pressures in Total Hip Replacement

2020 ◽  
Author(s):  
Myron Czerniec ◽  
Jarosław Zubrzycki
Keyword(s):  
Contact Pressure ◽  
Hip Joint ◽  
Correct Selection ◽  
Radial Clearance ◽  
Total Hip ◽  
Metal Head ◽  
Hip Joint Endoprosthesis ◽  
Joint Load ◽  
The Impact ◽  
Maximum Contact

Total hip arthroplasty is a complex procedure. The achievements of implantology enabled the development of a faithful representation of hip joint physiology as well as the production of materials that can successfully replace damaged natural tissues. A very important issue is the correct selection of the geometry of the endoprosthesis adequate to the load of the joint. Materials used for endoprosthesis are a metal head and a polymer cup (e.g. PE-UHMW). The main interactions in the endoprosthesis are friction and surface pressure, which must be limited, exceeding them causes the destruction of the biomechanical system - plastic deformation of the polymer and the formation of too large and unacceptable radial clearances. Based on the author's developed calculation method of hip joint endoprosthesis contact parameters, the impact on maximum contact pressure and the angle of contact of the joint load was estimated depending on the diameter of the endoprosthesis and radial clearance. The correctness of changing the values of maximum contact pressure from the mentioned parameters was determined. Correspondingly: an increase in joint load causes a linear increase in the maximum contact pressure; increasing the diameter of the endoprosthesis head - their non-linear decrease, and increasing radial clearance - their increase

Stress Analysis of the Hip Joint Endoprosthesis Ceramic Head for Different Values of Shape Deviations

2014 ◽  
Vol 936 ◽  
pp. 770-775 ◽  
Author(s):  
Vladimír Fuis ◽  
Premysl Janicek
Keyword(s):  
Tensile Stress ◽  
Hip Joint ◽  
Computational Modelling ◽  
Ceramic Head ◽  
Weakest Link ◽  
Shape Deviations ◽  
Hip Joint Endoprosthesis ◽  
Link Theory ◽  
Conical Surfaces ◽  
The Impact

The paper deals with the problems of ceramic head of hip joint endoprosthesis destructions, and with assessing the impact of shape deviations of conical surfaces on the tensile stress under ISO 7206-5 loading. The failure of the hip joint endoprosthesis ceramic head has always traumatic consequences for the patient, since a part of or even the whole endoprosthesis has to be reoperated. Hence, it is desired to reduce the number of implant re-operations to the minimum. Therefore the computational modelling of the stress of the head was realised. The shape deviations of the ideal contact cone areas of the head and stem are parameters that significantly influence the tensile stress in the head and its reliability. The assumed shape deviations of the head’s and stem’s cones are macro shape deviations (different cone taper) and micro shape deviations (unevennes) measured using the IMS-UMPIRE equipment. The stress state in the ceramic heads was solved using the FEM and head’s failure probability is based on the Weibull weakest link theory [4, 5 and 9].

scholarly journals Electric Vehicles in Jordan: Challenges and Limitations

2021 ◽  
Vol 13 (6) ◽  
pp. 3199
Author(s):  
Laith Shalalfeh ◽  
Ashraf AlShalalfeh ◽  
Khaled Alkaradsheh ◽  
Mahmoud Alhamarneh ◽  
Ahmad Bashaireh
Keyword(s):  
Electric Vehicles ◽  
Distribution System ◽  
Distribution Systems ◽  
Environmental Benefits ◽  
System Stability ◽  
Loading Conditions ◽  
Stability Margins ◽  
High Penetration ◽  
Node Distribution ◽  
The Impact

An increasing number of electric vehicles (EVs) are replacing gasoline vehicles in the automobile market due to the economic and environmental benefits. The high penetration of EVs is one of the main challenges in the future smart grid. As a result of EV charging, an excessive overloading is expected in different elements of the power system, especially at the distribution level. In this paper, we evaluate the impact of EVs on the distribution system under three loading conditions (light, intermediate, and full). For each case, we estimate the maximum number of EVs that can be charged simultaneously before reaching different system limitations, including the undervoltage, overcurrent, and transformer capacity limit. Finally, we use the 19-node distribution system to study these limitations under different loading conditions. The 19-node system is one of the typical distribution systems in Jordan. Our work estimates the upper limit of the possible EV penetration before reaching the system stability margins.

scholarly journals Can Optimizing the Mechanical Environment Deliver a Clinically Significant Reduction in Fracture Healing Time?

Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 691
Author(s):  
Jan Barcik ◽  
Devakara R. Epari
Keyword(s):  
Fracture Healing ◽  
Bone Healing ◽  
Mechanical Stimulation ◽  
Callus Formation ◽  
Weight Bearing ◽  
Healing Process ◽  
Healing Time ◽  
Mechanical Environment ◽  
Clinically Significant ◽  
The Impact

The impact of the local mechanical environment in the fracture gap on the bone healing process has been extensively investigated. Whilst it is widely accepted that mechanical stimulation is integral to callus formation and secondary bone healing, treatment strategies that aim to harness that potential are rare. In fact, the current clinical practice with an initially partial or non-weight-bearing approach appears to contradict the findings from animal experiments that early mechanical stimulation is critical. Therefore, we posed the question as to whether optimizing the mechanical environment over the course of healing can deliver a clinically significant reduction in fracture healing time. In reviewing the evidence from pre-clinical studies that investigate the influence of mechanics on bone healing, we formulate a hypothesis for the stimulation protocol which has the potential to shorten healing time. The protocol involves confining stimulation predominantly to the proliferative phase of healing and including adequate rest periods between applications of stimulation.

ANALYSIS OF CONTACT PRESSURE BETWEEN THE PARTS OF TOTAL HIP JOINT ENDOPROSTHESIS WITH SHAPE DEVIATIONS

2007 ◽  
Vol 40 ◽  
pp. S558 ◽  
Author(s):  
V. Fuis ◽  
T. Návrat ◽  
P. Hlavon ◽  
M. Koukal ◽  
M. Houfek
Keyword(s):  
Contact Pressure ◽  
Hip Joint ◽  
Total Hip ◽  
Shape Deviations ◽  
Hip Joint Endoprosthesis

Biomechanical evaluation of artificial hip joint stem with Young's modulus gradation

2021 ◽  
Vol 2021.74 (0) ◽  
pp. C52
Author(s):  
Ryosuke NAKAI ◽  
Kiyohide OCHIAI ◽  
Motoki WASA ◽  
Shuji HANADA ◽  
Etsuo CHOSA ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Hip Joint ◽  
Young's Modulus ◽  
Artificial Hip Joint ◽  
Artificial Hip ◽  
Biomechanical Evaluation

scholarly journals Evaluating the Impact and Norming the Parameters of Partially Regular Texture on the Surface of the Articulating Ball Head in a Total Hip Joint Prosthesis

2016 ◽  
Vol 11 (4) ◽  
pp. 527-539 ◽  
Author(s):  
Vladimir Pakhaliuk ◽  
Alexander Polyakov ◽  
Mikhail Kalinin ◽  
Sergey Bratan
Keyword(s):  
Hip Joint ◽  
Joint Prosthesis ◽  
Total Hip ◽  
The Impact ◽  
Regular Texture

scholarly journals Mechanical frustration of phase separation in the cell nucleus by chromatin

2020 ◽  
Author(s):  
Yaojun Zhang ◽  
Daniel S.W. Lee ◽  
Yigal Meir ◽  
Clifford P. Brangwynne ◽  
Ned S. Wingreen
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Cell Nucleus ◽  
Mechanical Environment ◽  
Coarsening Dynamics ◽  
The Impact ◽  
Droplet Phase ◽  
Liquid Liquid Phase Separation ◽  
Fundamental Mechanism

Liquid-liquid phase separation is a fundamental mechanism underlying subcellular organization. Motivated by the striking observation that optogenetically-generated droplets in the nucleus display suppressed coarsening dynamics, we study the impact of chromatin mechanics on droplet phase separation. We combine theory and simulation to show that crosslinked chromatin can mechanically suppress droplets’ coalescence and ripening, as well as quantitatively control their number, size, and placement. Our results highlight the role of the subcellular mechanical environment on condensate regulation.

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