117 Numerical Analysis of the Talus with the Lateral Ligament Injury using 3-D Finite Elements Method

2001 ◽  
Vol 2001 (0) ◽  
pp. 41-42
Author(s):  
Kensaku KAWAKAMI ◽  
Toshiaki HARA
Keyword(s):  
Numerical Analysis ◽  
Finite Elements ◽  
Finite Elements Method ◽  
Ligament Injury ◽  
Lateral Ligament ◽  
Lateral Ligament Injury

scholarly journals Influence of foundation settlements in load redistribution on columns in a monitoring construction - Case Study

2010 ◽  
Vol 3 (3) ◽  
pp. 346-356 ◽  
Author(s):  
G. Savaris ◽  
P. H. Hallak ◽  
P. C. A. Maia
Keyword(s):  
Numerical Analysis ◽  
Numerical Model ◽  
Finite Elements ◽  
Load Distribution ◽  
Numerical Models ◽  
Normal Load ◽  
Finite Elements Method ◽  
Load Redistribution

The objective of this article is to present the results obtained in a study on the interaction between the behavior of the structure and the foundation settlements and verify the influence of normal load distribution on the columns. In this mechanism, known as structure soil interaction (SSI), as the building is constructed, a transfer of loads occurs from the columns which tend to settle more to those that tend to settle less. The study was conducted in a building which had its settlements monitored from the beginning of construction. For this purpose, a linear tridimensional numerical model was constructed and numerical analysis was performed, using the finite elements method. In these analyses, numerical models corre- sponding to the execution of each floor were used, considering the settlements measured in each stage of the construction. The results of analy- ses showed that the effect of SSI are significant for calculating the normal efforts on the columns, particularly on those located in the first floors.

scholarly journals Numerical analysis of stress distribution generated in spherical polyethylene inserts by knee joint endoprotheses’ sleds

2019 ◽  
Vol 21 (2) ◽  
pp. 1-5
Author(s):  
Marcin Nabrdalik ◽  
Michał Sobociński
Keyword(s):  
Numerical Analysis ◽  
Finite Elements ◽  
Stress Distribution ◽  
Knee Joint ◽  
Titanium Alloys ◽  
Numerical Method ◽  
Ti6al4v Alloy ◽  
Finite Elements Method ◽  
Weak Points ◽  
Metal Materials

Abstract The paper presents analysis of stress distribution in the friction node of knee joint endoprosthesis where sleds are made of various titanium alloys and CoCrMo cooperate with spherical polyethylene inserts. Currently used titanium alloys consists of Nb, Ta, Zr or Mo and with lesser value of Young’s modulus than Ti6Al4V alloy, or steel CoCrMo, which significantly varies from other metal materials. The obtained results make it possible to indicate the “weak points” of the accepted solution, and thus counteract the subsequent effects resulting from premature wear of endoprosthesis elements. The analysis was conducted with numerical method of ADINA System 8.6. The Finite Elements Method allowed to compute and present stress distribution quickly in all elements of the model.

scholarly journals Stress roentogenogram for the lateral ligament injury of the ankle.

1984 ◽  
Vol 32 (4) ◽  
pp. 1184-1187
Author(s):  
M. Fujita ◽  
S. M. Yoh ◽  
T. Norimatsu ◽  
R. Suzuki
Keyword(s):  
Ligament Injury ◽  
Lateral Ligament ◽  
Lateral Ligament Injury

scholarly journals The finite element method in the analysis of the stress and strain distribution in polyethylene elements of hip and knee joints endoprostheses

2019 ◽  
Vol 254 ◽  
pp. 02025
Author(s):  
Marcin Nabrdalik ◽  
Michał Sobociński
Keyword(s):  
Numerical Analysis ◽  
Finite Elements ◽  
Finite Elements Method ◽  
Knee Joints ◽  
Stress And Strain ◽  
The Finite Element Method ◽  
Artificial Joints ◽  
Material Fatigue ◽  
Weak Points ◽  
Stress And Strain Distribution

The paper presents the numerical analysis of stress and strain occurring in the most wearable parts of hip and knee joints endoprostheses. The complexity of the processes taking place in both, natural and artificial joints, makes it necessary to conduct the analysis on the 3D model based on already existing mathematical models. Most of the mechanical failures in alloplasty are caused by material fatigue. To cut down the risk of it, we can either increase the fatigue resistance of the material or decrease the load strain. It is extremelly important to indicate the areas where damage or premature wear may occur. The Finite Elements Method makes it possible to calculate the stress and strain in particular elements of the tested models. All presented numerical calculations define quality conclusions concerning the influence of some parameters of endoprostheses on the values of stress and strain that are formed in polyethylene parts of endoprotheses of hip and knee joints. The obtained results help to reveal “weak points” in examined models and thus, counteract the subsequent effects resulting from premature wear of endoprosthesis elements. The numerical analysis was performed basing on the finite elements method using Autodesk Simulation Mechanical 2017 software and the ADINA 7.5.1.

scholarly journals Location and Morphology of Acute Lateral Ligament Injury of the Ankle

2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0031
Author(s):  
Hideo Noguchi
Keyword(s):  
Ankle Instability ◽  
Surgical Reconstruction ◽  
Ligament Injury ◽  
Lateral Ligament ◽  
Ligament Injuries ◽  
Ligament Repair ◽  
Reconstruction Procedure ◽  
Side Body ◽  
Lateral Ligament Injury ◽  
Almost All

Category: Ankle, Sports, Trauma Introduction/Purpose: Acute ankle ligament injuries are usually treated non-operatively, even if the injury is severe. However, when chronic ankle instability is symptomatic, operative treatment is required. When planning local repair, the condition of the remaining ligament is important. We surgically treated acute severe lateral ligament injuries in 103 ankles and investigated the locations of the injuries in the anterior talofibular (ATF) and calcaneofibular (CF) ligaments, subdividing each into three parts. This paper should facilitate more precise planning of the surgical reconstruction procedure. Methods: From 2006 to 2014, 1,042 patients visited our outpatient clinic with a diagnosis of acute lateral ligament injury of the ankle. In total, 103 feet underwent surgical treatment and the locations of the ATF and CF ligament ruptures were investigated. The rupture location in the ATF ligament was subclassified as fibular side, body, or talar side, while for the CF ligament it was classified as fibular side, body, or calcaneal side. Results: The ATF ligament was ruptured on the fibular side in 38 feet (36.9%), body in 30 feet (29.1%), and talar side in 35 feet (34.0%). The CF ligament was ruptured on the fibular side in 15 feet (14.6%), body in 26 feet (25.2%), and calcaneal side in 62 feet (60.2%). Conclusion: Almost all surgical reports on lateral ligament reconstruction procedures (Brostrom et al.) describe ATF ligament repair and advancement on the fibular side, although only one-third of the ligaments were injured on the fibular side in our series. About two-thirds of the CF ligaments had damage to the calcaneal side structure of the entheses. When CF ligament repair is needed, surgeons should be aware of our finding that this ligament was ruptured at the fibular attachment in only 15% of cases, and on the calcaneal side in 60%. This knowledge should lead to better results of surgical reconstruction.

scholarly journals The Broken “Ring of Fire”: A New Radiological Sign as Predictor of Syndesmosis Injury?

2017 ◽  
Vol 5 (3) ◽  
pp. 232596711769506 ◽  
Author(s):  
James Calder ◽  
Adam Mitchell ◽  
Adam Lomax ◽  
Moez S. Ballal ◽  
John Grice ◽  
...  
Keyword(s):  
Ankle Joint ◽  
Distal Tibia ◽  
Interosseous Membrane ◽  
Ligament Injury ◽  
Lateral Ligament ◽  
Ankle Sprains ◽  
Radiological Sign ◽  
Syndesmosis Injury ◽  
Significant Difference ◽  
Lateral Ligament Injury

Background: Subcircumferential periosteal edema above the ankle joint is frequently present on magnetic resonance imaging (MRI) with syndesmosis injuries but has not been previously reported. Fluid height within the interosseous membrane also has not previously been shown to be associated with syndesmosis injury severity. Purpose: To investigate whether a new sign on MRI and measurement of the length of fluid within the interosseous membrane above the ankle may be used to enable identification of a syndesmosis injury and allow differentiation from lateral ligament injury. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Three groups of patients (those with an isolated syndesmosis injury [SI group], isolated lateral ligament injury [LLI group], and no injury [NI group]) who had an ankle MRI for another reason were identified from a patient notes database and the MRI scans retrieved. The scans were anonymized and independently assessed by 8 clinicians (surgeons and radiologists) who were blinded to the diagnosis. The maximum length of fluid above the ankle within the intraosseous membrane was measured for each patient. The presence or absence of distal anterior, lateral, and posterior tibial periosteal edema was recorded (broken “ring of fire”). Results: Measurement of the length of fluid above the ankle had excellent intraobserver reliability (intraclass correlation coefficient, 0.97; 95% CI, 0.93-0.99) but poor interobserver reliability. Fluid extended higher in both the LLI group ( P = .0043) and SI group ( P = .0058) than the NI group, but there was no significant difference between the LLI and SI groups ( P = .3735), indicating that this measurement cannot differentiate between the injuries. The presence of the broken “ring of fire” around the distal tibia was significantly more frequent in the SI group when compared with both LLI and NI groups ( P < .00001). The sensitivity of this sign is 49%, but when present, this sign has a 98% specificity for syndesmosis injury. Conclusion: The presence of tibial subcircumferential periosteal edema 4 to 6 cm above the ankle joint (the “ring of fire”) is highly suggestive of a syndesmosis injury. This new radiological sign can assist with early identification of such injuries. The measurement of height of fluid above the ankle within the interosseous membrane is variable and cannot differentiate severe ankle sprains from high ankle sprains involving the syndesmosis.

Prediction of Rail Profile Wear with the Increase of Vehicle Speed

2013 ◽  
Vol 716 ◽  
pp. 659-662
Author(s):  
Dong Hyong Lee ◽  
Jeong Won Seo ◽  
Seok Jin Kwon ◽  
Ha Young Choi
Keyword(s):  
Numerical Analysis ◽  
Finite Elements ◽  
Boundary Conditions ◽  
Rolling Contact ◽  
Finite Elements Method ◽  
Vehicle Speed ◽  
Two Dimensional ◽  
Contact Wear ◽  
Rail Wear ◽  
Finite Elements Model

A method to simulate rolling contact wear in a rail surface was developed using the finite elements method and numerical analysis. A two-dimensional finite elements model was used in order to reduce the calculation time and boundary conditions to prevent excessive deformation of a wheel and a rail were applied. A numerical analysis of rail wear at rolling contact was predicted using the Archards equation. In addition, the characteristics of rail wear with the increasing speed of vehicle were analyzed. Results show that there was not a large difference in the depths of wear on the rail head with increasing vehicle speed, but the wear on the rail gauge corner increased with increasing vehicle speed.

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