Finite element model of a novel short stemmed total hip arthroplasty implant developed from cross sectional CT scans

Permanent fixation of a cementless total hip arthroplasty requires bone ingrowth into the femoral and acetabular components. Early micromotion at the acetabular cup/bone interface can preclude ingrowth threatening long term fixation. To better characterize micromotion of the interface under loading conditions, an experimental and finite element (FE) study was undertaken. In this study cadaver hemi-pelvises were implanted with cementless acetabular cups and subjected to cyclical axial load and torque. Detailed finite element model, validated with experimental results, was developed to further analyze the conditions affecting the initial stability and loosening of the interface for different loading conditions.

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Study of Micromotion in Modular Acetabular Components During Gait and Subluxation: A Finite Element Investigation

Journal of Biomechanical Engineering ◽

10.1115/1.2898715 ◽

2008 ◽

Vol 130 (2) ◽

Cited By ~ 8

Author(s):

F. Amirouche ◽

F. Romero ◽

M. Gonzalez ◽

L. Aram

Keyword(s):

Finite Element ◽

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Gait Cycle ◽

Polyethylene Wear ◽

Element Model ◽

Element Analysis ◽

Total Hip ◽

Normal Gait ◽

Acetabular Components

Polyethylene wear after total hip arthroplasty may occur as a result of normal gait and as a result of subluxation and relocation with impact. Relocation of a subluxed hip may impart a moment to the cup creating sliding as well as compression at the cup liner interface. The purpose of the current study is to quantify, by a validated finite element model, the forces generated in a hip arthroplasty as a result of subluxation relocation and compare them to the forces generated during normal gait. The micromotion between the liner and acetabular shell was quantified by computing the sliding track and the deformation at several points of the interface. A finite element analysis of polyethylene liner stress and liner/cup micromotion in total hip arthroplasty was performed under two dynamic profiles. The first profile was a gait loading profile simulating the force vectors developed in the hip arthroplasty during normal gait. The second profile is generated during subluxation and subsequent relocation of the femoral head. The forces generated by subluxation relocation of a total hip arthroplasty can exceed those forces generated during normal gait. The induced micromotion at the cup polyethylene interface as a result of subluxation can exceed micromotion as a result of the normal gait cycle. This may play a significant role in the generation of backsided wear. Minimizing joint subluxation by restoring balance to the hip joint after arthroplasty should be explored as a strategy to minimize backsided wear.

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Behaviour of cold-formed steel built-up I-section columns composed of four U-profiles

Advances in Structural Engineering ◽

10.1177/1369433218795568 ◽

2018 ◽

Vol 22 (3) ◽

pp. 613-625 ◽

Cited By ~ 5

Author(s):

M Anbarasu ◽

M Venkatesan

Keyword(s):

Finite Element ◽

Finite Element Model ◽

Ultimate Strength ◽

Element Model ◽

Cross Sectional ◽

Direct Strength Method ◽

The North ◽

Compression Members ◽

Cross Sectional Dimension ◽

Cold Formed Steel

This work reports numerical results concerning the cold-formed steel built-up I-section columns composed of four U-profiles under axial compression. A finite element model is developed by using the software program ABAQUS. The developed model includes geometric, material nonlinearities and geometric imperfections. The finite element model was verified against the experimental results reported in the cold-formed steel built-up open section columns. In the parametric study, the sections are analysed with several cross-sectional dimension ratios and lengths, in order to assess their influence on the buckling behaviour and ultimate strength of cold-formed steel built-up I-section columns. After presenting and discussing the numerical parametric results, the article shows that the current direct strength method in the North American Specification for cold-formed steel compression members design curve fails to predict adequately the ultimate strength of some of the columns analysed and addresses the modification proposed on current direct strength method curves, providing improved predictions of all the numerical ultimate strength available. The proposed method is also assessed by reliability analysis.

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Anatomic grooved stem mitigates strain shielding compared to established total hip arthroplasty stem designs in finite-element models

Scientific Reports ◽

10.1038/s41598-018-36503-z ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 5

Author(s):

Mark Heyland ◽

Sara Checa ◽

Daniel Kendoff ◽

Georg N. Duda

Keyword(s):

Finite Element ◽

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Finite Element Models ◽

Total Hip ◽

Strain Shielding

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Static structural analysis of different stem designs used in total hip arthroplasty using finite element method

Heliyon ◽

10.1016/j.heliyon.2019.e01767 ◽

2019 ◽

Vol 5 (6) ◽

pp. e01767 ◽

Cited By ~ 2

Author(s):

Chethan K.N. ◽

Mohammad Zuber ◽

Shyamasunder Bhat N. ◽

Satish Shenoy B. ◽

Chandrakant R. Kini

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Structural Analysis ◽

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Total Hip ◽

Element Method

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Simulation of the Residual Stresses Generated Due to Cement Polymerization in a THA

Advances in Bioengineering ◽

10.1115/imece2004-59882 ◽

2004 ◽

Author(s):

Pablo Vasquez ◽

Natalia Nun˜o

Keyword(s):

Mechanical Properties ◽

Finite Element ◽

Total Hip Arthroplasty ◽

Residual Stresses ◽

Hip Arthroplasty ◽

Proximal Femur ◽

3D Model ◽

Load Transfer ◽

Element Model ◽

Heel Strike

A personalized 3D model of the proximal femur is reconstructed from medical CT-scan images. The mechanical properties of the cortical and spongious bones are extracted from the medical images. A finite element model of a personalized total hip arthroplasty is developed to investigate the effect of residual stresses due to cement curing in the load transfer during simplified heel strike.

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