Experimental Validation of Finite Element Models of Intact and Implanted Composite Hemipelvises Using Digital Image Correlation

Pal

Computer Methods in Biomechanics and Biomedical Engineering

et al. 2013

Self Cite

An appropriate method of application of the hip-joint force and stress analysis of the pelvic bone, in particular the acetabulum, is necessary to investigate the changes in load transfer due to implantation and to calculate the reference stimulus for bone remodelling simulations. The purpose of the study is to develop a realistic 3D finite element (FE) model of the hemi-pelvis and to assess stress and strain distribution during a gait cycle. The FE modelling approach of the pelvic bone was based on CT scan data and image segmentation of cortical and cancellous bone boundaries. Application of hip-joint force through an anatomical femoral head having a cartilage layer was found to be more appropriate than a perfectly spherical head, thereby leading to more accurate stress-strain distribution in the acetabulum. Within the acetabulum, equivalent strains varied between 0.1% and 0.7% strain in the cancellous bone. High compressive (15-30 MPa) and low tensile (0-5 MPa) stresses were generated within the acetabulum. The hip-joint force is predominantly transferred from the acetabulum through the lateral cortex to the sacroiliac joint and the pubic symphysis. The study is useful to understand the load transfer within the acetabulum and for further investigations on acetabular prosthesis.

Section: Verification and Qualitative Validation O F The Fe Modelmentioning

confidence: 99%

“…Comparison of tensile (positive) and compressive (negative) numerical strains in the intact pelvis with experimental data ofGhosh et al (2012Ghosh et al ( , 2013 at six different locations. Numbers 1-6 on the abscissa indicate locations of measured points.…”

mentioning

confidence: 99%

Finite element analysis of a hemi-pelvis: the effect of inclusion of cartilage layer on acetabular stresses and strain

Pal

Computer Methods in Biomechanics and Biomedical Engineering

et al. 2013

Self Cite

“…The AC implant stability has also been assessed in simulation studies through the measurement of relative micromotion occurring at the bone-implant interface during simulated gait cycles or others daily activities [6,16,17] or using other biomechanical tests such as push-in [18], pull-out and edge loading tests [19]. Experimental methods have been developed to assess the femoral stem stability [20, Finite element model of the impaction of a press-fitted acetabular cup: estimation of the contact area.…”

Section: Introductionmentioning

confidence: 99%

Finite element model of the impaction of a press-fitted acetabular cup

Michel

Nguyen

Bosc

et al. 2016

Med Biol Eng Comput

Finite element model of the impaction of a press-fitted acetabular cup: estimation of the contact area. Finite element model of the impaction of a press-fitted acetabular cup: estimation of the contact area. 2 AbstractPress-fit surgical procedures aim at providing primary stability to acetabular cup (AC) implants. Impact analysis constitutes a powerful approach to retrieve the AC implant insertion properties. The aim of this numerical study was to investigate the dynamic interaction occurring between the hammer, the ancillary and bone tissue during the impact and to assess the potential of impact analysis to retrieve AC implant insertion conditions. A dynamic two-dimensional axisymmetric model was developed to simulate the impaction of the AC implant into bone tissue assuming friction at the bone-implant interface and large deformations. Different values of interference fit (from 0.5 to 2 mm) and impact velocities (from 1 to 2 m.s -1 ) were considered. For each configuration, the variation of the force applied between the hammer and the ancillary was analyzed and an indicator I was determined based on the impact momentum of the signal.The simulated results are compared to the experiments. The value of the polar gap decreases versus the impact velocity and increases versus the interference fit. The bone implant contact area was significantly correlated with the resonance frequency (R 2 =0.94) and the indicator (R 2 =0.95).The results show the potential of impact analyses to retrieve the bone-implant contact properties.Keywords: Acetabular cup; hip replacement; impact; finite element; bone; Biomechanics; bone Author Biographies:Adrien Michel has completed his PhD in biomechanics in the MSME laboratory. Romain Bosc and Philippe Hernigou are experienced surgeons. Vu-Hieu Nguyen and Salah Naili are experts in mechanical modeling and simulation. Romain Vayron and Guillaume Haiat are specialized in biomechanical engineering of implants.Finite element model of the impaction of a press-fitted acetabular cup: estimation of the contact area.3

Biomech Model Mechanobiol

“…The implanted hemi-pelvis was meshed with ten-node tetrahedral elements with maximum edge length of 3 mm using ANSYS v14.0 software (ANSYS Inc., Canons- burg, PA, USA). The validity of implanted hemi-pelvis FE model and FE model generation procedure were extensively tested (Ghosh et al 2012(Ghosh et al , 2013a. The Young's modulus and Poisson's ratio of the implant were assumed to be 210 GPa and 0.3, respectively (Yew et al 2006;Hothi 2012;Ghosh et al 2013b).…”

Section: Development Of Fe Model Of An Implanted Pelvismentioning

confidence: 99%

Bone ingrowth around porous-coated acetabular implant: a three-dimensional finite element study using mechanoregulatory algorithm

Mukherjee

Gupta

2015

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Fixation of uncemented implant is influenced by peri-prosthetic bone ingrowth, which is dependent on the mechanical environment of the implant-bone structure. The objective of the study is to gain an insight into the tissue differentiation around an acetabular component. A mapping framework has been developed to simulate appropriate mechanical environment in the three-dimensional microscale model, implement the mechanoregulatory tissue differentiation algorithm and subsequently assess spatial distribution of bone ingrowth around an acetabular component, quantitatively. The FE model of implanted pelvis subjected to eight static load cases during a normal walking cycle was first solved. Thereafter, a mapping algorithm has been employed to include the variations in implant-bone relative displacement and host bone material properties from the macroscale FE model of implanted pelvis to the microscale FE model of the beaded implant-bone interface. The evolutionary tissue differentiation was observed in each of the 13 microscale models corresponding to 13 acetabular regions. The total implant-bone relative displacements, averaged over each region of the acetabulum, were found to vary between 10 and 60 μm. Both the linear elastic and biphasic poroelastic models predicted similar mechanoregulatory peri-prosthetic tissue differentiation. Considerable variations in bone ingrowth (13-88%), interdigitation depth (0.2-0.82 mm) and average tissue Young's modulus (970-3430 MPa) were predicted around the acetabular cup. A progressive increase in the average Young's modulus, interdigitation depth and decrease in average radial strains of newly formed tissue layer were also observed. This scheme can be extended to investigate tissue differentiation for different surface texture designs on the implants.