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To what extent can linear finite element Models of Human femora predict failure under stance and fall loading configurations?

Schileo, Enrico; Balistreri, Luca; Grassi, Lorenzo LU ; Cristofolini, Luca and Taddei, Fulvia (2014) In Journal of Biomechanics
Abstract
Proximal femur strength estimates from Computed Tomography (CT)-based Finite Element (FE) models are finding clinical application. Published models reached a high in-vitro accuracy, yet many of them rely on nonlinear methodologies or internal best-fitting of parameters. The aim of the present study is to verify to what extent a linear FE modelling procedure, fully based on independently determined parameters, can predict the failure characteristics of the proximal femur in stance and sideways fall loading configurations.



Fourteen fresh-frozen cadaver femora were CT-scanned. Seven femora were tested to failure in stance loading conditions, and seven in fall. Fracture was monitored with high-speed videos. Linear FE models... (More)
Proximal femur strength estimates from Computed Tomography (CT)-based Finite Element (FE) models are finding clinical application. Published models reached a high in-vitro accuracy, yet many of them rely on nonlinear methodologies or internal best-fitting of parameters. The aim of the present study is to verify to what extent a linear FE modelling procedure, fully based on independently determined parameters, can predict the failure characteristics of the proximal femur in stance and sideways fall loading configurations.



Fourteen fresh-frozen cadaver femora were CT-scanned. Seven femora were tested to failure in stance loading conditions, and seven in fall. Fracture was monitored with high-speed videos. Linear FE models were built from CT images according to a procedure already validated in the prediction of strains. An asymmetric maximum principal strain criterion (0.73% tensile, 1.04% compressive limit) was used to define a node-based Risk Factor (RF). FE-predicted failure load, mode (tensile/compressive) and location were determined from the first node reaching RF=1.



FE-predicted and measured failure loads were highly correlated (R2=0.89, SEE=814 N). In all specimens, FE models correctly identified the failure mode (tensile in stance, compressive in fall) and the femoral region where fracture started (supero-lateral neck aspect). The location of failure onset was accurately predicted in eight specimens.



In summary, a simple FE model, adaptable in the future to multiple loads (e.g. including muscles), was highly correlated with experimental failure in two loading conditions on specimens ranging from normal to osteoporotic. Thus, it can be suitable for use in clinical studies. (Less)
Please use this url to cite or link to this publication:
author
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Subject-specific Finite Element Models, Proximal Femur, Bone Biomechanics, Validation, Computed Tomography
in
Journal of Biomechanics
publisher
Elsevier
external identifiers
  • scopus:84922599020
ISSN
1873-2380
DOI
10.1016/j.jbiomech.2014.08.024
language
English
LU publication?
no
id
b09632e7-d26b-4c76-8910-1aee9323e52b (old id 4631481)
alternative location
http://www.sciencedirect.com/science/article/pii/S0021929014004606
date added to LUP
2014-09-15 10:15:45
date last changed
2017-11-05 04:42:13
@article{b09632e7-d26b-4c76-8910-1aee9323e52b,
  abstract     = {Proximal femur strength estimates from Computed Tomography (CT)-based Finite Element (FE) models are finding clinical application. Published models reached a high in-vitro accuracy, yet many of them rely on nonlinear methodologies or internal best-fitting of parameters. The aim of the present study is to verify to what extent a linear FE modelling procedure, fully based on independently determined parameters, can predict the failure characteristics of the proximal femur in stance and sideways fall loading configurations.<br/><br>
<br/><br>
Fourteen fresh-frozen cadaver femora were CT-scanned. Seven femora were tested to failure in stance loading conditions, and seven in fall. Fracture was monitored with high-speed videos. Linear FE models were built from CT images according to a procedure already validated in the prediction of strains. An asymmetric maximum principal strain criterion (0.73% tensile, 1.04% compressive limit) was used to define a node-based Risk Factor (RF). FE-predicted failure load, mode (tensile/compressive) and location were determined from the first node reaching RF=1.<br/><br>
<br/><br>
FE-predicted and measured failure loads were highly correlated (R2=0.89, SEE=814 N). In all specimens, FE models correctly identified the failure mode (tensile in stance, compressive in fall) and the femoral region where fracture started (supero-lateral neck aspect). The location of failure onset was accurately predicted in eight specimens.<br/><br>
<br/><br>
In summary, a simple FE model, adaptable in the future to multiple loads (e.g. including muscles), was highly correlated with experimental failure in two loading conditions on specimens ranging from normal to osteoporotic. Thus, it can be suitable for use in clinical studies.},
  author       = {Schileo, Enrico and Balistreri, Luca and Grassi, Lorenzo and Cristofolini, Luca and Taddei, Fulvia},
  issn         = {1873-2380},
  keyword      = {Subject-specific Finite Element Models,Proximal Femur,Bone Biomechanics,Validation,Computed Tomography},
  language     = {eng},
  publisher    = {Elsevier},
  series       = {Journal of Biomechanics},
  title        = {To what extent can linear finite element Models of Human femora predict failure under stance and fall loading configurations?},
  url          = {http://dx.doi.org/10.1016/j.jbiomech.2014.08.024},
  year         = {2014},
}