Finite Element Prediction and Experimental Verification of the Failure Pattern of Proximal Femur using Quantitative Computed Tomography Images

This paper presents a novel method for prediction of the mechanical behavior of proximal femur using the general framework of the quantitative computed tomography (QCT)-based finite element Analysis (FEA). A systematic imaging and modeling procedure was developed for reliable correspondence between the QCT-based FEA and the in-vitro mechanical testing. A speciallydesigned holding frame was used to define and maintain a unique geometrical reference system during the analysis and testing. The QCT images were directly converted into voxel-based 3D finite element models for linear and nonlinear analyses. The equivalent plastic strain and the strain energy density measures were used to identify the critical elements and predict the failure patterns. The samples were destructively tested using a specially-designed gripping fixture (with five degrees of freedom) mounted within a universal mechanical testing machine. Very good agreements were found between the experimental and the predicted failure patterns and the associated load levels.

Authors:

• Majid Mirzaei
• Saeid Samiezadeh
• Abbas Khodadadi
• Mohammad R. Ghazavi

Keywords:

• Bone
• Osteoporosis
• Noninvasive methods
• Failure Analysis

References:

[1] P. Sambrook, C. Cooper, "Osteoporosis," Lancet, vol. 367, no. 9527,
pp. 2010-2018, 2006.
[2] M.A.K. Liebschner, D.L. Kopperdahl, W.S. Rosenberg, T.M. Keaveny,
"Finite element modeling of the human thoracolumbar spine," Spine,
vol. 28, pp. 559-565, 2003.
[3] R.P. Crawford, C.E. Cann, T.M. Keaveny, "Finite element models
predict in vitro vertebral body compressive strength better than
quantitative computed tomography," Bone, vol. 33, pp. 744-750, 2003.
[4] J.M. Buckley, K. Loo, J. Motherway, "Comparison of quantitative
computed tomography-based measures in predicting vertebral
compressive strength," Bone, vol. 40, pp. 767-774, 2007.
[5] M. Mirzaei, A. Zeinali, A. Razmjoo, M. Nazemi, "On prediction of the
strength levels and failure patterns of human vertebrae using
quantitative computed tomography (QCT)-based finite element
method," J Biomech, vol. 42, pp. 1584-1591, 2009.
[6] J.H. Keyak, S.A. Rossi, K.A. Jones, H.B. Skinner, "Prediction of
femoral fracture load using automated finite element modeling," J
Biomech, vol. 31, no. 2, pp. 125-133, 1998.
[7] J.H. Keyak, H.B. Skinner, J.A. Fleming, "Effect of force direction on
femoral fracture load for two types of loading conditions," J Orthop
Res, vol. 19, no. 4, pp. 539-544, 2001.
[8] J.H. Keyak, T.S. Kaneko, J. Tehranzadeh, H.B. Skinner, "Predicting
proximal femoral strength using structural engineering models," Clin
Orthop Relat Res, vol. 437, pp. 219-228, 2005.
[9] J.H. Keyak et al., "Male-female differences in the association between
incident hip fracture and proximal femoral strength: A finite element
analysis study," Bone, vol. 48, no. 6, pp. 1239-1245, 2011.
[10] D.D. Cody, G.J. Gross, F.J. Hou, H.J. Spencer, S.A. Goldstein, D.P.
Fyhrie, "Femoral strength is better predicted by finite element models
than QCT and DXA," J Biomech, vol. 32, no. 10, pp. 1013-1020, 1999.
[11] M. Bessho, I. Ohnishi, J. Matsuyama, T. Matsumoto, K. Imai, K.
Nakamura, "Prediction of strength and strain of the proximal femur by a
CT-based finite element method," J Biomech, vol. 40, no. 8, pp. 1745-
1753, 2007.
[12] M. Bessho, I. Ohnishi, T. Matsumoto, S. Ohashi, J. Matsuyama, K.
Tobita, M. Kaneko, K. Nakamura, "Prediction of proximal femur
strength using a CT-based nonlinear finite element method: Differences
in predicted fracture load and site with changing load and boundary
conditions," Bone, vol. 45, no. 2, pp. 226-231, 2009.
[13] Z. Yosibash, N. Trabelsi, C. Milgrom, "Reliable simulations of the
human proximal femur by high-order finite elements analysis validated
by experimental observations," J Biomech, vol. 40, pp. 3688-3699,
2007.
[14] E. Schileo, F. Taddei, L. Cristofolini, M. Viceconti, "Subject-specific
finite element models implementing a maximum principal strain
criterion are able to estimate failure risk and fracture location on human
femurs tested in vitro," J Biomech, vol. 41, no. 2, pp. 356-367, 2008.
[15] N. Trabelsi, Z. Yosibash, C. Milgrom, "Validation of subject-specific
automated p-FE analysis of the proximal femur," J Biomech, vol. 42,
no. 3, pp. 234-241, 2009.
[16] N. Trabelsi, Z. Yosibash, C. Wutte, P. Augat, S. Eberle, "Patientspecific
finite element analysis of the human femur--A double-blinded
biomechanical validation," J Biomech, vol. 44, no. 9, pp. 1666-21672,
2011.
[17] D. Dragomir-Daescu et al., "Robust QCT/FEA models of proximal
femur stiffness and fracture load during a sideways fall on the hip," Ann
Biomed Eng, vol. 39, no. 2, pp. 742-2755, 2011.
[18] C.M. Les, J.H. Keyak, S.M. Stover, K.T. Taylor, A.J. Kaneps,
"Estimation of material properties in the equine metacarpus with use of
quantitative computed tomography," J Orthop Rest, vol. 12, no. 6, pp.
822-833, 1994.
[19] J.H. Keyak, Y. Falkinstein, "Comparison of in situ and in vitro CT scanbased
finite element model predictions of proximal femoral fracture
load," Med Eng Phys, vol. 25, no. 9, pp. 781-787, 2003.
[20] J.H. Keyak, "Relationships between femoral fracture loads for two load
configurations," J Biomech, vol. 33, no. 4, pp. 499-502, 2000.
[21] L. Cristofolini, G. Conti, M. Juszczyk, S. Cremonini, S.V. Sint Jan, M.
Viceconti, "Structural behaviour and strain distribution of the long
bones of the human lower limbs," J Biomech, vol. 43, pp. 826-835,
2010.
[22] J.S. Stolken, J.H. Kinney, "On the importance of geometric nonlinearity
in finite element simulations of trabecular bone failure," Bone, vol. 33,
pp. 496-504, 2003.