Alidation of Cross-Sectional Method for Metastatic Femur Failure Prediction Using Finite Element Analysis

Metastatic bone lesions are a major form of cancer proliferation often originating from breast cancer. Surgical measures to prevent bone failure involve high risks for the patients involved. For this reason, a femur failure prediction method is being devised at the Orthopedic Biomechanics Laboratory, which assesses the risk of bone fracture according to tomographic analysis data.

The goal of this project was to validate this method by finite element analysis and mechanical loading of rat femurs.

The data, with which the finite element model was created was obtained from a mi- crocomputed tomograph (μct40®). An STL surface representation was generated using IPL. The mesh was then generated using the STL file in Truegrid®.

Using Matlab®, the material properties were assigned to the elements using tomo- graphic measurements of the linear attenuation coefficient of the femur and converting these to Mineral Density and Young’s modulus [1]. The material data was then re-entered into Truegrid

A complete mesh containing locally varying material properties was successfully cre- ated with this method.

In conclusion, due to the time-consuming nature of smooth mesh generation, the val- idation of this method, as well as mechanical testing could not be undertaken. However, this report was designed as a guideline, with which to generate a mesh of femurs, therefore creating a detailed manual, which will facilitate future use of this methodology.

Year	Entry
1998	Viceconti M, Bellingeri L, Cristofolini L, Toni A. A comparative study on different methods of automatic mesh generation of human femurs. Med Eng Phys. January 1998;20(1):1-10.
2003	Keyak JH, Falkinstein Y. Comparison of in situ and in vitro CT scan-based finite element model predictions of proximal femoral fracture load. Med Eng Phys. November 2003;25(9):781-787.
2003	Wirtz DC, Pandorf T, Portheine F, Radermacher K, Schiffers N, Prescher A, Weichert D, Niethard FU. Concept and development of an orthotropic FE model of the proximal femur. J Biomech. February 2003;36(2):289-293.
2004	Taddei F, Pancanti A, Viceconti M. An improved method for the automatic mapping of computed tomography numbers onto finite element models. Med Eng Phys. 2004;26(1):61-69.
1994	Keyak JH, Lee IY, Skinner HB. Correlations between orthogonal mechanical properties and density of trabecular bone: use of different densitometric measures. J Biomed Mater Res. November 1994;A28(11):1329-1336.
2004	Kaneko TS, Bell JS, Pejcic MR, Tehranzadeh J, Keyak JH. Mechanical properties, density and quantitative CT scan data of trabecular bone with and without metastases. J Biomech. April 2004;37(4):523-530.
2001	Whyne CM, Hu SS, Lotz JC. Parametric finite element analysis of verterbral bodies affected by tumors. J Biomech. October 2001;34(10):1317-1324.
2004	Viceconti M, Davinelli M, Taddei F, Cappello A. Automatic generation of accurate subject-specific bone finite element models to be used in clinical studies. J Biomech. 2004;37(10):1597-1605.

Year

Entry

1998

Viceconti M, Bellingeri L, Cristofolini L, Toni A. A comparative study on different methods of automatic mesh generation of human femurs. Med Eng Phys. January 1998;20(1):1-10.

2003

Keyak JH, Falkinstein Y. Comparison of in situ and in vitro CT scan-based finite element model predictions of proximal femoral fracture load. Med Eng Phys. November 2003;25(9):781-787.

2003

Wirtz DC, Pandorf T, Portheine F, Radermacher K, Schiffers N, Prescher A, Weichert D, Niethard FU. Concept and development of an orthotropic FE model of the proximal femur. J Biomech. February 2003;36(2):289-293.

2004

Taddei F, Pancanti A, Viceconti M. An improved method for the automatic mapping of computed tomography numbers onto finite element models. Med Eng Phys. 2004;26(1):61-69.

1994

Keyak JH, Lee IY, Skinner HB. Correlations between orthogonal mechanical properties and density of trabecular bone: use of different densitometric measures. J Biomed Mater Res. November 1994;A28(11):1329-1336.

2004

Kaneko TS, Bell JS, Pejcic MR, Tehranzadeh J, Keyak JH. Mechanical properties, density and quantitative CT scan data of trabecular bone with and without metastases. J Biomech. April 2004;37(4):523-530.

2001

Whyne CM, Hu SS, Lotz JC. Parametric finite element analysis of verterbral bodies affected by tumors. J Biomech. October 2001;34(10):1317-1324.

2004

Viceconti M, Davinelli M, Taddei F, Cappello A. Automatic generation of accurate subject-specific bone finite element models to be used in clinical studies. J Biomech. 2004;37(10):1597-1605.