34th Annual Scientific Meeting proceedings

Objectives:

Understanding the mechanical loads on intact bones is crucial for comparing
immobilization methods for femoral neck fractures. This study evaluated data on the mechanical load applied to the proximal aspect of the femoral head in dog through destructive mechanical testing and the finite element method (FEM).

Methods:

Four adult dog femurs from dogs weighing approximately 15 kg were subjected to axial
compression load applied to the femoral head at a rate of 5 mm/second until failure. Maximum force and stiffness were measured. For FEM, a random femur underwent a computed tomography scan, and the data were used to create a 3D model in Simpleware software. The generated STL file was imported into Meshmixer software for manual correction and surface mesh recovery using the Sculpt tool. Ansys software was used to replicate the test conditions to perform model validation, comparing the relative error of the numerical model to the real model under the same boundary conditions. The Transient Structural tool was used to apply an increasing load to the model and obtain the variable load to the material deformation.

Results:

The maximum force (N) was 2358.44 ± 214.48 N and stiffness was 613.11 ± 33.59
mm. For the analytical calculation of the relative errors, a stiffness of 733.35 was obtained for the test and 800.49 for the simulation, resulting in a relative error of 8.39%.

Conclusions:

According to engineering standards, this is an acceptable error for the numerical
model, and therefore, the model was properly validated.