Prediction of the mechanical response of canine humerus to three-point bending using subject-specific finite element modelling

Abstract

Subject-specific finite element (FE) models could improve decision making in canine long bone fracture repair. However, it preliminary requires that FE models predicting the mechanical response of canine long bone are proposed and validated. We present here a combined experimental-numerical approach to test the ability of subjectspecific FE models to predict the bending response of seven pairs of canine humeri directly from medical images. Our results show that bending stiffness and yield load are predicted with a mean absolute error of 10.1% (±5.2%) for the fourteen samples.This study constitutes a basis for the forthcoming optimization of canine long bone fracture repair.

How do the effective bone properties evolve during normal and pathological calcification?

“…Bone geometries were reconstructed using previously reported methods (Laurent et al 2016) to build a subject-specific FE model of each femur, with density-elasticity relationships that constituted the unknown to be identified together with the yield stress, considered as a function of the elastic modulus of each element. The elastic properties of skeletal tissue were assessed from inverse method based on the experimental bending stiffness and the information available in calibrated CT, considering that the FE models provide with reliable bending response prediction as reported in (Laurent et al 2016). The effect of calcification was taken into account in the computations by introducing an isotropic damage variable (Mengoni and Ponthot 2010), taking the fully calcified bone as the undamaged reference.…”

“…In addition to such observations, mechanical testing may give an access to the macroscopic mechanical response of small skeletal samples and permit comparative studies, but does not provide with a characterization of local tissue properties. Alternatively, various studies (Laurent et al 2016) have emphasized that Computed Tomography (CT) may be used to predict overall bone stiffness using subject-specific Finite Element (FE) models. FE models may then be used to identify bone properties using an inverse method, based on experimental biomechanical data, in order to identify bone properties.…”

Effect of orthopedic implants on canine long bone compression stiffness: a combined experimental and computational approach

“…Each tested sample was modeled with a subjectspecific approach, as described previously. 7 The geometry of the bone was segmented from the threedimensional (3D) computer tomography (CT) data using 3D Slicer (https://www.slicer.org/), and a dedicated in-house algorithm was used for the generation of smooth multi-region surface meshes. 32 The bone volume mesh made of linear tetrahedrons was obtained using TetGen (WIAS, Berlin, Germany).…”

“…Moreover, canine osteosynthesis surgery is associated with some challenges that do not exist in human medicine, such as dog size variability, limited capacity of post-surgery immobilization and cost limitations. Several studies have been conducted to create FE models of bone focusing on different aspects of the modeling approach in human, [2][3][4][5][6][7][8][9][10][11][12][13][14] but such studies are missing for dogs. Long bones under compression studies were conducted both for humans 4,15 and some animals as mice, 16 dogs 17 or cows.…”

“…Bending stiffness and yield load were predicted with an error inferior to 10% compared to experimental results. 7 Once a subject-specific FE model of a bone under given loading conditions has been validated, boneimplant (plates, screws, nails) constructs can be modeled in order to develop a patient-specific assisting tool for surgeons. Several studies have been conducted to assess the mechanical properties and/or clinical outcome of such bone-implant constructs and interactions [18][19][20][21] or to compare different plates or nails.…”