title: Factors affecting subject-specific finite element models of implant-fitted rat bone specimens: critical analysis of a technical protocol.
abstract: The authors propose a protocol to derive finite element (FE) models from micro computer tomography scans of implanted rat bone. A semi-automatic procedure allows segmenting the images using specimen-specific bone mineral density (BMD) thresholds. An open-source FE model generator processes the segmented images to a quality tetrahedral mesh. The material properties assigned to each element are integrated from the BMD field. Piecewise, threshold-dependent density-elasticity relationships are implemented to limit the effects of metal artefacts. A detailed sensitivity study highlights the coherence of the generated models and quantifies the influence of the modelling parameters on the results. Two applications of the protocol are proposed. The stiffness of bare and implanted rat tibiae specimens is predicted by simulating three-point bending and inter-implant displacement, respectively. Results are compared with experimental tests. The mean value and the variability between the specimens are well captured in both tests.
authors.affiliation: a Laboratory of Applied Mechanics and Reliability Analysis, École Polytechnique Fédérale de Lausanne , Station 9, CH-1015 Lausanne , Switzerland.
authors.forename: Marco
authors.initials: M
authors.lastname: Piccinini
authors.forename: Joel
authors.initials: J
authors.lastname: Cugnoni
authors.forename: John
authors.initials: J
authors.lastname: Botsis
authors.forename: Giovanna
authors.initials: G
authors.lastname: Zacchetti
authors.forename: Patrick
authors.initials: P
authors.lastname: Ammann
authors.forename: Anselm
authors.initials: A
authors.lastname: Wiskott
mesh_terms: D000818:Animals; D015519:Bone Density; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000502:physiology*; D003198:Computer Simulation; D004548:Elasticity; D020342:Finite Element Analysis; D008954:Models, Biological; D019736:Prostheses and Implants; D051381:Rats; D017207:Rats, Sprague-Dawley; D014057:Tomography, X-Ray Computed
keywords: bone; finite element; implant-fitted; segmentation; subject-specific; tomography