Automation of the Peak Fitting Method in Bone FTIR Microspectroscopy Spectrum Analysis: Human and Mice Bone Study

FTIR microspectroscopy (FTIRM) is a commonly used nondestructive method to characterise thin bone sections. However, spectrum analysis methods are often highly sensitive to small variations (e.g., boundary limits), thus implying a time-consuming and redundant analysis process. To solve this issue, software has been developed based on several algorithms to automate the analysis. Furthermore, a rigorous framework has been established concerning the peak fitting method to obtain the systematic best potential solution. Validation of the automatic method has been performed by comparison with the manual method. Results and validation proved the reliability of the automatic process. The developed algorithms provide the means necessary to fully compare the results between bone FTIRM studies and between different laboratories

A credible homogenized finite element model to predict radius fracture in the case of a forward fall

Fragility fractures that occur after a fall from a standing height or less are almost always due to osteoporosis, which remains underdiagnosed and untreated. Patient-specific finite element (FE) models have been introduced to predict bone strength and strain. This approach, based on structure mechanics, is derived from Quantitative Computed Tomography (QCT), and element mechanical properties are computed from bone mineral densities. In this study, we developed a credible finite element model of the radius to discriminate low-trauma-fractured radii from non-fractured radii obtained experimentally. Thirty cadaveric radii were impacted with the same loading condition at 2 m/s, and experimental surface strain was retrieved by stereo-correlation in addition to failure loads in fracture cases. Finite element models of the distal radius were created from clinical computed tomography. Different density-elasticity relationships and failure criteria were tested. The strongest agreement (simulations-experiments) for average strain showed a Spearman's rank correlation (?) between 0.75 and 0.82, p < 0.0001, with a root mean square error between 0.14 and 0.19%. The experimental mean strain was 0.55%. Predicted failure load error (23%) was minimized for derived Pistoia's failure criterion. Numerical failure demonstrated area under the receiver operating characteristic (ROC) curves of 0.76 when classifying radius fractures with an accuracy of 82%. These results suggest that a credible FE modelling method in a large region of interest (distal radius) is a suitable technique to predict radius fractures after a forward fall

Design of a physiological spinal posture predictor in the piper project

International audienceCurrent approaches towards subject-specific FE modelling and virtual testing would benefit from easy-to-use personalization and positioning tools. The PIPER project aims to provide these tools for full human body FE models used in automotive safety as an open-source, easy-to-use software framework that is independent from both model and FE code. In this context the positioning of the spine is of particular interest, while remaining complex because of its high number of dofs. This abstract presents the development of a spline based spinal posture predictor tool relying on linear interpolation between known physiological postures, and its implementation within the PIPER tool

Design of a physiological spinal posture predictor in the piper project

International audienceCurrent approaches towards subject-specific FE modelling and virtual testing would benefit from easy-to-use personalization and positioning tools. The PIPER project aims to provide these tools for full human body FE models used in automotive safety as an open-source, easy-to-use software framework that is independent from both model and FE code. In this context the positioning of the spine is of particular interest, while remaining complex because of its high number of dofs. This abstract presents the development of a spline based spinal posture predictor tool relying on linear interpolation between known physiological postures, and its implementation within the PIPER tool

Design of a physiological spinal posture predictor in the piper project

Current approaches towards subject-specific FE modelling and virtual testing would benefit from easy-to-use personalization and positioning tools. The PIPER project aims to provide these tools for full human body FE models used in automotive safety as an open-source, easy-to-use software framework that is independent from both model and FE code. In this context the positioning of the spine is of particular interest, while remaining complex because of its high number of dofs. This abstract presents the development of a spline based spinal posture predictor tool relying on linear interpolation between known physiological postures, and its implementation within the PIPER tool

Les modèles biomécaniques intègrent l'anatomie du squelette pour estimer la résistance osseuse : validation et reproductibilité, In: L'os

Ce livre, témoin de l'approche scientifique de la société, est comme habituellement multidisciplinaire, à la fois clinique et radiologique avec l'intervention des meilleurs orateurs spécialistes du sujet. Six thématiques particulièrement originales sont abordées : l'Os et ses fondamentaux, l'Os sollicité ou traumatisé, l'Os métabolique, l'Os inflammatoire et infectieux, l'Os tumoral et enfin l'Os différent. Les nombreux auteurs ont pu développer et élargir chaque sujet, agrémenté d'une iconographie toujours plus abondante et de grande qualité.Un tel ouvrage édité par notre fidèle partenaire Sauramps Médical et disponible le jour même du congrès, ne peut être réalisé chaque année sans un grand nombre d'acteurs, auteurs, relecteurs, correcteurs, éditeur, imprimeur qui n'ont pas ménagé leurs efforts pour enrichir dans les temps cette collection unique, le tout orchestré par Frédérique Miot et Aurélie Vuibert

Variabilities in µQCT-based FEA of a tumoral bone mice model

A finite element analysis based on Micro-Quantitative Computed Tomography (µQCT) is a method with high potential to improve fracture risk prediction. However, the segmentation process and model generation are generally not automatized in their entirety. Even with a rigorous protocol, the operator might add uncertainties during the creation of the model. The aim of this study was to evaluate a µQCT-based model of mice tumoral and sham tibias in terms of the variabilities induced by the operator and sensitivity to operator-dependent variables (such as model orientation or length). Two different operators generated finite element (FE) models from µCT images of 8 female Balb/c nude mice tibias aged 10 weeks old with bone tumors induced in the right tibia and with sham injection in the left. From these models, predicted failure load was determined for two different boundary conditions: fixed support and spherical joints. The difference between the predicted and experimental failure load of both operators was large (-122% to 93%). The difference in the predicted failure load between operators was less for the spherical joints boundary conditions (9.8%) than for the fixed support (58.3%),

Inter-operator variability of a finite element model of femurs with and without simulated metastatic defects

ESB2021, 26th Congress of the European Society of Biomechanics, Milan, ITALIE, 11-/07/2021 - 14/07/2021Femur metastases are associated with severe skeletal complications, including bone fracture [1]. Clinical scores, such as Mirel's, poorly estimate the risk of fracture. A recent study showed that subject-specific finite element (FE) models, based on QCT imaging, outweigh the performance of clinical experts when applied to patients [2]. However, several parameters of the FE models are operator-dependent and may affect the calculated failure load. The uncertainty on these parameters and their effects on the failure load have not been quantified. Therefore, the aim of the current study is to assess the inter-operator variability in a finite element model of femurs with and without created defects representing osteolytic metastases

Influence of the degree of mineralization of the cortical bone on toughness

42e Congrès de la Société de Biomécanique, Reims, France, 02-/11/2017 - 02/11/2017Bone quality and fracture prediction are dependent topics that have long been blurry, quite unreachable links to establish. The International Osteoporosis Foundation expects an increase of nearly three times more hip fractures in the population by 2050. Regarding this expectation, the MULTIPS project aims to predict the bone fracture risk by quantifying the bone quality using different methods. One of them is the Degree of Mineralization of the Bone (DMB (g.cm?3)) analysis by X-ray scanning of a 100 ± 1 ?m thick section of embedded bone. The aim of the present study is to assess the effect of bone mineralization (DMB) on the toughness of the bone which is the propensity to resist to fracture

Failure load prediction of metastatic femur mechanical characterization and finite element modelling

BONITOS, BONe InTerdisciplinary sympOSium, Villeurbanne, FRANCE, 17-/09/2021 - 17/09/2021-