scholarly journals Computational implementation of nonuniform orthotropic directions in the femoral diaphysis based on cortical bone microstructure to build a constitutive model

2021 ◽  
Vol 9 (1) ◽  
pp. 33-58
Author(s):  
Rachele Allena ◽  
Christophe Cluzel
Keyword(s):  
Constitutive Model ◽  
Cortical Bone ◽  
Bone Microstructure ◽  
Femoral Diaphysis ◽  
Computational Implementation

scholarly journals Inhibition of Bone Loss byCissus quadrangularisin Mice: A Preliminary Report

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Jameela Banu ◽  
Erika Varela ◽  
Ali N. Bahadur ◽  
Raheela Soomro ◽  
Nishu Kazi ◽  
...  
Keyword(s):  
Side Effects ◽  
Bone Loss ◽  
Cortical Bone ◽  
Proximal Tibia ◽  
Femoral Diaphysis ◽  
Minor Trauma ◽  
Alternative Medicines ◽  
Femoral Metaphysis ◽  
Cissus Quadrangularis ◽  
Distal Femoral Metaphysis

Women drastically loose bone during and after menopause leading to osteoporosis, a disease characterized by low bone mass increasing the risk of fractures with minor trauma. Existing therapies mainly reduce bone resorption, however, all existing drugs have severe side effects. Recently, the focus is to identify alternative medicines that can prevent and treat osteoporosis with minimal or no side effects. We usedCissus quadrangularis(CQ), a medicinal herb, to determine its effects on bone loss after ovariectomy in C57BL/6 mice. Two-month old mice were either sham operated or ovariectomized and fed CQ diet. After eleven weeks, mice were sacrificed and the long bones scanned using pQCT andμCT. In the distal femoral metaphysis, femoral diaphysis, and proximal tibia, control mice had decreased cancellous and cortical bone, while CQ-fed mice showed no significant differences in the trabecular number, thickness, and connectivity density, between Sham and OVX mice, except for cortical bone mineral content in the proximal tibia. There were no changes in the bone at the tibio-fibular junction between groups. We conclude that CQ effectively inhibited bone loss in the cancellous and cortical bones of femur and proximal tibia in these mice.

scholarly journals High-throughput phenotyping and genetic linkage of cortical bone microstructure in the mouse

BMC Genomics ◽  
2015 ◽  
Vol 16 (1) ◽  
Author(s):  
Kevin S Mader ◽  
Leah Rae Donahue ◽  
Ralph Müller ◽  
Marco Stampanoni
Keyword(s):  
Cortical Bone ◽  
High Throughput ◽  
Genetic Linkage ◽  
Bone Microstructure ◽  
High Throughput Phenotyping

Strong and significant genetic effects on osteonal remodeling-associated cortical bone microstructure in pedigreed baboons

Bone ◽  
2008 ◽  
Vol 42 ◽  
pp. S53-S54 ◽  
Author(s):  
Lorena M. Havill ◽  
Jennifer A.K. Harris ◽  
Shayna M. Levine ◽  
Michael C. Mahaney
Keyword(s):  
Cortical Bone ◽  
Bone Microstructure ◽  
Genetic Effects

scholarly journals Homogenization of cortical bone reveals that the organization and shape of pores marginally affect elasticity

2019 ◽  
Vol 16 (151) ◽  
pp. 20180911 ◽  
Author(s):  
Xiran Cai ◽  
Renald Brenner ◽  
Laura Peralta ◽  
Cécile Olivier ◽  
Pierre-Jean Gouttenoire ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Volume Fraction ◽  
Transversely Isotropic ◽  
Pore Network ◽  
Anisotropic Elasticity ◽  
Homogenization Method ◽  
Femoral Diaphysis ◽  
Micro Computed Tomography ◽  
Architectural Features ◽  
Resonant Ultrasound

With ageing and various diseases, the vascular pore volume fraction (porosity) in cortical bone increases, and the morphology of the pore network is altered. Cortical bone elasticity is known to decrease with increasing porosity, but the effect of the microstructure is largely unknown, while it has been thoroughly studied for trabecular bone. Also, popular micromechanical models have disregarded several micro-architectural features, idealizing pores as cylinders aligned with the axis of the diaphysis. The aim of this paper is to quantify the relative effects on cortical bone anisotropic elasticity of porosity and other descriptors of the pore network micro-architecture associated with pore number, size and shape. The five stiffness constants of bone assumed to be a transversely isotropic material were measured with resonant ultrasound spectroscopy in 55 specimens from the femoral diaphysis of 29 donors. The pore network, imaged with synchrotron radiation X-ray micro-computed tomography, was used to derive the pore descriptors and to build a homogenization model using the fast Fourier transform (FFT) method. The model was calibrated using experimental elasticity. A detailed analysis of the computed effective elasticity revealed in particular that porosity explains most of the variations of the five stiffness constants and that the effects of other micro-architectural features are small compared to usual experimental errors. We also have evidence that modelling the pore network as an ensemble of cylinders yields biased elasticity values compared to predictions based on the real micro-architecture. The FFT homogenization method is shown to be particularly efficient to model cortical bone.

scholarly journals BMD-Related Genetic Risk Scores Predict Site-Specific Fractures as Well as Trabecular and Cortical Bone Microstructure

2020 ◽  
Vol 105 (4) ◽  
pp. e1344-e1357 ◽  
Author(s):  
Maria Nethander ◽  
Ulrika Pettersson-Kymmer ◽  
Liesbeth Vandenput ◽  
Mattias Lorentzon ◽  
Magnus Karlsson ◽  
...  
Keyword(s):  
Trabecular Bone ◽  
Cortical Bone ◽  
Hip Fractures ◽  
Vertebral Fractures ◽  
Genetic Risk ◽  
Bone Microstructure ◽  
Risk Scores ◽  
Site Specific ◽  
Microstructure Parameters ◽  
Trabecular Bone Microstructure

Abstract Context It is important to identify patients at highest risk of fractures. Objective To compare the separate and combined performances of bone-related genetic risk scores (GRSs) for prediction of forearm, hip and vertebral fractures separately, as well as of trabecular and cortical bone microstructure parameters separately. Design, Setting, and Participants Using 1103 single nucleotide polymorphisms (SNPs) independently associated with estimated bone mineral density of the heel (eBMD), we developed a weighted GRS for eBMD and determined its contribution to fracture prediction beyond 2 previously developed GRSs for femur neck BMD (49 SNPs) and lumbar spine BMD (48 SNPs). Associations between these GRSs and forearm (ncases = 1020; ncontrols = 2838), hip (ncases = 1123; ncontrols = 2630) and vertebral (ncases = 288; ncontrols = 1187) fractures were evaluated in 3 Swedish cohorts. Associations between the GRSs and trabecular and cortical bone microstructure parameters (n = 426) were evaluated in the MrOS Sweden cohort. Results We found that eBMDGRS was the only significant independent predictor of forearm and vertebral fractures while both FN-BMDGRS and eBMDGRS were significant independent predictors of hip fractures. The eBMDGRS was the major GRS contributing to prediction of trabecular bone microstructure parameters while both FN-BMDGRS and eBMDGRS contributed information for prediction of cortical bone microstructure parameters. Conclusions The eBMDGRS independently predicts forearm and vertebral fractures while both FN-BMDGRS and eBMDGRS contribute independent information for prediction of hip fractures. We propose that eBMDGRS captures unique information about trabecular bone microstructure useful for prediction of forearm and vertebral fractures. These findings may facilitate personalized medicine to predict site-specific fractures as well as cortical and trabecular bone microstructure separately.

scholarly journals Effect of Using Coolant on the Formation of Microcracks, Burr and Delamination in Bone Drilling Process

2021 ◽  
Vol 1 (1) ◽  
pp. 17-26
Author(s):  
Rusnaldy Rusnaldy ◽  
Pratama Eka Putra Sijabat ◽  
Paryanto Paryanto ◽  
Toni Prahasto
Keyword(s):  
Cortical Bone ◽  
Bone Microstructure ◽  
Initial Position ◽  
Burr Formation ◽  
Drilling Process ◽  
Bone Drilling ◽  
Screw Insertion ◽  
Bone Surgery ◽  
Drilling Temperature ◽  
The Stability

Direct approach for bone fracture treatment usually involves restoring the fractured parts to their initial position and immobilizing them with plates, screws and wires. This approach needs a bone surgery drilling to produce hole for screw insertion. But this drilling process causes mechanical damages, i.e microcracks, burr formation and delamination, that can reduce the stability of the fixation. One of the ways to minimize it is by using coolant. Moreover, it is noted that bone has anisotropic microstucture. The object of this study is to understand the effect of coolant on mechanical damages that occur in bone drilling and to understand the effect of microstructure difference on microcracks that occur in the drilled walls holes. Adult bovine bones and adult goat bones were used in this study as the specimens to represent differences in cortical bone microstructure. Five consecutive holes from the distal to the proximal in each specimen were generated using manual hand-drill (spindle speed (n) = 1000 rpm; drill bit (d) = 4 mm diameter) with the use of coolant as variation. The drilling holes then stained and observed using a microscope. As the result, it was found that the use of coolant can significantly reduce the drilling temperature. Microcracks, burr formation and delamination were found to be quite large in the drilling holes without coolant. However, there is no microcrack found in the drilling holes with coolant, there is only a small number of burr formation was found. In addition, it was found that the differences in bone microstructure affect the number and length of microcracks that occur in the wall of the hole. It can be concluded from this study that the application of coolant is very effective to reduce the drilling temperature and enhancing the quality of the hole generated by bone drilling and the higher the density of osteon in cortical bone, the easier the microcrack to initiate and propagate.

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