Modal Frequencies of Long Tibia Bones: Heterogeneous vs Homogeneous Material Considerations

2017 ◽  
Author(s):  
Reem A. Yassine ◽  
Mohammad Karim Elham ◽  
Samir Mustapha ◽  
Ramsey F. Hamade
Keyword(s):  
Heterogeneous Material ◽  
Approximate Solutions ◽  
3D Models ◽  
Long Bone ◽  
Homogeneous Material ◽  
Long Bones ◽  
Bone Properties ◽  
Stiffness Properties ◽  
Mode 2 ◽  
Experimental Values

Where heterogeneous material considerations may yield more accurate estimates of long bones’ modal characteristics, homogeneous description has the advantage for yielding faster approximate solutions. In this study, modal frequencies of (bovine) long tibia bones are numerically estimated using the finite element method (FEM) using ANSYS starting from anatomically accurate CT scans and 3D models. Whole long bones are segmented into their cortical and cancellous constituents based on Hounsfield (HU) values. Bones’ cortical and cancellous constituents are first treated as heterogeneous material. Relative to stiffness-density relations, stiffness values are assigned for each element yielding a stiffness-graded structure. Modal frequencies are generated and values compared to those measured from dynamic experiments. Analysis was repeated where bone properties are homogenized by averaging the stiffness properties of bone constituents. The resulting frequencies are compared with those of the heterogeneous stiffness-graded bones. As compared with measured experimental values of one control long bone, the heterogeneous material assumption returned good estimates of the frequency values in the CC plane with of +0.85 % for mode 1 and +10.66 % for mode 2. For homogeneous material assumption, underestimates were returned with error values of −13.25% and −0.13 % differences for mode 2. In the ML plane, heterogeneous material assumption returned good estimates of the frequency values with −8.89 % for mode 1 and + 1.01 % for mode 2. Homogeneous material assumption underestimated the frequency values with error of −20.52 % for mode 1 and −7.50 % for mode 2. Homogeneous simplifications yielded faster and more memory-efficient FEM runs with heterogeneous modal analysis requiring 1.5 more running time and twice the utilized memory.

Heterogeneous Versus Homogeneous Material Considerations in Determining the Modal Frequencies of Long Tibia Bones

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Reem A. Yassine ◽  
Mohammad Karim Elham ◽  
Samir Mustapha ◽  
Ramsey F. Hamade
Keyword(s):  
Three Dimensional ◽  
Heterogeneous Material ◽  
Approximate Solutions ◽  
3D Models ◽  
Long Bone ◽  
Homogeneous Material ◽  
Long Bones ◽  
Bone Properties ◽  
Mode 2 ◽  
Experimental Values

Where heterogeneous material considerations may yield more accurate estimates of long bones' modal characteristics, homogeneous description yields faster approximate solutions. Here, modal frequencies of (bovine) long tibia bones are numerically estimated using the finite element method (FEM) (ANSYS) starting from anatomically accurate computed tomography (CT) scans. Whole long bones are segmented into cortical and cancellous constituents based on Hounsfield (HU) values. Accurate three-dimensional (3D) models are consequently developed. Bones' cortical and cancellous constituents are first treated as heterogeneous material. Relative to stiffness–density relations, stiffness values are assigned for each element yielding a stiffness-graded structure. Calculated modal frequencies are compared to those measured from dynamic experiments. Analysis was repeated where bone properties are homogenized by averaging the stiffness properties of bone constituents. Compared with experimental values of one control long bone, the heterogeneous material assumption returned good estimates of the frequency values in the cranial–caudal (CC) plane with of +0.85% for mode 1 and +10.66% for mode 2. For homogeneous material assumption, underestimates were returned with error values of −13.25% and −0.13% differences for mode 2. In the medial–lateral (ML) plane, heterogeneous material assumption returned good frequency estimates with −8.89% for mode 1 and +1.01% for mode 2. Homogeneous material assumption underestimated the frequency values with error of −20.52% for mode 1 and −7.50% for mode 2. Homogeneous simplifications yielded faster and more memory-efficient FEM runs with heterogeneous modal analysis requiring 1.5 more running time and twice the utilized memory.

scholarly journals Collagen heterogeneity within different growth regions of long bones of rachitic and nonrachitic chicks

1972 ◽  
Vol 127 (4) ◽  
pp. 715-720 ◽  
Author(s):  
Bryan P. Toole ◽  
Andrew H. Kang ◽  
Robert L. Trelstad ◽  
Jerome Gross
Keyword(s):  
Vitamin D ◽  
Amino Acid ◽  
Bone Matrix ◽  
Bone Collagen ◽  
Long Bone ◽  
Long Bones ◽  
Collagen Structure ◽  
Collagen Molecules ◽  
Relationship Of ◽  
Chain Type

The different anatomical regions involved in osteogenesis in the chick long bone have been examined for heterogeneities in collagen structure that might relate to the mechanism of ossification. Experimentally induced lathyrism was employed to enhance collagen solubility, and vitamin D deficiency to allow accumulation of osteoid, the precursor of bone matrix. The extractable lathyritic collagens of the cartilaginous and osseous regions of growing long bones from rachitic and non-rachitic chicks were examined for α-chain type and amino acid composition. In both groups of animals the growth plate and cartilaginous regions of the epiphysis gave collagen molecules of the constitution [α1(II)]3, whereas the ossifying regions contained [α1(I)]2 α2. The degree of hydroxylation of the lysine moieties was increased by approximately 50% in the α1(I)-chain and α2-chain of rachitic bone collagen. Since uncalcified osteoid is greatly enriched in rachitic bone, it is concluded that the collagen of osteoid has the configuration [α1(I)]2 α2, similar to that of bone matrix, but has an elevated hydroxylysine content. The possible relationship of this difference to the mechanism of calcification is discussed.

Longitudinal bone growth in vitro: effects of insulin-like growth factor I and growth hormone

1991 ◽  
Vol 124 (5) ◽  
pp. 602-607 ◽  
Author(s):  
Ben A. A. Scheven ◽  
Nicola J. Hamilton
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Bone Growth ◽  
Long Bone ◽  
Long Bones ◽  
Insulin Like Growth Factor ◽  
Serum Free ◽  
Factor I ◽  
Igf I

Abstract. Longitudinal growth was studied using an in vitro model system of intact rat long bones. Metatarsal bones from 18- and 19-day-old rat fetuses, entirely (18 days) or mainly (19 days) composed of chondrocytes, showed a steady rate of growth and radiolabelled thymidine incorporation for at least 7 days in serum-free media. Addition of recombinant human insulin-like growth factor-I to the culture media resulted in a direct stimulation of the longitudinal growth. Recombinant human growth hormone was also able to stimulate bone growth, although this was generally accomplished after a time lag of more than 2 days. A monoclonal antibody to IGF-I abolished both the IGF-I and GH-stimulated growth. However, the antibody had no effect on the growth of the bone explants in control, serum-free medium. Unlike the fetal long bones, bones from 2-day-old neonatal rats were arrested in their growth after 1-2 days in vitro. The neonatal bones responded to IGF-I and GH in a similar fashion as the fetal bones. Thus in this study in vitro evidence of a direct effect of GH on long bone growth via stimulating local production of IGF by the growth plate chondrocytes is presented. Furthermore, endogenous growth factors, others than IGFs, appear to play a crucial role in the regulation of fetal long bone growth.

scholarly journals Exposure to the RXR agonist SR11237 in early life causes disturbed skeletal morphogenesis in a rat model

2019 ◽  
Author(s):  
Holly Dupuis ◽  
Michael Andrew Pest ◽  
Ermina Hadzic ◽  
Thin Xuan Vo ◽  
Daniel B. Hardy ◽  
...  
Keyword(s):  
Growth Plate ◽  
Bone Growth ◽  
Long Bone ◽  
Tunel Staining ◽  
Long Bones ◽  
Micro Computed Tomography ◽  
Computed Tomography Scanning ◽  
Calcified Tissue ◽  
Trap Staining ◽  
Tomography Scanning

AbstractLongitudinal bone growth occurs through endochondral ossification (EO), controlled by various signaling molecules. Retinoid X Receptor (RXR) is a nuclear receptor with important roles in cell death, development, and metabolism. However, little is known about its role in EO. In this study, the agonist SR11237 was used to evaluate RXR activation on EO.Rats given SR11237 from post-natal day 5 to 15 were harvested for micro-computed tomography scanning and histology. In parallel, newborn CD1 mouse tibiae were cultured with increasing concentrations of SR11237 for histological and whole mount evaluation.RXR agonist-treated rats were smaller than controls, and developed dysmorphia of the growth plate. Cells invading the calcified and dysmorphic growth plate appeared pre-hypertrophic in size and shape corresponding with P57 immunostaining. Additionally, SOX9 positive cells were found surrounding the calcified tissue. The epiphysis of SR11237 treated bones showed increased TRAP staining, and additional TUNEL staining at the osteo-chondral junction. MicroCT revealed morphological disorganization in the long bones of treated animals. Isolated mouse long bones treated with SR11237 grew significantly less than their DMSO controls.This study demonstrates that stimulation of the RXR receptor causes irregular ossification, premature closure of the growth plate, and disrupted long bone growth in rodent models.

scholarly journals The first report of direct skeletal attachment method applying for tibia prosthetic leg in a chicken by cortical screw

2019 ◽  
Vol 2 (3) ◽  
pp. 3-5
Author(s):  
Piyabongkarn Damrongdej
Keyword(s):  
Stainless Steel ◽  
Blood Loss ◽  
Endotracheal Tube ◽  
Surgical Procedure ◽  
Small Animal ◽  
Long Bone ◽  
Long Bones ◽  
First Report ◽  
Cortical Screw ◽  
Intramedullary Screw

This is the first report of successful method for direct skeletal attachment for invent tibia prosthetic leg in a chicken amputee by using 3.0 mm stainless steel cortical screw as an intramedullary bone stem for right tibia endoprosthesis leg part and using acrylic with some part of endotracheal tube as an exoprosthesis leg part. This surgery was performed in a chicken amputee without bone cement using. A chicken could stand and sometime walk after 15 days of surgery. No complication problem with a screw’s stump. This intramedullary bone stem technique by a screw can adapt using in other parts of long bone animal amputee. This technique can apply for invent endoprosthesis limb in other small animal amputees and can use intramedullary screw technique with other long bones such as femur, humerus, radius, and ulna because this technique uses only one stainless 316L screw so the surgery cost is not too much. The surgical procedure is not complicated and blood loss during surgery is not much so the risk for this technique is low.

Classification of Fractures of Long Bones in the Dog and Cat: Introduction and Clinical Application

1990 ◽  
Vol 03 (02) ◽  
pp. 41-50 ◽  
Author(s):  
M. Unger ◽  
P. M. Montavon ◽  
U. F. A. Heim
Keyword(s):  
Bone Fractures ◽  
Reliable Data ◽  
Long Bone ◽  
Small Animals ◽  
Long Bones ◽  
Coding System ◽  
Fracture Classification ◽  
Fracture Criteria ◽  
Filing System

AbstractA computer filing system for the classification of fractured long bones in dogs and cats is described. It includes definitions of terms and a method of classification, based on fracture criteria seen on radiographs. This fracture classification was adapted from the AO/ASIF classification in man, to accomodate the special requirements of small animals. The localization and morphology of fractures were characterized with defined conventional terms, in order to assign an alpha-numeric code to each fracture. This coding system may also be used for computer filing of the data. With this classification system, the fractures are ranked in increasing severity and complexity for the various anatomical locations. This provides some prognostic and therapeutic informations. The system was used to code 1038 radiographically documented long bone fractures in dogs and cats. The distribution of fractures, with regard to their localization and morphology, was recorded. The system was easy to apply and proved to be able to supply valuable and reliable data.A computer filing system for the classification of fractured long bones in dogs and cats is described.

Nondestructive Assessment of Growing Rat Tibial Mechanical Properties Under Three-Point Bending: A Microcomputed Tomography Based Finite Element Study

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Yann Zimmermann ◽  
Tanvir Mustafy ◽  
Isabelle Villemure
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Microcomputed Tomography ◽  
Model Verification ◽  
Long Bone ◽  
Prediction Errors ◽  
Micro Ct ◽  
Three Point Bending ◽  
Bone Properties ◽  
Growing Rat

Abstract Microcomputed tomography (micro-CT) based finite element models (FEM) are efficient tools to assess bone mechanical properties. Although they have been developed for different animal models, there is still a lack of data for growing rat long bone models. This study aimed at developing and calibrating voxel-based FEMs using micro-CT scans and experimental data. Twenty-four tibiae were extracted from rats aged 28, 56, and 84 days old (d.o.) (n = 8/group), and their stiffness values were evaluated using three-point bending tests. Prior to testing, tibiae were scanned, reconstructed, and converted into FEM composed of heterogeneous bone properties based on pixel grayscales. Three element material laws (one per group) were calibrated using back-calculation process based on experimental bending data. Two additional specimens per group were used for model verification. The calibrated rigidity–density (E-ρ) relationships were different for each group: E28 = 10,320·ρash3.45; E56 = 43,620·ρash4.41; E84 = 20,090·ρash2.0. Obtained correlations between experimental and FEM stiffness values were 0.43, 0.10, and 0.66 with root-mean-square error (RMSE) of 14.4%, 17.4%, and 15.2% for 28, 56, and 84 d.o. groups, respectively. Prediction errors were less than 13.5% for 28 and 84 d.o. groups but reached 57.1% for the 56 d.o. group. Relationships between bone physical and mechanical properties were found to change during the growth, similarly to bending stiffness values, which increased with bone development. The reduced correlation observed for the 56 d.o. group may be related to the pubescent transition at that age group. These FE models will be useful for investigation of bone behavior in growing rats.

Test Methods for Accurate and Robust Material Property Measurements of Rodent Cortical Bone

2008 ◽  
Author(s):  
Douglas J. Adams ◽  
Svetlana Lublinsky ◽  
Mauricio Barrero
Keyword(s):  
Cortical Bone ◽  
Material Property ◽  
Statistical Power ◽  
Test Methods ◽  
Standard Test ◽  
Long Bone ◽  
Long Bones ◽  
Tissue Properties ◽  
Serial Test ◽  
Direct Measurements

Direct measurements of cortical bone material properties are difficult to achieve in rodent long bones due to the inherently small dimensions and difficulties in machining standard test specimen geometries [1]. Bone tissue properties in nearly all rodent studies are thus limited to estimates from flexural tests of long bone diaphyses. In addition to the inaccuracies imposed by the bending stress state itself, these material property estimates are further confounded by the non-uniform geometry of long bones along the diaphyseal length. The goal of this work was to develop a series of techniques to improve the accuracy and precision of material property measurements in rodent long bones, with explicit mathematical correction for geometrical complexity and multiple measurements from individual bones. In combination, these techniques provide a pragmatic serial test routine for collecting multiple direct measurements of cortical tissue elastic modulus and strength, with a potential for improving sensitivity and statistical power in skeletal studies using rodents.

scholarly journals Feasibility of three-dimensional reconstruction and automated measurement of fetal long bones using 5D Long Bone

2015 ◽  
Vol 58 (4) ◽  
pp. 268 ◽  
Author(s):  
Hyewon Hur ◽  
Young Han Kim ◽  
Hee Young Cho ◽  
Yong Won Park ◽  
Hye-Sung Won ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Long Bone ◽  
Long Bones ◽  
Automated Measurement ◽  
Three Dimensional Reconstruction ◽  
Dimensional Reconstruction

scholarly journals The Difference between Growth Factor Expression after Single and Multiple Fractures: Preliminary Results in Human Fracture Healing

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Harald Binder ◽  
Stefan Eipeldauer ◽  
Markus Gregori ◽  
Leonard Höchtl-Lee ◽  
Anita Thomas ◽  
...  
Keyword(s):  
Growth Factor ◽  
Bone Healing ◽  
Transforming Growth Factor ◽  
Serum Levels ◽  
Long Bone ◽  
Long Bones ◽  
Serum Concentrations ◽  
Multiple Fractures ◽  
Fracture Group ◽  
Significant Difference

Objectives.Circulating levels of VEGF-A (Vascular Endothelia Growth Factor-A), TGF-β1 (Transforming Growth Factor-beta 1), and M-CSF (Macrophage-Colony Stimulating Factor) were found to be predictors of bone healing and therefore prognostic criteria of delayed bone healing or nonunion. The aim of this study was to evaluate a potential rise of these markers in patients with multiple fractures of long bones compared to patients with single fractured long bone.Methods.92 patients were included in the study and finally after excluding all female patients 45 male patients were left for final analysis and divided into the single or multiple fracture group. TGF-β1, M-CSF, and VEGF-A serum levels were analysed over a time period of two weeks.Results.MCSF serum concentrations were higher in the group with multiple fractures as also TGF-β1 serum concentrations were at one and two weeks after trauma. No statistically significant difference was observed in the VEGF-A serum concentrations of both groups at either measurement point.Conclusion.We did observe a correlation between the quantity of the M-CSF and TGF-β1 expressions in serum and the number of fractured bones; surprisingly there was no statistically significant difference in the serum levels between patients with single and multiple fractures of long bones.

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