scholarly journals A Logarithmic Formulation for Anisotropic Behavior Characterization of Bovine Cortical Bone Tissue in Long Bones Undergoing Uniaxial Compression at Different Speeds

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5045
Author(s):  
Abdallah Shokry ◽  
Hasan Mulki ◽  
Ghais Kharmanda
Keyword(s):  
Mechanical Properties ◽  
Cortical Bone ◽  
Bone Tissue ◽  
Uniaxial Compression ◽  
Failure Stress ◽  
Prosthesis Design ◽  
Long Bones ◽  
Anisotropic Behavior ◽  
Tangential Directions

The mechanical properties of bone tissues change significantly within the bone body, since it is considered as a heterogeneous material. The characterization of bone mechanical properties is necessary for many studies, such as in prosthesis design. An experimental uniaxial compression study is carried out in this work on bovine cortical bone tissue in long bones (femur and tibia) at several speeds to characterize its anisotropic behavior. Several samples from different regions are taken, and the result selection is carried out considering the worst situations and failure modes. When considering different displacement rates (from 0.5 to 5 mm/min), three findings are reported: The first finding is that the behavior of bone tissues in radial and tangential directions are almost similar, which allows us to consider the transversal isotropic behavior under static loads as well as under dynamic loads. The second finding is that the failure stress values of the longitudinal direction is much higher than those of the radial and tangential directions at low displacement rates, while there is no big difference at the high displacement rates. The third finding is a new mathematical model that relates the dynamic failure stress with the static one, considering the displacement rates. This model is validated by experimental results. The model can be effectively used in reliability and optimization analysis in prosthesis design, such as hip prosthesis.

scholarly journals Characterization of the effects of x-ray irradiation on the hierarchical structure and mechanical properties of human cortical bone

Biomaterials ◽  
2011 ◽  
Vol 32 (34) ◽  
pp. 8892-8904 ◽  
Author(s):  
Holly D. Barth ◽  
Elizabeth A. Zimmermann ◽  
Eric Schaible ◽  
Simon Y. Tang ◽  
Tamara Alliston ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cortical Bone ◽  
Hierarchical Structure ◽  
X Ray ◽  
Human Cortical Bone ◽  
The Hierarchical Structure

scholarly journals Analysis of Mechanical Properties and Mechanical Anisotropy in Canine Bone Tissues of Various Ages

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Changqi Luo ◽  
Junyi Liao ◽  
Zhenglin Zhu ◽  
Xiaoyu Wang ◽  
Xiao Lin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Cortical Bone ◽  
Bone Tissue ◽  
Poisson Ratio ◽  
Age Groups ◽  
Distal Region ◽  
Mechanical Anisotropy ◽  
Age Group ◽  
Cross Sectional

The effect of age on mechanical behavior and microstructure anisotropy of bone is often ignored by researchers engaged in the study of biomechanics. The objective of our study was to determine the variations in mechanical properties of canine femoral cortical bone with age and the mechanical anisotropy between the longitudinal and transverse directions. Twelve beagles divided into three age groups (6, 12, and 36 months) were sacrificed and all femurs were extracted. The longitudinal and transverse samples of cortical bone were harvested from three regions of diaphysis (proximal, central, and distal). A nanoindentation technique was used for simultaneously measuring force and displacement of a diamond tip pressed 2000nm into the hydrated bone tissue. An elastic modulus was calculated from the unloading curve with an assumed Poisson ratio of 0.3, while hardness was defined as the maximal force divided by the corresponding contact area. The mechanical properties of cortical bone were determined from 852 indents on two orthogonal cross-sectional surfaces. Mean elastic modulus ranged from 7.56±0.32 GPa up to 21.56±2.35 GPa, while mean hardness ranged from 0.28±0.057 GPa up to 0.84±0.072 GPa. Mechanical properties of canine femoral cortical bone tended to increase with age, but the magnitudes of these increase for each region might be different. The longitudinal mechanical properties were significantly higher than that of transverse direction (P<0.01). A significant anisotropy was found in the mechanical properties while there was no significant correlation between the two orthogonal directions in each age group (r2<0.3). Beyond that, the longitudinal mechanical properties of the distal region in each age group were lower than the proximal and central regions. Hence, mechanical properties in nanostructure of bone tissue must differ mainly among age, sample direction, anatomical sites, and individuals. These results may help a number of researchers develop more accurate constitutive micromechanics models of bone tissue in future studies.

Fabrication and characterization of electrospinning/3D printing bone tissue engineering scaffold

RSC Advances ◽  
2016 ◽  
Vol 6 (112) ◽  
pp. 110557-110565 ◽  
Author(s):  
Yinxian Yu ◽  
Sha Hua ◽  
Mengkai Yang ◽  
Zeze Fu ◽  
Songsong Teng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
3D Printing ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Composite Scaffold ◽  
Tissue Engineering Scaffold ◽  
Fabrication And Characterization

A composite scaffold was fabricated with a method involving both electrospinning and 3D printing to give microscale pores and good mechanical properties. Biocompatibility and cell infiltration on the scaffold was evaluated by an in vitro study.

scholarly journals Comparative analysis of stress-strain state of mathematical models for an individual endoprosthesis and allocomposite endoprosthesis in case of replacement of long bone defects

TRAUMA ◽  
2021 ◽  
Vol 22 (4) ◽  
pp. 37-45
Author(s):  
O.E. Vyrva ◽  
Ya.О. Golovina ◽  
R.V. Malik ◽  
M.Yu. Karpinsky ◽  
О.V. Yaresko
Keyword(s):  
Mathematical Models ◽  
Bone Cement ◽  
Cortical Bone ◽  
Bone Tissue ◽  
Bone Grafting ◽  
Long Bone ◽  
Long Bones ◽  
Rigid Support ◽  
Stress Strain ◽  
Complete Replacement

Background. Replacement of post-resection defects of long bones in case of a tumor process is always an urgent problem of orthopedics. Among the wide variety of materials and methods for reconstruction of post-resection defects of long bones, the most common are individual, modular arthroplasty and bioreconstructive interventions. To study the mechanical properties of the structures we have chosen, various types of post-resection femoral bone defect replacement were simulated using the finite element method. The purpose was to compare the data on stress-strain states in mathematical models “allocomposite endoprosthesis” and “individual endoprosthesis” of the proximal femur. Material and methods. Mathematical models of the femur with the formation of a post-resection proximal defect replaced by a segmental bone allograft in combination with an individual endoprosthesis have been created. The model is presented in two versions, with the formation of transverse and step-cut osteotomy. Each model was examined separately with cement and cementless attachment in the area of the endoprosthesis stem. For comparison, we chose a model with complete replacement of the proximal end of the femur with an individual endoprosthesis without bone grafting. Results. Femur step-cut osteotomy can significantly reduce the level of stress in the osteotomy area. This is due to the fact that performing the step-cut osteotomy allows the bone fragments to provide resistance to shearing movement. The use of bone cement can significantly reduce the level of stress around the stem of the endoprosthesis in both variants of femoral osteotomy (transverse and step-cut). This is due to the fact that bone cement, which has an elastic modulus at an intermediate value between titanium and bone tissue, forms a layer between them, performs a damper function, that smoothes the difference in deformation values of the metal and bone tissue, thereby reducing the level of stress in them. Arthroplasty without performing bone grafting leads to increased stresses in the bone tissue due to the presence of a rigid support on the cortical bone endoprosthesis in the diaphysis along the line of its resection. Conclusions. Performing step-cut osteotomy of the femur reduces the level of mechanical stresses in the osteotomy area by half compared to models with transverse osteotomy, which is of particular importance in the early postoperative stages. The use of bone cement for fixing the stem of the endoprosthesis can also significantly reduce the level of stress in all variants of the studied models, due to the formation of a damping layer between the metal and the bone tissue. The level of stress in models without bone grafting does not depend on the use of bone cement, but is determined by the presence of a rigid support of the endoprosthesis on the cortical bone along the line of its resection.

Characterization of the mechanical properties of bovine cortical bone treated with a novel tissue sterilization process

2010 ◽  
Vol 12 (4) ◽  
pp. 273-279 ◽  
Author(s):  
Nathan Kemper ◽  
Noel Davison ◽  
Daniel Fitzpatrick ◽  
Rebecca Marshall ◽  
Albert Lin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cortical Bone ◽  
Sterilization Process

Electro-Mechanical Behavior of Wet Bone—Part II: Wave Propagation

1984 ◽  
Vol 106 (3) ◽  
pp. 262-271 ◽  
Author(s):  
N. Guzelsu ◽  
S. Saha
Keyword(s):  
Mechanical Properties ◽  
Wave Propagation ◽  
Bone Tissue ◽  
Electrical Conduction ◽  
Flexural Wave ◽  
Long Bones ◽  
Induction Vector ◽  
Mechanical Wave ◽  
Flexural Wave Propagation ◽  
Dry Bone

In this study, a general mixture model, which was developed for wet bone, has been used to analyze the flexural wave propagation in long bones. The electrical conduction is taken into account as well as the piezo-electric properties of bone tissue. The general formulation is simplified and certain assumptions made to yield a particular set of equations. The solution of the magnetic induction vector outside the bone due to the mechanical wave propagation is obtained. The results are compared with a similar problem using dry bone. The results indicate that the electro-mechanical properties of bone tissue could be used for monitoring the rate of fracture healing in long bones.

scholarly journals Karakterisasi biokomposit sheep hydroxyapatite (sha)/shellac/tepung terigu

2019 ◽  
Vol 17 (2) ◽  
Author(s):  
Izmi Mahfudi ◽  
Joko Triyono ◽  
Teguh Triyono
Keyword(s):  
Mechanical Properties ◽  
Bone Tissue ◽  
Wheat Flour ◽  
Diffraction Peak ◽  
X Ray Diffraction ◽  
Medical Field ◽  
Forming Process ◽  
X Ray ◽  
Bone Powder

The development of science and technology has led to new inovations in the medical field, especially ortopedic. The aim of those inovations is to find the alternatives of good materials that can replace the broken sturcture of bone tissue. One of the innovations conducted is the characterization of sheep hydroxyapatite biocomposite. This study aims to investigate the mechanical properties of the material Sheep Hydroxyapatite (SHA) / shellac / wheat fluor. Sheep bone powder already gained from the crusher process and meshing into size of 100 and are soaked for 24 hours, then mixed with wheat flour with the ratio 30 : 70 %wt, 40 : 60 %wt, 50 : 50 %wt, 60 : 40 %wt, 70 : 30 %wt. The next step is the forming process and calcination at a temperature of 900oC with a increase of 10 °C/min. Results of X-Ray Diffraction (XRD) shows that the diffraction peak of SHA/shellac/wheat flour is the value of 2θ: 32.0747º, 33.1943º, 32.5338º. The lowest hardness number of SHA/shellac/wheat flour is 2.86 VHN and the highest is 14.80 VHN, also the highest strong pressure number is 0.20 MPa. The result of microscophy at observation using SEM shows Thar the SHA/shellac/wheat flour 50:50 % wt sample has more porosity as.

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