The interaction of microstructure and volume fraction in predicting failure in cancellous bone

Bone ◽  
2006 ◽  
Vol 39 (6) ◽  
pp. 1196-1202 ◽  
Author(s):  
Ara Nazarian ◽  
Martin Stauber ◽  
David Zurakowski ◽  
Brian D. Snyder ◽  
Ralph Müller
Keyword(s):  
Cancellous Bone ◽  
Volume Fraction

scholarly journals Role of estrogen receptor signaling in skeletal response to leptin in female ob/ob mice

2017 ◽  
Vol 233 (3) ◽  
pp. 357-367 ◽  
Author(s):  
Russell T Turner ◽  
Kenneth A Philbrick ◽  
Amida F Kuah ◽  
Adam J Branscum ◽  
Urszula T Iwaniec
Keyword(s):  
Estrogen Receptor ◽  
Cancellous Bone ◽  
Bone Growth ◽  
Volume Fraction ◽  
Gonadal Hormones ◽  
Uterine Weight ◽  
Bone Formation Rate ◽  
Longitudinal Bone Growth ◽  
Gonadal Dysfunction

Leptin, critical in regulation of energy metabolism, is also important for normal bone growth, maturation and turnover. Compared to wild type (WT) mice, bone mass is lower in leptin-deficient ob/ob mice. Osteopenia in growing ob/ob mice is due to decreased bone accrual, and is associated with reduced longitudinal bone growth, impaired cancellous bone maturation and increased marrow adipose tissue (MAT). However, leptin deficiency also results in gonadal dysfunction, disrupting production of gonadal hormones which regulate bone growth and turnover. The present study evaluated the role of increased estrogen in mediating the effects of leptin on bone in ob/ob mice. Three-month-old female ob/ob mice were randomized into one of the 3 groups: (1) ob/ob + vehicle (veh), (2) ob/ob + leptin (leptin) or (3) ob/ob + leptin and the potent estrogen receptor antagonist ICI 182,780 (leptin + ICI). Age-matched WT mice received vehicle. Leptin (40 µg/mouse, daily) and ICI (10 µg/mouse, 2×/week) were administered by subcutaneous injection for 1 month and bone analyzed by X-ray absorptiometry, microcomputed tomography and static and dynamic histomorphometry. Uterine weight did not differ between ob/ob mice and ob/ob mice receiving leptin + ICI, indicating that ICI successfully blocked the uterine response to leptin-induced increases in estrogen levels. Compared to leptin-treated ob/ob mice, ob/ob mice receiving leptin + ICI had lower uterine weight; did not differ in weight loss, MAT or bone formation rate; and had higher longitudinal bone growth rate and cancellous bone volume fraction. We conclude that increased estrogen signaling following leptin treatment is dispensable for the positive actions of leptin on bone and may attenuate leptin-induced bone growth.

Directional Tortuosity as a Predictor of Modulus Damage for Vertebral Cancellous Bone

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
David P. Fyhrie ◽  
Roger Zauel
Keyword(s):  
Mechanical Properties ◽  
Cancellous Bone ◽  
Volume Fraction ◽  
Compressive Strain ◽  
Effective Modulus ◽  
Hard Tissue ◽  
Bone Volume Fraction ◽  
Tissue Microstructure ◽  
Induced Changes ◽  
Effective Mechanical Properties

There are many methods used to estimate the undamaged effective (apparent) moduli of cancellous bone as a function of bone volume fraction (BV/TV), mean intercept length (MIL), and other image based average microstructural measures. The MIL and BV/TV are both only functions of the cancellous microstructure and, therefore, cannot directly account for damage induced changes in the intrinsic trabecular hard tissue mechanical properties. Using a nonlinear finite element (FE) approximation for the degradation of effective modulus as a function of applied effective compressive strain, we demonstrate that a measurement of the directional tortuosity of undamaged trabecular hard tissue strongly predicts directional effective modulus (r2 > 0.90) and directional effective modulus degradation (r2 > 0.65). This novel measure of cancellous bone directional tortuosity has the potential for development into an anisotropic approach for calculating effective mechanical properties as a function of trabecular level material damage applicable to understanding how tissue microstructure and intrinsic hard tissue moduli interact to determine cancellous bone quality.

Misalignment Error in Cancellous Bone Apparent Elastic Modulus Depends on Bone Volume Fraction and Degree of Anisotropy

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Matthew B. L. Bennison ◽  
A. Keith Pilkey ◽  
W. Brent Lievers
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Cancellous Bone ◽  
Volume Fraction ◽  
Experimental Studies ◽  
Bone Volume ◽  
Bone Volume Fraction ◽  
Skeletal Site ◽  
Degree Of Anisotropy ◽  
Misalignment Error

Abstract Cancellous bone is an anisotropic structure with architectural and mechanical properties that vary due to both skeletal site and disease state. This anisotropy means that, in order to accurately and consistently measure the mechanical properties of cancellous bone, experiments should be performed along the primary mechanical axis (PMA), that is, the orientation in which the mechanical properties are at their maximum value. Unfortunately, some degree of misalignment will always be present, and the magnitude of the resulting error is expected to be architecture dependent. The goal of this work is to quantify the dependence of the misalignment error, expressed in terms of change in apparent elastic modulus (ΔE), on both the bone volume fraction (BV/TV) and the degree of anisotropy (DA). Finite element method (FEM) models of bovine cancellous bone from five different skeletal sites were created at 5 deg and 20 deg from the PMA determined for each region. An additional set of models was created using image dilation/erosion steps in order to control for BV/TV and better isolate the effect of DA. Misalignment error was found to increase with increasing DA and decreasing BV/TV. At 5 deg misaligned from the PMA, error is relatively low (<5%) in all cases but increases to 8–24% error at 20 deg. These results suggest that great care is needed to avoid introducing misalignment error into experimental studies, particularly when studying regions with high anisotropy and/or low bone volume fraction, such as vertebral or osteoporotic bone.

scholarly journals Structural strength of cancellous specimens from bovine femur under cyclic compression

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1562 ◽  
Author(s):  
Kaori Endo ◽  
Satoshi Yamada ◽  
Masahiro Todoh ◽  
Masahiko Takahata ◽  
Norimasa Iwasaki ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Yield Stress ◽  
Bone Strength ◽  
Cancellous Bone ◽  
Structural Model ◽  
Volume Fraction ◽  
Bone Structure ◽  
Micro Computed Tomography ◽  
Bone Volume Fraction ◽  
Structural Deterioration

The incidence of osteoporotic fractures was estimated as nine million worldwide in 2000, with particular occurrence at the proximity of joints rich in cancellous bone. Although most of these fractures spontaneously heal, some fractures progressively collapse during the early post-fracture period. Prediction of bone fragility during progressive collapse following initial fracture is clinically important. However, the mechanism of collapse, especially the gradual loss of the height in the cancellous bone region, is not clearly proved. The strength of cancellous bone after yield stress is difficult to predict since structural and mechanical strength cannot be determineda priori. The purpose of this study was to identify whether the baseline structure and volume of cancellous bone contributed to the change in cancellous bone strength under cyclic loading. A total of fifteen cubic cancellous bone specimens were obtained from two 2-year-old bovines and divided into three groups by collection regions: femoral head, neck, and proximal metaphysis. Structural indices of each 5-mm cubic specimen were determined using micro-computed tomography. Specimens were then subjected to five cycles of uniaxial compressive loading at 0.05 mm/min with initial 20 N loading, 0.3 mm displacement, and then unloading to 0.2 mm with 0.1 mm displacement for five successive cycles. Elastic modulus and yield stress of cancellous bone decreased exponentially during five loading cycles. The decrease ratio of yield stress from baseline to fifth cycle was strongly correlated with bone volume fraction (BV/TV,r= 0.96,p< 0.01) and structural model index (SMI,r= − 0.81,p< 0.01). The decrease ratio of elastic modulus from baseline to fifth cycle was also correlated with BV/TV (r= 0.80,p< 0.01) and SMI (r= − 0.78,p< 0.01). These data indicate that structural deterioration of cancellous bone is associated with bone strength after yield stress. This study suggests that baseline cancellous bone structure estimated from adjacent non-fractured bone contributes to the cancellous bone strength during collapse.

Effect of Microcomputed Tomography Voxel Size on the Finite Element Model Accuracy for Human Cancellous Bone

2005 ◽  
Vol 127 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Yener N. Yeni ◽  
Gregory T. Christopherson ◽  
X. Neil Dong ◽  
Do-Gyoon Kim ◽  
David P. Fyhrie
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Boundary Conditions ◽  
Cancellous Bone ◽  
Coefficient Of Variation ◽  
Volume Fraction ◽  
Bone Volume ◽  
Bone Volume Fraction ◽  
Voxel Size ◽  
Fixed End

The level of structural detail that can be acquired and incorporated in a finite element (FE) analysis might greatly influence the results of microcomputed tomography (μCT)-based FE simulations, especially when relatively large bones, such as whole vertebrae, are of concern. We evaluated the effect of scanning and reconstruction voxel size on the μCT-based FE analyses of human cancellous tissue samples for fixed- and free-end boundary conditions using different combinations of scan/reconstruction voxel size. We found that the bone volume fraction (BV/TV) did not differ considerably between images scanned at 21 and 50 μm and reconstructed at 21, 50, or 110 μm (−0.5% to 7.8% change from the 21/21 μm case). For the images scanned and reconstructed at 110 μm, however, there was a large increase in BV/TV compared to the 21/21 μm case (58.7%). Fixed-end boundary conditions resulted in 1.8% [coefficient of variation (COV)] to 14.6% (E) difference from the free-end case. Dependence of model output parameters on scanning and reconstruction voxel size was similar between free- and fixed-end simulations. Up to 26%, 30%, 17.8%, and 32.3% difference in modulus (E), and average (VMExp), standard deviation (VMSD) and coefficient of variation (COV) of von Mises stresses, respectively, was observed between the 21/21 μm case and other scan/reconstruction combinations within the same (free or fixed) simulation group. Observed differences were largely attributable to scanning resolution, although reconstruction resolution also contributed significantly at the largest voxel sizes. All 21/21 μm results (taken as the gold standard) could be predicted from the 21/50 radj2=0.91-0.99;p<0.001, 21/110 radj2=0.58-0.99;p<0.02 and 50/50 results radj2=0.61-0.97;p<0.02. While BV/TV, VMSD, and VMExp/σz from the 21/21 could be predicted by those from the 50/110 radj2=0.63-0.93;p<0.02 and 110/110 radj2=0.41-0.77;p<0.05 simulations as well, prediction of E, VMExp, and COV became marginally significant 0.04<p<0.13 at 50/110 and nonsignificant at 110/110 0.21<p<0.70. In conclusion, calculation of cancellous bone modulus, mean trabecular stress, and other parameters are subject to large errors at 110/110 μm voxel size. However, enough microstructural details for studying bone volume fraction, trabecular shear stress scatter, and trabecular shear stress amplification VMExp/σz can be resolved using a 21/110 μm, 50/110 μm, and 110/110 μm voxels for both free- and fixed-end constraints.

Prediction of Mechanical Properties of the Cancellous Bone of the Mandibular Condyle

2003 ◽  
Vol 82 (10) ◽  
pp. 819-823 ◽  
Author(s):  
L.J. van Ruijven ◽  
E.B.W. Giesen ◽  
M. Farella ◽  
T.M.G.J. van Eijden
Keyword(s):  
Mechanical Properties ◽  
Cancellous Bone ◽  
Volume Fraction ◽  
Bone Structure ◽  
Structural Parameters ◽  
Mandibular Condyle ◽  
Element Model ◽  
Micro Computed Tomography ◽  
Bone Volume Fraction ◽  
Apparent Stiffness

The mechanical properties of cancellous bone depend on the bone structure. The present study examined the extent to which the apparent stiffness of the cancellous bone of the human mandibular condyle can be predicted from its structure. Two models were compared. The first, a structure model, used structural parameters such as bone volume fraction and anisotropy to estimate the apparent stiffness. The second was a finite element model (FEM) of the cancellous bone. The bone structure was characterized by micro-computed tomography. The calculated stiffnesses of 24 bone samples were compared with measured stiffnesses. Both models could predict 89% of the variation in the measured stiffnesses. From the stiffness approximated by FEM in combination with the measured stiffness, the stiffness of the bone tissue was estimated to be 11.1 ± 3.2 GPa. It was concluded that both models could predict the stiffness of cancellous bone with adequate accuracy.

scholarly journals Thermoneutral housing attenuates premature cancellous bone loss in male C57BL/6J mice

2019 ◽  
Vol 8 (11) ◽  
pp. 1455-1467 ◽  
Author(s):  
Stephen A Martin ◽  
Kenneth A Philbrick ◽  
Carmen P Wong ◽  
Dawn A Olson ◽  
Adam J Branscum ◽  
...  
Keyword(s):  
Bone Loss ◽  
Cancellous Bone ◽  
Room Temperature ◽  
Type I Collagen ◽  
Distal Femur ◽  
Volume Fraction ◽  
Lumbar Vertebra ◽  
Published Data ◽  
Type I ◽  
Housing Temperature

Mice are a commonly used model to investigate aging-related bone loss but, in contrast to humans, mice exhibit cancellous bone loss prior to skeletal maturity. The mechanisms mediating premature bone loss are not well established. However, our previous work in female mice suggests housing temperature is a critical factor. Premature cancellous bone loss was prevented in female C57BL/6J mice by housing the animals at thermoneutral temperature (where basal rate of energy production is at equilibrium with heat loss). In the present study, we determined if the protective effects of thermoneutral housing extend to males. Male C57BL/6J mice were housed at standard room temperature (22°C) or thermoneutral (32°C) conditions from 5 (rapidly growing) to 16 (slowly growing) weeks of age. Mice housed at room temperature exhibited reductions in cancellous bone volume fraction in distal femur metaphysis and fifth lumbar vertebra; these effects were abolished at thermoneutral conditions. Mice housed at thermoneutral temperature had higher levels of bone formation in distal femur (based on histomorphometry) and globally (serum osteocalcin), and lower global levels of bone resorption (serum C-terminal telopeptide of type I collagen) compared to mice housed at room temperature. Thermoneutral housing had no impact on bone marrow adiposity but resulted in higher abdominal white adipose tissue and serum leptin. The overall magnitude of room temperature housing-induced cancellous bone loss did not differ between male (current study) and female (published data) mice. These findings highlight housing temperature as a critical experimental variable in studies using mice of either sex to investigate aging-related changes in bone metabolism.

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