scholarly journals Growth and development of trabecular structure in the calcaneus of Japanese macaques (Macaca fuscata) reflects locomotor behavior, life-history, and neuromuscular development.

2021 ◽  
Author(s):  
Jaap PP Saers ◽  
Adam D Gordon ◽  
Timothy M Ryan ◽  
Jay T Stock
Keyword(s):  
Life History ◽  
Volume Fraction ◽  
Bone Structure ◽  
Japanese Macaques ◽  
Trabecular Structure ◽  
Bone Volume Fraction ◽  
Cross Sectional ◽  
Related Variation ◽  
Age Related ◽  
Neuromuscular Development

We aim to broaden the analysis of bone structure by suggesting a new way to incorporate the interactions between behavior, neuromuscular development, and life-history. We examine the associations between these variables and age-related variation in trabecular structure in the calcaneus of Japanese macaques (Macaca fuscata). If skeletal markers linking these variables can be established, our inferences of the biology and behavior of fossil species would be significantly improved. We μCT scanned the calcaneus in a cross-sectional sample of 36 juveniles aged between 0 and 7 years old and 5 adults at the Primate Research Institute, Japan. We calculated whole bone averages of standard trabecular properties and generated whole-bone morphometric maps of bone volume fraction and Youngs modulus. Trabecular structure is increasingly heterogeneous in older individuals. BV/TV decreases during the first month of life and increases afterwards, coinciding with the onset of independent locomotion. At birth, primary Youngs modulus is oriented orthogonal to the ossification center, but after locomotor onset bone structure becomes stiffest in the direction of joint surfaces and muscle attachments. Age-related variation in bone volume fraction is best predicted by an interaction between neuromaturation, body mass, and locomotor independence. Results support the common assumption that trabecular structure dynamically adapts to novel joint loading conditions during ontogeny. The timing of independent locomotion, body size, and neuromuscular development, are all correlated to age-related variation in the trabecular structure of the macaque calcaneus. The causal mechanisms behind the observed patterns cannot be directly inferred from our cross-sectional study. If the model presented in this paper holds up under longitudinal experimental conditions, trabecular structure can be used both to infer behavior from fossil morphology and to serve as a valuable proxy for neuromuscular maturation and life history events like locomotor onset and the achievement of an adult-like gait.

scholarly journals Gracility of the modern Homo sapiens skeleton is the result of decreased biomechanical loading

2014 ◽  
Vol 112 (2) ◽  
pp. 372-377 ◽  
Author(s):  
Timothy M. Ryan ◽  
Colin N. Shaw
Keyword(s):  
Physical Activity ◽  
Trabecular Bone ◽  
Proximal Femur ◽  
Volume Fraction ◽  
Bone Structure ◽  
Homo Sapiens ◽  
Trabecular Bone Structure ◽  
Human Populations ◽  
Bone Volume Fraction ◽  
Age Related

The postcranial skeleton of modern Homo sapiens is relatively gracile compared with other hominoids and earlier hominins. This gracility predisposes contemporary humans to osteoporosis and increased fracture risk. Explanations for this gracility include reduced levels of physical activity, the dissipation of load through enlarged joint surfaces, and selection for systemic physiological characteristics that differentiate modern humans from other primates. This study considered the skeletal remains of four behaviorally diverse recent human populations and a large sample of extant primates to assess variation in trabecular bone structure in the human hip joint. Proximal femur trabecular bone structure was quantified from microCT data for 229 individuals from 31 extant primate taxa and 59 individuals from four distinct archaeological human populations representing sedentary agriculturalists and mobile foragers. Analyses of mass-corrected trabecular bone variables reveal that the forager populations had significantly higher bone volume fraction, thicker trabeculae, and consequently lower relative bone surface area compared with the two agriculturalist groups. There were no significant differences between the agriculturalist and forager populations for trabecular spacing, number, or degree of anisotropy. These results reveal a correspondence between human behavior and bone structure in the proximal femur, indicating that more highly mobile human populations have trabecular bone structure similar to what would be expected for wild nonhuman primates of the same body mass. These results strongly emphasize the importance of physical activity and exercise for bone health and the attenuation of age-related bone loss.

Ageing Changes in the Tensile Properties of Tendons: Influence of Collagen Fibril Volume Fraction

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
K. L. Goh ◽  
D. F. Holmes ◽  
H.-Y. Lu ◽  
S. Richardson ◽  
K. E. Kadler ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Collagen Fibril ◽  
Volume Fraction ◽  
Area Fraction ◽  
Sectional Area ◽  
Cross Sectional ◽  
P Values ◽  
Age Related ◽  
Fibril Diameter ◽  
Age Related Changes

Connective tissues are biological composites comprising of collagen fibrils embedded in (and reinforcing) the hydrated proteoglycan-rich (PG) gel within the extracellular matrices (ECMs). Age-related changes to the mechanical properties of tissues are often associated with changes to the structure of the ECM, namely, fibril diameter. However, quantitative attempts to correlate fibril diameter to mechanical properties have yielded inconclusive evidence. Here, we described a novel approach that was based on the rule of mixtures for fiber composites to evaluate the dependence of age-related changes in tendon tensile strength (σ) and stiffness (E) on the collagen fibril cross-sectional area fraction (ρ), which is related to the fibril volume fraction. Tail tendons from C57BL6 mice from age groups 1.6–35.3months old were stretched to failure to determine σ and E. Parallel measurements of ρ as a function of age were made using transmission electron microscopy. Mathematical models (rule of mixtures) of fibrils reinforcing a PG gel in tendons were used to investigate the influence of ρ on ageing changes in σ and E. The magnitudes of σ, E, and ρ increased rapidly from 1.6monthsto4.0months (P-values <0.05) before reaching a constant (age independent) from 4.0monthsto29.0months (P-values >0.05); this trend continued for E and ρ (P-values >0.05) from 29.0monthsto35.3months, but not for σ, which decreased gradually (P-values <0.05). Linear regression analysis revealed that age-related changes in σ and E correlated positively to ρ (P-values <0.05). Collagen fibril cross-sectional area fraction ρ is a significant predictor of ageing changes in σ and E in the tail tendons of C57BL6 mice.

scholarly journals Age-related variation in mobility independence among wheelchair users with spinal cord injury: A cross-sectional study

2016 ◽  
Vol 39 (2) ◽  
pp. 180-189 ◽  
Author(s):  
Timo Hinrichs ◽  
Veronika Lay ◽  
Ursina Arnet ◽  
Inge Eriks-Hoogland ◽  
Hans Georg Koch ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Wheelchair Users ◽  
Related Variation ◽  
Age Related ◽  
Cord Injury

scholarly journals Trabecular bone patterning in the hominoid distal femur

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5156 ◽  
Author(s):  
Leoni Georgiou ◽  
Tracy L. Kivell ◽  
Dieter H. Pahr ◽  
Matthew M. Skinner
Keyword(s):  
Trabecular Bone ◽  
Distal Femur ◽  
Volume Fraction ◽  
Reaction Force ◽  
Intraspecific Variability ◽  
Trabecular Structure ◽  
Trabecular Architecture ◽  
Micro Computed Tomography ◽  
Bone Volume Fraction ◽  
Distal Epiphysis

BackgroundIn addition to external bone shape and cortical bone thickness and distribution, the distribution and orientation of internal trabecular bone across individuals and species has yielded important functional information on how bone adapts in response to load. In particular, trabecular bone analysis has played a key role in studies of human and nonhuman primate locomotion and has shown that species with different locomotor repertoires display distinct trabecular architecture in various regions of the skeleton. In this study, we analyse trabecular structure throughout the distal femur of extant hominoids and test for differences due to locomotor loading regime.MethodsMicro-computed tomography scans ofHomo sapiens(n= 11),Pan troglodytes(n= 18),Gorilla gorilla(n= 14) andPongosp. (n= 7) were used to investigate trabecular structure throughout the distal epiphysis of the femur. We predicted that bone volume fraction (BV/TV) in the medial and lateral condyles inHomowould be distally concentrated and more anisotropic due to a habitual extended knee posture at the point of peak ground reaction force during bipedal locomotion, whereas great apes would show more posteriorly concentrated BV/TV and greater isotropy due to a flexed knee posture and more variable hindlimb use during locomotion.ResultsResults indicate some significant differences between taxa, with the most prominent being higher BV/TV in the posterosuperior region of the condyles inPanand higher BV/TV and anisotropy in the posteroinferior region inHomo. Furthermore, trabecular number, spacing and thickness differ significantly, mainly separatingGorillafrom the other apes.DiscussionThe trabecular architecture of the distal femur holds a functional signal linked to habitual behaviour; however, there was more similarity across taxa and greater intraspecific variability than expected. Specifically, there was a large degree of overlap in trabecular structure across the sample, andHomowas not as distinct as predicted. Nonetheless, this study offers a comparative sample of trabecular structure in the hominoid distal femur and can contribute to future studies of locomotion in extinct taxa.

Bone and muscle development in three inbred female mouse strains

2021 ◽  
Author(s):  
Ursula Föger-Samwald ◽  
Maria Papageorgiou ◽  
Katharina Wahl-Figlash ◽  
Katharina Kerschan-Schindl ◽  
Peter Pietschmann
Keyword(s):  
Trabecular Bone ◽  
Muscle Development ◽  
Bone Growth ◽  
Volume Fraction ◽  
Bone Structure ◽  
Bone Development ◽  
Mouse Strains ◽  
Structural Reorganization ◽  
Bone Volume Fraction ◽  
Trabecular Thickness

AbstractMuscle force is thought to be one of the main determinants of bone development. Hence, peak muscle growth is expected to precede peak bone growth. In this study, we investigated muscle and bone development in female C57BL/6 J, DBA/2JRj, and C3H/HeOuJ mice. Femoral cortical and trabecular bone structure and the weights of selected muscles were assessed at the ages of 8, 16, and 24 weeks. Muscle mass increased from 8 to 24 weeks in all 3 strains, suggesting peak muscle development at 24 weeks or later. Bone volume fraction, trabecular number, and connectivity density of the femur decreased or remained unchanged, whereas trabecular density and trabecular thickness largely increased. These results suggest a peak in trabecular bone accrual at 8 weeks or earlier followed by further increases in density and structural reorganization of trabeculae. Cortical density, cortical thickness, and cortical cross sectional area increased over time, suggesting a peak in cortical bone accrual at 24 weeks or later. In conclusion, our data provide evidence that growth of muscle lags behind trabecular bone accrual.

scholarly journals Targeted ablation of the PTH/PTHrP receptor in osteocytes impairs bone structure and homeostatic calcemic responses

2011 ◽  
Vol 209 (1) ◽  
pp. 21-32 ◽  
Author(s):  
William F Powell ◽  
Kevin J Barry ◽  
Irena Tulum ◽  
Tatsuya Kobayashi ◽  
Stephen E Harris ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Bone Structure ◽  
Micro Computed Tomography ◽  
Bone Volume Fraction ◽  
Blood Calcium ◽  
Low Calcium Diet ◽  
Exon 1 ◽  
Skeletal Homeostasis ◽  
Pthrp Receptor

Parathyroid hormone (PTH) is a major physiologic regulator of calcium, phosphorous, and skeletal homeostasis. Cells of the osteoblastic lineage are key targets of PTH action in bone, and recent evidence suggests that osteocytes might be important in the anabolic effects of PTH. To understand the role of PTH signaling through the PTH/PTHrP receptors (PPR) in osteocytes and to determine the role(s) of these cells in mediating the effects of the hormone, we have generated mice in which PPR expression is specifically ablated in osteocytes. Transgenic mice in which the 10 kb-Dmp1 promoter drives a tamoxifen-inducible Cre-recombinase were mated with animals in which exon 1 of PPR is flanked by lox-P sites. In these animals, osteocyte-selective PPR knockout (Ocy-PPRcKO mice) could be induced by administration of tamoxifen. Histological analysis revealed a reduction in trabecular bone and mild osteopenia in Ocy-PPRcKO mice. Reduction of trabeculae number and thickness was also detected by micro-computed tomography analysis whereas bone volume fraction (BV/TV%) was unchanged. These findings were associated with an increase in Sost and sclerostin expression. When Ocy-PPRcKO mice were subjected to a low-calcium diet to induce secondary hyperparathyroidism, their blood calcium levels were significantly lower than littermate controls. Moreover, PTH was unable to suppress Sost and sclerostin expression in the Ocy-PPRcKO animals, suggesting an important role of PTH signaling in osteocytes for proper bone remodeling and calcium homeostasis.

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.

Comparison of Mixed and Kinematic Uniform Boundary Conditions in Homogenized Elasticity of Femoral Trabecular Bone Using Microfinite Element Analyses

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Jarunan Panyasantisuk ◽  
Dieter H. Pahr ◽  
Thomas Gross ◽  
Philippe K. Zysset
Keyword(s):  
Boundary Conditions ◽  
Trabecular Bone ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Volume Fraction ◽  
Bone Fragility ◽  
Model Parameters ◽  
Bone Volume Fraction ◽  
Age Related ◽  
Future Work

Mechanical properties of human trabecular bone play an important role in age-related bone fragility and implant stability. Microfinite element (μFE) analysis allows computing the apparent elastic properties of trabecular bone for use in homogenized FE (hFE) analysis, but the results depend unfortunately on the type of applied boundary conditions (BCs). In this study, 167 human femoral trabecular cubic regions with a side length of 5.3 mm were extracted from three proximal femora and analyzed using μFE analysis to compare systematically their stiffness with kinematic uniform BCs (KUBCs) and periodicity-compatible mixed uniform BCs (PMUBCs). The obtained elastic constants were then used in the volume fraction and fabric-based orthotropic Zysset–Curnier model to identify their respective model parameters. As expected, PMUBCs lead to more compliant apparent elastic properties than KUBCs, especially in shear. The differences in stiffness decreased with bone volume fraction and mean intercept length (MIL). Unlike KUBCs, PMUBCs were sensitive to heterogeneity of the biopsies. The Zysset–Curnier model fitted the apparent elastic constants successfully in both cases with adjusted coefficients of determination (radj2) of 0.986 for KUBCs and 0.975 for PMUBCs. The proper use of these BCs for hFE analysis of whole bones will need to be investigated in future work.

scholarly journals Hallmarks of frailty and osteosarcopenia in prematurely aged PolgAD257A/D257A mice

2019 ◽  
Author(s):  
Ariane C. Scheuren ◽  
Gommaar D’Hulst ◽  
Gisela A. Kuhn ◽  
Evi Masschelein ◽  
Esther Wehrle ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Musculoskeletal System ◽  
Volume Fraction ◽  
Frailty Index ◽  
Bone Adaptation ◽  
Geriatric Syndrome ◽  
Bone Volume Fraction ◽  
Age Related ◽  
Caudal Vertebrae

AbstractBackgroundFrailty is a geriatric syndrome characterized by increased susceptibility to adverse health outcomes. One major determinant thereof is the gradual weakening of the musculoskeletal system and the associated osteosarcopenia. To improve our understanding of the underlying pathophysiology and, more importantly, to test potential interventions aimed at counteracting frailty suitable animal models are needed.MethodsTo evaluate the relevance of prematurely aged PolgA(D257A/D257A) mice as a model for frailty and osteosarcopenia, we quantified the clinical mouse frailty index in PolgA(D257A/D257A) and wild type littermates (PolgA(+/+), WT) with age and concertedly assessed the quantity and quality of bone and muscle tissue. Lastly, the anabolic responsiveness of skeletal muscle, muscle progenitors and bone was assessed.ResultsPolgA(D257A/D257A) accumulated health deficits at a higher rate compared to WT, resulting in a higher frailty index at 40 and 46 weeks of age (+166%, +278%, p<0.0001), respectively, with no differences between genotypes at 34 weeks. Concomitantly, PolgA(D257A/D257A) displayed progressive musculoskeletal deterioration such as reduced bone and muscle mass as well as impaired functionality thereof. In addition to lower muscle weights (-14%, p<0.05, -23%, p<0.0001) and fiber area (-20%, p<0.05, -22%, p<0.0001) at 40 and 46 weeks, respectively, PolgA(D257A/D257A) showed impairments in grip-strength and concentric muscle forces (p<0.05). PolgA(D257A/D257A) mutation altered the acute response to various anabolic stimuli in skeletal muscle and muscle progenitors. While PolgA(D257A/D257A) muscles were hypersensitive to eccentric contractions as well as leucine administration, shown by larger downstream signaling response of the mechanistic target of rapamycin complex 1 (mTORC1), myogenic progenitors cultured in vitro showed severe anabolic resistance to leucine and robust impairments in cell proliferation. Longitudinal micro-CT analysis of the 6th caudal vertebrae showed that PolgA(D257A/D257A) had lower bone morphometric parameters (e.g. bone volume fraction, trabecular and cortical thickness, p<0.05) as well as reduced remodeling activities (e.g. bone formation and resorption rate, p<0.05) compared to WT. When subjected to 4 weeks of cyclic loading, young but not aged PolgA(D257A/D257A) caudal vertebrae showed load-induced bone adaptation suggesting reduced mechanosensitivity with age.ConclusionsPolgA(D257A/D257A) mutation leads to hallmarks of age-related frailty and osteosarcopenia and provides a powerful model to better understand the relationship between frailty and the aging musculoskeletal system.

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.

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