scholarly journals Relating Bone Strain to Local Changes in Radius Microstructure Following 12 Months of Axial Forearm Loading in Women

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Megan E. Mancuso ◽  
Karen L. Troy
Keyword(s):  
Strain Gradient ◽  
Bone Structure ◽  
Quantitative Computed Tomography ◽  
Premenopausal Women ◽  
Bone Adaptation ◽  
Bone Strain ◽  
Exercise Interventions ◽  
Local Bone ◽  
Strain Magnitude ◽  
Very High

Abstract Work in animal models suggests that bone structure adapts to local bone strain, but this relationship has not been comprehensively studied in humans. Here, we quantified the influence of strain magnitude and gradient on bone adaptation in the forearm of premenopausal women performing compressive forearm loading (n = 11) and nonloading controls (n = 10). High resolution peripheral quantitative computed tomography (HRpQCT) scans of the distal radius acquired at baseline and 12 months of a randomized controlled experiment were used to identify local sites of bone formation and resorption. Bone strain was estimated using validated finite element (FE) models. Trabecular strain magnitude and gradient were higher near (within 200 μm) formation versus resorption (p < 0.05). Trabecular formation and resorption occurred preferentially near very high (>95th percentile) versus low (<5th percentile) strain magnitude and gradient elements, and very low strain elements were more likely to be near resorption than formation (p < 0.05). In the cortical compartment, strain gradient was higher near formation versus resorption (p < 0.05), and both formation and resorption occurred preferentially near very high versus low strain gradient elements (p < 0.05). At most, 54% of very high and low strain elements were near formation or resorption only, and similar trends were observed in the control and load groups. These findings suggest that strain, likely in combination with other physiological factors, influences adaptation under normal loads and in response to a novel loading intervention, and represents an important step toward defining exercise interventions to maximize bone strength.

scholarly journals Relating Bone Strain to Local Changes in Radius Microstructure Following 12 Months of Axial Forearm Loading in Women

2020 ◽  
Author(s):  
Megan E. Mancuso ◽  
Karen L. Troy
Keyword(s):  
Strain Gradient ◽  
Bone Structure ◽  
Quantitative Computed Tomography ◽  
Premenopausal Women ◽  
Bone Adaptation ◽  
Bone Strain ◽  
Exercise Interventions ◽  
Local Bone ◽  
Strain Magnitude ◽  
Very High

ABSTRACTWork in animal models suggest that bone structure adapts to local bone strain, but this relationship has not been comprehensively studied in humans. Here, we quantified the influence of strain magnitude and gradient on bone adaptation in the forearm of premenopausal women performing compressive forearm loading (n=11) and non-loading controls (n=10). High resolution peripheral quantitative computed tomography (HRpQCT) scans of the distal radius acquired at baseline and 12 months of a randomized controlled experiment were used to identify local sites of bone formation and resorption. Bone strain was estimated using validated finite element (FE) models. Trabecular strain magnitude and gradient were higher near (within 200 µm) formation versus resorption (p<0.05). Trabecular formation and resorption occurred preferentially near very high (>95th percentile) versus low (<5th percentile) strain magnitude and gradient elements, and very low strain elements were more likely to be near resorption than formation (p<0.05). In the cortical compartment, strain gradient was higher near formation versus resorption (p<0.05), and both formation and resorption occurred preferentially near very high versus low strain gradient elements (p<0.05). At most, 54% of very high and low strain elements were near formation or resorption only, and similar trends were observed in the control and load groups. These findings suggest that strain, likely in combination with other physiological factors, influences adaptation under normal loads and in response to a novel loading intervention, and represents an important step toward defining exercise interventions to maximize bone strength.

scholarly journals Bone strain magnitude is correlated with bone strain rate in tetrapods: implications for models of mechanotransduction

2015 ◽  
Vol 282 (1810) ◽  
pp. 20150321 ◽  
Author(s):  
B. R. Aiello ◽  
J. Iriarte-Diaz ◽  
R. W. Blob ◽  
M. T. Butcher ◽  
M. T. Carrano ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Strain Rate ◽  
Flow Rate ◽  
Structural Integrity ◽  
Tissue Level ◽  
Bone Adaptation ◽  
Bone Strain ◽  
Mechanical Stimuli ◽  
Fluid Flow Rate ◽  
Strain Magnitude

Hypotheses suggest that structural integrity of vertebrate bones is maintained by controlling bone strain magnitude via adaptive modelling in response to mechanical stimuli. Increased tissue-level strain magnitude and rate have both been identified as potent stimuli leading to increased bone formation. Mechanotransduction models hypothesize that osteocytes sense bone deformation by detecting fluid flow-induced drag in the bone's lacunar–canalicular porosity. This model suggests that the osteocyte's intracellular response depends on fluid-flow rate, a product of bone strain rate and gradient, but does not provide a mechanism for detection of strain magnitude. Such a mechanism is necessary for bone modelling to adapt to loads, because strain magnitude is an important determinant of skeletal fracture. Using strain gauge data from the limb bones of amphibians, reptiles, birds and mammals, we identified strong correlations between strain rate and magnitude across clades employing diverse locomotor styles and degrees of rhythmicity. The breadth of our sample suggests that this pattern is likely to be a common feature of tetrapod bone loading. Moreover, finding that bone strain magnitude is encoded in strain rate at the tissue level is consistent with the hypothesis that it might be encoded in fluid-flow rate at the cellular level, facilitating bone adaptation via mechanotransduction.

BONE ADAPTATION AND REGENERATION – NEW DEVELOPMENTS

2012 ◽  
Vol 17 ◽  
pp. 34-43 ◽  
Author(s):  
JENNEKE KLEIN-NULEND ◽  
ROMMEL GAUD BACABAC
Keyword(s):  
Bone Formation ◽  
Cell Signaling ◽  
Mechanical Loading ◽  
Bone Structure ◽  
Bone Cells ◽  
Mechanical Energy ◽  
Bone Adaptation ◽  
Mechanical Stimuli ◽  
Waste Products ◽  
Local Bone

Bone is a dynamic tissue that is constantly renewed and adapts to its local loading environment. Mechanical loading results in adaptive changes in bone size and shape that strengthen bone structure. The mechanisms for adaptation involve a multistep process called mechanotransduction, which is the ability of resident bone cells to perceive and translate mechanical energy into a cascade of structural and biochemical changes within the cells. The transduction of a mechanical signal to a biochemical response involves pathways within the cell membrane and cytoskeleton of the osteocytes, the professional mechansensor cells of bone. During the last decade the role of mechanosensitive osteocytes in bone metabolism and turnover, and the lacuno-canalicular porosity as the structure that mediates mechanosensing, is likely to reveal a new paradigm for understanding the bone formation response to mechanical loading, and the bone resorption response to disuse. Strain-derived fluid flow of interstitial fluid through the lacuno-canalicular porosity seems to mechanically activate the osteocytes, as well as ensures transport of cell signaling molecules, nutrients and waste products. Cell-cell signaling from the osteocyte sensor cells to the effector cells (osteoblasts or osteoclasts), and the effector cell response – either bone formation or resorption, allow an explanation of local bone gain and loss as well as remodeling in response to fatigue damage as processes supervised by mechanosensitive osteocytes. The osteogenic activity of cultured bone cells has been quantitatively correlated with varying stress stimulations highlighting the importance of the rate of loading. Theoretically a possible mechanism for the stress response by osteocytes is due to strain amplification at the pericellular matrix. Single cell studies on molecular responses of osteocytes provide insight on local architectural alignment in bone during remodeling. Alignment seems to occur as a result of the osteocytes sensing different canalicular flow patterns around cutting cone and reversal zone during loading, thus determining the bone's structure. Disturbances in architecture and permeability of the 3D porous network will affect transduction of mechanical loads to the mechanosensors. Uncovering the cellular and mechanical basis of the osteocyte's response to loading represents a significant challenge to our understanding of cellular mechanotransduction and bone remodeling. In view of the importance of mechanical stress for maintaining bone strength, mechanical stimuli have great potential for providing a therapeutic approach for bone (re)generation.

scholarly journals Influence of implant and screw type on local bone strain field: a preliminary study

2019 ◽  
Vol 22 (sup1) ◽  
pp. S434-S435
Author(s):  
J. Greenfield ◽  
K. Bruyère-Garnier ◽  
D. Mehler ◽  
P. Appelmann ◽  
S. Kuhn ◽  
...  
Keyword(s):  
Strain Field ◽  
Bone Strain ◽  
Local Bone ◽  
Preliminary Study

Compromised Volumetric Bone Density and Microarchitecture in men with Congenital Hypogonadotropic Hypogonadism

2021 ◽  
Author(s):  
Agnès Ostertag ◽  
Georgios E Papadakis ◽  
Corinne Collet ◽  
Severine Trabado ◽  
Luigi Maione ◽  
...  
Keyword(s):  
Bone Markers ◽  
Bone Structure ◽  
Hypogonadotropic Hypogonadism ◽  
Quantitative Computed Tomography ◽  
Hormonal Treatment ◽  
Mineral Density ◽  
Trabecular Microarchitecture ◽  
Trabecular Thickness ◽  
Congenital Hypogonadotropic Hypogonadism

Abstract Context Men with Congenital Hypogonadotropic Hypogonadism (CHH) and Kallmann syndrome (KS) have both low circulating testosterone and estradiol levels. Whether bone structure is affected remains unknown. Objective To characterize bone geometry, volumetric density and microarchitecture in CHH/KS. Design Cross-sectional study. Setting One tertiary academic French center. Patients and Controls 51 genotyped CHH/KS patients and 40 healthy volunteers were included. Ninety-eight percent of CHH/KS men had received testosterone and/or combined gonadotropins. Intervention(s) High-resolution Peripheral Quantitative Computed Tomography (HR-pQCT), Dual X-ray absorptiometry (DXA) and measurement of serum bone markers. Main Outcome Volumetric bone mineral density (vBMD), cortical and trabecular microarchitecture. Results CHH and controls did not differ for age, BMI, vitamin D and PTH levels. Despite long-term hormonal treatment (10.8 ± 6.8 years), DXA showed lower areal BMD in CHH/KS at lumbar spine, total hip, femoral neck and distal radius. Consistent with persistently higher serum bone markers, HR-pQCT revealed lower cortical and trabecular vBMD as well as cortical thickness at the tibia and the radius. CHH/KS men had altered trabecular microarchitecture with a predominant decrease of trabecular thickness. Moreover, CHH/KS men exhibited lower cortical bone area, whereas total and trabecular areas were higher only at the tibia. Earlier treatment onset (before the age of 19 years) conferred a significant advantage for trabecular bone volume/tissue volume and trabecular vBMD at the tibia. Conclusion Both vBMD and bone microarchitecture remain impaired in CHH/KS men despite long-term hormonal treatment. Treatment initiation during adolescence is associated with enhanced trabecular outcomes, highlighting the importance of early diagnosis.

scholarly journals Role of Dietary Intake and Serum 25(OH)D on the Effects of a Multicomponent Exercise Program on Bone Mass and Structure of Frail and Pre-Frail Older Adults

Nutrients ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3016
Author(s):  
Ana Moradell ◽  
David Navarrete-Villanueva ◽  
Ángel I. Fernández-García ◽  
Jorge Marín-Puyalto ◽  
Alejandro Gómez-Bruton ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Older Adults ◽  
Dietary Intake ◽  
Bone Mineral ◽  
Bone Structure ◽  
Quantitative Computed Tomography ◽  
Mineral Density ◽  
Frail Older Adults ◽  
Frail Elders ◽  
Tibia Length

The multicomponent training (MCT) effect on bone health in frail and pre-frail elders, which is influenced by dietary intake, is still unknown. The objective of this non-randomized intervention trial was to assess the effects of a 6-month MCT on bone structure in frail and pre-frail elders, and to analyse the influence of dietary intake and serum vitamin D (25(OH)D) in these changes. Thirty MCT (TRAIN) and sixteen controls (CON), frail and pre-frail completed the information required for this study. Peripheral quantitative computed tomography measurements were taken at 4% and 38% of the tibia length and dietary intake was registered. The 25(OH)D values were obtained from blood samples. Analyses of covariance (ANCOVA) for repeated measures showed significant decreases for CON in total bone mineral content at 38% of tibia length. One factor ANOVAs showed smaller decreases in bone mineral density and cortical thickness percentage of change in TRAIN compared to CON. Linear regression analyses were performed to study the influence of nutrients and 25(OH)D on bone changes. Alcohol showed a negative influence on fracture index changes, while polyunsaturated fatty acid and vitamin A showed a positive association with some bone variables. The 25(OH)D only affected positively the cortical bone mineral density. In conclusion, our MCT seems to slow down some of the bone detriments associated with ageing in frail and pre-frail older adults, with alcohol showing a negative effect on the bone and apparent limited effect of nutrients and serum 25(OH)D on training related changes.

scholarly journals Cortical bone density by quantitative computed tomography mirrors disorders of bone structure in bone biopsy of non-dialysis CKD patients

Bone Reports ◽  
2022 ◽  
pp. 101166
Author(s):  
Amandha L. Bittencourt ◽  
Maria Eugênia F. Canziani ◽  
Larissa D.B.R. Costa ◽  
Carlos E. Rochitte ◽  
Aluizio B. Carvalho
Keyword(s):  
Computed Tomography ◽  
Bone Density ◽  
Cortical Bone ◽  
Bone Structure ◽  
Bone Biopsy ◽  
Quantitative Computed Tomography ◽  
Cortical Bone Density

Bone Structure and the Dynamics of Bone Adaptation in Response to Accumulative Damage

1993 ◽  
Vol 86-87 ◽  
pp. 187-192
Author(s):  
Patrick J. Prendergast ◽  
H. Weinans ◽  
R. Huiskes ◽  
D. Taylor
Keyword(s):  
Bone Structure ◽  
Bone Adaptation

Mechanisms of bone remodeling during weight-bearing exercise

2006 ◽  
Vol 31 (6) ◽  
pp. 655-660 ◽  
Author(s):  
Ronald Zernicke ◽  
Christopher MacKay ◽  
Caeley Lorincz
Keyword(s):  
Mechanical Loading ◽  
Bone Structure ◽  
Weight Bearing ◽  
Bone Cell ◽  
Bone Adaptation ◽  
Bone Modeling ◽  
Extrinsic Factors ◽  
Paracrine Factors ◽  
Loading Effects ◽  
Exercise Induced

Exercise-induced mechanical loading can have potent effects on skeletal form and health. Both intrinsic and extrinsic factors contribute to bone structure and function. Mechanical simuli (e.g., strain magnitude, frequency, rate, and gradients, as well as fluid flow and shear stress) have potent influences on bone-cell cytoskeleton and associated signalling pathways. Although the immature skeleton may be more able to benefit from exercise, a skeletally mature population can also benefit from exercise programs aimed at increasing the functional loads to which the skeleton is exposed. The definitive explanation of mechanical-loading and (or) bone-cell mechanotransductive phenomena, however, remains elusive. Here, we briefly review the structural and anatomical foundation for bone adaptation, focusing on mechanical loading effects on bone, linked to the roles of integrins, cytoskeleton, membrane channels, and auto- and paracrine factors in bone modeling and remodeling.

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