Transverse isotropic elastic properties of vertebral trabecular bone matrix measured using microindentation (effects of age, gender and vertebral level)

Bone ◽  
2009 ◽  
Vol 44 ◽  
pp. S392-S393
Author(s):  
U. Wolfram ◽  
H. Wilke ◽  
P.K. Zysset
Keyword(s):  
Trabecular Bone ◽  
Elastic Properties ◽  
Bone Matrix ◽  
Vertebral Level ◽  
Vertebral Trabecular Bone ◽  
Transverse Isotropic

TRANSVERSE ISOTROPIC ELASTIC PROPERTIES OF VERTEBRAL TRABECULAR BONE MATRIX MEASURED USING MICROINDENTATION UNDER DRY CONDITIONS (EFFECTS OF AGE, GENDER, AND VERTEBRAL LEVEL)

2010 ◽  
Vol 10 (01) ◽  
pp. 139-150 ◽  
Author(s):  
UWE WOLFRAM ◽  
HANS-JOACHIM WILKE ◽  
PHILIPPE K. ZYSSET
Keyword(s):  
Trabecular Bone ◽  
Elastic Properties ◽  
Cross Sections ◽  
Ex Vivo ◽  
Bone Matrix ◽  
Depth Sensing ◽  
Vertebral Level ◽  
Vertebral Trabecular Bone ◽  
Dry Conditions ◽  
Transverse Isotropic

The mechanical properties of bone extracellular matrix have become of increasing interest for the understanding of vertebral fracture risk. Depth-sensing indentation techniques allow the measurement of directional elastic properties of trabecular bone ex vivo with a high spatial resolution. Transverse isotropic elastic properties of vertebral trabecular bone obtained from two orthogonal directions were investigated using microindentation under dry conditions focusing on the influence of microanatomical location, age, gender, vertebral level, and anatomic direction on these properties. Biopsies were obtained from 104 human vertebrae (T1–L3) with a median age of 65 (21–94) years. Significantly, higher indentation moduli were found for indentations on axial than on transverse cross-sections of trabeculae (p < 0.01). Indentation moduli in the core were 1.05 to 1.12 times higher than in the periphery (p < 0.01). No difference in stiffness could be detected between males and females (p > 0.05) and different ages (p > 0.5). Vertebral level showed a weak correlation (p = 0.073, r2 ≈ 0.17). These results provide insights in the transverse isotropic properties of trabecular bone matrix related to age, gender, microanatomical location, and anatomic direction for a broad spectrum of human vertebrae.

Contributions of Trabecular Rods of Various Orientations in Determining the Elastic Properties of Human Vertebral Trabecular Bone

2007 ◽  
Author(s):  
Xiaowei S. Liu ◽  
X. Henry Zhang ◽  
Paul Sajda ◽  
Punam K. Saha ◽  
Felix W. Wehrli ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Trabecular Bone ◽  
Elastic Properties ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Micro Computed Tomography ◽  
Bone Volume Fraction ◽  
Human Trabecular Bone ◽  
Vertebral Trabecular Bone ◽  
Age Related

Osteoporosis is an age-related disease characterized by low bone mass and architectural deterioration. Other than bone volume fraction (BV/TV), microarchitecture of trabecular bone, such as trabecular type (rods or plates), connectivity, and orientation of the trabecular network is also believed to be important in governing the mechanical properties of trabecular bone. A recent study [1] showed that the microarchitecture alone affects elastic moduli of trabecular bone and, further, that trabecular plates make a far greater contribution than rods. In human vertebral trabecular bone, the roles of transverse vs. vertical rods in conferring mechanical properties of trabecular bone have been debated [2, 3]. It has been suggested that the role of transverse trabecular rod is critical in determining elastic modulus of vertebral trabecular bone. However, without explicit classifications of trabecular type, or orientation assessment at an individual trabecula level, it is not possible yet to test this hypothesis in human trabecular bone samples despite the development of three-dimensional (3D) micro computed tomography (μCT) and μCT based finite element (FE) models of human trabecular bone. With the newly developed technique of complete volumetric decomposition and individual trabecula based orientation analyses [4], now it is possible to quantitatively examine the contributions of trabecular rods of various orientations in the elastic properties of vertebral trabecular bone.

Quantitative computed tomography in measurement of vertebral trabecular bone mass

1988 ◽  
Vol 29 (6) ◽  
pp. 719-725 ◽  
Author(s):  
M. Nilsson ◽  
O. Johnell ◽  
K. Jonsson ◽  
I. Redlund-Johnell
Keyword(s):  
Computed Tomography ◽  
Bone Mass ◽  
Trabecular Bone ◽  
Quantitative Computed Tomography ◽  
Vertebral Trabecular Bone ◽  
Trabecular Bone Mass

scholarly journals Micromechanical analyses of vertebral trabecular bone based on individual trabeculae segmentation of plates and rods

2009 ◽  
Vol 42 (3) ◽  
pp. 249-256 ◽  
Author(s):  
X. Sherry Liu ◽  
Grant Bevill ◽  
Tony M. Keaveny ◽  
Paul Sajda ◽  
X. Edward Guo
Keyword(s):  
Trabecular Bone ◽  
Vertebral Trabecular Bone

MORPHOLOGY ANALYSIS OF VERTEBRAL TRABECULAR BONE UNDER DYNAMIC LOADING BY MULTISCALE THEORY

2012 ◽  
Vol 45 ◽  
pp. S533
Author(s):  
Naoki Takano ◽  
Khairul Salleh Basaruddin ◽  
Takuya Ishimoto ◽  
Takayoshi Nakano
Keyword(s):  
Trabecular Bone ◽  
Dynamic Loading ◽  
Vertebral Trabecular Bone ◽  
Morphology Analysis

scholarly journals Osteoblastic expansion induced by parathyroid hormone receptor signaling in murine osteocytes is not sufficient to increase hematopoietic stem cells

Blood ◽  
2012 ◽  
Vol 119 (11) ◽  
pp. 2489-2499 ◽  
Author(s):  
Laura M. Calvi ◽  
Olga Bromberg ◽  
Yumie Rhee ◽  
Jonathan M. Weber ◽  
Julianne N. P. Smith ◽  
...  
Keyword(s):  
Stem Cells ◽  
Parathyroid Hormone ◽  
Bone Mass ◽  
Hematopoietic Stem Cells ◽  
Trabecular Bone ◽  
Bone Matrix ◽  
Osteoblastic Cells ◽  
Hematopoietic Stem ◽  
Parathyroid Hormone Receptor ◽  
Mineralized Bone Matrix

Abstract Microenvironmental expansion of hematopoietic stem cells (HSCs) is induced by treatment with parathyroid hormone (PTH) or activation of the PTH receptor (PTH1R) in osteoblastic cells; however, the osteoblastic subset mediating this action of PTH is unknown. Osteocytes are terminally differentiated osteoblasts embedded in mineralized bone matrix but are connected with the BM. Activation of PTH1R in osteocytes increases osteoblastic number and bone mass. To establish whether osteocyte-mediated PTH1R signaling expands HSCs, we studied mice expressing a constitutively active PTH1R in osteocytes (TG mice). Osteoblasts, osteoclasts, and trabecular bone were increased in TG mice without changes in BM phenotypic HSCs or HSC function. TG mice had progressively increased trabecular bone but decreased HSC function. In severely affected TG mice, phenotypic HSCs were decreased in the BM but increased in the spleen. TG osteocytes had no increase in signals associated with microenvironmental HSC support, and the spindle-shaped osteoblastic cells that increased with PTH treatment were not present in TG bones. These findings demonstrate that activation of PTH1R signaling in osteocytes does not expand BM HSCs, which are instead decreased in TG mice. Therefore, osteocytes do not mediate the HSC expansion induced by PTH1R signaling. Further, osteoblastic expansion is not sufficient to increase HSCs.

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