scholarly journals DMP1 Ablation in the Rabbit Results in Mineralization Defects and Abnormalities in Haversian Canal/Osteon Microarchitecture

2019 ◽  
Vol 34 (6) ◽  
pp. 1115-1128 ◽  
Author(s):  
Tingjun Liu ◽  
Jun Wang ◽  
Xudong Xie ◽  
Ke Wang ◽  
Tingting Sui ◽  
...  
Keyword(s):  
Author(s):  
Davide Carnelli ◽  
Haimin Yao ◽  
Ming Dao ◽  
Pasquale Vena ◽  
Roberto Contro ◽  
...  

Secondary osteons, the fundamental units of cortical bone, consist of cylindrical lamellar composites composed of mineralized collagen fibrils. Due to its lamellar structure, a multiscale knowledge of the mechanical properties of cortical bone is required to understand the biomechanical function of the tissue. In this light, nanoindentation tests were performed along the axial and transverse directions following a radial path from the Haversian canal to the osteonal edges. Different length scales are explored by means of indentations at different maximum penetration depths. Indentation moduli and hardness data were then interpreted in the context of the known microstructure. Results suggest that secondary osteons hierarchical structure is responsible for an observed length scale effect, homogenization phenomena and anisotropy of mechanical properties.


1963 ◽  
Vol 41 (1) ◽  
pp. 19-22
Author(s):  
Elias D. Sedlin ◽  
Harold M. Frost

The authors' method depends on labelling in vivo the zone of demarcation of actively forming osteons by tetracycline antibiotics. The drugs, thus deposited in bone, are visualized by fluorescence microscopy. The label is a circular or elliptical ring whose diameter indicates the degree of completeness of the osteon at the time of drug administration. A histogram of the ring diameters therefore classifies labelled osteons as regards stage of completion at the time of drug administration. If an average formation time is assigned to osteons measured, conclusions relative to the rate of formation of the average osteon can be derived.In a histogram plotted from more than 900 labelled osteons in bones of three patients, most of the labels were concentrated in the inner half of the osteon. The authors conclude that osteon formation is initially rapid both in terms of cubic microns of bone formed in a unit time and in terms of decrease in diameter of the Haversian canal; it decreases with passage of time, and it ends with a critical minimum diameter of the Haversian canal. A 2-week cyclic variation in rate may be superimposed on the overall plot.


2018 ◽  
Vol 1019 ◽  
pp. 012009
Author(s):  
Hadi Abdullah ◽  
Muhammad Mahadi Abdul Jamil ◽  
Faridah Mohd Nor

2019 ◽  
Vol 19 (3) ◽  
pp. 823-840 ◽  
Author(s):  
Alexander F. van Tol ◽  
A. Roschger ◽  
F. Repp ◽  
J. Chen ◽  
P. Roschger ◽  
...  

AbstractA popular hypothesis explains the mechanosensitivity of bone due to osteocytes sensing the load-induced flow of interstitial fluid squeezed through the lacunocanalicular network (LCN). However, the way in which the intricate structure of the LCN influences fluid flow through the network is largely unexplored. We therefore aimed to quantify fluid flow through real LCNs from human osteons using a combination of experimental and computational techniques. Bone samples were stained with rhodamine to image the LCN with 3D confocal microscopy. Image analysis was then performed to convert image stacks into mathematical network structures, in order to estimate the intrinsic permeability of the osteons as well as the load-induced fluid flow using hydraulic circuit theory. Fluid flow was studied in both ordinary osteons with a rather homogeneous LCN as well as a frequent subtype of osteons—so-called osteon-in-osteons—which are characterized by a ring-like zone of low network connectivity between the inner and the outer parts of these osteons. We analyzed 8 ordinary osteons and 9 osteon-in-osteons from the femur midshaft of a 57-year-old woman without any known disease. While the intrinsic permeability was 2.7 times smaller in osteon-in-osteons compared to ordinary osteons, the load-induced fluid velocity was 2.3 times higher. This increased fluid velocity in osteon-in-osteons can be explained by the longer path length, needed to cross the osteon from the cement line to the Haversian canal, including more fluid-filled lacunae and canaliculi. This explanation was corroborated by the observation that a purely structural parameter—the mean path length to the Haversian canal—is an excellent predictor for the average fluid flow velocity. We conclude that osteon-in-osteons may be particularly significant contributors to the mechanosensitivity of cortical bone, due to the higher fluid flow in this type of osteons.


2007 ◽  
Vol 336-338 ◽  
pp. 1662-1665
Author(s):  
Guo Hua Xu ◽  
Xiao Jian Ye ◽  
Wen Yuan ◽  
Shu Cai ◽  
Jian Gang Shi ◽  
...  

In this paper, we study the effect of repairing the dog's femoral defects with the artificial bone integrating the nano-calcium phosphates/zirconia porous artificial bone scaffold with the autologous osteoblasts. We transplanted the artificial bone to the femoral defect of the dog, and at the same time, simple scaffold and the autologous cancellous bone were implanted as the control group. 3 months after the transplantation, the specimen was taken out with complete integration with the bone in these 3 groups and the bone defect got the complete bone union. The mechanics strength test showed that the group of the artificial bone was the strongest, followed by the cancellous bone group, and the simple material group was lower, but the strength was stronger than that before the transplantation. In the sixth month, the complete femoral defect repair was found in each group and the complete formation of the Haversian canal can be found on the histology examination. According to the mechanics strength test, there was no significant difference (P<0.05).


2013 ◽  
Vol 10 (81) ◽  
pp. 20120953 ◽  
Author(s):  
Davide Carnelli ◽  
Pasquale Vena ◽  
Ming Dao ◽  
Christine Ortiz ◽  
Roberto Contro

Anisotropy is one of the most peculiar aspects of cortical bone mechanics; however, its anisotropic mechanical behaviour should be treated only with strict relationship to the length scale of investigation. In this study, we focus on quantifying the orientation and size dependence of the spatial mechanical modulation in individual secondary osteons of bovine cortical bone using nanoindentation. Tests were performed on the same osteonal structure in the axial (along the long bone axis) and transverse (normal to the long bone axis) directions along arrays going radially out from the Haversian canal at four different maximum depths on three secondary osteons. Results clearly show a periodic pattern of stiffness with spatial distance across the osteon. The effect of length scale on lamellar bone anisotropy and the critical length at which homogenization of the mechanical properties occurs were determined. Further, a laminate-composite-based analytical model was applied to the stiffness trends obtained at the highest spatial resolution to evaluate the elastic constants for a sub-layer of mineralized collagen fibrils within an osteonal lamella on the basis of the spatial arrangement of the fibrils. The hierarchical arrangement of lamellar bone is found to be a major determinant for modulation of mechanical properties and anisotropic mechanical behaviour of the tissue.


2020 ◽  
Vol 44 (2) ◽  
pp. 15-24
Author(s):  
Saad H. Zebon

The present study was conducted to evaluate the effect of scaffold fabricated from Nano crab shell and Al-kharit (Papyrus Vaccine) for enhancing the healing of the experimentally induced bone defect in dogs. For this purpose, twenty healthy adult mongrel dogs were used in this study which divided randomly into two equal groups, under general anesthesia, 1 cm bone gap was created in the distal part of the tibia, that fixed by bone plate and screws. Nano crab shell scaffold was implanted. All experimental animals showed normal situation without any infection at the site of operation, while the radiography showed a periosteal and endosteal reaction. Moreover, the gaps were bridged faster in the treated group as compared with the control group. Treated animals showed new bone formation which represented by obvious lamellar bone, haversian canal and osteocyte cells in 90 days. In conclusion, the Nano crab shell scaffold gave better acceleration in the bone healing process, also this scaffolds may provide insight into the clinical repair of large bone defects


Author(s):  
C. D. Orupabo ◽  
L. E. Oghenemavwe ◽  
T. E. Diamond

Background. Age estimation is crucial in creating the biological profile of unknown skeletal remains and recently there is emphasis on the need to develop population specific forensic baseline data for easy identification of these remains. Objective. The aim of this study is to estimate age from the histomorphometric features of the bones of Nigerians. Methods. Fragments of non-pathologic bone samples were collected during orthopaedic procedures. Ground sections were prepared using Modified Frost’s manual method of bone preparation to determine the following histologic parameters; haversian canal diameter (HCD), primary and secondary osteons, number of osteon fragments and non-haversian canal as well as haversian canal area (HCA). 29 subjects aged 35 to 85 years old were used for the study. Bone fragments included samples from the femur, tibia, humerus, and the vertebrae. Data obtained were subjected to descriptive statistics, Pearson’s correlation, bivariate regression equation, Student t-test and analysis of variance (ANOVA). Results. The mean age for our population was 58.86 years old. ANOVA showed significant variation in the average HCD for the various regions: humerus=8.45±2.48, femur=7.09±4.06, tibia=8.70±2.52 and verte­brae=3.69±0.73. There was a strong inverse relationship between age and primary osteons. The total number of osteon fragments increased with age while total number of primary osteons and average HCD decreased with age. The HCA, though statistically insignificant, also decreased with age. Conclusion. Our findings show that three histomorphometric parameters showed significant correlation with age: osteon fragments (OS-f), primary osteons (OS-p) and HCD. The histomorphometric parameters were therefore relevant in age estimation.   Objective: The aim of this study is to estimate age from the histologic features of the bones of Nigerians.   Methods: Fragments of non-pathologic bone samples were collected during orthopaedic procedures. Ground sections were prepared using Modified Frost’s manual method of bone preparation to determine the following histologic parameters; haversian canal diameter (HCD), primary and secondary osteons, number of osteon fragments and non haversian canal as well as haversian canal area (HCA). 29 subjects aged 35 to 85 years were used for the study. Bone fragments included samples from the femur, tibia, humerus, and the vertebrae. Data obtained were subjected to descriptive statistics, Pearson’s correlation, bivariate regression equation, student t-test and Analysis of variance (ANOVA).   Results:  The mean age for our population was 58.86 years. ANOVA shows significant variation in the average HCD for the various regions: humerus=8.45±2.48, femur=7.09±4.06, tibia=8.70±2.52 and vertebrae=3.69±0.73. There is a strong inverse relationship between age and primary osteons. The total number of osteon fragments increased with age while total number of primary osteons and average HCD decreased with age. The HCA though statistically insignificant, also decreased with age.   Conclusion: Our findings show that three histomorphometric parameters showed significant correlation with age: osteon fragments (OS-f), primary osteons (OS-p) and HCD. The histomorphometric parameters are therefore relevant in age estimation.   Key words: Age estimation, Histomorphometric parameters, Nigerians, Forensics


1999 ◽  
Author(s):  
X. Neil Dong ◽  
Y. Young Huang ◽  
X. Edward Guo

Abstract Age related changes in porosity of cortical bone have been previously reported. The cortical porosity increases with age in both men and women, from 4.6% in men and 4% in women at age 40 to 10% and more at age 80 (Laval-Jeantet et al., 1983). The porosity is defined as the percentage of cortical bone occupied by vascular and resorption cavities. There are a few quantitative data regarding the influences of Haversian canal and resorption space on porosity. Age related increases in Haversian canal size and Haversian canal number contribute to the increasing porosity of cortical bone for the elderly men and women (Thompson, 1980; Nyssen-behets et al., 1997). The number of osteoclastic resorption space is also greater in the old men than in the young men (Nyssen-Behets et al., 1997).


2000 ◽  
Vol 123 (1) ◽  
pp. 66-70 ◽  
Author(s):  
A. F. T. Mak ◽  
J. D. Zhang

Bone is a very dynamic tissue capable of modifying its composition, microstructure, and overall geometry in response to the changing biomechanical needs. Streaming potential has been hypothesized as a mechanotransduction mechanism that may allow osteocytes to sense their biomechanical environment. A correct understanding of the mechanism for streaming potential will illuminate our understanding of bone remodeling, such as the remodeling associated with exercise hypertrophy, disuse atrophy, and the bone remodeling around implants. In the current research, a numerical model based on the finite element discretization is proposed to simulate the fluid flows through the complicated hierarchical flow system and to calculate the concomitant stress generated potential (SGP) as a result of applied mechanical loading. The lacunae–canaliculi and the matrix microporosity are modeled together as discrete one-dimensional flow channels superposed in a biphasic poroelastic matrix. The cusplike electric potential distribution surrounding the Haversian canal that was experimentally observed and reported in the literature earlier was successfully reproduced by the current numerical calculation.


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