scholarly journals Histomorphometric variance of haversian canal in cortical bone of Malaysian ethnic groups

2018 ◽  
Vol 1019 ◽  
pp. 012009
Author(s):  
Hadi Abdullah ◽  
Muhammad Mahadi Abdul Jamil ◽  
Faridah Mohd Nor
Keyword(s):  
Cortical Bone ◽  
Ethnic Groups ◽  
Haversian Canal

Mechanical Anisotropy of Individual Osteons in Bone Tissue at High Spatial Resolutions

2009 ◽  
Author(s):  
Davide Carnelli ◽  
Haimin Yao ◽  
Ming Dao ◽  
Pasquale Vena ◽  
Roberto Contro ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cortical Bone ◽  
Mechanical Anisotropy ◽  
Haversian Canal ◽  
Maximum Penetration ◽  
Fundamental Units ◽  
Anisotropy Of Mechanical Properties ◽  
Penetration Depths ◽  
Secondary Osteons ◽  
Mineralized Collagen

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.

scholarly journals Orientation and size-dependent mechanical modulation within individual secondary osteons in cortical bone tissue

2013 ◽  
Vol 10 (81) ◽  
pp. 20120953 ◽  
Author(s):  
Davide Carnelli ◽  
Pasquale Vena ◽  
Ming Dao ◽  
Christine Ortiz ◽  
Roberto Contro
Keyword(s):  
Mechanical Properties ◽  
Cortical Bone ◽  
Mechanical Behaviour ◽  
Long Bone ◽  
Periodic Pattern ◽  
Haversian Canal ◽  
Length Scale ◽  
Lamellar Bone ◽  
Mechanical Modulation ◽  
Secondary Osteons

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.

Transversely Isotropic Model of Osteonal Cortical Bone: Contribution of Haversian and Resorptive Porosity

1999 ◽  
Author(s):  
X. Neil Dong ◽  
Y. Young Huang ◽  
X. Edward Guo
Keyword(s):  
Cortical Bone ◽  
Transversely Isotropic ◽  
The Elderly ◽  
Haversian Canal ◽  
Isotropic Model ◽  
Elderly Men ◽  
Men And Women ◽  
Age Related ◽  
Osteoclastic Resorption ◽  
Old Men

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).

scholarly journals Evading the host response: Staphylococcus “hiding” in cortical bone canalicular system causes increased bacterial burden

Bone Research ◽  
2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Stephen D. Zoller ◽  
Vishal Hegde ◽  
Zachary D. C. Burke ◽  
Howard Y. Park ◽  
Chad R. Ishmael ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Haversian Canal ◽  
Limb Salvage Surgery ◽  
Allograft Bone ◽  
Bacterial Burden ◽  
Science Data ◽  
Translational Study ◽  
Study Results ◽  
Cortical Allograft ◽  
Extremity Reconstruction

AbstractExtremity reconstruction surgery is increasingly performed rather than amputation for patients with large-segment pathologic bone loss. Debate persists as to the optimal void filler for this “limb salvage” surgery, whether metal or allograft bone. Clinicians focus on optimizing important functional gains for patients, and the risk of devastating implant infection has been thought to be similar regardless of implant material. Recent insights into infection pathophysiology are challenging this equipoise, however, with both basic science data suggesting a novel mechanism of infection of Staphylococcus aureus (the most common infecting agent) into the host lacunar–canaliculi network, and also clinical data revealing a higher rate of infection of allograft over metal. The current translational study was therefore developed to bridge the gap between these insights in a longitudinal murine model of infection of allograft bone and metal. Real-time Staphylococci infection characteristics were quantified in cortical bone vs metal, and both microarchitecture of host implant and presence of host immune response were assessed. An orders-of-magnitude higher bacterial burden was established in cortical allograft bone over both metal and cancellous bone. The establishment of immune-evading microabscesses was confirmed in both cortical allograft haversian canal and the submicron canaliculi network in an additional model of mouse femur bone infection. These study results reveal a mechanism by which Staphylococci evasion of host immunity is possible, contributing to elevated risks of infection in cortical bone. The presence of this local infection reservoir imparts massive clinical implications that may alter the current paradigm of osteomyelitis and bulk allograft infection treatment.

Automated human cortical bone Haversian canal histomorphometric comparison system

2020 ◽  
pp. 25-67
Author(s):  
Hadi Abdullah ◽  
Muhammad Mahadi Abdul Jamil ◽  
Ijaz Khan ◽  
Mohd Helmy Bin Abd Wahab ◽  
Faridah Mohd Nor
Keyword(s):  
Cortical Bone ◽  
Haversian Canal ◽  
Comparison System ◽  
Human Cortical Bone

Bio-Morphing of Progressive Pathologies in Haversian Cortical Bone

2012 ◽  
Vol 79 (2) ◽  
Author(s):  
É. Budyn ◽  
J. Jonvaux ◽  
T. Hoc
Keyword(s):  
Cortical Bone ◽  
Volume Fraction ◽  
Morphological Changes ◽  
Local Strain ◽  
Haversian Canal ◽  
Canal Diameter ◽  
Microstructural Model ◽  
Growth Laws ◽  
Composite Microstructure ◽  
Haversian Canals

We present an evolutionary microstructural model to study the mechanical behavior of pathological Haversian cortical bone in the framework of linear elasticity. The Haversian cortical bone includes Haversian canals, osteons, cement lines, and interstitial bone. The composite microstructure is built using a Monte Carlo (MC) algorithm and initially displays a healthy morphology, which then evolves to mimic bone progressive aging, due to osteoporosis or low remodeling. The MC algorithm incorporates bone macroscopic morphological components such as porosity and osteonal volume fraction, microscopic parameters such as osteonal and Haversian canal diameter distributions, and also pathological growth laws characteristic of aging diseases. The local mechanical properties are measured by nanoindentation and microextensometry. The microstructures are discretised by a finite element 3D model to calculate the evolving representative volume element of aging bone, the macroscopic elastic bulk properties and microscopic strain and stress fields. The macroscopic anisotropy and local strain of aging bone are compared to those of healthy tissue in order to understand how morphological changes affect bone failure.

Finite Element and Experimental Investigation of Human Femur Cortical Bone Microdamage during Radial Fretting

2012 ◽  
Vol 486 ◽  
pp. 313-320
Author(s):  
Juan Liu ◽  
Huo Ming Shen ◽  
Yi Ren Yang ◽  
Zhen Bing Cai
Keyword(s):  
Cortical Bone ◽  
Load Condition ◽  
Fem Analysis ◽  
Surface Damage ◽  
Compact Bone ◽  
Bone Fragility ◽  
Haversian Canal ◽  
Modeling And Analysis ◽  
Human Femur ◽  
Bone Microdamage

Accumulation of microdamage can result in increased bone fragility and osteoporotic fracture in human bone.Microcracks in bone have been implicated in the development of stress fractures.The goal of this study was to investigate the human femur cortical bone microdamage during radial fretting and its stress and strain distribution. Modeling and analysis were taken for Haversian system using FEM soft. Analytical results indicated that stress concentration which occurred in the haversian canal and around circumferential lamellas and through the circumferential lamellas and the interstitial tissues could lead to microcrack initiation of multi-areas. In addition, microcrack could occur as a result of a rather large plastic area which crossed interstitial bone and connected adjacent osteon under high load condition. In the meantime, radial fretting behaviors of the fresh human axial femur compact bone were investigated under a flat-on-ball configuration in high accuracy hydraulic servo fretting experimental machine. The kinetics behaviors of the compact bone were revealed by the F-D curves. The surface damage was analyzed combined with the examinations by laser confocal scanning microscopy (LCSM) and scanning electron microscopy (SEM) . The morphologies showed that the microcracks were the primary damage form.The results showed that three typical types of cracks-radial microcrackannular microcrack and linking microcrack were observed. The test results and the FEM analysis results were of good consistency, and brought forth that most of microcracks run between the surrounding interstitial bone and the cement line.

‘Fever Phobia’ Persists in Many Ethnic Groups

2008 ◽  
Vol 42 (10) ◽  
pp. 42
Author(s):  
BETSY BATES
Keyword(s):  
Ethnic Groups ◽  
Fever Phobia

Suicidal Behavior in Four Ethnic Groups in The Hague, 2002–2004

Crisis ◽  
2009 ◽  
Vol 30 (2) ◽  
pp. 63-67 ◽  
Author(s):  
Irene Burger ◽  
Albert M. van Hemert ◽  
Willem J. Schudel ◽  
Barend J.C. Middelkoop
Keyword(s):  
Suicide Attempt ◽  
Ethnic Groups ◽  
Suicidal Behavior ◽  
Emergency Service ◽  
Attempted Suicide ◽  
Public Health Problem ◽  
Specific Rate ◽  
Completed Suicide ◽  
The Hague ◽  
Psychiatric Department

Background: Suicidal behavior is a severe public health problem. Aims: To determine the rates of attempted and completed suicide among ethnic groups in The Hague, The Netherlands (2002–2004). Methods: By analyzing data on attempted and completed suicide (from the psychiatric department of general medical hospitals; the psychiatric emergency service and the municipal coroners). Results: Turkish and Surinamese females aged 15–24 years were at highest risk for attempted suicide (age-specific rate 545 / 100,000 and 421 / 100,000 person-years, respectively). Both rates were significantly higher than in the same age group of Dutch females (246 / 100,000 person-years). Turkish (2%) and Surinamese (7%) had lower repeat suicide-attempt rates than did Dutch (16%) females aged 15–24. Significantly lower suicide-attempt rates were found for Surinamese than for Dutch females aged 35–54 years. Differences were not explained by socioeconomic living conditions. The ratio fatal/nonfatal events was 4.5 times higher in males than in females and varied across age, gender, and ethnicity strata. Completed suicide was rare among migrant females. No completed suicides were observed in the Turkish and Surinamese females aged 15–24 years. Conclusions: The study demonstrates a high risk of attempted suicide and a low risk of completed suicide among young Turkish and Surinamese females.

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