Topic
Osteon
About: Osteon is a research topic. Over the lifetime, 642 publications have been published within this topic receiving 20863 citations. The topic is also known as: Haversian System.
Papers published on a yearly basis
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Papers
TL;DR: It was concluded that there are measurable microscopic age changes in the cortex of the major long bones of the leg that can be used to estimate the age of an individual with known accuracy over the entire range from birth to 95 years.
Abstract: The microscopic age changes that occur in human cortical bone were measured by counting the number of osteones, osteon fragments and non-Haversian canals, and estimating the percentage of lamellar bone in four selected 100 power fields in the outer third of the cortex in ground sections from the mid-shaft of the femur, tibia and fibula. Age graphs were derived from 126 specimens covering the age range from birth through 95 years. The best correlation with age by regression analysis was found in the osteon fragment number in the fibula (ρ = 9.74). The use of the regression formula for this factor permits the age to be estimated within ± ten years of the actual age 95% of the time.
An alternative method utilizes a specially devised profile chart to estimate age from the age change graphs. When this method was checked on 56 additional specimens, 87.3% of the estimates were within ± five years of the actual age, and all estimates were within ± ten years.
It was concluded that there are measurable microscopic age changes in the cortex of the major long bones of the leg that can be used to estimate the age of an individual with known accuracy over the entire range from birth to 95 years. This method can be applied to fragmented and incomplete skeletons as well as eroded archeologic skeletons, since only the mid-shafts of leg bones are used.
482 citations
TL;DR: Fourier Transform Infrared Microspectroscopy (FTIRM) has been used to study the changes in mineral and matrix content and composition in replicate biopsies of non-osteoporotic human osteonal bone, suggesting their applicability for the analysis of mineral changes in disease.
Abstract: Fourier Transform Infrared Microspectroscopy (FTIRM) has been used to study the changes in mineral and matrix content and composition in replicate biopsies of nonosteoporotic human osteonal bone. Spectral maps in four orthogonal directions (in 10 microm steps) from the centers towards the peripheries of individual osteons were obtained from iliac crest biopsies of two necropsy cases. Mineral to matrix ratios, calculated from the ratio of integrated areas of the phosphate nu1,nu3 band at 900-1200 cm-1 to the amide I band at 1585-1725 cm-1, increased from the center to the periphery of the osteon. The total carbonate (based on the nu2 band at approximately 850-900 cm-1) to phosphate nu1,nu3 ratio decreased as the mineral to matrix ratio increased. Analysis of the nu2 CO32- band with a combination of second-derivative spectroscopy and curve fitting revealed a decrease in "labile" carbonate, a slight decrease in Type A and a slight increase in Type B carbonate from the center to the periphery of the osteon. Similar analysis of the components of the nu1,nu3 phosphate band with a combination of second-derivative spectroscopy and curve fitting revealed the presence of 11 major underlying moieties. These components were assigned by comparison with published frequencies for apatite and acid-phosphate containing calcium phosphates. The most consistent variations were alterations in the relative percent areas of bands at approximately 1020 and approximately 1030 cm-1, which had previously been assigned to nonstoichiometric and stoichiometric apatites, respectively. This ratio was used as an index of variation in crystal perfection throughout the osteon. This ratio decreased as the mineral to matrix ratio increased. The reproducibility of these parameters at multiple sites in multiple biopsies suggests their applicability for the analysis of mineral changes in disease.
395 citations
TL;DR: The comparison of compressive properties in single osteons and in macroscopic bone samples seems to support the view that the osteon is actually the mechanical unit of compact bone.
Abstract: The compressive strength of single human osteons has been investigated in specially prepared samples using a microtesting machine equipped with a microwave micrometer. The main conclusions which can be drawn from our results are: (1) In agreement with Gebhardt's theories the ultimate compressive strength is greatest for osteons having transversally oriented fiber bundles, lowest for osteons having longitudinally oriented fiber bundles, and intermediate for osteons whose fiber bundles change direction in successive lamellae through an angle of about 90°. (2) The modulus of elasticity is greatest in osteons with transversally oriented fiber bundles. (3) With all three types of osteon the stress-strain curves for fully calcified osteons are markedly different from those for osteons with low calcium content, the modulus of elasticity being much lower in osteons of the latter type. (4) Age seems to have no measurable influence on the compressive properties of osteons. (5) The comparison of compressive properties in single osteons and in macroscopic bone samples seems to support the view that the osteon is actually the mechanical unit of compact bone. (6) Fracture in osteon samples starts with microscopic fissures induced by shearing. (7) In every case these fissures form an angle of roughly 30°–35° with the axis of the osteon and do not appear to vary with the microscopic osteon structures. (8) Electron microscopy reveals distortion of bone crystals and breaking of collagen fibrils at the edges of the fissures.
393 citations
TL;DR: It is concluded that, although there must be other factors such as biochemical components and microdamage, osteon morphology has an important influence on fracture resistance of the cortical bone.
361 citations
TL;DR: The tensile stress‐strain curves show that, even at the level of single osteons, bone behaves like a complex material, which, according to Sedlin, can be represented by a Hooke body linked in series to a Kelvin body.
Abstract: The ultimate tensile strength and modulus of elasticity of individual osteons from human and ox compact bone were determined with a specially designed microwave extensimeter. The results were related to the degree of calcification and the orientation of collagen fiber-bundles in successive lamellae of the osteons. The following conclusions were made: (1) When osteon specimens are dried, their tensile strength and modulus of elasticity increase, while their percent elongation under tension falls. (2) In the osteon samples tested wet, the degree of calcification induces an increase in the modulus of elasticity with additional amounts of calcium salts. (3) The modulus of elasticity in tension of the organic matrix corresponds to that of collagen. (4) In the osteons having a marked longitudinal arrangement of bundles of fibers in successive lamellae, the ultimate tensile strength and modulus of elasticity seem greater and the percentage elongation under tension seems lower than in osteons whose bundles in successive lamellae change through an angle of about 90°. (5) The tensile properties of osteons seem independent of the age of the subject. (6) Human and ox osteons reveal the same tensile behavior. (7) The tensile stress-strain curves show that, even at the level of single osteons, bone behaves like a complex material, which, according to Sedlin, can be represented by a Hooke body linked in series to a Kelvin body.
351 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 5 |
| 2024 | 18 |
| 2023 | 27 |
| 2022 | 44 |
| 2021 | 26 |
| 2020 | 25 |