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John G. Skedros - One of the best experts on this subject based on the ideXlab platform.
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Sealed Osteons in animals and humans: low prevalence and lack of relationship with age.
Journal of anatomy, 2018Co-Authors: John G. Skedros, Tanner R. Henrie, Madison S. Doutré, Roy D. BloebaumAbstract:Sealed Osteons are unusual variants of secondary Osteons that have received little attention, especially in non-human bones. Sealed Osteons are characterized by central canals that are plugged with bone tissue. As with other variants of secondary Osteons (e.g. drifting, dumbbell, multi-canal), understanding how and why sealed Osteons form can shed light on the mechanisms that regulate normal bone remodeling and how this process can be perturbed with aging and some diseases. In a recent microscopic evaluation of human tibiae obtained after traumatic amputations, 4-5% of the Osteons were sealed. It is suggested that this high prevalence reflects occasional localized microscopic ischemia from normal Osteonal remodeling; hence sealed Osteons are implicated in human skeletal fragility. Therefore, Osteon prevalence would be expected to correlate with the bone remodeling seen with aging; for example, showing positive relationships between sealed Osteons and the population density of typical secondary Osteons (OPD). We evaluated the prevalence of partially sealed (80-99% sealed) and fully sealed Osteons with respect to age and variations in OPD in 10 adult human femora (34-71 years) and in various non-human appendicular bones of mature animals that were not of advanced age, including deer calcanei, equine radii and equine third metacarpals. An additional sample of 10 bilateral human femora with unilateral non-cemented total hip replacements (F,+HR) and non-implanted contralateral femora (F,-HR) were evaluated (10 patients; 52-94 years). In non-human bones, sealed + partially sealed Osteons were rare (~0.1%) even when having relatively high OPD. When considering sealed + partially sealed Osteons in femora from patients without any HR, results showed that 1.6% of the Osteons were sealed or partially sealed, which was much lower than anticipated, but this is 10- to 20-fold more than in any of the non-human bones. Additionally, in all bones, sealed + partially sealed Osteons were significantly smaller than typical secondary Osteons (mean diameters: 125 vs. 272 μm; P
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utility of Osteon circularity for determining species and interpreting load history in primates and nonprimates
American Journal of Physical Anthropology, 2017Co-Authors: Kendra E. Keenan, Chad S Mears, John G. SkedrosAbstract:Objectives Histomorphological analyses of bones are used to estimate an individual's chronological age, interpret a bone's load history, and differentiate species. Among various histomorphological characteristics that can influence mechanical properties of cortical bone, secondary Osteon (Haversian system) population density and predominant collagen fiber orientation are particularly important. Cross-sectional shape characteristics of secondary Osteons (On.Cr = Osteon circularity, On.El = Osteon ellipticality) are considered helpful in these contexts, but more robust proof is needed. We sought to determine if variations in Osteon shape characteristics are sufficient for accurately differentiating species, load-complexity categories, and regional habitual strain-mode distributions (e.g., tension vs. compression regions). Materials and Methods Circularly polarized light images were obtained from 100-micron transverse sections from diaphyses of adult deer calcanei; sheep calcanei, radii, and tibiae; equine calcanei, radii, and third metacarpals (MC3s); chimpanzee femora; and human femora and fibulae. Osteon cross-sectional area (On.Ar), On.Cr, and On.El were quantified indiscriminately and in the contexts of load-complexity and regional strain-mode distributions. Results On.Cr and On.El, when examined independently in terms of all data, or mean (nested) data, for each bone, exceeded 80% accuracy in the inter-species comparisons only with respect to distinguishing humans from nonhumans. Correct classification among the nonhuman species was <70%. When On.Cr and On.El were coupled together and with On.Ar in discriminant function analyses (nested and unnested data) there were high misclassifications in all but human vs. nonhuman comparisons. Discussion Frequent misclassifications in nonhuman comparisons might reflect influences of habitual load complexity and/or strain-mode distributions, or other factors not accounted for by these two considerations.
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Scaling of Haversian canal surface area to secondary Osteon bone volume in ribs and limb bones.
American journal of physical anthropology, 2013Co-Authors: John G. Skedros, Alex N. Knight, Gunnar C. Clark, Christian M. Crowder, Victoria M. Dominguez, Shijing Qiu, Dawn M. Mulhern, Seth W. Donahue, Björn Busse, Brannon I HulseyAbstract:Studies of secondary Osteons in ribs have provided a great deal of what is known about remodeling dynamics. Compared with limb bones, ribs are metabolically more active and sensitive to hormonal changes, and receive frequent low-strain loading. Optimization for calcium exchange in rib Osteons might be achieved without incurring a significant reduction in safety factor by disproportionally increasing central canal size with increased Osteon size (positive allometry). By contrast, greater mechanical loads on limb bones might favor reducing deleterious consequences of intracortical porosity by decreasing Osteon canal size with increased Osteon size (negative allometry). Evidence of this metabolic/mechanical dichotomy between ribs and limb bones was sought by examining relationships between Haversian canal surface area (BS, Osteon Haversian canal perimeter, HC.Pm) and bone volume (BV, Osteonal wall area, B.Ar) in a broad size range of mature (quiescent) Osteons from adult human limb bones and ribs (modern and medieval) and various adult and subadult non-human limb bones and ribs. Reduced major axis (RMA) and least-squares (LS) regressions of HC.Pm/B.Ar data show that rib and limb Osteons cannot be distinguished by dimensional allometry of these parameters. Although four of the five rib groups showed positive allometry in terms of the RMA slopes, nearly 50% of the adult limb bone groups also showed positive allometry when negative allometry was expected. Consequently, our results fail to provide clear evidence that BS/BV scaling reflects a rib versus limb bone dichotomy whereby calcium exchange might be preferentially enhanced in rib Osteons. Am J Phys Anthropol 151:230–244, 2013. © 2013 Wiley Periodicals, Inc.
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Scaling of Haversian canal surface area to secondary Osteon bone volume in ribs and limb bones.
American journal of physical anthropology, 2013Co-Authors: John G. Skedros, Alex N. Knight, Gunnar C. Clark, Christian M. Crowder, Victoria M. Dominguez, Shijing Qiu, Dawn M. Mulhern, Seth W. Donahue, Björn Busse, Brannon I HulseyAbstract:Studies of secondary Osteons in ribs have provided a great deal of what is known about remodeling dynamics. Compared with limb bones, ribs are metabolically more active and sensitive to hormonal changes, and receive frequent low-strain loading. Optimization for calcium exchange in rib Osteons might be achieved without incurring a significant reduction in safety factor by disproportionally increasing central canal size with increased Osteon size (positive allometry). By contrast, greater mechanical loads on limb bones might favor reducing deleterious consequences of intracortical porosity by decreasing Osteon canal size with increased Osteon size (negative allometry). Evidence of this metabolic/mechanical dichotomy between ribs and limb bones was sought by examining relationships between Haversian canal surface area (BS, Osteon Haversian canal perimeter, HC.Pm) and bone volume (BV, Osteonal wall area, B.Ar) in a broad size range of mature (quiescent) Osteons from adult human limb bones and ribs (modern and medieval) and various adult and subadult non-human limb bones and ribs. Reduced major axis (RMA) and least-squares (LS) regressions of HC.Pm/B.Ar data show that rib and limb Osteons cannot be distinguished by dimensional allometry of these parameters. Although four of the five rib groups showed positive allometry in terms of the RMA slopes, nearly 50% of the adult limb bone groups also showed positive allometry when negative allometry was expected. Consequently, our results fail to provide clear evidence that BS/BV scaling reflects a rib versus limb bone dichotomy whereby calcium exchange might be preferentially enhanced in rib Osteons.
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secondary Osteon size and collagen lamellar organization Osteon morphotypes are not coupled but potentially adapt independently for local strain mode or magnitude
Journal of Structural Biology, 2013Co-Authors: John G. Skedros, Kendra E. Keenan, Tyler J. Williams, Casey J. KiserAbstract:In bone, matrix slippage that occurs at cement lines of secondary Osteons during loading is an important toughening mechanism. Toughness can also be enhanced by modifications in Osteon cross-sectional size (diameter) for specific load environments; for example, smaller Osteons in more highly strained "compression" regions vs. larger Osteons in less strained "tension" regions. Additional Osteon characteristics that enhance toughness are distinctive variations in collagen/lamellar organization (i.e., "Osteon morphotypes"). Interactions might exist between Osteon diameter and morphotype that represent adaptations for resisting deleterious shear stresses that occur at the cement line. This may be why Osteons often have a peripheral ring (or "hoop") of highly oblique/transverse collagen. We hypothesized that well developed/distinct "hoops" are compensatory adaptations in cases where increased Osteon diameter is mechanically advantageous (e.g., larger Osteons in "tension" regions would have well developed/distinct "hoops" in order to resist deleterious consequences of co-existing localized shear stresses). We tested this hypothesis by determining if there are correlations between Osteon diameters and strongly hooped morphotypes in "tension", "compression", and "neutral axis" regions of femora (chimpanzees, humans), radii (horse, sheep) and calcanei (horse, deer). The results reject the hypothesis-larger Osteons are not associated with well developed/distinct "hoops", even in "tension regions" where the effect was expected to be obvious. Although Osteon diameter and morphotype are not coupled, Osteon diameters seem to be associated with increased strain magnitudes in some cases, but this is inconsistent. By contrast, Osteon morphotypes are more strongly correlated with the distribution of tension and compression.
Brannon I Hulsey - One of the best experts on this subject based on the ideXlab platform.
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Scaling of Haversian canal surface area to secondary Osteon bone volume in ribs and limb bones.
American journal of physical anthropology, 2013Co-Authors: John G. Skedros, Alex N. Knight, Gunnar C. Clark, Christian M. Crowder, Victoria M. Dominguez, Shijing Qiu, Dawn M. Mulhern, Seth W. Donahue, Björn Busse, Brannon I HulseyAbstract:Studies of secondary Osteons in ribs have provided a great deal of what is known about remodeling dynamics. Compared with limb bones, ribs are metabolically more active and sensitive to hormonal changes, and receive frequent low-strain loading. Optimization for calcium exchange in rib Osteons might be achieved without incurring a significant reduction in safety factor by disproportionally increasing central canal size with increased Osteon size (positive allometry). By contrast, greater mechanical loads on limb bones might favor reducing deleterious consequences of intracortical porosity by decreasing Osteon canal size with increased Osteon size (negative allometry). Evidence of this metabolic/mechanical dichotomy between ribs and limb bones was sought by examining relationships between Haversian canal surface area (BS, Osteon Haversian canal perimeter, HC.Pm) and bone volume (BV, Osteonal wall area, B.Ar) in a broad size range of mature (quiescent) Osteons from adult human limb bones and ribs (modern and medieval) and various adult and subadult non-human limb bones and ribs. Reduced major axis (RMA) and least-squares (LS) regressions of HC.Pm/B.Ar data show that rib and limb Osteons cannot be distinguished by dimensional allometry of these parameters. Although four of the five rib groups showed positive allometry in terms of the RMA slopes, nearly 50% of the adult limb bone groups also showed positive allometry when negative allometry was expected. Consequently, our results fail to provide clear evidence that BS/BV scaling reflects a rib versus limb bone dichotomy whereby calcium exchange might be preferentially enhanced in rib Osteons. Am J Phys Anthropol 151:230–244, 2013. © 2013 Wiley Periodicals, Inc.
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Scaling of Haversian canal surface area to secondary Osteon bone volume in ribs and limb bones.
American journal of physical anthropology, 2013Co-Authors: John G. Skedros, Alex N. Knight, Gunnar C. Clark, Christian M. Crowder, Victoria M. Dominguez, Shijing Qiu, Dawn M. Mulhern, Seth W. Donahue, Björn Busse, Brannon I HulseyAbstract:Studies of secondary Osteons in ribs have provided a great deal of what is known about remodeling dynamics. Compared with limb bones, ribs are metabolically more active and sensitive to hormonal changes, and receive frequent low-strain loading. Optimization for calcium exchange in rib Osteons might be achieved without incurring a significant reduction in safety factor by disproportionally increasing central canal size with increased Osteon size (positive allometry). By contrast, greater mechanical loads on limb bones might favor reducing deleterious consequences of intracortical porosity by decreasing Osteon canal size with increased Osteon size (negative allometry). Evidence of this metabolic/mechanical dichotomy between ribs and limb bones was sought by examining relationships between Haversian canal surface area (BS, Osteon Haversian canal perimeter, HC.Pm) and bone volume (BV, Osteonal wall area, B.Ar) in a broad size range of mature (quiescent) Osteons from adult human limb bones and ribs (modern and medieval) and various adult and subadult non-human limb bones and ribs. Reduced major axis (RMA) and least-squares (LS) regressions of HC.Pm/B.Ar data show that rib and limb Osteons cannot be distinguished by dimensional allometry of these parameters. Although four of the five rib groups showed positive allometry in terms of the RMA slopes, nearly 50% of the adult limb bone groups also showed positive allometry when negative allometry was expected. Consequently, our results fail to provide clear evidence that BS/BV scaling reflects a rib versus limb bone dichotomy whereby calcium exchange might be preferentially enhanced in rib Osteons.
Victoria M. Dominguez - One of the best experts on this subject based on the ideXlab platform.
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Examination of Factors Potentially Influencing Osteon Size in the Human Rib
Anatomical record (Hoboken N.J. : 2007), 2016Co-Authors: Victoria M. Dominguez, Amanda M. AgnewAbstract:Previous research demonstrates that the size of secondary Osteons varies considerably between individuals, though what factors act in the delineation of Osteon size remain uncertain. This study explores the influence of age, sex, percent cortical area (%Ct.Ar), percent cortical porosity (%Po.Ar), and loading environment on Osteon area (On.Ar) in human ribs. The sample consisted of midshaft 6(th) ribs from 80 individuals, 6-94 years of age. T-tests demonstrated no significant differences in On.Ar between the sexes (P=0.383). Age showed a significant correlation with both %Ct.Ar and %Po.Ar, so a hierarchical regression model was used to control for the effects of age on the other variables. Results indicate that age is the most significant factor of those tested in this study (P=0.004), with %Ct.Ar playing a much smaller but still significant role (P=0.014), while %Po.Ar had no significant influence on On.Ar (P=0.443). Age demonstrates an inverse relationship with On.Ar, while %Ct.Ar has a direct relationship with On.Ar. Significant differences in On.Ar between the pleural and cutaneous cortices are attributed to variation in %Ct.Ar of each cortex. Therefore, age and %Ct.Ar account for the majority of Osteon size variability in this study, although it is likely genetics play an important role as well. Understanding the biological mechanisms that act in remodeling and determine Osteon size is essential for accurately addressing and interpreting histological findings, work that is invaluable in its implications for bone biology.
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Scaling of Haversian canal surface area to secondary Osteon bone volume in ribs and limb bones.
American journal of physical anthropology, 2013Co-Authors: John G. Skedros, Alex N. Knight, Gunnar C. Clark, Christian M. Crowder, Victoria M. Dominguez, Shijing Qiu, Dawn M. Mulhern, Seth W. Donahue, Björn Busse, Brannon I HulseyAbstract:Studies of secondary Osteons in ribs have provided a great deal of what is known about remodeling dynamics. Compared with limb bones, ribs are metabolically more active and sensitive to hormonal changes, and receive frequent low-strain loading. Optimization for calcium exchange in rib Osteons might be achieved without incurring a significant reduction in safety factor by disproportionally increasing central canal size with increased Osteon size (positive allometry). By contrast, greater mechanical loads on limb bones might favor reducing deleterious consequences of intracortical porosity by decreasing Osteon canal size with increased Osteon size (negative allometry). Evidence of this metabolic/mechanical dichotomy between ribs and limb bones was sought by examining relationships between Haversian canal surface area (BS, Osteon Haversian canal perimeter, HC.Pm) and bone volume (BV, Osteonal wall area, B.Ar) in a broad size range of mature (quiescent) Osteons from adult human limb bones and ribs (modern and medieval) and various adult and subadult non-human limb bones and ribs. Reduced major axis (RMA) and least-squares (LS) regressions of HC.Pm/B.Ar data show that rib and limb Osteons cannot be distinguished by dimensional allometry of these parameters. Although four of the five rib groups showed positive allometry in terms of the RMA slopes, nearly 50% of the adult limb bone groups also showed positive allometry when negative allometry was expected. Consequently, our results fail to provide clear evidence that BS/BV scaling reflects a rib versus limb bone dichotomy whereby calcium exchange might be preferentially enhanced in rib Osteons. Am J Phys Anthropol 151:230–244, 2013. © 2013 Wiley Periodicals, Inc.
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Scaling of Haversian canal surface area to secondary Osteon bone volume in ribs and limb bones.
American journal of physical anthropology, 2013Co-Authors: John G. Skedros, Alex N. Knight, Gunnar C. Clark, Christian M. Crowder, Victoria M. Dominguez, Shijing Qiu, Dawn M. Mulhern, Seth W. Donahue, Björn Busse, Brannon I HulseyAbstract:Studies of secondary Osteons in ribs have provided a great deal of what is known about remodeling dynamics. Compared with limb bones, ribs are metabolically more active and sensitive to hormonal changes, and receive frequent low-strain loading. Optimization for calcium exchange in rib Osteons might be achieved without incurring a significant reduction in safety factor by disproportionally increasing central canal size with increased Osteon size (positive allometry). By contrast, greater mechanical loads on limb bones might favor reducing deleterious consequences of intracortical porosity by decreasing Osteon canal size with increased Osteon size (negative allometry). Evidence of this metabolic/mechanical dichotomy between ribs and limb bones was sought by examining relationships between Haversian canal surface area (BS, Osteon Haversian canal perimeter, HC.Pm) and bone volume (BV, Osteonal wall area, B.Ar) in a broad size range of mature (quiescent) Osteons from adult human limb bones and ribs (modern and medieval) and various adult and subadult non-human limb bones and ribs. Reduced major axis (RMA) and least-squares (LS) regressions of HC.Pm/B.Ar data show that rib and limb Osteons cannot be distinguished by dimensional allometry of these parameters. Although four of the five rib groups showed positive allometry in terms of the RMA slopes, nearly 50% of the adult limb bone groups also showed positive allometry when negative allometry was expected. Consequently, our results fail to provide clear evidence that BS/BV scaling reflects a rib versus limb bone dichotomy whereby calcium exchange might be preferentially enhanced in rib Osteons.
Gunnar C. Clark - One of the best experts on this subject based on the ideXlab platform.
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Scaling of Haversian canal surface area to secondary Osteon bone volume in ribs and limb bones.
American journal of physical anthropology, 2013Co-Authors: John G. Skedros, Alex N. Knight, Gunnar C. Clark, Christian M. Crowder, Victoria M. Dominguez, Shijing Qiu, Dawn M. Mulhern, Seth W. Donahue, Björn Busse, Brannon I HulseyAbstract:Studies of secondary Osteons in ribs have provided a great deal of what is known about remodeling dynamics. Compared with limb bones, ribs are metabolically more active and sensitive to hormonal changes, and receive frequent low-strain loading. Optimization for calcium exchange in rib Osteons might be achieved without incurring a significant reduction in safety factor by disproportionally increasing central canal size with increased Osteon size (positive allometry). By contrast, greater mechanical loads on limb bones might favor reducing deleterious consequences of intracortical porosity by decreasing Osteon canal size with increased Osteon size (negative allometry). Evidence of this metabolic/mechanical dichotomy between ribs and limb bones was sought by examining relationships between Haversian canal surface area (BS, Osteon Haversian canal perimeter, HC.Pm) and bone volume (BV, Osteonal wall area, B.Ar) in a broad size range of mature (quiescent) Osteons from adult human limb bones and ribs (modern and medieval) and various adult and subadult non-human limb bones and ribs. Reduced major axis (RMA) and least-squares (LS) regressions of HC.Pm/B.Ar data show that rib and limb Osteons cannot be distinguished by dimensional allometry of these parameters. Although four of the five rib groups showed positive allometry in terms of the RMA slopes, nearly 50% of the adult limb bone groups also showed positive allometry when negative allometry was expected. Consequently, our results fail to provide clear evidence that BS/BV scaling reflects a rib versus limb bone dichotomy whereby calcium exchange might be preferentially enhanced in rib Osteons. Am J Phys Anthropol 151:230–244, 2013. © 2013 Wiley Periodicals, Inc.
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Scaling of Haversian canal surface area to secondary Osteon bone volume in ribs and limb bones.
American journal of physical anthropology, 2013Co-Authors: John G. Skedros, Alex N. Knight, Gunnar C. Clark, Christian M. Crowder, Victoria M. Dominguez, Shijing Qiu, Dawn M. Mulhern, Seth W. Donahue, Björn Busse, Brannon I HulseyAbstract:Studies of secondary Osteons in ribs have provided a great deal of what is known about remodeling dynamics. Compared with limb bones, ribs are metabolically more active and sensitive to hormonal changes, and receive frequent low-strain loading. Optimization for calcium exchange in rib Osteons might be achieved without incurring a significant reduction in safety factor by disproportionally increasing central canal size with increased Osteon size (positive allometry). By contrast, greater mechanical loads on limb bones might favor reducing deleterious consequences of intracortical porosity by decreasing Osteon canal size with increased Osteon size (negative allometry). Evidence of this metabolic/mechanical dichotomy between ribs and limb bones was sought by examining relationships between Haversian canal surface area (BS, Osteon Haversian canal perimeter, HC.Pm) and bone volume (BV, Osteonal wall area, B.Ar) in a broad size range of mature (quiescent) Osteons from adult human limb bones and ribs (modern and medieval) and various adult and subadult non-human limb bones and ribs. Reduced major axis (RMA) and least-squares (LS) regressions of HC.Pm/B.Ar data show that rib and limb Osteons cannot be distinguished by dimensional allometry of these parameters. Although four of the five rib groups showed positive allometry in terms of the RMA slopes, nearly 50% of the adult limb bone groups also showed positive allometry when negative allometry was expected. Consequently, our results fail to provide clear evidence that BS/BV scaling reflects a rib versus limb bone dichotomy whereby calcium exchange might be preferentially enhanced in rib Osteons.
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Analysis of the Effect of Osteon Diameter on the Potential Relationship of Osteocyte Lacuna Density and Osteon Wall Thickness
Anatomical record (Hoboken N.J. : 2007), 2011Co-Authors: John G. Skedros, Gunnar C. Clark, Scott M. Sorenson, Kevin W. Taylor, Shijing QiuAbstract:An important hypothesis is that the degree of infilling of secondary Osteons (Haversian systems) is controlled by the inhibitory effect of osteocytes on osteoblasts, which might be mediated by sclerostin (a glycoprotein produced by osteocytes). Consequently, this inhibition could be proportional to cell number: relatively greater repression is exerted by progressively greater osteocyte density (increased osteocytes correlate with thinner Osteon walls). This hypothesis has been examined, but only weakly supported, in sheep ulnae. We looked for this inverse relationship between Osteon wall thickness (On.W.Th) and osteocyte lacuna density (Ot.Lc.N/B.Ar) in small and large Osteons in human ribs, calcanei of sheep, deer, elk, and horses, and radii and third metacarpals of horses. Analyses involved: (1) all Osteons, (2) smaller Osteons, either ≤150 μm diameter or less than or equal to the mean diameter, and (3) larger Osteons (>mean diameter). Significant, but weak, correlations between Ot.Lc.N/B.Ar and On.W.Th/On.Dm (On.Dm = Osteon diameter) were found when considering all Osteons in limb bones (r values -0.16 to -0.40, P < 0.01; resembling previous results in sheep ulnae: r = -0.39, P < 0.0001). In larger Osteons, these relationships were either not significant (five/seven bone types) or very weak (two/seven bone types). In ribs, a negative relationship was only found in smaller Osteons (r = -0.228, P < 0.01); this inverse relationship in smaller Osteons did not occur in elk calcanei. These results do not provide clear or consistent support for the hypothesized inverse relationship. However, correlation analyses may fail to detect osteocyte-based repression of infilling if the signal is spatially nonuniform (e.g., increased near the central canal).
Christian M. Crowder - One of the best experts on this subject based on the ideXlab platform.
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Scaling of Haversian canal surface area to secondary Osteon bone volume in ribs and limb bones.
American journal of physical anthropology, 2013Co-Authors: John G. Skedros, Alex N. Knight, Gunnar C. Clark, Christian M. Crowder, Victoria M. Dominguez, Shijing Qiu, Dawn M. Mulhern, Seth W. Donahue, Björn Busse, Brannon I HulseyAbstract:Studies of secondary Osteons in ribs have provided a great deal of what is known about remodeling dynamics. Compared with limb bones, ribs are metabolically more active and sensitive to hormonal changes, and receive frequent low-strain loading. Optimization for calcium exchange in rib Osteons might be achieved without incurring a significant reduction in safety factor by disproportionally increasing central canal size with increased Osteon size (positive allometry). By contrast, greater mechanical loads on limb bones might favor reducing deleterious consequences of intracortical porosity by decreasing Osteon canal size with increased Osteon size (negative allometry). Evidence of this metabolic/mechanical dichotomy between ribs and limb bones was sought by examining relationships between Haversian canal surface area (BS, Osteon Haversian canal perimeter, HC.Pm) and bone volume (BV, Osteonal wall area, B.Ar) in a broad size range of mature (quiescent) Osteons from adult human limb bones and ribs (modern and medieval) and various adult and subadult non-human limb bones and ribs. Reduced major axis (RMA) and least-squares (LS) regressions of HC.Pm/B.Ar data show that rib and limb Osteons cannot be distinguished by dimensional allometry of these parameters. Although four of the five rib groups showed positive allometry in terms of the RMA slopes, nearly 50% of the adult limb bone groups also showed positive allometry when negative allometry was expected. Consequently, our results fail to provide clear evidence that BS/BV scaling reflects a rib versus limb bone dichotomy whereby calcium exchange might be preferentially enhanced in rib Osteons. Am J Phys Anthropol 151:230–244, 2013. © 2013 Wiley Periodicals, Inc.
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Scaling of Haversian canal surface area to secondary Osteon bone volume in ribs and limb bones.
American journal of physical anthropology, 2013Co-Authors: John G. Skedros, Alex N. Knight, Gunnar C. Clark, Christian M. Crowder, Victoria M. Dominguez, Shijing Qiu, Dawn M. Mulhern, Seth W. Donahue, Björn Busse, Brannon I HulseyAbstract:Studies of secondary Osteons in ribs have provided a great deal of what is known about remodeling dynamics. Compared with limb bones, ribs are metabolically more active and sensitive to hormonal changes, and receive frequent low-strain loading. Optimization for calcium exchange in rib Osteons might be achieved without incurring a significant reduction in safety factor by disproportionally increasing central canal size with increased Osteon size (positive allometry). By contrast, greater mechanical loads on limb bones might favor reducing deleterious consequences of intracortical porosity by decreasing Osteon canal size with increased Osteon size (negative allometry). Evidence of this metabolic/mechanical dichotomy between ribs and limb bones was sought by examining relationships between Haversian canal surface area (BS, Osteon Haversian canal perimeter, HC.Pm) and bone volume (BV, Osteonal wall area, B.Ar) in a broad size range of mature (quiescent) Osteons from adult human limb bones and ribs (modern and medieval) and various adult and subadult non-human limb bones and ribs. Reduced major axis (RMA) and least-squares (LS) regressions of HC.Pm/B.Ar data show that rib and limb Osteons cannot be distinguished by dimensional allometry of these parameters. Although four of the five rib groups showed positive allometry in terms of the RMA slopes, nearly 50% of the adult limb bone groups also showed positive allometry when negative allometry was expected. Consequently, our results fail to provide clear evidence that BS/BV scaling reflects a rib versus limb bone dichotomy whereby calcium exchange might be preferentially enhanced in rib Osteons.
