Three-dimensional reconstruction of Haversian systems in human cortical bone using synchrotron radiation-based micro-CT: morphology and quantification of branching and transverse connections across age (original) (raw)
Related papers
Three-Dimensional Reconstruction of Haversian Systems in Ovine Compact Bone
European Journal of Morphology, 2002
This study uses synchrotron radiation-based micro-computed tomography (CT) scans to reconstruct threedimensional networks of Haversian systems in human cortical bone in order to observe and analyse interconnectivity of Haversian systems and the development of total Haversian networks across different ages. A better knowledge of how Haversian systems interact with each other is essential to improve understanding of remodeling mechanisms and bone maintenance; however, previous methodological approaches (e.g. serial sections) did not reveal enough detail to follow the specific morphology of Haversian branching, for example. Accordingly, the aim of the present study was to identify the morphological diversity of branching patterns and transverse connections, and to understand how they change with age. Two types of branching morphologies were identified: lateral branching, resulting in small osteon branches bifurcating off of larger Haversian canals; and dichotomous branching, the formation of two new osteonal branches from one. The reconstructions in this study also suggest that Haversian systems frequently target previously existing systems as a path for their course, resulting in a cross-sectional morphology frequently referred to as 'type II osteons'. Transverse connections were diverse in their course from linear to oblique to curvy. Quantitative assessment of age-related trends indicates that while in younger human individuals transverse connections were most common, in older individuals more evidence of connections resulting from Haversian systems growing inside previously existing systems was found. Despite these changes in morphological characteristics, a relatively constant degree of overall interconnectivity is maintained throughout life. Altogether, the present study reveals important details about Haversian systems and their relation to each other that can be used towards a better understanding of cortical bone remodeling as well as a more accurate interpretation of morphological variants of osteons in cross-sectional microscopy. Permitting visibility of reversal lines, synchrotron radiation-based micro-CT is a valuable tool for the reconstruction of Haversian systems, and future analyses have the potential to further improve understanding of various important aspects of bone growth, maintenance and health.
Three dimensional reconstruction of haversian canals using X-ray micro-computed tomography
Bone, 2006
This study uses synchrotron radiation-based micro-computed tomography (CT) scans to reconstruct threedimensional networks of Haversian systems in human cortical bone in order to observe and analyse interconnectivity of Haversian systems and the development of total Haversian networks across different ages. A better knowledge of how Haversian systems interact with each other is essential to improve understanding of remodeling mechanisms and bone maintenance; however, previous methodological approaches (e.g. serial sections) did not reveal enough detail to follow the specific morphology of Haversian branching, for example. Accordingly, the aim of the present study was to identify the morphological diversity of branching patterns and transverse connections, and to understand how they change with age. Two types of branching morphologies were identified: lateral branching, resulting in small osteon branches bifurcating off of larger Haversian canals; and dichotomous branching, the formation of two new osteonal branches from one. The reconstructions in this study also suggest that Haversian systems frequently target previously existing systems as a path for their course, resulting in a cross-sectional morphology frequently referred to as 'type II osteons'. Transverse connections were diverse in their course from linear to oblique to curvy. Quantitative assessment of age-related trends indicates that while in younger human individuals transverse connections were most common, in older individuals more evidence of connections resulting from Haversian systems growing inside previously existing systems was found. Despite these changes in morphological characteristics, a relatively constant degree of overall interconnectivity is maintained throughout life. Altogether, the present study reveals important details about Haversian systems and their relation to each other that can be used towards a better understanding of cortical bone remodeling as well as a more accurate interpretation of morphological variants of osteons in cross-sectional microscopy. Permitting visibility of reversal lines, synchrotron radiation-based micro-CT is a valuable tool for the reconstruction of Haversian systems, and future analyses have the potential to further improve understanding of various important aspects of bone growth, maintenance and health.
Micron, 2021
Haversian systems result from bone remodeling, and show variation in size and shape among differing ages, body weights, mechanical environments, and species. While variables such as osteon circularity (On.Cr.) are generally studied in single transverse cross-sections, little is known about On.Cr. variation along an osteon's length, investigated here, in order to strengthen our understanding of bone microstructure. Materials and Methods: Up to 875 measurements of On.Cr. were generated for 41 osteonal segments from the proximal anterior diaphysis of femoral human cortical bone of three adult male samples (ages 46, 62, 74). We employed four hypotheses to investigate On.Cr. variability, in cross-section and longitudinally. H1: There is no difference in On.Cr. among osteons comprising single cross-sections, H2: There is no difference in On.Cr. among individuals when single cross-sections are compared, H3: There is no difference in On.Cr. among measurements taken from an osteon along the longitudinal axis, and H4: There is no discernable pattern in an osteon's deviation from circularity. Results: Quantitative analysis of single cross-sections revealed relatively consistent On.Cr. measurements within individual cross-sections and among individuals, supporting both, H1 and H2. Along individual osteonal segments, substantial degrees of dispersion from central tendencies were observed in 27 out of 41 analyzed osteons (despite relatively low overall standard deviations and interquartile ranges), leading to a rejection of H3. Qualitative characterization of morphological deviation from a "typical" circularity suggests a patterned deviation, leading also to a rejection of H4. Discussion: On.Cr. variation is discussed in the context of both, phenomena intrinsic to a given osteon (including repetitive, small perturbations at roughly 45 μm intervals), and extrinsic (including shared reversal sheaths, osteonal branching, transverse connections, and osteonal repathing). Interesting associations between On.Cr. and other characteristics of the local Haversian network emphasize the role of Haversian systems as integrated parts of a greater morphological complex.
Three-dimensional analysis of cortical bone structure using X-ray micro-computed tomography
Physica A: Statistical Mechanics and its Applications, 2004
We demonstrate the capability of X-ray micro-computed tomography to image the microstructure of human cortical bone. At 5 m voxel size we observe the complex morphology of the Haversian network in three dimensions. The local thickness of Haversian canals is measured using a maximal sphere algorithm and found to have a bimodal signature and a mean radius of 19:2 m. The intra-cortical porosity due to Haversian canals is measured as 3.0%. Both results are in agreement with traditional histomorphometric measurements. We show that at higher resolutions one can resolve the spatial distribution of lacunae in cortical bone.
Journal of Anatomy, 2008
Secondary intracortical remodeling of bone varies considerably among and within vertebrate skeletons. Although prior research has shed important light on its biomechanical significance, factors accounting for this variability remain poorly understood. We examined regional patterning of secondary osteonal bone in an ontogenetic series of wild-collected primates, at the midshaft femur and humerus of Chlorocebus (Cercopithecus) aethiops ( n = 32) and Hylobates lar ( n = 28), and the midshaft femur of Pan troglodytes ( n = 12). Our major objectives were: 1) to determine whether secondary osteonal bone exhibits significant regional patterning across inner, mid-cortical and outer circumferential cortical rings within cross-sections; and if so, 2) to consider the manner in which this regional patterning may reflect the influence of relative tissue age and other circumstances of bone growth. Using same field-of-view images of 100-μ m-thick cross-sections acquired in brightfield and circularly polarized light microscopy, we quantified the percent area of secondary osteonal bone (%HAV) for whole cross-sections and across the three circumferential rings within cross-sections. We expected bone areas with inner and middle rings to exhibit higher %HAV than the outer cortical ring within cross-sections, the latter comprising tissues of more recent depositional history. Observations of primary bone microstructural development provided an additional context in which to evaluate regional patterning of intracortical remodeling. Results demonstrated significant regional variability in %HAV within all skeletal sites. As predicted,%HAV was usually lowest in the outer cortical ring within cross-sections. However, regional patterning across inner vs. mid-cortical rings showed a more variable pattern across taxa, age classes, and skeletal sites examined. Observations of primary bone microstructure revealed that the distribution of endosteally deposited bone had an important influence on the patterning of secondary osteonal bone across rings. Further, when present, endosteal compacted coarse cancellous bone always exhibited some evidence of intracortical remodeling, even in those skeletal sites exhibiting comparatively low %HAV overall. These results suggest that future studies should consider the local developmental origin of bone regions undergoing secondary remodeling later in life, for an improved understanding of the manner in which developmental and mechanical factors may interact to produce the taxonomic and intraskeletal patterning of secondary bone remodelling in adults.
Mammalian cortical bone in tension is non-Haversian
Cortical bone, found in the central part of long bones like femur, is known to adapt to local mechanical stresses. This adaptation has been linked exclusively with Haversian remodelling involving bone resorption and formation of secondary osteons. Compared to primary/plexiform bone, the Haversian bone has lower stiffness, fatigue strength and fracture toughness, raising the question why nature prefers an adaptation that is detrimental to bone's primary function of bearing mechanical stresses. Here, we show that in the goat femur, Haversian remodelling occurs only at locations of high compressive stresses. At locations corresponding to high tensile stresses, we observe a microstructure that is non-Haversian. Compared with primary/plexiform bone, this microstructure's mineralisation is significantly higher with a distinctly different spatial pattern. Thus, the Haversian structure is an adaptation only to high compressive stresses rendering its inferior tensile properties irrelevant as the regions with high tensile stresses have a non-Haversian, apparently primary microstructure. OPEN SUBJECT AREAS: TISSUES BIOMEDICAL ENGINEERING BONE BIOLOGICAL PHYSICS
Bone hierarchical structure: spatial variation across length scales
Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials, 2022
Bone is a complex hierarchical biomineralized material, which is special amongst biominerals because it is replete with cells, namely, osteocytes. While bone has been scrutinized for centuries, many questions remain open and new research hints that the ultrastructure of bone, encompassing both the bone matrix itself and the embedded cell network, is much more heterogeneous than hitherto realized. A number of these new findings have been made thanks to the enormous developments in X-ray imaging that have occurred in recent decades, and there is promise that they will also allow many of the remaining open questions to be addressed. X-ray absorption or phase imaging affords high three-dimensional (3D) resolution and allows traversing the length scales of bone all the way down to the fine details of the lacuno-canalicular network housing the osteocytes. Multimodal X-ray imaging provides combined information covering both the length scales defined by the size of the measured volume and tomographic resolution, as well as those probed by the signal that is measured. In X-ray diffraction computed tomography (XRD-CT), for example, diffraction signals can be reconstructed tomographically, which offers detailed information about the spatial variations in the crystallographic properties of the bone biomineral. Orientational information can be obtained by tensor tomography. The combination of both small-angle X-ray scattering (SAXS) and wideangle X-ray scattering (WAXS) tensor tomography gives information on the orientation of bone nanostructure and crystals, respectively. These new technical developments promise that great strides towards understanding bone structure can be expected in the near future. In this review, recent findings that have resulted from X-ray imaging are highlighted and speculation is given on what can be expected to follow.
Journal of Applied Physiology, 2013
Jast J, Jasiuk I. Age-related changes in the 3D hierarchical structure of rat tibia cortical bone characterized by high-resolution micro-CT. .-Three-dimensional hierarchical structure of female Sprague-Dawley rat tibia cortical bone was characterized as a function of age , and 72 wk) using a high-resolution micro-computed tomography. At the whole bone level, 3-wk samples exhibited statistically significant differences in a mean total tissue volume, mean cortical bone volume, mean cortical bone volume density, mean periosteal perimeter, and mean cortical thickness (P Ͻ 0.05) compared with all other ages. At the tissue level, there was a statistically significant increase in a mean canal number density and a decrease in a mean canal volume and diameter between 3-wk and 12-wk samples. While no significant variations were found between mean canal lengths, there was a dependence of mean canal orientation on age. At the cell level, there were no statistically significant differences in a lacuna number density and a lacuna volume density, and all lacunae element-based parameters displayed no dependence on age across age. In addition, at the microstructural level, the cannular indexes were reported separately for anterior, posterior, medial, and lateral anatomic regions. From 3 to 32 wk of age, there existed significantly fewer canals per volume of bone in the medial region of the tibia vs. other cross-sectional quadrants. Although there were changes with age, there were no statistically significant differences in the mean canal volume, mean canal diameter, and mean canal length between the four anatomic regions. cortical bone; bone's hierarchical structure; high-resolution microcomputed tomography; canal network; osteocyte lacunae
Biomedical Engineering, 2010
The osteoporotic fractures are due to alteration of trabecular and/or cortical bone. As the trabecular bone analysis do not require images with high resolution, it has been largely investigated contrary to the cortical bone for which there are few studies. The porosity of the cortical bone is depending on canal network and the bone remodeling leads to a coalescence process of canals which progressively involve the degradation of bone quality. Most of parameters to characterize the canal network of cortical bone were derived from the trabecular bone micro-architecture parameters and do not characterize the canals locally for which the changes of shape and regularity are in relation to the remodelling intensity. In this preliminary study, new tri-dimensional (3D) features of shape and surface at the canal level are presented to better characterize the remodeling processes. For that, we used 16 cortical bone samples from human femurs. Three D images at 7.5 μm 3 of resolution were obtained by synchrotron radiation micro-CT (SR micro-CT) used as the reference method comparatively to desktop micro-CT usually used for bone exploration. Therefore, our goal is to compare these both modalities. Usual and global parameters about canal volume, surface, diameter, spacing and number derived from the trabecular bone analysis were performed. Two parameters were developed to better describe the complexity of the structure: one describing the shape of the canals Ca.s and one the regularity surface Ca.r. There are significant changes in shape and surface parameters on D micro-CT compared with those observed by the reference SR micro-CT whereas there was no difference for global parameters. Consequently, only high image quality, such as SR micro-CT modality could be used to characterize the cortical degradation process at a local level.
2012
Three-dimensional hierarchical structure of female Sprague-Dawley rat tibia cortical 11 bone was characterized as a function of age (3, 12, 32, 42, 60, and 72 weeks) using a high 12 resolution micro-computed tomography. At the whole bone level, 3 week samples exhibited 13 statistically significant differences in a mean total tissue volume, mean cortical bone volume, 14 mean cortical bone volume density, mean periosteal perimeter, and mean cortical thickness (p < 15 0.05) compared to all other ages. At the tissue level, there was a statistically significant increase 16 in a mean canal number density and a decrease in a mean canal volume and diameter between 3 17 week and 12 week samples. While no significant variations were found between mean canal 18 lengths, there was a dependence of mean canal orientation on age. At the cell level, there were no 19 statistically significant differences in a lacuna number density and a lacuna volume density, and 20 all lacunae element-based para...