Increased cochlear otic capsule thickness and intracortical canal porosity in the oim mouse model of osteogenesis imperfecta.

Osteogenesis imperfecta (OI or brittle bone disease) is a group of genetic disorders of the connective tissues caused mainly by mutations in the genes encoding collagen type I. Clinical manifestations of OI include skeletal fragility, bone deformities, and severe functional disabilities, such as hearing loss. Progressive hearing loss, usually beginning in childhood, affects approximately 70% of people with OI with more than half of the cases involving the inner ear. There is no cure for OI nor a treatment to ameliorate its corresponding hearing loss, and very little is known about the properties of OI ears. In this study, we investigate the morphology of the otic capsule and the cochlea in the inner ear of the oim mouse model of OI. High-resolution 3D images of 8-week old oim and WT inner ears were acquired using synchrotron microtomography. Volumetric morphometric measurements were conducted for the otic capsule, its intracortical canal network and osteocyte lacunae, and for the cochlear spiral ducts. Our results show that the morphology of the cochlea is preserved in the oim ears at 8 weeks of age but the otic capsule has a greater cortical thickness and altered intracortical bone porosity, with a larger number and volume density of highly branched canals in the oim otic capsule. These results portray a state of compromised bone quality in the otic capsule of the oim mice that may contribute to their hearing loss.

Morphometric analyses of clavicle's nutrient foramen.

PURPOSE: Fractures of the clavicle, which has an important location and function in the upper extremity and shoulder joint, compose 10% of all fracture cases. During the osteosynthesis of clavicle fractures and in the post-operative period of patients, considering the detailed morphometric and topographic properties of the nutrient foramen of clavicle is important to avoid the disruption of arterial nutrition of the clavicle and prevent unexpected injuries. The aim of this study was to investigate the morphometric properties of the nutrient foramen of clavicle in more detail using computedtomography images. METHODS: Computed tomography images of 116 healthy individuals (56 women/60 men) who had no pathology history were included in the presented study. Computed tomography images were reconstructed three-dimensionally using free-licensed Horos v3.3.3 software. Then, distances from clavicle's nutrient foramen to sternal end, anterior and posterior edges of the clavicle were measured. Statistical analyses were completed using SPSS v21 software. RESULTS: Our results demonstrated that the nutrient foramen of clavicle was located closer to the sternal end of the clavicle. The shortest distance to the sternal edge of clavicle was measured as 3.3 cm. Analyses of gender differences indicated that statistically significant differences were in favor of men. However, topographic properties of the clavicle's nutrient foramen were not affected by age. CONCLUSION: Nutrient foramen is mostly located closer to the sternal end of clavicle. Especially during osteosynthesis of clavicle fractures at the sternal end, maintaining the arterial supply of clavicle is of great importance for increasing the post-operative life quality of patients.

Using nutrient foramina to differentiate human from non-human long bone fragments in bioarchaeology and forensic anthropology.

Long bone shaft fragments can be found isolated in archaeological and forensic contexts, such as in mass fatality incidents. When diagnostic morphological landmarks are not visible, the assessment of a human or non-human origin of a bone fragment can be challenging. Further methods need to be developed. In long bones, the presence of a nutrient foramen on fragments that do not show any diagnostic landmarks can make the assessment of the origin of the bone still possible. In this paper, human long bones were compared to those of the following species: chicken (Gallus gallus domesticus), duck (Cairina moschata), sheep (Ovis aries), pig (Sus scrofa domesticus), and deer (fallow deer, Dama dama, and roe deer, Capreolus capreolus). Macroscopic evaluation of location, direction and appearance, and micro-CT scanning in order to measure angle and shape of canal entrance, were applied in this study to differentiate human from non-human nutrient foramina on long bone shafts. Observations regarding the location and direction of nutrient foramina were proven to be different between human and non-human bones; however, these two features might not be exploitable in cases of highly fragmented bones. The foramina appearance was the most reliable for the origin identification, although the shape of the canal entrance and its angle at the cortical bone, obtained from micro-CT scans, were also useful parameters. For a correct identification of a fragment, one parameter may not be enough and it is advisable to employ as many features as possible. This research demonstrates that nutrient foramina have potential as a reliable bone feature for the distinction between human and non-human fragmented and incomplete long bones.

Compositional and mechanical properties of growing cortical bone tissue: a study of the human fibula.

Human cortical bone contains two types of tissue: osteonal and interstitial tissue. Growing bone is not well-known in terms of its intrinsic material properties. To date, distinctions between the mechanical properties of osteonal and interstitial regions have not been investigated in juvenile bone and compared to adult bone in a combined dataset. In this work, cortical bone samples obtained from fibulae of 13 juveniles patients (4 to 18 years old) during corrective surgery and from 17 adult donors (50 to 95 years old) were analyzed. Microindentation was used to assess the mechanical properties of the extracellular matrix, quantitative microradiography was used to measure the degree of bone mineralization (DMB), and Fourier transform infrared microspectroscopy was used to evaluate the physicochemical modifications of bone composition (organic versus mineral matrix). Juvenile and adult osteonal and interstitial regions were analyzed for DMB, crystallinity, mineral to organic matrix ratio, mineral maturity, collagen maturity, carbonation, indentation modulus, indicators of yield strain and tissue ductility using a mixed model. We found that the intrinsic properties of the juvenile bone were not all inferior to those of the adult bone. Mechanical properties were also differently explained in juvenile and adult groups. The study shows that different intrinsic properties should be used in case of juvenile bone investigation.

Age-related properties at the microscale affect crack propagation in cortical bone.

The increased risk for fracture with age is associated not only with reduced bone mass but also with impaired bone quality. At the microscale, bone quality is related to porosity, microstructural organization, accumulated microdamage and intrinsic material properties. However, the link between these characteristics and fracture behavior is still missing. Bone tissue has a complex structure and as age-related compositional and structural changes occur at all hierarchical length scales it is difficult to experimentally identify and discriminate the effect of each mechanism. The aim of this study was therefore to use computational models to analyze how microscale characteristics in terms of porosity, intrinsic toughness properties and microstructural organization affect the mechanical behavior of cortical bone. Tensile tests were simulated using realistic microstructural geometries based on microscopy images of human cortical bone. Crack propagation was modelled using the extended finite element method where cement lines surrounding osteons were modelled with an interface damage law to capture crack deflections along osteon boundaries. Both increased porosity and impaired material integrity resulted in straighter crack paths with cracks penetrating osteons, similar to what is seen experimentally for old cortical bone. However, only the latter predicted a more brittle failure behavior. Furthermore, the local porosity influenced the crack path more than the macroscopic porosity. In conclusion, age-related changes in cortical bone affect the crack path and the mechanical response. However, increased porosity alone was not driving damage in old bone, but instead impaired tissue integrity was required to capture brittle failure in aging bone.

Histomorphometric age estimation from the femoral cortex: A test of three methods in an Australian population.

Histological methods can be used forensically to estimate age-at-death based on patterns of change in osteon shape, size, and population density, all of which result from the continuous process of bone remodelling. The present study examines the applicability of three existing histological age-at-death estimation methods as applied to an Australian population of known age and sex. Microradiographs from 50 mid-shaft femora thin sections, equally divided by sex, were obtained from the Melbourne Femur Reference Collection (MFRC); stated chronological age-at-death is 18 to 88 years. Osteon shape metrics are measured using ImageJ and the age-at-death prediction formulae of i) Singh and Gunberg, ii) Keough et al., and iii) Goliath et al. are applied. The relationship between estimated and actual age-at-death is then statistically quantified. All three formulae demonstrate pooled and sex-specific SEE values in excess of 20 years: i) pooled ±22.92 (♂±20.91, ♀±25.20); ii) ±20.79 (♂±20.96, ♀±21.05); and iii) ±35.43 (♂±32.68, ♀±38.66). When individuals under 40 years of age were excluded from the analysis, only two of the methods demonstrated increased accuracy: i) pooled ±20.87 (♂ ±17.47, ♀ ±23.70); ii) pooled ±18.21 (♂±16.51, ♀±19.90); and iii) pooled ±41.18 (♂ ±40.12, ♀ 43.05). The present study represents a preliminary investigation of the accuracy of existing histological age-at-death standards applied in an Australian population of known age.

Histological age-at-death estimation in white South Africans using stereology.

Various methods are available for estimating age from skeletal remains, amongst them the use of histomorphometry. It is generally argued that age estimation standards are population specific, but this in itself creates problems as the reference samples used are often not large enough and/or lack substantial representation of all age cohorts. Traditional age methods have been shown to suffer from problems such as age mimicry. This paper aims at establishing histological age-at-death standards for the white South African population by supplementing the available sample (lacking an adequate number of young adults) with another sample of European descent to avoid over-estimation of age in younger individuals caused by age mimicry. Bone microstructures related to the number of osteons and fragments, osteon size and Haversian canal size that change with advancing age were used for the development of regression formulae. A histomorphometric assessment of the anterior cortex of the femur was done using stereology for the estimation of age at death. All sections were analysed using the optical fractionator and nucleator probes. A sample of 94 bone sections (n = 50 male, n = 44 females) of white South African individuals were used. A sample of Danish individuals (n = 14 males, n = 16 females) was combined with the South African sample to create a normal age distribution for the reference sample. Single and multiple regression equations were developed after randomly selecting a hold-out sample (n = 14) for validation. Osteon size (average length, surface area and volume) showed the highest correlation with age, followed by the number of osteons and fragments per grid area. Haversian canal size showed inconsistent changes with advancing age. Using the regression equations, predicted ages were obtained for the 14 individuals. RMSE values ranged between 14 and 17 years, which we deemed acceptable.

3D analysis of the osteonal and interstitial tissue in human radii cortical bone.

Human cortical bone has a complex hierarchical structure that is periodically remodelled throughout a lifetime. This microstructure dictates the mechanical response of the tissue under a critical load. If only some structural features, such as the different porosities observed in bone, are primarily studied, then investigations may not fully consider the osteonal systems in three-dimensions (3D). Currently, it is difficult to differentiate osteons from interstitial tissue using standard 3D characterization methods. Synchrotron radiation micro-computed tomography (SR-µCT) in the phase contrast mode is a promising method for the investigation of osteons. In the current study, SR-µCT imaging was performed on cortical bone samples harvested from eight human radii (female, 50-91 y.o.). The images were segmented to identify Haversian canals, osteocyte lacunae, micro-cracks, as well as osteons. The significant correlation between osteonal and Haversian canal volume fraction highlights the role of the canals as sites where bone remodelling is initiated. The results showed that osteocyte lacunae morphometric parameters depend on their distance to cement lines, strongly suggesting the evolution of biological activity from the beginning to the end of the remodelling process. Thus, the current study provides new data on 3D osteonal morphometric parameters and their relationships with other structural features in humans.

Median Perforating Canal in Human Mandible.

Surgical interventions in the anterior region of the human mandible are associated with many complications. Some anatomical structures like the median perforating canal were discovered in mammals. Such canals may be a cause of concern that needs attention in human mandible. The purpose of the present study was to evaluate the occurrence, location, and course of median perforating canal and its associated extensions in the anterior segment of the human mandible in cone beam computed tomography scans (CBCT). Data were collected from 160 CBCT scans, and evaluated. The incidence was 23.75% for median perforating canal with wide anatomical variations concerning the related lingual and labial extensions. Median perforating canal and their associated lingual and labial foramina are frequently seen in human mandible. A thorough investigation of the symphyseal region using CBCT must be taken into account when targeting surgical intervention in this area.

Bone histomorphometric measures of physical activity in children from medieval England.

OBJECTIVES: Histomorphometric studies show consistent links between physical activity patterns and the microstructure underlying the size and shape of bone. Here, we adopt a combined bone approach to explore variation in microstructure of ribs and humeri related to physical activity and historical records of manual labor in skeletal samples of children (n = 175) from medieval England. The humerus reflects greater biomechanically induced microstructural variation than the rib which is used here as a control. Variation in microstructure is sought between regions in England (Canterbury, York, Newcastle), and between high- and low-status children from Canterbury. MATERIALS AND METHODS: Thin-sections were prepared from the humerus or rib and features of bone remodeling were recorded using high-resolution microscopy and image analysis software. RESULTS: The density and size of secondary osteons in the humerus differed significantly in children from Canterbury when compared to those from York and Newcastle. Among the older children, secondary osteon circularity and diameter differed significantly between higher and lower status children. DISCUSSION: By applying bone remodeling principles to the histomorphometric data, we infer that medieval children in Canterbury engaged in less physically demanding activities than children from York or Newcastle. Within Canterbury, high-status and low-status children experienced similar biomechanical loading until around 7 years of age. After this age low-status children performed activities that resulted in more habitual loading on their arm bones than the high-status children. This inferred change in physical activity is consistent with historical textual evidence that describes children entering the work force at this age.

Crack propagation in cortical bone is affected by the characteristics of the cement line: a parameter study using an XFEM interface damage model.

Bulk properties of cortical bone have been well characterized experimentally, and potent toughening mechanisms, e.g., crack deflections, have been identified at the microscale. However, it is currently difficult to experimentally measure local damage properties and isolate their effect on the tissue fracture resistance. Instead, computer models can be used to analyze the impact of local characteristics and structures, but material parameters required in computer models are not well established. The aim of this study was therefore to identify the material parameters that are important for crack propagation in cortical bone and to elucidate what parameters need to be better defined experimentally. A comprehensive material parameter study was performed using an XFEM interface damage model in 2D to simulate crack propagation around an osteon at the microscale. The importance of 14 factors (material parameters) on four different outcome criteria (maximum force, fracture energy, crack length and crack trajectory) was evaluated using ANOVA for three different osteon orientations. The results identified factors related to the cement line to influence the crack propagation, where the interface strength was important for the ability to deflect cracks. Crack deflection was also favored by low interface stiffness. However, the cement line properties are not well determined experimentally and need to be better characterized. The matrix and osteon stiffness had no or low impact on the crack pattern. Furthermore, the results illustrated how reduced matrix toughness promoted crack penetration of the cement line. This effect is highly relevant for the understanding of the influence of aging on crack propagation and fracture resistance in cortical bone.

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

DMP1 (dentin matrix protein 1) is an extracellular matrix protein highly expressed in bones. Studies of Dmp1 knockout (KO) mice led to the discovery of a rare autosomal recessive form of hypophosphatemic rickets (ARHR) caused by DMP1 mutations. However, there are limitations for using this mouse model to study ARHR, including a lack of Haversian canals and osteons (that occurs only in large mammalian bones), high levels of fibroblast growth factor 23 (FGF23), and PTH, in comparison with a moderate elevation of FGF23 and unchanged PTH in human ARHR patients. To better understand this rare disease, we deleted the DMP1 gene in rabbit using CRISPR/Cas9. This rabbit model recapitulated many features of human ARHR, such as the rachitic rosary (expansion of the anterior rib ends at the costochondral junctions), moderately increased FGF23, and normal PTH levels, as well as severe defects in bone mineralization. Unexpectedly, all DMP1 KO rabbits died by postnatal week 8. They developed a severe bone microarchitecture defect: a major increase in the central canal areas of osteons, concurrent with massive accumulation of osteoid throughout all bone matrix (a defect in mineralization), suggesting a new paradigm, where rickets is caused by a combination of a defect in bone microarchitecture and a failure in mineralization. Furthermore, a study of DMP1 KO bones found accelerated chondrogenesis, whereas ARHR has commonly been thought to be involved in reduced chondrogenesis. Our findings with newly developed DMP1 KO rabbits suggest a revised understanding of the mechanism underlying ARHR. © 2019 American Society for Bone and Mineral Research.

A study of intracortical porosity's area fractions and aspect ratios using computer vision and pulse-coupled neural networks.

Employing computer vision (CV) and optimized pulse-coupled neural networks (PCNN), this work automatically quantifies the geometrical attributes of intracortical bone porosity (namely lacunae and canaliculi (L-C), Haversian canals, and resorption cavities). Fifty pathological slides of cortical bone (× 20 magnification) were prepared from middiaphysis of bovine forelegs collected fresh from butcher. Biopsies were subdivided into sectors encircling arcs (θ of 10°) and radial distances (R) originating from the bone's geometric center toward posterior regions and spanning 3.3 mm. Microscopically, each pore is classified according to whether it belonged to primary or secondary osteon. Globally, each pore is assigned as being located in anterior or posterior regions. For each pore, area and major/minor axes lengths were determined as raw measures from which derived geometric measures, namely, area fraction (AF) and aspect ratio (AR), were derived. Said measures were plotted versus R (for different angles). Plots of AF and AR trends were found to vary linearly along the radial distance. Area fractions (%) significantly decreased linearly with R (p < 0.01) in the anterior region. In the posterior region, area fraction values are flat versus R. These findings are indicative of maturing osteons at the outer cortex with predominately near circular-shaped pores. Graphical abstract (Left) Grids of slides (magnified at 20X) of intra-cortical bone showing Lacunar-canalicular porosity (LCP). Areas marked with the dotted square represent a group of 25 images. The dashed line is a hand-drawn line that demarcates the anterior and posterior regions and the solid line is the best-fit arc radii (R =16.4 mm) of the dashed demarcation line. (Right) Images rotated in the polar coordinate system with their respective angles and radii shown.

Investigating interindividual variations in cortical bone quality: analysis of the morphotypes of secondary osteons and their population densities in the human femoral diaphysis.

Osteons are the primary sites of cortical bone lesions. However, many aspects of osteon microstructure remain poorly understood. This study aimed to explores interindividual differences in the osteon morphotype distributions in the human femoral diaphysis by evaluating the secondary osteon distributions in samples from human femurs. Two anonymized bone fragments from two modern Japanese femurs were examined. Twelve continuous transverse femoral diaphysis specimens were prepared from each fragment. Imaging examinations were conducted using a circularly polarized light microscope, and cross-sectional images were rendered using graphical synthesis software. Osteons in the images were identified as either bright-type osteons, dark-type osteons, or an others type. The two femurs were compared, and the secondary osteon morphotype distributions in different regions of their cross-sections were analyzed. When the two femurs were compared, significant differences in osteon density were observed in some regions and cross-sections. The dark-type osteon presence was strongest in the anterior and posterior regions of the femurs. The analytical method used in this study was found to be able to evaluate osteon microstructure. The results suggest that examining additional specimens and analyzing the biomechanical underpinnings of interindividual differences in osteon distribution patterns may help to improve our understanding of osteon microstructure.

3D micro structural analysis of human cortical bone in paired femoral diaphysis, femoral neck and radial diaphysis.

Human bone is known to adapt to its mechanical environment in a living body. Both its architecture and microstructure may differ between weight-bearing and non-weight-bearing bones. The aim of the current study was to analyze in three dimensions, the morphology of the multi-scale porosities on human cortical bone at different locations. Eight paired femoral diaphyses, femoral necks, and radial diaphyses were imaged using Synchrotron Radiation µCT with a 0.7 µm isotropic voxel size. The spatial resolution facilitates the investigation of the multiscale porosities of cortical bone, from the osteonal canals system down to the osteocyte lacunar system. Our results showed significant differences in the microstructural properties, regarding both osteonal canals and osteocytes lacunae, between the different anatomical locations. The radius presents significantly lower osteonal canal volume fraction and smaller osteonal canals than the femoral diaphysis or neck. Osteocytes lacunae observed in the radius are significantly different in shape than in the femur, and lacunar density is higher in the femoral neck. These results show that the radius, a non-weight-bearing bone, is significantly different in terms of its microstructure from a weight-bearing bone such as the femur. This implies that the cortical bone properties evaluated on the femoral diaphysis, the main location studied within the literature, cannot be generalized to other anatomical locations.

Brief communication: Test of a method to identify double-zonal osteon in polarized light microscopy.

OBJECTIVES: Double-zonal osteons (DZ) have been of interest in paleopathological research because they might be linked to physiological pathology. DZ are thought to be evidence of arrested osteon formation with a brief but abrupt increase in mineralization of lamellae occurring during bone remodeling. Originally identified from microradiographs as hypermineralized rings, recent studies have identified DZ from linear polarized light microscopy (PLM). However, PLM does not guarantee the adequate detection of DZ since PLM captures bone birefringence and not hyper-mineralization. Scanning electron microscopy with backscatter electrons (BSE-SEM) allows observation of DZ by detecting differences in mineralization. The purpose of this study is to investigate whether DZ, as identified by BSE-SEM, can indeed be identified with PLM. MATERIALS AND METHODS: The sample consists of an archaeological collection of adult midshaft femurs (n = 30) from St. Matthew cemetery, Quebec City (1771-1860). DZ were identified and counted independently with PLM and BSE-SEM for the same sections. Results from both methods were compared. RESULTS: Chi-square test shows that there was no significant difference between the two methods (p = 0.404). No significant bias was found on Bland-Altman analysis and Cohen's kappa shows a substantial agreement between the two methods (Κ = 0.66). PLM shows a good accuracy (sensitivity 79%, specificity 99.4%) and reliability (Positive Predictive Value: 86.71%; Negative Predictive Value: 99.45%). DISCUSSION: These findings indicate that the two methods are interchangeable. PLM, using our proposed protocol, is reliable to accurately identify DZ. We discuss how PLM and BSE-SEM that measure different features of the bone tissue can converge on the identification of DZ.

Enigma of scapular foramen and tunnels: an untold story.

PURPOSE: The study was undertaken to make a qualitative and quantitative assessment of unnamed foramen and tunnels in adult human scapulae with aid of plain and contrast radiographs. MATERIALS AND METHODS: A total of 120 dry bones, 60 each of the right and the left side were included in the study. Distribution of these foramina and tunnels was noted for their number, side, location, course and communication. Their morphometry was done using Vernier's caliper. RESULTS: Incidence of scapular foramina was 7.5% (R > L), whereas scapular tunnels were seen in 15.8% cases. Incidence of the sinuous, curved, and straight tunnels was found to be 50, 39, and 10.7% respectively. Left-sided tunnels were longer than the right ones. Plain and contrast radiographs were taken to confirm the findings. CONCLUSION: Anatomy literature describes only two scapular foramina, namely, nutrient foramen and suprascapular foramen/notch in a great zeal; occurrence of such anonymous foramina is hardly discussed. Through this study, there is an endeavor towards unfolding the mystery of scapular foramina in terms of their morphometry and distribution, the knowledge of which will aid clinicians, forensic experts, and surgeons in better diagnosis and management of clinical cases.

Differentiating human versus non-human bone by exploring the nutrient foramen: implications for forensic anthropology.

One of the roles of a forensic anthropologist is to assist medico-legal investigations in the identification of human skeletal remains. In some instances, only small fragments of bone may be present. In this study, a non-destructive novel technique is presented to distinguish between human and non-human long bones. This technique is based on the macroscopic and computed tomography (CT) analysis of nutrient foramina. The nutrient foramen of long bone diaphyses transmits the nutrient artery which provides much of the oxygen and nutrients to the bone. The nutrient foramen and its canal were analysed in six femora and humeri of human, sheep (Ovies aries) and pig (Sus scrofa) species. The location, position and direction of the nutrient foramina were measured macroscopically. The length of the canal, angle of the canal, circumference and area of the entrance of the foramen were measured from CT images. Macroscopic analysis revealed the femora nutrient foramina are more proximal, whereas humeri foramina are more distal. The human bones and sheep humerus conform to the perceived directionality, but the pig bones and sheep femur do not. Amongst the parameters measured in the CT analysis, the angle of the canal had a discriminatory power. This study shows the potential of this technique to be used independently or complementary to other methods in distinguishing between human and non-human bone in forensic anthropology.

Occurrence of osteon banding in adult human cortical bone.

OBJECTIVES: Differentiating human from nonhuman fragmented bone is often accomplished using histological methods if the observation of gross morphology proves insufficient. Linearly oriented primary and/or secondary osteonal systems, commonly referred to as osteon bands, are described as a strong indicator of nonhuman bone, particularly the occurrence of multiple bands. This phenomenon has been conventionally documented using two-dimensional (2D) histology, but such analyses are destructive and typically limited to a single cross-section. Progressive developments in high-resolution X-ray imaging, however, allow for the nondestructive three-dimensional (3D) visualization of bone microarchitecture. The primary objective of the current research was to visualize and document the occurrence of osteon banding in adult human cortical bone using high-resolution synchrotron radiation-based micro-Computed Tomography (SR micro-CT). MATERIALS AND METHODS: Synchrotron radiation-based micro-CT scanning was carried out at the Canadian Light Source (CLS) national synchrotron facility. The presence or absence of osteon banding was visualized in human skeletal elements from three adult males with representative samples from all regions of the skeleton (n = 129). If present, osteon banding was described and quantified. RESULTS: Results indicated that 23 of 129 human cortical bone specimens exhibited osteon banding, representing 18% of the sample. Linear arrangements of primary and/or secondary osteons were observed in the following skeletal elements: temporal, parietal, frontal, occipital, clavicle, mandible, femur, tibia, ulna, second metatarsal, and sacrum. DISCUSSION: The present work represents the first 3D examination of inter-element variation in osteon banding in adult human cortical bone. Findings indicate that the presence of multiple osteon bands in a single specimen is not diagnostic of nonhuman bone. As such, osteon banding categorically should not be taken as evidence of nonhuman bone in forensic and archaeological contexts.

Chronic Alcohol Abuse Leads to Low Bone Mass with No General Loss of Bone Structure or Bone Mechanical Strength.

Chronic alcohol abuse (CAA) has deleterious effects on skeletal health. This study examined the impact of CAA on bone with regard to bone density, structure, and strength. Bone specimens from 42 individuals with CAA and 42 individuals without alcohol abuse were obtained at autopsy. Dual-energy X-ray absorptiometry (DEXA), compression testing, ashing, and bone histomorphometry were performed. Individuals with CAA had significantly lower bone mineral density (BMD) in the femoral neck and significantly lower bone volume demonstrated by thinner trabeculae, decreased extent of osteoid surfaces, and lower mean wall thickness of trabecular osteons compared to individuals without alcohol abuse. No significant difference was found for bone strength and structure. CONCLUSION: CAA leads to low bone mass due to a decrease in bone formation but with no destruction of bone architecture nor a decrease in bone strength. It is questionable whether this per se increases fracture risk.