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Sample records for trabecular bone apparent

  1. Bisphosphonate treatment affects trabecular bone apparent modulus through micro-architecture rather than matrix properties

    DEFF Research Database (Denmark)

    Ding, Ming

    2004-01-01

    and trabecular architecture independently. Conventional histomorphometry and microdamage data were obtained from the second and third lumbar vertebrae of the same dogs [Bone 28 (2001) 524]. Bisphosphonate treatment resulted in an increased apparent Young's modulus, decreased bone turnover, increased calcified...... matrix density, and increased microdamage. We could not detect any change in the effective Young's modulus of the calcified matrix in the bisphosphonate treated groups. The observed increase in apparent Young's modulus was due to increased bone mass and altered trabecular architecture rather than changes...... in the calcified matrix modulus. We hypothesize that the expected increase in the Young's modulus of the calcified matrix due to the increased calcified matrix density was counteracted by the accumulation of microdamage. Udgivelsesdato: 2004 May...

  2. Decreased trabecular bone biomechanical competence, apparent density, IGF-II and IGFBP-5 content in acromegaly

    DEFF Research Database (Denmark)

    Ueland, Thor; Ebbesen, Ebbe Nils; Thomsen, Jesper Skovhus

    2002-01-01

    of these growth factors in relation to biomechanical properties in acromegaly. MATERIALS AND METHODS: Trabecular bone biomechanical competence (compression test), apparent density (peripheral quantitative computed tomography, pQCT), and bone matrix contents of calcium (HCl hydrolysis) and IGFs (guanidinium......-HCl extraction) were measured in iliac crest biopsies from 13 patients with active acromegaly (two women and 11 men, aged 21-61 years) and 21 age- and sex-matched controls (four women and 17 men, aged 23-64 years). RESULTS: Trabecular bone pQCT was reduced in acromegalic patients compared with controls (P = 0...... bone content of IGF-I, IGFBP-3, or osteocalcin. However, IGF-II and IGFBP-5 content was decreased (P acromegaly, supporting previous observations...

  3. Tissue viscoelasticity is related to tissue composition but may not fully predict the apparent-level viscoelasticity in human trabecular bone – An experimental and finite element study

    DEFF Research Database (Denmark)

    Ojanen, X.; Tanska, P.; Malo, M. K.H.

    2017-01-01

    Trabecular bone is viscoelastic under dynamic loading. However, it is unclear how tissue viscoelasticity controls viscoelasticity at the apparent-level. In this study, viscoelasticity of cylindrical human trabecular bone samples (n = 11, male, age 18–78 years) from 11 proximal femurs were charact......). These findings indicate that bone tissue viscoelasticity is affected by tissue composition but may not fully predict the macroscale viscoelasticity in human trabecular bone....

  4. Influence of cortical endplates on ultrasonic properties of trabecular bone

    International Nuclear Information System (INIS)

    Kim, Yoon Mi; Lee, Kang Il

    2015-01-01

    The present study investigated the influence of thick cortical endplates on the ultrasonic properties of trabecular bone in a femur with a high fracture risk. Twelve trabecular bone samples were prepared from bovine femurs, and acrylic plates with thicknesses of 1.25, 1.80, and 2.75 mm were manufactured to simulate the cortical endplates using acrylic with a density and a sound speed similar to cortical bone. Although the thickness of the acrylic plates attached to the two sides of the trabecular bone increased, high correlations were observed between the speed of sound and the apparent bone density of the trabecular bone, with Pearson's correlation coefficients of 0.80-0.86. High correlations were also observed between the attenuation coefficient at 0.5 mm and the apparent bone density of the trabecular bone, with Pearson's correlation coefficients of 0.84-0.91. These results suggest that the speed of sound and attenuation coefficient at a specific frequency measured in a femur with relatively thick cortical endplates compared to the calcaneus could be used as indices for predicting the bone mineral density of the femur.

  5. Age variations in the properties of human tibial trabecular bone and cartilage

    DEFF Research Database (Denmark)

    Ding, Ming

    2000-01-01

    , such as apparent, apparent ash and collagen densities of human tibial trabecular bone have significant relationships with age. Tissue density and mineral concentration remain constant throughout life. Trabecular bone is tougher in the younger age, i.e. fracture requires more energy. Collagen density was the single......Initiated and motivated by clinical and scientific problems such as age-related bone fracture, prosthetic loosening, bone remodeling, and degenerative bone diseases, much significant research on the properties of trabecular bone has been carried out over the last two decades. This work has mainly...... focused on the central vertebral trabecular bone, while little is known about age-related changes in the properties of human peripheral (tibial) trabecular bone. Knowledge of the properties of peripheral (tibial) trabecular bone is of major importance for the understanding of degenerative diseases...

  6. Long range node-strut analysis of trabecular bone microarchitecture

    DEFF Research Database (Denmark)

    Schmah, Tanya; Marwan, Norbert; Thomsen, Jesper Skovhus

    2011-01-01

    PURPOSE: We present a new morphometric measure of trabecular bone microarchitecture, called mean node strength (NdStr), which is part of a newly developed approach called long range node-strut analysis. Our general aim is to describe and quantify the apparent "latticelike" microarchitecture of th...

  7. Age variations in the properties of human tibial trabecular bone

    DEFF Research Database (Denmark)

    Ding, Ming; Dalstra, M; Danielsen, CC

    1997-01-01

    We tested in compression specimens of human proximal tibial trabecular bone from 31 normal donors aged from 16 to 83 years and determined the mechanical properties, density and mineral and collagen content. Young's modulus and ultimate stress were highest between 40 and 50 years, whereas ultimate...... strain and failure energy showed maxima at younger ages. These age-related variations (except for failure energy) were non-linear. Tissue density and mineral concentration were constant throughout life, whereas apparent density (the amount of bone) varied with ultimate stress. Collagen density (the...... amount of collagen) varied with failure energy. Collagen concentration was maximal at younger ages but varied little with age. Our results suggest that the decrease in mechanical properties of trabecular bone such as Young's modulus and ultimate stress is mainly a consequence of the loss of trabecular...

  8. Trabecular bone structure and strength - remodelling and repair

    DEFF Research Database (Denmark)

    Mosekilde, Lis; Ebbesen, Ebbe Nils; Erikstrup, Lise Tornvig

    2000-01-01

    The strength of the spinal trabecular bone declines by a factor of 4-5 from the age of 20 to 80 years. At the same time, the volumetric (apparent) density declines by a factor of only 2. This discrepancy can be explained by the known power relationship between density and strength; this power rel......; and the hydraulic effect of the bone marrow. In order to answer these questions, more in vitro and in vivo studies on human bone in relation to aging, to immobilisation, to exercise and in relation to different treatment regimens are needed.......The strength of the spinal trabecular bone declines by a factor of 4-5 from the age of 20 to 80 years. At the same time, the volumetric (apparent) density declines by a factor of only 2. This discrepancy can be explained by the known power relationship between density and strength; this power...

  9. Trabecular bone deficits among Vietnamese immigrants.

    Science.gov (United States)

    Melton, L J; Marquez, M A; McCready, L K; Achenbach, S J; Riggs, B L; Amin, S; Khosla, S

    2011-05-01

    Compared to white women, lower areal bone mineral density (aBMD) in middle-aged Vietnamese immigrants is due to reduced trabecular volumetric bone mineral density (vBMD), which in turn is associated with greater trabecular separation along with lower estrogen levels. The epidemiology of osteoporosis in Asian populations is still poorly known, but we previously found a deficit in lumbar spine aBMD among postmenopausal Southeast Asian women, compared to white women, that persisted after correction for bone size. This issue was revisited using more sophisticated imaging techniques. Twenty Vietnamese immigrants (age, 44-79 years) were compared to 162 same-aged white women with respect to aBMD at the hip, spine and wrist, vBMD at the hip and spine by quantitative computed tomography and vBMD and bone microstructure at the ultradistal radius by high-resolution pQCT. Bone turnover and sex steroid levels were assessed in a subset (20 Vietnamese and 40 white women). The aBMD was lower at all sites among the Vietnamese women, but femoral neck vBMD did not differ from middle-aged white women. Significant differences in lumbar spine and ultradistal radius vBMD in the Vietnamese immigrants were due to lower trabecular vBMD, which was associated with increased trabecular separation. Bone resorption was elevated and bone formation depressed among the Vietnamese immigrants, although trends were not statistically significant. Serum estradiol was positively associated with trabecular vBMD in the Vietnamese women, but their estrogen levels were dramatically lower compared to white women. Although reported discrepancies in aBMD among Asian women are mainly an artifact of smaller bone size, we identified a specific deficit in the trabecular bone among a sample of Vietnamese immigrants that may be related to low estrogen levels and which needs further study.

  10. Prediction of mechanical properties of trabecular bone using quantitative MRI

    International Nuclear Information System (INIS)

    Lammentausta, E; Hakulinen, M A; Jurvelin, J S; Nieminen, M T

    2006-01-01

    Techniques for quantitative magnetic resonance imaging (MRI) have been developed for non-invasive estimation of the mineral density and structure of trabecular bone. The R* 2 relaxation rate (i.e. 1/T* 2 ) is sensitive to bone mineral density (BMD) via susceptibility differences between trabeculae and bone marrow, and by binarizing MRI images, structural variables, such as apparent bone volume fraction, can be assessed. In the present study, trabecular bone samples of human patellae were investigated in vitro at 1.5 T to determine the ability of MRI-derived variables (R* 2 and bone volume fraction) to predict the mechanical properties (Young's modulus, yield stress and ultimate strength). Further, the MRI variables were correlated with reference measurements of volumetric BMD and bone area fraction as determined with a clinical pQCT system. The MRI variables correlated significantly (p 2 and MRI-derived bone volume fraction further improved the prediction of yield stress and ultimate strength. Although pQCT showed a trend towards better prediction of the mechanical properties, current results demonstrate the feasibility of combined MR imaging of marrow susceptibility and bone volume fraction in predicting the mechanical strength of trabecular bone and bone mineral density

  11. Mechanical and morphological properties of trabecular bone samples obtained from third metacarpal bones of cadavers of horses with a bone fragility syndrome and horses unaffected by that syndrome.

    Science.gov (United States)

    Symons, Jennifer E; Entwistle, Rachel C; Arens, Amanda M; Garcia, Tanya C; Christiansen, Blaine A; Fyhrie, David P; Stover, Susan M

    2012-11-01

    To determine morphological and mechanical properties of trabecular bone of horses with a bone fragility syndrome (BFS; including silicate-associated osteoporosis). Cylindrical trabecular bone samples from the distal aspects of cadaveric third metacarpal bones of 39 horses (19 horses with a BFS [BFS bone samples] and 20 horses without a BFS [control bone samples]). Bone samples were imaged via micro-CT for determination of bone volume fraction; apparent and mean mineralized bone densities; and trabecular number, thickness, and separation. Bone samples were compressed to failure for determination of apparent elastic modulus and stresses, strains, and strain energy densities for yield, ultimate, and failure loads. Effects of BFS and age of horses on variables were determined. BFS bone samples had 25% lower bone volume fraction, 28% lower apparent density, 18% lower trabecular number and thickness, and 16% greater trabecular separation versus control bone samples. The BFS bone samples had 22% lower apparent modulus and 32% to 33% lower stresses, 10% to 18% lower strains, and 41 % to 52% lower strain energy densities at yield, ultimate, and failure loads, compared with control bone samples. Differences between groups of bone samples were not detected for mean mineral density and trabecular anisotropy. Results suggested that horses with a BFS had osteopenia and compromised trabecular bone function, consistent with bone deformation and pathological fractures that develop in affected horses. Effects of this BFS may be systemic, and bones other than those that are clinically affected had changes in morphological and mechanical properties.

  12. Trabecular bone in the calcaneus of runners.

    Directory of Open Access Journals (Sweden)

    Andrew Best

    Full Text Available Trabecular bone of the human calcaneus is subjected to extreme repetitive forces during endurance running and should adapt in response to this strain. To assess possible bone functional adaptation in the posterior region of the calcaneus, we recruited forefoot-striking runners (n = 6, rearfoot-striking runners (n = 6, and non-runners (n = 6, all males aged 20-41 for this institutionally approved study. Foot strike pattern was confirmed for each runner using a motion capture system. We obtained high resolution peripheral computed tomography scans of the posterior calcaneus for both runners and non-runners. No statistically significant differences were found between runners and nonrunners or forefoot strikers and rearfoot strikers. Mean trabecular thickness and mineral density were greatest in forefoot runners with strong effect sizes (<0.80. Trabecular thickness was positively correlated with weekly running distance (r2 = 0.417, p<0.05 and years running (r2 = 0.339, p<0.05 and negatively correlated with age at onset of running (r2 = 0.515, p<0.01 Trabecular thickness, mineral density and bone volume ratio of nonrunners were highly correlated with body mass (r2 = 0.824, p<0.05 and nonrunners were significantly heavier than runners (p<0.05. Adjusting for body mass revealed significantly thicker trabeculae in the posterior calcaneus of forefoot strikers, likely an artifact of greater running volume and earlier onset of running in this subgroup; thus, individuals with the greatest summative loading stimulus had, after body mass adjustment, the thickest trabeculae. Further study with larger sample sizes is necessary to elucidate the role of footstrike on calcaneal trabecular structure. To our knowledge, intraspecific body mass correlations with measures of trabecular robusticity have not been reported elsewhere. We hypothesize that early adoption of running and years of sustained moderate volume running stimulate bone modeling in trabeculae of the

  13. Trabecular bone in the calcaneus of runners.

    Science.gov (United States)

    Best, Andrew; Holt, Brigitte; Troy, Karen; Hamill, Joseph

    2017-01-01

    Trabecular bone of the human calcaneus is subjected to extreme repetitive forces during endurance running and should adapt in response to this strain. To assess possible bone functional adaptation in the posterior region of the calcaneus, we recruited forefoot-striking runners (n = 6), rearfoot-striking runners (n = 6), and non-runners (n = 6), all males aged 20-41 for this institutionally approved study. Foot strike pattern was confirmed for each runner using a motion capture system. We obtained high resolution peripheral computed tomography scans of the posterior calcaneus for both runners and non-runners. No statistically significant differences were found between runners and nonrunners or forefoot strikers and rearfoot strikers. Mean trabecular thickness and mineral density were greatest in forefoot runners with strong effect sizes (forefoot strikers, likely an artifact of greater running volume and earlier onset of running in this subgroup; thus, individuals with the greatest summative loading stimulus had, after body mass adjustment, the thickest trabeculae. Further study with larger sample sizes is necessary to elucidate the role of footstrike on calcaneal trabecular structure. To our knowledge, intraspecific body mass correlations with measures of trabecular robusticity have not been reported elsewhere. We hypothesize that early adoption of running and years of sustained moderate volume running stimulate bone modeling in trabeculae of the posterior calcaneus.

  14. Relationship between tissue stiffness and degree of mineralization of developing trabecular bone

    NARCIS (Netherlands)

    Mulder, L.; Koolstra, J.H.; den Toonder, J.M.J.; van Eijden, T.M.G.J.

    2008-01-01

    It is unknown how the degree of mineralization of bone in individual trabecular elements is related to the corresponding mechanical properties at the bone tissue level. Understanding this relationship is important for the comprehension of the mechanical behavior of bone at both the apparent and

  15. Rationale for the evaluation of trabecular bone turnover

    International Nuclear Information System (INIS)

    Kimmel, D.B.; Jee, W.S.S.

    1976-01-01

    A procedure for the morphometric evaluation of trabecular bone is identified. Its scrupulous use allows total identification of bone formation and resorption rates, items necessary for the direct histologic analysis of bone turnover

  16. Biomechanics and Mechanobiology of Trabecular Bone: A Review

    Science.gov (United States)

    Oftadeh, Ramin; Perez-Viloria, Miguel; Villa-Camacho, Juan C.; Vaziri, Ashkan; Nazarian, Ara

    2015-01-01

    Trabecular bone is a highly porous, heterogeneous, and anisotropic material which can be found at the epiphyses of long bones and in the vertebral bodies. Studying the mechanical properties of trabecular bone is important, since trabecular bone is the main load bearing bone in vertebral bodies and also transfers the load from joints to the compact bone of the cortex of long bones. This review article highlights the high dependency of the mechanical properties of trabecular bone on species, age, anatomic site, loading direction, and size of the sample under consideration. In recent years, high resolution micro finite element methods have been extensively used to specifically address the mechanical properties of the trabecular bone and provide unique tools to interpret and model the mechanical testing experiments. The aims of the current work are to first review the mechanobiology of trabecular bone and then present classical and new approaches for modeling and analyzing the trabecular bone microstructure and macrostructure and corresponding mechanical properties such as elastic properties and strength. PMID:25412137

  17. INAA of cortical and trabecular bone samples from animals

    International Nuclear Information System (INIS)

    Takata, M.K.; Saiki, M.

    2004-01-01

    Instrumental neutron activation analysis (INAA) was applied to determine Ba, Br, Ca, Cl, Fe, K, Mg, Mn, Na, P, Sr and Zn in bovine and porcine rib bones. Precise results were obtained in analyses of freeze-dried cortical and trabecular bones separately, and also of whole bone ashes. Cortical tissues presented higher concentrations of Ba, Ca, Mg, Mn, Na, P, Sr and Zn than those obtained in trabecular ones. Comparisons were also made between the results obtained for bovine and porcine rib bones. (author)

  18. Mechanical properties of femoral trabecular bone in dogs

    Directory of Open Access Journals (Sweden)

    Nolte Ingo

    2005-03-01

    Full Text Available Abstract Background Studying mechanical properties of canine trabecular bone is important for a better understanding of fracture mechanics or bone disorders and is also needed for numerical simulation of canine femora. No detailed data about elastic moduli and degrees of anisotropy of canine femoral trabecular bone has been published so far, hence the purpose of this study was to measure the elastic modulus of trabecular bone in canine femoral heads by ultrasound testing and to assess whether assuming isotropy of the cancellous bone in femoral heads in dogs is a valid simplification. Methods From 8 euthanized dogs, both femora were obtained and cubic specimens were cut from the centre of the femoral head which were oriented along the main pressure and tension trajectories. The specimens were tested using a 100 MHz ultrasound transducer in all three orthogonal directions. The directional elastic moduli of trabecular bone tissue and degrees of anisotropy were calculated. Results The elastic modulus along principal bone trajectories was found to be 11.2 GPa ± 0.4, 10.5 ± 2.1 GPa and 10.5 ± 1.8 GPa, respectively. The mean density of the specimens was 1.40 ± 0.09 g/cm3. The degrees of anisotropy revealed a significant inverse relationship with specimen densities. No significant differences were found between the elastic moduli in x, y and z directions, suggesting an effective isotropy of trabecular bone tissue in canine femoral heads. Discussion This study presents detailed data about elastic moduli of trabecular bone tissue obtained from canine femoral heads. Limitations of the study are the relatively small number of animals investigated and the measurement of whole specimen densities instead of trabecular bone densities which might lead to an underestimation of Young's moduli. Publications on elastic moduli of trabecular bone tissue present results that are similar to our data. Conclusion This study provides data about directional elastic

  19. Measurement of the speed of sound in trabecular bone by using a time reversal acoustics focusing system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang Il [Kangwon National University, Chuncheon (Korea, Republic of); Choi, Bok-Kyoung [Maritime Security Research Center, KIOST, Ansan (Korea, Republic of)

    2014-10-15

    A new method for measuring the speed of sound (SOS) in trabecular bone by using a time reversal acoustics (TRA) focusing system was proposed and validated with measurements obtained by using the conventional pulse-transmission technique. The SOS measured in 14 bovine femoral trabecular bone samples by using the two methods was highly correlated each other, although the SOS measured by using the TRA focusing system was slightly lower by an average of 2.2 m/s. The SOS measured by using the two methods showed high correlation coefficients of r = 0.92 with the apparent bone density, consistent with the behavior in human trabecular bone in vitro. These results prove the efficacy of the new method based on the principle of TRA to measure the SOS in trabecular bone.

  20. FRACTAL ANALYSIS OF TRABECULAR BONE: A STANDARDISED METHODOLOGY

    Directory of Open Access Journals (Sweden)

    Ian Parkinson

    2011-05-01

    Full Text Available A standardised methodology for the fractal analysis of histological sections of trabecular bone has been established. A modified box counting method has been developed for use on a PC based image analyser (Quantimet 500MC, Leica Cambridge. The effect of image analyser settings, magnification, image orientation and threshold levels, was determined. Also, the range of scale over which trabecular bone is effectively fractal was determined and a method formulated to objectively calculate more than one fractal dimension from the modified Richardson plot. The results show that magnification, image orientation and threshold settings have little effect on the estimate of fractal dimension. Trabecular bone has a lower limit below which it is not fractal (λ<25 μm and the upper limit is 4250 μm. There are three distinct fractal dimensions for trabecular bone (sectional fractals, with magnitudes greater than 1.0 and less than 2.0. It has been shown that trabecular bone is effectively fractal over a defined range of scale. Also, within this range, there is more than 1 fractal dimension, describing spatial structural entities. Fractal analysis is a model independent method for describing a complex multifaceted structure, which can be adapted for the study of other biological systems. This may be at the cell, tissue or organ level and compliments conventional histomorphometric and stereological techniques.

  1. Prediction of trabecular bone qualitative properties using scanning quantitative ultrasound

    Science.gov (United States)

    Qin, Yi-Xian; Lin, Wei; Mittra, Erik; Xia, Yi; Cheng, Jiqi; Judex, Stefan; Rubin, Clint; Müller, Ralph

    2013-11-01

    Microgravity induced bone loss represents a critical health problem in astronauts, particularly occurred in weight-supporting skeleton, which leads to osteopenia and increase of fracture risk. Lack of suitable evaluation modality makes it difficult for monitoring skeletal status in long term space mission and increases potential risk of complication. Such disuse osteopenia and osteoporosis compromise trabecular bone density, and architectural and mechanical properties. While X-ray based imaging would not be practical in space, quantitative ultrasound may provide advantages to characterize bone density and strength through wave propagation in complex trabecular structure. This study used a scanning confocal acoustic diagnostic and navigation system (SCAN) to evaluate trabecular bone quality in 60 cubic trabecular samples harvested from adult sheep. Ultrasound image based SCAN measurements in structural and strength properties were validated by μCT and compressive mechanical testing. This result indicated a moderately strong negative correlations observed between broadband ultrasonic attenuation (BUA) and μCT-determined bone volume fraction (BV/TV, R2=0.53). Strong correlations were observed between ultrasound velocity (UV) and bone's mechanical strength and structural parameters, i.e., bulk Young's modulus (R2=0.67) and BV/TV (R2=0.85). The predictions for bone density and mechanical strength were significantly improved by using a linear combination of both BUA and UV, yielding R2=0.92 for BV/TV and R2=0.71 for bulk Young's modulus. These results imply that quantitative ultrasound can characterize trabecular structural and mechanical properties through measurements of particular ultrasound parameters, and potentially provide an excellent estimation for bone's structural integrity.

  2. Osteoporosis imaging: effects of bone preservation on MDCT-based trabecular bone microstructure parameters and finite element models

    International Nuclear Information System (INIS)

    Baum, Thomas; Grande Garcia, Eduardo; Burgkart, Rainer; Gordijenko, Olga; Liebl, Hans; Jungmann, Pia M.; Gruber, Michael; Zahel, Tina; Rummeny, Ernst J.; Waldt, Simone; Bauer, Jan S.

    2015-01-01

    Osteoporosis is defined as a skeletal disorder characterized by compromised bone strength due to a reduction of bone mass and deterioration of bone microstructure predisposing an individual to an increased risk of fracture. Trabecular bone microstructure analysis and finite element models (FEM) have shown to improve the prediction of bone strength beyond bone mineral density (BMD) measurements. These computational methods have been developed and validated in specimens preserved in formalin solution or by freezing. However, little is known about the effects of preservation on trabecular bone microstructure and FEM. The purpose of this observational study was to investigate the effects of preservation on trabecular bone microstructure and FEM in human vertebrae. Four thoracic vertebrae were harvested from each of three fresh human cadavers (n = 12). Multi-detector computed tomography (MDCT) images were obtained at baseline, 3 and 6 month follow-up. In the intervals between MDCT imaging, two vertebrae from each donor were formalin-fixed and frozen, respectively. BMD, trabecular bone microstructure parameters (histomorphometry and fractal dimension), and FEM-based apparent compressive modulus (ACM) were determined in the MDCT images and validated by mechanical testing to failure of the vertebrae after 6 months. Changes of BMD, trabecular bone microstructure parameters, and FEM-based ACM in formalin-fixed and frozen vertebrae over 6 months ranged between 1.0–5.6 % and 1.3–6.1 %, respectively, and were not statistically significant (p > 0.05). BMD, trabecular bone microstructure parameters, and FEM-based ACM as assessed at baseline, 3 and 6 month follow-up correlated significantly with mechanically determined failure load (r = 0.89–0.99; p < 0.05). The correlation coefficients r were not significantly different for the two preservation methods (p > 0.05). Formalin fixation and freezing up to six months showed no significant effects on trabecular bone microstructure

  3. Osteoarthritis alters the patellar bones subchondral trabecular architecture.

    Science.gov (United States)

    Hoechel, Sebastian; Deyhle, Hans; Toranelli, Mireille; Müller-Gerbl, Magdalena

    2017-09-01

    Following the principles of "morphology reveals biomechanics," the cartilage-osseous interface and the trabecular network show defined adaptation in response to physiological loading. In the case of a compromised relationship, the ability to support the load diminishes and the onset of osteoarthritis (OA) may arise. To describe and quantify the changes within the subchondral bone plate (SBP) and trabecular architecture, 10 human OA patellae were investigated by CT and micro-CT. The results are presented in comparison to a previously published dataset of 10 non-OA patellae which were evaluated in the same manner. The analyzed OA samples showed no distinctive mineralization pattern in regards to the physiological biomechanics, but a highly irregular disseminated distribution. In addition, no regularity in bone distribution and architecture across the trabecular network was found. We observed a decrease of material as the bone volume and trabecular thickness/number were significantly reduced. In comparison to non-OA samples, greatest differences for all parameters were found within the first mm of trabecular bone. The differences decreased toward the fifth mm in a logarithmic manner. The interpretation of the logarithmic relation leads to the conclusion that the main impact of OA on bony structures is located beneath the SBP and lessens with depth. In addition to the clear difference in material with approximately 12% less bone volume in the first mm in OA patellae, the architectural arrangement is more rod-like and isotropic, accounting for an architectural decrease in stability and support. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1982-1989, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  4. Quantitative computed tomography in measurement of vertebral trabecular bone mass

    International Nuclear Information System (INIS)

    Nilsson, M.; Johnell, O.; Jonsson, K.; Redlund-Johnell, I.

    1988-01-01

    Measurement of bone mineral concentration (BMC) can be done by several modalities. Quantitative computed tomography (QCT) can be used for measurements at different sites and with different types of bone (trabecular-cortical). This study presents a modified method reducing the influence of fat. Determination of BMC was made from measurements with single-energy computed tomography (CT) of the mean Hounsfield number in the trabecular part of the L1 vertebra. The method takes into account the age-dependent composition of the trabecular part of the vertebra. As the amount of intravertebral fat increases with age, the effective atomic number for these parts decreases. This results in a non-linear calibration curve for single-energy CT. Comparison of BMC values using the non-linear calibration curve or the traditional linear calibration with those obtained with a pixel-by-pixel based electron density calculation method (theoretically better) showed results clearly in favor of the non-linear method. The material consisted of 327 patients aged 6 to 91 years, of whom 197 were considered normal. The normal data show a sharp decrease in trabecular bone after the age of 50 in women. In men a slower decrease was found. The vertebrae were larger in men than in women. (orig.)

  5. Creep of trabecular bone from the human proximal tibia

    Energy Technology Data Exchange (ETDEWEB)

    Novitskaya, Ekaterina, E-mail: eevdokim@ucsd.edu [Mechanical and Aerospace Engineering, UC, San Diego, La Jolla, CA 92093 (United States); Materials Science and Engineering Program, UC, San Diego, La Jolla, CA 92093 (United States); Zin, Carolyn [Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218 (United States); Chang, Neil; Cory, Esther; Chen, Peter [Departments of Bioengineering and Orthopaedic Surgery, UC, San Diego, La Jolla, CA 92093 (United States); D’Lima, Darryl [Shiley Center for Orthopaedic Research and Education, Scripps Health, La Jolla, CA 92037 (United States); Sah, Robert L. [Materials Science and Engineering Program, UC, San Diego, La Jolla, CA 92093 (United States); Departments of Bioengineering and Orthopaedic Surgery, UC, San Diego, La Jolla, CA 92093 (United States); McKittrick, Joanna [Mechanical and Aerospace Engineering, UC, San Diego, La Jolla, CA 92093 (United States); Materials Science and Engineering Program, UC, San Diego, La Jolla, CA 92093 (United States)

    2014-07-01

    Creep is the deformation that occurs under a prolonged, sustained load and can lead to permanent damage in bone. Creep in bone is a complex phenomenon and varies with type of loading and local mechanical properties. Human trabecular bone samples from proximal tibia were harvested from a 71-year old female cadaver with osteoporosis. The samples were initially subjected to one cycle load up to 1% strain to determine the creep load. Samples were then loaded in compression under a constant stress for 2 h and immediately unloaded. All tests were conducted with the specimens soaked in phosphate buffered saline with proteinase inhibitors at 37 °C. Steady state creep rate and final creep strain were estimated from mechanical testing and compared with published data. The steady state creep rate correlated well with values obtained from bovine tibial and human vertebral trabecular bone, and was higher for lower density samples. Tissue architecture was analyzed by micro-computed tomography (μCT) both before and after creep testing to assess creep deformation and damage accumulated. Quantitative morphometric analysis indicated that creep induced changes in trabecular separation and the structural model index. A main mode of deformation was bending of trabeculae. - Highlights: • Compressive creep tests of human trabecular bone across the tibia were performed. • The creep rate was found to be inversely proportional to the density of the samples. • μ-computed tomography before and after testing identified regions of deformation. • Bending of the trabeculae was found to be the main deformation mode.

  6. Creep of trabecular bone from the human proximal tibia.

    Science.gov (United States)

    Novitskaya, Ekaterina; Zin, Carolyn; Chang, Neil; Cory, Esther; Chen, Peter; D'Lima, Darryl; Sah, Robert L; McKittrick, Joanna

    2014-07-01

    Creep is the deformation that occurs under a prolonged, sustained load and can lead to permanent damage in bone. Creep in bone is a complex phenomenon and varies with type of loading and local mechanical properties. Human trabecular bone samples from proximal tibia were harvested from a 71-year old female cadaver with osteoporosis. The samples were initially subjected to one cycle load up to 1% strain to determine the creep load. Samples were then loaded in compression under a constant stress for 2h and immediately unloaded. All tests were conducted with the specimens soaked in phosphate buffered saline with proteinase inhibitors at 37 °C. Steady state creep rate and final creep strain were estimated from mechanical testing and compared with published data. The steady state creep rate correlated well with values obtained from bovine tibial and human vertebral trabecular bone, and was higher for lower density samples. Tissue architecture was analyzed by micro-computed tomography (μCT) both before and after creep testing to assess creep deformation and damage accumulated. Quantitative morphometric analysis indicated that creep induced changes in trabecular separation and the structural model index. A main mode of deformation was bending of trabeculae. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Evaluation of trabecular bone patterns on dental radiographic images: influence of cortical bone

    Science.gov (United States)

    Amouriq, Yves; Evenou, Pierre; Arlicot, Aurore; Normand, Nicolas; Layrolle, Pierre; Weiss, Pierre; Guédon, Jean-Pierre

    2010-03-01

    For some authors trabecular bone is highly visible in intraoral radiographs. For other authors, the observed intrabony trabecular pattern is a representation of only the endosteal surface of cortical bone, not of intermedullary striae. The purpose of this preliminary study was to investigate the true anatomical structures that are visible in routine dental radiographs and classically denoted trabecular bone. This is a major point for bone texture analysis on radiographs. Computed radiography (CR) images of dog mandible section in molar region were compared with simulations calculated from high-resolution micro-CT volumes. Calculated simulations were obtained using the Mojette Transform. By digitally editing the CT volume, the simulations were separated into trabecular and cortical components into a region of interest. Different images were compared and correlated, some bone micro-architecture parameters calculated. A high correlation was found between computed radiographs and calculated simulations from micro-CT. The Mojette transform was successful to obtain high quality images. Cortical bone did not contribute to change in a major way simulated images. These first results imply that intrabony trabecular pattern observed on radiographs can not only be a representation of the cortical bone endosteal surface and that trabecular bone is highly visible in intraoral radiographs.

  8. Comparison of different plasticity criteria for trabecular bone failure modelling

    Czech Academy of Sciences Publication Activity Database

    Jiroušek, Ondřej

    2008-01-01

    Roč. 8, č. 1 (2008), s. 10177-10178 ISSN 1617-7061. [Annual Meeting of International Association of Applied Mathematics and Mechanics. Bremen, 31.03.2008-04.04.2008] R&D Projects: GA ČR(CZ) GA103/05/1020 Institutional research plan: CEZ:AV0Z20710524 Keywords : nanoindentation * plasticity criteria * trabecular bone Subject RIV: FI - Traumatology, Orthopedics

  9. Bone apatite composition of necrotic trabecular bone in the femoral head of immature piglets.

    Science.gov (United States)

    Aruwajoye, Olumide O; Kim, Harry K W; Aswath, Pranesh B

    2015-04-01

    Ischemic osteonecrosis of the femoral head (IOFH) can lead to excessive resorption of the trabecular bone and collapse of the femoral head as a structure. A well-known mineral component to trabecular bone is hydroxyapatite, which can be present in many forms due to ionic substitution, thus altering chemical composition. Unfortunately, very little is known about the chemical changes to bone apatite following IOFH. We hypothesized that the apatite composition changes in necrotic bone possibly contribute to increased osteoclast resorption and structural collapse of the femoral head. The purpose of this study was to assess the macroscopic and local phosphate composition of actively resorbed necrotic trabecular bone to isolate differences between areas of increased osteoclast resorption and normal bone formation. A piglet model of IOFH was used. Scanning electron microscopy (SEM), histology, X-ray absorbance near edge structure (XANES), and Raman spectroscopy were performed on femoral heads to characterize normal and necrotic trabecular bone. Backscattered SEM, micro-computed tomography and histology showed deformity and active resorption of necrotic bone compared to normal. XANES and Raman spectroscopy obtained from actively resorbed necrotic bone and normal bone showed increased carbonate-to-phosphate content in the necrotic bone. The changes in the apatite composition due to carbonate substitution may play a role in the increased resorption of necrotic bone due to its increase in solubility. Indeed, a better understanding of the apatite composition of necrotic bone could shed light on osteoclast activity and potentially improve therapeutic treatments that target excessive resorption of bone.

  10. Automatic analysis of trabecular bone structure from knee MRI

    DEFF Research Database (Denmark)

    Marques, Joselene; Granlund, Rabia; Lillholm, Martin

    2012-01-01

    We investigated the feasibility of quantifying osteoarthritis (OA) by analysis of the trabecular bone structure in low-field knee MRI. Generic texture features were extracted from the images and subsequently selected by sequential floating forward selection (SFFS), following a fully automatic......, uncommitted machine-learning based framework. Six different classifiers were evaluated in cross-validation schemes and the results showed that the presence of OA can be quantified by a bone structure marker. The performance of the developed marker reached a generalization area-under-the-ROC (AUC) of 0...

  11. An adaptation model for trabecular bone at different mechanical levels

    Directory of Open Access Journals (Sweden)

    Lv Linwei

    2010-07-01

    Full Text Available Abstract Background Bone has the ability to adapt to mechanical usage or other biophysical stimuli in terms of its mass and architecture, indicating that a certain mechanism exists for monitoring mechanical usage and controlling the bone's adaptation behaviors. There are four zones describing different bone adaptation behaviors: the disuse, adaptation, overload, and pathologic overload zones. In different zones, the changes of bone mass, as calculated by the difference between the amount of bone formed and what is resorbed, should be different. Methods An adaptation model for the trabecular bone at different mechanical levels was presented in this study based on a number of experimental observations and numerical algorithms in the literature. In the proposed model, the amount of bone formation and the probability of bone remodeling activation were proposed in accordance with the mechanical levels. Seven numerical simulation cases under different mechanical conditions were analyzed as examples by incorporating the adaptation model presented in this paper with the finite element method. Results The proposed bone adaptation model describes the well-known bone adaptation behaviors in different zones. The bone mass and architecture of the bone tissue within the adaptation zone almost remained unchanged. Although the probability of osteoclastic activation is enhanced in the overload zone, the potential of osteoblasts to form bones compensate for the osteoclastic resorption, eventually strengthening the bones. In the disuse zone, the disuse-mode remodeling removes bone tissue in disuse zone. Conclusions The study seeks to provide better understanding of the relationships between bone morphology and the mechanical, as well as biological environments. Furthermore, this paper provides a computational model and methodology for the numerical simulation of changes of bone structural morphology that are caused by changes of mechanical and biological

  12. Relationship of bony trabecular characteristics and age to bone mass

    International Nuclear Information System (INIS)

    Choi, Dong Hoon; Song, Young Han; Yoon, Young Nam; Lee, Wan; Lee, Byung Do

    2006-01-01

    Bony strength is dependent on bone mass and bony structure. So this study was designed to investigate the relationship between the bone mass and bony mass and bony trabecular characteristics. Study subjects were 51 females (average age 68.6 years) and 20 males (average age 66.4 years). Bony mineral density (BMD, grams/cm 2 ) of proximal femur was measured by a dual energy X-ray absorptiometry (DEXA). Regions of interest (ROIs) were selected from the digitized radiographs of proximal femur. A customized computer program processed morphologic operations (MO) of ROIs. 44 skeletal variables of MO were calculated from ROIs on the Ward's triangle and greater trochanter of femur. WHO BMD classes were predicted by MO variables of the same ROI. Classification and Regression Tree analysis was used for calculating weighted kappa values, sensitivity and specificity of MO. The discriminating factors of morphologic operation were branch point, branch point [per cm sq]. Age also played important role in distinguishing osteoporotic classes. The sensitivity of MO at Ward's triangle and Greater Trochanter was 91.8%, 65.6%, respectively. The specificity of MO was 100% at Ward's triangle and Greater Trochanter. Bony trabecular characteristics obtained using radiological bone morphometric analysis seem to be related to bone mass

  13. Finite element analysis of trabecular bone structures : a comparison of image-based meshing techniques

    NARCIS (Netherlands)

    Ulrich, D.; Rietbergen, van B.; Weinans, H.; Rüegsegger, P.

    1998-01-01

    In this study, we investigate if finite element (FE) analyses of human trabecular bone architecture based on 168 microm images can provide relevant information about the bone mechanical characteristics. Three human trabecular bone samples, one taken from the femoral head, one from the iliac crest,

  14. Complete volumetric decomposition of individual trabecular plates and rods and its morphological correlations with anisotropic elastic moduli in human trabecular bone.

    Science.gov (United States)

    Liu, X Sherry; Sajda, Paul; Saha, Punam K; Wehrli, Felix W; Bevill, Grant; Keaveny, Tony M; Guo, X Edward

    2008-02-01

    Trabecular plates and rods are important microarchitectural features in determining mechanical properties of trabecular bone. A complete volumetric decomposition of individual trabecular plates and rods was used to assess the orientation and morphology of 71 human trabecular bone samples. The ITS-based morphological analyses better characterize microarchitecture and help predict anisotropic mechanical properties of trabecular bone. Standard morphological analyses of trabecular architecture lack explicit segmentations of individual trabecular plates and rods. In this study, a complete volumetric decomposition technique was developed to segment trabecular bone microstructure into individual plates and rods. Contributions of trabecular type-associated morphological parameters to the anisotropic elastic moduli of trabecular bone were studied. Seventy-one human trabecular bone samples from the femoral neck (FN), tibia, and vertebral body (VB) were imaged using muCT or serial milling. Complete volumetric decomposition was applied to segment trabecular bone microstructure into individual plates and rods. The orientation of each individual trabecula was determined, and the axial bone volume fractions (aBV/TV), axially aligned bone volume fraction along each orthotropic axis, were correlated with the elastic moduli. The microstructural type-associated morphological parameters were derived and compared with standard morphological parameters. Their contributions to the anisotropic elastic moduli, calculated by finite element analysis (FEA), were evaluated and compared. The distribution of trabecular orientation suggested that longitudinal plates and transverse rods dominate at all three anatomic sites. aBV/TV along each axis, in general, showed a better correlation with the axial elastic modulus (r(2) = 0.95 approximately 0.99) compared with BV/TV (r(2) = 0.93 approximately 0.94). The plate-associated morphological parameters generally showed higher correlations with the

  15. Trabecular bone structure and strength - remodelling and repair

    DEFF Research Database (Denmark)

    Mosekilde, Lis; Ebbesen, Ebbe Nils; Erikstrup, Lise Tornvig

    2000-01-01

    vertical and horizontal struts reaching a certain magnitude and thereby inducing buckling under compression. 4) Microdamage and microfractures will occur - mainly in these very loaded vertical struts. The microfractures will be repaired by microcallus formation, and these calluses will later be removed...... can never be isolated in vivo, other factors need to be investigated: The interplay between the cortical shell and the trabecular network; transmission of load; the interplay between soft tissues (cartilage, connective tissue, muscle) and bone; the shock absorbing capacity of the discs...

  16. Preliminary report of cells at risk at the bone surface in trabecular bone

    International Nuclear Information System (INIS)

    Jee, W.S.S.; Wronski, T.J.; Kimmel, D.B.; Dell, R.B.; Johnson, F.

    1975-01-01

    This is a report of some early work on the cells at risk portion of the dynamic microanatomical dosimetry program of the Bone Group. The cells lining the trabecular bone of thoracic vertebral bodies from beagles aged 568, 2942, 4117, 4277, 4629, and 4801 days were characterized. Histologic and sampling experience gained in this attempt indicates that further improvements are needed

  17. The Relationship between Trabecular Bone Structure Modeling Methods and the Elastic Modulus as Calculated by FEM

    Directory of Open Access Journals (Sweden)

    Tomasz Topoliński

    2012-01-01

    Full Text Available Trabecular bone cores were collected from the femoral head at the time of surgery (hip arthroplasty. Investigated were 42 specimens, from patients with osteoporosis and coxarthrosis. The cores were scanned used computer microtomography (microCT system at an isotropic spatial resolution of 36 microns. Image stacks were converted to finite element models via a bone voxel-to-element algorithm. The apparent modulus was calculated based on the assumptions that for the elastic properties, E=10 MPa and ν=0.3. The compressive deformation as calculated by finite elements (FE analysis was 0.8%. The models were coarsened to effectively change the resolution or voxel size (from 72 microns to 288 microns or from 72 microns to 1080 microns. The aim of our study is to determine how an increase in the distance between scans changes the elastic properties as calculated by FE models. We tried to find a border value voxel size at which the module values were possible to calculate. As the voxel size increased, the mean voxel volume increased and the FEA-derived apparent modulus decreased. The slope of voxel size versus modulus relationship correlated with several architectural indices of trabecular bone.

  18. Experimentally-based multiscale model of the elastic moduli of bovine trabecular bone and its constituents

    Energy Technology Data Exchange (ETDEWEB)

    Hamed, Elham [University of Illinois at Urbana-Champaign, Department of Mechanical Science and Engineering, 1206 West Green Street, Urbana, IL 61801 (United States); Novitskaya, Ekaterina, E-mail: eevdokim@ucsd.edu [University of California, San Diego, Department of Mechanical and Aerospace Engineering, Materials Science and Engineering Program, 9500 Gilman Dr., La Jolla, CA 92093 (United States); Li, Jun; Jasiuk, Iwona [University of Illinois at Urbana-Champaign, Department of Mechanical Science and Engineering, 1206 West Green Street, Urbana, IL 61801 (United States); McKittrick, Joanna [University of California, San Diego, Department of Mechanical and Aerospace Engineering, Materials Science and Engineering Program, 9500 Gilman Dr., La Jolla, CA 92093 (United States)

    2015-09-01

    The elastic moduli of trabecular bone were modeled using an analytical multiscale approach. Trabecular bone was represented as a porous nanocomposite material with a hierarchical structure spanning from the collagen–mineral level to the trabecular architecture level. In parallel, compression testing was done on bovine femoral trabecular bone samples in two anatomical directions, parallel to the femoral neck axis and perpendicular to it, and the measured elastic moduli were compared with the corresponding theoretical results. To gain insights on the interaction of collagen and minerals at the nanoscale, bone samples were deproteinized or demineralized. After such processing, the treated samples remained as self-standing structures and were tested in compression. Micro-computed tomography was used to characterize the hierarchical structure of these three bone types and to quantify the amount of bone porosity. The obtained experimental data served as inputs to the multiscale model and guided us to represent bone as an interpenetrating composite material. Good agreement was found between the theory and experiments for the elastic moduli of the untreated, deproteinized, and demineralized trabecular bone. - Highlights: • A multiscale model was used to predict the elastic moduli of trabecular bone. • Samples included demineralized, deproteinized and untreated bone. • The model portrays bone as a porous, interpenetrating two phase composite. • The experimental elastic moduli for trabecular bone fell between theoretical bounds.

  19. Experimentally-based multiscale model of the elastic moduli of bovine trabecular bone and its constituents

    International Nuclear Information System (INIS)

    Hamed, Elham; Novitskaya, Ekaterina; Li, Jun; Jasiuk, Iwona; McKittrick, Joanna

    2015-01-01

    The elastic moduli of trabecular bone were modeled using an analytical multiscale approach. Trabecular bone was represented as a porous nanocomposite material with a hierarchical structure spanning from the collagen–mineral level to the trabecular architecture level. In parallel, compression testing was done on bovine femoral trabecular bone samples in two anatomical directions, parallel to the femoral neck axis and perpendicular to it, and the measured elastic moduli were compared with the corresponding theoretical results. To gain insights on the interaction of collagen and minerals at the nanoscale, bone samples were deproteinized or demineralized. After such processing, the treated samples remained as self-standing structures and were tested in compression. Micro-computed tomography was used to characterize the hierarchical structure of these three bone types and to quantify the amount of bone porosity. The obtained experimental data served as inputs to the multiscale model and guided us to represent bone as an interpenetrating composite material. Good agreement was found between the theory and experiments for the elastic moduli of the untreated, deproteinized, and demineralized trabecular bone. - Highlights: • A multiscale model was used to predict the elastic moduli of trabecular bone. • Samples included demineralized, deproteinized and untreated bone. • The model portrays bone as a porous, interpenetrating two phase composite. • The experimental elastic moduli for trabecular bone fell between theoretical bounds

  20. A potential mechanism for allometric trabecular bone scaling in terrestrial mammals.

    Science.gov (United States)

    Christen, Patrik; Ito, Keita; van Rietbergen, Bert

    2015-03-01

    Trabecular bone microstructural parameters, including trabecular thickness, spacing, and number, have been reported to scale with animal size with negative allometry, whereas bone volume fraction is animal size-invariant in terrestrial mammals. As for the majority of scaling patterns described in animals, its underlying mechanism is unknown. However, it has also been found that osteocyte density is inversely related to animal size, possibly adapted to metabolic rate, which shows a negative relationship as well. In addition, the signalling reach of osteocytes is limited by the extent of the lacuno-canalicular network, depending on trabecular dimensions and thus also on animal size. Here we propose animal size-dependent variations in osteocyte density and their signalling influence distance as a potential mechanism for negative allometric trabecular bone scaling in terrestrial mammals. Using an established and tested computational model of bone modelling and remodelling, we run simulations with different osteocyte densities and influence distances mimicking six terrestrial mammals covering a large range of body masses. Simulated trabecular structures revealed negative allometric scaling for trabecular thickness, spacing, and number, constant bone volume fraction, and bone turnover rates inversely related to animal size. These results are in agreement with previous observations supporting our proposal of osteocyte density and influence distance variation as a potential mechanism for negative allometric trabecular bone scaling in terrestrial mammals. The inverse relationship between bone turnover rates and animal size further indicates that trabecular bone scaling may be linked to metabolic rather than mechanical adaptations. © 2015 Anatomical Society.

  1. Age-Related Changes in Trabecular and Cortical Bone Microstructure

    Directory of Open Access Journals (Sweden)

    Huayue Chen

    2013-01-01

    Full Text Available The elderly population has substantially increased worldwide. Aging is a complex process, and the effects of aging are myriad and insidious, leading to progressive deterioration of various organs, including the skeleton. Age-related bone loss and resultant osteoporosis in the elderly population increase the risk for fractures and morbidity. Osteoporosis is one of the most common conditions associated with aging, and age is an independent risk factor for osteoporotic fractures. With the development of noninvasive imaging techniques such as computed tomography (CT, micro-CT, and high resolution peripheral quantitative CT (HR-pQCT, imaging of the bone architecture provides important information about age-related changes in bone microstructure and estimates of bone strength. In the past two decades, studies of human specimens using imaging techniques have revealed decreased bone strength in older adults compared with younger adults. The present paper addresses recently studied age-related changes in trabecular and cortical bone microstructure based primarily on HR-pQCT and micro-CT. We specifically focus on the three-dimensional microstructure of the vertebrae, femoral neck, and distal radius, which are common osteoporotic fracture sites.

  2. Age-related changes in trabecular and cortical bone microstructure.

    Science.gov (United States)

    Chen, Huayue; Zhou, Xiangrong; Fujita, Hiroshi; Onozuka, Minoru; Kubo, Kin-Ya

    2013-01-01

    The elderly population has substantially increased worldwide. Aging is a complex process, and the effects of aging are myriad and insidious, leading to progressive deterioration of various organs, including the skeleton. Age-related bone loss and resultant osteoporosis in the elderly population increase the risk for fractures and morbidity. Osteoporosis is one of the most common conditions associated with aging, and age is an independent risk factor for osteoporotic fractures. With the development of noninvasive imaging techniques such as computed tomography (CT), micro-CT, and high resolution peripheral quantitative CT (HR-pQCT), imaging of the bone architecture provides important information about age-related changes in bone microstructure and estimates of bone strength. In the past two decades, studies of human specimens using imaging techniques have revealed decreased bone strength in older adults compared with younger adults. The present paper addresses recently studied age-related changes in trabecular and cortical bone microstructure based primarily on HR-pQCT and micro-CT. We specifically focus on the three-dimensional microstructure of the vertebrae, femoral neck, and distal radius, which are common osteoporotic fracture sites.

  3. 3D Architecture of Trabecular Bone in the Pig Mandible and Femur: Inter-Trabecular Angle Distributions.

    Science.gov (United States)

    Ben-Zvi, Yehonatan; Reznikov, Natalie; Shahar, Ron; Weiner, Steve

    2017-09-01

    Cancellous bone is an intricate network of interconnected trabeculae, to which analysis of network topology can be applied. The inter-trabecular angle (ITA) analysis - an analysis of network topological parameters and regularity of network-forming nodes, was previously carried out on human proximal femora and showed that trabecular bone follows two main principles: sparsity of the network connectedness (prevalence of nodes with low connectivity in the network) and maximal space spanning (angular offset of connected elements is maximal for their number and approximates the values of geometrically symmetric shapes). These observations suggest that 3D organization of trabecular bone, irrespective of size and shape of individual elements, reflects a tradeoff between minimal metabolic cost of maintenance and maximal network stability under conditions of multidirectional loading. In this study we validate the ITA application using additional 3D structures (cork and 3D-printed metal lattices), analyze the ITA parameters in porcine proximal femora and mandibles and carry out a spatial analysis of the most common node type in the porcine mandibular condyle. The validation shows that the ITA application reliably detects designed or evolved topological parameters. The ITA parameters of porcine trabecular bones are similar to those of human bones. We demonstrate functional adaptation in the pig mandibular condyle by showing that the planar nodes with 3 edges are preferentially aligned in relation to the muscle forces that are applied to the condyle. We conclude that the ITA topological parameters are remarkable conserved, but locally do adapt to applied stresses.

  4. Bone dosimetry using synthetic images to represent trabecular bones of five regions of the human body

    Energy Technology Data Exchange (ETDEWEB)

    Lima Filho, Jose de M. [Instituto Federal de Educacao, Ciencia e Tecnologia de Pernambuco (IFPE), Recife, PE (Brazil); Vieira, Jose W. [Escola Politecnica de Pernambuco (POLI). Universidade de Pernambuco (UPE), Recife, PE (Brazil); Lima, Vanildo J. de M., E-mail: vjr@ufpe.br [Departamento de Anatomia. Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Lima, Lindeval F., E-mail: lindeval@dmat.ufrr.br [Departamento de Matematica (DMAT). Universidade Federal de Roraima (UFRR), Boa Vista, RR (Brazil); Lima, Fernando R.A., E-mail: falima@cnen.gov.br [Centro Regional de Ciencias Nucleares (CRCN/NE-CNEN-PE), Recife, PE (Brazil); Vasconcelos, Wagner E. de [Departamento de Energia Nuclear (DEN). Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2011-07-01

    One of the greatest challenges in numerical dosimetry of ionizing radiation is to estimate the absorbed dose by bone tissue in the human body. The bone tissues of greater radiosensitivity are the red bone marrow (RBM), that consist of the hematopoietic cells, located within the trabecular bones, and the bone surface cells (BSC), called osteogenic cells. The report 70 of the ICRP lists five spongiosa regions with their respective volume percent of trabecular bone: ribs (also contemplating the clavicles and sternum), spine, long bones, pelvis and skull (also contemplating mandible). The Grupo de Pesquisa em Dosimetria Numerica (GDN/CNPq) has been built exposure computational models (ECMs) based on voxel phantoms and EGSnrc Monte Carlo code. To estimate the energy deposited in the RBM and in the BSC of a phantom, the GDN/CNPq has used a method based on micro-CT images of the five trabecular regions mentioned above. These images were provided by other research institutes and were obtained from scan of bone samples of adult. Here is the greatest difficulty in reproducing this method: besides the need for bone images of real people with micrometer resolution, the distribution of bone marrow in the human body, according to ICRP 70, varies with age. This article presents some proposals of the GDN/CNPQ for replacing in the ECMs the micro-CT images by images synthesized by the computer, based on Monte Carlo sampling. (author)

  5. Bone dosimetry using synthetic images to represent trabecular bones of five regions of the human body

    International Nuclear Information System (INIS)

    Lima Filho, Jose de M.; Vieira, Jose W.; Lima, Vanildo J. de M.; Lima, Lindeval F.; Lima, Fernando R.A.; Vasconcelos, Wagner E. de

    2011-01-01

    One of the greatest challenges in numerical dosimetry of ionizing radiation is to estimate the absorbed dose by bone tissue in the human body. The bone tissues of greater radiosensitivity are the red bone marrow (RBM), that consist of the hematopoietic cells, located within the trabecular bones, and the bone surface cells (BSC), called osteogenic cells. The report 70 of the ICRP lists five spongiosa regions with their respective volume percent of trabecular bone: ribs (also contemplating the clavicles and sternum), spine, long bones, pelvis and skull (also contemplating mandible). The Grupo de Pesquisa em Dosimetria Numerica (GDN/CNPq) has been built exposure computational models (ECMs) based on voxel phantoms and EGSnrc Monte Carlo code. To estimate the energy deposited in the RBM and in the BSC of a phantom, the GDN/CNPq has used a method based on micro-CT images of the five trabecular regions mentioned above. These images were provided by other research institutes and were obtained from scan of bone samples of adult. Here is the greatest difficulty in reproducing this method: besides the need for bone images of real people with micrometer resolution, the distribution of bone marrow in the human body, according to ICRP 70, varies with age. This article presents some proposals of the GDN/CNPQ for replacing in the ECMs the micro-CT images by images synthesized by the computer, based on Monte Carlo sampling. (author)

  6. Suitability of texture features to assess changes in trabecular bone architecture

    DEFF Research Database (Denmark)

    Veenland, JF; Grashuis, JL; Weinans, H

    2002-01-01

    The purpose of this study was to determine the ability of texture features to assess changes in trabecular bone architecture as projected in radiographs. Micro-CT datasets of trabecular bone were processed to simulate different changes in architecture. Radiographs were simulated by projecting the...

  7. Contribution of mechanical unloading to trabecular bone loss following non-invasive knee injury in mice

    OpenAIRE

    Anderson, Matthew J.; Diko, Sindi; Baehr, Leslie M.; Baar, Keith; Bodine, Sue C.; Christiansen, Blaine A.

    2016-01-01

    Development of osteoarthritis commonly involves degeneration of epiphyseal trabecular bone. In previous studies, we observed 30–44% loss of epiphyseal trabecular bone (BV/TV) from the distal femur within one week following non-invasive knee injury in mice. Mechanical unloading (disuse) may contribute to this bone loss, however it is unclear to what extent the injured limb is unloaded following injury, and whether disuse can fully account for the observed magnitude of bone loss. In this study,...

  8. Genetic Dissection of Trabecular Bone Structure with Mouse Intersubspecific Consomic Strains

    Directory of Open Access Journals (Sweden)

    Taro Kataoka

    2017-10-01

    Full Text Available Trabecular bone structure has an important influence on bone strength, but little is known about its genetic regulation. To elucidate the genetic factor(s regulating trabecular bone structure, we compared the trabecular bone structures of two genetically remote mouse strains, C57BL/6J and Japanese wild mouse-derived MSM/Ms. Phenotyping by X-ray micro-CT revealed that MSM/Ms has structurally more fragile trabecular bone than C57BL/6J. Toward identification of genetic determinants for the difference in fragility of trabecular bone between the two mouse strains, we employed phenotype screening of consomic mouse strains in which each C57BL/6J chromosome is substituted by its counterpart from MSM/Ms. The results showed that many chromosomes affect trabecular bone structure, and that the consomic strain B6-Chr15MSM, carrying MSM/Ms-derived chromosome 15 (Chr15, has the lowest values for the parameters BV/TV, Tb.N, and Conn.D, and the highest values for the parameters Tb.Sp and SMI. Subsequent phenotyping of subconsomic strains for Chr15 mapped four novel trabecular bone structure-related QTL (Tbsq1-4 on mouse Chr15. These results collectively indicate that genetic regulation of trabecular bone structure is highly complex, and that even in the single Chr15, the combined action of the four Tbsqs controls the fragility of trabecular bone. Given that Tbsq4 is syntenic to human Chr 12q12-13.3, where several bone-related SNPs are assigned, further study of Tbsq4 should facilitate our understanding of the genetic regulation of bone formation in humans.

  9. MR-based trabecular bone microstructure is not altered in subjects with indolent systemic mastocytosis.

    Science.gov (United States)

    Baum, Thomas; Karampinos, Dimitrios C; Brockow, Knut; Seifert-Klauss, Vanadin; Jungmann, Pia M; Biedermann, Tilo; Rummeny, Ernst J; Bauer, Jan S; Müller, Dirk

    2015-01-01

    Subjects with indolent systemic mastocytosis (ISM) have an increased risk for osteoporosis. It has been demonstrated that trabecular bone microstructure analysis improves the prediction of bone strength beyond dual-energy X-ray absorptiometry-based bone mineral density. The purpose of this study was to obtain Magnetic Resonance (MR)-based trabecular bone microstructure parameters as advanced imaging biomarkers in subjects with ISM (n=18) and compare them with those of normal controls (n=18). Trabecular bone microstructure parameters were not significantly (P>.05) different between subjects with ISM and controls. These findings revealed important pathophysiological information about ISM-associated osteoporosis and may limit the use of trabecular bone microstructure analysis in this clinical setting. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. A study of trabecular bone strength and morphometric analysis of bone microstructure from digital radiographic image

    International Nuclear Information System (INIS)

    Han, Seung Yun; Lee, Sun Bok; Oh, Sung Ook; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul; Park, Tae Won; Kim, Jong Dae

    2003-01-01

    To evaluate the relationship between morphometric analysis of microstructure from digital radiographic image and trabecular bone strength. One hundred eleven bone specimens with 5 mm thickness were obtained from the mandibles of 5 pigs. Digital images of specimens were taken using a direct digital intraoral radiographic system. After selection of ROI(100 x 100 pixel) within the trabecular bone, mean gray level and standard deviation were obtained. Fractal dimension and the variants of morphometric analysis (trabecular area, periphery, length of skeletonized trabeculae, number of terminal point, number of branch point) were obtained from ROI. Punch sheer strength analysis was performed using Instron (model 4465, Instron Corp., USA). The loading force (loading speed 1mm/min) was applied to ROI of bone specimen by a 2 mm diameter punch. Stress-deformation curve was obtained from the punch sheer strength analysis and maximum stress, yield stress, Young's modulus were measured. Maximum stress had a negative linear correlation with mean gray level and fractal dimension significantly (p<0.05). Yield stress had a negative linear correlation with mean gray level, periphery, fractal dimension and the length of skeletonized trabeculae significantly (p<0.05). Young's modulus had a negative linear correlation with mean gray level and fractal dimension significantly (p<0.05). The strength of cancellous bone exhibited a significantly linear relationship between mean gray level, fractal dimension and morphometric analysis. The methods described above can be easily used to evaluate bone quality clinically.

  11. Effect of micro-computed tomography voxel size and segmentation method on trabecular bone microstructure measures in mice

    Directory of Open Access Journals (Sweden)

    Blaine A. Christiansen

    2016-12-01

    Full Text Available Micro-computed tomography (μCT is currently the gold standard for determining trabecular bone microstructure in small animal models. Numerous parameters associated with scanning and evaluation of μCT scans can strongly affect morphologic results obtained from bone samples. However, the effect of these parameters on specific trabecular bone outcomes is not well understood. This study investigated the effect of μCT scanning with nominal voxel sizes between 6–30 μm on trabecular bone outcomes quantified in mouse vertebral body trabecular bone. Additionally, two methods for determining a global segmentation threshold were compared: based on qualitative assessment of 2D images, or based on quantitative assessment of image histograms. It was found that nominal voxel size had a strong effect on several commonly reported trabecular bone parameters, in particular connectivity density, trabecular thickness, and bone tissue mineral density. Additionally, the two segmentation methods provided similar trabecular bone outcomes for scans with small nominal voxel sizes, but considerably different outcomes for scans with larger voxel sizes. The Qualitatively Selected segmentation method more consistently estimated trabecular bone volume fraction (BV/TV and trabecular thickness across different voxel sizes, but the Histogram segmentation method more consistently estimated trabecular number, trabecular separation, and structure model index. Altogether, these results suggest that high-resolution scans be used whenever possible to provide the most accurate estimation of trabecular bone microstructure, and that the limitations of accurately determining trabecular bone outcomes should be considered when selecting scan parameters and making conclusions about inter-group variance or between-group differences in studies of trabecular bone microstructure in small animals. Keywords: Trabecular bone, Microstructure, Micro-computed tomography, Voxel size, Resolution

  12. 3D Architecture of Trabecular Bone in the Pig Mandible and Femur: Inter-Trabecular Angle Distributions

    Directory of Open Access Journals (Sweden)

    Yehonatan Ben-Zvi

    2017-09-01

    Full Text Available Cancellous bone is an intricate network of interconnected trabeculae, to which analysis of network topology can be applied. The inter-trabecular angle (ITA analysis—an analysis of network topological parameters and regularity of network-forming nodes—was previously carried out on human proximal femora and showed that trabecular bone follows two main principles: sparsity of the network connectedness (prevalence of nodes with low connectivity in the network and maximal space spanning (angular offset of connected elements is maximal for their number and approximates the values of geometrically symmetric shapes. These observations suggest that 3D organization of trabecular bone, irrespective of size and shape of individual elements, reflects a tradeoff between minimal metabolic cost of maintenance and maximal network stability under conditions of multidirectional loading. In this study, we validate the ITA application using additional 3D structures (cork and 3D-printed metal lattices, analyze the ITA parameters in porcine proximal femora and mandibles, and carry out a spatial analysis of the most common node type in the porcine mandibular condyle. The validation shows that the ITA application reliably detects designed or evolved topological parameters. The ITA parameters of porcine trabecular bones are similar to those of human bones. We demonstrate functional adaptation in the pig mandibular condyle by showing that the planar nodes with three edges are preferentially aligned in relation to the muscle forces that are applied to the condyle. We conclude that the ITA topological parameters are remarkably conserved, but locally do adapt to applied stresses.

  13. Automated selection of trabecular bone regions in knee radiographs

    International Nuclear Information System (INIS)

    Podsiadlo, P.; Wolski, M.; Stachowiak, G. W.

    2008-01-01

    Osteoarthritic (OA) changes in knee joints can be assessed by analyzing the structure of trabecular bone (TB) in the tibia. This analysis is performed on TB regions selected manually by a human operator on x-ray images. Manual selection is time-consuming, tedious, and expensive. Even if a radiologist expert or highly trained person is available to select regions, high inter- and intraobserver variabilities are still possible. A fully automated image segmentation method was, therefore, developed to select the bone regions for numerical analyses of changes in bone structures. The newly developed method consists of image preprocessing, delineation of cortical bone plates (active shape model), and location of regions of interest (ROI). The method was trained on an independent set of 40 x-ray images. Automatically selected regions were compared to the ''gold standard'' that contains ROIs selected manually by a radiologist expert on 132 x-ray images. All images were acquired from subjects locked in a standardized standing position using a radiography rig. The size of each ROI is 12.8x12.8 mm. The automated method results showed a good agreement with the gold standard [similarity index (SI)=0.83 (medial) and 0.81 (lateral) and the offset=[-1.78, 1.27]x[-0.65,0.26] mm (medial) and [-2.15, 1.59]x[-0.58, 0.52] mm (lateral)]. Bland and Altman plots were constructed for fractal signatures, and changes of fractal dimensions (FD) to region offsets calculated between the gold standard and automatically selected regions were calculated. The plots showed a random scatter and the 95% confidence intervals were (-0.006, 0.008) and (-0.001, 0.011). The changes of FDs to region offsets were less than 0.035. Previous studies showed that differences in FDs between non-OA and OA bone regions were greater than 0.05. ROIs were also selected by a second radiologist and then evaluated. Results indicated that the newly developed method could replace a human operator and produces bone regions

  14. Trabecular bone structure correlates with hand posture and use in hominoids.

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    Zewdi J Tsegai

    Full Text Available Bone is capable of adapting during life in response to stress. Therefore, variation in locomotor and manipulative behaviours across extant hominoids may be reflected in differences in trabecular bone structure. The hand is a promising region for trabecular analysis, as it is the direct contact between the individual and the environment and joint positions at peak loading vary amongst extant hominoids. Building upon traditional volume of interest-based analyses, we apply a whole-epiphysis analytical approach using high-resolution microtomographic scans of the hominoid third metacarpal to investigate whether trabecular structure reflects differences in hand posture and loading in knuckle-walking (Gorilla, Pan, suspensory (Pongo, Hylobates and Symphalangus and manipulative (Homo taxa. Additionally, a comparative phylogenetic method was used to analyse rates of evolutionary changes in trabecular parameters. Results demonstrate that trabecular bone volume distribution and regions of greatest stiffness (i.e., Young's modulus correspond with predicted loading of the hand in each behavioural category. In suspensory and manipulative taxa, regions of high bone volume and greatest stiffness are concentrated on the palmar or distopalmar regions of the metacarpal head, whereas knuckle-walking taxa show greater bone volume and stiffness throughout the head, and particularly in the dorsal region; patterns that correspond with the highest predicted joint reaction forces. Trabecular structure in knuckle-walking taxa is characterised by high bone volume fraction and a high degree of anisotropy in contrast to the suspensory brachiators. Humans, in which the hand is used primarily for manipulation, have a low bone volume fraction and a variable degree of anisotropy. Finally, when trabecular parameters are mapped onto a molecular-based phylogeny, we show that the rates of change in trabecular structure vary across the hominoid clade. Our results support a link

  15. Assessment of spinal trabecular bone by quantitative computed tomography

    International Nuclear Information System (INIS)

    Soya, Toshio; Seto, Hikaru; Futatsuya, Ryusuke; Kamei, Tetsuya; Kakishita, Masao

    1987-01-01

    151 normal values of spinal trabecular bone mineral content (BMC) for 79 men and 72 women were studied by single energy quantitative computed tomography (QCT). The BMC value has a great relation to age. It has a maximum in the age of 20 years in men and in the age of 20 ∼ 30 years in women, and decreases gradually after these ages with a more rapid reduction in women (1.1 % per year in men and 1.6 % per year in women). In younger generation (under 50 years of age) the average value of the BMC is 180 mg/ml K 2 HPO 4 equivalent in men, 189 mg/ml in women, and in older generation, is 123 mg/ml and 112 mg/ml respectively. In the individual case, the fluctuation of inter-vertebrae (L1, L2 and L3) has large variation, therefore, to estimate one's BMC enoughly the measurement of at least three vertebrae should be done. There found no physical factor which attributes to the BMC value. It is suggested that the BMC are affected by age and sex. (author)

  16. Assessment of spinal trabecular bone by quantitative CT

    International Nuclear Information System (INIS)

    Adachi, Toshiki; Kozakura, Yoshihiro; Kato, Isamu; Yamamoto, Yoshio

    1988-01-01

    127 normal values of spinal trabecular bone mineral content (BMC) for 67 males (age range : 20 ∼ 77) and 60 females (age range : 23 ∼ 76) were studied by quantitative computed tomography (QCT). We have measured L1, L2 and L3 vertebrae, but there is no significant difference between L1, L2 and L3 BMC, so we caliculated the individual BMC from the average of the three vertebrae data. The BMC value was found to be greatly enfluenced by age. Its maximum at the age of 20 years for males and females, and decreases gradually with an increase in age with a much more reduction seen in the females. The mean value of BMC for the males was approximately 171 mg/ml K 2 HPO 4 equivalent to the 20 - 40 age range years and the females was approximately 183 mg/ml, so that by the age 70, the males were reduced by 35 % to approximately 110 mg/ml, the females were reduced by 50 % to approximately 92 mg/ml. The interrelation was analyzed by using a cubic regression study which revealed an adequate correlation (r = 0.77 in the males, r = 0.85 in the females) between BMC and age. (author)

  17. Evolution of bone disease after kidney transplantation: A prospective histomorphometric analysis of trabecular and cortical bone.

    Science.gov (United States)

    Carvalho, Catarina; Magalhães, Juliana; Pereira, Luciano; Simões-Silva, Liliana; Castro-Ferreira, Inês; Frazão, João Miguel

    2016-01-01

    Post-transplant bone disease results from multiple factors, including previous bone and mineral metabolism disturbances and effects from transplant-related medications. Bone biopsy remains the gold-standard diagnostic tool. We aimed to prospectively evaluate trabecular and cortical bone by histomorphometry after kidney transplantation. Seven patients, willing to perform follow-up bone biopsy, were included in the study. Dual-X-ray absorptiometry and trans-iliac bone biopsy were performed within the first 2 months after renal transplantation and repeated after 2-5 years of follow-up. Follow-up biopsy revealed a significant decrease in osteoblast surface/bone surface (0.91 ± 0.81 to 0.47 ± 0.12%, P = 0.036), osteoblasts number/bone surface (0.45 (0.23, 0.94) to 0.00/mm(2) , P = 0.018) and erosion surface/bone surface (3.75 ± 2.02 to 2.22 ± 1.38%, P = 0.044). A decrease in trabecular number (3.55 (1.81, 2.89) to 1.55/mm (1.24, 2.06), P = 0.018) and increase in trabecular separation (351.65 ± 135.04 to 541.79 ± 151.91 μm, P = 0.024) in follow-up biopsy suggest loss in bone quantity. We found no significant differences in cortical analysis, except a reduction in external cortical osteonal eroded surface (5.76 (2.94, 13.97) to 3.29% (0.00, 6.67), P = 0.043). Correlations between bone histomorphometric and dual-X-ray absorptiometry parameters gave inconsistent results. The results show a reduction in bone activity, suggesting increased risk of adynamic bone and loss of bone volume. Cortical bone seems less affected by post-transplant biological changes in the first years after kidney transplantation. © 2015 Asian Pacific Society of Nephrology.

  18. Spine Trabecular Bone Score as an Indicator of Bone Microarchitecture at the Peripheral Skeleton in Kidney Transplant Recipients.

    Science.gov (United States)

    Luckman, Matthew; Hans, Didier; Cortez, Natalia; Nishiyama, Kyle K; Agarawal, Sanchita; Zhang, Chengchen; Nikkel, Lucas; Iyer, Sapna; Fusaro, Maria; Guo, Edward X; McMahon, Donald J; Shane, Elizabeth; Nickolas, Thomas L

    2017-04-03

    Studies using high-resolution peripheral quantitative computed tomography showed progressive abnormalities in cortical and trabecular microarchitecture and biomechanical competence over the first year after kidney transplantation. However, high-resolution peripheral computed tomography is a research tool lacking wide availability. In contrast, the trabecular bone score is a novel and widely available tool that uses gray-scale variograms of the spine image from dual-energy x-ray absorptiometry to assess trabecular quality. There are no studies assessing whether trabecular bone score characterizes bone quality in kidney transplant recipients. Between 2009 and 2010, we conducted a study to assess changes in peripheral skeletal microarchitecture, measured by high-resolution peripheral computed tomography, during the first year after transplantation in 47 patients managed with early corticosteroid-withdrawal immunosuppression. All adult first-time transplant candidates were eligible. Patients underwent imaging with high-resolution peripheral computed tomography and dual-energy x-ray absorptiometry pretransplantation and 3, 6, and 12 months post-transplantation. We now test if, during the first year after transplantation, trabecular bone score assesses the evolution of bone microarchitecture and biomechanical competence as determined by high-resolution peripheral computed tomography. At baseline and follow-up, among the 72% and 78%, respectively, of patients having normal bone mineral density by dual-energy x-ray absorptiometry, 53% and 50%, respectively, were classified by trabecular bone score as having high fracture risk. At baseline, trabecular bone score correlated with spine, hip, and ultradistal radius bone mineral density by dual-energy x-ray absorptiometry and cortical area, density, thickness, and porosity; trabecular density, thickness, separation, and heterogeneity; and stiffness and failure load by high-resolution peripheral computed tomography

  19. The pattern of trabecular bone microarchitecture in the distal femur of typically developing children and its effect on processing of magnetic resonance images.

    Science.gov (United States)

    Modlesky, Christopher M; Whitney, Daniel G; Carter, Patrick T; Allerton, Brianne M; Kirby, Joshua T; Miller, Freeman

    2014-03-01

    Magnetic resonance imaging (MRI) is used to assess trabecular bone microarchitecture in humans; however, image processing can be labor intensive and time consuming. One aim of this study was to determine the pattern of trabecular bone microarchitecture in the distal femur of typically developing children. A second aim was to determine the proportion and location of magnetic resonance images that need to be processed to yield representative estimates of trabecular bone microarchitecture. Twenty-six high resolution magnetic resonance images were collected immediately above the growth plate in the distal femur of 6-12year-old typically developing children (n=40). Measures of trabecular bone microarchitecture [i.e., apparent trabecular bone volume to total volume (appBV/TV), trabecular number (appTb.N), trabecular thickness (appTb.Th) and trabecular separation (appTb.Sp)] in the lateral aspect of the distal femur were determined using the twenty most central images (20IM). The average values for appBV/TV, appTb.N, appTb.Th and appTb.Sp from 20IM were compared to the average values from 10 images (10IM), 5 images (5IM) and 3 images (3IM) equally dispersed throughout the total image set and one image (1IM) from the center of the total image set using linear regression analysis. The resulting mathematical models were cross-validated using the leave-one-out technique. Distance from the growth plate was strongly and inversely related to appBV/TV (r(2)=0.68, p0.05). However, there was a progressive decrease in the strength of the relationships as a smaller proportion of images were used to predict estimates from 20IM (r(2)=0.98 to 0.99 using 10IM, 0.94 to 0.96 using 5IM, 0.87 to 0.90 using 3IM and 0.66 to 0.72 using 1IM; all pimage sets agreed extremely well with estimates from 20IM. The findings indicate that partial magnetic resonance image sets can be used to provide reasonable estimates of trabecular bone microarchitecture status in the distal femur of typically

  20. Three-dimensional trabecular bone architecture of the lumbar spine in bone metastasis from prostate cancer: comparison with degenerative sclerosis

    International Nuclear Information System (INIS)

    Tamada, Tsutomu; Sone, Teruki; Imai, Shigeki; Kajihara, Yasumasa; Fukunaga, Masao; Jo, Yoshimasa

    2005-01-01

    Prostate cancer frequently metastasizes to bone, inducing osteosclerotic lesions. The objective of this study was to clarify the three-dimensional (3D) trabecular bone microstructure in bone metastasis from prostate cancer by comparison with normal and degenerative sclerotic bone lesions, using microcomputed tomography (micro-CT). A total of 32 cancellous bone samples were excised from the lumbar spine of six autopsy patients: 15 metastatic samples (one patient), eight degenerative sclerotic samples (four patients) and the rest from normal sites (three patients). The samples were serially scanned cross-sectionally by micro-CT with a pixel size of 23.20 μm, slice thickness of 18.56 μm, and image matrix of 512 x 512. Each image data set consisted of 250 consecutive slices. The volumes of interest (96 x 96 x 120 voxels) were defined in the original image sets and 3D indices of the trabecular microstructure were determined. The trabecular thickness (Tb.Th) in degenerative sclerotic lesions was significantly higher than that in normal sites, whereas no significant difference was observed in trabecular number (Tb.N). By contrast, in metastatic lesions, the Tb.N was significantly higher with increased bone volume fraction (BV/TV) than in normal sites, and no significant difference was found in Tb.Th. The characteristics of the trabecular surface in the metastatic samples showed concave structural elements with an increase in BV/TV, indicating osteolysis of the trabecular bone. In 3D reconstructed images, increased trabecular bone with an irregular surface was observed in samples from metastatic sites, which were uniformly sclerotic on soft X-ray radiographs. These results support, through 3D morphological features, the strong bone resorption effect in bone metastasis from prostate cancer. (orig.)

  1. Preliminary study of slow and fast ultrasonic waves using MR images of trabecular bone phantom

    Energy Technology Data Exchange (ETDEWEB)

    Solis-Najera, S. E., E-mail: solisnajera@ciencias.unam.mx, E-mail: angel.perez@ciencias.unam.mx, E-mail: lucia.medina@ciencias.unam.mx; Neria-Pérez, J. A., E-mail: solisnajera@ciencias.unam.mx, E-mail: angel.perez@ciencias.unam.mx, E-mail: lucia.medina@ciencias.unam.mx; Medina, L., E-mail: solisnajera@ciencias.unam.mx, E-mail: angel.perez@ciencias.unam.mx, E-mail: lucia.medina@ciencias.unam.mx [Facultad de Ciencias, Universidad Nacional Autónoma de México, México, DF 04510 (Mexico); Garipov, R., E-mail: ruslan.garipov@mrsolutions.co.uk [MR Solutions Ltd, Surrey (United Kingdom); Rodríguez, A. O., E-mail: arog@xanum.uam.mx [Departamento Ingeniería Eléctrica, Universidad Autónoma Metropolitana Iztapalapa, México, DF 09340 (Mexico)

    2014-11-07

    Cancellous bone is a complex tissue that performs physiological and biomechanical functions in all vertebrates. It is made up of trabeculae that, from a simplified structural viewpoint, can be considered as plates and beams in a hyperstatic structure that change with time leading to osteoporosis. Several methods has been developed to study the trabecular bone microstructure among them is the Biot’s model which predicts the existence of two longitudinal waves in porous media; the slow and the fast waves, that can be related to porosity of the media. This paper is focused on the experimental detection of the two Biot’s waves of a trabecular bone phantom, consisting of a trabecular network of inorganic hydroxyapatite. Experimental measurements of both waves were performed using through transmission ultrasound. Results had shown clearly that the propagation of two waves propagation is transversal to the trabecular alignment. Otherwise the waves are overlapped and a single wave seems to be propagated. To validate these results, magnetic resonance images were acquired to assess the trabecular direction, and to assure that the pulses correspond to the slow and fast waves. This approach offers a methodology for non-invasive studies of trabecular bones.

  2. Estimation of trabecular bone parameters in children from multisequence MRI using texture-based regression

    Energy Technology Data Exchange (ETDEWEB)

    Lekadir, Karim, E-mail: karim.lekadir@upf.edu; Hoogendoorn, Corné [Center for Computational Imaging and Simulation Technologies in Biomedicine, Universitat Pompeu Fabra, Barcelona 08018 (Spain); Armitage, Paul [The Academic Unit of Radiology, The University of Sheffield, Sheffield S10 2JF (United Kingdom); Whitby, Elspeth [The Academic Unit of Reproductive and Developmental Medicine, The University of Sheffield, Sheffield S10 2SF (United Kingdom); King, David [The Academic Unit of Child Health, The University of Sheffield, Sheffield S10 2TH (United Kingdom); Dimitri, Paul [The Mellanby Centre for Bone Research, The University of Sheffield, Sheffield S10 2RX (United Kingdom); Frangi, Alejandro F. [Center for Computational Imaging and Simulation Technologies in Biomedicine, The University of Sheffield, Sheffield S1 3JD (United Kingdom)

    2016-06-15

    Purpose: This paper presents a statistical approach for the prediction of trabecular bone parameters from low-resolution multisequence magnetic resonance imaging (MRI) in children, thus addressing the limitations of high-resolution modalities such as HR-pQCT, including the significant exposure of young patients to radiation and the limited applicability of such modalities to peripheral bones in vivo. Methods: A statistical predictive model is constructed from a database of MRI and HR-pQCT datasets, to relate the low-resolution MRI appearance in the cancellous bone to the trabecular parameters extracted from the high-resolution images. The description of the MRI appearance is achieved between subjects by using a collection of feature descriptors, which describe the texture properties inside the cancellous bone, and which are invariant to the geometry and size of the trabecular areas. The predictive model is built by fitting to the training data a nonlinear partial least square regression between the input MRI features and the output trabecular parameters. Results: Detailed validation based on a sample of 96 datasets shows correlations >0.7 between the trabecular parameters predicted from low-resolution multisequence MRI based on the proposed statistical model and the values extracted from high-resolution HRp-QCT. Conclusions: The obtained results indicate the promise of the proposed predictive technique for the estimation of trabecular parameters in children from multisequence MRI, thus reducing the need for high-resolution radiation-based scans for a fragile population that is under development and growth.

  3. Contribution of mechanical unloading to trabecular bone loss following non-invasive knee injury in mice.

    Science.gov (United States)

    Anderson, Matthew J; Diko, Sindi; Baehr, Leslie M; Baar, Keith; Bodine, Sue C; Christiansen, Blaine A

    2016-10-01

    Development of osteoarthritis commonly involves degeneration of epiphyseal trabecular bone. In previous studies, we observed 30-44% loss of epiphyseal trabecular bone (BV/TV) from the distal femur within 1 week following non-invasive knee injury in mice. Mechanical unloading (disuse) may contribute to this bone loss; however, it is unclear to what extent the injured limb is unloaded following injury, and whether disuse can fully account for the observed magnitude of bone loss. In this study, we investigated the contribution of mechanical unloading to trabecular bone changes observed following non-invasive knee injury in mice (female C57BL/6N). We investigated changes in gait during treadmill walking, and changes in voluntary activity level using Open Field analysis at 4, 14, 28, and 42 days post-injury. We also quantified epiphyseal trabecular bone using μCT and weighed lower-limb muscles to quantify atrophy following knee injury in both ground control and hindlimb unloaded (HLU) mice. Gait analysis revealed a slightly altered stride pattern in the injured limb, with a decreased stance phase and increased swing phase. However, Open Field analysis revealed no differences in voluntary movement between injured and sham mice at any time point. Both knee injury and HLU resulted in comparable magnitudes of trabecular bone loss; however, HLU resulted in considerably more muscle loss than knee injury, suggesting another mechanism contributing to bone loss following injury. Altogether, these data suggest that mechanical unloading likely contributes to trabecular bone loss following non-invasive knee injury, but the magnitude of this bone loss cannot be fully explained by disuse. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1680-1687, 2016. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  4. Strain rate dependency of bovine trabecular bone under impact loading at sideways fall velocity.

    Science.gov (United States)

    Enns-Bray, William S; Ferguson, Stephen J; Helgason, Benedikt

    2018-05-03

    There is currently a knowledge gap in scientific literature concerning the strain rate dependent properties of trabecular bone at intermediate strain rates. Meanwhile, strain rates between 10 and 200/s have been observed in previous dynamic finite element models of the proximal femur loaded at realistic sideways fall speeds. This study aimed to quantify the effect of strain rate (ε̇) on modulus of elasticity (E), ultimate stress (σ u ), failure energy (U f ), and minimum stress (σ m ) of trabecular bone in order to improve the biofidelity of material properties used in dynamic simulations of sideways fall loading on the hip. Cylindrical cores of trabecular bone (D = 8 mm, L gauge  = 16 mm, n = 34) from bovine proximal tibiae and distal femurs were scanned in µCT (10 µm), quantifying apparent density (ρ app ) and degree of anisotropy (DA), and subsequently impacted within a miniature drop tower. Force of impact was measured using a piezoelectric load cell (400 kHz), while displacement during compression was measured from high speed video (50,000 frames/s). Four groups, with similar density distributions, were loaded at different impact velocities (0.84, 1.33, 1.75, and 2.16 m/s) with constant kinetic energy (0.4 J) by adjusting the impact mass. The mean strain rates of each group were significantly different (p < 0.05) except for the two fastest impact speeds (p = 0.09). Non-linear regression models correlated strain rate, DA, and ρ app with ultimate stress (R 2  = 0.76), elastic modulus (R 2  = 0.63), failure energy (R 2  = 0.38), and minimum stress (R 2  = 0.57). These results indicate that previous estimates of σ u could be under predicting the mechanical properties at strain rates above 10/s. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Bone mineral measurements of subchondral and trabecular bone in healthy and osteoporotic rabbits

    International Nuclear Information System (INIS)

    Castaneda, S; Largo, R.; Marcos, M.E.; Herrero-Beaumont, G.; Calvo, E.; Rodriguez-Salvanes, F.; Diaz-Curiel, M.

    2006-01-01

    Experimental models of osteoporosis in rabbits are useful to investigate anabolic agents because this animal has a fast bone turnover with predominant remodelling over the modelling processes. For that purpose, it is necessary to characterize the densitometric values of each type of bony tissue. To determine areal bone mass measurement in the spine and in trabecular, cortical and subchondral bone of the knee in healthy and osteoporotic rabbits. Bone mineral content and bone mineral density were measured in lumbar spine, global knee, and subchondral and cortical bone of the knee with dual energy X-ray absorptiometry using a Hologic QDR-1000/W densitometer in 29 skeletally mature female healthy New Zealand rabbits. Ten rabbits underwent triplicate scans for evaluation of the effect of repositioning. Osteoporosis was experimentally induced in 15 rabbits by bilateral ovariectomy and postoperative corticosteroid treatment for 4 weeks. Identical dual energy X-ray absorptiometry (DXA) studies were performed thereafter. Mean values of bone mineral content at the lumbar spine, global knee, subchondral bone and cortical tibial metaphysis were: 1934±217 mg, 878±83 mg, 149±14 mg and 29±7.0 mg, respectively. The mean values of bone mineral density at the same regions were: 298±24 mg/cm 2 , 455±32 mg/cm 2 , 617±60 mg/cm 2 and 678±163 mg/cm 2 , respectively. (orig.)

  6. Development of a mechanical testing and loading system for trabecular bone studies for long term culture

    Directory of Open Access Journals (Sweden)

    DB Jones

    2003-03-01

    Full Text Available A highly accurate (�3% mechanical loading and measurement system combined with a trabecular bone diffusion culture-loading chamber has been developed, which provides the ability to study trabecular bone (and possibly cartilage under controlled culture and loading conditions over long periods of time. The loading device has been designed to work in two main modes, either to apply a specific compressive strain to a trabecular bone cylinder or to apply a specific force and measure the resulting deformation. Presently, precisely machined bone cylinders can be loaded at frequencies between 0.1 Hz to 50 Hz and amplitudes over 7,000�e. The system allows accurate measurement of many mechanical properties of the tissue in real time, including visco-elastic properties. This paper describes the technical components, reproducibility, precision, and the calibration procedures of the loading system. Data on long term culture and mechanical responses to different loading patterns will be published separately.

  7. Trabecular bone structural parameters evaluated using dental cone-beam computed tomography: cellular synthetic bones.

    Science.gov (United States)

    Ho, Jung-Ting; Wu, Jay; Huang, Heng-Li; Chen, Michael Y c; Fuh, Lih-Jyh; Hsu, Jui-Ting

    2013-11-09

    This study compared the adequacy of dental cone beam computed tomography (CBCT) and micro computed tomography (micro-CT) in evaluating the structural parameters of trabecular bones. The cellular synthetic bones in 4 density groups (Groups 1-4: 0.12, 0.16, 0.20, and 0.32 g/cm3) were used in this study. Each group comprised 8 experimental specimens that were approximately 1 cm3. Dental CBCT and micro-CT scans were conducted on each specimen to obtain independent measurements of the following 4 trabecular bone structural parameters: bone volume fraction (BV/TV), specific bone surface (BS/BV), trabecular thickness (Tb.Th.), and trabecular separation (Tb.Sp.). Wilcoxon signed ranks tests were used to compare the measurement variations between the dental CBCT and micro-CT scans. A Spearman analysis was conducted to calculate the correlation coefficients (r) of the dental CBCT and micro-CT measurements. Of the 4 groups, the BV/TV and Tb.Th. measured using dental CBCT were larger compared with those measured using micro-CT. By contrast, the BS/BV measured using dental CBCT was significantly less compared with those measured using micro-CT. Furthermore, in the low-density groups (Groups 1 and 2), the Tb.Sp. measured using dental CBCT was smaller compared with those measured using micro-CT. However, the Tb.Sp. measured using dental CBCT was slightly larger in the high-density groups (Groups 3 and 4) than it was in the low density groups. The correlation coefficients between the BV/TV, BS/BV, Tb.Th., and Tb.Sp. values measured using dental CBCT and micro-CT were 0.9296 (p < .001), 0.8061 (p < .001), 0.9390 (p < .001), and 0.9583 (p < .001), respectively. Although the dental CBCT and micro-CT approaches exhibited high correlations, the absolute values of BV/TV, BS/BV, Tb.Th., Tb.Sp. differed significantly between these measurements. Additional studies must be conducted to evaluate using dental CBCT in clinical practice.

  8. Effects of different loading patterns on the trabecular bone morphology of the proximal femur using adaptive bone remodeling.

    Science.gov (United States)

    Banijamali, S Mohammad Ali; Oftadeh, Ramin; Nazarian, Ara; Goebel, Ruben; Vaziri, Ashkan; Nayeb-Hashemi, Hamid

    2015-01-01

    In this study, the changes in the bone density of human femur model as a result of different loadings were investigated. The model initially consisted of a solid shell representing cortical bone encompassing a cubical network of interconnected rods representing trabecular bone. A computationally efficient program was developed that iteratively changed the structure of trabecular bone by keeping the local stress in the structure within a defined stress range. The stress was controlled by either enhancing existing beam elements or removing beams from the initial trabecular frame structure. Analyses were performed for two cases of homogenous isotropic and transversely isotropic beams.Trabecular bone structure was obtained for three load cases: walking, stair climbing and stumbling without falling. The results indicate that trabecular bone tissue material properties do not have a significant effect on the converged structure of trabecular bone. In addition, as the magnitude of the loads increase, the internal structure becomes denser in critical zones. Loading associated with the stumbling results in the highest density;whereas walking, considered as a routine daily activity, results in the least internal density in different regions. Furthermore, bone volume fraction at the critical regions of the converged structure is in good agreement with previously measured data obtained from combinations of dual X-ray absorptiometry (DXA) and computed tomography (CT). The results indicate that the converged bone architecture consisting of rods and plates are consistent with the natural bone morphology of the femur. The proposed model shows a promising means to understand the effects of different individual loading patterns on the bone density.

  9. Identification of trabecular excrescences, novel microanatomical structures, present in bone in osteoarthropathies

    Directory of Open Access Journals (Sweden)

    AM Taylor

    2012-04-01

    Full Text Available It is widely held that bone architecture is finely regulated in accordance with homeostatic requirements. Aberrant remodelling (hyperdensification and/or cyst formation in the immediately subchondral region has previously been described in bone underlying cartilage in arthropathies. The present study examined the trabecular architecture of samples of bone, initially in the severe osteoarthropathy of alkaptonuria, but subsequently in osteoarthritis using a combination of light microscopy, 3D scanning electron microscopy and quantitative backscattered electron scanning electron microscopy. We report an extraordinary and previously unrecognised bone phenotype in both disorders, including novel microanatomical structures. The underlying subchondral trabecular bone contained idiosyncratic architecture. Trabecular surfaces had numerous outgrowths that we have termed "trabecular excrescences", of which three distinct types were recognised. The first type arose from incomplete resorption of branching secondary trabeculae arising from the deposition of immature (woven bone in prior marrow space. These were characterised by very deeply scalloped surfaces and rugged edges. The second type had arisen in a similar way but been smoothed over by new bone deposition. The third type, which resembled coarse stucco, probably arises from resting surfaces that had been focally reactivated. These were poorly integrated with the prior trabecular wall. We propose that these distinctive microanatomical structures are indicative of abnormal osteoclast/osteoblast modelling in osteoarthropathies, possibly secondary to altered mechanical loading or other aberrant signalling. Identification of the mechanisms underlying the formation of trabecular excrescences will contribute to a better understanding of the role of aberrant bone remodelling in arthropathies and development of new therapeutic strategies.

  10. Effect of Low-Dose MDCT and Iterative Reconstruction on Trabecular Bone Microstructure Assessment.

    Science.gov (United States)

    Kopp, Felix K; Holzapfel, Konstantin; Baum, Thomas; Nasirudin, Radin A; Mei, Kai; Garcia, Eduardo G; Burgkart, Rainer; Rummeny, Ernst J; Kirschke, Jan S; Noël, Peter B

    2016-01-01

    We investigated the effects of low-dose multi detector computed tomography (MDCT) in combination with statistical iterative reconstruction algorithms on trabecular bone microstructure parameters. Twelve donated vertebrae were scanned with the routine radiation exposure used in our department (standard-dose) and a low-dose protocol. Reconstructions were performed with filtered backprojection (FBP) and maximum-likelihood based statistical iterative reconstruction (SIR). Trabecular bone microstructure parameters were assessed and statistically compared for each reconstruction. Moreover, fracture loads of the vertebrae were biomechanically determined and correlated to the assessed microstructure parameters. Trabecular bone microstructure parameters based on low-dose MDCT and SIR significantly correlated with vertebral bone strength. There was no significant difference between microstructure parameters calculated on low-dose SIR and standard-dose FBP images. However, the results revealed a strong dependency on the regularization strength applied during SIR. It was observed that stronger regularization might corrupt the microstructure analysis, because the trabecular structure is a very small detail that might get lost during the regularization process. As a consequence, the introduction of SIR for trabecular bone microstructure analysis requires a specific optimization of the regularization parameters. Moreover, in comparison to other approaches, superior noise-resolution trade-offs can be found with the proposed methods.

  11. Quasi-static and ratcheting properties of trabecular bone under uniaxial and cyclic compression.

    Science.gov (United States)

    Gao, Li-Lan; Wei, Chao-Lei; Zhang, Chun-Qiu; Gao, Hong; Yang, Nan; Dong, Li-Min

    2017-08-01

    The quasi-static and ratcheting properties of trabecular bone were investigated by experiments and theoretical predictions. The creep tests with different stress levels were completed and it is found that both the creep strain and creep compliance increase rapidly at first and then increase slowly as the creep time goes by. With increase of compressive stress the creep strain increases and the creep compliance decreases. The uniaxial compressive tests show that the applied stress rate makes remarkable influence on the compressive behaviors of trabecular bone. The Young's modulus of trabecular bone increases with increase of stress rate. The stress-strain hysteresis loops of trabecular bone under cyclic load change from sparse to dense with increase of number of cycles, which agrees with the change trend of ratcheting strain. The ratcheting strain rate rapidly decreases at first, and then exhibits a relatively stable and small value after 50cycles. Both the ratcheting strain and ratcheting strain rate increase with increase of stress amplitude or with decrease of stress rate. The creep model and the nonlinear viscoelastic constitutive model of trabecular bone were proposed and used to predict its creep property and rate-dependent compressive property. The results show that there are good agreements between the experimental data and predictions. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Multi-axial fatigue of trabecular bone with respect to normal walking

    CERN Document Server

    Mostakhdemin, Mohammad; Syahrom, Ardiyansyah

    2016-01-01

    This book focuses on the analysis and treatment of osteoporotic bone based on drug administration, tracking fatigue behavior and taking into consideration the mechanical interaction of implants with trabecular bone. Weak trabeculae are one of the most important clinical features that need to be addressed in order to prevent hip joint fractures.

  13. Texture analysis of trabecular bone using conventional radiographs: medical imaging and osteoporosis

    International Nuclear Information System (INIS)

    Karunanithi, R.; Panicker, T.M.R.; Paul Korath, M.; Jagadeesan, K.; Ganesan, S.

    2008-01-01

    Osteoporosis is characterized by reduced bone mass, microstructural deterioration with advancing age, and an increase in fracture risk. The accurate clinical assessment of bone strength and fracture risk is important for management of bone loss diseases such as osteoporosis risk. From a clinical point of view, microarchitecture is an interesting aspect to study and define patterns of bone alterations with aging and pathology. Microarchitecture seems to be a determinant of bone fragility independent of bone density. Moreover, bone microarchitecture seems to be important to understand the mechanisms of bone fragility independent of bone density. Moreover bone microarchitecture seems to be important to understand the mechanisms of bone fragility as well as the action of the drugs used to prevent osteoporotic fractures. In the case of osteoporosis the bone texture of the trabecular network as it appears on the plain radiographs can be quantified by applying image processing tools. Among the factors conditioning bone strength and osteoporotic fractures, bone mineral density is the most important and the best studied. Though, other factors also play a role: macroarchitecture of bones, cortical thickness, quality of bone crystal and of collagen network and trabecular microarchitecture. The microarchitecture plays a major role, and is an aspect of the definition of osteoporosis. Therefore, it would be very helpful if these alterations could be measured in addition to bone mineral density with noninvasive techniques, such as radiographs, and to assess the status of the bone by texture analysis

  14. Timing of growth hormone treatment affects trabecular bone microarchitecture and mineralization in growth hormone deficient mice.

    Science.gov (United States)

    Kristensen, Erika; Hallgrímsson, Benedikt; Morck, Douglas W; Boyd, Steven K

    2010-08-01

    Growth hormone (GH) is essential in the development of bone mass, and a growth hormone deficiency (GHD) in childhood is frequently treated with daily injections of GH. It is not clear what effect GHD and its treatment has on bone. It was hypothesized that GHD would result in impaired microarchitecture, and an early onset of treatment would result in a better recovery than late onset. Growth hormone deficient homozygous (lit/lit) mice of both sexes were divided into two treatment groups receiving daily injections of GH, starting at an early (21 days of age) or a late time point (35 days of age, corresponding to the end of puberty). A group of heterozygous mice with normal levels of growth hormone served as controls. In vivo micro-computed tomography scans of the fourth lumbar vertebra were obtained at five time points between 21 and 60 days of age, and trabecular morphology and volumetric BMD were analyzed to determine the effects of GH on bone microarchitecture. Early GH treatment led to significant improvements in bone volume ratio (p=0.006), tissue mineral density (p=0.005), and structure model index (p=0.004) by the study endpoint (day 60), with no detected change in trabecular thickness. Trabecular number increased and trabecular separation decreased in GHD mice regardless of treatment compared to heterozygous mice. This suggests fundamental differences in the structure of trabecular bone in GHD and GH treated mice, reflected by an increased number of thinner trabeculae in these mice compared to heterozygous controls. There were no significant differences between the late treatment group and GHD mice except for connectivity density. Taken together, these results indicate that bone responds to GH treatment initiated before puberty but not to treatment commencing post-puberty, and that GH treatment does not rescue the structure of trabecular bone to that of heterozygous controls. Copyright 2010 Elsevier Inc. All rights reserved.

  15. Measurement of Trabecular Bone Parameters in Porcine Vertebral Bodies Using Multidetector CT: Evaluation of Reproducibility of 3-Dimensional CT Histomorphometry

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Hwan; Goo, Jin Mo [Dept. of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of); Moon Kyung Chul [Dept. of Pathology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of); An, Sang Bu [Dept. of radiology, National Cancer Center, Goyang (Korea, Republic of); Kim, Kwang Gi [Dept. of Biomedical Engineering, Division of Basic and Applied Sciences, National Cancer Center, Goyang (Korea, Republic of)

    2011-05-15

    To evaluate the reproducibility of 3-dimensional histomorphometry for the microarchitecture analysis of trabecular bone parameters using multidetector computed tomography (MDCT). Thirty-six specimens from porcine vertebral bodies were imaged five times with a 64- detector row MDCT system using the same scan protocols. Locations of the specimens were nearly identical through the scans. Three-dimensional structural parameters of trabecular bone were derived from the five data sets using image analyzing software. The features measured by the analysis programs were trabecular bone volume, trabecular bone volume/tissue volume, trabecular thickness, trabecular separation, trabecular number, trabecular bone pattern factor, structural model index. The structural trabecular parameters showed excellent reproducibility through repeated scanning. Intraclass correlation coefficients of all seven structural parameters were in the range of 0.998 to 1.000. Coefficients of variation of the six structural parameters, excluding structural model index, were not over 1.6%. The measurement of the trabecular structural parameters using multidetector CT and three-dimensional histomophometry analysis program was validated and showed excellent reproducibility. This method could be used as a noninvasive and easily available test in a clinical setting.

  16. A theoretical framework for strain-related trabecular bone maintenance and adaptation.

    Science.gov (United States)

    Ruimerman, R; Hilbers, P; van Rietbergen, B; Huiskes, R

    2005-04-01

    It is assumed that density and morphology of trabecular bone is partially controlled by mechanical forces. How these effects are expressed in the local metabolic functions of osteoclast resorption and osteoblast formation is not known. In order to investigate possible mechano-biological pathways for these mechanisms we have proposed a mathematical theory (Nature 405 (2000) 704). This theory is based on hypothetical osteocyte stimulation of osteoblast bone formation, as an effect of elevated strain in the bone matrix, and a role for microcracks and disuse in promoting osteoclast resorption. Applied in a 2-D Finite Element Analysis model, the theory explained the formation of trabecular patterns. In this article we present a 3-D FEA model based on the same theory and investigated its potential morphological predictability of metabolic reactions to mechanical loads. The computations simulated the development of trabecular morphological details during growth, relative to measurements in growing pigs, reasonably realistic. They confirmed that the proposed mechanisms also inherently lead to optimal stress transfer. Alternative loading directions produced new trabecular orientations. Reduction of load reduced trabecular thickness, connectivity and mass in the simulation, as is seen in disuse osteoporosis. Simulating the effects of estrogen deficiency through increased osteoclast resorption frequencies produced osteoporotic morphologies as well, as seen in post-menopausal osteoporosis. We conclude that the theory provides a suitable computational framework to investigate hypothetical relationships between bone loading and metabolic expressions.

  17. Fractal analysis of mandibular trabecular bone: optimal tile sizes for the tile counting method.

    Science.gov (United States)

    Huh, Kyung-Hoe; Baik, Jee-Seon; Yi, Won-Jin; Heo, Min-Suk; Lee, Sam-Sun; Choi, Soon-Chul; Lee, Sun-Bok; Lee, Seung-Pyo

    2011-06-01

    This study was performed to determine the optimal tile size for the fractal dimension of the mandibular trabecular bone using a tile counting method. Digital intraoral radiographic images were obtained at the mandibular angle, molar, premolar, and incisor regions of 29 human dry mandibles. After preprocessing, the parameters representing morphometric characteristics of the trabecular bone were calculated. The fractal dimensions of the processed images were analyzed in various tile sizes by the tile counting method. The optimal range of tile size was 0.132 mm to 0.396 mm for the fractal dimension using the tile counting method. The sizes were closely related to the morphometric parameters. The fractal dimension of mandibular trabecular bone, as calculated with the tile counting method, can be best characterized with a range of tile sizes from 0.132 to 0.396 mm.

  18. The relationship between dental implant stability and trabecular bone structure using cone-beam computed tomography

    Science.gov (United States)

    2016-01-01

    Purpose The objective of this study was to investigate the relationships between primary implant stability as measured by impact response frequency and the structural parameters of trabecular bone using cone-beam computed tomography(CBCT), excluding the effect of cortical bone thickness. Methods We measured the impact response of a dental implant placed into swine bone specimens composed of only trabecular bone without the cortical bone layer using an inductive sensor. The peak frequency of the impact response spectrum was determined as an implant stability criterion (SPF). The 3D microstructural parameters were calculated from CT images of the bone specimens obtained using both micro-CT and CBCT. Results SPF had significant positive correlations with trabecular bone structural parameters (BV/TV, BV, BS, BSD, Tb.Th, Tb.N, FD, and BS/BV) (Pmicro-CT and CBCT (Pimplant stability prediction by combining BV/TV and SMI in the stepwise forward regression analysis. Bone with high volume density and low surface density shows high implant stability. Well-connected thick bone with small marrow spaces also shows high implant stability. The combination of bone density and architectural parameters measured using CBCT can predict the implant stability more accurately than the density alone in clinical diagnoses. PMID:27127692

  19. Bone mineral density and trabecular bone tissue quality in obese men

    Directory of Open Access Journals (Sweden)

    V.V. Povoroznyuk

    2017-02-01

    Full Text Available Obesity and osteoporosis are the two metabolic dise­ases with increased prevalence over last decades and a strong impact on the global morbidity and mortality have gained a status of major health threats worldwide. There is evidence that the higher body mass index (BMI values are associated with greater bone mineral density (BMD resulting in a site-specific protective effect for fragility fractures. On the other hand, higher BMI values increases incidence of falls and is associated with worse fractures consolidation. However, trabecular bone score (TBS indirectly explores bone quali­ty, independently of BMD. The aim of the study was to determine the connection between the BMD and TBS parameters in Ukrainian men suffering from obesity. Methods. We examined 396 men aged 40–89 years, by the BMI all the subjects were divided into 2 groups: Group A — with obesity and BMI ≥ 30 kg/m2 (n = 129 and Group B — without obesity and BMI < 30 kg/m2 (n = 267. The BMD of total body, lumbar spine at the site L1–L4, femur and forearm were measured by DXA (Prodigy, GEHC Lunar, Madison, WI, USA. The TBS of L1–L4 was assessed by means of TBS iNsight (Med-Imaps, Pessac, France. Results. In general, obese men had a significantly higher BMD of lumbar spine, femoral neck, total body and ultradistal forearm (p < 0.001 in comparison with men without obesity. The TBS of L1–L4 was significantly lower in obese men compared to non-obese men (p < 0.001. The significant positive correlation between the fat mass and the BMD at different sites was observed. The correlation between the fat mass and TBS of L1–L4 was also significant, but negative. Conclusions. Obesity negatively affects the quality of trabecular bone, while bone mineral density was significantly higher.

  20. Diagnosis of osteoarthritis and prognosis of tibial cartilage loss by quantification of tibia trabecular bone from MRI

    DEFF Research Database (Denmark)

    Marques, Joselene; Genant, Harry K.; Lillholm, Martin

    2013-01-01

    loss were assessed by a segmentation process. Aiming to quantify and potentially capture the structure of the trabecular bone anatomy, a machine learning approach used a set of texture features for training a classifier to recognize the trabecular bone of a knee with radiographic osteoarthritis. Using...

  1. Distributional variations in trabecular architecture of the mandibular bone: an in vivo micro-CT analysis in rats.

    Directory of Open Access Journals (Sweden)

    Zhongshuang Liu

    Full Text Available To evaluate the effect of trabecular thickness and trabecular separation on modulating the trabecular architecture of the mandibular bone in ovariectomized rats.Fourteen 12-week-old adult female Wistar rats were divided into an ovariectomy group (OVX and a sham-ovariectomy group (sham. Five months after the surgery, the mandibles from 14 rats (seven OVX and seven sham were analyzed by micro-CT. Images of inter-radicular alveolar bone of the mandibular first molars underwent three-dimensional reconstruction and were analyzed.Compared to the sham group, trabecular thickness in OVX alveolar bone decreased by 27% (P = 0.012, but trabecular separation in OVX alveolar bone increased by 59% (P = 0.005. A thickness and separation map showed that trabeculae of less than 100 μm increased by 46%, whereas trabeculae of more than 200 μm decreased by more than 40% in the OVX group compared to those in the sham group. Furthermore, the OVX separation of those trabecular of more than 200 μm was 65% higher compared to the sham group. Bone mineral density (P = 0.028 and bone volume fraction (p = 0.001 were also significantly decreased in the OVX group compared to the sham group.Ovariectomy-induced bone loss in mandibular bone may be related to the distributional variations in trabecular thickness and separation which profoundly impact the modulation of the trabecular architecture.

  2. Relationships between age and microarchitectural descriptors of iliac trabecular bone determined by microCT.

    Science.gov (United States)

    Deguette, C; Ramond-Roquin, A; Rougé-Maillart, C

    2017-06-01

    Estimation of age at death is a major issue in anthropology. The main anthropological histological methods propose studying the architecture of cortical bone. In bone histomorphometry, researches on metabolic bone diseases have provided normative tables for trabecular bone volume (BV/TV) according to age and gender of individuals on trans-iliac bone biopsies. We have used microCT, a non-destructive tool for measuring bone volume and trabecular descriptors to compare the French tables to a series of forensic anthropological population and if the two iliac bones could be used interchangeably. Coxal bone of a personal forensic collection whose age and gender were known (DNA identification) were used. Bone samples, centered on the same area than bone biopsy. MicroCT (pixel size: 36μm) was used to measure BV/TV and morphometric trabecular parameters of microarchitecture. An adjusted Z-score was calculated for BV/TV to compare with normative tables and a right/left comparison of trabecular parameters was provided. Twenty-seven iliac bones, which 20 forming 10 complete pelvises, aged between 24 and 73y.o. (average of 47.7 y.o.) were used. All adjusted Z-score were within normal values. There was a strong positive correlation between right and left sides for Tb.Th, Tb.N and Tb.Sp, but an insignificant correlation was obtained for BV/TV. Normative tables between age and BV/TV are valid and therefore usable in anthropology. They may represent an alternative to determine the age at death. Nevertheless, it requires a precise technique that could be a drawback in current practice. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  3. Vertebral body bone strength: the contribution of individual trabecular element morphology.

    Science.gov (United States)

    Parkinson, I H; Badiei, A; Stauber, M; Codrington, J; Müller, R; Fazzalari, N L

    2012-07-01

    Although the amount of bone explains the largest amount of variability in bone strength, there is still a significant proportion unaccounted for. The morphology of individual bone trabeculae explains a further proportion of the variability in bone strength and bone elements that contribute to bone strength depending on the direction of loading. Micro-CT imaging enables measurement of bone microarchitecture and subsequently mechanical strength of the same sample. It is possible using micro-CT data to perform morphometric analysis on individual rod and plate bone trabeculae using a volumetric spatial decomposition algorithm and hence determine their contribution to bone strength. Twelve pairs of vertebral bodies (T12/L1 or L4/L5) were harvested from human cadavers, and bone cubes (10 × 10 × 10 mm) were obtained. After micro-CT imaging, a volumetric spatial decomposition algorithm was applied, and measures of individual trabecular elements were obtained. Bone strength was measured in compression, where one bone specimen from each vertebral segment was tested supero-inferiorly (SI) and the paired specimen was tested antero-posteriorly (AP). Bone volume fraction was the strongest individual determinant of SI strength (r(2) = 0.77, p body bone architecture into its constituent morphological elements shows that trabecular element morphology has specific functional roles to assist in maintaining skeletal integrity.

  4. Two and three-dimensional morphometric analysis of trabecular bone using X-ray microtomography (μCT)

    International Nuclear Information System (INIS)

    Silva, Alessandro Marcio Hakme da; Silva, Orivaldo Lopes da; Silva Junior, Nelson Ferreira da; Alves, Jose Marcos

    2014-01-01

    Introduction: trabecular bones have a porous microstructure and can be modeled as linear elastic solids, heterogeneous and anisotropic. In the literature, few investigations have compared the two- dimensional (2D) and three-dimensional (3D) morphometric analyses of cancellous bone. Methods: In this investigation eighteen cylindrical samples of cancellous bone (10 mm of diameter and 20 mm of height) were obtained from six bovine head femurs, with similar values for the weight and age, of the same race and gender. The samples were harvested and freeze at - 20 °C before carrying out the micro CT analysis. The CT-Analyzer software was used to measure in three directions (superior-inferior, lateral-medial and anterior-posterior) parameters such as trabecular thickness, trabecular separation, trabecular number and the eigenvalues of the fabric tensor (M). Results: the Comparison of 2D and 3D analyses for the parameters: 2D (plate model) trabecular thickness, trabecular separation and trabecular number were statistically different (p = 0) showing that measurements are not similar to the 3D ones. However, 2D (rod model) trabecular thickness and 3D trabecular thickness measurements presented no significant difference (p = 0.26). The eigenvalues show that the bovine trabecular microstructure has a tendency to transversally isotropic symmetry. Discussion: The method proved to be quite interesting for the characterization of the bone structure through 3D measurements of trabecular bone morphometric parameters in the three possible directions of loading. The results show that x-ray microtomography (μCT) is a technique of great potential for characterization and generating bone quality parameters for the diagnosis of bone metabolism diseases. (author)

  5. Two and three-dimensional morphometric analysis of trabecular bone using X-ray microtomography (μCT)

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Alessandro Marcio Hakme da; Silva, Orivaldo Lopes da; Silva Junior, Nelson Ferreira da, E-mail: alhakme@sc.usp.br [Universidade de Sao Paulo (EESC/FMRP/IQSC/USP), Sao Carlos, SP (Brazil); Alves, Jose Marcos [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Escola de Engenharia. Departamento de Engenharia Eletrica e Computacao

    2014-07-01

    Introduction: trabecular bones have a porous microstructure and can be modeled as linear elastic solids, heterogeneous and anisotropic. In the literature, few investigations have compared the two- dimensional (2D) and three-dimensional (3D) morphometric analyses of cancellous bone. Methods: In this investigation eighteen cylindrical samples of cancellous bone (10 mm of diameter and 20 mm of height) were obtained from six bovine head femurs, with similar values for the weight and age, of the same race and gender. The samples were harvested and freeze at - 20 °C before carrying out the micro CT analysis. The CT-Analyzer software was used to measure in three directions (superior-inferior, lateral-medial and anterior-posterior) parameters such as trabecular thickness, trabecular separation, trabecular number and the eigenvalues of the fabric tensor (M). Results: the Comparison of 2D and 3D analyses for the parameters: 2D (plate model) trabecular thickness, trabecular separation and trabecular number were statistically different (p = 0) showing that measurements are not similar to the 3D ones. However, 2D (rod model) trabecular thickness and 3D trabecular thickness measurements presented no significant difference (p = 0.26). The eigenvalues show that the bovine trabecular microstructure has a tendency to transversally isotropic symmetry. Discussion: The method proved to be quite interesting for the characterization of the bone structure through 3D measurements of trabecular bone morphometric parameters in the three possible directions of loading. The results show that x-ray microtomography (μCT) is a technique of great potential for characterization and generating bone quality parameters for the diagnosis of bone metabolism diseases. (author)

  6. Prediction of progression of radiographic knee osteoarthritis using tibial trabecular bone texture

    DEFF Research Database (Denmark)

    Woloszynski, T; Podsiadlo, P; Stachowiak, G W

    2012-01-01

    OBJECTIVE.: To develop a system for prediction of progression of radiographic knee osteoarthritis (OA) using tibial trabecular bone (TB) texture. METHODS.: We studied 203 knees with (n=68) or without (n=135) radiographic tibiofemoral OA in 105 subjects (90 men, 15 women, mean age 54 years) who ha...

  7. A theoretical framework for strain-related trabecular bone maintenance and adaptation

    NARCIS (Netherlands)

    Ruimerman, R.; Hilbers, P.A.J.; Rietbergen, van B.; Huiskes, R.

    2005-01-01

    It is assumed that density and morphology of trabecular bone is partially controlled by mechanical forces. How these effects are expressed in the local metabolic functions of osteoclast resorption and osteoblast formation is not known. In order to investigate possible mechano-biological pathways for

  8. Neocellularization and neovascularization of nanosized bioactive glass-coated decellularized trabecular bone scaffolds

    KAUST Repository

    Gerhardt, Lutz Christian; Widdows, Kate L.; Erol, Melek M.; Nandakumar, Anandkumar; Roqan, Iman S.; Ansari, Tahera I.; Boccaccini, Aldo R.

    2012-01-01

    amount of vascular endothelial growth factor (VEGF) secreted by human fibroblasts grown on n-BG coatings (0-1.245 mg/cm 2), decellularized trabecular bone samples (porosity: 43-81%) were coated with n-BG particles. Grown on n-BG particles at a coating

  9. Direct mechanics assessment of elastic symmetries and properties of trabecular bone architecture

    NARCIS (Netherlands)

    Rietbergen, van B.; Odgaard, A.; Kabel, J.; Huiskes, H.W.J.

    1996-01-01

    A method is presented to find orthotropic elastic symmetries and constants directly from the elastic coefficients in the overall stiffness matrix of trabecular bone test specimens. Contrary to earlier developed techniques, this method does not require pure orthotropic behavior or additional fabric

  10. Structure model index does not measure rods and plates in trabecular bone

    Directory of Open Access Journals (Sweden)

    Phil L Salmon

    2015-10-01

    Full Text Available Structure model index (SMI is widely used to measure rods and plates in trabecular bone. It exploits the change in surface curvature that occurs as a structure varies from spherical (SMI = 4, to cylindrical (SMI = 3 to planar (SMI = 0. The most important assumption underlying SMI is that the entire bone surface is convex and that the curvature differential is positive at all points on the surface. The intricate connections within the trabecular continuum suggest that a high proportion of the surface could be concave, violating the assumption of convexity and producing regions of negative differential. We implemented SMI in the BoneJ plugin and included the ability to measure the amounts of surface that increased or decreased in area after surface mesh dilation, and the ability to visualize concave and convex regions. We measured SMI and its positive (SMI+ and negative (SMI- components, bone volume fraction (BV/TV, the fraction of the surface that is concave (CF, and mean ellipsoid factor (EF in trabecular bone using 38 X-ray microtomography (XMT images from a rat ovariectomy model of sex steroid rescue of bone loss, and 169 XMT images from a broad selection of 87 species' femora (mammals, birds, and a crocodile. We simulated bone resorption by eroding an image of elephant trabeculae and recording SMI and BV/TV at each erosion step. Up to 70%, and rarely less than 20%, of the trabecular surface is concave (CF 0.155 – 0.700. SMI is unavoidably influenced by aberrations from SMI-, which is strongly correlated with BV/TV and CF. The plate-to-rod transition in bone loss is an erroneous observation resulting from SMI's close and artefactual relationship with BV/TV. SMI cannot discern between the distinctive trabecular geometries typical of mammalian and avian bone, whereas EF clearly detects birds' more plate-like trabeculae. EF is free from confounding relationships with BV/TV and CF. SMI results reported in the literature should be treated with

  11. Multi-Elemental Profiling of Tibial and Maxillary Trabecular Bone in Ovariectomised Rats

    Directory of Open Access Journals (Sweden)

    Pingping Han

    2016-06-01

    Full Text Available Atomic minerals are the smallest components of bone and the content of Ca, being the most abundant mineral in bone, correlates strongly with the risk of osteoporosis. Postmenopausal women have a far greater risk of suffering from OP due to low Ca concentrations in their bones and this is associated with low bone mass and higher bone fracture rates. However, bone strength is determined not only by Ca level, but also a number of metallic and non-metallic elements in bone. Thus, in this study, the difference of metallic and non-metallic elements in ovariectomy-induced osteoporosis tibial and maxillary trabecular bone was investigated in comparison with sham operated normal bone by laser ablation inductively-coupled plasma mass spectrometry using a rat model. The results demonstrated that the average concentrations of 25Mg, 28Si, 39K, 47Ti, 56Fe, 59Co, 77Se, 88Sr, 137Ba, and 208Pb were generally higher in tibia than those in maxilla. Compared with the sham group, Ovariectomy induced more significant changes of these elements in tibia than maxilla, indicating tibial trabecular bones are more sensitive to changes of circulating estrogen. In addition, the concentrations of 28Si, 77Se, 208Pb, and Ca/P ratios were higher in tibia and maxilla in ovariectomised rats than those in normal bone at all time-points. The present study indicates that ovariectomy could significantly impact the element distribution and concentrations between tibia and maxilla.

  12. Total water, phosphorus relaxation and inter-atomic organic to inorganic interface are new determinants of trabecular bone integrity.

    Directory of Open Access Journals (Sweden)

    Ratan Kumar Rai

    Full Text Available Bone is the living composite biomaterial having unique structural property. Presently, there is a considerable gap in our understanding of bone structure and composition in the native state, particularly with respect to the trabecular bone, which is metabolically more active than cortical bones, and is readily lost in post-menopausal osteoporosis. We used solid-state nuclear magnetic resonance (NMR to compare trabecular bone structure and composition in the native state between normal, bone loss and bone restoration conditions in rat. Trabecular osteopenia was induced by lactation as well as prolonged estrogen deficiency (bilateral ovariectomy, Ovx. Ovx rats with established osteopenia were administered with PTH (parathyroid hormone, trabecular restoration group, and restoration was allowed to become comparable to sham Ovx (control group using bone mineral density (BMD and µCT determinants. We used a technique combining (1H NMR spectroscopy with (31P and (13C to measure various NMR parameters described below. Our results revealed that trabecular bones had diminished total water content, inorganic phosphorus NMR relaxation time (T1 and space between the collagen and inorganic phosphorus in the osteopenic groups compared to control, and these changes were significantly reversed in the bone restoration group. Remarkably, bound water was decreased in both osteopenic and bone restoration groups compared to control. Total water and T1 correlated strongly with trabecular bone density, volume, thickness, connectivity, spacing and resistance to compression. Bound water did not correlate with any of the microarchitectural and compression parameters. We conclude that total water, T1 and atomic space between the crystal and organic surface are altered in the trabecular bones of osteopenic rats, and PTH reverses these parameters. Furthermore, from these data, it appears that total water and T1 could serve as trabecular surrogates of micro-architecture and

  13. Troglitazone treatment increases bone marrow adipose tissue volume but does not affect trabecular bone volume in mice

    DEFF Research Database (Denmark)

    Erikstrup, Lise Tornvig; Mosekilde, Leif; Justesen, J

    2001-01-01

    proliferator activated receptor-gamma (PPARgamma). Histomorphometric analysis of proximal tibia was performed in order to quantitate the amount of trabecular bone volume per total volume (BV/TV %), adipose tissue volume per total volume (AV/TV %), and hematopoietic marrow volume per total volume (HV......Aging is associated with decreased trabecular bone mass and increased adipocyte formation in bone marrow. As osteoblasts and adipocytes share common precursor cells present in the bone marrow stroma, it has been proposed that an inverse relationship exists between adipocyte and osteoblast....../TV %) using the point-counting technique. Bone size did not differ between the two groups. In troglitazone-treated mice, AV/TV was significantly higher than in control mice (4.7+/-2.1% vs. 0.2+/-0.3%, respectively, mean +/- SD, P

  14. Computational modelling of the mechanics of trabecular bone and marrow using fluid structure interaction techniques.

    Science.gov (United States)

    Birmingham, E; Grogan, J A; Niebur, G L; McNamara, L M; McHugh, P E

    2013-04-01

    Bone marrow found within the porous structure of trabecular bone provides a specialized environment for numerous cell types, including mesenchymal stem cells (MSCs). Studies have sought to characterize the mechanical environment imposed on MSCs, however, a particular challenge is that marrow displays the characteristics of a fluid, while surrounded by bone that is subject to deformation, and previous experimental and computational studies have been unable to fully capture the resulting complex mechanical environment. The objective of this study was to develop a fluid structure interaction (FSI) model of trabecular bone and marrow to predict the mechanical environment of MSCs in vivo and to examine how this environment changes during osteoporosis. An idealized repeating unit was used to compare FSI techniques to a computational fluid dynamics only approach. These techniques were used to determine the effect of lower bone mass and different marrow viscosities, representative of osteoporosis, on the shear stress generated within bone marrow. Results report that shear stresses generated within bone marrow under physiological loading conditions are within the range known to stimulate a mechanobiological response in MSCs in vitro. Additionally, lower bone mass leads to an increase in the shear stress generated within the marrow, while a decrease in bone marrow viscosity reduces this generated shear stress.

  15. Micro-CT characterization of human trabecular bone in osteogenesis imperfecta

    Science.gov (United States)

    Jameson, John; Albert, Carolyne; Smith, Peter; Molthen, Robert; Harris, Gerald

    2011-03-01

    Osteogenesis imperfecta (OI) is a genetic syndrome affecting collagen synthesis and assembly. Its symptoms vary widely but commonly include bone fragility, reduced stature, and bone deformity. Because of the small size and paucity of human specimens, there is a lack of biomechanical data for OI bone. Most literature has focused on histomorphometric analyses, which rely on assumptions to extrapolate 3-D properties. In this study, a micro-computed tomography (μCT) system was used to directly measure structural and mineral properties in pediatric OI bone collected during routine surgical procedures. Surface renderings suggested a poorly organized, plate-like orientation. Patients with a history of bone-augmenting drugs exhibited increased bone volume fraction (BV/TV), trabecular number (Tb.N), and connectivity density (Eu.Conn.D). The latter two parameters appeared to be related to OI severity. Structural results were consistently higher than those reported in a previous histomorphometric study, but these differences can be attributed to factors such as specimen collection site, drug therapy, and assumptions associated with histomorphometry. Mineral testing revealed strong correlations with several structural parameters, highlighting the importance of a dual approach in trabecular bone testing. This study reports some of the first quantitative μCT data of human OI bone, and it suggests compelling possibilities for the future of OI bone assessment.

  16. An expression relating breaking stress and density of trabecular bone

    DEFF Research Database (Denmark)

    Rajapakse, C.S.; Thomsen, J.S.; Ortiz, J.S.E.

    2004-01-01

    Bone mineral density (BMD) is the principal diagnostic tool used in clinical settings to diagnose and monitor osteoporosis. Experimental studies on ex vivo bone samples from multiple skeletal locations have been used to propose that their breaking stress bears a power-law relationship to volumetric...

  17. Grizzly bears (Ursus arctos horribilis) and black bears (Ursus americanus) prevent trabecular bone loss during disuse (hibernation).

    Science.gov (United States)

    McGee-Lawrence, Meghan E; Wojda, Samantha J; Barlow, Lindsay N; Drummer, Thomas D; Castillo, Alesha B; Kennedy, Oran; Condon, Keith W; Auger, Janene; Black, Hal L; Nelson, O Lynne; Robbins, Charles T; Donahue, Seth W

    2009-12-01

    Disuse typically causes an imbalance in bone formation and bone resorption, leading to losses of cortical and trabecular bone. In contrast, bears maintain balanced intracortical remodeling and prevent cortical bone loss during disuse (hibernation). Trabecular bone, however, is more detrimentally affected than cortical bone in other animal models of disuse. Here we investigated the effects of hibernation on bone remodeling, architectural properties, and mineral density of grizzly bear (Ursus arctos horribilis) and black bear (Ursus americanus) trabecular bone in several skeletal locations. There were no differences in bone volume fraction or tissue mineral density between hibernating and active bears or between pre- and post-hibernation bears in the ilium, distal femur, or calcaneus. Though indices of cellular activity level (mineral apposition rate, osteoid thickness) decreased, trabecular bone resorption and formation indices remained balanced in hibernating grizzly bears. These data suggest that bears prevent bone loss during disuse by maintaining a balance between bone formation and bone resorption, which consequently preserves bone structure and strength. Further investigation of bone metabolism in hibernating bears may lead to the translation of mechanisms preventing disuse-induced bone loss in bears into novel treatments for osteoporosis.

  18. Acute hypothalamic suppression significantly affects trabecular bone but not cortical bone following recovery and ovariectomy surgery in a rat model

    Directory of Open Access Journals (Sweden)

    Vanessa R. Yingling

    2016-01-01

    Full Text Available Background. Osteoporosis is “a pediatric disease with geriatric consequences.” Bone morphology and tissue quality co-adapt during ontogeny for sufficient bone stiffness. Altered bone morphology from hypothalamic amenorrhea, a risk factor for low bone mass in women, may affect bone strength later in life. Our purpose was to determine if altered morphology following hypothalamic suppression during development affects cortical bone strength and trabecular bone volume (BV/TV at maturity.Methods. Female rats (25 days old were assigned to a control (C group (n = 45 that received saline injections (.2 cc or an experimental group (GnRH-a (n = 45 that received gonadotropin releasing hormone antagonist injections (.24 mg per dose for 25 days. Fifteen animals from each group were sacrificed immediately after the injection protocol at Day 50 (C, GnRH-a. The remaining animals recovered for 135 days and a subset of each group was sacrificed at Day 185 ((C-R (n = 15 and (G-R (n = 15. The remaining animals had an ovariectomy surgery (OVX at 185 days of age and were sacrificed 40 days later (C-OVX (n = 15 and (G-OVX (n = 15. After sacrifice femurs were mechanically tested and scanned using micro CT. Serum C-terminal telopeptides (CTX and insulin-like growth factor 1 (IGF-1 were measured. Two-way ANOVA (2 groups (GnRH-a and Control X 3 time points (Injection Protocol, Recovery, post-OVX was computed.Results. GnRH-a injections suppressed uterine weights (72% and increased CTX levels by 59%. Bone stiffness was greater in the GnRH-a groups compared to C. Ash content and cortical bone area were similar between groups at all time points. Polar moment of inertia, a measure of bone architecture, was 15% larger in the GnRH-a group and remained larger than C (19% following recovery. Both the polar moment of inertia and cortical area increased linearly with the increases in body weight. Following the injection protocol, trabecular BV/TV was 31% lower in the Gn

  19. Synergistic effect of parathyroid hormone and growth hormone on trabecular and cortical bone formation in hypophysectomized rats.

    Science.gov (United States)

    Guevarra, Maria Sarah N; Yeh, James K; Castro Magana, Mariano; Aloia, John F

    2010-01-01

    Growth hormone (GH) deficiency in pediatric patients results in short stature and osteopenia. We postulated that the GH and parathyroid hormone (PTH) combination would result in improvement in bone growth and bone formation. Forty hypophysectomized female rats at age 8 weeks were divided into hypophysectomy (HX), HX + PTH (62.5 microg/kg, s.c. daily), HX + GH (3.33 mg/kg, s.c. daily), and HX + PTH + GH for a 4-week study. GH increased body weight, bone growth, bone mineral content (BMC) and bone mineral density (BMD), whereas PTH increased BMC and BMD without a significant effect on bone size. GH increased both periosteal and endocortical bone formation and cortical size, while PTH increased only endocortical bone formation. GH mitigated the trabecular bone loss by increasing bone formation, while PTH increased bone mass by increasing bone formation and suppressing osteoclast number per bone area. The result of combined intervention shows an increase in trabecular, periosteal and endocortical bone formation and suppression of bone resorption resulting in a synergistic effect on increasing trabecular and cortical bone volume and BMD. The combination treatment of PTH and GH increases bone growth, bone formation, decreases bone resorption and has a synergistic effect on increasing bone density and bone mass. Copyright (c) 2010 S. Karger AG, Basel.

  20. A synchrotron radiation microtomography system for the analysis of trabecular bone samples.

    Science.gov (United States)

    Salomé, M; Peyrin, F; Cloetens, P; Odet, C; Laval-Jeantet, A M; Baruchel, J; Spanne, P

    1999-10-01

    X-ray computed microtomography is particularly well suited for studying trabecular bone architecture, which requires three-dimensional (3-D) images with high spatial resolution. For this purpose, we describe a three-dimensional computed microtomography (microCT) system using synchrotron radiation, developed at ESRF. Since synchrotron radiation provides a monochromatic and high photon flux x-ray beam, it allows high resolution and a high signal-to-noise ratio imaging. The principle of the system is based on truly three-dimensional parallel tomographic acquisition. It uses a two-dimensional (2-D) CCD-based detector to record 2-D radiographs of the transmitted beam through the sample under different angles of view. The 3-D tomographic reconstruction, performed by an exact 3-D filtered backprojection algorithm, yields 3-D images with cubic voxels. The spatial resolution of the detector was experimentally measured. For the application to bone investigation, the voxel size was set to 6.65 microm, and the experimental spatial resolution was found to be 11 microm. The reconstructed linear attenuation coefficient was calibrated from hydroxyapatite phantoms. Image processing tools are being developed to extract structural parameters quantifying trabecular bone architecture from the 3-D microCT images. First results on human trabecular bone samples are presented.

  1. Assessing vertebral fracture risk on volumetric quantitative computed tomography by geometric characterization of trabecular bone structure

    Science.gov (United States)

    Checefsky, Walter A.; Abidin, Anas Z.; Nagarajan, Mahesh B.; Bauer, Jan S.; Baum, Thomas; Wismüller, Axel

    2016-03-01

    The current clinical standard for measuring Bone Mineral Density (BMD) is dual X-ray absorptiometry, however more recently BMD derived from volumetric quantitative computed tomography has been shown to demonstrate a high association with spinal fracture susceptibility. In this study, we propose a method of fracture risk assessment using structural properties of trabecular bone in spinal vertebrae. Experimental data was acquired via axial multi-detector CT (MDCT) from 12 spinal vertebrae specimens using a whole-body 256-row CT scanner with a dedicated calibration phantom. Common image processing methods were used to annotate the trabecular compartment in the vertebral slices creating a circular region of interest (ROI) that excluded cortical bone for each slice. The pixels inside the ROI were converted to values indicative of BMD. High dimensional geometrical features were derived using the scaling index method (SIM) at different radii and scaling factors (SF). The mean BMD values within the ROI were then extracted and used in conjunction with a support vector machine to predict the failure load of the specimens. Prediction performance was measured using the root-mean-square error (RMSE) metric and determined that SIM combined with mean BMD features (RMSE = 0.82 +/- 0.37) outperformed MDCT-measured mean BMD (RMSE = 1.11 +/- 0.33) (p biomechanical strength prediction in vertebrae can be significantly improved through the use of SIM-derived texture features from trabecular bone.

  2. Characterizing trabecular bone structure for assessing vertebral fracture risk on volumetric quantitative computed tomography

    Science.gov (United States)

    Nagarajan, Mahesh B.; Checefsky, Walter A.; Abidin, Anas Z.; Tsai, Halley; Wang, Xixi; Hobbs, Susan K.; Bauer, Jan S.; Baum, Thomas; Wismüller, Axel

    2015-03-01

    While the proximal femur is preferred for measuring bone mineral density (BMD) in fracture risk estimation, the introduction of volumetric quantitative computed tomography has revealed stronger associations between BMD and spinal fracture status. In this study, we propose to capture properties of trabecular bone structure in spinal vertebrae with advanced second-order statistical features for purposes of fracture risk assessment. For this purpose, axial multi-detector CT (MDCT) images were acquired from 28 spinal vertebrae specimens using a whole-body 256-row CT scanner with a dedicated calibration phantom. A semi-automated method was used to annotate the trabecular compartment in the central vertebral slice with a circular region of interest (ROI) to exclude cortical bone; pixels within were converted to values indicative of BMD. Six second-order statistical features derived from gray-level co-occurrence matrices (GLCM) and the mean BMD within the ROI were then extracted and used in conjunction with a generalized radial basis functions (GRBF) neural network to predict the failure load of the specimens; true failure load was measured through biomechanical testing. Prediction performance was evaluated with a root-mean-square error (RMSE) metric. The best prediction performance was observed with GLCM feature `correlation' (RMSE = 1.02 ± 0.18), which significantly outperformed all other GLCM features (p biomechanical strength prediction in spinal vertebrae can be significantly improved through characterization of trabecular bone structure with GLCM-derived texture features.

  3. Neocellularization and neovascularization of nanosized bioactive glass-coated decellularized trabecular bone scaffolds

    KAUST Repository

    Gerhardt, Lutz Christian

    2012-09-11

    In this study, the in vivo recellularization and neovascularization of nanosized bioactive glass (n-BG)-coated decellu-larized trabecular bone scaffolds were studied in a rat model and quantified using stereological analyses. Based on the highest amount of vascular endothelial growth factor (VEGF) secreted by human fibroblasts grown on n-BG coatings (0-1.245 mg/cm 2), decellularized trabecular bone samples (porosity: 43-81%) were coated with n-BG particles. Grown on n-BG particles at a coating density of 0.263 mg/cm2, human fibroblasts produced 4.3 times more VEGF than on uncoated controls. After 8 weeks of implantation in Sprague-Dawley rats, both uncoated and n-BG-coated samples were well infiltrated with newly formed tissue (47-48%) and blood vessels (3-4%). No significant differences were found in cellularization and vascularization between uncoated bone scaffolds and n-BG-coated scaffolds. This finding indicates that the decellularized bone itself may exhibit growth-promoting properties induced by the highly interconnected pore microarchitecture and/or proteins left behind on decellularized scaffolds. Even if we did not find proangiogenic effects in n-BG-coated bone scaffolds, a bioactive coating is considered to be beneficial to impart osteoinductive and osteoconductive properties to decellularized bone. n-BG-coated bone grafts have thus high clinical potential for the regeneration of complex tissue defects given their ability for recellularization and neovascularization. © 2012 Wiley Periodicals, Inc.

  4. Strain analysis of trabecular bone using time-resolved X-ray microtomography

    Czech Academy of Sciences Publication Activity Database

    Jiroušek, Ondřej; Zlámal, Petr; Kytýř, Daniel; Kroupa, M.

    2011-01-01

    Roč. 633, Suppl. 1 (2011), s. 148-151 ISSN 0168-9002. [International Workshop on Radiation Imaging Detectors /11./. Praha, 28.06.2009-02.07.2009] R&D Projects: GA ČR(CZ) GP103/07/P483 Institutional research plan: CEZ:AV0Z20710524 Keywords : trabecular bone * X-ray microtomography * strain analysis * intrinsic material properties Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 1.207, year: 2011

  5. Effect of swimming exercise on three-dimensional trabecular bone microarchitecture in ovariectomized rats.

    Science.gov (United States)

    Ju, Yong-In; Sone, Teruki; Ohnaru, Kazuhiro; Tanaka, Kensuke; Fukunaga, Masao

    2015-11-01

    Swimming is generally considered ineffective for increasing bone mass in humans, at least compared with weight-bearing sports. However, swimming exercise has sometimes been shown to have a strong positive effect on bone mass in small animals. This study investigated the effects of swimming on bone mass, strength, and microarchitecture in ovariectomized (OVX) rats. OVX or sham operations were performed on 18-wk-old female Fisher 344 rats. Rats were randomly divided into four groups: sham sedentary (Sham-CON), sham swimming exercised (Sham-SWI), OVX sedentary (OVX-CON), and OVX swimming exercised (OVX-SWI). Rats in exercise groups performed swimming in a water bath for 60 min/day, 5 days/wk, for 12 wk. Bone mineral density (BMD) in right femurs was analyzed using dual-energy X-ray absorptiometry. Three-dimensional trabecular architecture at the distal femoral metaphysis was analyzed using microcomputed tomography (μCT). Geometrical properties of diaphyseal cortical bone were evaluated in the midfemoral region using μCT. The biomechanical properties of femurs were analyzed using three-point bending. Femoral BMD was significantly decreased following ovariectomy. This change was suppressed by swimming. Trabecular bone thickness, number, and connectivity were decreased by ovariectomy, whereas structure model index (i.e., ratio of rod-like to plate-like trabeculae) increased. These changes were also suppressed by swimming exercise. Femurs displayed greater cortical width and maximum load in SWI groups than in CON groups. Together, these results demonstrate that swimming exercise drastically alleviated both OVX-induced decreases in bone mass and mechanical strength and the deterioration of trabecular microarchitecture in rat models of osteoporosis. Copyright © 2015 the American Physiological Society.

  6. Trabecular bone histomorphometry in humans with Type 1 Diabetes Mellitus.

    Science.gov (United States)

    Armas, Laura A G; Akhter, Mohammed P; Drincic, Andjela; Recker, Robert R

    2012-01-01

    Patients with Type 1 Diabetes Mellitus (DM) have markedly increased risk of fracture, but little is known about abnormalities in bone microarchitecture or remodeling properties that might give insight into the pathogenesis of skeletal fragility in these patients. We report here a case-control study comparing bone histomorphometric and micro-CT results from iliac biopsies in 18 otherwise healthy subjects with Type 1 Diabetes Mellitus with those from healthy age- and sex-matched non-diabetic control subjects. Five of the diabetics had histories of low-trauma fracture. Transilial bone biopsies were obtained after tetracycline labeling. The biopsy specimens were fixed, embedded, and scanned using a desktop μCT at 16 μm resolution. They were then sectioned and quantitative histomorphometry was performed as previously described by Recker et al. [1]. Two sections, >250 μm apart, were read from the central part of each biopsy. Overall there were no significant differences between diabetics and controls in histomorphometric or micro-CT measurements. However, fracturing diabetics had structural and dynamic trends different from nonfracturing diabetics by both methods of analysis. In conclusion, Type 1 Diabetes Mellitus does not result in abnormalities in bone histomorphometric or micro-CT variables in the absence of manifest complications from the diabetes. However, diabetics suffering fractures may have defects in their skeletal microarchitecture that may underlie the presence of excess skeletal fragility. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Expanding the Description of Spaceflight Effects beyond Bone Mineral Density [BMD]: Trabecular Bone Score [TBS] in ISS Astronauts

    Science.gov (United States)

    Sibonga, J. D.; Spector, E. R.; King, L. J.; Evans, H. J.; Smith, S. A.

    2014-01-01

    Dual-energy x-ray absorptiometry [DXA] is the widely-applied bone densitometry method used to diagnose osteoporosis in a terrestrial population known to be at risk for age-related bone loss. This medical test, which measures areal bone mineral density [aBMD] of clinically-relevant skeletal sites (e.g., hip and spine), helps the clinician to identify which persons, among postmenopausal women and men older than 50 years, are at high risk for low trauma or fragility fractures and might require an intervention. The most recognized osteoporotic fragility fracture is the vertebral compression fracture which can lead to kyphosis or hunched backs typically seen in the elderly. DXA measurement of BMD however is recognized to be insufficient as a sole index for assessing fracture risk. DXA's limitation may be related to its inability to monitor changes in structural parameters, such as trabecular vs. cortical bone volumes, bone geometry or trabecular microarchitecture. Hence, in order to understand risks to human health and performance due to space exposure, NASA needs to expand its measurements of bone to include other contributors to skeletal integrity. To this aim, the Bone and Mineral Lab conducted a pilot study for a novel measurement of bone microarchitecture that can be obtained by retrospective analysis of DXA scans. Trabecular Bone Score (TBS) assesses changes to trabecular microarchitecture by measuring the grey color "texture" information extracted from DXA images of the lumbar spine. An analysis of TBS in 51 ISS astronauts was conducted to assess if TBS could detect 1) an effect of spaceflight and 2) a response to countermeasures independent of DXA BMD. In addition, changes in trunk body lean tissue mass and in trunk body fat tissue mass were also evaluated to explore an association between body composition, as impacted by ARED exercise, and bone microarchitecture. The pilot analysis of 51 astronaut scans of the lumbar spine suggests that, following an ISS

  8. Assessment of trabecular bone changes around endosseous implants using image analysis techniques: A preliminary study

    International Nuclear Information System (INIS)

    Zuki, Mervet El; Omami, Galal; Horner, Keith

    2014-01-01

    The objective of this study was to assess the trabecular bone changes that occurred around functional endosseous dental implants by means of radiographic image analysis techniques. Immediate preoperative and postoperative periapical radiographs of de-identified implant patients at the University Dental Hospital of Manchester were retrieved, screened for specific inclusion criteria, digitized, and quantified for structural elements of the trabecular bone around the endosseous implants, by using image analysis techniques. Data were analyzed using SPSS version 11.5. P values of less than 0.05 were considered statistically significant. A total of 12 implants from 11 patients were selected for the study, and 26 regions of interest were obtained. There was a significant increase in the bone area in terms of the mean distance between nodes (p=0.006) and a significant decrease in the marrow area in terms of the bone area (p=0.006) and the length of marrow spaces (p=0.032). It appeared that the bone around the implant underwent remodeling that resulted in a net increase in bone after implant placement.

  9. Assessment of trabecular bone changes around endosseous implants using image analysis techniques: A preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Zuki, Mervet El [Dept. of Oral Medicine and Radiology, Benghazi University College of Dentistry, Benghazi (Libya); Omami, Galal [Oral Diagnosis and Polyclinics, Faculty of Dentistry, The University of Hong Kong (Hong Kong); Horner, Keith [Dept. of Oral Radiology, University Dental Hospital of Manchester, Manchester (United Kingdom)

    2014-06-15

    The objective of this study was to assess the trabecular bone changes that occurred around functional endosseous dental implants by means of radiographic image analysis techniques. Immediate preoperative and postoperative periapical radiographs of de-identified implant patients at the University Dental Hospital of Manchester were retrieved, screened for specific inclusion criteria, digitized, and quantified for structural elements of the trabecular bone around the endosseous implants, by using image analysis techniques. Data were analyzed using SPSS version 11.5. P values of less than 0.05 were considered statistically significant. A total of 12 implants from 11 patients were selected for the study, and 26 regions of interest were obtained. There was a significant increase in the bone area in terms of the mean distance between nodes (p=0.006) and a significant decrease in the marrow area in terms of the bone area (p=0.006) and the length of marrow spaces (p=0.032). It appeared that the bone around the implant underwent remodeling that resulted in a net increase in bone after implant placement.

  10. Micro-finite-element method to assess elastic properties of trabecular bone at micro- and macroscopic level.

    Science.gov (United States)

    Rieger, R; Auregan, J C; Hoc, T

    2018-03-01

    The objective of the present study is to assess the mechanical behavior of trabecular bone based on microCT imaging and micro-finite-element analysis. In this way two methods are detailed: (i) direct determination of macroscopic elastic property of trabecular bone; (ii) inverse approach to assess mechanical properties of trabecular bone tissue. Thirty-five females and seven males (forty-two subjects) mean aged (±SD) 80±11.7 years from hospitals of Assistance publique-Hôpitaux de Paris (AP-HP) diagnosed with osteoporosis following a femoral neck fracture due to a fall from standing were included in this study. Fractured heads were collected during hip replacement surgery. Standardized bone cores were removed from the femoral head's equator by a trephine in a water bath. MicroCT images acquisition and analysis were performed with CTan ® software and bone volume fraction was then determined. Micro-finite-element simulations were per-formed using Abaqus 6.9-2 ® software in order to determine the macroscopic mechanical behaviour of the trabecular bone. After microCT acquisition, a longitudinal compression test was performed and the experimental macroscopic Young's Modulus was extracted. An inverse approach based on the whole trabecular bone's mechanical response and micro-finite-element analysis was performed to determine microscopic mechanical properties of trabecular bone. In the present study, elasticity of the tissue was shown to be similar to that of healthy tissue but with a lower yield stress. Classical histomorphometric analysis form microCT imaging associated with an inverse micro-finite-element method allowed to assess microscopic mechanical trabecular bone parameters. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  11. Orientation-weighted local Minkowski functionals in 3D for quantitative assessment of trabecular bone structure in the hip

    Science.gov (United States)

    Boehm, H. F.; Bitterling, H.; Weber, C.; Kuhn, V.; Eckstein, F.; Reiser, M.

    2007-03-01

    Fragility fractures or pathologic fractures of the hip, i.e. fractures with no apparent trauma, represent the worst complication in osteoporosis with a mortality close to 25% during the first post-traumatic year. Over 90% of hip fractures result from falls from standing height. A substantial number of femoral fractures are initiated in the femoral neck or the trochanteric regions which contain an internal architecture of trabeculae that are functionally highly specialized to withstand the complex pattern of external and internal forces associated with human gait. Prediction of the mechanical strength of bone tissue can be achieved by dedicated texture analysis of data obtained by high resolution imaging modalities, e.g. computed tomography (CT) or magnetic resonance tomography (MRI). Since in the case of the proximal femur, the connectivity, regional distribution and - most of all - the preferred orientation of individual trabeculae change considerably within narrow spatial limits, it seems most reasonable to evaluate the femoral bone structure on an orientation-weighted, local scale. In past studies, we could demonstrate the advantages of topological analysis of bone structure using the Minkowski Functionals in 3D on a global and on a local scale. The current study was designed to test the hypothesis that the prediction of the mechanical competence of the proximal femur by a new algorithm considering orientational changes of topological properties in the trabecular architecture is feasible and better suited than conventional methods based on the measurement of the mineral density of bone tissue (BMD).

  12. Contribution of the endosteal surface of cortical bone to the trabecular pattern seen on IOPA radiographs: an in vitro study

    Directory of Open Access Journals (Sweden)

    P T Ravikumar

    2012-01-01

    Full Text Available Objectives: A study was conducted to assess the contribution of the cancellous and endosteal surface of the cortical bone to the trabecular pattern seen in an IOPA radiograph. Materials and methods: An in vitro study analyzing the contribution of the endosteal surface of cortical bone and cancellous bone to the trabecular pattern was conducted, using 60 specimens of desiccated human mandibles. The mode of execution involved IOPA radiographic evaluation of premolarmolar segments in the specimens before and after removal of cancellous bone. The radiographs were numbered for identification and subjected to evaluation by 5 dentomaxillofacial radiologists who were doubleblinded to ensure an unbiased interpretation. Results: The trabecular pattern appreciation by the experts in the IOPA radiographs before and after removal of cancellous bone displayed immaculate correlation as per the Goodman-Kruskal Gamma Coefficient values which was 0.78 indicating a very large correlation. The relative density of trabecular pattern was significantly higher in radiograph before than after removal of cancellous bone with p-value less than 0.05. Conclusion: Based on these results it was adjudged that both the cancellous and endosteal surface of cortical bone contributed significantly to the trabecular pattern in an IOPA radiograph.

  13. Age-related changes in cortical and trabecular bone mineral status: A quantitative CT study in lumbar vertebrae

    International Nuclear Information System (INIS)

    Tanno, M.; Horiuchi, T.; Nakajima, I.; Maeda, S.; Igarashi, M.; Yamada, H.

    2000-01-01

    To investigate the age and sex dependence of the bone mineral status of human lumbar vertebrae with special regard to differences between cortical and trabecular bone. The study group comprised 125 normal Japanese healthy volunteers (54 males and 71 females), and was subdivided into adult male and female groups (subjects younger than 40 years), intermediate male and female groups (ages ranging between 41 and 64 years) and old male and female groups (subjects older than 65 years). The cortical bone mineral status was estimated using a single-energy quantitative CT (SE-QCT) technique, whereas trabecular bone mineral density (BMD) was estimated using a dual-energy (DE-QCT) technique. A considerable gender difference in the age-related cortical bone status was found. There was a significant reduction of the mean values of the cortical volume and BMD in the old female group compared with those obtained in the old male group. The results suggest that in men, cortical and trabecular bone volume decrease very little with age. In women, cortical volume and BMD and trabecular BMD decrease with age while trabecular bone volume does not. The study showed that all variables had higher values in men than in women and that the difference increased with age

  14. 3D histomorphometric quantification of trabecular bones by computed microtomography using synchrotron radiation.

    Science.gov (United States)

    Nogueira, L P; Braz, D; Barroso, R C; Oliveira, L F; Pinheiro, C J G; Dreossi, D; Tromba, G

    2010-12-01

    Conventional bone histomorphometry is an important method for quantitative evaluation of bone microstructure. X-ray computed microtomography is a non-invasive technique, which can be used to evaluate histomorphometric indices in trabecular bones (BV/TV, BS/BV, Tb.N, Tb.Th, Tb.Sp). In this technique, 3D images are used to quantify the whole sample, differently from the conventional one, in which the quantification is performed in 2D slices and extrapolated for 3D case. In this work, histomorphometric quantification using synchrotron 3D X-ray computed microtomography was performed to quantify the bone structure at different skeletal sites as well as to investigate the effects of bone diseases on quantitative understanding of bone architecture. The images were obtained at Synchrotron Radiation for MEdical Physics (SYRMEP) beamline, at ELETTRA synchrotron radiation facility, Italy. Concerning the obtained results for normal and pathological bones from same skeletal sites and individuals, from our results, a certain declining bone volume fraction was achieved. The results obtained could be used in forming the basis for comparison of the bone microarchitecture and can be a valuable tool for predicting bone fragility. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. Skeletal development of mice lacking bone sialoprotein (BSP--impairment of long bone growth and progressive establishment of high trabecular bone mass.

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    Wafa Bouleftour

    Full Text Available Adult Ibsp-knockout mice (BSP-/- display shorter stature, lower bone turnover and higher trabecular bone mass than wild type, the latter resulting from impaired bone resorption. Unexpectedly, BSP knockout also affects reproductive behavior, as female mice do not construct a proper "nest" for their offsprings. Multiple crossing experiments nonetheless indicated that the shorter stature and lower weight of BSP-/- mice, since birth and throughout life, as well as their shorter femur and tibia bones are independent of the genotype of the mothers, and thus reflect genetic inheritance. In BSP-/- newborns, µCT analysis revealed a delay in membranous primary ossification, with wider cranial sutures, as well as thinner femoral cortical bone and lower tissue mineral density, reflected in lower expression of bone formation markers. However, trabecular bone volume and osteoclast parameters of long bones do not differ between genotypes. Three weeks after birth, osteoclast number and surface drop in the mutants, concomitant with trabecular bone accumulation. The growth plates present a thinner hypertrophic zone in newborns with lower whole bone expression of IGF-1 and higher IHH in 6 days old BSP-/- mice. At 3 weeks the proliferating zone is thinner and the hypertrophic zone thicker in BSP-/- than in BSP+/+ mice of either sex, maybe reflecting a combination of lower chondrocyte proliferation and impaired cartilage resorption. Six days old BSP-/- mice display lower osteoblast marker expression but higher MEPE and higher osteopontin(Opn/Runx2 ratio. Serum Opn is higher in mutants at day 6 and in adults. Thus, lack of BSP alters long bone growth and membranous/cortical primary bone formation and mineralization. Endochondral development is however normal in mutant mice and the accumulation of trabecular bone observed in adults develops progressively in the weeks following birth. Compensatory high Opn may allow normal endochondral development in BSP-/- mice

  16. Preliminary result on trabecular bone score (TBS in lumbar vertebrae with experimentally altered microarchitecture

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    M. Di Stefano

    2013-01-01

    Full Text Available The aim of this preliminary research is to investigate the reliability of a new qualitative parameter, called Trabecular Bone Score (TBS, recently proposed for evaluating the microarchitectural arrangement of cancellous bone in scans carried out by dual energy X-ray absorptiometry (DXA. Vertebral bodies of 15 fresh samples of lumbar spines of adult pig were analysed either in basal conditions and with altered microarchitecture of the cancellous bone obtained by progressive drilling. The examined bony areas do not show changes in bone mineral density (BMD, whereas TBS values decrease with the increasing alteration of the vertebral microtrabecular structure. Our preliminary data seem to confirm the reliability of TBS as a qualitative parameter useful for evaluating the microarchitectural strength in bony areas quantitatively analysed by DXA.

  17. Effect of a novel load-bearing trabecular Nitinol scaffold on rabbit radius bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Gotman, Irena, E-mail: gotman@technion.ac.il; Gutmanas, Elazar Y., E-mail: gutmanas@technion.ac.il [Department of Materials Science and Engineering, Techion-Israel Institute of Technology, Haifa, 32000 Israel (Israel); National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Zaretzky, Asaph [The Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, 31096 Israel (Israel); Psakhie, Sergey G. [National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation)

    2015-10-27

    The research aim was to evaluate the bone regeneration capability of novel load-bearing NiTi alloy (Nitinol) scaffolds in a critical-size defect (CSD) model. High strength “trabecular Nitinol” scaffolds were prepared by PIRAC (Powder Immersion Reaction Assisted Coating) annealing of the highly porous Ni foam in Ti powder at 900°C. This was followed by PIRAC nitriding to mitigate the release of potentially toxic Ni ions. Scaffolds phase composition and microstructure were characterized by X-ray diffraction and scanning electron microscopy (SEM/EDS), and their mechanical properties were tested in compression. New Zealand white rabbits received bone defect in right radius and were divided in four groups randomly. In the control group, nothing was placed in the defect. In other groups, NiTi scaffolds were implanted in the defect: (i) as produced, (ii) loaded with bone marrow aspirate (BMA), and (iii) biomimetically CaP-coated. The animals were sacrificed after 12 weeks. The forelimbs with scaffolds were resected, fixed, sectioned and examined in SEM. New bone formation inside the scaffold was studied by EDS analysis and by the processing of backscattered electron images. Bone ingrowth into the scaffold was observed in all implant groups, mostly next to the ulna. New bone formation was strongly enhanced by BMA loading and biomimeatic CaP coating, the bone penetrating as much as 1–1.5 mm into the scaffold. The results of this preliminary study demonstrate that the newly developed high strength trabecular Nitinol scaffolds can be successfully used for bone regeneration in critical size defects.

  18. Microstructural properties of trabecular bone autografts: comparison of men and women with and without osteoporosis.

    Science.gov (United States)

    Xie, Fen; Zhou, Bin; Wang, Jian; Liu, Tang; Wu, Xiyu; Fang, Rui; Kang, Yijun; Dai, Ruchun

    2018-03-05

    The microstructure of autologous bone grafts from men over 50 years old and postmenopausal women undergoing spinal fusion were evaluated using micro-CT. We demonstrated postmenopausal women, especially those with osteoporosis (OP) presented more serious microarchitectural deterioration of bone grafts. This study was undertaken to determine microstructural properties of cancellous bone used as autologous bone grafts from osteoporosis patients undergoing lumbar fusion by comparing microstructural indices to controls. Cancellous bone specimens from spinous processes were obtained from 41 postmenopausal women (osteoporosis women, n = 19; controls, n = 22) and 26 men over 50 years old (osteoporosis men, n = 8; controls, n = 18) during lumbar fusion surgery. The microstructural parameters were measured using micro-CT. Significant difference in bone volume fraction (BV/TV), specific bone surface (BS/BV), trabecular thickness (Tb.Th), and structure model index (SMI) value existed between postmenopausal women with OP and controls. Significant difference in trabecular number (Tb.N) existed between men over 50 years old with OP and controls. Postmenopausal women exhibited lower BV/TV, Tb.Th, and higher SMI value than men over 50 years old. Postmenopausal women with OP exhibited lower BV/TV, Tb.Th, and higher BS/BV than men over 50 years old with OP. Post-menopausal women and older men with OP have worse bone quality in autografts than non-osteoporotic men and women. Postmenopausal women with OP presented serious microarchitectural deterioration in older population.

  19. Assessment of jawbone trabecular bone structure amongst osteoporotic women by cone-beam computed tomography: the OSTEOSYR project.

    Science.gov (United States)

    Barngkgei, Imad; Al Haffar, Iyad; Shaarani, Eyad; Khattab, Razan; Mashlah, Ammar

    2016-11-01

    To assess the trabecular bone structure of jawbones and the dens (the odontoid process of the second cervical vertebra) amongst osteoporotic and nonosteoporotic women using cone-beam computed tomography (CBCT). Analysis of the dens trabecular bone structure aimed to test the validity of CBCT in such analysis. Thirty-eight women who went under dual-energy X-ray absorptiometry (DXA) examination were scanned by CBCT. Cuboids from different areas of jawbones and the dens were extracted from each scan. Trabecular thickness (Tb.Th), trabecular separation (Tb.S), bone volume fraction (BV/TV), specific bone surface (BS/TV) and connectivity density were calculated. Student's t-test, Pearson correlation, and logistic regression analysis were used to explore differences in these measures between groups. Jawbone-derived measures showed insignificant differences (P > 0.05) between osteoporotic and non-osteoporotic groups, and weak correlations with femoral neck and lumbar vertebrae T-scores (r ≤ 0.4). Dens-derived measures, however, resulted in the opposite (r = 0.34-0.38 [P value = 0.02-0.036] and r = 0.48-0.61 [P value ≤ 0.003]) and the highest accuracy of osteoporosis prediction: 84.2% and 78.9% respectively. Trabecular bone structure of the mandible and maxilla is not affected in osteoporosis as assessed by CBCT. Dens trabecular bone analysis revealed the opposite, so some trabecular bone measures may be assessed by CBCT, which may aid in predicting osteoporosis. © 2015 Wiley Publishing Asia Pty Ltd.

  20. Assessment of vertebral microarchitecture in overt and mild Cushing's syndrome using trabecular bone score.

    Science.gov (United States)

    Vinolas, Helene; Grouthier, Virginie; Mehsen-Cetre, Nadia; Boisson, Amandine; Winzenrieth, Renaud; Schaeverbeke, Thierry; Mesguich, Charles; Bordenave, Laurence; Tabarin, Antoine

    2018-05-21

    Osteoporotic fractures associated with Cushing's syndrome (CS) may occur despite normal bone mineral density (BMD). Few studies have described alterations in vertebral microarchitecture in glucocorticoid-treated patients and during CS. Trabecular bone score (TBS) estimates trabecular microarchitecture from dual-energy X-ray absorptiometry acquisitions. Our aim was to compare vertebral BMD and TBS in patients with overt CS and mild autonomous cortisol secretion (MACE), and following cure of overt CS. University Hospital. Monocentric retrospective cross-sectional and longitudinal studies of consecutive patients. A total of 110 patients were studied: 53 patients had CS (35, 11 and 7 patients with Cushing's disease, bilateral macronodular adrenal hyperplasia and ectopic ACTH secretion respectively); 39 patients had MACE (10 patients with a late post-operative recurrence of Cushing's disease and 29 patients with adrenal incidentalomas); 18 patients with non-secreting adrenal incidentalomas. 14 patients with overt CS were followed for up to 2 years after cure. Vertebral osteoporosis at BMD and degraded microarchitecture at TBS were found in 24% and 43% of patients with CS, respectively (P < .03). As compared to patients with nonsecreting incidentalomas, patients with MACE had significantly decreased TBS (P < .04) but not BMD. Overt fragility fractures tended to be associated with low TBS (P = .07) but not with low BMD. TBS, but not BMD values, decreased with the intensity of hypercortisolism independently of its aetiology (P < .01). Following remission of CS, TBS improved more markedly and rapidly than BMD (10% vs 3%, respectively; P < .02). Trabecular bone score may be a promising, noninvasive, widely available and inexpensive complementary tool for the routine assessment of the impact of CS and MACE on bone in clinical practice. © 2018 John Wiley & Sons Ltd.

  1. Estimating the mechanical competence parameter of the trabecular bone: a neural network approach

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    Érica Regina Filletti

    Full Text Available Abstract Introduction The mechanical competence parameter (MCP of the trabecular bone is a parameter that merges the volume fraction, connectivity, tortuosity and Young modulus of elasticity, to provide a single measure of the trabecular bone structural quality. Methods As the MCP is estimated for 3D images and the Young modulus simulations are quite consuming, in this paper, an alternative approach to estimate the MCP based on artificial neural network (ANN is discussed considering as the training set a group of 23 in vitro vertebrae and 12 distal radius samples obtained by microcomputed tomography (μCT, and 83 in vivo distal radius magnetic resonance image samples (MRI. Results It is shown that the ANN was able to predict with very high accuracy the MCP for 29 new samples, being 6 vertebrae and 3 distal radius bones by μCT and 20 distal radius bone by MRI. Conclusion There is a strong correlation (R2 = 0.97 between both techniques and, despite the small number of testing samples, the Bland-Altman analysis shows that ANN is within the limits of agreement to estimate the MCP.

  2. Fabrication of Trabecular Bone-Templated Tissue-Engineered Constructs by 3D Inkjet Printing.

    Science.gov (United States)

    Vanderburgh, Joseph P; Fernando, Shanik J; Merkel, Alyssa R; Sterling, Julie A; Guelcher, Scott A

    2017-11-01

    3D printing enables the creation of scaffolds with precisely controlled morphometric properties for multiple tissue types, including musculoskeletal tissues such as cartilage and bone. Computed tomography (CT) imaging has been combined with 3D printing to fabricate anatomically scaled patient-specific scaffolds for bone regeneration. However, anatomically scaled scaffolds typically lack sufficient resolution to recapitulate the 3D constructs are fabricated via a new micro-CT/3D inkjet printing process. It is shown that this process reproducibly fabricates bone-templated constructs that recapitulate the anatomic site-specific morphometric properties of trabecular bone. A significant correlation is observed between the structure model index (a morphometric parameter related to surface curvature) and the degree of mineralization of human mesenchymal stem cells, with more concave surfaces promoting more extensive osteoblast differentiation and mineralization compared to predominately convex surfaces. These findings highlight the significant effects of trabecular architecture on osteoblast function. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Characterization of synthetic foam structures used to manufacture artificial vertebral trabecular bone.

    Science.gov (United States)

    Fürst, David; Senck, Sascha; Hollensteiner, Marianne; Esterer, Benjamin; Augat, Peter; Eckstein, Felix; Schrempf, Andreas

    2017-07-01

    Artificial materials reflecting the mechanical properties of human bone are essential for valid and reliable implant testing and design. They also are of great benefit for realistic simulation of surgical procedures. The objective of this study was therefore to characterize two groups of self-developed synthetic foam structures by static compressive testing and by microcomputed tomography. Two mineral fillers and varying amounts of a blowing agent were used to create different expansion behavior of the synthetic open-cell foams. The resulting compressive and morphometric properties thus differed within and also slightly between both groups. Apart from the structural anisotropy, the compressive and morphometric properties of the synthetic foam materials were shown to mirror the respective characteristics of human vertebral trabecular bone in good approximation. In conclusion, the artificial materials created can be used to manufacture valid synthetic bones for surgical training. Further, they provide novel possibilities for studying the relationship between trabecular bone microstructure and biomechanical properties. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Trabecular bone structure parameters from 3D image processing of clinical multi-slice and cone-beam computed tomography data

    Energy Technology Data Exchange (ETDEWEB)

    Klintstroem, Eva; Smedby, Oerjan [Linkoeping University, Center for Medical Image Science and Visualization (CMIV), Linkoeping (Sweden); UHL County Council of Oestergoetland, Department of Radiology, Linkoeping (Sweden); Linkoeping University, Department of Medical and Health Sciences (IMH)/Radiology, Linkoeping (Sweden); Moreno, Rodrigo [Linkoeping University, Center for Medical Image Science and Visualization (CMIV), Linkoeping (Sweden); Linkoeping University, Department of Medical and Health Sciences (IMH)/Radiology, Linkoeping (Sweden); Brismar, Torkel B. [KUS Huddinge, Department of Clinical Science, Intervention and Technology at Karolinska Institutet and Department of Radiology, Stockholm (Sweden)

    2014-02-15

    Bone strength depends on both mineral content and bone structure. The aim of this in vitro study was to develop a method of quantitatively assessing trabecular bone structure by applying three-dimensional image processing to data acquired with multi-slice and cone-beam computed tomography using micro-computed tomography as a reference. Fifteen bone samples from the radius were examined. After segmentation, quantitative measures of bone volume, trabecular thickness, trabecular separation, trabecular number, trabecular nodes, and trabecular termini were obtained. The clinical machines overestimated bone volume and trabecular thickness and underestimated trabecular nodes and number, but cone-beam CT to a lesser extent. Parameters obtained from cone beam CT were strongly correlated with μCT, with correlation coefficients between 0.93 and 0.98 for all parameters except trabecular termini. The high correlation between cone-beam CT and micro-CT suggest the possibility of quantifying and monitoring changes of trabecular bone microarchitecture in vivo using cone beam CT. (orig.)

  5. Characterization of drug-release kinetics in trabecular bone from titania nanotube implants

    Directory of Open Access Journals (Sweden)

    Aw MS

    2012-09-01

    Full Text Available Moom Sinn Aw,1 Kamarul A Khalid,2,3 Karan Gulati,1 Gerald J Atkins,2 Peter Pivonka,4 David M Findlay,2 Dusan Losic11School of Chemical Engineering, 2Discipline of Orthopaedics and Trauma, The University of Adelaide, Adelaide, SA, Australia; 3Department of Orthopaedics, Traumatology and Rehabilitation, Faculty of Medicine, International Islamic University Malaysia, Kuantan, Pahang, Malaysia; 4Engineering Computational Biology Group, School of Computer Science and Software Engineering, The University of Western Australia, Perth, WA, AustraliaPurpose: The aim of this study was to investigate the application of the three-dimensional bone bioreactor for studying drug-release kinetics and distribution of drugs in the ex vivo cancellous bone environment, and to demonstrate the application of nanoengineered titanium (Ti wires generated with titania nanotube (TNT arrays as drug-releasing implants for local drug deliveryMethods: Nanoengineered Ti wires covered with a layer of TNT arrays implanted in bone were used as a drug-releasing implant. Viable bovine trabecular bone was used as the ex vivo bone substrate embedded with the implants and placed in the bone reactor. A hydrophilic fluorescent dye (rhodamine B was used as the model drug, loaded inside the TNT–Ti implants, to monitor drug release and transport in trabecular bone. The distribution of released model drug in the bone was monitored throughout the bone structure, and concentration profiles at different vertical (0–5 mm and horizontal (0–10 mm distances from the implant surface were obtained at a range of release times from 1 hour to 5 days.Results: Scanning electron microscopy confirmed that well-ordered, vertically aligned nanotube arrays were formed on the surface of prepared TNT–Ti wires. Thermogravimetric analysis proved loading of the model drug and fluorescence spectroscopy was used to show drug-release characteristics in-vitro. The drug release from implants inserted into bone ex

  6. Influence of Trabecular Bone on Peri-Implant Stress and Strain Based on Micro-CT Finite Element Modeling of Beagle Dog.

    Science.gov (United States)

    Liao, Sheng-Hui; Zhu, Xing-Hao; Xie, Jing; Sohodeb, Vikesh Kumar; Ding, Xi

    2016-01-01

    The objective of this investigation is to analyze the influence of trabecular microstructure modeling on the biomechanical distribution of the implant-bone interface. Two three-dimensional finite element mandible models, one with trabecular microstructure (a refined model) and one with macrostructure (a simplified model), were built. The values of equivalent stress at the implant-bone interface in the refined model increased compared with those of the simplified model and strain on the contrary. The distributions of stress and strain were more uniform in the refined model of trabecular microstructure, in which stress and strain were mainly concentrated in trabecular bone. It was concluded that simulation of trabecular bone microstructure had a significant effect on the distribution of stress and strain at the implant-bone interface. These results suggest that trabecular structures could disperse stress and strain and serve as load buffers.

  7. Adipose tissue depot volume relationships with spinal trabecular bone mineral density in African Americans with diabetes.

    Directory of Open Access Journals (Sweden)

    Gary C Chan

    Full Text Available Changes in select adipose tissue volumes may differentially impact bone mineral density. This study was performed to assess cross-sectional and longitudinal relationships between computed tomography-determined visceral (VAT, subcutaneous (SAT, inter-muscular (IMAT, and pericardial adipose tissue (PAT volumes with respective changes in thoracic vertebral and lumbar vertebral volumetric trabecular bone mineral density (vBMD in African Americans with type 2 diabetes. Generalized linear models were fitted to test relationships between baseline and change in adipose volumes with change in vBMD in 300 African American-Diabetes Heart Study participants; adjustment was performed for age, sex, diabetes duration, study interval, smoking, hypertension, BMI, kidney function, and medications. Participants were 50% female with mean ± SD age 55.1±9.0 years, diabetes duration 10.2±7.2 years, and BMI 34.7±7.7 kg/m2. Over 5.3 ± 1.4 years, mean vBMD decreased in thoracic/lumbar spine, while mean adipose tissue volumes increased in SAT, IMAT, and PAT, but not VAT depots. In fully-adjusted models, changes in lumbar and thoracic vBMD were positively associated with change in SAT (β[SE] 0.045[0.011], p<0.0001; 0.40[0.013], p = 0.002, respectively. Change in thoracic vBMD was positively associated with change in IMAT (p = 0.029 and VAT (p = 0.016; and change in lumbar vBMD positively associated with baseline IMAT (p<0.0001. In contrast, vBMD was not associated with change in PAT. After adjusting for BMI, baseline and change in volumes of select adipose depots were associated with increases in thoracic and lumbar trabecular vBMD in African Americans. Effects of adiposity on trabecular bone appear to be site-specific and related to factors beyond mechanical load.

  8. Scaling relations between trabecular bone volume fraction and microstructure at different skeletal sites.

    Science.gov (United States)

    Räth, Christoph; Baum, Thomas; Monetti, Roberto; Sidorenko, Irina; Wolf, Petra; Eckstein, Felix; Matsuura, Maiko; Lochmüller, Eva-Maria; Zysset, Philippe K; Rummeny, Ernst J; Link, Thomas M; Bauer, Jan S

    2013-12-01

    In this study, we investigated the scaling relations between trabecular bone volume fraction (BV/TV) and parameters of the trabecular microstructure at different skeletal sites. Cylindrical bone samples with a diameter of 8mm were harvested from different skeletal sites of 154 human donors in vitro: 87 from the distal radius, 59/69 from the thoracic/lumbar spine, 51 from the femoral neck, and 83 from the greater trochanter. μCT images were obtained with an isotropic spatial resolution of 26μm. BV/TV and trabecular microstructure parameters (TbN, TbTh, TbSp, scaling indices ( and σ of α and αz), and Minkowski Functionals (Surface, Curvature, Euler)) were computed for each sample. The regression coefficient β was determined for each skeletal site as the slope of a linear fit in the double-logarithmic representations of the correlations of BV/TV versus the respective microstructure parameter. Statistically significant correlation coefficients ranging from r=0.36 to r=0.97 were observed for BV/TV versus microstructure parameters, except for Curvature and Euler. The regression coefficients β were 0.19 to 0.23 (TbN), 0.21 to 0.30 (TbTh), -0.28 to -0.24 (TbSp), 0.58 to 0.71 (Surface) and 0.12 to 0.16 (), 0.07 to 0.11 (), -0.44 to -0.30 (σ(α)), and -0.39 to -0.14 (σ(αz)) at the different skeletal sites. The 95% confidence intervals of β overlapped for almost all microstructure parameters at the different skeletal sites. The scaling relations were independent of vertebral fracture status and similar for subjects aged 60-69, 70-79, and >79years. In conclusion, the bone volume fraction-microstructure scaling relations showed a rather universal character. © 2013.

  9. Using Non-linear Homogenization to Improve the Performance of Macroscopic Damage Models of Trabecular Bone.

    Science.gov (United States)

    Levrero-Florencio, Francesc; Pankaj, Pankaj

    2018-01-01

    Realistic macro-level finite element simulations of the mechanical behavior of trabecular bone, a cellular anisotropic material, require a suitable constitutive model; a model that incorporates the mechanical response of bone for complex loading scenarios and includes post-elastic phenomena, such as plasticity (permanent deformations) and damage (permanent stiffness reduction), which bone is likely to experience. Some such models have been developed by conducting homogenization-based multiscale finite element simulations on bone micro-structure. While homogenization has been fairly successful in the elastic regime and, to some extent, in modeling the macroscopic plastic response, it has remained a challenge with respect to modeling damage. This study uses a homogenization scheme to upscale the damage behavior from the tissue level (microscale) to the organ level (macroscale) and assesses the suitability of different damage constitutive laws. Ten cubic specimens were each subjected to 21 strain-controlled load cases for a small range of macroscopic post-elastic strains. Isotropic and anisotropic criteria were considered, density and fabric relationships were used in the formulation of the damage law, and a combined isotropic/anisotropic law with tension/compression asymmetry was formulated, based on the homogenized results, as a possible alternative to the currently used single scalar damage criterion. This computational study enhances the current knowledge on the macroscopic damage behavior of trabecular bone. By developing relationships of damage progression with bone's micro-architectural indices (density and fabric) the study also provides an aid for the creation of more precise macroscale continuum models, which are likely to improve clinical predictions.

  10. [Radiographic appraisal between metal and bone interosculate backfill after total hip arthroplasty with trabecular metal cup].

    Science.gov (United States)

    Li, Wei; Zhou, Yi-Xin; Wu, Jian; Xu, Hui; Ji, Song-Jie

    2009-02-15

    To evaluate the bone refilling in the interface between the trabecular metal (TM) acetabular shell and the bone surface according to consecutive X film measuring after surgery. From July 2006 to July 2007, 35 patients (40 hips) accepted total hip replacement using trabecular metal monoblock acetabular cup system (TM). The cup was made of a ellipse shaped press fit Tantalum shell and high cross-linked PE liner (Longevity) with 28 mm inner diameter. The patients demography was: 16 male (20 hips), 19 female (20 hips), 5 bilateral hip replacements, age from 41 - 71 (mean 53), including 18 avascular necrosis hips, 16 osteoarthritis hips (including those secondary to a dysplasia hip), 4 avascular necrosis hips after femoral neck fracture, 2 Ankylosis Spondylitis. All the 40 total hip replacements used posterior approach, using hemispherical acetabular reamer and 2 mm press fit of final metal shell without screw fixation. The consecutive X film was taken at the end time of surgery and 2, 6, 12, 24 weeks, and 12 months. The clinical results was evaluate according to Harris scoring system, and the standard pelvis AP X film was measured at the interface between metal shell and the acetabular bone surface, witch was divided into five regions (A, B, C, D, E). Totally 32 patients (37 hips) were followed with average 8.7 months (7 - 12 months). The Harris before surgery was 50.5 (32 - 85), promoted to 91.0 (72 - 100), including 29 excellent, 6 good, 2 fair, and the total excellent and good rate was 94.6%. Complications include 4 patients leg length discrepancy from 1 - 2 cm, 3 patients moderate thigh pain and released after conservative therapy. No infection and dislocation was found. Twenty-one patients (23 hips) were found lucent line at the bone-metal interface from 1 - 5 mm, most common in B region and BC boundary than C, D, and CD boundary. All the patients followed was found the lucent line disappeared and refilled with bone at X film 24 weeks after surgery, however, no

  11. Strength through structure: visualization and local assessment of the trabecular bone structure

    International Nuclear Information System (INIS)

    Raeth, C; Monetti, R; Bauer, J; Sidorenko, I; Mueller, D; Matsuura, M; Lochmueller, E-M; Zysset, P; Eckstein, F

    2008-01-01

    The visualization and subsequent assessment of the inner human bone structures play an important role for better understanding the disease- or drug-induced changes of bone in the context of osteoporosis giving prospect for better predictions of bone strength and thus of the fracture risk of osteoporotic patients. In this work, we show how the complex trabecular bone structure can be visualized using μCT imaging techniques at an isotropic resolution of 26 μm. We quantify these structures by calculating global and local topological and morphological measures, namely Minkowski functionals (MFs) and utilizing the (an-)isotropic scaling index method (SIM) and by deriving suitable texture measures based on MF and SIM. Using a sample of 151 specimens taken from human vertebrae in vitro, we correlate the texture measures with the mechanically measured maximum compressive strength (MCS), which quantifies the strength of the bone probe, by using Pearson's correlation coefficient. The structure parameters derived from the local measures yield good correlations with the bone strength as measured in mechanical tests. We investigate whether the performance of the texture measures depends on the MCS value by selecting different subsamples according to MCS. Considering the whole sample the results for the newly defined parameters are better than those obtained for the standard global histomorphometric parameters except for bone volume/total volume (BV/TV). If a subsample consisting only of weak bones is analysed, the local structural analysis leads to similar and even better correlations with MCS as compared to BV/TV. Thus, the MF and SIM yield additional information about the stability of the bone especially in the case of weak bones, which corroborates the hypothesis that the bone structure (and not only its mineral mass) constitutes an important component of bone stability.

  12. New bone formation and trabecular bone microarchitecture of highly porous tantalum compared to titanium implant threads: A pilot canine study.

    Science.gov (United States)

    Lee, Jin Whan; Wen, Hai Bo; Gubbi, Prabhu; Romanos, Georgios E

    2018-02-01

    This study evaluated new bone formation activities and trabecular bone microarchitecture within the highly porous region of Trabecular Metal™ Dental Implants (TM) and between the threads of Tapered Screw-Vent® Dental Implants (TSV) in fresh canine extraction sockets. Eight partially edentulated dogs received four implants (4.1 mmD × 13 mmL) bilaterally in mandibular fresh extraction sockets (32 TM, 32 TSV implants), and allowed to heal for 2, 4, 8, and 12 weeks. Calcein was administered to label mineralizing bone at 11 and 4 days before euthanasia for dogs undergoing all four healing periods. Biopsies taken at each time interval were examined histologically. Histomorphometric assay was conducted for 64 unstained and 64 stained slides at the region of interest (ROI) (6 mm long × 0.35 mm deep) in the midsections of the implants. Topographical and chemical analyses were also performed. Histomorphometry revealed significantly more new bone in the TM than in the TSV implants at each healing time (p = .0014, .0084, .0218, and .0251). Calcein-labeled data showed more newly mineralized bone in the TM group than in the TSV group at 2, 8, and 12 weeks (p = .045, .028, .002, respectively) but not at 4 weeks (p = .081). Histologically TM implants exhibited more bone growth and dominant new immature woven bone at an earlier time point than TSV implants. The parameters representing trabecular bone microarchitecture corroborated faster new bone formation in the TM implants when compared to the TSV implants. TM exhibited an irregular faceted topography compared to a relatively uniform microtextured surface for TSV. Chemical analysis showed peaks associated with each implant's composition material, and TSV also showed peaks reflecting the elements of the calcium phosphate blasting media. Results suggest that the healing pathway associated with the highly porous midsection of TM dental implant could enable faster and stronger secondary implant stability than

  13. Usefulness of the Trabecular Bone Score for assessing the risk of osteoporotic fracture.

    Science.gov (United States)

    Redondo, L; Puigoriol, E; Rodríguez, J R; Peris, P; Kanterewicz, E

    2018-04-01

    The trabecular bone score (TBS) is an imaging technique that assesses the condition of the trabecular microarchitecture. Preliminary results suggest that TBS, along with the bone mineral density assessment, could improve the calculation of the osteoporotic fracture risk. The aim of this study was to analyse TBS values and their relationship with the clinical characteristics, bone mineral density and history of fractures of a cohort of posmenopausal women. We analysed 2,257 posmenopausal women from the FRODOS cohort, which was created to determine the risk factors for osteoporotic fracture through a clinical survey and bone densitometry with vertebral morphometry. TBS was applied to the densitometry images. TBS values ≤1230 were considered indicative of degraded microarchitecture. We performed a simple and multiple linear regression to determine the factors associated with this index. The mean TBS value in L1-L4 was 1.203±0.121. Some 55.3% of the women showed values indicating degraded microarchitecture. In the multiple linear regression analysis, the factors associated with low TBS values were age, weight, height, spinal T-score, glucocorticoid treatment, presence of type 2 diabetes and a history of fractures due to frailty. TBS showed microarchitecture degradation values in the participants of the FRODOS cohort and was associated with anthropometric factors, low bone mineral density values, the presence of fractures, a history of type 2 diabetes mellitus and the use of glucocorticoids. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

  14. Sex-specific patterns in cortical and trabecular bone microstructure in the Kirsten Skeletal Collection, South Africa.

    Science.gov (United States)

    Beresheim, Amy C; Pfeiffer, Susan K; Grynpas, Marc D; Alblas, Amanda

    2018-02-07

    The purpose of this study was to provide bone histomorphometric reference data for South Africans of the Western Cape who likely dealt with health issues under the apartheid regime. The 206 adult individuals ( n female = 75, n male = 131, mean = 47.9 ± 15.8 years) from the Kirsten Skeletal Collection, U. Stellenbosch, lived in the Cape Town metropole from the late 1960s to the mid-1990s. To study age-related changes in cortical and trabecular bone microstructure, photomontages of mid-thoracic rib cross-sections were quantitatively examined. Variables include relative cortical area (Rt.Ct.Ar), osteon population density (OPD), osteon area (On.Ar), bone volume fraction (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), and trabecular spacing (Tb.Sp). All cortical variables demonstrated significant relationships with age in both sexes, with women showing stronger overall age associations. Peak bone mass was compromised in some men, possibly reflecting poor nutritional quality and/or substance abuse issues throughout adolescence and early adulthood. In women, greater predicted decrements in On.Ar and Rt.Ct.Ar suggest a structural disadvantage with age, consistent with postmenopausal bone loss. Age-related patterns in trabecular bone microarchitecture are variable and difficult to explain. Except for Tb.Th, there are no statistically significant relationships with age in women. Men demonstrate significant negative correlations between BV/TV, Tb.N, and age, and a significant positive correlation between Tb.Sp and age. This research highlights sex-specific differences in patterns of age-related bone loss, and provides context for discussion of contemporary South African bone health. While the study sample demonstrates indicators of poor bone quality, osteoporosis research continues to be under-prioritized in South Africa. © 2018 Wiley Periodicals, Inc.

  15. Three-dimensional quantification of structures in trabecular bone using measures of complexity

    DEFF Research Database (Denmark)

    Marwan, Norbert; Kurths, Jürgen; Thomsen, Jesper Skovhus

    2009-01-01

    The study of pathological changes of bone is an important task in diagnostic procedures of patients with metabolic bone diseases such as osteoporosis as well as in monitoring the health state of astronauts during long-term space flights. The recent availability of high-resolution three-dimensiona......The study of pathological changes of bone is an important task in diagnostic procedures of patients with metabolic bone diseases such as osteoporosis as well as in monitoring the health state of astronauts during long-term space flights. The recent availability of high-resolution three......-dimensional (3D) imaging of bone challenges the development of data analysis techniques able to assess changes of the 3D microarchitecture of trabecular bone. We introduce an approach based on spatial geometrical properties and define structural measures of complexity for 3D image analysis. These measures...... evaluate different aspects of organization and complexity of 3D structures, such as complexity of its surface or shape variability. We apply these measures to 3D data acquired by high-resolution microcomputed tomography (µCT) from human proximal tibiae and lumbar vertebrae at different stages...

  16. Effects of low-intensity pulsed ultrasound on new trabecular bone during bone-tendon junction healing in a rabbit model: a synchrotron radiation micro-CT study.

    Directory of Open Access Journals (Sweden)

    Hongbin Lu

    Full Text Available This study was designed to evaluate the effects of low-intensity pulsed ultrasound on bone regeneration during the bone-tendon junction healing process and to explore the application of synchrotron radiation micro computed tomography in three dimensional visualization of the bone-tendon junction to evaluate the microarchitecture of new trabecular bone. Twenty four mature New Zealand rabbits underwent partial patellectomy to establish a bone-tendon junction injury model at the patella-patellar tendon complex. Animals were then divided into low-intensity pulsed ultrasound treatment (20 min/day, 7 times/week and placebo control groups, and were euthanized at week 8 and 16 postoperatively (n = 6 for each group and time point. The patella-patellar tendon specimens were harvested for radiographic, histological and synchrotron radiation micro computed tomography detection. The area of the newly formed bone in the ultrasound group was significantly greater than that of control group at postoperative week 8 and 16. The high resolution three dimensional visualization images of the bone-tendon junction were acquired by synchrotron radiation micro computed tomography. Low-intensity pulsed ultrasound treatment promoted dense and irregular woven bone formation at week 8 with greater bone volume fraction, number and thickness of new trabecular bone but with lower separation. At week 16, ultrasound group specimens contained mature lamellar bone with higher bone volume fraction and thicker trabeculae than that of control group; however, there was no significant difference in separation and number of the new trabecular bone. This study confirms that low-intensity pulsed ultrasound treatment is able to promote bone formation and remodeling of new trabecular bone during the bone-tendon junction healing process in a rabbit model, and the synchrotron radiation micro computed tomography could be applied for three dimensional visualization to quantitatively evaluate

  17. Relationships of the phase velocity with the microarchitectural parameters in bovine trabecular bone in vitro: Application of a stratified model

    Science.gov (United States)

    Lee, Kang Il

    2012-08-01

    The present study aims to provide insight into the relationships of the phase velocity with the microarchitectural parameters in bovine trabecular bone in vitro. The frequency-dependent phase velocity was measured in 22 bovine femoral trabecular bone samples by using a pair of transducers with a diameter of 25.4 mm and a center frequency of 0.5 MHz. The phase velocity exhibited positive correlation coefficients of 0.48 and 0.32 with the ratio of bone volume to total volume and the trabecular thickness, respectively, but a negative correlation coefficient of -0.62 with the trabecular separation. The best univariate predictor of the phase velocity was the trabecular separation, yielding an adjusted squared correlation coefficient of 0.36. The multivariate regression models yielded adjusted squared correlation coefficients of 0.21-0.36. The theoretical phase velocity predicted by using a stratified model for wave propagation in periodically stratified media consisting of alternating parallel solid-fluid layers showed reasonable agreements with the experimental measurements.

  18. A novel use of 3D printing model demonstrates the effects of deteriorated trabecular bone structure on bone stiffness and strength.

    Science.gov (United States)

    Barak, Meir Max; Black, Margaret Arielle

    2018-02-01

    Trabecular bone structure is crucial to normal mechanical behavior of bones. Studies have shown that osteoporosis negatively affects trabecular bone structure, mainly by reducing bone volume fraction (BV/TV) and thus increasing fracture risk. One major limitation in assessing and quantifying the effect of this structural deterioration is that no two trabecular structures are identical. Thus, when we compare a group of healthy bones against a different group of bones that experienced resorption (i.e. decreased BV/TV) we only discover an "average" mechanical effect. It is impossible to quantify the mechanical effect of individual structural deterioration for each sample, simply because we never have the same sample in both states (intact and deteriorated structure). 3D printing is a new technology that can assist in overcoming this issue. Here we report a preliminary study that compares a healthy 3D printed trabecular bone model with the same model after bone resorption was simulated. Since the deteriorated structural bone model is derived from the healthy one, it is possible to directly estimate (percentage wise) the decrease of tissue stiffness and strength as a result of bone resorption for this specific structure. Our results demonstrate that a relatively small decrease in BV/TV (about 8%) leads to a dramatic decrease in structural strength (24%) and structural stiffness (17%), (P printing is a novel and valuable tool for quantifying the effect of structural deterioration on the mechanical properties of trabecular bone. In the future, this approach may help us attain better personal fracture risk assessments by CT scanning, 3D printing and mechanically testing individual bone replicas from patients suffering excessive bone resorption. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Use of MR-based trabecular bone microstructure analysis at the distal radius for osteoporosis diagnostics: a study in post-menopausal women with breast cancer and treated with aromatase inhibitor.

    Science.gov (United States)

    Baum, Thomas; Karampinos, Dimitrios C; Seifert-Klauss, Vanadin; Pencheva, Tsvetelina D; Jungmann, Pia M; Rummeny, Ernst J; Müller, Dirk; Bauer, Jan S

    2016-01-01

    Treatment with aromatase inhibitor (AI) is recommended for post-menopausal women with hormone-receptor positive breast cancer. However, AI therapy is known to induce bone loss leading to osteoporosis with an increased risk for fragility fractures. The purpose of this study was to investigate whether changes of magnetic resonance (MR)-based trabecular bone microstructure parameters as advanced imaging biomarker can already be detected in subjects with AI intake but still without evidence for osteoporosis according to dual energy X-ray absorptiometry (DXA)-based bone mineral density (BMD) measurements as current clinical gold standard. Twenty-one postmenopausal women (62±6 years of age) with hormone-receptor positive breast cancer, ongoing treatment with aromatase inhibitor for 23±15 months, and no evidence for osteoporosis (current DXA T-score greater than -2.5) were recruited for this study. Eight young, healthy women (24±2 years of age) were included as controls. All subjects underwent 3 Tesla magnetic resonance imaging (MRI) of the distal radius to assess the trabecular bone microstructure. Trabecular bone microstructure parameters were not significantly (p>0.05) different between subjects with AI intake and controls, including apparent bone fraction (0.42±0.03 vs. 0.42±0.05), trabecular number (1.95±0.10 mm(-1) vs 1.89±0.15 mm(-1)), trabecular separation (0.30±0.03 mm vs 0.31±0.06 mm), trabecular thickness (0.21±0.01 mm vs 0.22±0.02 mm), and fractal dimension (1.70±0.02 vs. 1.70±0.03). These findings suggest that the initial deterioration of trabecular bone microstructure as measured by MRI and BMD loss as measured by DXA occur not sequentially but rather simultaneously. Thus, the use of MR-based trabecular bone microstructure assessment is limited as early diagnostic biomarker in this clinical setting.

  20. Microdistribution and local dosimetry of 226Ra in trabecular bone of the beagle

    International Nuclear Information System (INIS)

    Polig, E.; Jee, W.S.; Dell, R.B.; Johnson, F.

    1988-01-01

    Sections of lumbar vertebral bodies of young adult beagle dogs have been analyzed autoradiographically to characterize and quantify the local distribution of 226Ra by means of a scanning microscope photometer. The animals received a single injection of 355 kBq/kg body weight and were serially sacrificed at 5 to 1381 days postinjection. Hotspot concentrations decreased from about 51 kBq/g bone at 5 days to 20 kBq/g at 1381 days postinjection. The diffuse concentration changed from 8.3 to 1.9 kBq/g. The mean 226Ra concentration in the trabecular areas scanned was initially higher and at the end of the observation period lower than the average calculated for the whole lumbar vertebral column. Density and area of, and fraction of bone activity in, hotspots virtually remained constant. With time hotspots tended to become translocated into bone volume. Mean dose rates to lining cells from both hotspots and diffuse labels decreased from about 210 mGy/d at early postinjection times to 105 mGy/d. This corresponds to 2.5 to 1.1 times the average skeletal dose rate. A discussion of the level of irradiation in terms of hit frequencies shows that osteoblasts in the initial phase of hotspot formation receive about 60 hits to their nucleus for the duration of bone formation. After about 6 months, however, the 226Ra concentration in new bone and the corresponding hit frequency appears to be low enough that interference with bone formation is unlikely. Morphometric measurements showed that abnormal bone accretion and thickening of trabeculae occurred. This was interpreted as an imbalance between bone formation and resorption. Both formation and resorption seem to be substantially lowered compared to control animals

  1. Lower trabecular volumetric BMD at metaphyseal regions of weight-bearing bones is associated with prior fracture in young girls.

    Science.gov (United States)

    Farr, Joshua N; Tomás, Rita; Chen, Zhao; Lisse, Jeffrey R; Lohman, Timothy G; Going, Scott B

    2011-02-01

    Understanding the etiology of skeletal fragility during growth is critical for the development of treatments and prevention strategies aimed at reducing the burden of childhood fractures. Thus we evaluated the relationship between prior fracture and bone parameters in young girls. Data from 465 girls aged 8 to 13 years from the Jump-In: Building Better Bones study were analyzed. Bone parameters were assessed at metaphyseal and diaphyseal sites of the nondominant femur and tibia using peripheral quantitative computed tomography (pQCT). Dual-energy X-ray absorptiometry (DXA) was used to assess femur, tibia, lumbar spine, and total body less head bone mineral content. Binary logistic regression was used to evaluate the relationship between prior fracture and bone parameters, controlling for maturity, body mass, leg length, ethnicity, and physical activity. Associations between prior fracture and all DXA and pQCT bone parameters at diaphyseal sites were nonsignificant. In contrast, lower trabecular volumetric BMD (vBMD) at distal metaphyseal sites of the femur and tibia was significantly associated with prior fracture. After adjustment for covariates, every SD decrease in trabecular vBMD at metaphyseal sites of the distal femur and tibia was associated with 1.4 (1.1-1.9) and 1.3 (1.0-1.7) times higher fracture prevalence, respectively. Prior fracture was not associated with metaphyseal bone size (ie, periosteal circumference). In conclusion, fractures in girls are associated with lower trabecular vBMD, but not bone size, at metaphyseal sites of the femur and tibia. Lower trabecular vBMD at metaphyseal sites of long bones may be an early marker of skeletal fragility in girls. Copyright © 2011 American Society for Bone and Mineral Research.

  2. A novel composite material specifically developed for ultrasound bone phantoms: cortical, trabecular and skull

    International Nuclear Information System (INIS)

    Wydra, A; Maev, R Gr

    2013-01-01

    In the various stages of developing diagnostic and therapeutic equipment, the use of phantoms can play a very important role in improving the process, help in implementation, testing and calibrations. Phantoms are especially useful in developing new applications and training new doctors in medical schools. However, devices that use different physical factors, such as MRI, Ultrasound, CT Scan, etc will require the phantom to be made of different physical properties. In this paper we introduce the properties of recently designed new materials for developing phantoms for ultrasonic human body investigation, which in today's market make up more than 30% in the world of phantoms. We developed a novel composite material which allows fabrication of various kinds of ultrasound bone phantoms to mimic most of the acoustical properties of human bones. In contrast to the ex vivo tissues, the proposed material can maintain the physical and acoustical properties unchanged for long periods of time; moreover, these properties can be custom designed and created to suit specific needs. As a result, we introduce three examples of ultrasound phantoms that we manufactured in our laboratory: cortical, trabecular and skull bone phantoms. The paper also presents the results of a comparison study between the acoustical and physical properties of actual human bones (reported in the referenced literatures) and the phantoms manufactured by us. (note)

  3. Multiobjective topology optimization of trabecular Bone Structure in the spine and the femur: Implications for biomimcry

    Science.gov (United States)

    Elbanna, Ahmed; Peetz, Darin

    Bone is classically considered to be a self-optimizing structure in accordance with Wolff's law. However, while the structure's ability to adapt to changing stress patterns has been well documented, whether it is fully optimal for compliance is less certain (Sigmund, 2002). Given the complexity of many biological systems, it is expected that this structure serves several purposes. We present a multi-objective topology optimization formulation for trabecular bone in the human body at two locations: the vertebrae and the femur. We account for the effect of different conflicting objectives such as maximization of stiffness, maximization of surface area, and minimization of buckling susceptibility. Our formulation enables us to determine the relative role of each of these objective in optimizing the structure. Moreover, it provides an opportunity to explore what structural features have to evolve to meet a certain objective requirements that may have been absent otherwise. For example, inclusion of stability considerations introduce numerous horizontal and diagonal members in the topology in the case of human vertebrae under vertical loading. However, the stability is found to play a lesser role in the case of the femur bone optimization. Our formulation enables investigation of bone adaptation at different locations of the body as well as under different loading and boundary conditions (e.g. healthy and diseased discs for the case of the spine). We discuss the implications of our findings on developing design rules for bio-inspired and bio-mimetic architectured materials. National Science Foundation: CMMI.

  4. Chitosan nanofiber scaffold improves bone healing via stimulating trabecular bone production due to upregulation of the Runx2/osteocalcin/alkaline phosphatase signaling pathway

    Science.gov (United States)

    Ho, Ming-Hua; Yao, Chih-Jung; Liao, Mei-Hsiu; Lin, Pei-I; Liu, Shing-Hwa; Chen, Ruei-Ming

    2015-01-01

    Osteoblasts play critical roles in bone formation. Our previous study showed that chitosan nanofibers can stimulate osteoblast proliferation and maturation. This translational study used an animal model of bone defects to evaluate the effects of chitosan nanofiber scaffolds on bone healing and the possible mechanisms. In this study, we produced uniform chitosan nanofibers with fiber diameters of approximately 200 nm. A bone defect was surgically created in the proximal femurs of male C57LB/6 mice, and then the left femur was implanted with chitosan nanofiber scaffolds for 21 days and compared with the right femur, which served as a control. Histological analyses revealed that implantation of chitosan nanofiber scaffolds did not lead to hepatotoxicity or nephrotoxicity. Instead, imaging analyses by X-ray transmission and microcomputed tomography showed that implantation of chitosan nanofiber scaffolds improved bone healing compared with the control group. In parallel, microcomputed tomography and bone histomorphometric assays further demonstrated augmentation of the production of new trabecular bone in the chitosan nanofiber-treated group. Furthermore, implantation of chitosan nanofiber scaffolds led to a significant increase in the trabecular bone thickness but a reduction in the trabecular parameter factor. As to the mechanisms, analysis by confocal microscopy showed that implantation of chitosan nanofiber scaffolds increased levels of Runt-related transcription factor 2 (Runx2), a key transcription factor that regulates osteogenesis, in the bone defect sites. Successively, amounts of alkaline phosphatase and osteocalcin, two typical biomarkers that can simulate bone maturation, were augmented following implantation of chitosan nanofiber scaffolds. Taken together, this translational study showed a beneficial effect of chitosan nanofiber scaffolds on bone healing through stimulating trabecular bone production due to upregulation of Runx2-mediated alkaline

  5. Dietary acid load, trabecular bone integrity, and mineral density in an ageing population: the Rotterdam study.

    Science.gov (United States)

    de Jonge, E A L; Koromani, F; Hofman, A; Uitterlinden, A G; Franco, O H; Rivadeneira, F; Kiefte-de Jong, J C

    2017-08-01

    We studied the relation between a diet that is high in acid-forming nutrients (e.g. proteins) and low in base-forming nutrients (e.g. potassium) and bone structure. We showed a negative relation, which was more prominent if proteins were of animal rather than of vegetable origin and if intake of dietary fibre was high. Studies on dietary acid load (DAL) and fractures have shown inconsistent results. Associations between DAL, bone mineral density (BMD) and trabecular bone integrity might play a role in these inconsistencies and might be influenced by renal function and dietary fibre intake. Therefore, our aim was to study (1) associations of DAL with BMD and with the trabecular bone score (TBS) and (2) the potential influence of renal function and dietary fibre in these associations. Dutch individuals aged 45 years and over (n = 4672) participating in the prospective cohort of the Rotterdam study were included. Based on food frequency questionnaires, three indices of DAL were calculated: the net endogenous acid production (NEAP) and the ratios of vegetable or animal protein and potassium (VegPro/K and AnPro/K). Data on lumbar spinal TBS and BMD were derived from dual-energy X-ray absorptiometry measurements. Independent of confounders, NEAP and AnPro/K, but not VegPro/K, were associated with low TBS (standardized β (95%) = -0.04 (-0.07, -0.01) and -0.08 (-0.11, -0.04)) but not with BMD. Associations of AnPro/K and VegPro/K with TBS were non-linear and differently shaped. Unfavourable associations between NEAP, BMD and TBS were mainly present in subgroups with high fibre intake. High NEAP was associated with low TBS. Associations of AnPro/K and VegPro/K and TBS were non-linear and differently shaped. No significant associations of DAL with BMD were observed, nor was there any significant interaction between DAL and renal function. Mainly in participants with high intake of dietary fibre, DAL might be detrimental to bone.

  6. Comparative Analysis of Bone Structural Parameters Reveals Subchondral Cortical Plate Resorption and Increased Trabecular Bone Remodeling in Human Facet Joint Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Cordula Netzer

    2018-03-01

    Full Text Available Facet joint osteoarthritis is a prominent feature of degenerative spine disorders, highly prevalent in ageing populations, and considered a major cause for chronic lower back pain. Since there is no targeted pharmacological therapy, clinical management of disease includes analgesic or surgical treatment. The specific cellular, molecular, and structural changes underpinning facet joint osteoarthritis remain largely elusive. The aim of this study was to determine osteoarthritis-related structural alterations in cortical and trabecular subchondral bone compartments. To this end, we conducted comparative micro computed tomography analysis in healthy (n = 15 and osteoarthritic (n = 22 lumbar facet joints. In osteoarthritic joints, subchondral cortical plate thickness and porosity were significantly reduced. The trabecular compartment displayed a 42 percent increase in bone volume fraction due to an increase in trabecular number, but not trabecular thickness. Bone structural alterations were associated with radiological osteoarthritis severity, mildly age-dependent but not gender-dependent. There was a lack of association between structural parameters of cortical and trabecular compartments in healthy and osteoarthritic specimens. The specific structural alterations suggest elevated subchondral bone resorption and turnover as a potential treatment target in facet joint osteoarthritis.

  7. Bmp2 in osteoblasts of periosteum and trabecular bone links bone formation to vascularization and mesenchymal stem cells

    Science.gov (United States)

    Yang, Wuchen; Guo, Dayong; Harris, Marie A.; Cui, Yong; Gluhak-Heinrich, Jelica; Wu, Junjie; Chen, Xiao-Dong; Skinner, Charles; Nyman, Jeffry S.; Edwards, James R.; Mundy, Gregory R.; Lichtler, Alex; Kream, Barbara E.; Rowe, David W.; Kalajzic, Ivo; David, Val; Quarles, Darryl L.; Villareal, Demetri; Scott, Greg; Ray, Manas; Liu, S.; Martin, James F.; Mishina, Yuji; Harris, Stephen E.

    2013-01-01

    Summary We generated a new Bmp2 conditional-knockout allele without a neo cassette that removes the Bmp2 gene from osteoblasts (Bmp2-cKOob) using the 3.6Col1a1-Cre transgenic model. Bones of Bmp2-cKOob mice are thinner, with increased brittleness. Osteoblast activity is reduced as reflected in a reduced bone formation rate and failure to differentiate to a mature mineralizing stage. Bmp2 in osteoblasts also indirectly controls angiogenesis in the periosteum and bone marrow. VegfA production is reduced in Bmp2-cKOob osteoblasts. Deletion of Bmp2 in osteoblasts also leads to defective mesenchymal stem cells (MSCs), which correlates with the reduced microvascular bed in the periosteum and trabecular bones. Expression of several MSC marker genes (α-SMA, CD146 and Angiopoietin-1) in vivo, in vitro CFU assays and deletion of Bmp2 in vitro in α-SMA+ MSCs support our conclusions. Critical roles of Bmp2 in osteoblasts and MSCs are a vital link between bone formation, vascularization and mesenchymal stem cells. PMID:23843612

  8. The effect of an osteolytic tumor on the three-dimensional trabecular bone morphology in an animal model

    International Nuclear Information System (INIS)

    Kurth, A.A.; Mueller, R.

    2001-01-01

    Objective. To investigate the application of micro-computed tomography (μCT) for the assessment of density differences and deterioration of three-dimensional architecture of trabecular bone in an experimental rat model for tumor- induced osteolytic defects.Design and materials. Walker carcinosarcoma 256 malignant breast cancer cells (W256) were surgically implanted into the medullary canal of the left femur of 15 4-month-old rats. Twenty-eight days after surgery all animals were killed and both femora from each rat were harvested. A total of 30 specimens (left and right femur) were scanned in a desk-top μCT imaging system (μCT 20, Scanco Medical) to assess densitometric and architectural parameters. For each specimen a total of 200 micro-tomographic slices with a resolution of 30 μm in the distal metaphysis was taken. Bone mineral content (BMC) was analyzed for both cortical and trabecular bone (ctBMC), and for trabecular bone only (tBMC). Architectural indices (BV/TV, Tb.N, Tb.Th, Tb.Sp) according to standard definitions used in histomorphometry were calculated for trabecular bone.Results. The quantitative analysis of density parameters revealed significantly (P<0.001) lower values for ctBMC and tBMC in the tumor-bearing group (T) of 26% and 31%, respectively, compared with the contralateral control group. The quantitative analysis revealed significant (P<0.001) changes in the architectural parameters in the tumor-bearing bones compared with the contralateral control group: BV/TV was 30% lower, Tb.N and BS/TV decreased by 24% and 21%, respectively, Tb.Th. decreased by 10% and Tb.Sp. increased by 94%.Conclusions. This study demonstrates that μCT is able to provide three-dimensional parameters of bone mass and trabecular structure in an animal model for tumor-induced bone loss. Recent advances in therapeutic approaches for skeletal diseases such as osteoporosis and metastatic bone disease rely on an understanding of the effects of the agents on the mechanical

  9. [Reproducibility and accuracy in the morphometric and mechanical quantification of trabecular bone from 3 Tesla magnetic resonance images].

    Science.gov (United States)

    Alberich-Bayarri, A; Martí-Bonmatí, L; Sanz-Requena, R; Sánchez-González, J; Hervás Briz, V; García-Martí, G; Pérez, M Á

    2014-01-01

    We used an animal model to analyze the reproducibility and accuracy of certain biomarkers of bone image quality in comparison to a gold standard of computed microtomography (μCT). We used magnetic resonance (MR) imaging and μCT to study the metaphyses of 5 sheep tibiae. The MR images (3 Teslas) were acquired with a T1-weighted gradient echo sequence and an isotropic spatial resolution of 180μm. The μCT images were acquired using a scanner with a spatial resolution of 7.5μm isotropic voxels. In the preparation of the images, we applied equalization, interpolation, and thresholding algorithms. In the quantitative analysis, we calculated the percentage of bone volume (BV/TV), the trabecular thickness (Tb.Th), the trabecular separation (Tb.Sp), the trabecular index (Tb.N), the 2D fractal dimension (D(2D)), the 3D fractal dimension (D(3D)), and the elastic module in the three spatial directions (Ex, Ey and Ez). The morphometric and mechanical quantification of trabecular bone by MR was very reproducible, with percentages of variation below 9% for all the parameters. Its accuracy compared to the gold standard (μCT) was high, with errors less than 15% for BV/TV, D(2D), D(3D), and E(app)x, E(app)y and E(app)z. Our experimental results in animals confirm that the parameters of BV/TV, D(2D), D(3D), and E(app)x, E(app)y and E(app)z obtained by MR have excellent reproducibility and accuracy and can be used as imaging biomarkers for the quality of trabecular bone. Copyright © 2013 SERAM. Published by Elsevier Espana. All rights reserved.

  10. Spontaneous mutation of Dock7 results in lower trabecular bone mass and impaired periosteal expansion in aged female Misty mice.

    Science.gov (United States)

    Le, Phuong T; Bishop, Kathleen A; Maridas, David E; Motyl, Katherine J; Brooks, Daniel J; Nagano, Kenichi; Baron, Roland; Bouxsein, Mary L; Rosen, Clifford J

    2017-12-01

    Misty mice (m/m) have a loss of function mutation in Dock7 gene, a guanine nucleotide exchange factor, resulting in low bone mineral density, uncoupled bone remodeling and reduced bone formation. Dock7 has been identified as a modulator of osteoblast number and in vitro osteogenic differentiation in calvarial osteoblast culture. In addition, m/m exhibit reduced preformed brown adipose tissue innervation and temperature as well as compensatory increase in beige adipocyte markers. While the low bone mineral density phenotype is in part due to higher sympathetic nervous system (SNS) drive in young mice, it is unclear what effect aging would have in mice homozygous for the mutation in the Dock7 gene. We hypothesized that age-related trabecular bone loss and periosteal envelope expansion would be altered in m/m. To test this hypothesis, we comprehensively characterized the skeletal phenotype of m/m at 16, 32, 52, and 78wks of age. When compared to age-matched wild-type control mice (+/+), m/m had lower areal bone mineral density (aBMD) and areal bone mineral content (aBMC). Similarly, both femoral and vertebral BV/TV, Tb.N, and Conn.D were decreased in m/m while there was also an increase in Tb.Sp. As low bone mineral density and decreased trabecular bone were already present at 16wks of age in m/m and persisted throughout life, changes in age-related trabecular bone loss were not observed highlighting the role of Dock7 in controlling trabecular bone acquisition or bone loss prior to 16wks of age. Cortical thickness was also lower in the m/m across all ages. Periosteal and endosteal circumferences were higher in m/m compared to +/+ at 16wks. However, endosteal and periosteal expansion were attenuated in m/m, resulting in m/m having lower periosteal and endosteal circumferences by 78wks of age compared to +/+, highlighting the critical role of Dock7 in appositional bone expansion. Histomorphometry revealed that osteoblasts were nearly undetectable in m/m and marrow

  11. Direct estimation of human trabecular bone stiffness using cone beam computed tomography.

    Science.gov (United States)

    Klintström, Eva; Klintström, Benjamin; Pahr, Dieter; Brismar, Torkel B; Smedby, Örjan; Moreno, Rodrigo

    2018-04-10

    The aim of this study was to evaluate the possibility of estimating the biomechanical properties of trabecular bone through finite element simulations by using dental cone beam computed tomography data. Fourteen human radius specimens were scanned in 3 cone beam computed tomography devices: 3-D Accuitomo 80 (J. Morita MFG., Kyoto, Japan), NewTom 5 G (QR Verona, Verona, Italy), and Verity (Planmed, Helsinki, Finland). The imaging data were segmented by using 2 different methods. Stiffness (Young modulus), shear moduli, and the size and shape of the stiffness tensor were studied. Corresponding evaluations by using micro-CT were regarded as the reference standard. The 3-D Accuitomo 80 (J. Morita MFG., Kyoto, Japan) showed good performance in estimating stiffness and shear moduli but was sensitive to the choice of segmentation method. NewTom 5 G (QR Verona, Verona, Italy) and Verity (Planmed, Helsinki, Finland) yielded good correlations, but they were not as strong as Accuitomo 80 (J. Morita MFG., Kyoto, Japan). The cone beam computed tomography devices overestimated both stiffness and shear compared with the micro-CT estimations. Finite element-based calculations of biomechanics from cone beam computed tomography data are feasible, with strong correlations for the Accuitomo 80 scanner (J. Morita MFG., Kyoto, Japan) combined with an appropriate segmentation method. Such measurements might be useful for predicting implant survival by in vivo estimations of bone properties. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Epiphyseal abnormalities, trabecular bone loss and articular chondrocyte hypertrophy develop in the long bones of postnatal Ext1-deficient mice.

    Science.gov (United States)

    Sgariglia, Federica; Candela, Maria Elena; Huegel, Julianne; Jacenko, Olena; Koyama, Eiki; Yamaguchi, Yu; Pacifici, Maurizio; Enomoto-Iwamoto, Motomi

    2013-11-01

    Long bones are integral components of the limb skeleton. Recent studies have indicated that embryonic long bone development is altered by mutations in Ext genes and consequent heparan sulfate (HS) deficiency, possibly due to changes in activity and distribution of HS-binding/growth plate-associated signaling proteins. Here we asked whether Ext function is continuously required after birth to sustain growth plate function and long bone growth and organization. Compound transgenic Ext1(f/f);Col2CreERT mice were injected with tamoxifen at postnatal day 5 (P5) to ablate Ext1 in cartilage and monitored over time. The Ext1-deficient mice exhibited growth retardation already by 2weeks post-injection, as did their long bones. Mutant growth plates displayed a severe disorganization of chondrocyte columnar organization, a shortened hypertrophic zone with low expression of collagen X and MMP-13, and reduced primary spongiosa accompanied, however, by increased numbers of TRAP-positive osteoclasts at the chondro-osseous border. The mutant epiphyses were abnormal as well. Formation of a secondary ossification center was significantly delayed but interestingly, hypertrophic-like chondrocytes emerged within articular cartilage, similar to those often seen in osteoarthritic joints. Indeed, the cells displayed a large size and round shape, expressed collagen X and MMP-13 and were surrounded by an abundant Perlecan-rich pericellular matrix not seen in control articular chondrocytes. In addition, ectopic cartilaginous outgrowths developed on the lateral side of mutant growth plates over time that resembled exostotic characteristic of children with Hereditary Multiple Exostoses, a syndrome caused by Ext mutations and HS deficiency. In sum, the data do show that Ext1 is continuously required for postnatal growth and organization of long bones as well as their adjacent joints. Ext1 deficiency elicits defects that can occur in human skeletal conditions including trabecular bone loss

  13. Trabecular bone mineral density measured by quantitative CT of the lumbar spine in children and adolescents: reference values and peak bone mass

    International Nuclear Information System (INIS)

    Berthold, L.D.; Alzen, G.; Haras, G.; Mann, M.

    2006-01-01

    Purpose: The aim of this study was to assess bone density values in the trabecular substance of the lumbar vertebral column in children and young adults in Germany from infancy to the age of peak bone mass. Materials and Methods: We performed quantiative computed tomography (QCT) on the first lumbar vertebra in 28 children and adolescents without diseases that may influence bone metabolism (15 boys, 13 girls, mean ages 11 and 8 years, respectively). We also measured 17 healthy young adults (9 men, 8 women, mean ages 20 and 21 years). We used a Somatom Balance Scanner (Siemens, Erlangen) and the Siemens Osteo software. Scan parameters: Slice thickness 1 cm, 80 kV, 81 or 114 mAs. We measured the trabecular bone density and the area and height of the vertebra and calculated the volume and content of calcium hydroxyapatite (Ca-HA) in the trabecular substance of the first lumbar vertebra. Results: Prepubertal boys had a mean bone density of 148.5 (median [med] 150.1, standard deviation [SD] 15.4) mg/Ca-HA per ml bone, and prepubertal girls had a mean density of 149.5 (med 150.8, SD 23.5) mg/ml. We did not observe a difference between prepubertal boys and girls. After puberty there was a significant difference (p<0.001) between males and females: Mean density (male) 158.0, med 162.5, SD 24.0 mg/ml, mean density (female) 191.2, med 191.3, SD 17.7 mg/ml. The Ca-HA content in the trabecular bone of the first lumbar vertebra was 1.1 (med 1.1, SD 0.5) g for prepubertal boys and 1.1 (0.9, 0.4) g for prepubertal girls. For post-pubertal males, the mean Ca-HA content was 3.5 g, med 3.5 SD 0.5 g, and for post-pubertal females, the mean content was 2.8, med 2.7, SD 0.4 g. Conclusion: The normal trabecular bone mineral density is 150 mg/ml with a standard deviation of 20 mg/ml independent of age or gender until the beginning of puberty. Peak bone mass (bone mineral content) in the trabecular substance of the lumbar vertebral column is higher in males than in females, and peak bone

  14. High Insulin Levels in KK-Ay Diabetic Mice Cause Increased Cortical Bone Mass and Impaired Trabecular Micro-Structure

    Directory of Open Access Journals (Sweden)

    Cen Fu

    2015-04-01

    Full Text Available Type 2 diabetes mellitus (T2DM is a chronic disease characterized by hyperglycemia, hyperinsulinemia and complications, including obesity and osteoporosis. Rodents have been widely used to model human T2DM and investigate its effect on the skeleton. We aimed to investigate skeletal alterations in Yellow Kuo Kondo (KK-Ay diabetic mice displaying high insulin and glucose levels. Bone mineral density (BMD, micro-architecture and bone metabolism-related genes were analyzed. The total femoral areal BMD (aBMD, cortical volumetric BMD (vBMD and thickness were significantly increased in KK-Ay mice, while the trabecular vBMD and mineralized bone volume/tissue volume (BV/TV, trabecular thickness and number were decreased compared to C57BL mice. The expression of both osteoblast-related genes, such as osteocalcin (OC, bone sialoprotein, Type I Collagen, osteonectin, RUNX2 and OSX, and osteoclast-related genes, such as TRAP and TCIRG, were up-regulated in KK-Ay mice. Correlation analyses showed that serum insulin levels were positively associated with aBMD, cortical vBMD and thickness and negatively associated with trabecular vBMD and micro-architecture. In addition, serum insulin levels were positively related to osteoblast-related and osteoclast-related gene expression. Our data suggest that high insulin levels in KK-Ay diabetic mice may increase cortical bone mass and impair trabecular micro-structure by up-regulating osteoblast-and osteoclast-related gene expression.

  15. Directional fractal signature methods for trabecular bone texture in hand radiographs: Data from the Osteoarthritis Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Wolski, M., E-mail: marcin.wolski@curtin.edu.au; Podsiadlo, P.; Stachowiak, G. W. [Tribology Laboratory, School of Civil and Mechanical Engineering, Curtin University, Bentley, Western Australia 6102 (Australia)

    2014-08-15

    Purpose: To develop directional fractal signature methods for the analysis of trabecular bone (TB) texture in hand radiographs. Problems associated with the small size of hand bones and the orientation of fingers were addressed. Methods: An augmented variance orientation transform (AVOT) and a quadrant rotating grid (QRG) methods were developed. The methods calculate fractal signatures (FSs) in different directions. Unlike other methods they have the search region adjusted according to the size of bone region of interest (ROI) to be analyzed and they produce FSs defined with respect to any chosen reference direction, i.e., they work for arbitrary orientation of fingers. Five parameters at scales ranging from 2 to 14 pixels (depending on image size and method) were derived from rose plots of Hurst coefficients, i.e., FS in dominating roughness (FS{sub Sta}), vertical (FS{sub V}) and horizontal (FS{sub H}) directions, aspect ratio (StrS), and direction signatures (StdS), respectively. The accuracy in measuring surface roughness and isotropy/anisotropy was evaluated using 3600 isotropic and 800 anisotropic fractal surface images of sizes between 20 × 20 and 64 × 64 pixels. The isotropic surfaces had FDs ranging from 2.1 to 2.9 in steps of 0.1, and the anisotropic surfaces had two dominating directions of 30° and 120°. The methods were used to find differences in hand TB textures between 20 matched pairs of subjects with (cases: approximate Kellgren-Lawrence (KL) grade ≥2) and without (controls: approximate KL grade <2) radiographic hand osteoarthritis (OA). The OA Initiative public database was used and 20 × 20 pixel bone ROIs were selected on 5th distal and middle phalanges. The performance of the AVOT and QRG methods was compared against a variance orientation transform (VOT) method developed earlier [M. Wolski, P. Podsiadlo, and G. W. Stachowiak, “Directional fractal signature analysis of trabecular bone: evaluation of different methods to detect early

  16. Directional fractal signature methods for trabecular bone texture in hand radiographs: Data from the Osteoarthritis Initiative

    International Nuclear Information System (INIS)

    Wolski, M.; Podsiadlo, P.; Stachowiak, G. W.

    2014-01-01

    Purpose: To develop directional fractal signature methods for the analysis of trabecular bone (TB) texture in hand radiographs. Problems associated with the small size of hand bones and the orientation of fingers were addressed. Methods: An augmented variance orientation transform (AVOT) and a quadrant rotating grid (QRG) methods were developed. The methods calculate fractal signatures (FSs) in different directions. Unlike other methods they have the search region adjusted according to the size of bone region of interest (ROI) to be analyzed and they produce FSs defined with respect to any chosen reference direction, i.e., they work for arbitrary orientation of fingers. Five parameters at scales ranging from 2 to 14 pixels (depending on image size and method) were derived from rose plots of Hurst coefficients, i.e., FS in dominating roughness (FS Sta ), vertical (FS V ) and horizontal (FS H ) directions, aspect ratio (StrS), and direction signatures (StdS), respectively. The accuracy in measuring surface roughness and isotropy/anisotropy was evaluated using 3600 isotropic and 800 anisotropic fractal surface images of sizes between 20 × 20 and 64 × 64 pixels. The isotropic surfaces had FDs ranging from 2.1 to 2.9 in steps of 0.1, and the anisotropic surfaces had two dominating directions of 30° and 120°. The methods were used to find differences in hand TB textures between 20 matched pairs of subjects with (cases: approximate Kellgren-Lawrence (KL) grade ≥2) and without (controls: approximate KL grade <2) radiographic hand osteoarthritis (OA). The OA Initiative public database was used and 20 × 20 pixel bone ROIs were selected on 5th distal and middle phalanges. The performance of the AVOT and QRG methods was compared against a variance orientation transform (VOT) method developed earlier [M. Wolski, P. Podsiadlo, and G. W. Stachowiak, “Directional fractal signature analysis of trabecular bone: evaluation of different methods to detect early osteoarthritis

  17. Development and testing of texture discriminators for the analysis of trabecular bone in proximal femur radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Huber, M. B.; Carballido-Gamio, J.; Fritscher, K.; Schubert, R.; Haenni, M.; Hengg, C.; Majumdar, S.; Link, T. M. [Department of Radiology and Biomedical Imaging, University of California, 400 Parnassus Avenue, San Francisco, California 94143 (United States); University of Health Sciences, Medical Informatics and Technology, 6060 Hall (Austria); AO Development Institute, 7270 Davos Platz (Switzerland); Medical University Innsbruck, 6020 Innsbruck (Austria); Department of Radiology and Biomedical Imaging, University of California, 400 Parnassus Avenue, San Francisco, California 94143 (United States)

    2009-11-15

    }=0.61 (MF and MG features, p<0.01) and were partially independent of BMD. The correlations were dependent on the choice of the ROI and the texture measure. The best predictive multiregression model for failure load R{sub adj}{sup 2}=0.86 (p<0.001) included a set of recently developed texture methods (MF and SIM) but excluded bone mineral density and commonly used texture measures. Conclusions: The results suggest that texture information contained in trabecular bone structure visualized on radiographs may predict whether an implant anchorage can be used and may determine the local bone quality from preoperative radiographs.

  18. Development and testing of texture discriminators for the analysis of trabecular bone in proximal femur radiographs

    International Nuclear Information System (INIS)

    Huber, M. B.; Carballido-Gamio, J.; Fritscher, K.; Schubert, R.; Haenni, M.; Hengg, C.; Majumdar, S.; Link, T. M.

    2009-01-01

    and MG features, p adj 2 =0.86 (p<0.001) included a set of recently developed texture methods (MF and SIM) but excluded bone mineral density and commonly used texture measures. Conclusions: The results suggest that texture information contained in trabecular bone structure visualized on radiographs may predict whether an implant anchorage can be used and may determine the local bone quality from preoperative radiographs.

  19. Trabecular bone score as a skeletal fragility index in acromegaly patients.

    Science.gov (United States)

    Hong, A R; Kim, J H; Kim, S W; Kim, S Y; Shin, C S

    2016-03-01

    Lumbar spine trabecular bone score (TBS) was significantly decreased in active acromegaly patients. TBS may be useful to assess the skeletal fragility in acromegaly in which bone mineral density (BMD) is not sufficient to represent bone strength and explain the high incidence of fragility fractures in acromegaly patients. Although the data on BMD are controversial, patients with acromegaly have an increased risk of fragility fracture. We examined the lumbar spine TBS to explain the skeletal deterioration in acromegaly patients. We included 14 men and 19 women acromegaly patients who underwent dual-energy X-ray absorptiometry at the time of diagnosis from 2000 to 2014 at Seoul National University Hospital. Ninety-nine age-, sex- and body mass index-matched controls were recruited. Biochemical parameters, lumbar spine TBS, and BMD at all sites were measured. Gonadal status was evaluated at diagnosis. Lumbar spine TBS was lower in acromegaly patients than in controls in both genders (1.345 ± 0.121 vs. 1.427 ± 0.087, P = 0.005 in men; 1.356 ± 0.082 vs. 1.431 ± 0.071, P = 0.001 in women). In contrast, BMD at all sites did not differ between the two groups. Hypogonadal acromegaly patients (men, n = 9; women, n = 12) had lower TBS values compared with controls both in men and women (all P acromegaly patients, lumbar spine TBS was lower than in women controls only (P = 0.041). Skeletal microarchitecture was deteriorated in acromegaly patients as assessed by TBS, which seems to be a consequence of growth hormone excess as well as hypogonadism, especially in women.

  20. Influence of the pore fluid on the phase velocity in bovine trabecular bone In Vitro: Prediction of the biot model

    Science.gov (United States)

    Lee, Kang Il

    2013-01-01

    The present study aims to investigate the influence of the pore fluid on the phase velocity in bovine trabecular bone in vitro. The frequency-dependent phase velocity was measured in 20 marrow-filled and water-filled bovine femoral trabecular bone samples. The mean phase velocities at frequencies between 0.6 and 1.2 MHz exhibited significant negative dispersions for both the marrow-filled and the water-filled samples. The magnitudes of the dispersions showed no significant differences between the marrow-filled and the water-filled samples. In contrast, replacement of marrow by water led to a mean increase in the phase velocity of 27 m/s at frequencies from 0.6 to 1.2 MHz. The theoretical phase velocities of the fast wave predicted by using the Biot model for elastic wave propagation in fluid-saturated porous media showed good agreements with the measurements.

  1. Protection of trabecular bone in ovariectomized rats by turmeric (Curcuma longa L.) is dependent on extract composition.

    Science.gov (United States)

    Wright, Laura E; Frye, Jennifer B; Timmermann, Barbara N; Funk, Janet L

    2010-09-08

    Extracts prepared from turmeric (Curcuma longa L., [Zingiberaceae]) containing bioactive phenolic curcuminoids were evaluated for bone-protective effects in a hypogonadal rat model of postmenopausal osteoporosis. Three-month female Sprague-Dawley rats were ovariectomized (OVX) and treated with a chemically complex turmeric fraction (41% curcuminoids by weight) or a curcuminoid-enriched turmeric fraction (94% curcuminoids by weight), both dosed at 60 mg/kg 3x per week, or vehicle alone. Effects of two months of treatment on OVX-induced bone loss were followed prospectively by serial assessment of bone mineral density (BMD) of the distal femur using dual-energy X-ray absorptiometry (DXA), while treatment effects on trabecular bone microarchitecture were assessed at two months by microcomputerized tomography (microCT). Chemically complex turmeric did not prevent bone loss, however, the curcuminoid-enriched turmeric prevented up to 50% of OVX-induced loss of trabecular bone and also preserved the number and connectedness of the strut-like trabeculae. These results suggest that turmeric may have bone-protective effects but that extract composition is a critical factor.

  2. Age-related mechanical strength evolution of trabecular bone under fatigue damage for both genders: Fracture risk evaluation.

    Science.gov (United States)

    Ben Kahla, Rabeb; Barkaoui, Abdelwahed; Merzouki, Tarek

    2018-05-04

    Bone tissue is a living composite material, providing mechanical and homeostatic functions, and able to constantly adapt its microstructure to changes in long term loading. This adaptation is conducted by a physiological process, known as "bone remodeling". This latter is manifested by interactions between osteoclasts and osteoblasts, and can be influenced by many local factors, via effects on bone cell differentiation and proliferation. In the current work, age and gender effects on damage rate evolution, throughout life, have been investigated using a mechanobiological finite element modeling. To achieve the aim, a mathematical model has been developed, coupling both cell activities and mechanical behavior of trabecular bone, under cyclic loadings. A series of computational simulations (ABAQUS/UMAT) has been performed on a 3D human proximal femur, allowing to investigate the effects of mechanical and biological parameters on mechanical strength of trabecular bone, in order to evaluate the fracture risk resulting from fatigue damage. The obtained results revealed that mechanical stimulus amplitude affects bone resorption and formation rates, and indicated that age and gender are major factors in bone response to the applied loadings. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Clinical Application of Solid Model Based on Trabecular Tibia Bone CT Images Created by 3D Printer.

    Science.gov (United States)

    Cho, Jaemo; Park, Chan-Soo; Kim, Yeoun-Jae; Kim, Kwang Gi

    2015-07-01

    The aim of this work is to use a 3D solid model to predict the mechanical loads of human bone fracture risk associated with bone disease conditions according to biomechanical engineering parameters. We used special image processing tools for image segmentation and three-dimensional (3D) reconstruction to generate meshes, which are necessary for the production of a solid model with a 3D printer from computed tomography (CT) images of the human tibia's trabecular and cortical bones. We examined the defects of the mechanism for the tibia's trabecular bones. Image processing tools and segmentation techniques were used to analyze bone structures and produce a solid model with a 3D printer. These days, bio-imaging (CT and magnetic resonance imaging) devices are able to display and reconstruct 3D anatomical details, and diagnostics are becoming increasingly vital to the quality of patient treatment planning and clinical treatment. Furthermore, radiographic images are being used to study biomechanical systems with several aims, namely, to describe and simulate the mechanical behavior of certain anatomical systems, to analyze pathological bone conditions, to study tissues structure and properties, and to create a solid model using a 3D printer to support surgical planning and reduce experimental costs. These days, research using image processing tools and segmentation techniques to analyze bone structures to produce a solid model with a 3D printer is rapidly becoming very important.

  4. Tributyltin induces distinct effects on cortical and trabecular bone in female C57Bl/6J mice.

    Science.gov (United States)

    Watt, James; Baker, Amelia H; Meeks, Brett; Pajevic, Paola D; Morgan, Elise F; Gerstenfeld, Louis C; Schlezinger, Jennifer J

    2018-09-01

    The retinoid X receptors (RXR), peroxisome proliferator activated receptor gamma (PPARγ), and liver X receptors (LXR) all have been shown to regulate bone homeostasis. Tributyltin (TBT) is an environmental contaminant that is a dual RXRα/β and PPARγ agonist. TBT induces RXR, PPARγ, and LXR-mediated gene transcription and suppresses osteoblast differentiation in vitro. Bone marrow multipotent mesenchymal stromal cells derived from female C57BL/6J mice were more sensitive to suppression of osteogenesis by TBT than those derived from male mice. In vivo, oral gavage of 12 week old female, C57Bl/6J mice with 10 mg/kg TBT for 10 weeks resulted in femurs with a smaller cross-sectional area and thinner cortex. Surprisingly, TBT induced significant increases in trabecular thickness, number, and bone volume fraction. TBT treatment did not change the Rankl:Opg RNA ratio in whole bone, and histological analyses showed that osteoclasts in the trabecular space were minimally reduced. In contrast, expression of cardiotrophin-1, an osteoblastogenic cytokine secreted by osteoclasts, increased. In primary bone marrow macrophage cultures, TBT marginally inhibited the number of osteoclasts that differentiated, in spite of significantly suppressing expression of osteoclast markers Nfatc1, Acp5, and Ctsk and resorptive activity. TBT induced expression of RXR- and LXR-dependent genes in whole bone and in vitro osteoclast cultures. However, only an RXR antagonist, but not an LXR antagonist, significantly inhibited TBTs ability to suppress osteoclast differentiation. These results suggest that TBT has distinct effects on cortical versus trabecular bone, likely resulting from independent effects on osteoblast and osteoclast differentiation that are mediated through RXR. © 2018 Wiley Periodicals, Inc.

  5. Dipeptidyl Peptidase-4 Inhibitor, Vildagliptin, Improves Trabecular Bone Mineral Density and Microstructure in Obese, Insulin-Resistant, Pre-diabetic Rats.

    Science.gov (United States)

    Charoenphandhu, Narattaphol; Suntornsaratoon, Panan; Sa-Nguanmoo, Piangkwan; Tanajak, Pongpan; Teerapornpuntakit, Jarinthorn; Aeimlapa, Ratchaneevan; Chattipakorn, Nipon; Chattipakorn, Siriporn

    2018-02-02

    Obese insulin resistance and type 2 diabetes mellitus profoundly impair bone mechanical properties and bone quality. However, because several antidiabetes drugs, especially thiazolidinediones, further aggravate bone loss in individuals with diabetes, diabetic osteopathy should not be treated by using simply any glucose-lowering agents. Recently, incretins have been reported to affect osteoblast function positively. The present study aimed to investigate the effects of vildagliptin, an inhibitor of dipeptidyl peptidase-4, on bone of rats with high-fat-diet-induced prediabetes. Male rats were fed a high-fat diet for 12 weeks to induce obese insulin resistance and then treated with vildagliptin for 4 weeks. The effects of the drug on bone were determined by microcomputed tomography and bone histomorphometry. Vildagliptin markedly improved insulin resistance in these obese insulin-resistant rats. It also significantly increased volumetric bone mineral density. Specifically, vildagliptin-treated obese insulin-resistant rats exhibited higher trabecular volumetric bone mineral density than vehicle-treated obese insulin-resistant rats, whereas cortical volumetric bone mineral density, cortical thickness and area were not changed. Bone histomorphometric analysis in a trabecular-rich area (i.e. tibial metaphysis) revealed greater trabecular bone volume and number and less trabecular separation without change in trabecular thickness, osteocyte lacunar area or cortical thickness in the vildagliptin-treated group. Vildagliptin had a beneficial effect on the bone of obese insulin-resistant rats with prediabetes, particularly at the trabecular site. Such benefit probably results from enhanced bone formation rather than from suppressed bone resorption. Copyright © 2018 Diabetes Canada. Published by Elsevier Inc. All rights reserved.

  6. In vitro and in silico characterization of open-cell structures of trabecular bone.

    Science.gov (United States)

    Ramos-Infante, S J; Pérez, M A

    2017-11-01

    This work aimed to perform a detailed in vitro and in silico characterization of open-cell structures, which resemble trabecular bone, to elucidate osteoporosis failure mechanisms. Experimental and image-based computational methods were used to estimate Young's modulus and porosities of different open-cell structures (Sawbones; Malmö, Sweden). Three different open-cell structures with different porosities were characterized. Additionally, some open-cell structures were scanned using a microcomputed tomography system (μCT) to non-destructively predict specimen Young's modulus of the structures by developing voxel-based and tetrahedral finite element (FE) models. A 3D reconstruction and FE analyses were used. The experimental and computational results with different element types (linear and quadratic tetrahedrons and voxel-based meshes) were compared with Sawbones data (Sawbones; Malmö, Sweden) revealing important differences in Young's modulus and porosities. The specimens with high and low volume fractions were best represented by linear and quadratic tetrahedrons, respectively. These results could be used to develop new osteoporosis-prevention strategies.

  7. Ultrasonic characterization of cancellous bone using apparent integrated backscatter

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmeister, B K [Department of Physics, Rhodes College, 2000 North Parkway, Memphis, TN 38112 (United States); III, C I Jones [Department of Physics, Rhodes College, 2000 North Parkway, Memphis, TN 38112 (United States); Caldwell, G J [Department of Physics, Rhodes College, 2000 North Parkway, Memphis, TN 38112 (United States); Kaste, S C [Department of Diagnostic Imaging, St Jude Children' s Research Hospital, Memphis, TN 38105 (United States)

    2006-06-07

    Apparent integrated backscatter (AIB) is a measure of the frequency-averaged (integrated) backscattered power contained in some portion of a backscattered ultrasonic signal. AIB has been used extensively to study soft tissues, but its usefulness as a tissue characterization technique for cancellous bone has not been demonstrated. To address this, we performed measurements on 17 specimens of cancellous bone over two different frequency ranges using a 1 MHz and 5 MHz broadband ultrasonic transducer. Specimens were obtained from bovine tibiae and prepared in the shape of cubes (15 mm side length) with faces oriented along transverse (anterior, posterior, medial and lateral) and longitudinal (superior and inferior) principal anatomic directions. A mechanical scanning system was used to acquire multiple backscatter signals from each direction for each cube. AIB demonstrated highly significant linear correlations with bone mineral density (BMD) for both the transverse (R{sup 2} = 0.817) and longitudinal (R{sup 2} = 0.488) directions using the 5 MHz transducer. In contrast, the correlations with density were much weaker for the 1 MHz transducer (R{sup 2} = 0.007 transverse, R{sup 2} = 0.228 longitudinal). In all cases where a significant correlation was observed, AIB was found to decrease with increasing BMD.

  8. Monte Carlo simulation of age-dependent radiation dose from alpha- and beta-emitting radionuclides to critical trabecular bone and bone marrow targets

    Science.gov (United States)

    Dant, James T.; Richardson, Richard B.; Nie, Linda H.

    2013-05-01

    Alpha (α) particles and low-energy beta (β) particles present minimal risk for external exposure. While these particles can induce leukemia and bone cancer due to internal exposure, they can also be beneficial for targeted radiation therapies. In this paper, a trabecular bone model is presented to investigate the radiation dose from bone- and marrow-seeking α and β emitters to different critical compartments (targets) of trabecular bone for different age groups. Two main issues are addressed with Monte Carlo simulations. The first is the absorption fractions (AFs) from bone and marrow to critical targets within the bone for different age groups. The other issue is the application of 223Ra for the radiotherapy treatment of bone metastases. Both a static model and a simulated bone remodeling process are established for trabecular bone. The results show significantly lower AFs from radionuclide sources in the bone volume to the peripheral marrow and the haematopoietic marrow for adults than for newborns and children. The AFs from sources on the bone surface and in the bone marrow to peripheral marrow and haematopoietic marrow also varies for adults and children depending on the energy of the particles. Regarding the use of 223Ra as a radionuclide for the radiotherapy of bone metastases, the simulations show a significantly higher dose from 223Ra and its progeny in forming bone to the target compartment of bone metastases than that from two other more commonly used β-emitting radiopharmaceuticals, 153Sm and 89Sr. There is also a slightly lower dose from 223Ra in forming bone to haematopoietic marrow than that from 153Sm and 89Sr. These results indicate a higher therapy efficiency and lower marrow toxicity from 223Ra and its progeny. In conclusion, age-related changes in bone dimension and cellularity seem to significantly affect the internal dose from α and β emitters in the bone and marrow to critical targets, and 223Ra may be a more efficient

  9. Connective Tissue Growth Factor reporter mice label a subpopulation of mesenchymal progenitor cells that reside in the trabecular bone region.

    Science.gov (United States)

    Wang, Wen; Strecker, Sara; Liu, Yaling; Wang, Liping; Assanah, Fayekah; Smith, Spenser; Maye, Peter

    2015-02-01

    Few gene markers selectively identify mesenchymal progenitor cells inside the bone marrow. We have investigated a cell population located in the mouse bone marrow labeled by Connective Tissue Growth Factor reporter expression (CTGF-EGFP). Bone marrow flushed from CTGF reporter mice yielded an EGFP+ stromal cell population. Interestingly, the percentage of stromal cells retaining CTGF reporter expression decreased with age in vivo and was half the frequency in females compared to males. In culture, CTGF reporter expression and endogenous CTGF expression marked the same cell types as those labeled using Twist2-Cre and Osterix-Cre fate mapping approaches, which previously had been shown to identify mesenchymal progenitors in vitro. Consistent with this past work, sorted CTGF+ cells displayed an ability to differentiate into osteoblasts, chondrocytes, and adipocytes in vitro and into osteoblast, adipocyte, and stromal cell lineages after transplantation into a parietal bone defect. In vivo examination of CTGF reporter expression in bone tissue sections revealed that it marked cells highly localized to the trabecular bone region and was not expressed in the perichondrium or periosteum. Mesenchymal cells retaining high CTGF reporter expression were adjacent to, but distinct from mature osteoblasts lining bone surfaces and endothelial cells forming the vascular sinuses. Comparison of CTGF and Osterix reporter expression in bone tissue sections indicated an inverse correlation between the strength of CTGF expression and osteoblast maturation. Down-regulation of CTGF reporter expression also occurred during in vitro osteogenic differentiation. Collectively, our studies indicate that CTGF reporter mice selectively identify a subpopulation of bone marrow mesenchymal progenitor cells that reside in the trabecular bone region. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Trabecular bone microstructure is impaired in the proximal femur of human immunodeficiency virus-infected men with normal bone mineral density.

    Science.gov (United States)

    Kazakia, Galateia J; Carballido-Gamio, Julio; Lai, Andrew; Nardo, Lorenzo; Facchetti, Luca; Pasco, Courtney; Zhang, Chiyuan A; Han, Misung; Parrott, Amanda Hutton; Tien, Phyllis; Krug, Roland

    2018-02-01

    There is evidence that human immunodeficiency virus (HIV) infection and antiretroviral therapy (ART) are independent risk factors for osteoporosis and fracture which is not solely explained by changes in bone mineral density. Thus, we hypothesized that the assessment of trabecular microstructure might play an important role for bone quality in this population and might explain the increased fracture risk. In this study, we have assessed bone microstructure in the proximal femur using high-resolution magnetic resonance imaging (MRI) as well as in the extremities using high resolution peripheral quantitative computed tomography (HR-pQCT) in HIV-infected men and healthy controls and compared these findings to those based on areal bone mineral density (aBMD) derived from dual X-ray absorptiometry (DXA) which is the standard clinical parameter for the diagnosis of osteoporosis. Eight HIV-infected men and 11 healthy age-matched controls were recruited and informed consent was obtained before each scan. High-resolution MRI of the proximal femur was performed using fully balanced steady state free precession (bSSFP) on a 3T system. Three volumes of interest at corresponding anatomic locations across all subjects were defined based on registrations of a common template. Four MR-based trabecular microstructural parameters were analyzed at each region: fuzzy bone volume fraction (f-BVF), trabecular number (Tb.N), thickness (Tb.Th), and spacing (Tb.Sp). In addition, the distal radius and distal tibia were imaged with HR-pQCT. Four HR-pQCT-based microstructural parameters were analyzed: trabecular bone volume fraction (BV/TV), Tb.N, Tb.Th, and Tb.Sp. Total hip and spine aBMD were determined from DXA. Microstructural bone parameters derived from MRI at the proximal femur and from HR-pQCT at the distal tibia showed significantly lower bone quality in HIV-infected patients compared to healthy controls. In contrast, DXA aBMD data showed no significant differences between HIV

  11. Trabecular bone microarchitecture analysis, a way for an early detection of genetic dwarfism? Case study of a dwarf mother's offspring.

    Science.gov (United States)

    Colombo, Antony; Hoogland, Menno; Coqueugniot, Hélène; Dutour, Olivier; Waters-Rist, Andrea

    2018-03-01

    A 66 year-old woman with a disproportionate dwarfism and who bore seven children was discovered at the Middenbeemster archaeological site (The Netherlands). Three are perinates and show no macroscopic or radiological evidence for a FGFR3 mutation causing hypo-or achondroplasia. This mutation induces dysfunction of the growth cartilage, leading to abnormalities in the development of trabecular bone. Because the mutation is autosomal dominant, these perinates have a 50% risk of having been affected. This study determines whether trabecular bone microarchitecture (TBMA) analysis is useful for detecting genetic dwarfism. Proximal metaphyses of humeri were μCT-scanned with a resolution of 7-12 μm. Three volumes of interest were segmented from each bone with TIVMI© software. The TBMA was quantified in BoneJ© using six parameters on which a multivariate analysis was then performed. Two of the Middenbeemster perinates show a quantitatively different TBMA organization. These results and the family's medical history suggest a diagnosis of genetic dwarfism for this two perinates. This study provides evidence to support the efficacy of μCT for diagnosing early-stage bone disease. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Axial compressive strength of human vertebrae trabecular bones classified as normal, osteopenic and osteoporotic by quantitative ultrasonometry of calcaneus

    Directory of Open Access Journals (Sweden)

    Reinaldo Cesar

    2017-06-01

    Full Text Available Abstract Introduction Biomechanical assessment of trabecular bone microarchitecture contributes to the evaluation of fractures risk associated with osteoporosis and plays a crucial role in planning preventive strategies. One of the most widely clinical technics used for osteoporosis diagnosis by health professionals is bone dual-energy X-ray absorptiometry (DEXA. However, doubts about its accuracy motivate the introduction of congruent technical analysis such as calcaneal ultrasonometry (Quantitative Ultrasonometry - QUS. Methods Correlations between Bone Quality Index (BQI, determined by calcaneal ultrasonometry of thirty (30 individuals classified as normal, osteopenic and osteoporotic, and elastic modulus (E and ultimate compressive strength (UCS from axial compression tests of ninety (90 proof bodies from human vertebrae trabecular bone, which were extracted from cadavers in the twelfth thoracic region (T12, first and fourth lumbar (L1 and L4. Results Analysis of variance (ANOVA showed significant differences for E (p = 0.001, for UCS (p = 0.0001 and BQI. Spearman’s rank correlation coefficient (rho between BQI and E (r = 0.499 and BQI and UCS (r = 0.508 were moderate. Discussion Calcaneal ultrasonometry technique allowed a moderate estimate of bone mechanical strength and fracture risk associated with osteoporosis in human vertebrae.

  13. Voxel effects within digital images of trabecular bone and their consequences on chord-length distribution measurements

    International Nuclear Information System (INIS)

    Rajon, D.A.; Shah, A.P.; Watchman, C.J.; Bolch, W.E.; Jokisch, D.W.; Patton, P.W.

    2002-01-01

    Chord-length distributions through the trabecular regions of the skeleton have been investigated since the early 1960s. These distributions have become important features for bone marrow dosimetry; as such, current models rely on the accuracy of their measurements. Recent techniques utilize nuclear magnetic resonance (NMR) microscopy to acquire 3D images of trabecular bone that are then used to measure 3D chord-length distributions by Monte Carlo methods. Previous studies have shown that two voxel effects largely affect the acquisition of these distributions within digital images. One is particularly pertinent as it dramatically changes the shape of the distribution and reduces its mean. An attempt was made to reduce this undesirable effect and good results were obtained for a single-sphere model using minimum acceptable chord (MAC) methods (Jokisch et al 2001 Med. Phys. 28 1493-504). The goal of the present work is to extend the study of these methods to more general models in order to better quantify their consequences. First, a mathematical model of a trabecular bone sample was used to test the usefulness of the MAC methods. The results showed that these methods were not efficient for this simulated bone model. These methods were further tested on a single voxelized sphere over a large range of voxel sizes. The results showed that the MAC methods are voxel-size dependent and overestimate the mean chord length for typical resolutions used with NMR microscopy. The study further suggests that bone and marrow chord-length distributions currently utilized in skeletal dosimetry models are most likely affected by voxel effects that yield values of mean chord length lower than their true values. (author)

  14. Adaptations in the Microarchitecture and Load Distribution of Maternal Cortical and Trabecular Bone in Response to Multiple Reproductive Cycles in Rats

    Science.gov (United States)

    de Bakker, Chantal M. J.; Altman-Singles, Allison R.; Li, Yihan; Tseng, Wei-Ju; Li, Connie; Liu, X. Sherry

    2017-01-01

    Pregnancy, lactation, and weaning result in dramatic changes in maternal calcium metabolism. In particular, the increased calcium demand during lactation causes a substantial degree of maternal bone loss. This reproductive bone loss has been suggested to be largely reversible, as multiple clinical studies have found that parity and lactation history have no adverse effect on post-menopausal fracture risk. However, the precise effects of pregnancy, lactation, and post-weaning recovery on maternal bone structure are not well understood. Our study aimed to address this question by longitudinally tracking changes in trabecular and cortical bone microarchitecture at the proximal tibia in rats throughout three cycles of pregnancy, lactation, and post-weaning using in vivo μCT. We found that the trabecular thickness underwent a reversible deterioration during pregnancy and lactation, which was fully recovered after weaning, while other parameters of trabecular microarchitecture (including trabecular number, spacing, connectivity density, and structure model index) underwent a more permanent deterioration which recovered minimally. Thus, pregnancy and lactation resulted in both transient and long-lasting alterations in trabecular microstructure. In the meantime, multiple reproductive cycles appeared to improve the robustness of cortical bone (resulting in an elevated cortical area and polar moment of inertia), as well as increase the proportion of the total load carried by the cortical bone at the proximal tibia. Taken together, changes in the cortical and trabecular compartments suggest that while rat tibial trabecular bone appears to be highly involved in maintaining calcium homeostasis during female reproduction, cortical bone adapts to increase its load-bearing capacity, allowing the overall mechanical function of the tibia to be maintained. PMID:28109138

  15. Radiography of the mandible prior to endosseous implant treatment. Localization of the mandibular canal and assessment of trabecular bone

    International Nuclear Information System (INIS)

    Lindh, C.

    1996-03-01

    Mandibular autopsy specimens were examined with different radiographic techniques in order to evaluate the visibility of the mandibular canal and the measurement accuracy of distances related to the mandibular canal. Hypocycloidal, spiral and computed tomography (CT) were superior to periapical and panoramic radiography in visualizing the mandibular canal. The tomographic techniques were more accurate when measurements of distances related to the mandibular canal were performed. No difference in measurement accuracy was found between the tomographic techniques. Concerning visibility of the mandibular canal, interobserver agreement was lowest for periapical radiography and highest for CT. Intraobserver agreement was moderate or good for all techniques. A high interobserver variation was found for measurability of distances related to the mandibular canal. The trabecular bone tissue in mandibular autopsy specimens was studied concerning different characteristics. A classification system to be used prior to implant treatment, based on the trabecular pattern in periapical radiographs, was proposed. 74 refs

  16. Radiography of the mandible prior to endosseous implant treatment. Localization of the mandibular canal and assessment of trabecular bone

    Energy Technology Data Exchange (ETDEWEB)

    Lindh, C.

    1996-03-01

    Mandibular autopsy specimens were examined with different radiographic techniques in order to evaluate the visibility of the mandibular canal and the measurement accuracy of distances related to the mandibular canal. Hypocycloidal, spiral and computed tomography (CT) were superior to periapical and panoramic radiography in visualizing the mandibular canal. The tomographic techniques were more accurate when measurements of distances related to the mandibular canal were performed. No difference in measurement accuracy was found between the tomographic techniques. Concerning visibility of the mandibular canal, interobserver agreement was lowest for periapical radiography and highest for CT. Intraobserver agreement was moderate or good for all techniques. A high interobserver variation was found for measurability of distances related to the mandibular canal. The trabecular bone tissue in mandibular autopsy specimens was studied concerning different characteristics. A classification system to be used prior to implant treatment, based on the trabecular pattern in periapical radiographs, was proposed. 74 refs.

  17. Is Trabecular Bone Score Valuable in Bone Microstructure Assessment after Gastric Bypass in Women with Morbid Obesity?

    Directory of Open Access Journals (Sweden)

    Agustina Pia Marengo

    2017-12-01

    Full Text Available Introduction: The effects of bariatric surgery on skeletal health raise many concerns. Trabecular bone score (TBS is obtained through the analysis of lumbar spine dual X-ray absorptiometry (DXA images and allows an indirect assessment of skeletal microarchitecture (MA. The aim of our study was to evaluate the changes in bone mineral density (BMD and alterations in bone microarchitecture assessed by TBS in morbidly obese women undergoing Roux-en-Y gastric bypass (RYGB, over a three-year follow-up. Material/Methods: A prospective study of 38 morbidly obese white women, aged 46.3 ± 8.2 years, undergoing RYGB was conducted. Biochemical analyses and DXA scans with TBS evaluation were performed before and at one year and three years after surgery. Results: Patients showed normal calcium and phosphorus plasma concentrations throughout the study. However, 25-hydroxyvitamin D (25(OHD3 decreased, and 71% of patients had a vitamin D deficiency at three years. BMD at femoral neck and lumbar spine (LSBMD significantly decreased 13.53 ± 5.42% and 6.03 ± 6.79%, respectively, during the three-year follow-up; however Z-score values remained above those for women of the same age. TBS was within normal ranges at one and three years (1.431 ± 106 and 1.413 ± 85, respectively, and at the end of the study, 73.7% of patients had normal bone MA. TBS at three years correlated inversely with age (r = −0.41, p = 0.010, body fat (r = −0.465, p = 0.004 and greater body fat deposited in trunk (r = −0.48, p = 0.004, and positively with LSBMD (r = 0.433, p = 0.007, fat mass loss (r = 0.438, p = 0.007 and lean mass loss (r = 0.432, p = 0.008. In the regression analysis, TBS remained associated with body fat (β = −0.625, p = 0.031; R2 = 0.47. The fracture risk, calculated by FRAX® (University of Sheffield, Sheffield, UK, with and without adjustment by TBS, was low. Conclusion: Women undergoing RYGB in the mid-term have a preserved bone MA, assessed by TBS.

  18. Clopidogrel (Plavix®), a P2Y(12) receptor antagonist, inhibits bone cell function in vitro and decreases trabecular bone in vivo

    DEFF Research Database (Denmark)

    Syberg, Susanne; Brandao-Burch, Andrea; Patel, Jessal J

    2012-01-01

    Clopidogrel (Plavix®), a selective P2Y(12) receptor antagonist, is widely prescribed to reduce the risk of heart attack and stroke and acts via the inhibition of platelet aggregation. Accumulating evidence now suggests that extracellular nucleotides, signalling through P2 receptors, play...... a significant role in bone, modulating both osteoblast and osteoclast function. In this study, we investigated the effects of clopidogrel treatment on (1) bone cell formation, differentiation and activity in vitro; and, (2) trabecular and cortical bone parameters in vivo. P2Y(12) receptor expression...

  19. Marked disparity between trabecular and cortical bone loss with age in healthy men. Measurement by vertebral computed tomography and radial photon absorptiometry

    International Nuclear Information System (INIS)

    Meier, D.E.; Orwoll, E.S.; Jones, J.M.

    1984-01-01

    To define age-related changes in bone mineral content in normal men, we measured radial (proximal and distal) and vertebral bone mineral content in 62 men aged 30 to 92 years. Radial bone mineral content (largely cortical bone) was measured by single photon absorptiometry, and trabecular vertebral content (T12, L1 to L3) by computed tomography. Radial bone mineral content fell gradually (2% to 3.4% per decade) with age, but vertebral trabecular content fell more rapidly (12% per decade). Body size was not associated with the rate of bone loss from the distal radial and vertebral sites, but men with lower surface areas lost bone more rapidly at the predominantly cortical proximal radial site. The fact that radial cortical bone mineral content falls much less rapidly than vertebral trabecular content with age and is also associated with surface area indicates that trabecular and cortical bone compartments may be independently modulated. Age-related bone loss should not be considered a homogeneous process

  20. Using Anisotropic 3D Minkowski Functionals for Trabecular Bone Characterization and Biomechanical Strength Prediction in Proximal Femur Specimens

    Science.gov (United States)

    Nagarajan, Mahesh B.; De, Titas; Lochmüller, Eva-Maria; Eckstein, Felix; Wismüller, Axel

    2017-01-01

    The ability of Anisotropic Minkowski Functionals (AMFs) to capture local anisotropy while evaluating topological properties of the underlying gray-level structures has been previously demonstrated. We evaluate the ability of this approach to characterize local structure properties of trabecular bone micro-architecture in ex vivo proximal femur specimens, as visualized on multi-detector CT, for purposes of biomechanical bone strength prediction. To this end, volumetric AMFs were computed locally for each voxel of volumes of interest (VOI) extracted from the femoral head of 146 specimens. The local anisotropy captured by such AMFs was quantified using a fractional anisotropy measure; the magnitude and direction of anisotropy at every pixel was stored in histograms that served as a feature vectors that characterized the VOIs. A linear multi-regression analysis algorithm was used to predict the failure load (FL) from the feature sets; the predicted FL was compared to the true FL determined through biomechanical testing. The prediction performance was measured by the root mean square error (RMSE) for each feature set. The best prediction performance was obtained from the fractional anisotropy histogram of AMF Euler Characteristic (RMSE = 1.01 ± 0.13), which was significantly better than MDCT-derived mean BMD (RMSE = 1.12 ± 0.16, p<0.05). We conclude that such anisotropic Minkowski Functionals can capture valuable information regarding regional trabecular bone quality and contribute to improved bone strength prediction, which is important for improving the clinical assessment of osteoporotic fracture risk. PMID:29170581

  1. Use of dual energy X-ray absorptiometry, the trabecular bone score and quantitative computed tomography in the evaluation of chronic kidney disease-mineral and bone disorders.

    Science.gov (United States)

    Pocock, Nicholas

    2017-03-01

    In subjects with chronic kidney disease (CKD) who suffer a minimal trauma fracture, the problem is to differentiate between osteoporosis and the various forms of renal bone disease associated with CKD-mineral and bone disorder. This problem is exacerbated by the fact that renal osteodystrophy may coexist with osteoporosis. The World Health Organization's bone mineral density (BMD) criteria for osteopenia ( -2.5 < T-score < -1.0) and osteoporosis (a T-score ≤ -2.5) may be used in patients with CKD stages 1-3. In CKD stages 4-5, BMD by dual-energy X-ray absorptiometry (DXA) is less predictive and may underestimate fracture risk. The development of absolute fracture risk (AFR) algorithms, such as FRAX® and the Garvan absolute fracture risk calculator, to predict risk of fracture over a given time (usually 10 years) aims to incorporate non-BMD risk factors into the clinical assessment. FRAX® has been shown to be useful to assess fracture risk in CKD but may underestimate fracture risk in advanced CKD. The trabecular bone score is a measure of grey scale homogeneity obtained from spine DXA, which correlates to trabecular microarchitecture and is an independent risk factor for fracture. Recent data demonstrate the potential utility of the trabecular bone score adjustment of AFR through the FRAX® algorithm in subjects with CKD. Parameters of bone microarchitecture using peripheral quantitative computed tomography (pQCT) or high-resolution pQCT are also able to discriminate fracture status in subjects with CKD. However, there are at present no convincing data that the addition of pQCT or high-resolution pQCT parameters to DXA BMD improves fracture discrimination. More advanced estimates of bone strength derived from measurements of micro-architecture, by QCT-derived finite element analysis may be incorporated into AFR algorithms in the future. © 2017 Asian Pacific Society of Nephrology.

  2. A coherent/Compton scattering method employing an x-ray tube for measurement of trabecular bone mineral content

    International Nuclear Information System (INIS)

    Puumalainen, P.; Uimarihuhta, A.; Olkkonen, H.

    1982-01-01

    Results showed that the x-ray generator could be used as a radiation source in the coherent/Compton scattering method of measuring trabecular bone mineral content. The quasimonoenergetic x-ray beam was produced from the continuous bremsstrahlung radiation with the aid of a spectral filter. Of the two measuring arrangements that were tested, the semiconductor detector geometry appeared to give distinctly more reproducible results than the two NaI detector system. However, to improve the counting efficiency of the coherent radiation, the 'coherent' NaI detector could be replaced by a bore-through scintillation probe (bore diameter about 10mm). By placing the x-ray fluorescence target inside the bore, the yield would be considerably higher. The present method is suitable for TBMC measurements of small animal and human peripheral bones. Errors are discussed in relation to increase of bone size. (U.K.)

  3. Bone ingrowth potential of electron beam and selective laser melting produced trabecular-like implant surfaces with and without a biomimetic coating

    NARCIS (Netherlands)

    Biemond, J.E.; Hannink, G.; Verdonschot, Nicolaas Jacobus Joseph; Buma, P.

    2013-01-01

    The bone ingrowth potential of trabecular-like implant surfaces produced by either selective laser melting (SLM) or electron beam melting (EBM), with or without a biomimetic calciumphosphate coating, was examined in goats. For histological analysis and histomorphometry of bone ingrowth depth and

  4. Machine learning based analytics of micro-MRI trabecular bone microarchitecture and texture in type 1 Gaucher disease.

    Science.gov (United States)

    Sharma, Gulshan B; Robertson, Douglas D; Laney, Dawn A; Gambello, Michael J; Terk, Michael

    2016-06-14

    Type 1 Gaucher disease (GD) is an autosomal recessive lysosomal storage disease, affecting bone metabolism, structure and strength. Current bone assessment methods are not ideal. Semi-quantitative MRI scoring is unreliable, not standardized, and only evaluates bone marrow. DXA BMD is also used but is a limited predictor of bone fragility/fracture risk. Our purpose was to measure trabecular bone microarchitecture, as a biomarker of bone disease severity, in type 1 GD individuals with different GD genotypes and to apply machine learning based analytics to discriminate between GD patients and healthy individuals. Micro-MR imaging of the distal radius was performed on 20 type 1 GD patients and 10 healthy controls (HC). Fifteen stereological and textural measures (STM) were calculated from the MR images. General linear models demonstrated significant differences between GD and HC, and GD genotypes. Stereological measures, main contributors to the first two principal components (PCs), explained ~50% of data variation and were significantly different between males and females. Subsequent PCs textural measures were significantly different between GD patients and HC individuals. Textural measures also significantly differed between GD genotypes, and distinguished between GD patients with normal and pathologic DXA scores. PCA and SVM predictive analyses discriminated between GD and HC with maximum accuracy of 73% and area under ROC curve of 0.79. Trabecular STM differences can be quantified between GD patients and HC, and GD sub-types using micro-MRI and machine learning based analytics. Work is underway to expand this approach to evaluate GD disease burden and treatment efficacy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. A signature dissimilarity measure for trabecular bone texture in knee radiographs

    International Nuclear Information System (INIS)

    Woloszynski, T.; Podsiadlo, P.; Stachowiak, G. W.; Kurzynski, M.

    2010-01-01

    Purpose: The purpose of this study is to develop a dissimilarity measure for the classification of trabecular bone (TB) texture in knee radiographs. Problems associated with the traditional extraction and selection of texture features and with the invariance to imaging conditions such as image size, anisotropy, noise, blur, exposure, magnification, and projection angle were addressed. Methods: In the method developed, called a signature dissimilarity measure (SDM), a sum of earth mover's distances calculated for roughness and orientation signatures is used to quantify dissimilarities between textures. Scale-space theory was used to ensure scale and rotation invariance. The effects of image size, anisotropy, noise, and blur on the SDM developed were studied using computer generated fractal texture images. The invariance of the measure to image exposure, magnification, and projection angle was studied using x-ray images of human tibia head. For the studies, Mann-Whitney tests with significance level of 0.01 were used. A comparison study between the performances of a SDM based classification system and other two systems in the classification of Brodatz textures and the detection of knee osteoarthritis (OA) were conducted. The other systems are based on weighted neighbor distance using compound hierarchy of algorithms representing morphology (WND-CHARM) and local binary patterns (LBP). Results: Results obtained indicate that the SDM developed is invariant to image exposure (2.5-30 mA s), magnification (x1.00-x1.35), noise associated with film graininess and quantum mottle ( 64x64 pixels). However, the measure is sensitive to changes in projection angle (>5 deg.), image anisotropy (>30 deg.), and blur generated by a regular film screen. For the classification of Brodatz textures, the SDM based system produced comparable results to the LBP system. For the detection of knee OA, the SDM based system achieved 78.8% classification accuracy and outperformed the WND

  6. A signature dissimilarity measure for trabecular bone texture in knee radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Woloszynski, T.; Podsiadlo, P.; Stachowiak, G. W.; Kurzynski, M. [Tribology Laboratory, School of Mechanical Engineering, University of Western Australia, Crawley, Western Australia 6009 (Australia); Chair of Computer Systems and Networks, Faculty of Electronics, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland)

    2010-05-15

    Purpose: The purpose of this study is to develop a dissimilarity measure for the classification of trabecular bone (TB) texture in knee radiographs. Problems associated with the traditional extraction and selection of texture features and with the invariance to imaging conditions such as image size, anisotropy, noise, blur, exposure, magnification, and projection angle were addressed. Methods: In the method developed, called a signature dissimilarity measure (SDM), a sum of earth mover's distances calculated for roughness and orientation signatures is used to quantify dissimilarities between textures. Scale-space theory was used to ensure scale and rotation invariance. The effects of image size, anisotropy, noise, and blur on the SDM developed were studied using computer generated fractal texture images. The invariance of the measure to image exposure, magnification, and projection angle was studied using x-ray images of human tibia head. For the studies, Mann-Whitney tests with significance level of 0.01 were used. A comparison study between the performances of a SDM based classification system and other two systems in the classification of Brodatz textures and the detection of knee osteoarthritis (OA) were conducted. The other systems are based on weighted neighbor distance using compound hierarchy of algorithms representing morphology (WND-CHARM) and local binary patterns (LBP). Results: Results obtained indicate that the SDM developed is invariant to image exposure (2.5-30 mA s), magnification (x1.00-x1.35), noise associated with film graininess and quantum mottle (<25%), blur generated by a sharp film screen, and image size (>64x64 pixels). However, the measure is sensitive to changes in projection angle (>5 deg.), image anisotropy (>30 deg.), and blur generated by a regular film screen. For the classification of Brodatz textures, the SDM based system produced comparable results to the LBP system. For the detection of knee OA, the SDM based system

  7. Renin inhibitor aliskiren exerts beneficial effect on trabecular bone by regulating skeletal renin-angiotensin system and kallikrein-kinin system in ovariectomized mice.

    Science.gov (United States)

    Zhang, Y; Wang, L; Song, Y; Zhao, X; Wong, M S; Zhang, W

    2016-03-01

    The skeletal renin-angiotensin system contributes to the development of osteoporosis. The renin inhibitor aliskiren exhibited beneficial effects on trabecular bone of osteoporotic mice, and this action might be mediated through angiotensin and bradykinin receptor pathways. This study implies the potential application of renin inhibitor in the management for postmenopausal osteoporosis. The skeletal renin-angiotensin system plays key role in the pathological process of osteoporosis. The present study is designed to elucidate the effect of renin inhibitor aliskiren on trabecular bone and its potential action mechanism in ovariectomized (OVX) mice. The OVX mice were treated with low dose (5 mg/kg) or high dose (25 mg/kg) of aliskiren or its vehicle for 8 weeks. The bone turnover markers were measured by ELISA. The structural parameters of trabecular bone at lumbar vertebra (LV) and distal femoral metaphysis were measured by micro-CT. The expression of messenger RNA (mRNA) and protein was studied by RT-PCR and immunoblotting, respectively. Aliskiren treatment reduced urinary excretion of calcium and serum level of tartrate-resistant acid phosphatase in OVX mice. The treatment with aliskiren significantly increased bone volume (BV/TV) and connectivity density (Conn.D) of trabecular bone at LV-2 and LV-5 as well as dramatically enhanced BV/TV, Conn.D, bone mineral density (BMD/BV) and decreased bone surface (BS/BV) at the distal femoral end. Aliskiren significantly down-regulated the expression of angiotensinogen, angiotensin II (Ang II), Ang II type 1 receptor, bradykinin receptor (BR)-1, and osteocytic-specific gene sclerostin as well as the osteoclast-specific genes, including carbonic anhydrase II, matrix metalloproteinase-9, and cathepsin K. This study revealed that renin inhibitor aliskiren exhibited the beneficial effects on trabecular bone of ovariectomy-induced osteoporotic mice, and the underlying mechanism for this action might be mediated through Ang II and

  8. A computer-aided system for automatic extraction of femur neck trabecular bone architecture using isotropic volume construction from clinical hip computed tomography images.

    Science.gov (United States)

    Vivekanandhan, Sapthagirivasan; Subramaniam, Janarthanam; Mariamichael, Anburajan

    2016-10-01

    Hip fractures due to osteoporosis are increasing progressively across the globe. It is also difficult for those fractured patients to undergo dual-energy X-ray absorptiometry scans due to its complicated protocol and its associated cost. The utilisation of computed tomography for the fracture treatment has become common in the clinical practice. It would be helpful for orthopaedic clinicians, if they could get some additional information related to bone strength for better treatment planning. The aim of our study was to develop an automated system to segment the femoral neck region, extract the cortical and trabecular bone parameters, and assess the bone strength using an isotropic volume construction from clinical computed tomography images. The right hip computed tomography and right femur dual-energy X-ray absorptiometry measurements were taken from 50 south-Indian females aged 30-80 years. Each computed tomography image volume was re-constructed to form isotropic volumes. An automated system by incorporating active contour models was used to segment the neck region. A minimum distance boundary method was applied to isolate the cortical and trabecular bone components. The trabecular bone was enhanced and segmented using trabecular enrichment approach. The cortical and trabecular bone features were extracted and statistically compared with dual-energy X-ray absorptiometry measured femur neck bone mineral density. The extracted bone measures demonstrated a significant correlation with neck bone mineral density (r > 0.7, p computed tomography images scanned with low dose could eventually be helpful in osteoporosis diagnosis and its treatment planning. © IMechE 2016.

  9. Validation of a measuring technique with computed tomography for cement penetration into trabecular bone underneath the tibial tray in total knee arthroplasty on a cadaver model

    International Nuclear Information System (INIS)

    Verburg, Hennie; Ridder, Laurens C van de; Verhoeven, Vincent WJ; Pilot, Peter

    2014-01-01

    In total knee arthroplasty (TKA), cement penetration between 3 and 5 mm beneath the tibial tray is required to prevent loosening of the tibia component. The objective of this study was to develop and validate a reliable in vivo measuring technique using CT imaging to assess cement distribution and penetration depth in the total area underneath a tibia prosthesis. We defined the radiodensity ranges for trabecular tibia bone, polymethylmethacrylate (PMMA) cement and cement-penetrated trabecular bone and measured the percentages of cement penetration at various depths after cementing two tibia prostheses onto redundant femoral heads. One prosthesis was subsequently removed to examine the influence of the metal tibia prostheses on the quality of the CT images. The percentages of cement penetration in the CT slices were compared with percentages measured with photographs of the corresponding transversal slices. Trabecular bone and cement-penetrated trabecular bone had no overlap in quantitative scale of radio-density. There was no significant difference in mean HU values when measuring with or without the tibia prosthesis. The percentages of measured cement-penetrated trabecular bone in the CT slices of the specimen were within the range of percentages that could be expected based on the measurements with the photographs (p = 0.04). CT scan images provide valid results in measuring the penetration and distribution of cement into trabecular bone underneath the tibia component of a TKA. Since the proposed method does not turn metal elements into artefacts, it enables clinicians to assess the width and density of the cement mantle in vivo and to compare the results of different cementing methods in TKA

  10. Influence of estrogen deficiency and tibolone therapy on trabecular and cortical bone evaluated by computed radiography system in rats

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Ana Carolina Bergmann de; Henriques, Helene Nara [Postgraduate Program in Pathology, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Fernandes, Gustavo Vieira Oliveira [Postgraduate Program in Medical Sciences, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Lima, Inaya; Oliveira, Davi Ferreira de; Lopes, Ricardo Tadeu [Nuclear Engineering Program, Federal University of Rio de Janeiro (UFRJ), RJ (Brazil); Pantaleao, Jose Augusto Soares [Maternal and Child Department, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Granjeiro, Jose Mauro [Department of Cellular and Molecular Biology, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Silva, Maria Angelica Guzman [Department of Pathology, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil)

    2012-03-15

    Purpose: To verify the effects of tibolone administration on trabecular and cortical bone of ovariectomized female rats by computed radiography system (CRS). Methods: The experiment was performed on two groups of rats previously ovariectomized, one received tibolone (OVX+T) while the other did not (OVX), those groups were compared to a control group (C) not ovariectomized. Tibolone administration (1 mg/day) began thirty days after the ovariectomy and the treatment remained for five months. At last, the animals were euthanized and femurs and tibias collected. Computed radiographs of the bones were obtained and the digital images were used to determine the bone optical density and cortical thickness on every group. All results were statistically evaluated with significance set at P<0.05%. Results: Tibolone administration was shown to be beneficial only in the densitometric analysis of the femoral head, performing higher optical density compared to OVX. No difference was found in cortical bone thickness. Conclusion: Ovariectomy caused bone loss in the analyzed regions and tibolone administered in high doses over a long period showed not to be fully beneficial, but preserved bone mass in the femoral head. (author)

  11. Identification of a constitutive law for trabecular bone samples under remodeling in the framework of irreversible thermodynamics

    Science.gov (United States)

    Louna, Zineeddine; Goda, Ibrahim; Ganghoffer, Jean-François

    2018-01-01

    We construct in the present paper constitutive models for bone remodeling based on micromechanical analyses at the scale of a representative unit cell (RUC) including a porous trabecular microstructure. The time evolution of the microstructure is simulated as a surface remodeling process by relating the surface growth remodeling velocity to a surface driving force incorporating a (surface) Eshelby tensor. Adopting the framework of irreversible thermodynamics, a 2D constitutive model based on the setting up of the free energy density and a dissipation potential is identified from FE simulations performed over a unit cell representative of the trabecular architecture obtained from real bone microstructures. The static and evolutive effective properties of bone at the scale of the RUC are obtained by combining a methodology for the evaluation of the average kinematic and static variables over a prototype unit cell and numerical simulations with controlled imposed first gradient rates. The formulated effective growth constitutive law at the scale of the homogenized set of trabeculae within the RUC is of viscoplastic type and relates the average growth strain rate to the homogenized stress tensor. The postulated model includes a power law function of an effective stress chosen to depend on the first and second stress invariants. The model coefficients are calibrated from a set of virtual testing performed over the RUC subjected to a sequence of loadings. Numerical simulations show that overall bone growth does not show any growth kinematic hardening. The obtained results quantify the strength and importance of different types of external loads (uniaxial tension, simple shear, and biaxial loading) on the overall remodeling process and the development of elastic deformations within the RUC.

  12. The combined effects of soya isoflavones and resistant starch on equol production and trabecular bone loss in ovariectomised mice.

    Science.gov (United States)

    Tousen, Yuko; Matsumoto, Yu; Matsumoto, Chiho; Nishide, Yoriko; Nagahata, Yuya; Kobayashi, Isao; Ishimi, Yoshiko

    2016-07-01

    Equol is a metabolite of the soya isoflavone (ISO) daidzein that is produced by intestinal microbiota. Equol has greater oestrogenic activity compared with other ISO, and it prevents bone loss in postmenopausal women. Resistant starch (RS), which has a prebiotic activity and is a dietary fibre, was reported to promote equol production. Conversely, the intestinal microbiota is reported to directly regulate bone health by reducing inflammatory cytokine levels and T-lymphocytes in bone. The present study evaluated the combined effects of diet supplemented with ISO and RS on intestinal microbiota, equol production, bone mineral density (BMD) and inflammatory gene expression in the bone marrow of ovariectomised (OVX) mice. Female ddY strain mice, aged 8 weeks, were either sham-operated (Sham, n 7) or OVX. OVX mice were randomly divided into the following four groups (seven per group): OVX control (OVX); OVX fed 0·05 % ISO diet (OVX+ISO); OVX fed 9 % RS diet (OVX+RS); and OVX fed 0·05 % ISO- and 9 % RS diet (OVX+ISO+RS). After 6 weeks, treatment with the combination of ISO and RS increased equol production, prevented the OVX-induced decline in trabecular BMD in the distal femur by modulating the enteric environment and altered OVX-induced inflammation-related gene expression in the bone marrow. However, there were no significant differences in bone parameters between the ISO+RS and ISO-alone groups in OVX mice. Our findings suggest that the combination of ISO and RS might alter intestinal microbiota and immune status in the bone marrow, resulting in attenuated bone resorption in OVX mice.

  13. Relationships of the phase velocity with the micro architectural parameters in bovine trabecular bone in vitro: application of a stratified model

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang Il [Kangwon National University, Chuncheon (Korea, Republic of)

    2012-08-15

    The present study aims to provide insight into the relationships of the phase velocity with the micro architectural parameters in bovine trabecular bone in vitro. The frequency-dependent phase velocity was measured in 22 bovine femoral trabecular bone samples by using a pair of transducers with a diameter of 25.4 mm and a center frequency of 0.5 MHz. The phase velocity exhibited positive correlation coefficients of 0.48 and 0.32 with the ratio of bone volume to total volume and the trabecular thickness, respectively, but a negative correlation coefficient of -0.62 with the trabecular separation. The best univariate predictor of the phase velocity was the trabecular separation, yielding an adjusted squared correlation coefficient of 0.36. The multivariate regression models yielded adjusted squared correlation coefficients of 0.21 - 0.36. The theoretical phase velocity predicted by using a stratified model for wave propagation in periodically stratified media consisting of alternating parallel solid-fluid layers showed reasonable agreements with the experimental measurements.

  14. Relationships of the phase velocity with the micro architectural parameters in bovine trabecular bone in vitro: application of a stratified model

    International Nuclear Information System (INIS)

    Lee, Kang Il

    2012-01-01

    The present study aims to provide insight into the relationships of the phase velocity with the micro architectural parameters in bovine trabecular bone in vitro. The frequency-dependent phase velocity was measured in 22 bovine femoral trabecular bone samples by using a pair of transducers with a diameter of 25.4 mm and a center frequency of 0.5 MHz. The phase velocity exhibited positive correlation coefficients of 0.48 and 0.32 with the ratio of bone volume to total volume and the trabecular thickness, respectively, but a negative correlation coefficient of -0.62 with the trabecular separation. The best univariate predictor of the phase velocity was the trabecular separation, yielding an adjusted squared correlation coefficient of 0.36. The multivariate regression models yielded adjusted squared correlation coefficients of 0.21 - 0.36. The theoretical phase velocity predicted by using a stratified model for wave propagation in periodically stratified media consisting of alternating parallel solid-fluid layers showed reasonable agreements with the experimental measurements.

  15. Radiation dose to trabecular bone marrow stem cells from 3H, 14C and selected α-emitters incorporated in a bone remodeling compartment

    International Nuclear Information System (INIS)

    Nie Huiling; Richardson, Richard B

    2009-01-01

    A Monte Carlo simulation of repeated cubic units representing trabecular bone cavities in adult bone was employed to determine absorbed dose fractions evaluated for 3 H, 14 C and a set of α-emitters incorporated within a bone remodeling compartment (BRC). The BRC consists of a well-oxygenated vascular microenvironment located within a canopy of bone-lining cells. The International Commission on Radiological Protection (ICRP) considers that an important target for radiation-induced bone cancer is the endosteum marrow layer adjacent to bone surface where quiescent bone stem cells reside. It is proposed that the active stem cells and progenitor cells located above the BRC canopy, the 'BRC stem cell niche', is a more important radiation-induced cancer target volume. Simulation results from a static model, where no remodeling occurs, indicate that the mean dose from bone and bone surface to the 50 μm quiescent bone stem cell niche, the current ICRP target, was substantially lower (two to three times lower) than that to the narrower and hypoxic 10 μm endosteum for 3 H, 14 C and α-particles with energy range 0.5-10 MeV. The results from a dynamic model indicate that the temporal α-radiation dose to active stem/progenitor cells located in the BRC stem cell niche from the material incorporated in and buried by forming bone was 9- to 111-fold greater than the dose to the quiescent bone stem cell niche. This work indicates that the remodeling portion of the bone surface, rather than the quiescent (endosteal) surface, has the greatest risk of radiation-induced bone cancer, particularly from short-range radiation, due to the elevated dose and the radiosensitizing oxygen effect.

  16. Trabecular bone mineral density measured by quantitative CT of the lumbar spine in children and adolescents: reference values and peak bone mass; Trabekulaere Knochendichte der Lendenwirbelsaeule bei Kindern und Jugendlichen in der quantitativen CT: Referenzwerte und Peak Bone Mass

    Energy Technology Data Exchange (ETDEWEB)

    Berthold, L.D.; Alzen, G. [Kinderradiologie, Zentrum fuer Radiologie, Universitaetsklinikum Giessen und Marburg GmbH, Standort Giessen (Germany); Haras, G. [Siemens AG, Medical Solutions, Forchheim (Germany); Mann, M. [AG Medizinische Statistik, Universitaetsklinikum Giessen und Marburg GmbH, Standort Giessen (Germany)

    2006-12-15

    Purpose: The aim of this study was to assess bone density values in the trabecular substance of the lumbar vertebral column in children and young adults in Germany from infancy to the age of peak bone mass. Materials and Methods: We performed quantiative computed tomography (QCT) on the first lumbar vertebra in 28 children and adolescents without diseases that may influence bone metabolism (15 boys, 13 girls, mean ages 11 and 8 years, respectively). We also measured 17 healthy young adults (9 men, 8 women, mean ages 20 and 21 years). We used a Somatom Balance Scanner (Siemens, Erlangen) and the Siemens Osteo software. Scan parameters: Slice thickness 1 cm, 80 kV, 81 or 114 mAs. We measured the trabecular bone density and the area and height of the vertebra and calculated the volume and content of calcium hydroxyapatite (Ca-HA) in the trabecular substance of the first lumbar vertebra. Results: Prepubertal boys had a mean bone density of 148.5 (median [med] 150.1, standard deviation [SD] 15.4) mg/Ca-HA per ml bone, and prepubertal girls had a mean density of 149.5 (med 150.8, SD 23.5) mg/ml. We did not observe a difference between prepubertal boys and girls. After puberty there was a significant difference (p<0.001) between males and females: Mean density (male) 158.0, med 162.5, SD 24.0 mg/ml, mean density (female) 191.2, med 191.3, SD 17.7 mg/ml. The Ca-HA content in the trabecular bone of the first lumbar vertebra was 1.1 (med 1.1, SD 0.5) g for prepubertal boys and 1.1 (0.9, 0.4) g for prepubertal girls. For post-pubertal males, the mean Ca-HA content was 3.5 g, med 3.5 SD 0.5 g, and for post-pubertal females, the mean content was 2.8, med 2.7, SD 0.4 g. Conclusion: The normal trabecular bone mineral density is 150 mg/ml with a standard deviation of 20 mg/ml independent of age or gender until the beginning of puberty. Peak bone mass (bone mineral content) in the trabecular substance of the lumbar vertebral column is higher in males than in females, and peak bone

  17. Age-related changes of vertical and horizontal lumbar vertebral trabecular 3D bone microstructure is different in women and men.

    Science.gov (United States)

    Thomsen, Jesper Skovhus; Niklassen, Andreas Steenholt; Ebbesen, Ebbe Nils; Brüel, Annemarie

    2013-11-01

    The study presents a 3D method for subdividing a trabecular network into horizontal and vertical oriented bone. This method was used to investigate the age related changes of the bone volume fraction and thickness of horizontal and vertical trabeculae in human lumbar vertebral bone estimated with unbiased 3D methods in women and men over a large age-range. The study comprised second lumbar vertebral body bone samples from 40 women (aged 21.7-96.4years, median 56.6years) and 39 men (aged 22.6-94.6years, median 55.6years). The bone samples were μCT scanned and the 3D microstructure was quantified. A voxel based algorithm inspecting the local neighborhood is presented and used to segment the trabecular network into horizontal and vertical oriented bone. For both women and men BV/TV decreased significantly with age, Tb.Th* was independent of age, while SMI increased significantly with age. Vertical (BV.vert/TV) and horizontal (BV.horz/TV) bone volume fraction decreased significantly with age for both sexes. BV.vert/TV decreased significantly faster with age for women than for men. Vertical (Tb.Th*.vert) and horizontal (Tb.Th*.horz) trabecular thickness were independent of age, while Tb.Th*.horz/Tb.Th*.vert decreased significantly with age for both sexes. Additionally, the 95th percentile of the trabecular thickness distribution increased significantly with age for vertical trabeculae in women, whereas it was independent of age in men. In conclusion, we have shown that vertical and horizontal oriented bone density decreases with age in both women and men, and that vertical oriented bone is lost more quickly in women than in men. Furthermore, vertical and horizontal trabecular thickness were independent of age, whereas the horizontal to vertical trabecular thickness ratio decreased significantly with age indicating a relatively more pronounced thinning of horizontal trabeculae. Finally, the age-related loss of trabecular elements appeared to result in a compensatory

  18. Assessment of bone mineral density by DXA and the trabecular microarchitecture of the calcaneum by texture analysis in pre- and postmenopausal women in the evaluation of osteoporosis

    Directory of Open Access Journals (Sweden)

    Karunanithi R

    2007-01-01

    Full Text Available The in vivo evaluation of trabecular bone structure could be useful in the diagnosis of osteoporosis for the characterization of therapeutic response and understanding the role of parameters other than bone mineral density (BMD in defining skeletal status. This study was made to evaluate changes taking place in the trabecular architecture of bone with age and menopausal status in women. The findings are compared with the femoral neck bone as well as the trochantar bone mineral density determined by dual energy X-ray absorptiometry (DXA, which is a standard reference test for evaluation of osteoporosis. Seventy females were recruited for the study, 25 pre-menopausal (mean age ± SD: 39.4 ± 3.8 and 45 postmenopausal (mean age ± SD: 57.9 ± 7.9 women. The right femoral neck bone mineral density was measured for them by dual energy X-ray absorptiometry (DXA. For the same individuals, lateral view radiographs of the right calcaneum were taken as well. The radiographs were digitized and the region of interest (ROI of 256 x 256 pixels was selected, the run-length matrix was computed for calculating seven parameters [Table 1] and the two-dimensional fast Fourier transform of the image was calculated. Using the FFT, the power spectral density (PSD was derived and the root mean square (RMS value was determined. Our results confirm that age has a significant influence on the texture of the trabecular bone and bone mineral density.

  19. Trabecular bone strains around a dental implant and associated micromotions--a micro-CT-based three-dimensional finite element study.

    Science.gov (United States)

    Limbert, Georges; van Lierde, Carl; Muraru, O Luiza; Walboomers, X Frank; Frank, Milan; Hansson, Stig; Middleton, John; Jaecques, Siegfried

    2010-05-07

    The first objective of this computational study was to assess the strain magnitude and distribution within the three-dimensional (3D) trabecular bone structure around an osseointegrated dental implant loaded axially. The second objective was to investigate the relative micromotions between the implant and the surrounding bone. The work hypothesis adopted was that these virtual measurements would be a useful indicator of bone adaptation (resorption, homeostasis, formation). In order to reach these objectives, a microCT-based finite element model of an oral implant implanted into a Berkshire pig mandible was developed along with a robust software methodology. The finite element mesh of the 3D trabecular bone architecture was generated from the segmentation of microCT scans. The implant was meshed independently from its CAD file obtained from the manufacturer. The meshes of the implant and the bone sample were registered together in an integrated software environment. A series of non-linear contact finite element (FE) analyses considering an axial load applied to the top of the implant in combination with three sets of mechanical properties for the trabecular bone tissue was devised. Complex strain distribution patterns are reported and discussed. It was found that considering the Young's modulus of the trabecular bone tissue to be 5, 10 and 15GPa resulted in maximum peri-implant bone microstrains of about 3000, 2100 and 1400. These results indicate that, for the three sets of mechanical properties considered, the magnitude of maximum strain lies within an homeostatic range known to be sufficient to maintain/form bone. The corresponding micro-motions of the implant with respect to the bone microstructure were shown to be sufficiently low to prevent fibrous tissue formation and to favour long-term osseointegration. Copyright 2010 Elsevier Ltd. All rights reserved.

  20. Trabecular bone strains around a dental implant and associated micromotions--a micro-CT-based three-dimensional finite element study.

    NARCIS (Netherlands)

    Limbert, G.; Lierde, C. van; Muraru, O.L.; Walboomers, X.F.; Frank, M.; Hansson, S.; Middleton, J.; Jaecques, S.

    2010-01-01

    The first objective of this computational study was to assess the strain magnitude and distribution within the three-dimensional (3D) trabecular bone structure around an osseointegrated dental implant loaded axially. The second objective was to investigate the relative micromotions between the

  1. Increased trabecular bone and improved biomechanics in an osteocalcin-null rat model created by CRISPR/Cas9 technology

    Directory of Open Access Journals (Sweden)

    Laura J. Lambert

    2016-10-01

    Full Text Available Osteocalcin, also known as bone γ-carboxyglutamate protein (Bglap, is expressed by osteoblasts and is commonly used as a clinical marker of bone turnover. A mouse model of osteocalcin deficiency has implicated osteocalcin as a mediator of changes to the skeleton, endocrine system, reproductive organs and central nervous system. However, differences between mouse and human osteocalcin at both the genome and protein levels have challenged the validity of extrapolating findings from the osteocalcin-deficient mouse model to human disease. The rat osteocalcin (Bglap gene locus shares greater synteny with that of humans. To further examine the role of osteocalcin in disease, we created a rat model with complete loss of osteocalcin using the CRISPR/Cas9 system. Rat osteocalcin was modified by injection of CRISPR/Cas9 mRNA into the pronuclei of fertilized single cell Sprague-Dawley embryos, and animals were bred to homozygosity and compound heterozygosity for the mutant alleles. Dual-energy X-ray absorptiometry (DXA, glucose tolerance testing (GTT, insulin tolerance testing (ITT, microcomputed tomography (µCT, and a three-point break biomechanical assay were performed on the excised femurs at 5 months of age. Complete loss of osteocalcin resulted in bones with significantly increased trabecular thickness, density and volume. Cortical bone volume and density were not increased in null animals. The bones had improved functional quality as evidenced by an increase in failure load during the biomechanical stress assay. Differences in glucose homeostasis were observed between groups, but there were no differences in body weight or composition. This rat model of complete loss of osteocalcin provides a platform for further understanding the role of osteocalcin in disease, and it is a novel model of increased bone formation with potential utility in osteoporosis and osteoarthritis research.

  2. Assessment of Cortical and Trabecular Bone Changes in Two Models of Post-Traumatic Osteoarthritis

    Science.gov (United States)

    Pauly, Hannah M; Larson, Blair E; Coatney, Garrett A; Button, Keith D.; DeCamp, Charlie E; Fajardo, Ryan S; Haut, Roger C; Donahue, Tammy L Haut

    2015-01-01

    Subchondral bone is thought to play a significant role in the initiation and progression of the post-traumatic osteoarthritis. The goal of this study was to document changes in tibial and femoral subchondral bone that occur as a result of two lapine models of anterior cruciate ligament injury, a modified ACL transection model and a closed-joint traumatic compressive impact model. Twelve weeks post-injury bones were scanned via micro-computed tomography. The subchondral bone of injured limbs from both models showed decreases in bone volume and bone mineral density. Surgical transection animals showed significant bone changes primarily in the medial hemijoint of femurs and tibias, while significant changes were noted in both the medial and lateral hemijoints of both bones for traumatic impact animals. It is believed that subchondral bone changes in the medial hemijoint were likely caused by compromised soft tissue structures seen in both models. Subchondral bone changes in the lateral hemijoint of traumatic impact animals are thought to be due to transmission of the compressive impact force through the joint. The joint-wide bone changes shown in the traumatic impact model were similar to clinical findings from studies investigating the progression of osteoarthritis in humans. PMID:26147652

  3. Pregnant ewes exposed to multiple endocrine disrupting pollutants through sewage sludge-fertilized pasture show an anti-estrogenic effect in their trabecular bone

    Energy Technology Data Exchange (ETDEWEB)

    Lind, P. Monica, E-mail: Monica.Lind@medsci.uu.se [Department of Medical Sciences, Occupational and Environmental Medicine, Uppsala University, Ullerakersvaegen 40, 751 85 Uppsala (Sweden); Oberg, Denise [Department of Environmental Toxicology, Uppsala University, Uppsala (Sweden); Larsson, Sune [Department of Orthopaedics, Uppsala University, Uppsala (Sweden); Kyle, Carol E. [Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB15 8QH (United Kingdom); Orberg, Jan [Department of Environmental Toxicology, Uppsala University, Uppsala (Sweden); Rhind, Stewart M. [Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB15 8QH (United Kingdom)

    2010-05-01

    Pregnant ewes were maintained on pastures fertilized, twice yearly, with either sewage sludge (2.25 tonnes dry matter/ha; Treated; T) or inorganic fertilizer containing equivalent amounts of nitrogen (Control; C), to determine effects on maternal and fetal bone structures, density and mechanical properties of exposure to environmental concentrations of multiple endocrine disrupting compounds (EDCs) and heavy metal pollutants. The ewes were maintained on the respective pastures from the age of about 8 months until they were 4-6 years of age and they were slaughtered at 110 d gestation. Metaphyseal parts of adult ewe femurs exhibited a significantly reduced mean, total cross sectional area (CSA, - 4%; p < 0.05), lower trabecular bone mineral content (BMC, mg/mm; - 18%; p < 0.05), trabecular bone mineral density (BMD, mg/cm{sup 3}, - 8.0%; p < 0.05) and trabecular CSA, mm{sup 2}, - 11.1%; p < 0.05) in T compared with C animals. Femurs of T ewes were stronger than those of C ewes but this may reflect greater body weights. At the mid-diaphyseal part of the fetal bones, there was a reduction in endosteal circumference (- 6.7%, p < 0.05) and marrow cavity area (- 13.8%, p < 0.05) in the female T fetuses compared with female C fetuses. In the male fetuses the mid-diaphyseal part total bone mineral content was higher (+ 3.0%, p < 0.05) in T than in C animals. No treatment difference in biomechanical bending was detected in the fetuses. It is concluded that ewes grazing pasture fertilized with sewage sludge exhibited an anti-estrogenic effect on their trabecular bone in the form of reduced mineral content and density, despite increased body weight. It is suggested that human exposure to low levels of multiple EDCs may have implications for bone structure and human health.

  4. The Orientation of Nanoscale Apatite Platelets in Relation to Osteoblastic-Osteocyte Lacunae on Trabecular Bone Surface.

    Science.gov (United States)

    Shah, Furqan A; Zanghellini, Ezio; Matic, Aleksandar; Thomsen, Peter; Palmquist, Anders

    2016-02-01

    The orientation of nanoscale mineral platelets was quantitatively evaluated in relation to the shape of lacunae associated with partially embedded osteocytes (osteoblastic-osteocytes) on the surface of deproteinised trabecular bone of adult sheep. By scanning electron microscopy and image analysis, the mean orientation of mineral platelets at the osteoblastic-osteocyte lacuna (Ot.Lc) floor was found to be 19° ± 14° in the tibia and 20° ± 14° in the femur. Further, the mineral platelets showed a high degree of directional coherency: 37 ± 7% in the tibia and 38 ± 9% in the femur. The majority of Ot.Lc in the tibia (69.37%) and the femur (74.77%) exhibited a mean orientation of mineral platelets between 0° and 25°, with the largest fraction within a 15°-20° range, 17.12 and 19.8% in the tibia and femur, respectively. Energy dispersive X-ray spectroscopy and Raman spectroscopy were used to characterise the features observed on the anorganic bone surface. The Ca/P (atomic %) ratio was 1.69 ± 0.1 within the Ot.Lc and 1.68 ± 0.1 externally. Raman spectra of NaOCl-treated bone showed peaks associated with carbonated apatite: ν1, ν2 and ν4 PO4(3-), and ν1 CO3(2-), while the collagen amide bands were greatly reduced in intensity compared to untreated bone. The apatite-to-collagen ratio increased considerably after deproteinisation; however, the mineral crystallinity and the carbonate-to-phosphate ratios were unaffected. The ~19°-20° orientation of mineral platelets in at the Ot.Lc floor may be attributable to a gradual rotation of osteoblasts in successive layers relative to the underlying surface, giving rise to the twisted plywood-like pattern of lamellar bone.

  5. Magnetic resonance imaging of trabecular and cortical bone in mice: comparison of high resolution in vivo and ex vivo MR images with corresponding histology

    International Nuclear Information System (INIS)

    Weber, Michael H.; Sharp, Jonathan C.; Latta, Peter; Sramek, Milos; Hassard, H. Thomas; Orr, F. William

    2005-01-01

    Measurements of bone morphometry and remodeling have been shown to reflect bone strength and can be used to diagnose degenerative bone disease. In this study, in vivo and ex vivo magnetic resonance imaging (MRI) techniques to assess trabecular and cortical bone properties have been compared to each other and to histology as a novel means for the quantification of bone. Femurs of C57Bl/6 mice were examined both in vivo and ex vivo on an 11.7 T MRI scanner, followed by histologic processing and morphometry. A thresholding analysis technique was applied to the MRI images to generate contour lines and to delineate the boundaries between bone and marrow. Using MRI, an optimal correlation with histology was obtained with an in vivo longitudinal sectioned short echo time gradient-echo versus an in vivo long echo time spin-echo sequence or an ex vivo pulse sequence. Gradient-echo images were acquired with a maximum in-plane resolution of 35 μm. Our results demonstrated that in both the in vivo and ex vivo data sets, the percent area of marrow increases and percent area of trabecular bone and cortical bone thickness decreases moving from the epiphyseal growth plate to the diaphysis. These changes, observed with MRI, correlate with the histological data. Investigations using in vivo MRI gradient-echo sequences consistently gave the best correlation with histology. Our quantitative evaluation using both ex vivo and in vivo MRI was found to be an effective means to visualize non-invasively the normal variation in trabecular and cortical bone as compared to a histological 'gold standard' The experiments validated in vivo MRI as a potential high resolution technique for investigating both soft tissue, such as marrow, and bone without radiation exposure

  6. Assessment of lumbar trabecular bone density by means of single energy quantitative CT in hospital control children and bone metabolic disorders, 1

    International Nuclear Information System (INIS)

    Nakano, Kazutoshi; Miyamoto, Akie; Imai, Kaoru; Mochizuki, Yumiko; Hayashi, Kitami; Mitsuishi, Yoichi; Fukuyama, Yukio; Kohno, Atsushi; Shigeta, Teiko

    1990-01-01

    We studied the 3rd lumbar vertebral trabecular bone mineral density in 59 cross-sectional pictures of quantitative computed tomography (QCT) with CaCO 3 phantom for 28 hospital control children and 30 cases of suspected bone metabolic disorders. The QCT value of bone mineral density of control children showed neither age dependency nor sexual difference before puberty: for males was 221.8±30.2 mg CaCO 3 /cm 3 (Mean±SD) under 4 years, 218.1±39.7 at 5∼9 years and 217.2±30.9 at 10∼15 years; and for females 220.9±18.3 under 4 years and 240.0±29.4 at 5∼9 years. The QCT values of bone mineral density in bed-ridden patients, children receiving glucocorticoids, and children receiving anticonvulsants were significantly lower than that in control children (p<0.005). The QCT value of bone mineral density of bed-ridden patients was significantly lower than that of children receiving glucocorticoids and of children receiving anticonvulsants (p<0.05, p<0.005 respectively). Our study confirmed that single energy quantitative CT was very useful in pediatric clinical application. (author)

  7. Assessment of lumbar trabecular bone density by means of single energy quantitative CT in hospital control children and bone metabolic disorders, 1

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Kazutoshi; Miyamoto, Akie; Imai, Kaoru; Mochizuki, Yumiko; Hayashi, Kitami; Mitsuishi, Yoichi; Fukuyama, Yukio; Kohno, Atsushi; Shigeta, Teiko (Tokyo Women' s Medical Coll. (Japan))

    1990-03-01

    We studied the 3rd lumbar vertebral trabecular bone mineral density in 59 cross-sectional pictures of quantitative computed tomography (QCT) with CaCO{sub 3} phantom for 28 hospital control children and 30 cases of suspected bone metabolic disorders. The QCT value of bone mineral density of control children showed neither age dependency nor sexual difference before puberty: for males was 221.8{plus minus}30.2 mg CaCO{sub 3}/cm{sup 3} (Mean{plus minus}SD) under 4 years, 218.1{plus minus}39.7 at 5{approx}9 years and 217.2{plus minus}30.9 at 10{approx}15 years; and for females 220.9{plus minus}18.3 under 4 years and 240.0{plus minus}29.4 at 5{approx}9 years. The QCT values of bone mineral density in bed-ridden patients, children receiving glucocorticoids, and children receiving anticonvulsants were significantly lower than that in control children (p<0.005). The QCT value of bone mineral density of bed-ridden patients was significantly lower than that of children receiving glucocorticoids and of children receiving anticonvulsants (p<0.05, p<0.005 respectively). Our study confirmed that single energy quantitative CT was very useful in pediatric clinical application. (author).

  8. A novel registration-based methodology for prediction of trabecular bone fabric from clinical QCT: A comprehensive analysis.

    Directory of Open Access Journals (Sweden)

    Vimal Chandran

    Full Text Available Osteoporosis leads to hip fractures in aging populations and is diagnosed by modern medical imaging techniques such as quantitative computed tomography (QCT. Hip fracture sites involve trabecular bone, whose strength is determined by volume fraction and orientation, known as fabric. However, bone fabric cannot be reliably assessed in clinical QCT images of proximal femur. Accordingly, we propose a novel registration-based estimation of bone fabric designed to preserve tensor properties of bone fabric and to map bone fabric by a global and local decomposition of the gradient of a non-rigid image registration transformation. Furthermore, no comprehensive analysis on the critical components of this methodology has been previously conducted. Hence, the aim of this work was to identify the best registration-based strategy to assign bone fabric to the QCT image of a patient's proximal femur. The normalized correlation coefficient and curvature-based regularization were used for image-based registration and the Frobenius norm of the stretch tensor of the local gradient was selected to quantify the distance among the proximal femora in the population. Based on this distance, closest, farthest and mean femora with a distinction of sex were chosen as alternative atlases to evaluate their influence on bone fabric prediction. Second, we analyzed different tensor mapping schemes for bone fabric prediction: identity, rotation-only, rotation and stretch tensor. Third, we investigated the use of a population average fabric atlas. A leave one out (LOO evaluation study was performed with a dual QCT and HR-pQCT database of 36 pairs of human femora. The quality of the fabric prediction was assessed with three metrics, the tensor norm (TN error, the degree of anisotropy (DA error and the angular deviation of the principal tensor direction (PTD. The closest femur atlas (CTP with a full rotation (CR for fabric mapping delivered the best results with a TN error of 7

  9. The assessment of Trabecular bone score to improve the sensitivity of FRAX in patients with type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Tatiana O. Yalochkina

    2017-12-01

    Full Text Available Aim. To estimate the trabecular bone score (TBS for evaluation of fracture probability in order to make decisions about starting osteoporosis treatment in patients with type 2 diabetes mellitus (T2DM. Materials and methods. We obtained the bone mineral density (BMD and trabecular bone score (TBS using dual energy X-ray absorptiometry (iDXA in patients with T2DM (with and without a history of osteoporotic fractures versus the control group. Before and after TBS measurements we assessed the ten-year probability of fracture using the Fracture Risk Assessment Tool (FRAX. Results. We enrolled 48 patients with T2DM, including 17 with a history of low-traumatic fracture, 31 patients without fractures and 29 subjects of a control group. BMD was higher in patients with T2DM compared to the control group at L1–L4 (mean T-score 0.44, 95% CI -3.2 – 4.9 vs mean T-score 0.33, 95% CI -2.9 – 3.0 in a control group p=0.052 and Total Hip (mean T-score 0.51, 95% CI -2.1 – 3.0 vs mean T-score -0.03, 95% CI -1.4 – 1.2 in a control group p=0,025. The TBS and 10-year probability of fracture (FRAX was not different in patients with T2DM versus the control group. However, when the TBS was entered as an additional risk factor, the 10-year probability of fracture became higher in patients with T2DM (10-year probability of fracture in T2DM- 8.68, 95% CI 0.3-25.0 versus 6.68, 95% CI 0.4–15.0 in control group, p=0.04. Among patients with diabetes with and without fractures the FRAX score was higher in subjects with fractures, but no difference was found in regards to BMD or TBS. Entering BMD and TBS values into the FRAX tool in subjects with diabetes and fractures decreased the FRAX score. However, patients with low-traumatic fractures should be treated for osteoporosis without a BMD, TBS or FRAX assessment. Conclusion. TBS improves the results of FRAX assessment in patients with T2DM and should be entered while evaluating FRAX in patients with T2DM. However

  10. Intratrabecular distribution of tissue stiffness and mineralization in developing trabecular bone

    NARCIS (Netherlands)

    Mulder, L.; Koolstra, J.H.; Toonder, den J.M.J.; Eijden, van T.M.G.J.

    2007-01-01

    The purpose of this study was to investigate the relation between bone tissue stiffness and degree of mineralization distribution and to examine possible changes during prenatal development. Understanding this may provide insight into adaptation processes and into deformation mechanisms of the bone

  11. Apparently normal accumulation in the patellae on bone scintigraphy

    International Nuclear Information System (INIS)

    Kato, Katsuhiko; Ikeda, Mitsuru; Tadokoro, Masanori; Yoshida, Kiyo; Kobayashi, Hidetoshi; Ishigaki, Takeo

    1997-01-01

    In the present study, we examined the influences of gender and ages on accumulation in the patellae on scintigram. The subjects were 828 patients who underwent bone scintigraphy during the past one and half years at the Department of Radiology, Nagoya University Hospital. Patients younger than 20 years old and those with abnormality of the patellae were excluded. The degree of accumulation in the patellae was evaluated using the A-P whole body scintigraphy in comparison with accumulation at the diaphysis of the femur and classified to two categories, ''Positive'' (higher accumulation than that of the diaphysis of the femur) and ''Negative'' (equal or lower than that of the diaphysis of the femur). In general, the degree of accumulation was higher in females than in males. In both males and females, the degree of accumulation increased with age. A difference between the two sides in the degree of accumulation in the patellae was observed in 32% of subjects. The results of this study may serve as basic data for the interpretation of bone scintigrams. (author)

  12. Three-dimensional quantitative CT of the proximal femur: Relationship to vertebral trabecular bone density

    International Nuclear Information System (INIS)

    Bhasin, S.; Zlatkin, M.B.; Sartoris, D.J.; Andre, M.; Resnick, D.

    1987-01-01

    Integrated cancellous, cortical, and total bone density in the femoral neck and inter-trochanteric region was measured bilaterally in 25 women aged 35-90 years (mean age, 65). Contiguous-section (1-cm-thick) data were analyzed using three-dimensional histogram software on a Cemax 1000 image processor. Single-section quantitative CT was used to determine mean mineral equivalent values for vertebral cancellous bone from T-11 to L-3 in each woman. Significant correlation was found between cancellous bone density at the two sites. Cortical and total bone densities in the proximal femur were predicted less well with vertebral cancellous data, suggesting a greater dependence on weight-bearing and activity factors

  13. Reduced bone formation markers, and altered trabecular and cortical bone mineral densities of non-paretic femurs observed in rats with ischemic stroke: A randomized controlled pilot study.

    Directory of Open Access Journals (Sweden)

    Karen N Borschmann

    Full Text Available Immobility and neural damage likely contribute to accelerated bone loss after stroke, and subsequent heightened fracture risk in humans.To investigate the skeletal effect of middle cerebral artery occlusion (MCAo stroke in rats and examine its utility as a model of human post-stroke bone loss.Twenty 15-week old spontaneously hypertensive male rats were randomized to MCAo or sham surgery controls. Primary outcome: group differences in trabecular bone volume fraction (BV/TV measured by Micro-CT (10.5 micron istropic voxel size at the ultra-distal femur of stroke affected left legs at day 28. Neurological impairments (stroke behavior and foot-faults and physical activity (cage monitoring were assessed at baseline, and days 1 and 27. Serum bone turnover markers (formation: N-terminal propeptide of type 1 procollagen, PINP; resorption: C-terminal telopeptide of type 1 collagen, CTX were assessed at baseline, and days 7 and 27.No effect of stroke was observed on BV/TV or physical activity, but PINP decreased by -24.5% (IQR -34.1, -10.5, p = 0.046 at day 27. In controls, cortical bone volume (5.2%, IQR 3.2, 6.9 and total volume (6.4%, IQR 1.2, 7.6 were higher in right legs compared to left legs, but these side-to-side differences were not evident in stroke animals.MCAo may negatively affect bone formation. Further investigation of limb use and physical activity patterns after MCAo is required to determine the utility of this current model as a representation of human post-stroke bone loss.

  14. Morphobiochemical diagnosis of acute trabecular microfractures using gamma correction Tc-99m HDP pinhole bone scan with histopathological verification.

    Science.gov (United States)

    Bahk, Yong-Whee; Hwang, Seok-Ha; Lee, U-Young; Chung, Yong-An; Jung, Joo-Young; Jeong, Hyeonseok S

    2017-11-01

    We prospectively performed gamma correction pinhole bone scan (GCPBS) and histopathologic verification study to make simultaneous morphobiochemical diagnosis of trabecular microfractures (TMF) occurred in the femoral head as a part of femoral neck fracture.Materials consisted of surgical specimens of the femoral head in 6 consecutive patients. The specimens were imaged using Tc-99m hydroxymethylene diphosphonate (HDP) pinhole scan and processed by the gamma correction. After cleansing with 10% formalin solution, injured specimen surface was observed using a surgical microscope to record TMF. Morphological findings shown in the photograph, naive pinhole bone scan, GCPBS, and hematoxylin-eosin (H&E) stain of the specimen were reciprocally correlated for histological verification and the usefulness of suppression and enhancement of Tc-99m HDP uptake was biochemically investigated in TMF and edema and hemorrhage using gamma correction.On the one hand, GCPBS was able to depict the calcifying calluses in TMF with enhanced Tc-99m HDP uptake. They were pinpointed, speckled, round, ovoid, rod-like, geographic, and crushed in shape. The smallest callus measured was 0.23 mm in this series. On the other hand, GCPBS biochemically was able to discern the calluses with enhanced high Tc-99m HDP uptake from the normal and edema dipped and hemorrhage irritated trabeculae with washed out uptake.Morphobiochemically, GCPBS can clearly depict microfractures in the femoral head produced by femoral neck fracture. It discerns the microcalluses with enhanced Tc-99m HDP uptake from the intact and edema dipped and hemorrhage irritated trabeculae with suppressed washed out Tc-99m HDP uptake. Both conventional pinhole bone scan and gamma correction are useful imaging means to specifically diagnose the microcalluses naturally formed in TMF.

  15. Reproducibility of trabecular bone score with different scan modes using dual-energy X-ray absorptiometry: a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Bandirali, Michele; Messina, Carmelo [Universita degli Studi di Milano, Scuola di Specializzazione in Radiodiagnostica, Milano (Italy); Di Leo, Giovanni [Unita di Radiologia, IRCCS Policlinico San Donato, San Donato Milanese (Italy); Pastor Lopez, Maria Juana; Ulivieri, Fabio M. [Servizio di Medicina Nucleare, Ospedale Maggiore, Mineralometria Ossea Computerizzata e Ambulatorio Malattie Metabolismo Minerale e Osseo, Milano (Italy); Mai, Alessandro [Universita degli Studi di Milano, Tecniche di Radiologia Medica, per Immagini e Radioterapia, Milano (Italy); Sardanelli, Francesco [Unita di Radiologia, IRCCS Policlinico San Donato, San Donato Milanese (Italy); Universita degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, San Donato Milanese (Italy)

    2014-08-12

    The trabecular bone score (TBS) accounts for the bone microarchitecture and is calculated on dual-energy X-ray absorptiometry (DXA). We estimated the reproducibility of the TBS using different scan modes compared to the reproducibility bone mineral density (BMD). A spine phantom was used with a Hologic QDR-Discovery A densitometer. For each scan mode [fast array, array, high definition (HD)], 25 scans were automatically performed without phantom repositioning; a further 25 scans were performed with phantom repositioning. For each scan, the TBS was obtained. The coefficient of variation (CoV) was calculated as the ratio between standard deviation and mean; percent least significant change (LSC%) as 2.8 x CoV; reproducibility as the complement to 100 % of LSC%. Differences among scan modes were assessed using ANOVA. Without phantom repositioning, the mean TBS (mm{sup -1}) was: 1.352 (fast array), 1.321 (array), and 1.360 (HD); with phantom repositioning, it was 1.345, 1.332, and 1.362, respectively. Reproducibility of the TBS without phantom repositioning was 97.7 % (fast array), 98.3 % (array), and 98.2 % (HD); with phantom repositioning, it was 97.9 %, 98.7 %, and 98.4 %, respectively. LSC% was ≤2.26 %. Differences among scan modes were all statistically significant (p ≤ 0.019). Reproducibility of BMD was 99.1 % with all scan modes, while LSC% was from 0.86 % to 0.91 %. Reproducibility error of the TBS was 2-3-fold higher than that of BMD. Although statistically significant, differences in TBS among scan modes were within the highest LSC%. Thus, the three scan modes can be considered interchangeable. (orig.)

  16. Prediction of Local Ultimate Strain and Toughness of Trabecular Bone Tissue by Raman Material Composition Analysis

    Directory of Open Access Journals (Sweden)

    Roberto Carretta

    2015-01-01

    Full Text Available Clinical studies indicate that bone mineral density correlates with fracture risk at the population level but does not correlate with individual fracture risk well. Current research aims to better understand the failure mechanism of bone and to identify key determinants of bone quality, thus improving fracture risk prediction. To get a better understanding of bone strength, it is important to analyze tissue-level properties not influenced by macro- or microarchitectural factors. The aim of this pilot study was to identify whether and to what extent material properties are correlated with mechanical properties at the tissue level. The influence of macro- or microarchitectural factors was excluded by testing individual trabeculae. Previously reported data of mechanical parameters measured in single trabeculae under tension and bending and its compositional properties measured by Raman spectroscopy was evaluated. Linear and multivariate regressions show that bone matrix quality but not quantity was significantly and independently correlated with the tissue-level ultimate strain and postyield work (r=0.65–0.94. Principal component analysis extracted three independent components explaining 86% of the total variance, representing elastic, yield, and ultimate components according to the included mechanical parameters. Some matrix parameters were both included in the ultimate component, indicating that the variation in ultimate strain and postyield work could be largely explained by Raman-derived compositional parameters.

  17. Curcumin reduces trabecular and cortical bone in naive and Lewis lung carcinoma-bearing mice

    Science.gov (United States)

    The present study investigated the effects of dietary supplementation with curcumin on bone microstructural changes in female C57BL/6 mice in the presence or absence of Lewis lung carcinoma. Morphometric analysis showed that in tumor-bearing mice curcumin at 2% and 4% dietary levels (w/w) significa...

  18. Curcumin deteriorates trabecular and cortical bone in mice bearing metastatic Lewis lung carcinoma

    Science.gov (United States)

    Bone is a major target of metastasis for many malignancies; curcumin has been studied for its role in cancer prevention including early phase clinical trials for its efficacy and safe use with cancer patients. The present study investigated the effects of dietary supplementation with curcumin (2% a...

  19. A decreased subchondral trabecular bone tissue elastic modulus is associated with pre-arthritic cartilage damage

    DEFF Research Database (Denmark)

    Day, J; Ding, Ming; van der Linden, JC

    2001-01-01

    determined using a combination of finite element models and mechanical testing. The bone tissue modulus was reduced by 60% in the medial condyle of the cases with cartilage damage compared to the control specimens. Neither the presence of cartilage damage nor the anatomic site (medial vs. lateral) affected...

  20. Dietary acid load, trabecular bone integrity, and mineral density in an ageing population: the Rotterdam study

    NARCIS (Netherlands)

    E.A.L. de Jonge (Ester); F. Koromani (Fjorda); A. Hofman (Albert); A.G. Uitterlinden (André); O.H. Franco (Oscar); F. Rivadeneira Ramirez (Fernando); J.C. Kiefte-de Jong (Jessica)

    2017-01-01

    textabstractSummary: We studied the relation between a diet that is high in acid-forming nutrients (e.g. proteins) and low in base-forming nutrients (e.g. potassium) and bone structure. We showed a negative relation, which was more prominent if proteins were of animal rather than of vegetable origin

  1. Study of bony trabecular characteristics using bone morphometry and micro-CT

    International Nuclear Information System (INIS)

    Song, Young Han; Lee, Wan; Lee, Chang Jin; Ji, Jung Hyun; Lee, Byung Do

    2007-01-01

    The research was done to investigate the effectiveness of 2D bony morphometry and microstructure of micro-computed tomography (micro-CT) on the osteoporotic bony change. We performed the bone morphometric analysis of proximal femur in ovariectomized rabbits with BMD and micro-CT examination. Twenty-one female (Newzeland, about 16 weeks old, 2.9-3.4 kg) rabbits were used. Three rabbits were sacrificed on the day when experiment began (Basline). The remaining 18 rabbits were divided into two groups. One group was ovariectomized bilaterally (OVX) and the other animals were subjected to sham operation (Sham). Bone specimens were obtained from the right and left femur of sacrificed rabbits. At intervals of 1,2,3,5,6 months respectively, BMD tests were performed on the proximal on the proximal femur by using PIXImus 2 (GE Lunar Co. USA), 2-dimensional bone morphometric analysis by custom computer program and 2D / 3D bone structure analysis by micro-CT (Skyscan1072, Antwerpen, Belgium). Statistical analysis was carried out for the correlation between bone morphometry, micro-CT and BMD. BV/TV, Tb.Th, Tb.N of micro-CT parameters showed higher values in sham group than OVX group. N.Nd/Ar.RI, N.NdNd, N.NdTm, N. TmTm, PmB/Ar.RI, 3-D BoxSlope of 2D morphometric parameters showed higher values in Sham group than OVX group. The micro-CT parameters of Tb.Sp. Tb.N were statistically significant correlated with BMD respectively. Several 2D morphometric parameters were statistically significant correlated with BMD respectively. Several parameters of 2D bony morphometry and micro-CT showed effective aspects on the osteoporotic bony change

  2. Association of Trabecular Bone Score with Inflammation and Adiposity in Patients with Psoriasis: Effect of Adalimumab Therapy

    Directory of Open Access Journals (Sweden)

    José L. Hernández

    2016-01-01

    Full Text Available Studies on trabecular bone score (TBS in psoriasis are lacking. We aim to assess the association between TBS and inflammation, metabolic syndrome features, and serum adipokines in 29 nondiabetic patients with psoriasis without arthritis, before and after 6-month adalimumab therapy. For that purpose, adjusted partial correlations and stepwise multivariable linear regression analysis were performed. No correlation was found between TBS and disease severity. TBS was negatively associated with weight, BMI, waist perimeter, fat percentage, and systolic and diastolic blood pressure before and after adalimumab. After 6 months of therapy, a negative correlation between TBS and insulin resistance (p=0.02 and leptin (p=0.01 and a positive correlation with adiponectin were found (p=0.01. The best set of predictors for TBS values at baseline were female sex (p=0.015, age (p=0.05, and BMI (p=0.001. The best set of predictors for TBS following 6 months of biologic therapy were age (p=0.001, BMI (p<0.0001, and serum adiponectin levels (p=0.027. In conclusion, in nondiabetic patients with moderate-to-severe psoriasis, TBS correlates with metabolic syndrome features and inflammation. This association is still present after 6 months of adalimumab therapy. Moreover, serum adiponectin levels seem to be an independent variable related to TBS values, after adalimumab therapy.

  3. Large-angle coherent/Compton scattering method for measurement in vitro of trabecular bone mineral concentration

    International Nuclear Information System (INIS)

    Gigante, G.E.; Sciuti, S.

    1985-01-01

    In this paper, experiments and related theoretical deductions on coherent/Compton scattering of 59.5-keV Am241 gamma line by bonelike materials are described. In particular, the authors demonstrate that a photon scattering mineralometer (PSM) can attain the best working conditions when it operates in a backscattering geometry mode. In fact, the large scattering angle they chose, theta = 135 degrees, allowed them to assemble a very compact source-detector device. Further, the relative sensitivity at 135 degrees turns out to be congruent to 1.7 and congruent to 6 times bigger than at 90 degrees and 45 degrees, respectively. The performances of the theta = 135 degrees PSM were experimentally investigated; i.e., in a measuring time of 10(3) s, a congruent to 5% statistical precision for bonelike materials, such as K 2 HPO 4 -water solutions, was obtained. The large-angle PSM device seems to be very promising for trabecular bone mineral density measurements in vivo in peripheral anatomic sites

  4. Histomorphometric Parameters of the Growth Plate and Trabecular Bone in Wild-Type and Trefoil Factor Family 3 (Tff3)-Deficient Mice Analyzed by Free and Open-Source Image Processing Software.

    Science.gov (United States)

    Bijelić, Nikola; Belovari, Tatjana; Stolnik, Dunja; Lovrić, Ivana; Baus Lončar, Mirela

    2017-08-01

    Trefoil factor family 3 (Tff3) peptide is present during intrauterine endochondral ossification in mice, and its deficiency affects cancellous bone quality in secondary ossification centers of mouse tibiae. The aim of this study was to quantitatively analyze parameters describing the growth plate and primary ossification centers in tibiae of 1-month-old wild-type and Tff3 knock-out mice (n=5 per genotype) by using free and open-source software. Digital photographs of the growth plates and trabecular bone were processed by open-source computer programs GIMP and FIJI. Histomorphometric parameters were calculated using measurements made with FIJI. Tff3 knock-out mice had significantly smaller trabecular number and significantly larger trabecular separation. Trabecular bone volume, trabecular bone surface, and trabecular thickness showed no significant difference between the two groups. Although such histomorphological differences were found in the cancellous bone structure, no significant differences were found in the epiphyseal plate histomorphology. Tff3 peptide probably has an effect on the formation and quality of the cancellous bone in the primary ossification centers, but not through disrupting the epiphyseal plate morphology. This work emphasizes the benefits of using free and open-source programs for morphological studies in life sciences.

  5. Bone ingrowth potential of electron beam and selective laser melting produced trabecular-like implant surfaces with and without a biomimetic coating.

    Science.gov (United States)

    Biemond, J E; Hannink, G; Verdonschot, N; Buma, P

    2013-03-01

    The bone ingrowth potential of trabecular-like implant surfaces produced by either selective laser melting (SLM) or electron beam melting (EBM), with or without a biomimetic calciumphosphate coating, was examined in goats. For histological analysis and histomorphometry of bone ingrowth depth and bone implant contact specimens were implanted in the femoral condyle of goats. For mechanical push out tests to analyse mechanical implant fixation specimens were implanted in the iliac crest. The follow up periods were 4 (7 goats) and 15 weeks (7 goats). Both the SLM and EBM produced trabecular-like structures showed a variable bone ingrowth after 4 weeks. After 15 weeks good bone ingrowth was found in both implant types. Irrespective to the follow up period, and the presence of a coating, no histological differences in tissue reaction around SLM and EBM produced specimens was found. Histological no coating was detected at 4 and 15 weeks follow up. At both follow up periods the mechanical push out strength at the bone implant interface was significantly lower for the coated SLM specimens compared to the uncoated SLM specimens. The expected better ingrowth characteristics and mechanical fixation strength induced by the coating were not found. The lower mechanical strength of the coated specimens produced by SLM is a remarkable result, which might be influenced by the gross morphology of the specimens or the coating characteristics, indicating that further research is necessary.

  6. Electron absorbed fractions of energy and S-values in an adult human skeleton based on {mu}CT images of trabecular bone

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, R; Cassola, V F; Khoury, H J; De O Lira, C A B [Department of Nuclear Energy, Federal University of Pernambuco, Avenida Professor Luiz Freire, 1000, CEP 50740-540, Recife (Brazil); Richardson, R B [Radiation Protection Research and Instrumentation Branch, Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, ON, K0J 1J0 (Canada); Vieira, J W [Federal Institute of Education, Science and Technology of Pernambuco, Recife (Brazil); Brown, K Robson, E-mail: rkramer@uol.com.br [Imaging Laboratory, Department of Archaeology and Anthropology, University of Bristol, Bristol (United Kingdom)

    2011-03-21

    When the human body is exposed to ionizing radiation, among the soft tissues at risk are the active marrow (AM) and the bone endosteum (BE) located in tiny, irregular cavities of trabecular bone. Determination of absorbed fractions (AFs) of energy or absorbed dose in the AM and the BE represent one of the major challenges of dosimetry. Recently, at the Department of Nuclear Energy at the Federal University of Pernambuco, a skeletal dosimetry method based on {mu}CT images of trabecular bone introduced into the spongiosa voxels of human phantoms has been developed and applied mainly to external exposure to photons. This study uses the same method to calculate AFs of energy and S-values (absorbed dose per unit activity) for electron-emitting radionuclides known to concentrate in skeletal tissues. The modelling of the skeletal tissue regions follows ICRP110, which defines the BE as a 50 {mu}m thick sub-region of marrow next to the bone surfaces. The paper presents mono-energetic AFs for the AM and the BE for eight different skeletal regions for electron source energies between 1 keV and 10 MeV. The S-values are given for the beta emitters {sup 14}C, {sup 59}Fe, {sup 131}I, {sup 89}Sr, {sup 32}P and {sup 90}Y. Comparisons with results from other investigations showed good agreement provided that differences between methodologies and trabecular bone volume fractions were properly taken into account. Additionally, a comparison was made between specific AFs of energy in the BE calculated for the actual 50 {mu}m endosteum and the previously recommended 10 {mu}m endosteum. The increase in endosteum thickness leads to a decrease of the endosteum absorbed dose by up to 3.7 fold when bone is the source region, while absorbed dose increases by {approx}20% when the beta emitters are in marrow.

  7. Is trabecular bone permeability governed by molecular ordering-induced fluid viscosity gain? Arguments from re-evaluation of experimental data in the framework of homogenization theory.

    Science.gov (United States)

    Abdalrahman, T; Scheiner, S; Hellmich, C

    2015-01-21

    It is generally agreed on that trabecular bone permeability, a physiologically important quantity, is governed by the material׳s (vascular or intertrabecular) porosity as well as by the viscosity of the pore-filling fluids. Still, there is less agreement on how these two key factors govern bone permeability. In order to shed more light onto this somewhat open issue, we here develop a random homogenization scheme for upscaling Poiseuille flow in the vascular porosity, up to Darcy-type permeability of the overall porous medium "trabecular bone". The underlying representative volume element of the macroscopic bone material contains two types of phases: a spherical, impermeable extracellular bone matrix phase interacts with interpenetrating cylindrical pore channel phases that are oriented in all different space directions. This type of interaction is modeled by means of a self-consistent homogenization scheme. While the permeability of the bone matrix equals to zero, the permeability of the pore phase is found through expressing the classical Hagen-Poiseuille law for laminar flow in the format of a "micro-Darcy law". The upscaling scheme contains pore size and porosity as geometrical input variables; however, they can be related to each other, based on well-known relations between porosity and specific bone surface. As two key results, validated through comprehensive experimental data, it appears (i) that the famous Kozeny-Carman constant (which relates bone permeability to the cube of the porosity, the square of the specific surface, as well as to the bone fluid viscosity) needs to be replaced by an again porosity-dependent rational function, and (ii) that the overall bone permeability is strongly affected by the pore fluid viscosity, which, in case of polarized fluids, is strongly increased due to the presence of electrically charged pore walls. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Fragility Fracture Incidence in Chronic Obstructive Pulmonary Disease (COPD) Patients Associates With Nanoporosity, Mineral/Matrix Ratio, and Pyridinoline Content at Actively Bone-Forming Trabecular Surfaces.

    Science.gov (United States)

    Paschalis, Eleftherios P; Gamsjaeger, Sonja; Dempster, David; Jorgetti, Vanda; Borba, Victoria; Boguszewski, Cesar L; Klaushofer, Klaus; Moreira, Carolina A

    2017-01-01

    Chronic obstructive pulmonary disease (COPD) is associated with low areal bone mineral density (aBMD) by dual-energy X-ray absorptiometry (DXA) and altered microstructure by bone histomorphometry and micro-computed tomography. Nevertheless, not all COPD patients sustain fragility fractures. In the present study, we used Raman microspectroscopic analysis to determine bone compositional properties at actively forming trabecular surfaces (based on double fluorescent labels) in iliac crest biopsies from 19 postmenopausal COPD patients (aged 62.1 ± 7.3 years). Additionally, we analyzed trabecular geometrical centers, representing tissue much older than the forming surfaces. Eight of the patients had sustained fragility fractures, and 13 had received treatment with inhaled glucocorticoids. None of the patients had taken oral glucocorticoids. The monitored parameters were mineral/matrix ratio (MM), nanoporosity, and relative glycosaminoglycan (GAG), lipid, and pyridinoline contents (PYD). There were no significant differences between the glucocorticoid-treated patients and those who did not receive any. On the other hand, COPD patients sustaining fragility fractures had significantly lower nanoporosity and higher MM and PYD values compared with COPD patients without fragility fractures. To the best of our knowledge, this is the first study to discriminate between fracture and non-fracture COPD patients based on differences in the material properties of bone matrix. Given that these bone material compositional differences are evident close to the cement line (a major bone interface), they may contribute to the inferior bone toughness and coupled with the lower lumbar spine bone mineral density values result in the fragility fractures prevalent in these patients. © 2016 American Society for Bone and Mineral Research. © 2016 American Society for Bone and Mineral Research.

  9. High bone mineral apparent density in children with X-linked hypophosphatemia

    DEFF Research Database (Denmark)

    Beck-Nielsen, Signe; Brixen, K; Gram, J

    2013-01-01

    of the spine compared to femoral neck. INTRODUCTION: BMAD obtained by dual-energy X-ray absorptiometry scans in children with XLH was evaluated, as they are unlikely to have the extra-skeletal ossifications contributing to the elevated bone mineral density of the spine in adult patients. METHODS: A total of 15......Bone mineral apparent density (BMAD) in children with X-linked hypophosphatemia (XLH) was evaluated, as they are unlikely to have extra-skeletal ossifications contributing to the elevated bone mineral density of the spine in adult patients. Children with XLH also had significantly higher BMAD...

  10. Role of disc area and trabecular bone density on lumbar spinal column fracture risk curves under vertical impact.

    Science.gov (United States)

    Yoganandan, Narayan; Moore, Jason; Pintar, Frank A; Banerjee, Anjishnu; DeVogel, Nicholas; Zhang, JiangYue

    2018-04-27

    While studies have been conducted using human cadaver lumbar spines to understand injury biomechanics in terms of stability/energy to fracture, and physiological responses under pure-moment/follower loads, data are sparse for inferior-to-superior impacts. Injuries occur under this mode from underbody blasts. determine role of age, disc area, and trabecular bone density on tolerances/risk curves under vertical loading from a controlled group of specimens. T12-S1 columns were obtained, pretest X-rays and CTs taken, load cells attached to both ends, impacts applied at S1-end using custom vertical accelerator device, and posttest X-ray, CT, and dissections done. BMD of L2-L4 vertebrae were obtained from QCT. Survival analysis-based Human Injury Probability Curves (HIPCs) were derived using proximal and distal forces. Age, area, and BMD were covariates. Forces were considered uncensored, representing the load carrying capacity. The Akaike Information Criterion was used to determine optimal distributions. The mean forces, ±95% confidence intervals, and Normalized Confidence Interval Size (NCIS) were computed. The Lognormal distribution was the optimal function for both forces. Age, area, and BMD were not significant (p > 0.05) covariates for distal forces, while only BMD was significant for proximal forces. The NCIS was the lowest for force-BMD covariate HIPC. The HIPCs for both genders at 35 and 45 years were based on population BMDs. These HIPCs serve as human tolerance criteria for automotive, military, and other applications. In this controlled group of samples, BMD is a better predictor-covariate that characterizes lumbar column injury under inferior-to-superior impacts. Published by Elsevier Ltd.

  11. Trabecular microstructure and surface changes in the greater tuberosity in rotator cuff tears

    International Nuclear Information System (INIS)

    Jiang, Yebin; Zhao, Jenny; Ouyang, Xiaolong; Genant, Harry K.; Holsbeeck, Marnix T. van; Flynn, Michael J.

    2002-01-01

    Abstract Objective. When planning surgery in patients with rotator cuff tear, strength of bone at the tendon insertion and trabecular bone structure in the greater tuberosity are usually taken into consideration. We investigated radiographic changes in bone structure of the greater tuberosity in rotator cuff tears.Design. Twenty-two human cadaveric shoulders from subjects ranging from 55 to 75 years of age were obtained. The integrity of the rotator cuff was examined by sonography to determine if it is intact without any tear, or torn partially or completely. The humeral head was sectioned in 3 mm thick coronal slab sections and microradiographed. After digitization of the microradiographs and imaging processing with in-house semi-automated image processing software tools developed using software interfaces on a Sun workstation, the trabecular histomorphometrical structural parameters and connectivity in the greater tuberosity were quantified. The degenerative changes on the surface of the greater tuberosity were interpreted blindly by 2 independent readers.Results. Among the 22 shoulder specimens, the rotator cuff was found intact in 10 shoulders, partially in 7 and fully torn in 5. Statistically significant loss in apparent trabecular bone volume fraction, number of trabecular nodes, and number of trabecular branches, and a statistically significant increase in apparent trabecular separation and number of trabecular free ends were found in the greater tuberosity of the shoulders with tears. The loss was greater in association with full tear than in partial tear. Thickening of the cortical margin of the enthesis, irregularity of its surface, and calcification beyond the tidemark were observed in 2 (20%) shoulders with intact rotator cuff, in 6 (86%) shoulders with partial tear, and in 5 (100%) shoulders with full tear.Conclusions. Rotator cuff tears are associated with degenerative changes on the bone surface and with disuse osteopenia of the greater tuberosity

  12. 3D porous architecture of stacks of β-TCP granules compared with that of trabecular bone: a microCT, vector analysis and compression study

    Directory of Open Access Journals (Sweden)

    Daniel eCHAPPARD

    2015-10-01

    Full Text Available The 3D arrangement of porous granular biomaterials usable to fill bone defects has received little study. Granular biomaterials occupy 3D space when packed together in a manner that creates a porosity suitable for the invasion of vascular and bone cells. Granules of β-TCP were prepared with either 12.5 or 25g of β-TCP powder in the same volume of slurry. When the granules were placed in a test tube, this produced 3D stacks with a high (HP or low porosity (LP, respectively. Stacks of granules mimic the filling of a bone defect by a surgeon. The aim of this study was to compare the porosity of stacks of β-TCP granules with that of cores of trabecular bone. Biomechanical compression tests were done on the granules stacks. Bone cylinders were prepared from calf tibia plateau, constituted high density (HD blocks. Low density (LD blocks were harvested from aged cadaver tibias. Microcomputed tomography was used on the β-TCP granule stacks and the trabecular bone cores to determine porosity and specific surface. A vector projection algorithm was used to image porosity employing a frontal plane image which was constructed line by line from all images of a microCT stack. Stacks of HP granules had porosity (75.3 ± 0.4% and fractal lacunarity (0.043 ± 0.007 intermediate between that of HD (resp. 69.1 ± 6.4%, p<0.05 and 0.087 ± 0.045, p<0.05 and LD bones (resp. 88.8 ± 1.57% and 0.037 ± 0.014 but exhibited a higher surface density (5.56 ± 0.11 mm2/mm3 vs. 2.06 ± 0.26 for LD, p<0.05. LP granular arrangements created large pores coexisting with dense areas of material. Frontal plane analysis evidenced a more regular arrangement of β-TCP granules than bone trabeculae. Stacks of HP granules represent a scaffold that resembles trabecular bone in its porous microarchitecture.

  13. Black bear parathyroid hormone has greater anabolic effects on trabecular bone in dystrophin-deficient mice than in wild type mice.

    Science.gov (United States)

    Gray, Sarah K; McGee-Lawrence, Meghan E; Sanders, Jennifer L; Condon, Keith W; Tsai, Chung-Jui; Donahue, Seth W

    2012-09-01

    Duchenne muscular dystrophy (DMD) is an X-linked neuromuscular disease that has deleterious consequences in muscle and bone, leading to decreased mobility, progressive osteoporosis, and premature death. Patients with DMD experience a higher-than-average fracture rate, particularly in the proximal and distal femur and proximal tibia. The dystrophin-deficient mdx mouse is a model of DMD that demonstrates muscle degeneration and fibrosis and osteoporosis. Parathyroid hormone, an effective anabolic agent for post-menopausal and glucocorticoid-induced osteoporosis, has not been explored for DMD. Black bear parathyroid hormone (bbPTH) has been implicated in the maintenance of bone properties during extended periods of disuse (hibernation). We cloned bbPTH and found 9 amino acid residue differences from human PTH. Apoptosis was mitigated and cAMP was activated by bbPTH in osteoblast cultures. We administered 28nmol/kg of bbPTH 1-84 to 4-week old male mdx and wild type mice via daily (5×/week) subcutaneous injection for 6 weeks. Vehicle-treated mdx mice had 44% lower trabecular bone volume fraction than wild type mice. No changes were found in femoral cortical bone geometry or mechanical properties with bbPTH treatment in wild type mice, and only medio-lateral moment of inertia changed with bbPTH treatment in mdx femurs. However, μCT analyses of the trabecular regions of the distal femur and proximal tibia showed marked increases in bone volume fraction with bbPTH treatment, with a greater anabolic response (7-fold increase) in mdx mice than wild type mice (2-fold increase). Trabecular number increased in mdx long bone, but not wild type bone. Additionally, greater osteoblast area and decreased osteoclast area were observed with bbPTH treatment in mdx mice. The heightened response to PTH in mdx bone compared to wild type suggests a link between dystrophin deficiency, altered calcium signaling, and bone. These findings support further investigation of PTH as an anabolic

  14. Combined Effects of Spaceflight and Age in Astronauts as Assessed by Areal Bone Mineral Density [BMD] and Trabecular Bone Score

    Science.gov (United States)

    Sibonga, Jean D.; Spector, Elizabeth R.; Ploutz-Snyder, R.; Evans, H. J.; King, L.; Watts, N. B.; Hans, D.; Smith, S. A.

    2013-01-01

    Spaceflight is a potential risk factor for secondary osteoporosis in astronauts. Although lumbar spine (LS) BMD declines rapidly, more than expected for age, there have been no fragility fractures in astronauts that can clearly be attributed to spaceflight. Recently, astronauts have been returning from 6-month spaceflights with absolute BMD still above young adult mean BMD. In spite of these BMD measurements, we project that the rapid loss in bone mass over long-duration spaceflight affects the bone microarchitecture of the LS which might predispose astronauts to premature vertebral fractures. Thus, we evaluated TBS, a novel texture index correlated with vertebral bone microarchitecture, as a means of monitoring changes to bone microarchitecture in astronauts as they age. We previously reported that TBS detects an effect of spaceflight (6-month duration), independent of BMD, in 51 astronauts (47+/-4 y) (Smith et al, J Clin Densitometry 2014). Hence, TBS was evaluated in serial DXA scans (Hologic Discovery W) conducted triennially in all active and retired astronauts and more frequently (before spaceflight, after spaceflight and until recovery) in the subset of astronauts flying 4-6- month missions. We used non-linear models to describe trends in observations (BMD or TBS) plotted as a function of astronaut age. We fitted 1175 observations of 311 astronauts, pre-flight and then postflight starting 3 years after landing or after astronaut's BMD for LS was restored to within 2% of preflight BMD. Observations were then grouped and defined as follows: 1) LD: after exposure to at least one long-duration spaceflight > 100 days and 2) SD: before LD and after exposure to at least one short-duration spaceflight < 30 days. Data from males and females were analyzed separately. Models of SD observations revealed that TBS and BMD had similar curvilinear declines with age for both male and female astronauts. However, models of LD observations showed TBS declining with age while

  15. Outcome of revision total knee arthroplasty with the use of trabecular metal cone for reconstruction of severe bone loss at the proximal tibia

    DEFF Research Database (Denmark)

    Jensen, Claus L; Olsen, Nikolaj Winther; Schrøder, Henrik M

    2014-01-01

    technology (TMT) cones for the reconstruction of tibial bone loss at the time of rTKA. METHODS: Thirty-six patients had rTKA with the use of a TMT Cone. Bone loss was classified according to the AORI classification and 25% of the patients suffered from T3 AORI defects and 75% of the patients from T2 AORI...... defects. Implants used were from the NexGen series. At follow-up, radiographs were evaluated according to the Knee Society Roentgenographic Scoring System. Knee and function score was calculated using the Knee Society Clinical Rating System. Average follow-up time was 47 months (range 3-84 months......BACKGROUND: The relative effectiveness of different methods for reconstructing large bone loss at the proximal tibia in revision total knee arthroplasty (rTKA) has not been established. The aim of this study was to evaluate the clinical and radiological outcome after the use of trabecular metal...

  16. Calcium and phosphorus concentrations and the calcium/phosphorus ratio in trabecular bone from the femoral neck of healthy humans as determined by neutron activation analysis

    International Nuclear Information System (INIS)

    Zaichick, Vladimir; Tzaphlidou, Margaret

    2003-01-01

    The Ca and P concentrations as well as the Ca/P ratio were estimated in intact trabecular bone samples from the femoral neck of healthy humans, 34 women and 44 men, aged from 15 to 55 years, using instrumental neutron activation analysis. The mean values (M±SD) for the investigated parameters (on a dry-weight basis) were: 12.1±3.0%, 5.94±1.71%, 2.07±0.25 and 10.9±2.5%, 5.30±1.23%, 2.07±0.22 for females and males, respectively. A statistically significant (p≤0.05) decrease of Ca concentration with age was found only for males while the P concentration and the Ca/P ratio were not affected by age. No statistically significant sex-related differences were observed in any of the parameters. The mean values for Ca, P and the Ca/P ratio lay close to the median of the very wide range of published data. The individual variation for the Ca/P ratio in trabecular bone from the healthy human femoral neck was lower than those for Ca and P separately. This suggests that the specificity of the Ca/P ratio is better than that of Ca and P concentrations and may be more reliable for the diagnosis of bone disorders

  17. The role of apparent diffusion coefficient in the differentiation between benign and malignant bone tumors

    International Nuclear Information System (INIS)

    Liu Jicun; Cui Jianling; Li Shiling; Guo Zhiping; Ma Xiaohui

    2009-01-01

    Objective: To explore the role of apparent diffusion coefficient (ADC) value of diffusion-weighted imaging (DWI) in the differentiation between benign and malignant bone tumors. Methods: Echo planar imaging DWI was performed in 18 patients with benign tumor or tumorous lesion and 26 patients with malignant tumor of bone. Three b-values (0, 500 and 1000 s/mm 2 ) were applied. The lowest, highest, and whole ADC values were measured for each lesion, respectively. Results: The lowest ADC values of benign bone tumor [mean (1.28 ± 0.49)x10 -3 mm 2 /s] were significantly higher than that of malignant tumor [ mean (0.92 ± 0.35) x10 -3 mm 2 /s,t =2.839,P -3 mm 2 /s] were significantly higher than that of malignant tumor [ mean (1.21 ± 0.36)x10 -3 mm 2 /s, t =3.092, P -3 mm 2 /s] and malignant bone tumor [ mean (1.71 ± 0.65)x10 -3 mm 2 /s, t = 1.669, P > 0.05]. Excluding cases of bone cyst and aneurismal bone cyst, the lowest, highest, and whole ADC values of benign bone tumor waw (1.11 ± 0.31)x10 -3 mm 2 /s, (1.88 ± 0.49)x10 -3 mm 2 /s, and (1.45 ± 0.35)x10 -3 mm 2 /s, respectively. There was no significant difference for the lowest, highest, or whole ADC values between benign and malignant bone tumor (t =1.728, 0.964, and 2.012, respectively, P> 0.05). Conclusion: ADC value is useless for the differentiation between benign and malignant bone tumors. (authors)

  18. TRABECULAR BONE SCORE – A NON-INVASIVE ANALYTICAL METHOD TO EVALUATE BONE QUALITY BASED ON ROUTINE DUAL-ENERGY ABSORPTIOMETRY. PERSPECTIVES OF ITS USE IN CLINICAL PRACTICE

    Directory of Open Access Journals (Sweden)

    T. T. Tsoriev

    2016-01-01

    Full Text Available Two-dimensional dual-energy X-ray absorptiometry (DXA, osteodensitometry is currently considered as the gold standard for diagnosis of osteoporosis. However, despite good operational characteristics, this type of investigation cannot help to assess bone microarchitecture and the degree of its derangement in osteoporosis. Therefore, trabecular bone score (TBS has been developed as a  non-invasive method of indirect description of bone microarchitecture based on data derived from a  standard DXA of the lumbar spine. Not being a direct mapping of the physical measurements of trabecular microarchitecture, TBS nevertheless shows a positive correlation with quantitative values obtained from micro-computed tomography and high resolution peripheral quantitative computed tomography, i.e. with the bone volume fraction, junction density, trabecular numbers and their disintegration. There is also an association between the ability of the bone tissue to resist stress in experimental studies ex vivo and TBS measurement. Due to TBS, there is a possibility to detect bone microarchitecture impairment even in individuals with normal bone mineral density (BMD, i.e. higher TBS values correlate with improved bone microstructure, whereas a  reduced TBS shows its deterioration. Limitation of TBS use are primarily related to the DXA image quality: image faults caused either by technical reasons or by too low or too high body mass index can lead to an overestimation/underestimation of the index. Assessment of the lumbar TBS has been repeatedly performed in cross-sectional and prospective studies in representative patient samples (mainly postmenopausal women and significant numbers of healthy subjects, and proved to be a predictor (independent of BMD of fracture risk. An evaluation of the possibility to use TBS for early diagnosis of secondary osteoporosis (related to various endocrine disorders  would be of great interest, as BMD, as known from clinical

  19. Variation in primary and culture-expanded cells derived from connective tissue progenitors in human bone marrow space, bone trabecular surface and adipose tissue.

    Science.gov (United States)

    Qadan, Maha A; Piuzzi, Nicolas S; Boehm, Cynthia; Bova, Wesley; Moos, Malcolm; Midura, Ronald J; Hascall, Vincent C; Malcuit, Christopher; Muschler, George F

    2018-03-01

    Connective tissue progenitors (CTPs) embody the heterogeneous stem and progenitor cell populations present in native tissue. CTPs are essential to the formation and remodeling of connective tissue and represent key targets for tissue-engineering and cell-based therapies. To better understand and characterize CTPs, we aimed to compare the (i) concentration and prevalence, (ii) early in vitro biological behavior and (iii) expression of surface-markers and transcription factors among cells derived from marrow space (MS), trabecular surface (TS), and adipose tissues (AT). Cancellous-bone and subcutaneous-adipose tissues were collected from 8 patients. Cells were isolated and cultured. Colony formation was assayed using Colonyze software based on ASTM standards. Cell concentration ([Cell]), CTP concentration ([CTP]) and CTP prevalence (P CTP ) were determined. Attributes of culture-expanded cells were compared based on (i) effective proliferation rate and (ii) expression of surface-markers CD73, CD90, CD105, SSEA-4, SSEA-3, SSEA-1/CD15, Cripto-1, E-Cadherin/CD324, Ep-CAM/CD326, CD146, hyaluronan and transcription factors Oct3/4, Sox-2 and Nanog using flow cytometry. Mean [Cell], [CTP] and P CTP were significantly different between MS and TS samples (P = 0.03, P = 0.008 and P= 0.0003), respectively. AT-derived cells generated the highest mean total cell yield at day 6 of culture-4-fold greater than TS and more than 40-fold greater than MS per million cells plated. TS colonies grew with higher mean density than MS colonies (290 ± 11 versus 150 ± 11 cell per mm 2 ; P = 0.0002). Expression of classical-mesenchymal stromal cell (MSC) markers was consistently recorded (>95%) from all tissue sources, whereas all the other markers were highly variable. The prevalence and biological potential of CTPs are different between patients and tissue sources and lack variation in classical MSC markers. Other markers are more likely to discriminate differences

  20. Trabecular bone score as an assessment tool to identify the risk of osteoporosis in axial spondyloarthritis: a case-control study.

    Science.gov (United States)

    Kang, Kwi Young; Goo, Hye Yeon; Park, Sung-Hwan; Hong, Yeon Sik

    2018-03-01

    To compare the trabecular bone score (TBS) between patients with axial spondyloarthritis (axSpA) and matched normal controls and identify risk factors associated with a low TBS. TBS and BMD were assessed in the two groups (axSpA and control) using DXA. Osteoporosis risk factors and inflammatory markers were also assessed. Disease activity and radiographic progression in the sacroiliac joint and spine were evaluated in the axSpA group. Multivariate linear regression analysis was performed to identify risk factors associated with TBS. In the axSpA group, 248 subjects were enrolled; an equal number of age- and sex-matched subjects comprised the control group. The mean TBS was 1.43 (0.08) and 1.38 (0.12) in the control and axSpA groups, respectively (P tool to identify the risk of osteoporosis in patients with axSpA.

  1. Joint unloading implant modifies subchondral bone trabecular structure in medial knee osteoarthritis: 2-year outcomes of a pilot study using fractal signature analysis

    Directory of Open Access Journals (Sweden)

    Miller LE

    2015-01-01

    Full Text Available Larry E Miller,1,2 Miki Sode,3 Thomas Fuerst,3 Jon E Block2 1Miller Scientific Consulting, Inc., Asheville, NC, USA; 2The Jon Block Group, San Francisco, CA, USA; 3Bioclinica, Newark, CA, USA Background: Knee osteoarthritis (OA is largely attributable to chronic excessive and aberrant joint loading. The purpose of this pilot study was to quantify radiographic changes in subchondral bone after treatment with a minimally invasive joint unloading implant (KineSpring® Knee Implant System.Methods: Nine patients with unilateral medial knee OA resistant to nonsurgical therapy were treated with the KineSpring System and followed for 2 years. Main outcomes included Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC pain, function, and stiffness subscores and independent core laboratory determinations of joint space width and fractal signature of the tibial cortex.Results: WOMAC scores, on average, improved by 92% for pain, 91% for function, and 79% for stiffness over the 2-year follow-up period. Joint space width in the medial compartment of the treated knee significantly increased from 0.9 mm at baseline to 3.1 mm at 2 years; joint space width in the medial compartment of the untreated knee was unchanged. Fractal signatures of the vertically oriented trabeculae in the medial compartment decreased by 2.8% in the treated knee and increased by 2.1% in the untreated knee over 2 years. No statistically significant fractal signature changes were observed in the horizontally oriented trabeculae in the medial compartment or in the horizontal or vertical trabeculae of the lateral compartment in the treated knee.Conclusion: Preliminary evidence suggests that the KineSpring System may modify knee OA disease progression by increasing joint space width and improving subchondral bone trabecular integrity, thereby reducing pain and improving joint function. Keywords: disease modification, KineSpring, joint space, pain, trabecular

  2. Effects of low calcium plus high aluminum diet on magnesium and calcium contents in spinal cord and trabecular bone of rats

    Energy Technology Data Exchange (ETDEWEB)

    Yasui, Masayuki; Ota, Kiichiro [Wakayama Medical Coll. (Japan); Sasajima, Kazuhisa

    1998-01-01

    Current epidemiological surveys in the Western Pacific area and Kii Peninsula have suggested that low calcium (Ca), magnesium (Mg), and high aluminum (Al) and manganese (Mn) in river, soil and drinking water may be implicated in the pathogenetic process of amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia (PD). The condition of unbalanced minerals was experimentally duplicated in this study using rats. Male Wistar rats, weighing 200 g, were maintained for 60 days on the following diets: (A) standard diet, (B) low Ca diet, (C) low Ca diet with high Al. Magnesium concentration was determined in spinal cord and trabecular bone using inductively coupled plasma emission spectrometry (ICP) and the calcium concentration was determined using neutron activation method. In the group maintained on low Ca high Al diet, magnesium content of the spinal cord was lower than the group fed standard diet. Also, magnesium content of lumbar bone showed lower values in the unbalanced diet group fed low Ca high Al diet than those in the standard diet and low Ca diet groups. Calcium content of spinal cord was highest in rats maintained on low Ca high Al diet. Calcium content in lumbar bone of rats significantly decreased in rats maintained on the low Ca diet (group B and C) compared to rats given a standard diet (group A). Our data indicate that low Ca and high Al dietary intake influence Mg concentration in bone and central nervous system (CNS) tissues and that low Ca and high Al diet diminish Mg in bone and CNS tissues, thereby inducing loss of calcification in bone and degeneration of CNS tissues due to disturbance of the normal biological effects of Mg. (author)

  3. Compromised trabecular microarchitecture and lower finite element estimates of radius and tibia bone strength in adults with turner syndrome

    DEFF Research Database (Denmark)

    Hansen, Stinus; Brixen, Kim; Gravholt, Claus H

    2012-01-01

    Although bone mass appear ample for bone size in Turner syndrome (TS), epidemiological studies have reported an increased risk of fracture in TS. We used high-resolution peripheral quantitative computed tomography (HR-pQCT) to measure standard morphological parameters of bone geometry...

  4. In Vivo Over-expression of Circulating Dlk1/Pref-1 Protein Using Hydrodynamic-based Gene Transfer Leads to Lower Bone mass With Marked Effects on Trabecular Bone Micro-architecture

    DEFF Research Database (Denmark)

    Ding, Ming

    determined by PIXImus (LunarR) and micro-CT (ScancoR) respectively. We could only localize the plasmid in the liver and no complications were detected due to transgene expression. Serum levels of FA1 in Dlk1 injected mice (Dlk1+mice) was elevated by more than 15 folds compared to control saline injected mice...... and BMD was negatively correlated with the circulating levels of FA1. Micro-CT analysis revealed significantly decreased micro-architectural parameters of trabecular bone in the distal femur and proximal tibia of the Dlk1+mice compared to controls (see table). Naked DNA delivery by hydrodynamic injection...

  5. Development of a 3-D x-ray micro-tomography system and its application to trabecular bone/cement interface

    International Nuclear Information System (INIS)

    Chi, Yong Ki; Cho, Gyuseong

    2004-01-01

    In recent years, the interface analysis of micro-structure based objects is an important research in osteoporosis, vascular imaging since a 3-D X-ray micro-tomography system was developed. However, the micro-tomographic image shows the white-out appearance in case of imaging of similar density objects with low energy X-ray. Therefore these images must be analyzed about the interface between microstructure based objects for its application to biomechanical study. Many published studies suggested approximately assumed model of interface and predicted mechanical failure by means of Finite Element Method (FEM) but these FEM analysis has not used for modeling the real structure and interface between objects such as roughness, voids and pores of objects. We developed micro-tomography system and suggest the application of micro-tomographic image for predicting mechanical failure at the interface. The micro-tomography system consists of a 5 μm micro-focus X-ray tube, a CMOS-based image sensor and a rotating sample holder controlled by a precision motor. CMOS image sensor has 62x62 mm 2 sensing area and uses optical lenses system for increasing resolution. The sample which was manufactured by implanting cement in a pig hip bone was used and its fracture is considered to be an important cause of loosening of hip joint replacement in orthopedic implants. A Feldkamp's cone-beam reconstruction algorithm on the equispatial detector case was used for bone/cement 3D volume data and the analysis of a trabecular bone/cement interface containing white-out appearance was performed by using multiple criterion segmentation of region and volume. Finally, the segmented data can be used for fracture prediction of FEM by determining node of hexahedron meshing. In this paper, we present development of a 3-D cone beam micro-tomographic system with CMOS image sensor and its application to a complex structure of a trabecular bone and implanted cement for predicting the failure mechanism of

  6. Pregnant ewes exposed to multiple endocrine disrupting pollutants through sewage sludge-fertilized pasture show an anti-estrogenic effect in their trabecular bone

    International Nuclear Information System (INIS)

    Lind, P. Monica; Oberg, Denise; Larsson, Sune; Kyle, Carol E.; Orberg, Jan; Rhind, Stewart M.

    2010-01-01

    Pregnant ewes were maintained on pastures fertilized, twice yearly, with either sewage sludge (2.25 tonnes dry matter/ha; Treated; T) or inorganic fertilizer containing equivalent amounts of nitrogen (Control; C), to determine effects on maternal and fetal bone structures, density and mechanical properties of exposure to environmental concentrations of multiple endocrine disrupting compounds (EDCs) and heavy metal pollutants. The ewes were maintained on the respective pastures from the age of about 8 months until they were 4-6 years of age and they were slaughtered at 110 d gestation. Metaphyseal parts of adult ewe femurs exhibited a significantly reduced mean, total cross sectional area (CSA, - 4%; p 3 , - 8.0%; p 2 , - 11.1%; p < 0.05) in T compared with C animals. Femurs of T ewes were stronger than those of C ewes but this may reflect greater body weights. At the mid-diaphyseal part of the fetal bones, there was a reduction in endosteal circumference (- 6.7%, p < 0.05) and marrow cavity area (- 13.8%, p < 0.05) in the female T fetuses compared with female C fetuses. In the male fetuses the mid-diaphyseal part total bone mineral content was higher (+ 3.0%, p < 0.05) in T than in C animals. No treatment difference in biomechanical bending was detected in the fetuses. It is concluded that ewes grazing pasture fertilized with sewage sludge exhibited an anti-estrogenic effect on their trabecular bone in the form of reduced mineral content and density, despite increased body weight. It is suggested that human exposure to low levels of multiple EDCs may have implications for bone structure and human health.

  7. Role of apparent diffusion coefficients with diffusion-weighted magnetic resonance imaging in differentiating between benign and malignant bone tumors.

    Science.gov (United States)

    Wang, Tingting; Wu, Xiangru; Cui, Yanfen; Chu, Caiting; Ren, Gang; Li, Wenhua

    2014-11-29

    Benign and malignant bone tumors can present similar imaging features. This study aims to evaluate the significance of apparent diffusion coefficients (ADC) in differentiating between benign and malignant bone tumors. A total of 187 patients with 198 bone masses underwent diffusion-weighted (DW) magnetic resonance (MR) imaging. The ADC values in the solid components of the bone masses were assessed. Statistical differences between the mean ADC values in the different tumor types were determined by Student's t-test. Histological analysis showed that 84/198 (42.4%) of the bone masses were benign and 114/198 (57.6%) were malignant. There was a significant difference between the mean ADC values in the benign and malignant bone lesions (Pbenign and malignant bone tumors.

  8. Development and initial validation of a novel smoothed-particle hydrodynamics-based simulation model of trabecular bone penetration by metallic implants.

    Science.gov (United States)

    Kulper, Sloan A; Fang, Christian X; Ren, Xiaodan; Guo, Margaret; Sze, Kam Y; Leung, Frankie K L; Lu, William W

    2018-04-01

    A novel computational model of implant migration in trabecular bone was developed using smoothed-particle hydrodynamics (SPH), and an initial validation was performed via correlation with experimental data. Six fresh-frozen human cadaveric specimens measuring 10 × 10 × 20 mm were extracted from the proximal femurs of female donors (mean age of 82 years, range 75-90, BV/TV ratios between 17.88% and 30.49%). These specimens were then penetrated under axial loading to a depth of 10 mm with 5 mm diameter cylindrical indenters bearing either flat or sharp/conical tip designs similar to blunt and self-tapping cancellous screws, assigned in a random manner. SPH models were constructed based on microCT scans (17.33 µm) of the cadaveric specimens. Two initial specimens were used for calibration of material model parameters. The remaining four specimens were then simulated in silico using identical material model parameters. Peak forces varied between 92.0 and 365.0 N in the experiments, and 115.5-352.2 N in the SPH simulations. The concordance correlation coefficient between experimental and simulated pairs was 0.888, with a 95%CI of 0.8832-0.8926, a Pearson ρ (precision) value of 0.9396, and a bias correction factor Cb (accuracy) value of 0.945. Patterns of bone compaction were qualitatively similar; both experimental and simulated flat-tipped indenters produced dense regions of compacted material adjacent to the advancing face of the indenter, while sharp-tipped indenters deposited compacted material along their peripheries. Simulations based on SPH can produce accurate predictions of trabecular bone penetration that are useful for characterizing implant performance under high-strain loading conditions. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1114-1123, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  9. Simulation of 239Pu location in trabecular bone: a computerized model of adult endosteal bone remodeling and its interaction with injected 239Pu

    International Nuclear Information System (INIS)

    Kimmel, D.B.; Jee, W.S.S.

    1979-01-01

    A computer simulation of the relationship of bone microanatomic metabolic activity to the microscopic location of 239 Pu in bone has been attempted. The model incorporates the rate of bone turnover, cell location and density, bone resorptive activity (as it removes 239 Pu from bone), bone formation activity (as it buries 239 Pu in bone), recycling of 239 Pu, and liver translocation of 239 Pu to bone, such that the skeletal retention curve for 239 Pu injected in monomeric form into the young adult beagle is matched. The eventual aim of this work is to calculate the radiation dose to bone cells, knowing the relative location of 239 Pu deposited in bone and the cells that reside at bone surfaces as it changes throughout the lifespan of an animal. Early results indicate that osteosarcoma incidence may be proportional to the number of alpha hits which occur to osteoprogenitor cells and osteoblasts, the dividing cell population found near surfaces where bone turnover is in progress

  10. Dosimetric validation of synthetic trabecular bone generated by parametric Monte Carlo Method; Validação dosimétrica de trabéculas ósseas sintéticas geradas por método Monte Carlo paramétrico

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, F.G.; Andrade, A.F.G. de; Vieira, J.W., E-mail: baby.oliveira@hotmail.com.br, E-mail: arthurfelandrade@gmail.com, E-mail: jose.wilson59@uol.com.br [Instituto Federal de Pernambuco (IFPE), Recife, PE (Brazil); Oliveira, A.C.H. de, E-mail: oliveira_ach@yahoo.com [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil); Lima, F.R.A., E-mail: falima@cnen.gov.br [Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife-PE (Brazil)

    2017-07-01

    One of the greatest challenges of numerical dosimetry is to estimate the dose of ionizing radiation absorbed by the soft tissues that are located in bone trabecular. Due to the difficulty in obtaining micro-CT images of real bone samples (OR), the need for the generation of synthetic bone trabecular appeared. In this work, virtual synthetic trabecular samples (BU), generated by Monte Carlo methods parameterized by the Burr XII probability density function (FDP), and their OR equivalents were submitted to dosimetric evaluations in the adult male Computational Exposure Model (MCE) in orthostatic position (MSTA) coupled to the EGSnrc software with idealized photon-emitting sources and targeting the two most radiosensitive bone tissues: red bone marrow and the foramen-bone surface of trabecular bones, sternum, spine, femur, pelvis and skull regions. When comparing the dosimetric results of the two sample sets, it was found that the overall relative error presented was 4.34%. It is concluded that the synthetic trabecular generated by FDPs with the same characteristics as the Burr XII FDP can successfully replace the OR bones in similar bone dosimetry tests.

  11. Synchrotron radiation X-ray microtomography and histomorphometry for evaluation of chemotherapy effects in trabecular bone structure

    International Nuclear Information System (INIS)

    Alessio, R; Almeida, A P; Braz, D; Nogueira, L P; Colaço, M V; Barroso, R C; Andrade, C B V; Salata, C; De Almeida, C E; Ferreira-Machado, S C; Tromba, G

    2014-01-01

    Three-dimensional microtomography has the potential to examine complete bones of small laboratory animals with very high resolution in a non-invasive way. One of the side effects caused by some chemotherapy drugs is the induction of amenorrhea, temporary or not, in premenopausal women, with a consequent decrease in estrogen production, which can lead to bone changes. In the present work, the femur heads of rats treated with chemotherapy drugs were evaluated by 3D histomorphometry using synchrotron radiation microcomputed tomography. Control animals were also evaluated for comparison. The 3D tomographic images were obtained at the SYRMEP (SYnchrotron Radiation for MEdical Physics) beamline at the Elettra Synchrotron Laboratory in Trieste, Italy. Results showed significant differences in morphometric parameters measured from the 3D images of femur heads of rats in both analyzed groups.

  12. Synchrotron radiation X-ray microtomography and histomorphometry for evaluation of chemotherapy effects in trabecular bone structure

    Science.gov (United States)

    Alessio, R.; Nogueira, L. P.; Almeida, A. P.; Colaço, M. V.; Braz, D.; Andrade, C. B. V.; Salata, C.; Ferreira-Machado, S. C.; de Almeida, C. E.; Tromba, G.; Barroso, R. C.

    2014-04-01

    Three-dimensional microtomography has the potential to examine complete bones of small laboratory animals with very high resolution in a non-invasive way. One of the side effects caused by some chemotherapy drugs is the induction of amenorrhea, temporary or not, in premenopausal women, with a consequent decrease in estrogen production, which can lead to bone changes. In the present work, the femur heads of rats treated with chemotherapy drugs were evaluated by 3D histomorphometry using synchrotron radiation microcomputed tomography. Control animals were also evaluated for comparison. The 3D tomographic images were obtained at the SYRMEP (SYnchrotron Radiation for MEdical Physics) beamline at the Elettra Synchrotron Laboratory in Trieste, Italy. Results showed significant differences in morphometric parameters measured from the 3D images of femur heads of rats in both analyzed groups.

  13. Characterization of trabecular bone plate-rod microarchitecture using multirow detector CT and the tensor scale: Algorithms, validation, and applications to pilot human studies

    Science.gov (United States)

    Saha, Punam K.; Liu, Yinxiao; Chen, Cheng; Jin, Dakai; Letuchy, Elena M.; Xu, Ziyue; Amelon, Ryan E.; Burns, Trudy L.; Torner, James C.; Levy, Steven M.; Calarge, Chadi A.

    2015-01-01

    Purpose: Osteoporosis is a common bone disease associated with increased risk of low-trauma fractures leading to substantial morbidity, mortality, and financial costs. Clinically, osteoporosis is defined by low bone mineral density (BMD); however, increasing evidence suggests that trabecular bone (TB) microarchitectural quality is an important determinant of bone strength and fracture risk. A tensor scale based algorithm for in vivo characterization of TB plate-rod microarchitecture at the distal tibia using multirow detector CT (MD-CT) imaging is presented and its performance and applications are examined. Methods: The tensor scale characterizes individual TB on the continuum between a perfect plate and a perfect rod and computes their orientation using optimal ellipsoidal representation of local structures. The accuracy of the method was evaluated using computer-generated phantom images at a resolution and signal-to-noise ratio achievable in vivo. The robustness of the method was examined in terms of stability across a wide range of voxel sizes, repeat scan reproducibility, and correlation between TB measures derived by imaging human ankle specimens under ex vivo and in vivo conditions. Finally, the application of the method was evaluated in pilot human studies involving healthy young-adult volunteers (age: 19 to 21 yr; 51 females and 46 males) and patients treated with selective serotonin reuptake inhibitors (SSRIs) (age: 19 to 21 yr; six males and six females). Results: An error of (3.2% ± 2.0%) (mean ± SD), computed as deviation from known measures of TB plate-width, was observed for computer-generated phantoms. An intraclass correlation coefficient of 0.95 was observed for tensor scale TB measures in repeat MD-CT scans where the measures were averaged over a small volume of interest of 1.05 mm diameter with limited smoothing effects. The method was found to be highly stable at different voxel sizes with an error of (2.29% ± 1.56%) at an in vivo voxel size

  14. Using a method based on Potts Model to segment a micro-CT image stack of trabecular bones of femoral region

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Pedro H.A. de; Cabral, Manuela O.M., E-mail: andrade.pha@gmail.com [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Departamento de Engenharia Nuclear; Vieira, Jose W.; Correia, Filipe L. de B., E-mail: jose.wilson59@uol.com.br [Instituto Federal de Educacao, Ciencia e Tecnologia de Pernambuco (IFPE), Recife, PE (Brazil); Lima, Fernando R. De A., E-mail: falima@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (brazil)

    2015-07-01

    Exposure Computational Models are composed basically of an anthropomorphic phantom, a Monte Carlo (MC) code, and an algorithm simulator of the radioactive source. Tomographic phantoms are developed from medical images and must be pre-processed and segmented before being coupled to a MC code (which simulates the interaction of radiation with matter). This work presents a methodology used for treatment of micro-CT images stack of a femur, obtained from a 30 year old female skeleton provided by the Imaging Laboratory for Anthropology of the University of Bristol, UK. These images contain resolution of 60 micrometers and from these a block containing only 160 x 60 x 160 pixels of trabecular tissues and bone marrow was cut and saved as ⁎.sgi file (header + ⁎.raw file). The Grupo de Dosimetria Numerica (Recife-PE, Brazil) developed a software named Digital Image Processing (DIP), in which a method for segmentation based on a physical model for particle interaction known as Potts Model (or q-Ising) was implemented. This model analyzes the statistical dependence between sites in a network. In Potts Model, when the values of spin variables at neighboring sites are identical, it is assigned an 'energy of interaction' between them. Otherwise, it is said that the sites do not interact. Making an analogy between network sites and the pixels of a digital image and, moreover, between the spins variables and the intensity of the gray scale, it was possible to apply this model to obtain texture descriptors and segment the image. (author)

  15. Using a method based on Potts Model to segment a micro-CT image stack of trabecular bones of femoral region

    International Nuclear Information System (INIS)

    Andrade, Pedro H.A. de; Cabral, Manuela O.M.; Lima, Fernando R. De A.

    2015-01-01

    Exposure Computational Models are composed basically of an anthropomorphic phantom, a Monte Carlo (MC) code, and an algorithm simulator of the radioactive source. Tomographic phantoms are developed from medical images and must be pre-processed and segmented before being coupled to a MC code (which simulates the interaction of radiation with matter). This work presents a methodology used for treatment of micro-CT images stack of a femur, obtained from a 30 year old female skeleton provided by the Imaging Laboratory for Anthropology of the University of Bristol, UK. These images contain resolution of 60 micrometers and from these a block containing only 160 x 60 x 160 pixels of trabecular tissues and bone marrow was cut and saved as ⁎.sgi file (header + ⁎.raw file). The Grupo de Dosimetria Numerica (Recife-PE, Brazil) developed a software named Digital Image Processing (DIP), in which a method for segmentation based on a physical model for particle interaction known as Potts Model (or q-Ising) was implemented. This model analyzes the statistical dependence between sites in a network. In Potts Model, when the values of spin variables at neighboring sites are identical, it is assigned an 'energy of interaction' between them. Otherwise, it is said that the sites do not interact. Making an analogy between network sites and the pixels of a digital image and, moreover, between the spins variables and the intensity of the gray scale, it was possible to apply this model to obtain texture descriptors and segment the image. (author)

  16. Short-term precision assessment of trabecular bone score and bone mineral density using dual-energy X-ray absorptiometry with different scan modes: an in vivo study

    Energy Technology Data Exchange (ETDEWEB)

    Bandirali, Michele; Poloni, Alessandro; Messina, Carmelo; Petrini, Marcello [Universita degli Studi di Milano, Scuola di Specializzazione in Radiodiagnostica, Milano (Italy); Sconfienza, Luca Maria; Sardanelli, Francesco [Unita di Radiologia, IRCCS Policlinico San Donato, San Donato Milanese (Italy); Universita degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, San Donato Milanese (Italy); Papini, Giacomo Davide Edoardo; Di Leo, Giovanni [Unita di Radiologia, IRCCS Policlinico San Donato, San Donato Milanese (Italy); Ulivieri, Fabio Massimo [IRCCS Fondazione Ca' Granda Ospedale Maggiore Policlinico, Mineralometria Ossea Computerizzata e Ambulatorio Malattie Metabolismo Minerale e Osseo, Servizio di Medicina Nucleare, Milano (Italy)

    2015-07-15

    We estimated the in vivo reproducibility of trabecular bone score (TBS) from dual-energy X-ray absorptiometry (DXA) using different imaging modes to be compared to that of bone mineral density (BMD). We enrolled 30 patients for each imaging mode: fast-array, array, high definition. Each patient underwent two DXA examinations with in-between repositioning. BMD and TBS were obtained according to the International Society for Clinical Densitometry guidelines. The coefficient of variation (CoV) was calculated as the ratio between root mean square standard deviation and mean, percent least significant change (LSC) as 2.77 x CoV, reproducibility as the complement to 100 % LSC. Fast-array imaging mode resulted in 0.8 % CoV and 2.1 % LSC for BMD, 1.9 % and 5.3 % for TBS, respectively; array imaging mode resulted in 0.7 % and 2.0 % for BMD, 1.9 % and 5.2 %, for TBS; high-definition imaging mode resulted in 0.7 % and 2.0 %, for BMD; 2.0 % and 5.4 % for TBS, respectively. Reproducibility of TBS (95 %) was significantly lower than that of BMD (98 %) (p < 0.012). Difference in reproducibility among the imaging modes was not significant for either BMD or TBS (p = 0.942). While TBS reproducibility was significantly lower than that of BMD, differences among imaging modes were not significant for both TBS and BMD. (orig.)

  17. Particle migration and gap healing around trabecular metal implants

    DEFF Research Database (Denmark)

    Rahbek, O; Kold, S; Zippor, Berit

    2005-01-01

    Bone on-growth and peri-implant migration of polyethylene particles were studied in an experimental setting using trabecular metal and solid metal implants. Cylindrical implants of trabecular tantalum metal and solid titanium alloy implants with a glass bead blasted surface were inserted either i...

  18. Trabecular bone analysis in CT and X-ray images of the proximal femur for the assessment of local bone quality.

    Science.gov (United States)

    Fritscher, Karl; Grunerbl, Agnes; Hanni, Markus; Suhm, Norbert; Hengg, Clemens; Schubert, Rainer

    2009-10-01

    Currently, conventional X-ray and CT images as well as invasive methods performed during the surgical intervention are used to judge the local quality of a fractured proximal femur. However, these approaches are either dependent on the surgeon's experience or cannot assist diagnostic and planning tasks preoperatively. Therefore, in this work a method for the individual analysis of local bone quality in the proximal femur based on model-based analysis of CT- and X-ray images of femur specimen will be proposed. A combined representation of shape and spatial intensity distribution of an object and different statistical approaches for dimensionality reduction are used to create a statistical appearance model in order to assess the local bone quality in CT and X-ray images. The developed algorithms are tested and evaluated on 28 femur specimen. It will be shown that the tools and algorithms presented herein are highly adequate to automatically and objectively predict bone mineral density values as well as a biomechanical parameter of the bone that can be measured intraoperatively.

  19. Additively manufactured 3D porous Ti-6Al-4V constructs mimic trabecular bone structure and regulate osteoblast proliferation, differentiation and local factor production in a porosity and surface roughness dependent manner

    International Nuclear Information System (INIS)

    Cheng, Alice; Boyan, Barbara D; Humayun, Aiza; Cohen, David J; Schwartz, Zvi

    2014-01-01

    Additive manufacturing by laser sintering is able to produce high resolution metal constructs for orthopedic and dental implants. In this study, we used a human trabecular bone template to design and manufacture Ti-6Al-4V constructs with varying porosity via laser sintering. Characterization of constructs revealed interconnected porosities ranging from 15–70% with compressive moduli of 2579–3693 MPa. These constructs with macro porosity were further surface-treated to create a desirable multi-scale micro-/nano-roughness, which has been shown to enhance the osseointegration process. Osteoblasts (MG63 cells) exhibited high viability when grown on the constructs. Proliferation (DNA) and alkaline phosphatase specific activity, an early differentiation marker, decreased as porosity increased, while osteocalcin, a late differentiation marker, as well as osteoprotegerin, vascular endothelial growth factor and bone morphogenetic proteins 2 and 4 increased with increasing porosity. Three-dimensional (3D) constructs with the highest porosity and surface modification supported the greatest osteoblast differentiation and local factor production. These results indicate that additively manufactured 3D porous constructs mimicking human trabecular bone and produced with additional surface treatment can be customized for increased osteoblast response. Increased factors for osteoblast maturation and differentiation on high porosity constructs suggest the enhanced performance of these surfaces for increasing osseointegration in vivo. (paper)

  20. Additively manufactured 3D porous Ti-6Al-4V constructs mimic trabecular bone structure and regulate osteoblast proliferation, differentiation and local factor production in a porosity and surface roughness dependent manner.

    Science.gov (United States)

    Cheng, Alice; Humayun, Aiza; Cohen, David J; Boyan, Barbara D; Schwartz, Zvi

    2014-10-07

    Additive manufacturing by laser sintering is able to produce high resolution metal constructs for orthopedic and dental implants. In this study, we used a human trabecular bone template to design and manufacture Ti-6Al-4V constructs with varying porosity via laser sintering. Characterization of constructs revealed interconnected porosities ranging from 15-70% with compressive moduli of 2579-3693 MPa. These constructs with macro porosity were further surface-treated to create a desirable multi-scale micro-/nano-roughness, which has been shown to enhance the osseointegration process. Osteoblasts (MG63 cells) exhibited high viability when grown on the constructs. Proliferation (DNA) and alkaline phosphatase specific activity, an early differentiation marker, decreased as porosity increased, while osteocalcin, a late differentiation marker, as well as osteoprotegerin, vascular endothelial growth factor and bone morphogenetic proteins 2 and 4 increased with increasing porosity. Three-dimensional (3D) constructs with the highest porosity and surface modification supported the greatest osteoblast differentiation and local factor production. These results indicate that additively manufactured 3D porous constructs mimicking human trabecular bone and produced with additional surface treatment can be customized for increased osteoblast response. Increased factors for osteoblast maturation and differentiation on high porosity constructs suggest the enhanced performance of these surfaces for increasing osseointegration in vivo.

  1. Stereological measures of trabecular bone structure: comparison of 3D micro computed tomography with 2D histological sections in human proximal tibial bone biopsies

    DEFF Research Database (Denmark)

    Thomsen, Jesper Skovhus; Laib, A.; Koller, B.

    2005-01-01

    Stereology applied on histological sections is the 'gold standard' for obtaining quantitative information on cancellous bone structure. Recent advances in micro computed tomography (microCT) have made it possible to acquire three-dimensional (3D) data non-destructively. However, before the 3D...... methods can be used as a substitute for the current 'gold standard' they have to be verified against the existing standard. The aim of this study was to compare bone structural measures obtained from 3D microCT data sets with those obtained by stereology performed on conventional histological sections...... tibial metaphysis. The biopsies were embedded in methylmetacrylate before microCT scanning in a Scanco microCT 40 scanner at a resolution of 20 x 20 x 20 microm3, and the 3D data sets were analysed with a computer program. After microCT scanning, 16 sections were cut from the central 2 mm of each biopsy...

  2. Tamoxifen-inducible gene deletion reveals a distinct cell type associated with trabecular bone, and direct regulation of PTHrP expression and chondrocyte morphology by Ihh in growth region cartilage.

    Science.gov (United States)

    Hilton, Matthew J; Tu, Xiaolin; Long, Fanxin

    2007-08-01

    Indian hedgehog (Ihh) controls multiple aspects of endochondral skeletal development by signaling to both chondrocytes and perichondrial cells. Previous efforts to delineate direct effects of Ihh on chondrocytes by Col2-Cre-mediated ablation of Smoothened (Smo, encoding a transmembrane protein indispensable for Ihh signaling) has been only partially successful, due to the inability to discriminate between chondrocytes and perichondrial cells. Here we report a transgenic line (Col2-Cre) expressing under the control of the Colalpha1(II) promoter an inert form of Cre that is activatable by exogenous tamoxifen (TM); TM administration at proper times during embryogenesis induced Cre activity in chondrocytes but not in the perichondrium. By using this mouse line, we deleted Smo within subsets of chondrocytes without affecting the perichondrium and found that Smo removal led to localized disruption of the expression of parathyroid hormone-related protein (PTHrP) and the morphology of chondrocytes. Unexpectedly, TM invariably induced Cre activity in a subset of cells associated with the trabecular bone surface of long bones. These cells, when genetically marked and cultured in vitro, were capable of producing bone nodules. Expression of the Col2-Cre transgene in these cells likely reflected the endogenous Colalpha1(II) promoter activity as similar cells were found to express the IIA isoform of Colalpha1(II) mRNA endogenously. In summary, the present study has not only provided evidence that Ihh signaling directly controls PTHrP expression and chondrocyte morphology in the growth region cartilage, but has also uncovered a distinct cell type associated with the trabecular bone that appears to possess osteogenic potential.

  3. Influence of estrogen deficiency and tibolone therapy on trabecular and cortical bone evaluated by computed radiography system in rats Influência da deficiência estrogênica e do tratamento com tibolona no osso trabecular e cortical avaliada pelo sistema de radiografia computadorizada em ratas

    Directory of Open Access Journals (Sweden)

    Ana Carolina Bergmann de Carvalho

    2012-03-01

    Full Text Available PURPOSE: To verify the effects of tibolone administration on trabecular and cortical bone of ovariectomized female rats by computed radiography system (CRS. METHODS: The experiment was performed on two groups of rats previously ovariectomized, one received tibolone (OVX+T while the other did not (OVX, those groups were compared to a control group (C not ovariectomized. Tibolone administration (1mg/day began thirty days after the ovariectomy and the treatment remained for five months. At last, the animals were euthanized and femurs and tibias collected. Computed radiographies of the bones were obtained and the digital images were used to determine the bone optical density and cortical thickness on every group. All results were statistically evaluated with significance set at POBJETIVO: Verificar o efeito da administração de tibolona no tecido ósseo cortical e trabecular de ratas castradas através de radiografia computadorizada. MÉTODOS: O experimento foi realizado em dois grupos de ratas previamente ooforectomizadas, onde um grupo recebeu tibolona (OVX+T e o outro não (OVX. Esses grupos foram comparados a um grupo controle (C não ooforectomizado. A administração de tibolona (1mg/dia começou trinta dias após a ooforectomia e o tratamento teve duração de cinco meses. No final, os animais foram mortos e fêmures e tibias coletados. As radiografias computadorizadas dos ossos foram obtidas e as imagens digitais usadas para determinar a densidade óssea e a espessura cortical em todos os grupos. Todos os resultados foram avaliados estatisticamente com significância estabelecida a 5%. RESULTADOS: A administração de tibolona mostrou ser benéfica apenas para análise densitométrica da cabeça do fêmur, apresentando maiores valores de densidade comparada ao grupo OVX. Nenhuma diferença significativa foi encontrada para espessura óssea cortical. CONCLUSÃO: A ooforectomia ocasionou perda óssea nas regiões analisadas e a tibolona

  4. Agreement between radiographic and photographic trabecular patterns

    International Nuclear Information System (INIS)

    Korstjens, C.M.; Geraets, W.G.M.; Stelt, P.F. van der; Spruijt, R.J.; Mosekilde, L.

    1998-01-01

    Purpose: It has been hypothesized that photographs can facilitate the interpretation of the radiographic characteristics of trabecular bone. The reliability of these photographic and radiographic approaches has been determined, as have various agreements between the two approaches and their correlations with biomechanical characteristics. Material and Methods: Fourteen vertebral bodies were obtained at autopsy from 6 women and 8 men aged 22-76 years. Photographs (n=28) and radiographs (n=28) were taken of midsagittal slices from the third lumbar vertebra. The radiographs and photographs were digitized and the geometric properties of the trabecular architecture were then determined with a digital images analysis technique. Information on the compressive strength and ash density of the vertebral body was also available. Results: The geometric properties of both radiographs and photographs could be measured with a high degree of reliability (Cronbach's α>0.85). Agreement between the radiographic and photographic approaches was mediocre as only the radiographic measurements showed insignificant correlations (p<0.05) with the biomechanical characteristics. We suggest that optical phenomena may result in the significant correlations between the photographs and the biomechanical characteristics. Conclusion: For digital image processing, radiography offers a superior description of the architecture of trabecular bone to that offered by photography. (orig.)

  5. Agreement between radiographic and photographic trabecular patterns

    Energy Technology Data Exchange (ETDEWEB)

    Korstjens, C.M.; Geraets, W.G.M.; Stelt, P.F. van der [Dept. of Oral Radiology, Academic Centre for Dentistry, Amsterdam (Netherlands); Spruijt, R.J. [Div. of Psychosocial Research and Epidemiology, Netherlands Cancer Inst., Amsterdam (Netherlands); Mosekilde, L. [Dept. of Cell Biology, Univ. of Aarhus (Denmark)

    1998-11-01

    Purpose: It has been hypothesized that photographs can facilitate the interpretation of the radiographic characteristics of trabecular bone. The reliability of these photographic and radiographic approaches has been determined, as have various agreements between the two approaches and their correlations with biomechanical characteristics. Material and Methods: Fourteen vertebral bodies were obtained at autopsy from 6 women and 8 men aged 22-76 years. Photographs (n=28) and radiographs (n=28) were taken of midsagittal slices from the third lumbar vertebra. The radiographs and photographs were digitized and the geometric properties of the trabecular architecture were then determined with a digital images analysis technique. Information on the compressive strength and ash density of the vertebral body was also available. Results: The geometric properties of both radiographs and photographs could be measured with a high degree of reliability (Cronbach`s {alpha}>0.85). Agreement between the radiographic and photographic approaches was mediocre as only the radiographic measurements showed insignificant correlations (p<0.05) with the biomechanical characteristics. We suggest that optical phenomena may result in the significant correlations between the photographs and the biomechanical characteristics. Conclusion: For digital image processing, radiography offers a superior description of the architecture of trabecular bone to that offered by photography. (orig.)

  6. Histological comparison of autograft, allograft-DBM, xenograft, and synthetic grafts in a trabecular bone defect: an experimental study in rabbits.

    Science.gov (United States)

    Athanasiou, Vasilis T; Papachristou, Dionysios J; Panagopoulos, Andreas; Saridis, Alkis; Scopa, Chrisoula D; Megas, Panagiotis

    2010-01-01

    Different types of bone-graft substitutes have been developed and are on the market worldwide to eliminate the drawbacks of autogenous grafting. This experimental animal study was undertaken to evaluate the different histological properties of various bone graft substitutes utilized in this hospital. Ninety New Zealand white rabbits were divided into six groups of 15 animals. Under general anesthesia, a 4.5 mm-wide hole was drilled into both the lateral femoral condyles of each rabbit, for a total of 180 condyles for analysis. The bone defects were filled with various grafts, these being 1) autograft, 2) DBM crunch allograft (Grafton), 3) bovine cancellous bone xenograft (Lubboc), 4) calcium phosphate hydroxyapatite substitute (Ceraform), 5) calcium sulfate substitute (Osteoset), and 6) no filling (control). The animals were sacrificed at 1, 3, and 6 months after implantation and tissue samples from the implanted areas were processed for histological evaluation. A histological grading scale was designed to determine the different histological parameters of bone healing. The highest histological grades were achieved with the use of cancellous bone autograft. Bovine xenograft (Lubboc) was the second best in the histological scale grading. The other substitutes (Grafton, Ceraform, Osteoset) had similar scores but were inferior to both allograft and xenograft. Bovine xenograft showed better biological response than the other bone graft substitutes; however, more clinical studies are necessary to determine its overall effectiveness.

  7. The antiarrhythmic peptide analog rotigaptide (ZP123) stimulates gap junction intercellular communication in human osteoblasts and prevents decrease in femoral trabecular bone strength in ovariectomized rats

    DEFF Research Database (Denmark)

    Jørgensen, Niklas Rye; Teilmann, Stefan Cuoni; Henriksen, Zanne

    2005-01-01

    Gap junctions play an important role in bone development and function, but the lack of pharmacological tools has hampered the gap junction research. The antiarrhythmic peptides stimulate gap junction communication between cardiomyocytes, but effects in noncardiac tissue are unknown. The purpose...... of this study was to examine whether antiarrhythmic peptides, which are small peptides increasing gap junctional conductivity, show specific binding to osteoblasts and investigate the effect of the stable analog rotigaptide (ZP123) on gap junctional intercellular communication in vitro and on bone mass...... and strength in vivo. Cell coupling and calcium signaling were assessed in vitro on human, primary, osteoblastic cells. In vivo effects of rotigaptide on bone strength and density were determined 4 wk after ovariectomy in rats treated with either vehicle, sc injection twice daily (300 nmol per kilogram body...

  8. Effects of short-term alendronate treatment on the three-dimensional microstructural, physical and mechanical properties of dog trabecular bone

    DEFF Research Database (Denmark)

    Hu, J; Ding, Ming; Søballe, K

    2002-01-01

    The bisphosphonate, alendronate, is well known for its potent inhibition of osteoclast-mediated bone resorption. It has been used clinically for the treatment of osteoporosis and has also recently been used to reduce osteolysis around prostheses in a canine revision model of implant loosening...... proximal humeri. These specimens were scanned using a high-resolution microcomputed tomography (micro-CT) system. From accurate data sets, three-dimensional microstructural properties were calculated and physical and mechanical properties were determined. Treatment with alendronate increased bone volume...

  9. Copas de metal trabecular y aloinjertos óseos impactados en defectos acetabulares graves. Resultados a los 2-4 años. [Impacted bone allografts and trabecular metal cups in severe acetabular bone defects: 2 to 4-year results.

    Directory of Open Access Journals (Sweden)

    Martín Buttaro

    2014-06-01

    Full Text Available In­tro­duc­ción: El objetivo principal es presentar la supervivencia del componente acetabular en pacientes con defectos graves reconstruidos con copas de metal trabecular combinadas con aloinjertos óseos impactados. Como objetivo secundario, se compararon estos resultados con los previamente obtenidos por los autores en defectos de similar gravedad utilizando anillos de reconstrucción y aloinjertos óseos. Materiales­ y­ Métodos:­ Se realizaron 20 cirugías de revisión en 19 pacientes (edad promedio 65 años, controlados, de forma prospectiva, con defectos acetabulares graves tipos 3A o 3B de Paprosky, por falla mecánica o infecciosa. El puntaje funcional promedio preoperatorio fue de 6,2 puntos, según la escala de Merle D ́Aubigne. Siempre se utilizaron copas de metal trabecular y aloinjertos óseos impactados. Resultados:­ A los 30 meses de seguimiento promedio (rango 24-48 meses, la supervivencia del componente acetabular fue del 95% (IC = 75%-98%. Un paciente presentó un aflojamiento acetabular por infección profunda a las 16 semanas de la revisión y fue tratado con una artroplastia de resección. El puntaje funcional promedio, excluido el caso con aflojamiento posoperatorio, fue de 16,2 puntos. Se observó la incorporación de los aloinjertos óseos en todos los pacientes, salvo el caso con infección profunda. La comparación con nuestras series históricas reconstruidas con anillos de Kerboull o con anillos GAP arrojó resultados altamente favorables a favor de las copas de metal trabecular.  Conclusiones: Las copas de metal trabecular asociadas a aloinjertos óseos impactados ofrecen una alternativa válida en cirugía de revisión acetabular con defectos graves del capital óseo. Este método se asocia a resultados más favorables que los obtenidos antes con anillos de reconstrucción.

  10. Mucopolysaccharides in the trabecular meshwork

    International Nuclear Information System (INIS)

    Ohnishi, Yoshitaka; Yamana, Yasuo; Abe, Masahiro

    1982-01-01

    The localization of 35 S-sulfate and 3 H-glucosamine in the trabecular region of the hamster was studied by light and electron microscopic autoradiography after the intraperitoneal injection. Exposed silver grains of 35 S-sulfate were concentrated in the trabecular meshwork, sclera and cornea, and grains of 35 H-glucosamine were localized in the trabecular region. The radioactivity of both isotopes was observed in the Golgi apparatuses of the endothelial cells and fibroblasts in Schlemm's canal and the trabecular meshwork. Thereafter, the grains were noted over the entire cytoplasm, except for the nucleus, and then were incorporated into the amorphous substance and collagen fibers in the juxtacanalicular connective tissue. These results suggest that endothelial cells in the trabecular region synthesize and secrete the sulfated mucopolysaccharides and hyaluronic acid. (author)

  11. Concentration dependence of fluorine impurity spin-lattice relaxation rate in bone mineral

    International Nuclear Information System (INIS)

    Code, R.F.; Armstrong, R.L.; Cheng, P.-T.

    1992-01-01

    The concentration dependence of the fluoride ion spin-lattice relaxation rate has been observed by nuclear magnetic resonance experiments on samples of defatted and dried bone. The 19 F spin-lattice relaxation rates increased linearly with bone fluoride concentration. Different results were obtained from trabecular than from cortical bone. For the same macroscopic fluoride content per gram of bone calcium, relaxation rate is significantly faster in cortical bone. Relaxation rates in cortical bone samples prepared from rats and dogs were apparently controlled by the same species-independent processes. For samples from beagle dogs, bulk fluoride concentrations measured by neutron activation analysis were 3.1±0.3 times greater in trabecular bone than in corresponding cortical bone. The beagle spin-lattice relaxation data suggest that microscopic fluoride concentrations in bone mineral were 1.8±0.4 times greater in trabecular bone than in cortical bone. It is concluded that accumulation of fluoride impurities in bone mineral is non-uniform. (author)

  12. Dependences of Ultrasonic Parameters for Osteoporosis Diagnosis on Bone Mineral Density

    International Nuclear Information System (INIS)

    Hwang, Kyo Seung; Kim, Yoon Mi; Park, Jong Chan; Choi, Min Joo; Lee, Kang Il

    2012-01-01

    Quantitative ultrasound technologies for osteoporosis diagnosis measure ultrasonic parameters such as speed of sound(SOS) and normalized broadband ultrasound attenuation(nBUA) in the calcaneus (heel bone). In the present study, the dependences of SOS and nBUA on bone mineral density in the proximal femur with high risk of fracture were investigated by using 20 trabecular bone samples extracted from bovine femurs. SOS and nBUA in the femoral trabecular bone samples were measured by using a transverse transmission method with one matched pair of ultrasonic transducers with a center frequency of 1.0 MHz. SOS and nBUA measured in the 20 trabecular bone samples exhibited high Pearson's correlation coefficients (r) of r = 0.83 and 0.72 with apparent bone density, respectively. The multiple regression analysis with SOS and nBUA as independent variables and apparent bone density as a dependent variable showed that the correlation coefficient r = 0.85 of the multiple linear regression model was higher than those of the simple linear regression model with either parameter SOS or nBUA as an independent variable. These high linear correlations between the ultrasonic parameters and the bone density suggest that the ultrasonic parameters measured in the femur can be useful for predicting the femoral bone mineral density.

  13. Attenuating trabecular morphology associated with low magnesium diet evaluated using micro computed tomography.

    Directory of Open Access Journals (Sweden)

    Shu-Ju Tu

    Full Text Available The literature shows that bone mineral density (BMD and the geometric architecture of trabecular bone in the femur may be affected by inadequate dietary intake of Mg. In this study, we used microcomputed tomography (micro-CT to characterize and quantify the impact of a low-Mg diet on femoral trabecular bones in mice.Four-week-old C57BL/6J male mice were randomly assigned to 2 groups and supplied either a normal or low-Mg diet for 8weeks. Samples of plasma and urine were collected for biochemical analysis, and femur tissues were removed for micro-CT imaging. In addition to considering standard parameters, we regarded trabecular bone as a cylindrical rod and used computational algorithms for a technical assessment of the morphological characteristics of the bones. BMD (mg-HA/cm3 was obtained using a standard phantom.We observed a decline in the total tissue volume, bone volume, percent bone volume, fractal dimension, number of trabecular segments, number of connecting nodes, bone mineral content (mg-HA, and BMD, as well as an increase in the structural model index and surface-area-to-volume ratio in low-Mg mice. Subsequently, we examined the distributions of the trabecular segment length and radius, and a series of specific local maximums were identified. The biochemical analysis revealed a 43% (96% decrease in Mg and a 40% (71% decrease in Ca in plasma (urine excretion.This technical assessment performed using micro-CT revealed a lower population of femoral trabecular bones and a decrease in BMD at the distal metaphysis in the low-Mg mice. Examining the distributions of the length and radius of trabecular segments showed that the average length and radius of the trabecular segments in low-Mg mice are similar to those in normal mice.

  14. Variability of morphometric parameters of human trabecular tissue from coxo-arthritis and osteoporotic samples

    Directory of Open Access Journals (Sweden)

    Franco Marinozzi

    2012-01-01

    Full Text Available Morphometric and architectural bone parameters change in diseases such as osteoarthritis and osteoporosis. The mechanical strength of bone is primarily influenced by bone quantity and quality. Bone quality is defined by parameters such as trabecular thickness, trabecular separation, trabecular density and degree of anisotropy that describe the micro-architectural structure of bone. Recently, many studies have validated microtomography as a valuable investigative technique to assess bone morphometry, thanks to micro-CT non-destructive, non-invasive and reliability features, in comparison to traditional techniques such as histology. The aim of this study is the analysis by micro-computed tomography of six specimens, extracted from patients affected by osteoarthritis and osteoporosis, in order to observe the tridimensional structure and calculate several morphometric parameters.

  15. Anorexia Nervosa: Analysis of Trabecular Texture with CT.

    Science.gov (United States)

    Tabari, Azadeh; Torriani, Martin; Miller, Karen K; Klibanski, Anne; Kalra, Mannudeep K; Bredella, Miriam A

    2017-04-01

    Purpose To determine indexes of skeletal integrity by using computed tomographic (CT) trabecular texture analysis of the lumbar spine in patients with anorexia nervosa and normal-weight control subjects and to determine body composition predictors of trabecular texture. Materials and Methods This cross-sectional study was approved by the institutional review board and compliant with HIPAA. Written informed consent was obtained. The study included 30 women with anorexia nervosa (mean age ± standard deviation, 26 years ± 6) and 30 normal-weight age-matched women (control group). All participants underwent low-dose single-section quantitative CT of the L4 vertebral body with use of a calibration phantom. Trabecular texture analysis was performed by using software. Skewness (asymmetry of gray-level pixel distribution), kurtosis (pointiness of pixel distribution), entropy (inhomogeneity of pixel distribution), and mean value of positive pixels (MPP) were assessed. Bone mineral density and abdominal fat and paraspinal muscle areas were quantified with quantitative CT. Women with anorexia nervosa and normal-weight control subjects were compared by using the Student t test. Linear regression analyses were performed to determine associations between trabecular texture and body composition. Results Women with anorexia nervosa had higher skewness and kurtosis, lower MPP (P anorexia nervosa. Conclusion Patients with anorexia nervosa had increased skewness and kurtosis and decreased entropy and MPP compared with normal-weight control subjects. These parameters were associated with lowest lifetime weight and duration of amenorrhea, but there were no such associations with bone mineral density. These findings suggest that trabecular texture analysis might contribute information about bone health in anorexia nervosa that is independent of that provided with bone mineral density. © RSNA, 2016.

  16. Age-related differences in the bone mineralization pattern of rats following exercise

    International Nuclear Information System (INIS)

    McDonald, R.; Hegenauer, J.; Saltman, P.

    1986-01-01

    The effect of 12 weeks of treadmill exercise on the mineralization of trabecular and cortical bone was studied in rats 7, 14, and 19 months of age. Bone mineralization was evaluated by measuring concentrations of Ca, Mg, and hydroxyproline as well as uptake of 45Ca concentration in the femur, humerus, rib and calvaria. The 7- and 14-month-old rats increased mineralization in those cortical bones directly involved in exercise. The 19-month animal responded to exercise by increasing mineralization in all bones examined, including the nonweight bearing trabecular calvaria and cortical rib. From these data, it is apparent that the older animals undergo a total skeletal mineralization in response to exercise compared with local adaptation in the younger animal. Further, we provide evidence to support the use of the rat as a model in which to study mammalian bone physiology during the aging process

  17. Trabecular mineral content of the spine in women with hip fracture: CT measurement

    International Nuclear Information System (INIS)

    Firooznia, H.; Rafii, M.; Golimbu, C.; Schwartz, M.S.; Ort, P.

    1986-01-01

    The trabecular bone mineral content (BMC) of the spine was measured by computed tomography in 185 women aged 47-84 years with vertebral fracture (n = 74), hip fracture (n = 83), and both vertebral and hip fracture (n = 28). Eighty-seven percent of vertebral-fracture patients, 38% of hip-fracture patients, and 82% of vertebral- and hip-fracture patients had spinal BMC values below the fifth percentile for healthy premenopausal women and values 64%, 9%, and 68% below the fifth percentile for age-matched control subjects. No significant loss of spinal trabecular bone was seen in patients with hip fracture. If it is assumed that the rate of trabecular bone loss is the same in the spine and femoral neck, then hip fracture (unlike osteoporotic vertebral fracture) is not associated with disproportionate loss of trabecular bone. Hip fracture occurs secondary to weakening of bone and increased incidence of falls. Bone weakening may be due to disproportionate loss of trabecular or cortical bone, proportionate loss of both, or other as yet undetermined qualitative changes in bone

  18. Evaluation of the efficacy of zoledronic acid and amifostine on radiation induced bone loss in mice

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Wook; Lee, Sueum; Kang, Sohi; Moon, Cahng Jong; Kim, Jong Choon; Kim, Sung Ho [College of Veterinary Medicine, Chonnam National University, Gwangju (Korea, Republic of); Jung, Uhee; Jo, Sung Kee [Advanced Radiation Technology Institute, Jeungeup (Korea, Republic of); Jang, Jong Sik [College of Ecology and Environmental Science, Kyungpook National University, Sangju (Korea, Republic of)

    2016-09-15

    This study investigated the effects of zoledronic acid (ZA) on radiation-induced bone loss in C3H/HeN mice. C3H/HeN mice were divided into sham control and three irradiated groups (3 Gy, gamma ray). The irradiated mice were treated for 12 weeks with vehicle, amifostine (intraperitoneal injection), or ZA (subcutaneous injection). Grip strength, uterus weight, and serum alkaline phosphatase (ALP), and tartrate-resistant acid phosphatase (TRAP) levels were measured. Tibiae were analyzed using micro-computed tomography. Treatment of ZA (100 μg·kg{sup -1}·week{sup -1}) significantly preserved trabecular bone volume, trabecular thickness, trabecular number, trabecular separation, bone mineral density of proximal tibia metaphysic, and cortical bone volume, but did not alter the uterus weight of the mice. The administration of ZA for 12 weeks lowered serum ALP and TRAP levels in irradiated mice, suggesting that ZA can reduce the bone turnover rate in mice. No differences were apparent between the amifostine-treated group and the irradiation control group. The results indicate that ZA can prevent radiation-induced bone loss in mice.

  19. Trabecular evidence for a human-like gait in Australopithecus africanus.

    Directory of Open Access Journals (Sweden)

    Meir M Barak

    Full Text Available Although the earliest known hominins were apparently upright bipeds, there has been mixed evidence whether particular species of hominins including those in the genus Australopithecus walked with relatively extended hips, knees and ankles like modern humans, or with more flexed lower limb joints like apes when bipedal. Here we demonstrate in chimpanzees and humans a highly predictable and sensitive relationship between the orientation of the ankle joint during loading and the principal orientation of trabecular bone struts in the distal tibia that function to withstand compressive forces within the joint. Analyses of the orientation of these struts using microCT scans in a sample of fossil tibiae from the site of Sterkfontein, of which two are assigned to Australopithecus africanus, indicate that these hominins primarily loaded their ankles in a relatively extended posture like modern humans and unlike chimpanzees. In other respects, however, trabecular properties in Au africanus are distinctive, with values that mostly fall between those of chimpanzees and humans. These results indicate that Au. africanus, like Homo, walked with an efficient, extended lower limb.

  20. Electron absorbed fractions in skeletal soft tissues based on red bone marrow segmentation at runtime in muCT images of human trabecular bone;Fracoes absorvidas de eletrons em tecidos moles do esqueleto avaliadas com base na segmentacao em tempo de execucao da medula ossea vermelha contida em imagens muCT do osso trabecular humano

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, J.W. [Instituto Federal de Educacao, Ciencia e Tecnologia de Pernambuco, Recife, PE (Brazil); Kramer, R. [Universidade de Pernambuco (UPE), Recife, PE (Brazil). Escola Politecnica; Khoury, H.J. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Robson-Brown, K. [University of Bristol, Bristol (United Kingdom). Dept. of Archaeology and Anthropology

    2009-07-01

    Skeletal dosimetry determines equivalent dose or absorbed fractions in the red bone marrow (RBM) and the osteogenic cells on bone surfaces (BSC). Following a method used earlier for the BSC, RBM and yellow bone marrow (YBM) have been segmented in the marrow cavities of muCT images of human spongiosa at runtime, i.e. during the execution of the Monte Carlo calculation, which avoids the necessity to segment RBM and YBM externally in muCT images for many different cellularities and to store the data. Using this internal RBM/YBM segmentation, this study presents electron absorbed fractions for the RBM and the BSC as a function of the voxel resolution and also compares the results with data from other investigations. (author)

  1. Bone mineral content in the senescent rat femur: an assessment using single photon absorptiometry

    International Nuclear Information System (INIS)

    Kiebzak, G.M.; Smith, R.; Howe, J.C.; Sacktor, B.

    1988-01-01

    The single photon absorptiometry technique was evaluated for measuring bone mineral content (BMC) of the excised femurs of the rat, and the system was used to examine the changes in cortical and trabecular bone from young adult (6 mo), mature adult (12 mo), and senescent (24 mo) male and female animals. BMC of the femur midshaft, representing cortical bone, apparently increased progressively with advancing age. The width of the femur at the scan site also increased with age. Normalizing the midshaft BMC by width partially compensated for the age-associated increase. However, when bone mineral values were normalized by the cortical area at the scan site, to take into account the geometric differences in the femurs of different aged animals, maximum bone densities were found in the mature adult and these values decreased slightly in the femurs from senescent rats. In contrast, the BMC of the femur distal metaphysis, representing trabecular bone, decreased markedly in the aged rat. The loss of trabecular bone was also evident from morphological examination of the distal metaphysis. These findings indicated that bone mineral loss with age was site specific in the rat femur. These studies provided additional evidence that the rat might serve as a useful animal model for specific experiments related to the pathogenesis of age-associated osteopenia

  2. Clinical relevance of the apparent diffusion coefficient value of metastatic bone tumours on diffusion-weighted MRI images: differences according to the types of primary tumour, the affected bones, and clinical factors.

    Science.gov (United States)

    Cha, M J; Yoon, Y C

    2015-10-01

    To evaluate whether the apparent diffusion coefficient (ADC) of metastatic bone tumours on diffusion-weighted magnetic resonance imaging (MRI) images differs according to the type of primary cancer, the affected bone, and clinical factors. For this retrospective study, two radiologists reviewed MRI images, including ADC maps, of 67 patients (M:F=38:29; median age, 48 years) who were diagnosed with bone metastasis by means of histological or clinical confirmation. The primary tumours included 29 lung adenocarcinomas, 15 invasive ductal adenocarcinomas of the breast, 13 hepatocellular carcinomas, six prostatic carcinomas, and four renal cell carcinomas. ADC values of the metastatic tumour were compared according to the type of primary malignancy, the affected bone, and the age and sex of the patient using Kruskal-Wallis and Mann-Whitney U-tests with Bonferroni correction. In addition, pre-contrast CT images were available in 38 of 67 patients; a subanalysis of the CT radiodensity and ADC values were performed with Spearman correlation. The mean, standard deviation, and minimum and maximum values of the ADC of metastatic bone tumours did not differ significantly according to type of primary malignancy, the affected bone, or clinical variables (p>0.1). The ADC value was not significantly correlated with CT radiodensity (p=0.24). Intra- and interobserver agreements for the mean ADC values were excellent (intra-observer: p=0.98; interobserver: p=0.98). Assessment of the ADC value of metastatic bone tumours is not reliable for differentiation of the type of primary cancer. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  3. Assessment of treatment response by total tumor volume and global apparent diffusion coefficient using diffusion-weighted MRI in patients with metastatic bone disease: a feasibility study.

    Directory of Open Access Journals (Sweden)

    Matthew D Blackledge

    Full Text Available We describe our semi-automatic segmentation of whole-body diffusion-weighted MRI (WBDWI using a Markov random field (MRF model to derive tumor total diffusion volume (tDV and associated global apparent diffusion coefficient (gADC; and demonstrate the feasibility of using these indices for assessing tumor burden and response to treatment in patients with bone metastases. WBDWI was performed on eleven patients diagnosed with bone metastases from breast and prostate cancers before and after anti-cancer therapies. Semi-automatic segmentation incorporating a MRF model was performed in all patients below the C4 vertebra by an experienced radiologist with over eight years of clinical experience in body DWI. Changes in tDV and gADC distributions were compared with overall response determined by all imaging, tumor markers and clinical findings at serial follow up. The segmentation technique was possible in all patients although erroneous volumes of interest were generated in one patient because of poor fat suppression in the pelvis, requiring manual correction. Responding patients showed a larger increase in gADC (median change = +0.18, range = -0.07 to +0.78 × 10(-3 mm2/s after treatment compared to non-responding patients (median change = -0.02, range = -0.10 to +0.05 × 10(-3 mm2/s, p = 0.05, Mann-Whitney test, whereas non-responding patients showed a significantly larger increase in tDV (median change = +26%, range = +3 to +284% compared to responding patients (median change = -50%, range = -85 to +27%, p = 0.02, Mann-Whitney test. Semi-automatic segmentation of WBDWI is feasible for metastatic bone disease in this pilot cohort of 11 patients, and could be used to quantify tumor total diffusion volume and median global ADC for assessing response to treatment.

  4. Insulin Resistance Is Associated With Smaller Cortical Bone Size in Nondiabetic Men at the Age of Peak Bone Mass.

    Science.gov (United States)

    Verroken, Charlotte; Zmierczak, Hans-Georg; Goemaere, Stefan; Kaufman, Jean-Marc; Lapauw, Bruno

    2017-06-01

    In type 2 diabetes mellitus, fracture risk is increased despite preserved areal bone mineral density. Although this apparent paradox may in part be explained by insulin resistance affecting bone structure and/or material properties, few studies have investigated the association between insulin resistance and bone geometry. We aimed to explore this association in a cohort of nondiabetic men at the age of peak bone mass. Nine hundred ninety-six nondiabetic men aged 25 to 45 years were recruited in a cross-sectional, population-based sibling pair study at a university research center. Insulin resistance was evaluated using the homeostasis model assessment of insulin resistance (HOMA-IR), with insulin and glucose measured from fasting serum samples. Bone geometry was assessed using peripheral quantitative computed tomography at the distal radius and the radial and tibial shafts. In age-, height-, and weight-adjusted analyses, HOMA-IR was inversely associated with trabecular area at the distal radius and with cortical area, periosteal and endosteal circumference, and polar strength strain index at the radial and tibial shafts (β ≤ -0.13, P insulin-like growth factor 1, or sex steroid levels. In this cohort of nondiabetic men at the age of peak bone mass, insulin resistance is inversely associated with trabecular and cortical bone size. These associations persist after adjustment for body composition, muscle size or function, or sex steroid levels, suggesting an independent effect of insulin resistance on bone geometry. Copyright © 2017 Endocrine Society

  5. Cortical and trabecular bone microstructure did not recover at weight-bearing skeletal sites and progressively deteriorated at non-weight-bearing sites during the year following international space station missions

    NARCIS (Netherlands)

    Vico, L.; van Rietbergen, B.; Vilayphiou, N.; Linossier, M.T.; Locrelle, H.; Normand, M.; Zouch, M.; Gerbaix, M.; Bonnet, N.; Novikov, V.; Thomas, T.; Vassilieva, G.

    2017-01-01

    Risk for premature osteoporosis is a major health concern in astronauts and cosmonauts; the reversibility of the bone lost at the weight-bearing bone sites is not established, although it is suspected to take longer than the mission length. The bone three-dimensional structure and strength that

  6. Chronic alcohol abuse in men alters bone mechanical properties by affecting both tissue mechanical properties and microarchitectural parameters.

    Science.gov (United States)

    Cruel, M; Granke, M; Bosser, C; Audran, M; Hoc, T

    2017-06-01

    Alcohol-induced secondary osteoporosis in men has been characterized by higher fracture prevalence and a modification of bone microarchitecture. Chronic alcohol consumption impairs bone cell activity and results in an increased fragility. A few studies highlighted effects of heavy alcohol consumption on some microarchitectural parameters of trabecular bone. But to date and to our knowledge, micro- and macro-mechanical properties of bone of alcoholic subjects have not been investigated. In the present study, mechanical properties and microarchitecture of trabecular bone samples from the iliac crest of alcoholic male patients (n=15) were analyzed and compared to a control group (n=8). Nanoindentation tests were performed to determine the tissue's micromechanical properties, micro-computed tomography was used to measure microarchitectural parameters, and numerical simulations provided the apparent mechanical properties of the samples. Compared to controls, bone tissue from alcoholic patients exhibited an increase of micromechanical properties at tissue scale, a significant decrease of apparent mechanical properties at sample scale, and significant changes in several microarchitectural parameters. In particular, a crucial role of structure model index (SMI) on mechanical properties was identified. 3D microarchitectural parameters are at least as important as bone volume fraction to predict bone fracture risk in the case of alcoholic patients. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  7. Revision total knee arthroplasty with the use of trabecular metal cones

    DEFF Research Database (Denmark)

    Jensen, Claus L; Petersen, Michael Mygind; Schrøder, Henrik

    2012-01-01

    "Trabecular Metal Cone" (TM Cone) (Zimmer, Inc, Warsaw, Ind) for reconstruction of bone loss in the proximal tibia during revision total knee arthroplasty is now optional. Forty patients were randomized to receive revision total knee arthroplasty with or without TM Cone (No TM Cone). The Anderson...

  8. Is multidetector CT-based bone mineral density and quantitative bone microstructure assessment at the spine still feasible using ultra-low tube current and sparse sampling?

    Energy Technology Data Exchange (ETDEWEB)

    Mei, Kai; Kopp, Felix K.; Schwaiger, Benedikt J.; Gersing, Alexandra S.; Sauter, Andreas; Muenzel, Daniela; Rummeny, Ernst J. [Klinikum rechts der Isar, Technische Universitaet Muenchen, Department of Diagnostic and Interventional Radiology, Munich (Germany); Bippus, Rolf [Research Laboratories, Philips GmbH Innovative Technologies, Hamburg (Germany); Koehler, Thomas [Research Laboratories, Philips GmbH Innovative Technologies, Hamburg (Germany); Technische Universitaet Muenchen, TUM Institute for Advanced Studies, Garching (Germany); Fehringer, Andreas [Technische Universitaet Muenchen, Lehrstuhl fuer Biomedizinische Physik, Garching (Germany); Pfeiffer, Franz [Klinikum rechts der Isar, Technische Universitaet Muenchen, Department of Diagnostic and Interventional Radiology, Munich (Germany); Technische Universitaet Muenchen, TUM Institute for Advanced Studies, Garching (Germany); Technische Universitaet Muenchen, Lehrstuhl fuer Biomedizinische Physik, Garching (Germany); Kirschke, Jan S. [Klinikum rechts der Isar, Technische Universitaet Muenchen, Section of Diagnostic and Interventional Neuroradiology, Munich (Germany); Noel, Peter B. [Klinikum rechts der Isar, Technische Universitaet Muenchen, Department of Diagnostic and Interventional Radiology, Munich (Germany); Technische Universitaet Muenchen, Lehrstuhl fuer Biomedizinische Physik, Garching (Germany); Baum, Thomas [Klinikum rechts der Isar, Technische Universitaet Muenchen, Department of Diagnostic and Interventional Radiology, Munich (Germany); Klinikum rechts der Isar, Technische Universitaet Muenchen, Section of Diagnostic and Interventional Neuroradiology, Munich (Germany)

    2017-12-15

    Osteoporosis diagnosis using multidetector CT (MDCT) is limited to relatively high radiation exposure. We investigated the effect of simulated ultra-low-dose protocols on in-vivo bone mineral density (BMD) and quantitative trabecular bone assessment. Institutional review board approval was obtained. Twelve subjects with osteoporotic vertebral fractures and 12 age- and gender-matched controls undergoing routine thoracic and abdominal MDCT were included (average effective dose: 10 mSv). Ultra-low radiation examinations were achieved by simulating lower tube currents and sparse samplings at 50%, 25% and 10% of the original dose. BMD and trabecular bone parameters were extracted in T10-L5. Except for BMD measurements in sparse sampling data, absolute values of all parameters derived from ultra-low-dose data were significantly different from those derived from original dose images (p<0.05). BMD, apparent bone fraction and trabecular thickness were still consistently lower in subjects with than in those without fractures (p<0.05). In ultra-low-dose scans, BMD and microstructure parameters were able to differentiate subjects with and without vertebral fractures, suggesting osteoporosis diagnosis is feasible. However, absolute values differed from original values. BMD from sparse sampling appeared to be more robust. This dose-dependency of parameters should be considered for future clinical use. (orig.)

  9. Is multidetector CT-based bone mineral density and quantitative bone microstructure assessment at the spine still feasible using ultra-low tube current and sparse sampling?

    International Nuclear Information System (INIS)

    Mei, Kai; Kopp, Felix K.; Schwaiger, Benedikt J.; Gersing, Alexandra S.; Sauter, Andreas; Muenzel, Daniela; Rummeny, Ernst J.; Bippus, Rolf; Koehler, Thomas; Fehringer, Andreas; Pfeiffer, Franz; Kirschke, Jan S.; Noel, Peter B.; Baum, Thomas

    2017-01-01

    Osteoporosis diagnosis using multidetector CT (MDCT) is limited to relatively high radiation exposure. We investigated the effect of simulated ultra-low-dose protocols on in-vivo bone mineral density (BMD) and quantitative trabecular bone assessment. Institutional review board approval was obtained. Twelve subjects with osteoporotic vertebral fractures and 12 age- and gender-matched controls undergoing routine thoracic and abdominal MDCT were included (average effective dose: 10 mSv). Ultra-low radiation examinations were achieved by simulating lower tube currents and sparse samplings at 50%, 25% and 10% of the original dose. BMD and trabecular bone parameters were extracted in T10-L5. Except for BMD measurements in sparse sampling data, absolute values of all parameters derived from ultra-low-dose data were significantly different from those derived from original dose images (p<0.05). BMD, apparent bone fraction and trabecular thickness were still consistently lower in subjects with than in those without fractures (p<0.05). In ultra-low-dose scans, BMD and microstructure parameters were able to differentiate subjects with and without vertebral fractures, suggesting osteoporosis diagnosis is feasible. However, absolute values differed from original values. BMD from sparse sampling appeared to be more robust. This dose-dependency of parameters should be considered for future clinical use. (orig.)

  10. Trabecular meshwork stiffness in glaucoma.

    Science.gov (United States)

    Wang, Ke; Read, A Thomas; Sulchek, Todd; Ethier, C Ross

    2017-05-01

    Alterations in stiffness of the trabecular meshwork (TM) may play an important role in primary open-angle glaucoma (POAG), the second leading cause of blindness. Specifically, certain data suggest an association between elevated intraocular pressure (IOP) and increased TM stiffness; however, the underlying link between TM stiffness and IOP remains unclear and requires further study. We here first review the literature on TM stiffness measurements, encompassing various species and based on a number of measurement techniques, including direct approaches such as atomic force microscopy (AFM) and uniaxial tension tests, and indirect methods based on a beam deflection model. We also briefly review the effects of several factors that affect TM stiffness, including lysophospholipids, rho-kinase inhibitors, cytoskeletal disrupting agents, dexamethasone (DEX), transforming growth factor-β 2 (TGF-β 2 ), nitric oxide (NO) and cellular senescence. We then describe a method we have developed for determining TM stiffness measurement in mice using a cryosection/AFM-based approach, and present preliminary data on TM stiffness in C57BL/6J and CBA/J mouse strains. Finally, we investigate the relationship between TM stiffness and outflow facility between these two strains. The method we have developed shows promise for further direct measurements of mouse TM stiffness, which may be of value in understanding mechanistic relations between outflow facility and TM biomechanical properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Quantification of age-related changes in the structure model type and trabecular thickness of human tibial cancellous

    DEFF Research Database (Denmark)

    Ding, Ming; Hvid, I

    2000-01-01

    Structure model type and trabecular thickness are important characteristics in describing cancellous bone architecture. It has been qualitatively observed that a radical change of trabeculae from plate-like to rod-like occurs in aging, bone remodeling, and osteoporosis. Thickness of trabeculae has...... traditionally been measured using model-based histomorphometric methods on two-dimensional (2-D) sections. However, no quantitative study has been published based on three-dimensional (3-D) methods on the age-related changes in structure model type and trabecular thickness for human peripheral (tibial......, structure model type and trabecular thickness were quantified by means of novel 3-D methods. Structure model type was assessed by calculating the structure model index (SMI). The SMI was quantified based on a differential analysis of the triangulated bone surface of a structure. This technique allows...

  12. Multielement analysis of iliac crest bone by neutron activation

    International Nuclear Information System (INIS)

    Aras, N.K.; Yilmaz, G.; Korkusuz, F.; Olmez, I.; Sepici, B.; Eksioglu, F.; Bode, P.

    2000-01-01

    Bone samples from iliac crest were obtained from apparently healthy female (n = 4) and male (n = 8) subjects with ages between 15-50. Cortical and trabecular parts were separated and soft tissues like fat, muscle and blood were removed. Calcium, Mg, Na, Cl, Fe, Zn, Br, Sr, and Cs were determined by instrumental neutron activation analysis and other techniques, and their relations were discussed. Fairly good agreement was obtained with literature data. These values may serve as reference values for subjects from a Turkish population. (author)

  13. A trabecular metal implant 4 months after placement: clinical-histologic case report.

    Science.gov (United States)

    Spinato, Sergio; Zaffe, Davide; Felice, Pietro; Checchi, Luigi; Wang, Hom-Lay

    2014-02-01

    The aim of this case report was to histologically evaluate the behavior of a trabecular metal (TM) implant composed of titanium and spatial 3-dimensional tantalum (Ta) trabeculae. This study is the first human histologic case report of this implant. A TM implant was placed in a 54-year-old woman exhibiting moderate chronic periodontitis. After periodontal treatment, the implant was inserted under favorable clinical conditions. Patient was not seen for 4 months because of unrelated breast reduction surgery. At the surgical reopening, periimplant inflammation affecting the coronal third of the implant was observed 4 months after implant placement. With patient's consent, the implant was removed for histologic analysis. Histology highlighted a greater amount of bone in close contact with Ta trabeculae than titanium surfaces. The finding of bone formation around the Ta trabeculae suggests that trabecular metal material promotes bone ingrowth for secondary implant stability. Additional evidence is needed to confirm this observation.

  14. Relationship of insulin-like growth factor 1 and bone parameters in 7–15 years old apparently, healthy Indian children

    Directory of Open Access Journals (Sweden)

    Veena H Ekbote

    2015-01-01

    Full Text Available Objective: Growth hormone through insulin-like growth factor 1 (IGF-1 plays an important role in both bone growth and mineralization. This cross-sectional study was carried out to evaluate the relationship between serum IGF-1 concentrations and dual energy X-ray (DXA measured whole body less head bone area (BA, lean body mass (LBM, and bone mineral content (BMC. Methods: One hundred and nineteen children (boys = 70, age = 7.3–15.6 years were studied for their anthropometric parameters by standard methods and bone and body composition by DXA. Their fasting serum IGF-1 concentrations were assessed by enzyme-linked immunosorbent assay and Z-scores were calculated using available reference data. Bone and body composition parameter Z-scores were calculated using ethnic reference data. Results: Mean age of the boys and girls was similar (11.5 ± 1.8 years. The mean serum IGF-1concentrations and IGF-1 Z-scores were similar (P > 0.1 between boys and girls and were of the order of (302.3 ± 140.0 and − 1.4 ± 1.1, respectively. The LBM for age and BA for age Z-score was greater in children with IGF-1 Z-score > median than children with IGF-1 Z-score 0.1. Conclusion: Serum IGF-1 levels were more strongly associated with BA and LBM, suggesting that its effect on bone is greater with respect to periosteal bone acquisition and through its effect on muscle mass.

  15. Material model of pelvic bone based on modal analysis: a study on the composite bone.

    Science.gov (United States)

    Henyš, Petr; Čapek, Lukáš

    2017-02-01

    Digital models based on finite element (FE) analysis are widely used in orthopaedics to predict the stress or strain in the bone due to bone-implant interaction. The usability of the model depends strongly on the bone material description. The material model that is most commonly used is based on a constant Young's modulus or on the apparent density of bone obtained from computer tomography (CT) data. The Young's modulus of bone is described in many experimental works with large variations in the results. The concept of measuring and validating the material model of the pelvic bone based on modal analysis is introduced in this pilot study. The modal frequencies, damping, and shapes of the composite bone were measured precisely by an impact hammer at 239 points. An FE model was built using the data pertaining to the geometry and apparent density obtained from the CT of the composite bone. The isotropic homogeneous Young's modulus and Poisson's ratio of the cortical and trabecular bone were estimated from the optimisation procedure including Gaussian statistical properties. The performance of the updated model was investigated through the sensitivity analysis of the natural frequencies with respect to the material parameters. The maximal error between the numerical and experimental natural frequencies of the bone reached 1.74 % in the first modal shape. Finally, the optimised parameters were matched with the data sheets of the composite bone. The maximal difference between the calibrated material properties and that obtained from the data sheet was 34 %. The optimisation scheme of the FE model based on the modal analysis data provides extremely useful calibration of the FE models with the uncertainty bounds and without the influence of the boundary conditions.

  16. Bone densitometry in healthy cats by quantitative computed tomography

    International Nuclear Information System (INIS)

    Oliveira, D.C.; Costa, L.A.V.S.; Teixeira, M.W.; Costa, F.S.; Cardoso, M.J.L.

    2012-01-01

    The radiodensity of the trabecular bone of the lumbar vertebrae in 16 healthy adult cats was studied using quantitative computed tomography (QCT). The average radiodensity of the trabecular bone of the second lumbar vertebra was 436.1 +- 42.1 Hounsfield units. However, there was a nonhomogeneous radiodensity distribution of the vertebral body. (author)

  17. Extrinsic Mechanisms Involved in Age-Related Defective Bone Formation

    DEFF Research Database (Denmark)

    Trinquier, Anne Marie-Pierre Emilie; Kassem, Moustapha

    2011-01-01

    Context: Age-related bone loss is associated with progressive changes in bone remodeling characterized by decreased bone formation relative to bone resorption. Both trabecular and periosteal bone formation decline with age in both sexes, which contributes to bone fragility and increased risk of f...

  18. Selection of bone samples for 239Pu analyses in man

    International Nuclear Information System (INIS)

    Jee, W.S.S.; Wronski, T.J.; Smith, J.M.; Kimmel, D.B.; Miller, S.C.; Stover, B.J.

    1981-01-01

    Studies on the skeletal macrodistribution, microdistribution, and toxicity of 239 Pu and studies on bone turnover rates show that trabecular bone sites with high turnover rates have the greatest affinity for 239 Pu. In the adult beagle, these high-turnover, trabecular bone sites also show a higher occurrence of osteosarcomas. Correspondingly, high-turnover bone sites in the human would include the ilium (pelvis) and lumbar vertebrae (LVB), sites that are readily obtainable at autopsy. We recommend that the trabecular bone of the ilium and of the LVB be sampled to determine the skeletal radionuclide content of humans

  19. CBFA1 and topoisomerase I mRNA levels decline during cellular aging of human trabecular osteoblasts

    DEFF Research Database (Denmark)

    Christiansen, Mette; Kveiborg, M.; Kassem, M.

    2000-01-01

    In order to understand the reasons for age-related impairment of the function of bone forming osteoblasts, we have examined the steady-state mRNA levels of the transcription factor CBFA1 and topoisomerase I during cellular aging of normal human trabecular osteoblasts, by the use of semiquantitati...

  20. Using Micro-CT Derived Bone Microarchitecture to Analyze Bone Stiffness - A Case Study on Osteoporosis Rat Bone

    Directory of Open Access Journals (Sweden)

    Yuchin eWu

    2015-05-01

    Full Text Available Micro-computed tomography images can be used to quantitatively represent bone geometry through a range of computed attenuation-based parameters. Nonetheless, those parameters remain indirect indices of bone micro-architectural strength and require further computational tools to interpret bone structural stiffness and potential for mechanical failure. Finite element analysis (FEA can be applied to measure trabecular bone stiffness and potentially predict the location of structural failure in preclinical animal models of osteoporosis, although that procedure from image segmentation of micro-CT derived bone geometry to FEA is often challenging and computationally expensive, resulting in failure of the model to build. Notably, the selection of resolution and threshold for bone segmentation are key steps that greatly affect computational complexity and validity. In the following study, we evaluated an approach whereby Micro-CT derived greyscale attenuation and segmentation data guided the selection of trabecular bone for analysis by FEA. We further correlated those FEA results to both two and three dimensional bone microarchitecture from sham and ovariectomized (OVX rats (n=10/group. A virtual cylinder of vertebral trabecular bone 40% in length from the caudal side was selected for FEA because micro-CT based image analysis indicated the largest differences in microarchitecture between the two groups resided there. Bone stiffness was calculated using FEA and statistically correlated with the three dimensional values of bone volume/tissue volume, bone mineral density, fractal dimension, trabecular separation and trabecular bone pattern factor. Our method simplified the process for the assessment of trabecular bone stiffness by FEA from Micro-CT images and highlighted the importance of bone microarchitecture in conferring significantly increased bone quality capable of resisting failure due to increased mechanical loading.

  1. Bone mineral content (BMC) of the lumbar vertebrae (L2-L4) measured by quantitative computed tomography (QCT) and dual energy X-ray absorptiometry (DXA) in 21 hemodialysis (HD) patients

    International Nuclear Information System (INIS)

    Takahashi, Nobuyoshi; Suzuki, Tadashi; Sato, Motoaki; Oh, Songchol; Sato, Atsushi; Saito, Hisao; Funyu, Tomihisa.

    1996-01-01

    BMC of lumbar vertebrae (L2-L4) was measured by QCT and DXA in 21 HD patients. The effect of sex, aging, HD duration, postmenopausal years and various blood parameters of bone metabolism on BMC was assessed statistically. BMC showed a good positive correlation not only with DXA and QCT (trabecular and cortical bone), but with QCT (trabecular bone) and QCT (cortical bone). A significant age-related decrease in BMC, particularly by QCT (trabecular bone), was found in both sexes. BMC measured by QCT (trabecular bone) increased with the duration of HD in male patients. A negative relationship between postmenopausal years and BMC measured by QCT (trabecular and cortical bone) was prominent. BMC was not found to be correlated with various blood parameters of bone metabolism. Thus, measurement of BMC (L2-L4) by QCT has the advantage of allowing more precise examination of changes in cortical and trabecular bone. (author)

  2. Bone densitometry

    DEFF Research Database (Denmark)

    Ravn, Pernille; Alexandersen, P; Møllgaard, A

    1999-01-01

    The bisphosphonates have been introduced as alternatives to hormone replacement therapy (HRT) for the treatment and prevention of postmenopausal osteoporosis. The expected increasing application in at clinical practice demands cost-effective and easily handled methods to monitor the effect on bone....... The weak response at the distal forearm during antiresorptive treatment has restricted the use of bone densitometry at this region. We describe a new model for bone densitometry at the distal forearm, by which the response obtained is comparable to the response in other regions where bone densitometry...... is much more expensive and technically complicated. By computerized iteration of single X-ray absorptiometry forearm scans we defined a region with 65% trabecular bone. The region was analyzed in randomized, double-masked, placebo- controlled trials: a 2-year trial with alendronate (n = 69), a 1-year...

  3. Evaluation of increasing levels of a microbial phytase in phosphorus deficient broiler diets via live broiler performance, tibia bone ash, apparent metabolizable energy, and amino acid digestibility.

    Science.gov (United States)

    Pieniazek, J; Smith, K A; Williams, M P; Manangi, M K; Vazquez-Anon, M; Solbak, A; Miller, M; Lee, J T

    2017-02-01

    The objective was to investigate increasing concentrations of an evolved microbial phytase on male broiler performance, tibia bone ash, AME, and amino acid digestibility when fed diets deficient in available phosphorus (aP). Experiment 1 evaluated the effects of phytase during a 21 d battery cage study and Experiment 2 was a 42 d grow-out. Experiment 1 included six treatments; negative control (NC) with an aP level of 0.23% (starter) and 0.19% (grower), two positive controls (PC) consisting of an additional 0.12% and 0.22% aP (PC 1 and PC 2), and the NC supplemented with three levels of phytase (250, 500, and 2,000 U/kg). The NC diet reduced (P Phytase increased (P phytase yielding similar results to the PC2, and improved FCR and increased bone ash was observed at all phytase levels. Amino acid digestibility coefficients were increased (P phytase at 250 U/kg. Phytase at all rates increased (P phytase inclusion of 250, 500, and 2000 U/kg, respectively. Experiment 2 included a PC consisting of 0.45%, 0.41%, and 0.38% aP for the starter, grower, and finisher, respectively; NC with reduced aP of 0.17%; and phytase at 500 and 2,000 U/kg. Phytase increased BW (P phytase resulted in further BW increases compared to the PC (starter and grower). Phytase improved FCR to levels comparable to the PC, with supplementation at 2,000 U/kg resulting in improvements beyond the PC in the starter phase. Amino acid digestibility coefficients were increased with phytase at 2,000 U/kg to levels comparable to that of the PC. These data confirm that the inclusion of phytase improves broiler performance and bone mineralization in aP reduced diets and levels beyond the traditional 500 U/kg can result in further improvements. © 2016 Poultry Science Association Inc.

  4. [Analysis of correlation between trabecular microstructure and clinical imaging parameters in fracture region of osteoporotic hip].

    Science.gov (United States)

    Peng, Jing; Zhou, Yong; Min, Li; Zhang, Wenli; Luo, Yi; Zhang, Xuelei; Zou, Chang; Shi, Rui; Tu, Chongqi

    2014-05-01

    To analyze the correlation between the trabecular microstructure and the clinical imaging parameters in the fracture region of osteoporotic hip so as to provide a simple method to evaluate the trabecular microstructure by a non-invasive way. Between June 2012 and January 2013, 16 elderly patients with femoral neck fracture underwent hip arthroplasty were selected as the trial group; 5 young patients with pelvic fracture were selected as the control group. The hip CT examination was done, and cancellous bone volume/marrow cavity volume (CV/MV) was analyzed with Mimics 10.01 software in the control group. The CT scan and bone mineral density (BMD) measurement were performed on normal hips of the trial group, and cuboid specimens were gained from the femoral necks at the place of the tensional trabeculae to evaluate the trabecular microstructure parameters by Micro-CT, including bone volume fraction (BV/TV), trabecular number (Tb.N), trabecular spacing (Tb.Sp), trabecular thickness (Tb.Th), connect density (Conn.D), and structure model index (SMI). The correlation between imaging parameters and microstructure parameters was analyzed. In the trial group, the BMD value was 0.491-0.698 g/cm2 (mean, 0.601 g/cm2); according to World Health Organization (WHO) standard, 10 cases were diagnosed as having osteoporosis, and 6 cases as having osteopenia. The CV/MV of the trial group (0.670 1 +/- 0.102 0) was significantly lower than that of the control group (0.885 0 +/- 0.089 1) (t = -4.567, P = 0.000). In the trial group, CV/MV had correlation with BV/TV, Tb.Th, and SMI (P 0.05). BV/TV had correlation with Tb.Th, Tb.N, Tb.Sp, and SMI (P microstructure parameters (P > 0.05). CV/MV obviously decreases in the osteoporotic hip, and there is a correlation between CV/MV and the microstructure parameters of BV/TV, Tb.Th, and SMI, to some extent, which can reflect the variety of the microstructure of the trabeculae. There is no correlation between BMD of femoral neck and

  5. Effects on bone geometry, density, and microarchitecture in the distal radius but not the tibia in women with primary hyperparathyroidism

    DEFF Research Database (Denmark)

    Hansen, Stinus; Beck Jensen, Jens-Erik; Rasmussen, Lars

    2010-01-01

    Patients with primary hyperparathyroidism (PHPT) have continuously elevated parathyroid hormone (PTH) and consequently increased bone turnover with negative effects on cortical (Ct) bone with preservation of trabecular (Tb) bone. High-resolution peripheral quantitative computed tomography (HR...

  6. Bone microarchitecture and estimated bone strength in men with active acromegaly.

    Science.gov (United States)

    Silva, Paula P B; Amlashi, Fatemeh G; Yu, Elaine W; Pulaski-Liebert, Karen J; Gerweck, Anu V; Fazeli, Pouneh K; Lawson, Elizabeth; Nachtigall, Lisa B; Biller, Beverly M K; Miller, Karen K; Klibanski, Anne; Bouxsein, Mary; Tritos, Nicholas A

    2017-11-01

    Both acromegaly and adult growth hormone deficiency (GHD) are associated with increased fracture risk. Sufficient data are lacking regarding cortical bone microarchitecture and bone strength, as assessed by microfinite element analysis (µFEA). To elucidate both cortical and trabecular bone microarchitecture and estimated bone strength in men with active acromegaly or GHD compared to healthy controls. Cross-sectional study at a clinical research center, including 48 men (16 with acromegaly, 16 with GHD and 16 healthy controls). Areal bone mineral density (aBMD), cortical and trabecular bone microarchitecture and estimated bone strength (µFEA) at the radius and tibia. aBMD was not different between the 3 groups at any skeletal site. At the radius, patients with acromegaly had greater cortical area ( P  acromegaly had lower trabecular bone density ( P  = 0.0082), but no differences in cortical bone microstructure. Compressive strength and failure load did not significantly differ between groups. These findings persisted after excluding patients with hypogonadism. Bone microarchitecture was not deficient in patients with GHD. Both cortical and trabecular microarchitecture are altered in men with acromegaly. Our data indicate that GH excess is associated with distinct effects in cortical vs trabecular bone compartments. Our observations also affirm the limitations of aBMD testing in the evaluation of patients with acromegaly. © 2017 European Society of Endocrinology.

  7. Effect of epimedium pubescen flavonoid on bone mineral status and bone turnover in male rats chronically exposed to cigarette smoke.

    Science.gov (United States)

    Gao, Shu-guang; Cheng, Ling; Li, Kang-hua; Liu, Wen-He; Xu, Mai; Jiang, Wei; Wei, Li-Cheng; Zhang, Fang-jie; Xiao, Wen-feng; Xiong, Yi-lin; Tian, Jian; Zeng, Chao; Sun, Jin-peng; Xie, Qiang; Lei, Guang-hua

    2012-06-19

    Epimedii herba is one of the most frequently used herbs in formulas that are prescribed for the treatment of osteoporosis in China and its main constituent is Epimedium pubescen flavonoid (EPF). However, it is unclear whether EPF during chronic exposure to cigarette smoke may have a protective influence on the skeleton. The present study investigated the effect of EPF on bone mineral status and bone turnover in a rat model of human relatively high exposure to cigarette smoke. Fifty male Wistar rats were randomized into five groups: controls, passive smoking groups and passive smoking rats administered EPF at three dosage levels (75, 150 or 300 mg/kg/day) in drinking water for 4 months. A rat model of passive smoking was prepared by breeding male rats in a cigarette-smoking box. Bone mineral content (BMC), bone mineral density (BMD), bone turnover markers, bone histomorphometric parameters and biomechanical properties were examined. Smoke exposure decreased BMC and BMD, increased bone turnover (inhibited bone formation and stimulated its resorption), affected bone histomorphometry (increased trabecular separation and osteoclast surface per bone surface; decreased trabecular bone volume, trabecular thickness, trabecular number, cortical thickness, bone formation rate and osteoblast surface per bone surface), and reduced mechanical properties. EPF supplementation during cigarette smoke exposure prevented smoke-induced changes in bone mineral status and bone turnover. The results suggest that EPF can prevent the adverse effects of smoke exposure on bone by stimulating bone formation and inhibiting bone turnover and bone resorption.

  8. Digestibilidade ileal aparente e verdadeira de aminoácidos de farinhas de carne e ossos para suínos Apparent and true ileal digestibility of meat and bone meals amino acids for swine

    Directory of Open Access Journals (Sweden)

    Paulo Cesar Pozza

    2004-10-01

    Full Text Available O experimento foi conduzido com o objetivo de determinar a digestibilidade ileal aparente e verdadeira dos aminoácidos de seis diferentes farinhas de carne e ossos. Foram utilizados 12 suínos mestiços, machos castrados, com peso médio inicial de 52,5 ± 5,1 kg. Os animais foram previamente submetidos à cirurgia para implantação de cânula "T" simples no íleo terminal, e, após 20 dias de recuperação, foram distribuídos em um delineamento experimental de blocos ao acaso, com seis tratamentos, quatro repetições e um animal por unidade experimental. Ao término das duas primeiras repetições, os tratamentos foram redistribuídos para evitar que o mesmo animal recebesse a mesma dieta em duas repetições consecutivas. Os tratamentos consistiram de uma dieta isenta de proteína à base de açúcar, amido, óleo e casca de arroz, tendo como única fonte protéica as farinhas de carne e ossos. Os coeficientes de digestibilidade ileal aparente da lisina, treonina e metionina, das diferentes farinhas de carne e ossos variaram de 54,87 a 74,80; 62,62 a 81,19 e 72,35 a 85,46%, respectivamente, e a variação entre os coeficientes de digestibilidade ileal verdadeira foram de 57,00 a 76,08; 66,26 a 83,07 e 73,76 a 86,39%, respectivamente, para a lisina, treonina e metionina. As farinhas de carne e ossos apresentaram grande variação, em função das diferentes amostras, quanto aos coeficientes de digestibilidade ileal aparentes e verdadeiros dos aminoácidos.The experiment was carried out to determine the apparent and true ileal digestibility of amino acids from six different meat and bone meals. Twelvecrossbred swines, castrated males, averaging 52.5 ± 5.1 kg initial weight, were used. The animals were previously submitted to the simple T canula surgery implantation at the terminal ileum and, after twenty days of recovery period, they were allotted to a randomized blocks design, with six treatments, four replicates and one animal per

  9. Fisiología trabecular y glaucoma de ángulo abierto Trabecular physiology and open angle glaucoma

    Directory of Open Access Journals (Sweden)

    Yoanner Martín Perera

    2012-01-01

    Full Text Available El glaucoma constituye una de las enfermedades oculares más frecuentes en el mundo. Su etiología es variada, pero el problema radica generalmente en la evacuación del humor acuoso a nivel de la red trabecular y del canal de Schlemm. Se realizó una revisión bibliográfica sobre los principales mecanismos envueltos en la función trabecular: capacidad fagocítica de las células trabeculares, regulación de la composición de la matriz extracelular, contracción-relajación de las células trabeculares y los cambios en su volumen y forma. Un mayor conocimiento de la fisiología trabecular y su relación con la fisiopatología del glaucoma permitirá un mejor manejo de la enfermedad, así como el desarrollo de nuevos fármacos que tengan como diana la vía trabecular de manera selectiva y que permitan evitar los efectos secundarios relacionados con el empleo de medicamentos poco específicos.Glaucoma is one of the most common eye diseases worldwide, but usually the problem lies in the evacuation of aqueous humor at the trabecular meshwork and Schlemm's canal. A literature review was made about the main mechanisms involved in the trabecular function: the phagocytic capacity of trabecular cells, the regulation of the extracellular matrix composition, the contraction-relaxation of trabecular cells and the changes in their volume and shape. A better understanding of the trabecular physiology and the pathophysiology of glaucoma will allow better disease management and development of new drugs that have as their target the trabecular pathway in a selective way and that avoid the side effects associated with the use of nonspecific drugs.

  10. Relationships between bone strength and bone quality. Three-dimensional imaging analysis in ovariectomized mice

    International Nuclear Information System (INIS)

    Wakabayashi, Suguru; Sakurai, Takashi; Kashima, Isamu

    2004-01-01

    Low-energy trauma resulting in fractures of the distal femur is often observed in elderly patients with osteoporosis; such fractures are often associated with treatment difficulties and poor prognosis. The purpose of this study was to clarify the factors that affect the bone strength of the distal femur. We used ovariectomized mice to demonstrate bone quality factors associated with deterioration of the strength of the distal femur. Ten-week old ICR-strain mice were ovariectomized or sham-ovariectomized. Total bone mineral density (BMD), total bone area, cortical BMD, cortical thickness, and trabecular BMD were measured by peripheral quantitative computed tomography in the distal metaphyseal region of the femora. As three-dimensional architectural parameters, the trabecular number, trabecular thickness (Tb.Th), trabecular separation, and connectivity density were measured in the same region by micro-computed tomography. The maximum load measured by compression testing of the distal metaphyseal region was regarded as the bone strength of each sample. No significant differences in total bone area or in cortical BMD were found between the groups. Bone strength showed the closest relationship with total BMD (r=0.834). Multiple regression analysis demonstrated that total BMD greatly depended on cortical thickness. The addition of Tb.Th to trabecular BMD markedly reflected bone strength (R=0.857), suggesting that Tb.Th affected bone strength more significantly than trabecular BMD. These findings suggested that deterioration of bone strength of the distal femur (metaphysis) was not caused by a reduction in cortical BMD, but was related to reduced cortical thickness, which reduced total BMD, and to trabecular BMD and architecture, in particular to reduced Tb.Th. (author)

  11. The Role of Body Weight on Bone in Anorexia Nervosa

    DEFF Research Database (Denmark)

    Frølich, Jacob; Hansen, Stinus; Winkler, Laura Al-Dakhiel

    2017-01-01

    Anorexia nervosa (AN) is associated with decreased bone mineral density and increased risk of fracture. The aim of this study was to assess bone geometry, volumetric bone mineral density (vBMD), trabecular microarchitecture and estimated failure load in weight-bearing vs. non-weight-bearing bones...

  12. Mucopolysaccharides in the trabecular meshwork. Light and electron microscopic autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, Yoshitaka; Yamana, Yasuo; Abe, Masahiro (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine)

    1982-09-01

    The localization of /sup 35/S-sulfate and /sup 3/H-glucosamine in the trabecular region of the hamster was studied by light and electron microscopic autoradiography after the intraperitoneal injection. Exposed silver grains of /sup 35/S-sulfate were concentrated in the trabecular meshwork, sclera and cornea, and grains of /sup 35/H-glucosamine were localized in the trabecular region. The radioactivity of both isotopes was observed in the Golgi apparatuses of the endothelial cells and fibroblasts in Schlemm's canal and the trabecular meshwork. Thereafter, the grains were noted over the entire cytoplasm, except for the nucleus, and then were incorporated into the amorphous substance and collagen fibers in the juxtacanalicular connective tissue. These results suggest that endothelial cells in the trabecular region synthesize and secrete the sulfated mucopolysaccharides and hyaluronic acid.

  13. Trabecular architecture of the manual elements reflects locomotor patterns in primates.

    Science.gov (United States)

    Matarazzo, Stacey A

    2015-01-01

    The morphology of trabecular bone has proven sensitive to loading patterns in the long bones and metacarpal heads of primates. It is expected that we should also see differences in the manual digits of primates that practice different methods of locomotion. Primate proximal and middle phalanges are load-bearing elements that are held in different postures and experience different mechanical strains during suspension, quadrupedalism, and knuckle walking. Micro CT scans of the middle phalanx, proximal phalanx and the metacarpal head of the third ray were used to examine the pattern of trabecular orientation in Pan, Gorilla, Pongo, Hylobates and Macaca. Several zones, i.e., the proximal ends of both phalanges and the metacarpal heads, were capable of distinguishing between knuckle-walking, quadrupedal, and suspensory primates. Orientation and shape seem to be the primary distinguishing factors but differences in bone volume, isotropy index, and degree of anisotropy were seen across included taxa. Suspensory primates show primarily proximodistal alignment in all zones, and quadrupeds more palmar-dorsal orientation in several zones. Knuckle walkers are characterized by having proximodistal alignment in the proximal ends of the phalanges and a palmar-dorsal alignment in the distal ends and metacarpal heads. These structural differences may be used to infer locmotor propensities of extinct primate taxa.

  14. Bone densitometry in healthy cats by quantitative computed tomography; Densitometria ossea em gatos higidos por tomografia computadorizada quantitativa

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, D.C. [Universidade Federal do Parana - Curitiba, PR (Brazil); Costa, L.A.V.S.; Teixeira, M.W.; Costa, F.S. [Universidade Federal Rural de Pernambuco - Recife, PE (Brazil); Cardoso, M.J.L. [Universidade Estadual do Norte do Parana - Campus Luiz Meneghel - Bandeirantes, PR (Brazil)

    2012-06-15

    The radiodensity of the trabecular bone of the lumbar vertebrae in 16 healthy adult cats was studied using quantitative computed tomography (QCT). The average radiodensity of the trabecular bone of the second lumbar vertebra was 436.1 +- 42.1 Hounsfield units. However, there was a nonhomogeneous radiodensity distribution of the vertebral body. (author)

  15. Distribution of plutonium amongst and within selected bones from an injection case

    International Nuclear Information System (INIS)

    Larsen, R.P.; Oldham, R.D.; Martin, S.M.

    1979-01-01

    The burden and macrodistribution of plutonium in the skeleton of a man who received 0.38 μCi of 239 Pu by injection were determined. The relative concentrations in the bones analyzed are comparable to those obtained in a study of another subject. The concentrations in the trabecular and cortical portions of these bones were determined; the concentration ratio ranged from 1.9 to 4.7. The data show that (1) within a bone the plutonium concentration in the trabecular portion is always higher than it is in the cortical portion, but (2) within a group of bones plutonium concentration is not correlated with degree of trabecularity

  16. A near infrared instrument to monitor relative hemoglobin concentrations of human bone tissue in vitro and in vivo

    Science.gov (United States)

    Aziz, Syed Mahfuzul; Khambatta, Faram; Vaithianathan, Tharshan; Thomas, John C.; Clark, Jillian M.; Marshall, Ruth

    2010-04-01

    A continuous wave near infrared instrument has been developed to monitor in vivo changes in the hemoglobin concentration of the trabecular compartment of human bone. The transmitter uses only two laser diodes of wavelengths 685 and 830 nm, and the receiver uses a single silicon photodiode operating in the photovoltaic mode. The functioning of the instrument and the depth of penetration of the near infrared signals was determined in vitro using tissue-equivalent phantoms. The instrument achieves a depth of penetration of approximately 2 cm for an optode separation of 4 cm and, therefore, has the capacity to interrogate the trabecular compartment of human bone. The functioning of the instrument was tested in vivo to evaluate the relative oxy-hemoglobin (HbO2) and deoxy-hemoglobin (Hb) concentrations of the proximal tibial bone of apparently healthy, normal weight, adult subjects in response to a 3 min on, 5 min off, vascular occlusion protocol. The traces of the relative Hb and HbO2 concentrations obtained were reproducible in controlled conditions. The instrument is relatively simple and flexible, and offers an inexpensive platform for further studies to obtain normative data for healthy cohorts, and to evaluate disease-specific performance characteristics for cohorts with vasculopathies of bone.

  17. Radiographic evaluation of 19 patients with Paprosky 3A and 3B submitted to acetabular review with trabecular metal wedge

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Benvindo Rosal da Fonseca Neto

    Full Text Available ABSTRACT Objective: This study is aimed at evaluating the fixation of trabecular metal wedges in patients who underwent revision of total hip arthroplasty with large acetabular bone defects. Methods: The radiographs of 19 patients (21 hips, who underwent revision of total hip arthroplasty using trabecular metal wedges from September 2010 to December 2014 were evaluated. This study included only cases of Paprosky 3A and 3B. Preoperative and postoperative images were analyzed. Non-fixation of the implant was defined by the presence of angular variation of the component higher 10 degrees or displacement greater than 6 mm. Patients with follow-up times of less than 24 months or who did not attend the last two appointments were excluded from the study. Results: The mean follow-up time was 39.4 months (25-61. Fixation was achieved in all cases despite its complexity. There was only one case of dislocation that was treated with open reduction. One case developed infection, and was surgically approached on two occasions, with extensive debridement and intravenous antibiotics following protocol, with good evolution. Conclusion: The implanted trabecular metal wedges showed excellent results in the short- and medium-term and may represent another option in the reconstruction of large acetabular defects, sometimes replacing bone reconstruction that uses bone tissue banks or autologous graft.

  18. Bone microarchitecture and bone mineral density in multiple sclerosis

    DEFF Research Database (Denmark)

    Olsson, A; Oturai, A B; Søndergaard, H B

    2018-01-01

    BACKGROUND: Multiple sclerosis (MS) patients are at increased risk of reduced bone mineral density (BMD) and fractures. The aetiology of bone loss in MS is unclear. Trabecular bone score (TBS) is a novel analytical tool that provides a measurement of the bone microarchitecture. Decreased TBS...... included. TBS was calculated using TBS iNsight software (MediMaps® ). Multivariable regression analyses were performed with information on smoking, alcohol, glucocorticoid (GC) treatment, sun exposure, physical activity, vitamin D and BMI. RESULTS: Trabecular bone score was not significantly different from...... an age-matched reference population. Low TBS was associated with high age (P = .014) and smoking (P = .03). Smoking and physical inactivity were associated with low BMD in spine (P = .034, P = .032). GC treatment was not associated with TBS. CONCLUSION: We could not find altered TBS values among MS...

  19. Comparison of different hip prosthesis shapes considering micro-level bone remodeling and stress-shielding criteria using three-dimensional design space topology optimization.

    Science.gov (United States)

    Boyle, Christopher; Kim, Il Yong

    2011-06-03

    Since the late 1980s, computational analysis of total hip arthroplasty (THA) prosthesis components has been completed using macro-level bone remodeling algorithms. The utilization of macro-sized elements requires apparent bone densities to predict cancellous bone strength, thereby, preventing visualization and analysis of realistic trabecular architecture. In this study, we utilized a recently developed structural optimization algorithm, design space optimization (DSO), to perform a micro-level three-dimensional finite element bone remodeling simulation on the human proximal femur pre- and post-THA. The computational simulation facilitated direct performance comparison between two commercially available prosthetic implant stems from Zimmer Inc.: the Alloclassic and the Mayo conservative. The novel micro-level approach allowed the unique ability to visualize the trabecular bone adaption post-operation and to quantify the changes in bone mineral content by region. Stress-shielding and strain energy distribution were also quantified for the immediate post-operation and the stably fixated, post-remodeling conditions. Stress-shielding was highest in the proximal region and remained unchanged post-remodeling; conversely, the mid and distal portions show large increases in stress, suggesting a distal shift in the loadpath. The Mayo design conserves bone mass, while simultaneously reducing the incidence of stress-shielding compared to the Alloclassic, revealing a key benefit of the distinctive geometry. Several important factors for stable fixation, determined in clinical evaluations from the literature, were evident in both designs: high levels of proximal bone loss and distal bone densification. The results suggest this novel computational framework can be utilized for comparative hip prosthesis shape, uniquely considering the post-operation bone remodeling as a design criterion. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Mechanics of apparent horizons

    International Nuclear Information System (INIS)

    Collins, W.

    1992-01-01

    An equation for the variation in the surface area of an apparent horizon is derived which has the same form as the thermodynamic relation TdS=dQ. For a stationary vacuum black hole, the expression corresponding to a temperature equals the temperature of the event horizon. Also, if the black hole is perturbed infinitesimally by weak matter and gravitational fields, the area variation of the apparent horizon asymptotically approaches the Hartle-Hawking result for the event horizon. These results support the idea that a local version of black-hole thermodynamics in nonstationary systems can be constructed for apparent horizons

  1. Bonding strength of glass-ceramic trabecular-like coatings to ceramic substrates for prosthetic applications.

    Science.gov (United States)

    Chen, Qiang; Baino, Francesco; Pugno, Nicola M; Vitale-Brovarone, Chiara

    2013-04-01

    A new approach based on the concepts of quantized fracture mechanics (QFM) is presented and discussed in this paper to estimate the bonding strength of trabecular-like coatings, i.e. glass-ceramic scaffolds mimicking the architecture of cancellous bone, to ceramic substrates. The innovative application of glass-derived scaffolds as trabecular-like coatings is proposed in order to enhance the osteointegration of prosthetic ceramic devices. The scaffolds, prepared by polymeric sponge replication, are joined to alumina substrates by a dense glass-ceramic coating (interlayer) and the so-obtained 3-layer constructs are investigated from micro-structural, morphological and mechanical viewpoints. In particular, the fracture strengths of three different crack propagation modes, i.e. glass-derived scaffold fracture, interface delamination or mixed fracture, are predicted in agreement with those of experimental mechanical tests. The approach proposed in this work could have interesting applications towards an ever more rational design of bone tissue engineering biomaterials and coatings, in view of the optimization of their mechanical properties for making them actually suitable for clinical applications. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Crohn’s disease and Trabecular Metal implants: a report of two cases and literature review

    Directory of Open Access Journals (Sweden)

    C. Peron

    2015-10-01

    Full Text Available Aim The aim of the present study was to report two cases with Crohn’s disease in whom dental implants successfully osseointegrated and remained functionally stable up to 13 and 12 months of follow-up, respectively. Cases presentation In cases 1 (age 35 years and 2 (age 36 years, tooth 24 and 14, respectively, were atraumatically extracted and a particulated bone grafting material (buccal and palatal aspect of the defect and a Trabecular Metal implant (11.5 mm length, 4.7 mm diameter were inserted in each extraction socket. After implant placement and abutment connection with the final torque (25 Ncm, the provisional restoration was adapted in the oral cavity creating the emergence profile. The provisional crown was screw-retained and had slight occlusal contacts in the centric occlusion (intercuspation position. A periapical radiograph was taken as a control radiograph at the baseline. Postoperatively, antibiotics were prescribed as well as analgesics and an oral rinse was recommended. In both cases, the provisional restoration was removed after 2 weeks and replaced with a full ceramic restoration. Case-1 and case-2 were followed up after 13 months and 12 months respectively. In both cases postoperative healing was uneventful and radiographs taken at follow-up showed no evidence of crestal bone loss. Implants in both cases demonstrated an excellent clinical condition at follow-up. Conclusion Trabecular Metal implants can osseointegrate and remain functionally stable in patients with Crohn’s disease.

  3. Differential response of risedronate on tibial and mandibular bone quality in glucocorticoid-treated growing rats

    International Nuclear Information System (INIS)

    Fujita, Yuko

    2008-01-01

    Glucocorticoids induce bone loss and retard bone growth in children. In this study we investigated the effect of treatment with risedronate on glucocorticoid -prednisolone-induced decreases in bone density, quality, strength and growth of the tibia and mandible in growing rats. Trabecular and cortical bone structure was measured by peripheral quantitative computed tomography (pQCT) and three-dimensional (3D) micro-computed tomography (micro-CT). Indicators of bone strength were calculated from cortical bone density and the modulus of sections obtained from pQCT analysis. Tibial and mandibular bone sizes were also measured. Prednisolone decreased the bone growth of both tibia and mandible. It also caused deterioration of trabecular and cortical bone structure and strength in the mandible, and in cortical bone in the tibia, but had no effect on trabecular bone in the tibia. Risedronate inhibited the prednisolone-induced decreases in tibial width and mandibular length and height but did not improve the retardation of longitudinal bone growth. Risedronate prevented prednisolone-induced deterioration of trabecular and cortical bone architecture. In the mandible, this protective effect of risedronate was accompanied by an increase in cortical bone density and in bone strength. These findings show that risedronate inhibits prednisolone-induced loss of bone density, structure, decrease in bone strength, and retardation of bone growth in the mandible in young growing rats. (author)

  4. Bone mineral content of the forearm in healthy Dutch women

    NARCIS (Netherlands)

    Barentsen, R.; Raymakers, J.A.; Landman, J.O.; Duursma, S.A.

    1988-01-01

    Single energy photon absorptiometry is a reliable technique for assessing the bone mineral content (BMC) of cortical bone in the forearm. It can also be used for BMC measurement in the ultradistal part of the forearm, where there is a considerable proportion of trabecular bone. The results of a BMC

  5. Validation of calcaneus trabecular microstructure measurements by HR-pQCT.

    Science.gov (United States)

    Metcalf, Louis M; Dall'Ara, Enrico; Paggiosi, Margaret A; Rochester, John R; Vilayphiou, Nicolas; Kemp, Graham J; McCloskey, Eugene V

    2018-01-01

    Assessment of calcaneus microstructure using high-resolution peripheral quantitative computed tomography (HR-pQCT) might be used to improve fracture risk predictions or to assess responses to pharmacological and physical interventions. To develop a standard clinical protocol for the calcaneus, we validated calcaneus trabecular microstructure measured by HR-pQCT against 'gold-standard' micro-CT measurements. Ten human cadaveric feet were scanned in situ using HR-pQCT (isotropic 82μm voxel size) at 100, 150 and 200ms integration times, and at 100ms integration time following removal of the calcaneus from the foot (ex vivo). Dissected portions of these bones were scanned using micro-computed tomography (micro-CT) at an isotropic 17.4μm voxel size. HR-pQCT images were rigidly registered to those obtained with micro-CT and divided into multiple 5mm sided cubes to evaluate and compare morphometric parameters between the modalities. Standard HR-pQCT measurements (derived bone volume fraction (BV/TV d ); trabecular number, Tb.N; derived trabecular thickness, Tb.Th d ; derived trabecular spacing, Tb.Sp d ) and corresponding micro-CT voxel-based measurements (BV/TV, Tb.N, Tb.Th, Tb.Sp) were compared. A total of 108 regions of interest were analysed across the 10 specimens. At all integration times HR-pQCT BV/TV d was strongly correlated with micro-CT BV/TV (r 2 =0.95-0.98, RMSE=1%), but BV/TV d was systematically lower than that measured by micro-CT (mean bias=5%). In contrast, HR-pQCT systematically overestimated Tb.N at all integration times; of the in situ scans, 200ms yielded the lowest mean bias and the strongest correlation with micro-CT (r 2 =0.61, RMSE=0.15mm -1 ). Regional analysis revealed greater accuracy for Tb.N in the superior regions of the calcaneus at all integration times in situ (mean bias=0.44-0.85mm -1 ; r 2 =0.70-0.88, pmicrostructure, particularly in the superior region of the calcaneus, can be assessed by HR-pQCT. The highest integration time

  6. Bone Response to Dietary Co-Enrichment with Powdered Whole Grape and Probiotics

    Directory of Open Access Journals (Sweden)

    Cynthia Blanton

    2018-01-01

    Full Text Available Nutrition is a primary modifiable determinant of chronic noncommunicable disease, including osteoporosis. An etiology of osteoporosis is the stimulation of bone-resorbing osteoclasts by reactive oxygen species (ROS. Dietary polyphenols and probiotics demonstrate protective effects on bone that are associated with reduced ROS formation and suppressed osteoclast activity. This study tested the effect of dietary enrichment with powdered whole grape and probiotics (composed of equal parts Bifidobacterium bifidum, B. breve, Lactobacillus casei, L. plantarum, and L. bulgaricus on bone microarchitecture in a mouse model of age-related osteoporosis. Groups (n = 7 each of 10-month-old male mice were fed one of six diets for 6 months: 10% grape powder with sugar corrected to 20%; 20% grape powder; 1% probiotic with sugar corrected to 20%; 10% grape powder + 1% probiotic with sugar corrected to 20%; 20% grape powder + 1% probiotic; 20% sugar control. Femur, tibia and 4th lumbar vertebrae from 10-month-old mice served as comparator baseline samples. Bone microarchitecture was measured by micro-computed tomography and compared across diet groups using analysis of variance. Aging exerted a significant effect on tibia metaphysis trabecular bone, with baseline 10-month-old mice having significantly higher bone volume/total volume (BV/TV and trabecular number measurements and lower trabecular spacing measurements than all 16-month-old groups (p < 0.001. Neither grape nor probiotic enrichment significantly improved bone microarchitecture during aging compared to control diet. The combination of 20% grape + 1% probiotic exerted detrimental effects on tibia metaphysis BV/TV compared to 10% grape + 1% probiotic, and trabecular number and trabecular spacing compared to 10% grape + 1% probiotic, 1% probiotic and control groups (p < 0.05. Femur metaphysis trabecular bone displayed less pronounced aging effects than tibia bone, but also showed detrimental effects of the

  7. Remembering apparent behavior

    DEFF Research Database (Denmark)

    Wagoner, Brady

    2011-01-01

    The present experiment systematically investigates the role of narrative templates (Wertsch, 2002) in remembering. To stimulate the construction of a diversity of narratives I used Heider and Simmel’s (1944) celebrated “apparent behavior” film, in which geometric shapes moving around a screen...

  8. Human bone hardness seems to depend on tissue type but not on anatomical site in the long bones of an old subject.

    Science.gov (United States)

    Ohman, Caroline; Zwierzak, Iwona; Baleani, Massimiliano; Viceconti, Marco

    2013-02-01

    It has been hypothesised that among different human subjects, the bone tissue quality varies as a function of the bone segment morphology. The aim of this study was to assess and compare the quality, evaluated in terms of hardness of packages of lamellae, of cortical and trabecular bones, at different anatomical sites within the human skeleton. The contralateral six long bones of an old human subject were indented at different levels along the diaphysis and at both epiphyses of each bone. Hardness value, which is correlated to the degree of mineralisation, of both cortical and trabecular bone tissues was calculated for each indentation location. It was found that the cortical bone tissue was harder (+18%) than the trabecular one. In general, the bone hardness was found to be locally highly heterogeneous. In fact, considering one single slice obtained for a bone segment, the coefficient of variation of the hardness values was up to 12% for cortical bone and up to 17% for trabecular bone. However, the tissue hardness was on average quite homogeneous within and among the long bones of the studied donor, although differences up to 9% among levels and up to 7% among bone segments were found. These findings seem not to support the mentioned hypothesis, at least not for the long bones of an old subject.

  9. Attention and apparent motion.

    Science.gov (United States)

    Horowitz, T; Treisman, A

    1994-01-01

    Two dissociations between short- and long-range motion in visual search are reported. Previous research has shown parallel processing for short-range motion and apparently serial processing for long-range motion. This finding has been replicated and it has also been found that search for short-range targets can be impaired both by using bicontrast stimuli, and by prior adaptation to the target direction of motion. Neither factor impaired search in long-range motion displays. Adaptation actually facilitated search with long-range displays, which is attributed to response-level effects. A feature-integration account of apparent motion is proposed. In this theory, short-range motion depends on specialized motion feature detectors operating in parallel across the display, but subject to selective adaptation, whereas attention is needed to link successive elements when they appear at greater separations, or across opposite contrasts.

  10. Bone disease in primary hyperparathyroidism

    Science.gov (United States)

    Bandeira, Francisco; Cusano, Natalie E.; Silva, Barbara C.; Cassibba, Sara; Almeida, Clarissa Beatriz; Machado, Vanessa Caroline Costa; Bilezikian, John P.

    2015-01-01

    Bone disease in severe primary hyperparathyroidism (PHPT) is described classically as osteitis fibrosa cystica (OFC). Bone pain, skeletal deformities and pathological fractures are features of OFC. Bone mineral density is usually extremely low in OFC, but it is reversible after surgical cure. The signs and symptoms of severe bone disease include bone pain, pathologic fractures, proximal muscle weakness with hyperreflexia. Bone involvement is typically characterized as salt-and-pepper appearance in the skull, bone erosions and bone resorption of the phalanges, brown tumors and cysts. In the radiography, diffuse demineralization is observed, along with pathological fractures, particularly in the long bones of the extremities. In severe, symptomatic PHPT, marked elevation of the serum calcium and PTH concentrations are seen and renal involvement is manifested by nephrolithiasis and nephrocalcinosis. A new technology, recently approved for clinical use in the United States and Europe, is likely to become more widely available because it is an adaptation of the lumbar spine DXA image. Trabecular bone score (TBS) is a gray-level textural analysis that provides an indirect index of trabecular microarchitecture. Newer technologies, such as high-resolution peripheral quantitative computed tomography (HR-pQCT), have provided further understanding of the microstructural skeletal features in PHPT. PMID:25166047

  11. Effect of epimedium pubescen flavonoid on bone mineral status and bone turnover in male rats chronically exposed to cigarette smoke

    Directory of Open Access Journals (Sweden)

    Gao Shu-guang

    2012-06-01

    Full Text Available Abstract Background Epimedii herba is one of the most frequently used herbs in formulas that are prescribed for the treatment of osteoporosis in China and its main constituent is Epimedium pubescen flavonoid (EPF. However, it is unclear whether EPF during chronic exposure to cigarette smoke may have a protective influence on the skeleton. The present study investigated the effect of EPF on bone mineral status and bone turnover in a rat model of human relatively high exposure to cigarette smoke. Methods Fifty male Wistar rats were randomized into five groups: controls, passive smoking groups and passive smoking rats administered EPF at three dosage levels (75, 150 or 300 mg/kg/day in drinking water for 4 months. A rat model of passive smoking was prepared by breeding male rats in a cigarette-smoking box. Bone mineral content (BMC, bone mineral density (BMD, bone turnover markers, bone histomorphometric parameters and biomechanical properties were examined. Results Smoke exposure decreased BMC and BMD, increased bone turnover (inhibited bone formation and stimulated its resorption, affected bone histomorphometry (increased trabecular separation and osteoclast surface per bone surface; decreased trabecular bone volume, trabecular thickness, trabecular number, cortical thickness, bone formation rate and osteoblast surface per bone surface, and reduced mechanical properties. EPF supplementation during cigarette smoke exposure prevented smoke-induced changes in bone mineral status and bone turnover. Conclusion The results suggest that EPF can prevent the adverse effects of smoke exposure on bone by stimulating bone formation and inhibiting bone turnover and bone resorption.

  12. Hyperfunctioning solid/trabecular follicular carcinoma of the thyroid gland.

    Science.gov (United States)

    Giovanella, Luca; Fasolini, Fabrizio; Suriano, Sergio; Mazzucchelli, Luca

    2010-01-01

    A 68-year-old woman with solid/trabecular follicular thyroid carcinoma inside of an autonomously functioning thyroid nodule is described in this paper. The patient was referred to our clinic for swelling of the neck and an increased pulse rate. Ultrasonography showed a slightly hypoechoic nodule in the right lobe of the thyroid. Despite suppressed TSH levels, the (99m)Tc-pertechnetate scan showed a hot area corresponding to the nodule with a suppressed uptake in the remaining thyroid tissue. Histopathological examination of the nodule revealed a solid/trabecular follicular thyroid carcinoma. To the best of our knowledge, this is the first case of hyperfunctioning follicular solid/trabecular carcinoma reported in the literature. Even if a hyperfunctioning thyroid carcinoma is an extremely rare malignancy, careful management is recommended so that a malignancy will not be overlooked in the hot thyroid nodules.

  13. Hyperfunctioning Solid/Trabecular Follicular Carcinoma of the Thyroid Gland

    Directory of Open Access Journals (Sweden)

    Luca Giovanella

    2010-01-01

    Full Text Available A 68-year-old woman with solid/trabecular follicular thyroid carcinoma inside of an autonomously functioning thyroid nodule is described in this paper. The patient was referred to our clinic for swelling of the neck and an increased pulse rate. Ultrasonography showed a slightly hypoechoic nodule in the right lobe of the thyroid. Despite suppressed TSH levels, the 99mTc-pertechnetate scan showed a hot area corresponding to the nodule with a suppressed uptake in the remaining thyroid tissue. Histopathological examination of the nodule revealed a solid/trabecular follicular thyroid carcinoma. To the best of our knowledge, this is the first case of hyperfunctioning follicular solid/trabecular carcinoma reported in the literature. Even if a hyperfunctioning thyroid carcinoma is an extremely rare malignancy, careful management is recommended so that a malignancy will not be overlooked in the hot thyroid nodules.

  14. X-ray imaging characterization of femoral bones in aging mice with osteopetrotic disorder.

    Science.gov (United States)

    Tu, Shu-Ju; Huang, Hong-Wen; Chang, Wei-Jeng

    2015-04-01

    Aging mice with a rare osteopetrotic disorder in which the entire space of femoral bones are filled with trabecular bones are used as our research platform. A complete study is conducted with a micro computed tomography (CT) system to characterize the bone abnormality. Technical assessment of femoral bones includes geometric structure, biomechanical strength, bone mineral density (BMD), and bone mineral content (BMC). Normal aging mice of similar ages are included for comparisons. In our imaging work, we model the trabecular bone as a cylindrical rod and new quantitative which are not previously discussed are developed for advanced analysis, including trabecular segment length, trabecular segment radius, connecting node number, and distribution of trabecular segment radius. We then identified a geometric characteristic in which there are local maximums (0.0049, 0.0119, and 0.0147 mm) in the structure of trabecular segment radius. Our calculations show 343% higher in percent trabecular bone volume at distal-metaphysis; 38% higher in cortical thickness at mid-diaphysis; 11% higher in cortical cross-sectional moment of inertia at mid-diaphysis; 42% higher in cortical thickness at femur neck; 26% higher in cortical cross-sectional moment of inertia at femur neck; 31% and 395% higher in trabecular BMD and BMC at distal-metaphysis; 17% and 27% higher in cortical BMD and BMC at distal-metaphysis; 9% and 53% higher in cortical BMD and BMC at mid-diaphysis; 25% and 64% higher in cortical BMD and BMC at femur neck. Our new quantitative parameters and findings may be extended to evaluate the treatment response for other similar bone disorders. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    DEFF Research Database (Denmark)

    Ulhøi, Maiken Parm; Meldgaard, Karoline; Steiniche, Torben

    2017-01-01

    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...

  16. Autologous implantation of BMP2-expressing dermal fibroblasts to improve bone mineral density and architecture in rabbit long bones.

    Science.gov (United States)

    Ishihara, Akikazu; Weisbrode, Steve E; Bertone, Alicia L

    2015-10-01

    Cell-mediated gene therapy may treat bone fragility disorders. Dermal fibroblasts (DFb) may be an alternative cell source to stem cells for orthopedic gene therapy because of their rapid cell yield and excellent plasticity with bone morphogenetic protein-2 (BMP2) gene transduction. Autologous DFb or BMP2-expressing autologous DFb were administered in twelve rabbits by two delivery routes; a transcortical intra-medullar infusion into tibiae and delayed intra-osseous injection into femoral drill defects. Both delivery methods of DFb-BMP2 resulted in a successful cell engraftment, increased bone volume, bone mineral density, improved trabecular bone microarchitecture, greater bone defect filling, external callus formation, and trabecular surface area, compared to non-transduced DFb or no cells. Cell engraftment within trabecular bone and bone marrow tissue was most efficiently achieved by intra-osseous injection of DFb-BMP2. Our results suggested that BMP2-expressing autologous DFb have enhanced efficiency of engraftment in target bones resulting in a measurable biologic response by the bone of improved bone mineral density and bone microarchitecture. These results support that autologous implantation of DFb-BMP2 warrants further study on animal models of bone fragility disorders, such as osteogenesis imperfecta and osteoporosis to potentially enhance bone quality, particularly along with other gene modification of these diseases. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  17. Mechanical Loading Attenuates Radiation-Induced Bone Loss in Bone Marrow Transplanted Mice

    Science.gov (United States)

    Govey, Peter M.; Zhang, Yue; Donahue, Henry J.

    2016-01-01

    Exposure of bone to ionizing radiation, as occurs during radiotherapy for some localized malignancies and blood or bone marrow cancers, as well as during space travel, incites dose-dependent bone morbidity and increased fracture risk. Rapid trabecular and endosteal bone loss reflects acutely increased osteoclastic resorption as well as decreased bone formation due to depletion of osteoprogenitors. Because of this dysregulation of bone turnover, bone’s capacity to respond to a mechanical loading stimulus in the aftermath of irradiation is unknown. We employed a mouse model of total body irradiation and bone marrow transplantation simulating treatment of hematologic cancers, hypothesizing that compression loading would attenuate bone loss. Furthermore, we hypothesized that loading would upregulate donor cell presence in loaded tibias due to increased engraftment and proliferation. We lethally irradiated 16 female C57Bl/6J mice at age 16 wks with 10.75 Gy, then IV-injected 20 million GFP(+) total bone marrow cells. That same day, we initiated 3 wks compression loading (1200 cycles 5x/wk, 10 N) in the right tibia of 10 of these mice while 6 mice were irradiated, non-mechanically-loaded controls. As anticipated, before-and-after microCT scans demonstrated loss of trabecular bone (-48.2% Tb.BV/TV) and cortical thickness (-8.3%) at 3 wks following irradiation. However, loaded bones lost 31% less Tb.BV/TV and 8% less cortical thickness (both pbones also had significant increases in trabecular thickness and tissue mineral densities from baseline. Mechanical loading did not affect donor cell engraftment. Importantly, these results demonstrate that both cortical and trabecular bone exposed to high-dose therapeutic radiation remain capable of an anabolic response to mechanical loading. These findings inform our management of bone health in cases of radiation exposure. PMID:27936104

  18. Biomechanical study of the bone tissue with dental implants interaction

    Directory of Open Access Journals (Sweden)

    Navrátil P.

    2011-12-01

    Full Text Available The article deals with the stress-strain analysis of human mandible in the physiological state and after the dental implant application. The evaluation is focused on assessing of the cancellous bone tissue modeling-level. Three cancellous bone model-types are assessed: Non-trabecular model with homogenous isotropic material, nontrabecular model with inhomogeneous material obtained from computer tomography data using CT Data Analysis software, and trabecular model built from mandible section image. Computational modeling was chosen as the most suitable solution method and the solution on two-dimensional level was carried out. The results show that strain is more preferable value than stress in case of evaluation of mechanical response in cancellous bone. The non-trabecular model with CT-obtained material model is not acceptable for stress-strain analysis of the cancellous bone for singularities occurring on interfaces of regions with different values of modulus of elasticity.

  19. Dietary Pseudopurpurin Improves Bone Geometry Architecture and Metabolism in Red-Bone Guishan Goats

    Science.gov (United States)

    Han, TieSuo; Li, Peng; Wang, JianGuo; Liu, GuoWen; Wang, Zhe; Ge, ChangRong; Gao, ShiZheng

    2012-01-01

    Red-colored bones were found initially in some Guishan goats in the 1980s, and they were designated red-boned goats. However, it is not understood what causes the red color in the bone, or whether the red material changes the bone geometry, architecture, and metabolism of red-boned goats. Pseudopurpurin was identified in the red-colored material of the bone in red-boned goats by high-performance liquid chromatography–electrospray ionization–mass spetrometry and nuclear magnetic resonance analysis. Pseudopurpurin is one of the main constituents of Rubia cordifolia L, which is eaten by the goats. The assessment of the mechanical properties and micro-computed tomography showed that the red-boned goats displayed an increase in the trabecular volume fraction, trabecular thickness, and the number of trabeculae in the distal femur. The mean thickness, inner perimeter, outer perimeter, and area of the femoral diaphysis were also increased. In addition, the trabecular separation and structure model index of the distal femur were decreased, but the bone mineral density of the whole femur and the mechanical properties of the femoral diaphysis were enhanced in the red-boned goats. Meanwhile, expression of alkaline phosphatase and osteocalcin mRNA was higher, and the ratio of the receptor activator of the nuclear factor kappa B ligand to osteoprotegerin was markedly lower in the bone marrow of the red-boned goats compared with common goats. To confirm further the effect of pseudopurpurin on bone geometry, architecture, and metabolism, Wistar rats were fed diets to which pseudopurpurin was added for 5 months. Similar changes were observed in the femurs of the treated rats. The above results demonstrate that pseudopurpurin has a close affinity with the mineral salts of bone, and consequently a high level of mineral salts in the bone cause an improvement in bone strength and an enhancement in the structure and metabolic functions of the bone. PMID:22624037

  20. Determination of bone mineral density in the third lumbar vertebral body using photon absorptiometry techniques

    International Nuclear Information System (INIS)

    Swanpalmer, Janos; Kullenberg, Ragnar; Hansson, Tommy

    1998-01-01

    Dual-photon absorptiometry and triple-energy X-ray absorptiometry were used to investigate the total bone mineral content and density as well as the trabecular bone mineral density in the third lumbar vertebral body. Both anteroposterior (AP) and lateral (LAT) measurements were performed. By combining the two projections it was found that the mean trabecular bone mineral density for all 202 subjects included in the study was 52% (SD±20%) of the total bone mineral density in the third lumbar vertebral body. The mean trabecular bone mineral density as a fraction of the total vertebral body bone mineral density decreased as a function of age. The relative annual change in this fraction differed between males and females. It was also found that neither trabecular nor total bone mineral density differed significantly between male and female subjects aged 25-35 years, and bone mineral density (BMD), expressed in g/cm 3 , showed no correlation to subject height, body weight or body mass index (BMI). Male and female individuals showed different rates of change of trabecular bone mineral density with age

  1. Monocyte chemotactic protein-1 deficiency attenuates and high-fat diet exacerbates bone loss in mice with Lewis lung carcinoma.

    Science.gov (United States)

    Yan, Lin; Nielsen, Forrest H; Sundaram, Sneha; Cao, Jay

    2017-04-04

    Bone loss occurs in obesity and cancer-associated complications including wasting. This study determined whether a high-fat diet and a deficiency in monocyte chemotactic protein-1 (MCP-1) altered bone structural defects in male C57BL/6 mice with Lewis lung carcinoma (LLC) metastases in lungs. Compared to non-tumor-bearing mice, LLC reduced bone volume fraction, connectivity density, trabecular number, trabecular thickness and bone mineral density and increased trabecular separation in femurs. Similar changes occurred in vertebrae. The high-fat diet compared to the AIN93G diet exacerbated LLC-induced detrimental structural changes; the exacerbation was greater in femurs than in vertebrae. Mice deficient in MCP-1 compared to wild-type mice exhibited increases in bone volume fraction, connectivity density, trabecular number and decreases in trabecular separation in both femurs and vertebrae, and increases in trabecular thickness and bone mineral density and a decrease in structure model index in vertebrae. Lewis lung carcinoma significantly decreased osteocalcin but increased tartrate-resistant acid phosphatase 5b (TRAP 5b) in plasma. In LLC-bearing mice, the high-fat diet increased and MCP-1 deficiency decreased plasma TRAP 5b; neither the high-fat diet nor MCP-1 deficiency resulted in significant changes in plasma concentration of osteocalcin. In conclusion, pulmonary metastasis of LLC is accompanied by detrimental bone structural changes; MCP-1 deficiency attenuates and high-fat diet exacerbates the metastasis-associated bone wasting.

  2. Changes of enzyme activities in lens after glaucoma trabecular resection

    Directory of Open Access Journals (Sweden)

    Jian-Ping Wang

    2013-08-01

    Full Text Available AIM: To observe the change of lens antioxidant enzyme activity after glaucoma trabecular resection. METHODS: Thirty-two eyes of sixteen New-Zealand rabbits(2.2-2.4kgwere divided into two groups. The left eyes of rabbits underwent standard glaucoma trabecular resection were treatment group, and the normal right eyes served as controls. Transparency of lenses was monitored by a slit-lamp biomicroscopy before and after glaucoma trabecular resection. The morphology of lens cells was observed under the light microscope.The activities of Na+-K+-ATPase,catalase(CAT, glutathion peroxidase(GSH-px, glutathione reductase(GR, superoxide dismutase(SODand content of malondialdehyde(MDAin lenses were detected six months after trabecular resection. RESULTS: Lenses were clear in both treatment group and normal control group during the six months after operation. The morphology and structure of lens cells were normal under the light microscope in both operation group and normal group. The activity of lens cells antioxidant enzyme activity were significantly decreased in operation group compared with control group, Na+-K+-ATPase declined by 20.97%, CAT declined by 16.36%, SOD declined by 4.46%, GR declined by 4.85%, GSH-px declined by 10.02%, and MDA increased by 16.31%. CONCLUSION: Glaucoma trabecular resection can induce the change of Na+-K+-ATPase, CAT, GSH-px, GR, SOD and MDA in lens of rabbit. Glaucoma filtration surgery for the occurrence of cataract development mechanism has important guiding significance.

  3. Augmented mandibular bone structurally adapts to functional loading

    NARCIS (Netherlands)

    Verhoeven, J. W.; Ruijter, J. M.; Koole, R.; de Putter, C.; Terlou, M.; Cune, M. S.

    2013-01-01

    Long-term changes in trabecular bone structure during the 10 years following onlay grafting with simultaneous mandibular implant placement were studied. Extraoral radiographs of both mandibular sides in eight patients were taken regularly. Bone structure was analysed using a custom-written image

  4. Analysis of the of bones through 3D computerized tomography

    International Nuclear Information System (INIS)

    Lima, I.; Lopes, R.T.; Oliveira, L.F.; Alves, J.M.

    2009-01-01

    This work shows the analysis of the internal structure of the bones samples through 3D micro tomography technique (3D-μTC). The comprehension of the bone structure is particularly important when related to osteoporosis diagnosis because this implies in a deterioration of the trabecular bone architecture, which increases the fragility and the possibility to have bone fractures. Two bone samples (human calcaneous and Wistar rat femur) were used, and the method was a radiographic system in real time with an X Ray microfocus tube. The quantifications parameters are based on stereological principles and they are five: a bone volume fraction, trabecular number, the ratio between surface and bone volume, the trabecular thickness and the trabecular separation. The quantifications were done with a program developed especially for this purpose in Nuclear Instrumentation Laboratory - COPPE/UFRJ. This program uses as input the 3D reconstructions images and generates a table with the quantifications. The results of the human calcaneous quantifications are presented in tables 1 and 2, and the 3D reconstructions are illustrated in Figure 5. The Figure 6 illustrate the 2D reconstructed image and the Figure 7 the 3D visualization respectively of the Wistar femur sample. The obtained results show that the 3D-μTC is a powerful technique that can be used to analyze bone microstructures. (author)

  5. Biglycan deficiency interferes with ovariectomy-induced bone loss

    DEFF Research Database (Denmark)

    Nielsen, Karina L; Allen, Matthew R; Bloomfield, Susan A

    2003-01-01

    Biglycan is a matrix proteoglycan with a possible role in bone turnover. In a 4-week study with sham-operated or OVX biglycan-deficient or wildtype mice, we show that biglycan-deficient mice are resistant to OVX-induced trabecular bone loss and that there is a gender difference in the response...

  6. The behavior of adaptive bone-remodeling simulation models

    NARCIS (Netherlands)

    H.H. Weinans (Harrie); R. Huiskes (Rik); H.J. Grootenboer

    1992-01-01

    textabstractThe process of adaptive bone remodeling can be described mathematically and simulated in a computer model, integrated with the finite element method. In the model discussed here, cortical and trabecular bone are described as continuous materials with variable density. The remodeling rule

  7. Exposure to Low-Dose X-Ray Radiation Alters Bone Progenitor Cells and Bone Microarchitecture.

    Science.gov (United States)

    Lima, Florence; Swift, Joshua M; Greene, Elisabeth S; Allen, Matthew R; Cunningham, David A; Braby, Leslie A; Bloomfield, Susan A

    2017-10-01

    Exposure to high-dose ionizing radiation during medical treatment exerts well-documented deleterious effects on bone health, reducing bone density and contributing to bone growth retardation in young patients and spontaneous fracture in postmenopausal women. However, the majority of human radiation exposures occur in a much lower dose range than that used in the radiation oncology clinic. Furthermore, very few studies have examined the effects of low-dose ionizing radiation on bone integrity and results have been inconsistent. In this study, mice were irradiated with a total-body dose of 0.17, 0.5 or 1 Gy to quantify the early (day 3 postirradiation) and delayed (day 21 postirradiation) effects of radiation on bone microarchitecture and bone marrow stromal cells (BMSCs). Female BALBc mice (4 months old) were divided into four groups: irradiated (0.17, 0.5 and 1 Gy) and sham-irradiated controls (0 Gy). Micro-computed tomography analysis of distal femur trabecular bone from animals at day 21 after exposure to 1 Gy of X-ray radiation revealed a 21% smaller bone volume (BV/TV), 22% decrease in trabecular numbers (Tb.N) and 9% greater trabecular separation (Tb.Sp) compared to sham-irradiated controls (P X-rays, whereas osteoclastogenesis was enhanced. A better understanding of the effects of radiation on osteoprogenitor cell populations could lead to more effective therapeutic interventions that protect bone integrity for individuals exposed to low-dose ionizing radiation.

  8. Cement stress predictions after anatomic total shoulder arthroplasty are correlated with preoperative glenoid bone quality.

    Science.gov (United States)

    Terrier, Alexandre; Obrist, Raphaël; Becce, Fabio; Farron, Alain

    2017-09-01

    We hypothesized that biomechanical parameters typically associated with glenoid implant failure after anatomic total shoulder arthroplasty (aTSA) would be correlated with preoperative glenoid bone quality. We developed an objective automated method to quantify preoperative glenoid bone quality in different volumes of interest (VOIs): cortical bone, subchondral cortical plate, subchondral bone after reaming, subchondral trabecular bone, and successive layers of trabecular bone. Average computed tomography (CT) numbers (in Hounsfield units [HU]) were measured in each VOI from preoperative CT scans. In parallel, we built patient-specific finite element models of simulated aTSAs to predict cement stress, bone-cement interfacial stress, and bone strain around the glenoid implant. CT measurements and finite element predictions were obtained for 20 patients undergoing aTSA for primary glenohumeral osteoarthritis. We tested all linear correlations between preoperative patient characteristics (age, sex, height, weight, glenoid bone quality) and biomechanical predictions (cement stress, bone-cement interfacial stress, bone strain). Average CT numbers gradually decreased from cortical (717 HU) to subchondral and trabecular (362 HU) bone. Peak cement stress (4-10 MPa) was located within the keel hole, above the keel, or behind the glenoid implant backside. Cement stress, bone-cement interfacial stress, and bone strain were strongly negatively correlated with preoperative glenoid bone quality, particularly in VOIs behind the implant backside (subchondral trabecular bone) but also in deeper trabecular VOIs. Our numerical study suggests that preoperative glenoid bone quality is an important parameter to consider in aTSA, which may be associated with aseptic loosening of the glenoid implant. These initial results should now be confronted with clinical and radiologic outcomes. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc

  9. Dual-photon absorptiometry: A new method of determining bone mineral content. Pt. 1

    International Nuclear Information System (INIS)

    Buttermann, G.; Eiber, J.; Hennig, J.; Pabst, H.W.

    1988-01-01

    Cortical (neck of femur) and trabecular (L 2-4) bone mass has been determined repeatedly with DPA using 153 Gd (NOVO Lab 22 a) in 545 females and 112 males with no evidence of bone diseases. Measured 'normal' (age- and sex-related average) values for bone mineral content (BMC) differed significantly (p [de

  10. Use of a biomimetic strategy to engineer bone.

    Science.gov (United States)

    Holy, C E; Fialkov, J A; Davies, J E; Shoichet, M S

    2003-06-15

    Engineering trabecular-like, three-dimensional bone tissue throughout biodegradable polymer scaffolds is a significant challenge. Using a novel processing technique, we have created a biodegradable scaffold with geometry similar to that of trabecular bone. When seeded with bone-marrow cells, new bone tissue, the geometry of which reflected that of the scaffold, was evident throughout the scaffold volume and to a depth of 10 mm. Preseeded scaffolds implanted in non-healing rabbit segmental bone defects allowed new functional bone formation and bony union to be achieved throughout the defects within 8 weeks. This marks the first report of successful three-dimensional bone-tissue engineering repair using autologous marrow cells without the use of supplementary growth factors. We attribute our success to the novel scaffold morphology. Copyright 2003 Wiley Periodicals, Inc. J Biomed Mater Res 65A: 447-453, 2003

  11. Receptor tyrosine kinase inhibition causes simultaneous bone loss and excess bone formation within growing bone in rats

    International Nuclear Information System (INIS)

    Nurmio, Mirja; Joki, Henna; Kallio, Jenny; Maeaettae, Jorma A.; Vaeaenaenen, H. Kalervo; Toppari, Jorma; Jahnukainen, Kirsi; Laitala-Leinonen, Tiina

    2011-01-01

    During postnatal skeletal growth, adaptation to mechanical loading leads to cellular activities at the growth plate. It has recently become evident that bone forming and bone resorbing cells are affected by the receptor tyrosine kinase (RTK) inhibitor imatinib mesylate (STI571, Gleevec (registered) ). Imatinib targets PDGF, ABL-related gene, c-Abl, c-Kit and c-Fms receptors, many of which have multiple functions in the bone microenvironment. We therefore studied the effects of imatinib in growing bone. Young rats were exposed to imatinib (150 mg/kg on postnatal days 5-7, or 100 mg/kg on postnatal days 5-13), and the effects of RTK inhibition on bone physiology were studied after 8 and 70 days (3-day treatment), or after 14 days (9-day treatment). X-ray imaging, computer tomography, histomorphometry, RNA analysis and immunohistochemistry were used to evaluate bone modeling and remodeling in vivo. Imatinib treatment eliminated osteoclasts from the metaphyseal osteochondral junction at 8 and 14 days. This led to a resorption arrest at the growth plate, but also increased bone apposition by osteoblasts, thus resulting in local osteopetrosis at the osteochondral junction. The impaired bone remodelation observed on day 8 remained significant until adulthood. Within the same bone, increased osteoclast activity, leading to bone loss, was observed at distal bone trabeculae on days 8 and 14. Peripheral quantitative computer tomography (pQCT) and micro-CT analysis confirmed that, at the osteochondral junction, imatinib shifted the balance from bone resorption towards bone formation, thereby altering bone modeling. At distal trabecular bone, in turn, the balance was turned towards bone resorption, leading to bone loss. - Research highlights: → 3-Day imatinib treatment. → Causes growth plate anomalies in young rats. → Causes biomechanical changes and significant bone loss at distal trabecular bone. → Results in loss of osteoclasts at osteochondral junction.

  12. New insights to the role of aryl hydrocarbon receptor in bone phenotype and in dioxin-induced modulation of bone microarchitecture and material properties

    International Nuclear Information System (INIS)

    Herlin, Maria; Finnilä, Mikko A.J.; Zioupos, Peter; Aula, Antti; Risteli, Juha; Miettinen, Hanna M.; Jämsä, Timo; Tuukkanen, Juha; Korkalainen, Merja; Håkansson, Helen; Viluksela, Matti

    2013-01-01

    Bone is a target for high affinity aryl hydrocarbon receptor (AHR) ligands, such as dioxins. Although bone morphology, mineral density and strength are sensitive endpoints of dioxin toxicity, less is known about effects on bone microarchitecture and material properties. This study characterizes TCDD-induced modulations of bone tissue, and the role of AHR in dioxin-induced bone toxicity and for normal bone phenotype. Six AHR-knockout (Ahr −/− ) and wild-type (Ahr +/+ ) mice of both genders were exposed to TCDD weekly for 10 weeks, at a total dose of 200 μg/kg bw. Bones were examined with micro-computed tomography, nanoindentation and biomechanical testing. Serum levels of bone remodeling markers were analyzed, and the expression of genes related to osteogenic differentiation was profiled using PCR array. In Ahr +/+ mice, TCDD-exposure resulted in harder bone matrix, thinner and more porous cortical bone, and a more compact trabecular bone compartment. Bone remodeling markers and altered expression of a number of osteogenesis related genes indicated imbalanced bone remodeling. Untreated Ahr −/− mice displayed a slightly modified bone phenotype as compared with untreated Ahr +/+ mice, while TCDD exposure caused only a few changes in bones of Ahr −/− mice. Part of the effects of both TCDD-exposure and AHR-deficiency were gender dependent. In conclusion, exposure of adult mice to TCDD resulted in harder bone matrix, thinner cortical bone, mechanically weaker bones and most notably, increased trabecular bone volume fraction in Ahr +/+ mice. AHR is involved in bone development of a normal bone phenotype, and is crucial for manifestation of TCDD-induced bone alterations. - Highlights: • TCDD disrupts bone remodeling resulting in altered cortical and trabecular bone. • In trabecular bone an anabolic effect is observed. • Cortical bone is thinner, more porous, harder, stiffer and mechanically weaker. • AHR ablation results in increased trabecular bone

  13. New insights to the role of aryl hydrocarbon receptor in bone phenotype and in dioxin-induced modulation of bone microarchitecture and material properties

    Energy Technology Data Exchange (ETDEWEB)

    Herlin, Maria, E-mail: maria.herlin@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Finnilä, Mikko A.J., E-mail: mikko.finnila@oulu.fi [Department of Medical Technology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Department of Anatomy and Cell Biology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Zioupos, Peter, E-mail: p.zioupos@cranfield.ac.uk [Biomechanics Laboratories, Department of Engineering and Applied Science, Cranfield University, Shrivenham SN6 8LA (United Kingdom); Aula, Antti, E-mail: antti.aula@gmail.com [Department of Medical Physics, Imaging Centre, Tampere University Hospital, Tampere (Finland); Department of Biomedical Engineering, Tampere University of Technology, Tampere (Finland); Risteli, Juha, E-mail: juha.risteli@ppshp.fi [Department of Clinical Chemistry, Oulu University Hospital, Oulu (Finland); Miettinen, Hanna M., E-mail: hanna.miettinen@crl.com [Department of Environmental Health, National Institute for Health and Welfare, Kuopio (Finland); Jämsä, Timo, E-mail: timo.jamsa@oulu.fi [Department of Medical Technology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Department of Diagnostic Radiology, Oulu University Hospital, Oulu (Finland); Tuukkanen, Juha, E-mail: juha.tuukkanen@oulu.fi [Department of Anatomy and Cell Biology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Korkalainen, Merja, E-mail: merja.korkalainen@thl.fi [Department of Environmental Health, National Institute for Health and Welfare, Kuopio (Finland); Håkansson, Helen, E-mail: Helen.Hakansson@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Viluksela, Matti, E-mail: matti.viluksela@thl.fi [Department of Environmental Health, National Institute for Health and Welfare, Kuopio (Finland); Department of Environmental Science, University of Eastern Finland, Kuopio (Finland)

    2013-11-15

    Bone is a target for high affinity aryl hydrocarbon receptor (AHR) ligands, such as dioxins. Although bone morphology, mineral density and strength are sensitive endpoints of dioxin toxicity, less is known about effects on bone microarchitecture and material properties. This study characterizes TCDD-induced modulations of bone tissue, and the role of AHR in dioxin-induced bone toxicity and for normal bone phenotype. Six AHR-knockout (Ahr{sup −/−}) and wild-type (Ahr{sup +/+}) mice of both genders were exposed to TCDD weekly for 10 weeks, at a total dose of 200 μg/kg bw. Bones were examined with micro-computed tomography, nanoindentation and biomechanical testing. Serum levels of bone remodeling markers were analyzed, and the expression of genes related to osteogenic differentiation was profiled using PCR array. In Ahr{sup +/+} mice, TCDD-exposure resulted in harder bone matrix, thinner and more porous cortical bone, and a more compact trabecular bone compartment. Bone remodeling markers and altered expression of a number of osteogenesis related genes indicated imbalanced bone remodeling. Untreated Ahr{sup −/−} mice displayed a slightly modified bone phenotype as compared with untreated Ahr{sup +/+} mice, while TCDD exposure caused only a few changes in bones of Ahr{sup −/−} mice. Part of the effects of both TCDD-exposure and AHR-deficiency were gender dependent. In conclusion, exposure of adult mice to TCDD resulted in harder bone matrix, thinner cortical bone, mechanically weaker bones and most notably, increased trabecular bone volume fraction in Ahr{sup +/+} mice. AHR is involved in bone development of a normal bone phenotype, and is crucial for manifestation of TCDD-induced bone alterations. - Highlights: • TCDD disrupts bone remodeling resulting in altered cortical and trabecular bone. • In trabecular bone an anabolic effect is observed. • Cortical bone is thinner, more porous, harder, stiffer and mechanically weaker. • AHR ablation

  14. Piroxicam treatment augments bone abnormalities in interleukin-10 knockout mice.

    Science.gov (United States)

    Holgersen, Kristine; Dobie, Ross; Farquharson, Colin; vanʼt Hof, Rob; Ahmed, Syed Faisal; Hansen, Axel Kornerup; Holm, Thomas L

    2015-02-01

    Osteoporosis and fractures are common complications of inflammatory bowel disease. The pathogenesis is multifactorial and has been partly attributed to intestinal inflammation. The aim of this study was to evaluate bone status and assess the association between bone loss and gut inflammation in an experimental colitis model. Colitis was induced in interleukin-10 knockout mice (PAC IL-10 k.o.) by peroral administration of piroxicam for 12 days. The degree of colitis was assessed by clinical, macroscopic, and microscopic evaluation. Trabecular and cortical bone microarchitecture of tibia were determined using micro-computed tomography. Moreover, the serum levels of bone formation and bone resorption biomarkers were measured, and inflammatory protein profiling was performed on colons. PAC IL-10 k.o. mice developed severe colitis, characterized by hyperplasia and focal transmural inflammation, which was consistent with Crohn's disease-like pathology. The gut inflammation was accompanied by a 14% and 12% reduction in trabecular thickness relative to piroxicam-treated wild type and untreated wild type mice, respectively (P < 0.001). The trabecular bone structure was also changed in PAC IL-10 k.o. mice, whereas no differences in cortical bone geometry were observed. The trabecular thickness was inversely correlated with serum levels of CTX (r = -0.93, P = 0.006). Moreover, numerous inflammatory mediators, including RANKL and osteoprotegerin, were significantly increased in the colon of PAC IL-10 k.o. mice. PAC IL-10 k.o. mice develop bone loss and changed trabecular structure, as a result of increased bone resorption. Thus, the PAC IL-10 k.o. model could be a useful experimental model in preclinical research of inflammatory bowel disease-associated bone loss.

  15. Engineering bone grafts with enhanced bone marrow and native scaffolds.

    Science.gov (United States)

    Hung, Ben P; Salter, Erin K; Temple, Josh; Mundinger, Gerhard S; Brown, Emile N; Brazio, Philip; Rodriguez, Eduardo D; Grayson, Warren L

    2013-01-01

    The translation of tissue engineering approaches to the clinic has been hampered by the inability to find suitable multipotent cell sources requiring minimal in vitro expansion. Enhanced bone marrow (eBM), which is obtained by reaming long bone medullary canals and isolating the solid marrow putty, has large quantities of stem cells and demonstrates significant potential to regenerate bone tissues. eBM, however, cannot impart immediate load-bearing mechanical integrity or maintain the gross anatomical structure to guide bone healing. Yet, its putty-like consistency creates a challenge for obtaining the uniform seeding necessary to effectively combine it with porous scaffolds. In this study, we examined the potential for combining eBM with mechanically strong, osteoinductive trabecular bone scaffolds for bone regeneration by creating channels into scaffolds for seeding the eBM. eBM was extracted from the femurs of adult Yorkshire pigs using a Synthes reamer-irrigator-aspirator device, analyzed histologically, and digested to extract cells and characterize their differentiation potential. To evaluate bone tissue formation, eBM was seeded into the channels in collagen-coated or noncoated scaffolds, cultured in osteogenic conditions for 4 weeks, harvested and assessed for tissue distribution and bone formation. Our data demonstrates that eBM is a heterogenous tissue containing multipotent cell populations. Furthermore, coating scaffolds with a collagen hydrogel significantly enhanced cellular migration, promoted uniform tissue development and increased bone mineral deposition. These findings suggest the potential for generating customized autologous bone grafts for treating critical-sized bone defects by combining a readily available eBM cell source with decellularized trabecular bone scaffolds. © 2013 S. Karger AG, Basel

  16. Mechanical Modelling of Cancellous Bone from their Microstructure

    Directory of Open Access Journals (Sweden)

    Ruiz–Cervantes O.

    2010-04-01

    Full Text Available In this paper is established a spongy bone bidimensional models methodology for its analysis by finite element software. The models are focused to represent the bone trabecular structure by Voronoi cells, using the coordinates of the porous center, contained within the bone structure, obtained by optical microscope images. Looking for a better geometrical similarity, it was assigned a thicker transversal area in the trabecula union zone, because has been reported that this factor gives a better approximation to experimental results. To feed the finite element models, compression test has been done to trabecular specimens, taking the maximum strain and maximum stress, to obtain the elastic modulus. By means of strained specimen images analysis, it has been established the structure collapse moment. It was when the 36% of total trabeculae failed. Finally it was obtained a tissue Young modulus of 323 [MPa] and with this value, the resistance variation in function of density and trabecular architecture.

  17. Human trabecular meshwork cells express BMP antagonist mRNAs and proteins.

    Science.gov (United States)

    Tovar-Vidales, Tara; Fitzgerald, Ashley M; Clark, Abbot F

    2016-06-01

    Glaucoma patients have elevated aqueous humor and trabecular meshwork (TM) levels of transforming growth factor-beta2 (TGF-β2). TGF-β2 has been associated with increased extracellular matrix (ECM) deposition (i.e. fibronectin), which is attributed to the increased resistance of aqueous humor outflow through the TM. We have previously demonstrated that bone morphogenetic protein (BMP) 4 selectively counteracts the profibrotic effect of TGF-β2 with respect to ECM synthesis in the TM, and this action is reversed by the BMP antagonist gremlin. Thus, the BMP and TGF-β signaling pathways antagonize each other's antifibrotic and profibrotic roles. The purpose of this study was to determine whether cultured human TM cells: (a) express other BMP antagonists including noggin, chordin, BMPER, BAMBI, Smurf1 and 2, and (b) whether expression of these proteins is regulated by exogenous TGF-β2 treatment. Primary human trabecular meshwork (TM) cells were grown to confluency and treated with TGF-β2 (5 ng/ml) for 24 or 48 h in serum-free medium. Untreated cell served as controls. qPCR and Western immunoblots (WB) determined that human TM cells expressed mRNAs and proteins for the BMP antagonist proteins: noggin, chordin, BMPER, BAMBI, and Smurf1/2. Exogenous TGF-β2 decreased chordin, BMPER, BAMBI, and Smurf1 mRNA and protein expression. In contrast, TGF-β2 increased secreted noggin and Smurf2 mRNA and protein levels. BMP antagonist members are expressed in the human TM. These molecules may be involved in the normal function of the TM as well as TM pathogenesis. Altered expression of BMP antagonist members may lead to functional changes in the human TM. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Evaluating two-dimensional skeletal structure parameters using radiological bone morphometric analysis

    International Nuclear Information System (INIS)

    Asa, Kensuke; Sakurai, Takashi; Kashima, Isamu; Kumasaka, Satsuki

    2005-01-01

    The objectives of this study was to investigate the reliability of two-dimensional (2D) skeletal structure parameters obtained using radiological bone morphometric analysis. The 2D skeletal parameters in the regions of interest (ROIs) were measured on computed radiography (CR) images of first phalanges from racehorses, using radiological bone morphometric analysis. Cancellous bone blocks were made from the phalanges in the same position as the ROI determined on CR images. Three-dimensional (3D) trabecular parameters were measured using micro-computed tomography (μCT). The correlations between the 2D skeletal parameters and 3D trabecular parameters were evaluated in relation to the measured bone strength. The following 2D skeletal structure parameters were correlated with bone strength (r=0.61-0.69): skeletal perimeter (Sk.Pm), skeletal number (Sk.N), skeletal separation (Sk.Sp), skeletal spacing (Sk.Spac), fractal dimension (FD), and skeletal pattern factor (SkPf). The 3D trabecular structure parameters were closely correlated with bone strength (r=0.74-0.86). The 2D skeletal parameters Sk.N, Sk.Pm, FD, SkPf, and Sk.Spac were correlated with the 3D trabecular parameters (r=0.61-0.70). The 2D skeletal parameters obtained using radiological bone morphometric analysis may be useful indicators of trabecular strength. (author)

  19. Kinetic examination of femoral bone modeling in broilers.

    Science.gov (United States)

    Prisby, R; Menezes, T; Campbell, J; Benson, T; Samraj, E; Pevzner, I; Wideman, R F

    2014-05-01

    Lameness in broilers can be associated with progressive degeneration of the femoral head leading to femoral head necrosis and osteomyelitis. Femora from clinically healthy broilers were dissected at 7 (n = 35, 2), 14 (n = 32), 21 (n = 33), 28 (n = 34), and 42 (n = 28) d of age, and were processed for bone histomorphometry to examine bone microarchitecture and bone static and dynamic properties in the secondary spongiosa (IISP) of the proximal femoral metaphysis. Body mass increased rapidly with age, whereas the bone volume to tissue volume ratio remained relatively consistent. The bone volume to tissue volume ratio values generally reflected corresponding values for both mean trabecular thickness and mean trabecular number. Bone metabolism was highest on d 7 when significant osteoblast activity was reflected by increased osteoid surface to bone surface and mineralizing surface per bone surface ratios. However, significant declines in osteoblast activity and bone formative processes occurred during the second week of development, such that newly formed but unmineralized bone tissue (osteoid) and the percentages of mineralizing surfaces both were diminished. Osteoclast activity was elevated to the extent that measurement was impossible. Intense osteoclast activity presumably reflects marked bone resorption throughout the experiment. The overall mature trabecular bone volume remained relatively low, which may arise from extensive persistence of chondrocyte columns in the metaphysis, large areas in the metaphysis composed of immature bone, destruction of bone tissue in the primary spongiosa, and potentially reduced bone blood vessel penetration that normally would be necessary for robust development. Delayed bone development in the IISP was attributable to an uncoupling of osteoblast and osteoclast activity, whereby bone resorption (osteoclast activity) outpaced bone formation (osteoblast activity). Insufficient maturation and mineralization of the IISP may contribute

  20. Advances in imaging: impact on studying craniofacial bone structure.

    Science.gov (United States)

    Majumdar, S

    2003-01-01

    Methods for measuring the structure of craniofacial bones are discussed in this paper. In addition to the three-dimensional macro-structure of the craniofacial skeleton, there is considerable interest in imaging the bone at a microscopic resolution in order to depict the micro-architecture of the trabecular bone itself. In addition to the density of the bone, the microarchitecture reflects bone quality. An understanding of bone quality and density changes has implications for a number of craniofacial pathologies, as well as for implant design and understanding the biomechanical function and loading of the jaw. Trabecular bone micro-architecture has been recently imaged using imaging methods such as micro-computed tomography, magnetic resonance imaging, and the images have been used in finite element models to assess bone mechanical properties. In this paper, some of the recent advances in micro-computed tomography and magnetic resonance imaging are reviewed, and their potential for imaging the trabecular bone in mandibular bones is presented. Examples of in vitro and in vivo images are presented.

  1. High-resolution-cone beam tomography analysis of bone microarchitecture in patients with acromegaly and radiological vertebral fractures.

    Science.gov (United States)

    Maffezzoni, Filippo; Maddalo, Michele; Frara, Stefano; Mezzone, Monica; Zorza, Ivan; Baruffaldi, Fabio; Doglietto, Francesco; Mazziotti, Gherardo; Maroldi, Roberto; Giustina, Andrea

    2016-11-01

    Vertebral fractures are an emerging complication of acromegaly but their prediction is still difficult occurring even in patients with normal bone mineral density. In this study we evaluated the ability of high-resolution cone-beam computed tomography to provide information on skeletal abnormalities associated with vertebral fractures in acromegaly. 40 patients (24 females, 16 males; median age 57 years, range 25-72) and 21 healthy volunteers (10 females, 11 males; median age 60 years, range: 25-68) were evaluated for trabecular (bone volume/trabecular volume ratio, mean trabecular separation, and mean trabecular thickness) and cortical (thickness and porosity) parameters at distal radius using a high-resolution cone-beam computed tomography system. All acromegaly patients were evaluated for morphometric vertebral fractures and for mineral bone density by dual-energy X-ray absorptiometry at lumbar spine, total hip, femoral neck, and distal radius. Acromegaly patients with vertebral fractures (15 cases) had significantly (p acromegaly patients did not have significant differences in bone density at either skeletal site. Patients with acromegaly showed lower bone volume/trabecular volume ratio (p = 0.003) and mean trabecular thickness (p acromegaly. High-resolution cone-beam computed tomography at the distal radius may be useful to evaluate and predict the effects of acromegaly on bone microstructure.

  2. Bone loss in long-term suppressive therapy with thyroid hormone

    International Nuclear Information System (INIS)

    Firooznia, H.; Blum, M.; Golimbu, C.; Rafii, M.

    1987-01-01

    The trabecular bone density of the spine was measured with CT in 31 women, aged 39-79 years, who had received an average of 13.5 years of thyroid suppressive therapy. The spinal trabecular bone density values in 24 (77%), 18 (58%), and 13 subjects (42%) were respectively below the mean for healthy age-matched controls, the fifth percentile for healthy premenopausal women, and the fifth percentile for age-matched controls. Cortical and trabecular bone loss occurs in hyperthyroidism. Although the intent is not to cause hyperthyroidism in subjects on suppressive therapy, supraphysical doses of thyroid hormone are usually necessary for suppression of thyroid-stimulating hormone. In this study, bone loss was noted in these subjects. Because most of these patients are middle-aged or postmenopausal women, who are at risk for osteoporosis, it is important to be aware of the risk of additional bone loss induced by thyroid suppressive therapy in them

  3. The importance of zinc on osteoporotic bones

    Energy Technology Data Exchange (ETDEWEB)

    Lima, I.; Lopes, R.T. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Engenharia Nuclear]. E-mail: ricardo@lin.ufrj.br; inaya@lin.ufrj.br; Anjos, M.J. [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Inst. de Fisica]. E-mail: marcelin@lin.ufrj.br; Farias, M.L.F. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Hospital Universitario. Servico de Endocrinologia]. E-mail: fleiuss@hucff.ufrj.br; Rosenthal, D. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Biofisica Carlos Chagas Filho. Lab. de Fisiologia Endocrina]. E-mail: doris@biof.ufrj.br

    2007-07-01

    Zinc is an essential element that can be found in bones, such as calcium and phosphorus. It seems to have effects on growth, bone turnover and mineralization making its relationship with bones still opening. The goal of this study is, by XRF analysis, characterized bone samples, with and without pathology, in the trabecular region. For that purpose, it was used an XRF beam line at the Synchrotron Light National Laboratory (Campinas, Brazil). The results show that the profile of the zinc distribution and its concentration on femoral heads are strongly related to the associated pathology. (author)

  4. The importance of zinc on osteoporotic bones

    International Nuclear Information System (INIS)

    Lima, I.; Lopes, R.T.; Anjos, M.J.; Farias, M.L.F.; Rosenthal, D.

    2007-01-01

    Zinc is an essential element that can be found in bones, such as calcium and phosphorus. It seems to have effects on growth, bone turnover and mineralization making its relationship with bones still opening. The goal of this study is, by XRF analysis, characterized bone samples, with and without pathology, in the trabecular region. For that purpose, it was used an XRF beam line at the Synchrotron Light National Laboratory (Campinas, Brazil). The results show that the profile of the zinc distribution and its concentration on femoral heads are strongly related to the associated pathology. (author)

  5. Skeletal unloading induces selective resistance to the anabolic actions of growth hormone on bone

    Science.gov (United States)

    Halloran, B. P.; Bikle, D. D.; Harris, J.; Autry, C. P.; Currier, P. A.; Tanner, S.; Patterson-Buckendahl, P.; Morey-Holton, E.

    1995-01-01

    Loss of skeletal weight bearing or physical unloading of bone in the growing animal inhibits bone formation and induces a bone mineral deficit. To determine whether the inhibition of bone formation induced by skeletal unloading in the growing animal is a consequence of diminished sensitivity to growth hormone (GH) we studied the effects of skeletal unloading in young hypophysectomized rats treated with GH (0, 50, 500 micrograms/100 g body weight/day). Skeletal unloading reduced serum osteocalcin, impaired uptake of 3H-proline into bone, decreased proximal tibial mass, and diminished periosteal bone formation at the tibiofibular junction. When compared with animals receiving excipient alone, GH administration increased bone mass in all animals. The responses in serum osteocalcin, uptake of 3H-proline and 45Ca into the proximal tibia, and proximal tibial mass in non-weight bearing animals were equal to those in weight bearing animals. The responses in trabecular bone volume in the proximal tibia and bone formation at the tibiofibular junction to GH, however, were reduced significantly by skeletal unloading. Bone unloading prevented completely the increase in metaphyseal trabecular bone normally induced by GH and severely dampened the stimulatory effect (158% vs. 313%, p < 0.002) of GH on periosteal bone formation. These results suggest that while GH can stimulate the overall accumulation of bone mineral in both weight bearing and non-weight bearing animals, skeletal unloading selectively impairs the response of trabecular bone and periosteal bone formation to the anabolic actions of GH.

  6. Skeletal unloading induces selective resistance to the anabolic actions of growth hormone on bone

    Science.gov (United States)

    Halloran, B. P.; Bikle, D. D.; Harris, J.; Autry, C. P.; Currier, P. A.; Tanner, S.; Patterson-Buckendahl, P.; Morey-Holton, E.

    1995-01-01

    Loss of skeletal weight bearing or physical unloading of bone in the growing animal inhibits bone formation and induces a bone mineral deficit. To determine whether the inhibition of bone formation induced by skeletal unloading in the growing animal is a consequence of diminished sensitivity to growth hormone (GH) we studied the effects of skeletal unloading in young hypophysectomized rats treated with GH (0, 50, 500 micrograms/100 g body weight/day). Skeletal unloading reduced serum osteocalcin, impaired uptake of 3H-proline into bone, decreased proximal tibial mass, and diminished periosteal bone formation at the tibiofibular junction. When compared with animals receiving excipient alone, GH administration increased bone mass in all animals. The responses in serum osteocalcin, uptake of 3H-proline and 45Ca into the proximal tibia, and proximal tibial mass in non-weight bearing animals were equal to those in weight bearing animals. The responses in trabecular bone volume in the proximal tibia and bone formation at the tibiofibular junction to GH, however, were reduced significantly by skeletal unloading. Bone unloading prevented completely the increase in metaphyseal trabecular bone normally induced by GH and severely dampened the stimulatory effect (158% vs. 313%, p bone formation. These results suggest that while GH can stimulate the overall accumulation of bone mineral in both weight bearing and non-weight bearing animals, skeletal unloading selectively impairs the response of trabecular bone and periosteal bone formation to the anabolic actions of GH.

  7. Limited Associations between Keel Bone Damage and Bone Properties Measured with Computer Tomography, Three-Point Bending Test, and Analysis of Minerals in Swiss Laying Hens

    Directory of Open Access Journals (Sweden)

    Sabine G. Gebhardt-Henrich

    2017-08-01

    Full Text Available Keel bone damage is a wide-spread welfare problem in laying hens. It is unclear so far whether bone quality relates to keel bone damage. The goal of the present study was to detect possible associations between keel bone damage and bone properties of intact and damaged keel bones and of tibias in end-of-lay hens raised in loose housing systems. Bones were palpated and examined by peripheral quantitative computer tomography (PQCT, a three-point bending test, and analyses of bone ash. Contrary to our expectations, PQCT revealed higher cortical and trabecular contents in fractured than in intact keel bones. This might be due to structural bone repair after fractures. Density measurements of cortical and trabecular tissues of keel bones did not differ between individuals with and without fractures. In the three-point bending test of the tibias, ultimate shear strength was significantly higher in birds with intact vs. fractured keel bones. Likewise, birds with intact or slightly deviated keel bones had higher mineral and calcium contents of the keel bone than birds with fractured keel bones. Calcium content in keel bones was correlated with calcium content in tibias. Although there were some associations between bone traits related to bone strength and keel bone damage, other factors such as stochastic events related to housing such as falls and collisions seem to be at least as important for the prevalence of keel bone damage.

  8. Scintigraphic findings of bone and bone-marrow and determination of bone mineral density using photon absorptiometry in osteopetrosis

    International Nuclear Information System (INIS)

    Otsuka, Nobuaki; Fukunaga, Masao; Morita, Koichi

    1988-01-01

    On a 15-year-old girl with osteopetrosis, bone and bonemarrow scintigraphy were performed. Also, bone mineral density (BMD) with quantitative CT (QCT), single photon absorptiometry (SPA) and dual photon absorptiometry (DPA) were measured. On bone scintigraphy the diffusely increased skeletal uptake and relatively diminished renal uptake were noted. On the other hand, on bone marrow scintigraphy poor accumulation in central marrow and peripheral expansion were shown. BMD value by QCT and DPA (mainly trabecular bone) was markedly high, while BMD by SPA (mainly cortical bone) was within normal range. Thus, it was shown that bone and bone-marrow scintigraphy combined with BMD measurement by photon absorptiometry were useful and essential in evaluating the pathophysiology of osteosclerosis. (author)

  9. Three-dimensional microarchitecture of adolescent cancellous bone

    DEFF Research Database (Denmark)

    Ding, Ming; Danielsen, Carl Christian; Hvid, Ivan

    2012-01-01

    , the adolescent cancellous bone had similar bone volume fraction (BV/TV), structure type (plate, rod or mixtures), and connectivity (3-D trabecular networks) as the adult cancellous bone. The adolescent cancellous bone had significantly lower bone surface density (bone surface per total volume of specimen...... and lateral condyle. These samples were micro-CT scanned (vivaCT 40, Scanco Medical AG, Switzerland) resulting in cubic voxel sizes of 10.5⁎10.5⁎10.5μm(3). Microarchitectural properties were calculated. The samples were then tested in compression followed by collagen and mineral determination. Interestingly...

  10. Scanning electron microscopy of the trabecular meshwork: Understanding the pathogenesis of primary angle closure glaucoma

    Directory of Open Access Journals (Sweden)

    Ramanjit Sihota

    2012-01-01

    Full Text Available Purpose: To study ultrastructural changes of the trabecular meshwork in acute and chronic primary angle closure glaucoma (PACG and primary open angle glaucoma (POAG eyes by scanning electron microscopy. Materials and Methods: Twenty-one trabecular meshwork surgical specimens from consecutive glaucomatous eyes after a trabeculectomy and five postmortem corneoscleral specimens were fixed immediately in Karnovsky solution. The tissues were washed in 0.1 M phosphate buffer saline, post-fixed in 1% osmium tetraoxide, dehydrated in acetone series (30-100%, dried and mounted. Results: Normal trabecular tissue showed well-defined, thin, cylindrical uveal trabecular beams with many large spaces, overlying flatter corneoscleral beams and numerous smaller spaces. In acute PACG eyes, the trabecular meshwork showed grossly swollen, irregular trabecular endothelial cells with intercellular and occasional basal separation with few spaces. Numerous activated macrophages, leucocytes and amorphous debris were present. Chronic PACG eyes had a few, thickened posterior uveal trabecular beams visible. A homogenous deposit covered the anterior uveal trabeculae and spaces. Converging, fan-shaped trabecular beam configuration corresponded to gonioscopic areas of peripheral anterior synechiae. In POAG eyes, anterior uveal trabecular beams were thin and strap-like, while those posteriorly were wide, with a homogenous deposit covering and bridging intertrabecular spaces, especially posteriorly. Underlying corneoscleral trabecular layers and spaces were visualized in some areas. Conclusions: In acute PACG a marked edema of the endothelium probably contributes for the acute and marked intraocular pressure (IOP elevation. Chronically raised IOP in chronic PACG and POAG probably results, at least in part, from decreased aqueous outflow secondary to widening and fusion of adjacent trabecular beams, together with the homogenous deposit enmeshing trabecular beams and spaces.

  11. Microstructural Assessment of Cancellous Bone Using 3D Microtomography

    International Nuclear Information System (INIS)

    Silva A M H; Alves J M; Da Silva O L; Silva Junior N F; Gazziro M; Pereira J C; Lasso P R O; Vaz C M P; Pereira C A M; Leiva T P; Guarniero R

    2011-01-01

    Cancellous bones have a porous microstructure and can be modeled as linear elastic solid, heterogeneous and anisotropic. Few studies regarding the morphometric analysis of trabecular bone samples with 3D microtomography have been published so far. The technique has spread worldwide for the characterization of trabecular structures in studies related to bone quality and its relationship with metabolic diseases bone like osteoporosis. In our study cancellous bone samples with cubic and cylindrical geometry were extracted from bovine femur were used to investigate the structural arrangement of bone through high resolution x-ray 3D microtomography (μCT). Four trabecular microstructural parameters (tissue volume, bone volume, bone volume fraction and tissue surface) were measured by 2D (stereological method) and 3D morphometric analysis using the software CTan Analyser supplied by the manufacturer of the microtomograph (SkyScan, model 1172, Belgium). The measurements were done in three main directions (superior-inferior, medial-lateral and anterior-posterior) to investigate the correlation between the 2D and 3D morphometric analysis. The results show a high correlation between the analysis. The x-ray 3D microtomography technique has a great potential for the assessment of bone quality.

  12. The bisphosphonate zoledronate prevents vertebral bone loss in mature estrogen-deficient rats as assessed by micro-computed tomography

    Directory of Open Access Journals (Sweden)

    Glatt M.

    2001-01-01

    Full Text Available The effect of long-term treatment with the bisphosphonate zoledronate on vertebral bone architecture was investigated in estrogen-deficient mature rats. 4-month-old rats were ovariectomized and development of cancellous osteopenia was assessed after 1 year. The change of bone architectural parameters was determined with a microtomographic instrument of high resolution. After 1 year of estrogen-deficiency, animals lost 55% of vertebral trabecular bone in comparison to sham operated control animals. Trabecular number (Tb.N and trabecular thickness (Tb.Th were significantly reduced in ovariectomized animals, whereas trabecular separation (Tb.Sp, bone surface to volume fraction (BS/BV and trabecular bone pattern factor (TBPf were significantly increased, indicating a loss of architectural integrity throughout the vertebral body. 3 groups of animals were treated subcutaneously with zoledronate for 1 year with 0.3, 1.5 and 7.5 microgram/kg/week to inhibit osteoclastic bone degradation. Administration started immediately after ovariectomy and treatment dose-dependently prevented the architectural bone deterioration and completely suppressed the effects of estrogen deficiency at the higher doses. The results show that microtomographic determination of static morphometric parameters can be used to quantitate the effects of drugs on vertebral bone architecture in small laboratory animals and that zoledronate is highly effective in this rat model.

  13. Bone Density, Microarchitecture, and Tissue Quality Long-term After Kidney Transplant.

    Science.gov (United States)

    Pérez-Sáez, María José; Herrera, Sabina; Prieto-Alhambra, Daniel; Nogués, Xavier; Vera, María; Redondo-Pachón, Dolores; Mir, Marisa; Güerri, Roberto; Crespo, Marta; Díez-Pérez, Adolfo; Pascual, Julio

    2017-06-01

    Bone mineral density (BMD) measured by dual-energy x-ray absorptiometry is used to assess bone health in kidney transplant recipients (KTR). Trabecular bone score and in vivo microindentation are novel techniques that directly measure trabecular microarchitecture and mechanical properties of bone at a tissue level and independently predict fracture risk. We tested the bone status of long-term KTR using all 3 techniques. Cross-sectional study including 40 KTR with more than 10 years of follow-up and 94 healthy nontransplanted subjects as controls. Bone mineral density was measured at lumbar spine and the hip. Trabecular bone score was measured by specific software on the dual-energy x-ray absorptiometry scans of lumbar spine in 39 KTR and 77 controls. Microindentation was performed at the anterior tibial face with a reference-point indenter device. Bone measurements were standardized as percentage of a reference value, expressed as bone material strength index (BMSi) units. Multivariable (age, sex, and body mass index-adjusted) linear regression models were fitted to study the association between KTR and BMD/BMSi/trabecular bone score. Bone mineral density was lower at lumbar spine (0.925 ± 0.15 vs 0.982 ± 0.14; P = 0.025), total hip (0.792 ± 0.14 vs 0.902 ± 0.13; P bone score was borderline lower (1.21 ± 0.14 vs 1.3 ± 0.15; adjusted P = 0.072) in KTR. Despite persistent decrease in BMD, trabecular microarchitecture and tissue quality remain normal in long-term KTR, suggesting important recovery of bone health.

  14. Trabecular metal acetabular components in primary total hip arthroplasty

    DEFF Research Database (Denmark)

    Laaksonen, Inari; Lorimer, Michelle; Gromov, Kirill

    2018-01-01

    Background and purpose - Trabecular metal (TM) cups have demonstrated favorable results in acetabular revision and their use in primary total hip arthroplasty (THA) is increasing. Some evidence show that TM cups might decrease periprosthetic infection (PPI) incidence. We compared the survivorship...... of TM cups with that of other uncemented cups in primary THA, and evaluated whether the use of TM cups is associated with a lower risk of PPI. Patients and methods - 10,113 primary THAs with TM cup and 85,596 THAs with other uncemented cups from 2 high-quality national arthroplasty registries were...

  15. Hyperfunctioning Solid/Trabecular Follicular Carcinoma of the Thyroid Gland

    OpenAIRE

    Luca Giovanella; Fabrizio Fasolini; Sergio Suriano; Luca Mazzucchelli

    2010-01-01

    A 68-year-old woman with solid/trabecular follicular thyroid carcinoma inside of an autonomously functioning thyroid nodule is described in this paper. The patient was referred to our clinic for swelling of the neck and an increased pulse rate. Ultrasonography showed a slightly hypoechoic nodule in the right lobe of the thyroid. Despite suppressed TSH levels, the 9 9 m T c -pertechnetate scan showed a hot area corresponding to the nodule with a suppressed uptake in the remaining thyroid tissu...

  16. Comparative analysis of bone mineral contents with dual-energy quantitative computed tomography

    International Nuclear Information System (INIS)

    Choi, T. J.; Yoon, S. M.; Kim, O. B.; Lee, S. M.; Suh, S. J.

    1997-01-01

    The Dual-Energy Quantitative Computed Tomography(DEQCT) was compared with bone equivalent K 2 HPO 4 standard solution and ash weight of animal cadaveric trabecular bone in the measurement of bone mineral contents(BMC). The attenuation coefficient of tissues highly depends on the radiation energy, density and effective atomic number of composition. The bone mineral content of DEQCT in this experiments was determined from empirical constants and mass attenuation coefficients of bone, fat and soft tissue equivalent solution in two photon spectra. In this experiments, the BMC of DEQCT with 80 and 120kV p X rays was compared to ash weight of animal trabecular bone. We obtained the mass attenuation coefficient of 0.2409, 0.5608 and 0.2206 in 80kV p , and 0.2046, 0.3273 and 0.1971 cm 2 /g in 120kV p X-ray spectra for water, bone and fat equivalent materials, respectively. The BMC with DEQCT was accomplished with empirical constants K 1 =0.3232, K 2 =0.2450 and mass attenuation coefficients has very closed to ash weight of animal trabecular bone. The BMC of empirical DEQCT and that of manufacturing DEQCT were correlated with ash weight as a correlation r=0.998 and r=0.996, respectively. The BMC of empirical DEQCT using the experimental mass attenuation coefficients and that of manufacture have showed very close to ash weight of animal trabecular bone. (author)

  17. Chronic central administration of Ghrelin increases bone mass through a mechanism independent of appetite regulation.

    Directory of Open Access Journals (Sweden)

    Hyung Jin Choi

    Full Text Available Leptin plays a critical role in the central regulation of bone mass. Ghrelin counteracts leptin. In this study, we investigated the effect of chronic intracerebroventricular administration of ghrelin on bone mass in Sprague-Dawley rats (1.5 μg/day for 21 days. Rats were divided into control, ghrelin ad libitum-fed (ghrelin ad lib-fed, and ghrelin pair-fed groups. Ghrelin intracerebroventricular infusion significantly increased body weight in ghrelin ad lib-fed rats but not in ghrelin pair-fed rats, as compared with control rats. Chronic intracerebroventricular ghrelin infusion significantly increased bone mass in the ghrelin pair-fed group compared with control as indicated by increased bone volume percentage, trabecular thickness, trabecular number and volumetric bone mineral density in tibia trabecular bone. There was no significant difference in trabecular bone mass between the control group and the ghrelin ad-lib fed group. Chronic intracerebroventricular ghrelin infusion significantly increased the mineral apposition rate in the ghrelin pair-fed group as compared with control. In conclusion, chronic central administration of ghrelin increases bone mass through a mechanism that is independent of body weight, suggesting that ghrelin may have a bone anabolic effect through the central nervous system.

  18. Sex Steroid Actions in Male Bone

    Science.gov (United States)

    Laurent, Michaël R.; Claessens, Frank; Gielen, Evelien; Lagerquist, Marie K.; Vandenput, Liesbeth; Börjesson, Anna E.; Ohlsson, Claes

    2014-01-01

    Sex steroids are chief regulators of gender differences in the skeleton, and male gender is one of the strongest protective factors against osteoporotic fractures. This advantage in bone strength relies mainly on greater cortical bone expansion during pubertal peak bone mass acquisition and superior skeletal maintenance during aging. During both these phases, estrogens acting via estrogen receptor-α in osteoblast lineage cells are crucial for male cortical and trabecular bone, as evident from conditional genetic mouse models, epidemiological studies, rare genetic conditions, genome-wide meta-analyses, and recent interventional trials. Genetic mouse models have also demonstrated a direct role for androgens independent of aromatization on trabecular bone via the androgen receptor in osteoblasts and osteocytes, although the target cell for their key effects on periosteal bone formation remains elusive. Low serum estradiol predicts incident fractures, but the highest risk occurs in men with additionally low T and high SHBG. Still, the possible clinical utility of serum sex steroids for fracture prediction is unknown. It is likely that sex steroid actions on male bone metabolism rely also on extraskeletal mechanisms and cross talk with other signaling pathways. We propose that estrogens influence fracture risk in aging men via direct effects on bone, whereas androgens exert an additional antifracture effect mainly via extraskeletal parameters such as muscle mass and propensity to fall. Given the demographic trends of increased longevity and consequent rise of osteoporosis, an increased understanding of how sex steroids influence male bone health remains a high research priority. PMID:25202834

  19. [Bone Cell Biology Assessed by Microscopic Approach. A mathematical approach to understand bone remodeling].

    Science.gov (United States)

    Kameo, Yoshitaka; Adachi, Taiji

    2015-10-01

    It is well known that bone tissue can change its outer shape and internal structure by remodeling according to a changing mechanical environment. However, the mechanism of bone functional adaptation induced by the collaborative metabolic activities of bone cells in response to mechanical stimuli remains elusive. In this article, we focus on the hierarchy of bone structure and function from the microscopic cellular level to the macroscopic tissue level. We provide an overview of a mathematical approach to understand the adaptive changes in trabecular morphology under the application of mechanical stress.

  20. Is cortical bone hip? What determines cortical bone properties?

    Science.gov (United States)

    Epstein, Sol

    2007-07-01

    Increased bone turnover may produce a disturbance in bone structure which may result in fracture. In cortical bone, both reduction in turnover and increase in hip bone mineral density (BMD) may be necessary to decrease hip fracture risk and may require relatively greater proportionate changes than for trabecular bone. It should also be noted that increased porosity produces disproportionate reduction in bone strength, and studies have shown that increased cortical porosity and decreased cortical thickness are associated with hip fracture. Continued studies for determining the causes of bone strength and deterioration show distinct promise. Osteocyte viability has been observed to be an indicator of bone strength, with viability as the result of maintaining physiological levels of loading and osteocyte apoptosis as the result of a decrease in loading. Osteocyte apoptosis and decrease are major factors in the bone loss and fracture associated with aging. Both the osteocyte and periosteal cell layer are assuming greater importance in the process of maintaining skeletal integrity as our knowledge of these cells expand, as well being a target for pharmacological agents to reduce fracture especially in cortical bone. The bisphosphonate alendronate has been seen to have a positive effect on cortical bone by allowing customary periosteal growth, while reducing the rate of endocortical bone remodeling and slowing bone loss from the endocortical surface. Risedronate treatment effects were attributed to decrease in bone resorption and thus a decrease in fracture risk. Ibandronate has been seen to increase BMD as the spine and femur as well as a reduced incidence of new vertebral fractures and non vertebral on subset post hoc analysis. And treatment with the anabolic agent PTH(1-34) documented modeling and remodelling of quiescent and active bone surfaces. Receptor activator of nuclear factor kappa B ligand (RANKL) plays a key role in bone destruction, and the human monoclonal

  1. Suppressor of cytokine signaling 2 (Socs2 deletion protects bone health of mice with DSS-induced inflammatory bowel disease

    Directory of Open Access Journals (Sweden)

    Ross Dobie

    2018-01-01

    Full Text Available Individuals with inflammatory bowel disease (IBD often present with poor bone health. The development of targeted therapies for this bone loss requires a fuller understanding of the underlying cellular mechanisms. Although bone loss in IBD is multifactorial, the altered sensitivity and secretion of growth hormone (GH and insulin-like growth factor-1 (IGF-1 in IBD is understood to be a critical contributing mechanism. The expression of suppressor of cytokine signaling 2 (SOCS2, a well-established negative regulator of GH signaling, is stimulated by proinflammatory cytokines. Therefore, it is likely that SOCS2 expression represents a critical mediator through which proinflammatory cytokines inhibit GH/IGF-1 signaling and decrease bone quality in IBD. Using the dextran sodium sulfate (DSS model of colitis, we reveal that endogenously elevated GH function in the Socs2−/− mouse protects the skeleton from osteopenia. Micro-computed tomography assessment of DSS-treated wild-type (WT mice revealed a worsened trabecular architecture compared to control mice. Specifically, DSS-treated WT mice had significantly decreased bone volume, trabecular thickness and trabecular number, and a resulting increase in trabecular separation. In comparison, the trabecular bone of Socs2-deficient mice was partially protected from the adverse effects of DSS. The reduction in a number of parameters, including bone volume, was less, and no changes were observed in trabecular thickness or separation. This protected phenotype was unlikely to be a consequence of improved mucosal health in the DSS-treated Socs2−/− mice but rather a result of unregulated GH signaling directly on bone. These studies indicate that the absence of SOCS2 is protective against bone loss typical of IBD. This study also provides an improved understanding of the relative effects of GH/IGF-1 signaling on bone health in experimental colitis, information that is essential before these drugs are

  2. Bone histomorphometry in de novo renal transplant recipients indicates a further decline in bone resorption 1 year posttransplantation.

    Science.gov (United States)

    Evenepoel, Pieter; Behets, Geert J; Viaene, Liesbeth; D'Haese, Patrick C

    2017-02-01

    Renal transplantation is believed to have a major impact on bone health. The present prospective observational bone biopsy study aimed to define the natural history of bone histomorphometry parameters in contemporaneous de novo renal transplant recipients. Paired bone biopsies were performed at the time of transplantation and at one-year posttransplantation in an unselected cohort of 36 patients referred for deceased kidney replacement. Parameters of mineral metabolism and circulating bone turnover markers were monitored as well. Static parameters of bone formation and especially bone resorption being already low-normal in the majority of patients at the time of renal transplantation, further declined during the first posttransplant year. However, interindividual variation was substantial, and significance was reached only for bone resorption parameters. Bone mineralization and trabecular bone volume were within the normal range at the time of transplantation (83.3% and 91.7% of graft recipients, respectively) and showed little change one-year posttransplantation. Changes in osteoclast number were paralleled by changes in circulating tartrate-resistant acid phosphatase 5b levels. Finally, cumulative glucocorticoid dose, but not the posttransplantation parathyroid hormone level, associated with trabecular bone loss. Thus, the impact of renal transplantation on bone histomorphometry is limited with only bone resorption, being already low at the time of transplantation, showing a further decline. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  3. Infill Optimization for Additive Manufacturing - Approaching Bone-like Porous Structures

    DEFF Research Database (Denmark)

    Wu, Jun; Aage, Niels; Westermann, Ruediger

    2018-01-01

    Porous structures such as trabecular bone are widely seen in nature. These structures exhibit superior mechanical properties whilst being lightweight. In this paper, we present a method to generate bone-like porous structures asl ightweight infill for additive manufacturing. Our method builds upon...

  4. The Anabolic Effect of PTH on Bone is Attenuated by Simultaneous Glucocorticoid Treatment

    DEFF Research Database (Denmark)

    Oxlund, Hans; Ørtoft, Gitte; Thomsen, Jesper Skovhus

    2006-01-01

    . The pronounced anabolic effect of PTH injections on the endocortical and trabecular bone surfaces and less pronounced anabolic effect on periosteal surfaces were partially inhibited, but not prevented, by simultaneous GC treatment in old rats. Both cortical and cancellous bone possessed full mechanical...

  5. Contrast Agents for Micro-Computed Tomography of Microdamage in Bone

    National Research Council Canada - National Science Library

    Roeder, Ryan K

    2008-01-01

    ...) and contrast agents with higher x-ray attenuation than bone. The ability to detect the presence and to a limited extent the morphology of microdamage in cortical and trabecular bone using micro-CT was demonstrated using a barium sulfate (BaSO4) stain...

  6. Trabecular meshwork ECM remodeling in glaucoma: could RAS be a target?

    Science.gov (United States)

    Agarwal, Puneet; Agarwal, Renu

    2018-06-14

    Disturbances of extracellular matrix (ECM) homeostasis in trabecular meshwork (TM) cause increased aqueous outflow resistance leading to elevated intraocular pressure (IOP) in glaucomatous eyes. Therefore, restoration of ECM homeostasis is a rational approach to prevent disease progression. Since renin-angiotensin system (RAS) inhibition positively alters ECM homeostasis in cardiovascular pathologies involving pressure and volume overload, it is likely that RAS inhibitors reduce IOP primarily by restoring ECM homeostasis. Areas covered: Current evidence showing the presence of RAS components in ocular tissue and its role in regulating aqueous humor dynamics is briefly summarized. The role of RAS in ECM remodeling is discussed both in terms of its effects on ECM synthesis and its breakdown. The mechanisms of ECM remodeling involving interactions of RAS with transforming growth factor-β, Wnt/β-catenin signaling, bone morphogenic proteins, connective tissue growth factor, and matrix metalloproteinases in ocular tissue are discussed. Expert opinion: Current literature strongly indicates a significant role of RAS in ECM remodeling in TM of hypertensive eyes. Hence, IOP-lowering effect of RAS inhibitors may primarily be attributed to restoration of ECM homeostasis in aqueous outflow pathways rather than its vascular effects. However, the mechanistic targets for RAS inhibitors have much wider distribution and consequences, which remain relatively unexplored in TM.

  7. Simulation of ultrasound propagation in bone

    Science.gov (United States)

    Kaufman, Jonathan J.; Luo, Gangming; Siffert, Robert S.

    2004-10-01

    Ultrasound has been proposed as a means to noninvasively assess bone and, particularly, bone strength and fracture risk, as for example in osteoporosis. Because strength is a function of both mineral density and architecture, ultrasound has the potential to provide more accurate measurement of bone integrity than, for example, with x-ray absorptiometric methods. Although some of this potential has already been realized-a number of clinical devices are presently available-there is still much that is unknown regarding the interaction of ultrasound with bone. Because of the inherent complexity of the propagation medium, few analytic solutions exist with practical application. For this reason, ultrasound simulation techniques have been developed and applied to a number of different problems of interest in ultrasonic bone assessment. Both 2D and 3D simulation results will be presented, including the effects of architecture and density on the received waveform, propagation effects of both cortical and trabecular bone, and the relative contributions of scattering and absorption to attenuation in trabecular bone. The results of these simulation studies should lead to improved understanding and ultimately to more effective clinical devices for ultrasound bone assessment. [This work was supported by The Carroll and Milton Petrie Foundation and by SBIR Grant No. 1R43RR16750 from the National Center for Research Resources of the NIH.

  8. An insight in to Paget′s disease of bone

    Directory of Open Access Journals (Sweden)

    Robin Sabharwal

    2014-01-01

    Full Text Available Paget′s disease of bone (PDB is a common disorder which may affect one or many bones. Although many patients are asymptomatic, a variety of symptoms and complications may occur. PDB is a focal disorder of bone turnover characterized by excessive bone resorption coupled with bone formation. PDB begins with a period of increased osteoclastic activity and bone resorption, followed by increased osteoblast production of woven bone that is poorly mineralized. In the final phase of the disease process, dense cortical and trabecular bone deposition predominates, but the bone is sclerotic and poorly organized and lacks the structural integrity and strength of normal bone. This article briefly reviews the etiopathogenesis, clinical radiographic and histological features of Paget′s disease.

  9. Suppressed bone remodeling in black bears conserves energy and bone mass during hibernation.

    Science.gov (United States)

    McGee-Lawrence, Meghan; Buckendahl, Patricia; Carpenter, Caren; Henriksen, Kim; Vaughan, Michael; Donahue, Seth

    2015-07-01

    Decreased physical activity in mammals increases bone turnover and uncouples bone formation from bone resorption, leading to hypercalcemia, hypercalcuria, bone loss and increased fracture risk. Black bears, however, are physically inactive for up to 6 months annually during hibernation without losing cortical or trabecular bone mass. Bears have been shown to preserve trabecular bone volume and architectural parameters and cortical bone strength, porosity and geometrical properties during hibernation. The mechanisms that prevent disuse osteoporosis in bears are unclear as previous studies using histological and serum markers of bone remodeling show conflicting results. However, previous studies used serum markers of bone remodeling that are known to accumulate with decreased renal function, which bears have during hibernation. Therefore, we measured serum bone remodeling markers (BSALP and TRACP) that do not accumulate with decreased renal function, in addition to the concentrations of serum calcium and hormones involved in regulating bone remodeling in hibernating and active bears. Bone resorption and formation markers were decreased during hibernation compared with when bears were physically active, and these findings were supported by histomorphometric analyses of bone biopsies. The serum concentration of cocaine and amphetamine regulated transcript (CART), a hormone known to reduce bone resorption, was 15-fold higher during hibernation. Serum calcium concentration was unchanged between hibernation and non-hibernation seasons. Suppressed and balanced bone resorption and formation in hibernating bears contributes to energy conservation, eucalcemia and the preservation of bone mass and strength, allowing bears to survive prolonged periods of extreme environmental conditions, nutritional deprivation and anuria. © 2015. Published by The Company of Biologists Ltd.

  10. Fabrication and characterization of electrospun osteon mimicking scaffolds for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Andric, T. [Virginia Tech-Wake Forest School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Sampson, A.C. [Chemical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Freeman, J.W., E-mail: jwfreeman@vt.edu [Virginia Tech-Wake Forest School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States)

    2011-01-01

    Skeletal loss and bone deficiencies are a major worldwide problem with over 600,000 procedures performed in the US alone annually, making bone one of the most transplanted tissues, second to blood only. Bone is a composite tissue composed of organic matrix, inorganic bone mineral, and water. Structurally bone is organized into two distinct types: trabecular (or cancellous) and cortical (or compact) bones. Trabecular bone is characterized by an extensive interconnected network of pores. Cortical bone is composed of tightly packed units, called osteons, oriented parallel along to the axis of the bone. While the majority of scaffolds attempt to replicate the structure of the trabecular bone, fewer attempts have been made to create scaffolds to mimic the structure of cortical bone. The aim of this study was to develop a technique to fabricate scaffolds that mimic the organization of an osteon, the structural unit of cortical bone. We successfully built a rotating stage for PGA fibers and utilized it for collecting electrospun nanofibers and creating scaffolds. Resulting scaffolds consisted of concentric layers of electrospun PLLA or gelatin/PLLA nanofibers wrapped around PGA microfiber core with diameters that ranged from 200 to 600 {mu}m. Scaffolds were mineralized by incubation in 10x simulated body fluid, and scaffolds composed of 10%gelatin/PLLA had significantly higher amounts of calcium phosphate. The electrospun scaffolds also supported cellular attachment and proliferation of MC3T3 cells over the period of 28 days.

  11. Ethnic differences in trabecular meshwork height by optical coherence tomography.

    Science.gov (United States)

    Chen, Rebecca I; Barbosa, Diego T; Hsu, Chi-Hsin; Porco, Travis C; Lin, Shan C

    2015-04-01

    Differences in ocular anatomy may contribute to ethnic differences in glaucoma risk. Because the trabecular meshwork (TM) plays an important role in aqueous outflow, its anatomy in relation to at-risk populations may provide insight into a potential contributor to elevated intraocular pressure and thus to probability of glaucoma development. To investigate whether differences exist in TM height between ethnic groups. This prospective study took place from January 1, 2012, to December 31, 2013. Adult patients who self-reported as being of white, Asian, Hispanic, or African American ethnicity were recruited from ophthalmology clinics at the University of California, San Francisco. The TM height was assessed using spectral-domain anterior segment optical coherence tomography. Trabecular meshwork height was measured from the scleral spur to the Schwalbe line. We hypothesized that ethnicities with a higher prevalence of glaucoma would tend to have shorter TM heights. We collected data from 460 eyes of 291 participants after excluding 34 optical coherence tomographic scans owing to poor image quality. The final sample was 32.2% white, 45.1% Asian, 10.5% African American, and 12.1% Hispanic. There were 64.2% women, and the mean age was 68.1 years. The mean (SD) TM height among all eyes included in the study was 836 (131) μm. The mean (SD) TM height was characterized among white (851 [131] μm), Asian (843 [126] μm), Hispanic (822 [147] μm), and African American (771 [118] μm) persons. Ethnicity was not associated with TM height overall (P = .23, linear mixed regression model). However, the TM heights of African American participants (771 μm) were shorter than those of white (851 μm; adjusted difference 95% CI, -119.8 to -8.1; P = .02) and Asian (843 μm; adjusted difference 95% CI, -117.4 to -10.8; P = .02) participants. Although TM height is not associated with ethnicity overall, African American individuals have shorter TM heights compared with Asian and white

  12. Characterization of cellular solids in Ti6Al4V for orthopaedic implant applications: Trabecular titanium.

    Science.gov (United States)

    Marin, E; Fusi, S; Pressacco, M; Paussa, L; Fedrizzi, L

    2010-07-01

    EBM (Electron Beam Melting) technology can be used successfully to obtain cellular solids in metallic biomaterials that can greatly increase osseointegration in arthroprothesis and at the same time maintain good mechanical properties. The investigated structures, called Trabecular Titanium, usually cannot be obtained by traditional machining. Two samples: (A) with a smaller single cell area and, (B) with a bigger single cell area, were produced and studied in this project. They have been completely characterized and compared with the results in similar literature pertinent to Ti6Al4V EBM structures. Relative density was evaluated using different methods, the mean diameter of the open porosities was calculated by Scanning Electron Microscope images; the composition was evaluated using Energy-Dispersive X-Ray Spectroscopy; the microstructure (alpha-beta) was investigated using chemical etching and, the mechanical proprieties were investigated using UMTS. The mean porosity values resulted comparable with spongy bone (63% for A and 72% for B). The mean diameter of the single porosity (650 mum for A and 1400 mum for B) resulted compatible with the osseointegration data from the literature, in particular for sample A. The Vickers micro-hardness tests and the chemical etching demonstrated that the structure is fine, uniform and well distributed. The mechanical test proved that sample (A) was more resistant than sample (B), but sample (B) showed an elastic modulus almost equal to the value of spongy bone. The results of this study suggest that the two Ti6Al4V cellular solids can be used in biomedical applications to promote osseointegration demonstrating that they maybe successfully used in prosthetic implants. Additional implant results will be published in the near future. Copyright 2010 Elsevier Ltd. All rights reserved.

  13. Medullar fat influences texture analysis of trabecular microarchitecture on X-ray radiographs

    International Nuclear Information System (INIS)

    Chappard, Daniel; Pascaretti-Grizon, Florence; Gallois, Yves; Mercier, Philippe; Basle, Michel F.; Audran, Maurice

    2006-01-01

    Alteration of trabecular architecture is a predictor of fracture risk in osteoporosis. Until now, microarchitecture analysis is difficult to evaluate in routine clinical practice for osteoporosis. Texture analysis on X-ray images has been advocated to be a suitable method to assess microarchitecture in bone diseases. The X-ray acquisition conditions have been often taken into consideration; however, the influence of anatomical conditions on texture parameters has received little interest. Because fat is a well-known problem with computed tomography and densitometry, we have designed a cadaver study to compare the influence of marrow lipids on numerous texture parameters. Twenty-one human distal radii were obtained, radiographed, and analyzed using a software that measures: heterogeneity, skeletonized parameters, run-lengths and fractal dimensions. Texture parameters were measured before, and after an extensive delipidation period lasting 3 weeks. Quality of the radiographs was improved after defatting. Delipidation had a very significant effect on measurements: afterwards defatting, the images were less blurred, and a better delineation of trabeculae and marrow cavities was obtained. This provoked an increase of parameters based on the grey level distribution but had no influence on parameters describing the reticulated honeycomb microarchitecture of the trabeculae (i.e., fractal dimension). Some parameters appeared anisotropy-sensitive, due to the different constitution and size of the trabeculae. The fat content of bone marrow induces noise that can modify some texture parameters. One should take into account the fat content of the marrow when using texture analysis to compare patients with osteoporosis due to various etiologies

  14. Accelerated bone ingrowth by local delivery of Zinc from bioactive ...

    African Journals Online (AJOL)

    2015-10-19

    Oct 19, 2015 ... Aims: This study aims to evaluate in vivo the performance therapy of zinc-doped bioactive glass (BG-Zn) and ... Keywords: zinc metallic ion; bioactive glass; osteoporosis; trabecular bone architecture; mechanical property; oxidative stress ..... Ducheyne P, Qiu Q. Bioactive ceramics: the effect of surface.

  15. Body composition and reproductive function exert unique influences on indices of bone health in exercising women.

    Science.gov (United States)

    Mallinson, Rebecca J; Williams, Nancy I; Hill, Brenna R; De Souza, Mary Jane

    2013-09-01

    Reproductive function, metabolic hormones, and lean mass have been observed to influence bone metabolism and bone mass. It is unclear, however, if reproductive, metabolic and body composition factors play unique roles in the clinical measures of areal bone mineral density (aBMD) and bone geometry in exercising women. This study compares lumbar spine bone mineral apparent density (BMAD) and estimates of femoral neck cross-sectional moment of inertia (CSMI) and cross-sectional area (CSA) between exercising ovulatory (Ov) and amenorrheic (Amen) women. It also explores the respective roles of reproductive function, metabolic status, and body composition on aBMD, lumbar spine BMAD and femoral neck CSMI and CSA, which are surrogate measures of bone strength. Among exercising women aged 18-30 years, body composition, aBMD, and estimates of femoral neck CSMI and CSA were assessed by dual-energy x-ray absorptiometry. Lumbar spine BMAD was calculated from bone mineral content and area. Estrone-1-glucuronide (E1G) and pregnanediol glucuronide were measured in daily urine samples collected for one cycle or monitoring period. Fasting blood samples were collected for measurement of leptin and total triiodothyronine. Ov (n = 37) and Amen (n = 45) women aged 22.3 ± 0.5 years did not differ in body mass, body mass index, and lean mass; however, Ov women had significantly higher percent body fat than Amen women. Lumbar spine aBMD and BMAD were significantly lower in Amen women compared to Ov women (p < 0.001); however, femoral neck CSA and CSMI were not different between groups. E1G cycle mean and age of menarche were the strongest predictors of lumbar spine aBMD and BMAD, together explaining 25.5% and 22.7% of the variance, respectively. Lean mass was the strongest predictor of total hip and femoral neck aBMD as well as femoral neck CSMI and CSA, explaining 8.5-34.8% of the variance. Upon consideration of several potential osteogenic stimuli, reproductive function appears to play

  16. Bone tumor

    Science.gov (United States)

    Tumor - bone; Bone cancer; Primary bone tumor; Secondary bone tumor; Bone tumor - benign ... The cause of bone tumors is unknown. They often occur in areas of the bone that grow rapidly. Possible causes include: Genetic defects ...

  17. Enhancement of Bone Marrow-Derived Mesenchymal Stem Cell Osteogenesis and New Bone Formation in Rats by Obtusilactone A

    Directory of Open Access Journals (Sweden)

    Yi-Hsiung Lin

    2017-11-01

    Full Text Available The natural pure compound obtusilactone A (OA was identified in Cinnamomum kotoense Kanehira & Sasaki, and shows effective anti-cancer activity. We studied the effect of OA on osteogenesis of bone marrow-derived mesenchymal stem cells (BMSCs. OA possesses biocompatibility, stimulates Alkaline Phosphatase (ALP activity and facilitates mineralization of BMSCs. Expression of osteogenesis markers BMP2, Runx2, Collagen I, and Osteocalcin was enhanced in OA-treated BMSCs. An in vivo rat model with local administration of OA via needle implantation to bone marrow-residing BMSCs revealed that OA increased the new bone formation and trabecular bone volume in tibias. Micro-CT images and H&E staining showed more trabecular bone at the needle-implanted site in the OA group than the normal saline group. Thus, OA confers an osteoinductive effect on BMSCs via induction of osteogenic marker gene expression, such as BMP2 and Runx2 expression and subsequently elevates ALP activity and mineralization, followed by enhanced trabecular bone formation in rat tibias. Therefore, OA is a potential osteoinductive drug to stimulate new bone formation by BMSCs.

  18. Are bi-axial proximal sesamoid bone fractures in the British Thoroughbred racehorse a bone fatigue related fracture? A histological study.

    Science.gov (United States)

    Kristoffersen, M; Hetzel, U; Parkin, T D H; Singer, E R

    2010-01-01

    To investigate whether microfractures and alterations in the trabecular bone area are associated with catastrophic bi-axial proximal sesamoid bone fractures (PSBF). Proximal sesamoid bones (PSB) from 10 racehorses with PSBF and from 10 control racehorses without musculoskeletal injury were examined using the bulk basic fuchsin method. Bone histomorphometric and microfracture analysis was performed, and cases and controls compared using two-sample t-test, paired t-test, and Mann-Whitney U test. There was no significant difference in the microfracture density and the trabecular bone area between bones from case and control horses, and between fractured and non-fractured bones in case horses. Microfracture density was low in the areas of the PSB examined. Microfracture density was not significantly different between groups, indicating that propagation of micro-cracks is an unlikely predisposing pathologic alteration in PSBF in British racehorses. There was no significant difference in the bone surface area between groups, which one would expect if modelling, adaptation and an increase in bone density were associated with PSBF fracture in the case horses. Therefore, PSBF in the British racehorse does not appear to be associated with microfractures of the trabecular bone of the PSB. The PSB fractures might represent an acute monotonic fracture; however, the aetiology of the fractures remains unknown with additional research required.

  19. Decreased Bone Formation Explains Osteoporosis in a Genetic Mouse Model of Hemochromatosiss.

    Directory of Open Access Journals (Sweden)

    Mathilde Doyard

    Full Text Available Osteoporosis may complicate iron overload diseases such as genetic hemochromatosis. However, molecular mechanisms involved in the iron-related osteoporosis remains poorly understood. Recent in vitro studies support a role of osteoblast impairment in iron-related osteoporosis. Our aim was to analyse the impact of excess iron in Hfe-/- mice on osteoblast activity and on bone microarchitecture. We studied the bone formation rate, a dynamic parameter reflecting osteoblast activity, and the bone phenotype of Hfe-/- male mice, a mouse model of human hemochromatosis, by using histomorphometry. Hfe-/- animals were sacrificed at 6 months and compared to controls. We found that bone contains excess iron associated with increased hepatic iron concentration in Hfe-/- mice. We have shown that animals with iron overload have decreased bone formation rate, suggesting a direct impact of iron excess on active osteoblasts number. For bone mass parameters, we showed that iron deposition was associated with bone loss by producing microarchitectural impairment with a decreased tendency in bone trabecular volume and trabecular number. A disorganization of trabecular network was found with marrow spaces increased, which was confirmed by enhanced trabecular separation and star volume of marrow spaces. These microarchitectural changes led to a loss of connectivity and complexity in the trabecular network, which was confirmed by decreased interconnectivity index and increased Minkowski's fractal dimension. Our results suggest for the first time in a genetic hemochromatosis mouse model, that iron overload decreases bone formation and leads to alterations in bone mass and microarchitecture. These observations support a negative effect of iron on osteoblast recruitment and/or function, which may contribute to iron-related osteoporosis.

  20. Sclerostin Blockade and Zoledronic Acid Improve Bone Mass and Strength in Male Mice With Exogenous Hyperthyroidism.

    Science.gov (United States)

    Tsourdi, Elena; Lademann, Franziska; Ominsky, Michael S; Rijntjes, Eddy; Köhrle, Josef; Misof, Barbara M; Roschger, Paul; Klaushofer, Klaus; Hofbauer, Lorenz C; Rauner, Martina

    2017-11-01

    Hyperthyroidism in mice is associated with low bone mass, high bone turnover, and high concentrations of sclerostin, a potent Wnt inhibitor. Here, we explored the effects of either increasing bone formation with sclerostin antibodies (Scl-Ab) or reducing bone turnover with bisphosphonates on bone mass and strength in hyperthyroid mice. Twelve-week-old C57BL/6 male mice were rendered hyperthyroid using l-thyroxine (T4; 1.2 µg/mL added to the drinking water) and treated with 20 mg/kg Scl-Ab twice weekly or 100 µg/kg zoledronic acid (ZOL) once weekly or phosphate-buffered saline for 4 weeks. Hyperthyroid mice displayed a lower trabecular bone volume at the spine (-42%, P hyperthyroid mice increased trabecular bone volume at the spine by threefold and twofold, respectively. Serum bone formation and resorption markers were increased in hyperthyroid mice and suppressed by treatment with ZOL but not Scl-Ab. Trabecular bone stiffness at the lumbar vertebra was 63% lower in hyperthyroid mice (P hyperthyroidism, was increased by Scl-Ab by 71% and ZOL by 22% (both P hyperthyroid mice was restored by treatment with Scl-Ab and ZOL. Thus, bone-forming and antiresorptive drugs prevent bone loss in hyperthyroid mice via different mechanisms. Copyright © 2017 Endocrine Society.

  1. Micro-computed tomography assessment of human alveolar bone: bone density and three-dimensional micro-architecture.

    Science.gov (United States)

    Kim, Yoon Jeong; Henkin, Jeffrey

    2015-04-01

    Micro-computed tomography (micro-CT) is a valuable means to evaluate and secure information related to bone density and quality in human necropsy samples and small live animals. The aim of this study was to assess the bone density of the alveolar jaw bones in human cadaver, using micro-CT. The correlation between bone density and three-dimensional micro architecture of trabecular bone was evaluated. Thirty-four human cadaver jaw bone specimens were harvested. Each specimen was scanned with micro-CT at resolution of 10.5 μm. The bone volume fraction (BV/TV) and the bone mineral density (BMD) value within a volume of interest were measured. The three-dimensional micro architecture of trabecular bone was assessed. All the parameters in the maxilla and the mandible were subject to comparison. The variables for the bone density and the three-dimensional micro architecture were analyzed for nonparametric correlation using Spearman's rho at the significance level of p architecture parameters were consistently higher in the mandible, up to 3.3 times greater than those in the maxilla. The most linear correlation was observed between BV/TV and BMD, with Spearman's rho = 0.99 (p = .01). Both BV/TV and BMD were highly correlated with all micro architecture parameters with Spearman's rho above 0.74 (p = .01). Two aspects of bone density using micro-CT, the BV/TV and BMD, are highly correlated with three-dimensional micro architecture parameters, which represent the quality of trabecular bone. This noninvasive method may adequately enhance evaluation of the alveolar bone. © 2013 Wiley Periodicals, Inc.

  2. Osteoclast inhibition impairs chondrosarcoma growth and bone destruction.

    Science.gov (United States)

    Otero, Jesse E; Stevens, Jeff W; Malandra, Allison E; Fredericks, Douglas C; Odgren, Paul R; Buckwalter, Joseph A; Morcuende, Jose

    2014-12-01

    Because Chondrosarcoma is resistant to available chemotherapy and radiation regimens, wide resection is the mainstay in treatment, which frequently results in high morbidity and which may not prevent local recurrence. There is a clear need for improved adjuvant treatment of this malignancy. We have observed the presence of osteoclasts in the microenvironment of chondrosarcoma in human pathological specimens. We utilized the Swarm rat chondrosarcoma (SRC) model to test the hypothesis that osteoclasts affect chondrosarcoma pathogenesis. We implanted SRC tumors in tibia of Sprague-Dawley rats and analyzed bone histologically and radiographically for bone destruction and tumor growth. At three weeks, tumors invaded local bone causing cortical disruption and trabecular resorption. Bone destruction was accompanied by increased osteoclast number and resorbed bone surface. Treatment of rats with the zoledronic acid prevented cortical destruction, inhibited trabecular resorption, and resulted in decreased tumor volume in bone. To confirm that inhibition of osteoclasts per se, and not off-target effects of drug, was responsible for the prevention of tumor growth and bone destruction, we implanted SRC into osteopetrotic rat tibia. SRC-induced bone destruction and tumor growth were impaired in osteopetrotic bone compared with control bone. The results from our animal model demonstrate that osteoclasts contribute to chondrosarcoma-mediated bone destruction and tumor growth and may represent a therapeutic target in particular chondrosarcoma patients. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  3. Various effects of antidepressant drugs on bone microarchitectecture, mechanical properties and bone remodeling

    International Nuclear Information System (INIS)

    Bonnet, N.; Bernard, P.; Beaupied, H; Bizot, J.C.; Trovero, F.; Courteix, D.; Benhamou, C.L.

    2007-01-01

    The aim of this study was to evaluate the effects of various drugs which present antidepressant properties: selective serotonin-reuptake inhibitors (SSRIs, fluoxetine), serotonin and noradrenaline-reuptake inhibitors (Desipramine) and phosphodiesterase inhibitors (PDE, rolipram and tofisopam) on bone microarchitecture and biomechanical properties. Twelve female mice were studied per group starting at an age of 10 weeks. During 4 weeks, they received subcutaneously either placebo or 20 mg kg -1 day -1 of desipramine, fluoxetine or 10 mg kg -1 day -1 of rolipram or tofisopam. Serum Osteocalcin and CTx were evaluated by ELISA. Bone microarchitecture of the distal femur was characterized by X-ray microCT (Skyscan1072). Mechanical properties were assessed by three-point bending test (Instron 4501) and antidepressant efficacy by forced swimming and open field tests. Fluoxetine displayed lower TbTh (- 6.1%, p -1 , 6431 ± 1182 MPa) than in placebo (101 ± 9 N mm -1 , 8441 ± 1180 MPa). Bone markers indicated a significantly higher bone formation in tofisopam (+ 8.6%) and a lower in fluoxetine (- 56.1%) compared to placebo. These data suggest deleterious effects for SSRIs, both on trabecular and cortical bone and a positive effect of PDE inhibitors on trabecular bone. Furthermore tofisopam anabolic effect in terms of bone markers, suggests a potential therapeutic effect of the PDE inhibitors on bone

  4. Methodologies for the measurement of bone density and their precision and accuracy

    International Nuclear Information System (INIS)

    Goodwin, P.N.

    1987-01-01

    Radiographic methods of determining bone density have been available for many years, but recently most of the efforts in this field have focused on the development of instruments which would accurately and automatically measure bone density by absorption, or by the use of x-ray computed tomography (CT). Single energy absorptiometers using I-125 have been available for some years, and have been used primarily for measurements on the radius, although recently equipment for measuring the os calcis has become available. Accuracy of single energy measurements is about 3% to 5%; precision, which has been poor because of the difficulty of exact repositioning, has recently been improved by automatic methods so that it now approaches 1% or better. Dual energy sources offer the advantages of greater accuracy and the ability to measure the spine and other large bones. A number of dual energy scanners are now on the market, mostly using gadolinium-153 as a source. Dual energy scanning is capable of an accuracy of a few percent, but the precision when scanning patients can vary widely, due to the difficulty of comparing exactly the same areas; 2 to 4% would appear to be typical. Quantitative computed tomography (QCT) can be used to directly measure the trabecular bone within the vertebral body. The accuracy of single-energy QCT is affected by the amount of marrow fat present, which can lead to underestimations of 10% or more. An increase in marrow fat would cause an apparent decrease in bone mineral. However, the precision can be quite good, 1% or 2% on phantoms, and nearly as good on patients when four vertebrae are averaged. Dual energy scanning can correct for the presence of fat, but is less precise, and not available on all CT units. 52 references

  5. Effect of age on bone mineral density and micro architecture in the radius and tibia of horses: An Xtreme computed tomographic study

    Directory of Open Access Journals (Sweden)

    Schmidlin A

    2008-01-01

    Full Text Available Abstract Background The effect of age on the bone mineral density and microarchitecture of the equine radius and tibia was investigated. Fifty-six bones from 15 horses aged four to 21 years were used. There were nine geldings and six mares, and none of the horses had any disease influencing bone properties. Xtreme computed tomography was used to evaluate a 9-mm segment of the diaphysis and metaphysis of each bone. The following variables were determined: length of the bone, circumference and diameter in the frontal and sagittal planes in the middle of the bone. Diaphysis: total volume, bone volume, bone volume ratio, slice area, bone area, marrow area, cortical and marrow thickness, bone mineral density, polar moment of inertia of the cortex. Metaphysis: total area, bone area, cortical bone area, cortical thickness, bone mineral density, bone mineral density in the cortex, bone mineral density in the trabecular region, trabecular number, trabecular thickness, trabecular separation, polar moment of inertia of the metaphysis, polar moment of inertia of the cortex of the metaphysis. Results Bone density and microarchitecture were not affected by breed or gender. However, the microarchitecture varied with the age of the horse; the number of trabeculae decreased significantly and the distance between trabeculae increased significantly with increasing age. There were no significant differences between bones of the left and right limbs or between the radius and tibia. Conclusion The variables investigated did not differ between geldings and mares. However, there were age-related changes in the microstructure of the bones. Further experimental studies are necessary to determine whether these changes reduce bone strength. Age-related changes in the bones were seen and may explain the higher incidence of fractures and fissures in older horses.

  6. Effect of age on bone mineral density and micro architecture in the radius and tibia of horses: An Xtreme computed tomographic study

    Science.gov (United States)

    Fürst, A; Meier, D; Michel, S; Schmidlin, A; Held, L; Laib, A

    2008-01-01

    Background The effect of age on the bone mineral density and microarchitecture of the equine radius and tibia was investigated. Fifty-six bones from 15 horses aged four to 21 years were used. There were nine geldings and six mares, and none of the horses had any disease influencing bone properties. Xtreme computed tomography was used to evaluate a 9-mm segment of the diaphysis and metaphysis of each bone. The following variables were determined: length of the bone, circumference and diameter in the frontal and sagittal planes in the middle of the bone. Diaphysis: total volume, bone volume, bone volume ratio, slice area, bone area, marrow area, cortical and marrow thickness, bone mineral density, polar moment of inertia of the cortex. Metaphysis: total area, bone area, cortical bone area, cortical thickness, bone mineral density, bone mineral density in the cortex, bone mineral density in the trabecular region, trabecular number, trabecular thickness, trabecular separation, polar moment of inertia of the metaphysis, polar moment of inertia of the cortex of the metaphysis. Results Bone density and microarchitecture were not affected by breed or gender. However, the microarchitecture varied with the age of the horse; the number of trabeculae decreased significantly and the distance between trabeculae increased significantly with increasing age. There were no significant differences between bones of the left and right limbs or between the radius and tibia. Conclusion The variables investigated did not differ between geldings and mares. However, there were age-related changes in the microstructure of the bones. Further experimental studies are necessary to determine whether these changes reduce bone strength. Age-related changes in the bones were seen and may explain the higher incidence of fractures and fissures in older horses. PMID:18221526

  7. Effect of age on bone mineral density and micro architecture in the radius and tibia of horses: an Xtreme computed tomographic study.

    Science.gov (United States)

    Fürst, A; Meier, D; Michel, S; Schmidlin, A; Held, L; Laib, A

    2008-01-25

    The effect of age on the bone mineral density and microarchitecture of the equine radius and tibia was investigated. Fifty-six bones from 15 horses aged four to 21 years were used. There were nine geldings and six mares, and none of the horses had any disease influencing bone properties. Xtreme computed tomography was used to evaluate a 9-mm segment of the diaphysis and metaphysis of each bone. The following variables were determined: length of the bone, circumference and diameter in the frontal and sagittal planes in the middle of the bone.Diaphysis: total volume, bone volume, bone volume ratio, slice area, bone area, marrow area, cortical and marrow thickness, bone mineral density, polar moment of inertia of the cortex.Metaphysis: total area, bone area, cortical bone area, cortical thickness, bone mineral density, bone mineral density in the cortex, bone mineral density in the trabecular region, trabecular number, trabecular thickness, trabecular separation, polar moment of inertia of the metaphysis, polar moment of inertia of the cortex of the metaphysis. Bone density and microarchitecture were not affected by breed or gender. However, the microarchitecture varied with the age of the horse; the number of trabeculae decreased significantly and the distance between trabeculae increased significantly with increasing age. There were no significant differences between bones of the left and right limbs or between the radius and tibia. The variables investigated did not differ between geldings and mares. However, there were age-related changes in the microstructure of the bones. Further experimental studies are necessary to determine whether these changes reduce bone strength. Age-related changes in the bones were seen and may explain the higher incidence of fractures and fissures in older horses.

  8. PTH prevents the adverse effects of focal radiation on bone architecture in young rats.

    Science.gov (United States)

    Chandra, Abhishek; Lan, Shenghui; Zhu, Ji; Lin, Tiao; Zhang, Xianrong; Siclari, Valerie A; Altman, Allison R; Cengel, Keith A; Liu, X Sherry; Qin, Ling

    2013-08-01

    Radiation therapy is a common treatment regimen for cancer patients. However, its adverse effects on the neighboring bone could lead to fractures with a great impact on quality of life. The underlying mechanism is still elusive and there is no preventive or curative solution for this bone loss. Parathyroid hormone (PTH) is a current therapy for osteoporosis that has potent anabolic effects on bone. In this study, we found that focal radiation from frequent scans of the right tibiae in 1-month-old rats by micro-computed tomography severely decreased trabecular bone mass and deteriorated bone structure. Interestingly, PTH daily injections remarkably improved trabecular bone in the radiated tibiae with increases in trabecular number, thickness, connectivity, structure model index and stiffness, and a decrease in trabecular separation. Histomorphometric analysis revealed that radiation mainly decreased the number of osteoblasts and impaired their mineralization activity but had little effects on osteoclasts. PTH reversed these adverse effects and greatly increased bone formation to a similar level in both radiated and non-radiated bones. Furthermore, PTH protects bone marrow mesenchymal stem cells from radiation-induced damage, including a decrease in number and an increase in adipogenic differentiation. While radiation generated the same amount of free radicals in the bone marrow of vehicle-treated and PTH-treated animals, the percentage of apoptotic bone marrow cells was significantly attenuated in the PTH group. Taken together, our data demonstrate a radioprotective effect of PTH on bone structure and bone marrow and shed new light on a possible clinical application of anabolic treatment in radiotherapy. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Design and properties of 3D scaffolds for bone tissue engineering.

    Science.gov (United States)

    Gómez, S; Vlad, M D; López, J; Fernández, E

    2016-09-15

    In this study, the Voronoi tessellation method has been used to design novel bone like three dimension (3D) porous scaffolds. The Voronoi method has been processed with computer design software to obtain 3D virtual isotropic porous interconnected models, exactly matching the main histomorphometric indices of trabecular bone (trabecular thickness, trabecular separation, trabecular number, bone volume to total volume ratio, bone surface to bone volume ratio, etc.). These bone like models have been further computed for mechanical (elastic modulus) and fluid mass transport (permeability) properties. The results show that the final properties of the scaffolds can be controlled during their microstructure and histomorphometric initial design stage. It is also shown that final properties can be tuned during the design stage to exactly match those of trabecular natural bone. Moreover, identical total porosity models can be designed with quite different specific bone surface area and thus, this specific microstructural feature can be used to favour cell adhesion, migration and, ultimately, new bone apposition (i.e. osteoconduction). Once the virtual models are fully characterized and optimized, these can be easily 3D printed by additive manufacturing and/or stereolitography technologies. The significance of this article goes far beyond the specific objectives on which it is focussed. In fact, it shows, in a guided way, the entire novel process that can be followed to design graded porous implants, whatever its external shape and geometry, but internally tuned to the exact histomorphometric indices needed to match natural human tissues microstructures and, consequently, their mechanical and fluid properties, among others. The significance is even more relevant nowadays thanks to the available new computing and design software that is easily linked to the 3D printing new technologies. It is this transversality, at the frontier of different disciplines, the main characteristic

  10. Comparative study of longitudinal changes in peri-implant bone microstructure

    International Nuclear Information System (INIS)

    Suzuki, Yusuke; Matsunaga, Satoru; Abe, Shinichi; Ide, Yoshinobu; Usami, Akinobu

    2010-01-01

    The load applied to an implant is directly transmitted to the jaw and is considered to be one of the causes of remodeling of internal trabecular bones. However, the longitudinal changes during loading and the rearrangement of the trabecular bone structure are mostly unknown. The aim of this study was to clarify the changes in internal jaw bone structure longitudinally during natural tooth eruption as well as tooth extraction and post-implantation periods in a dog model by micro computed tomography (micro-CT). Maxillae of 16 male beagle dogs were used in this study. First, 4 dogs with all maxillary molar teeth erupted were euthanized as a control group. Next, 6 teeth consisting of the bilateral maxillary fourth premolars, and first and second molars were extracted from each of the 12 dogs. Then, 4 dogs of the tooth-extracted group were euthanized 3 months after extraction of the teeth. At this time, three implants were inserted in the left side of the maxilla of the remaining 8 dogs, and the superstructures were placed after 3 months. Four of these 8 dogs with implants were euthanized at 3 months and the other 4 at 1 year after placement of the superstructure. Then, the maxillary bone was removed from each dog as a specimen and sequential micro-CT images were taken. After reconstruction of three-dimensional images, morphological and metrical observation of the jaw trabecular bone structure was performed. A decrease of the trabecular bone in the tooth-extracted group was morphologically and morphometrically observed, whereas the implanted group showed thick, rich trabecular bone. Although a longitudinal decrease in the bone tissue volume was recognized both in the tooth-extracted and the implanted groups, the amount was smaller in the implanted group than in the tooth-extracted group. The results suggested that the application of load by implants in the case of tooth loss inhibits resorption of the alveolar bone and prevents thinning of the jaw. (author)

  11. Effects of 1.8 GHz radiofrequency field on microstructure and bone metabolism of femur in mice.

    Science.gov (United States)

    Guo, Ling; Zhang, Jun-Ping; Zhang, Ke-Ying; Wang, Huan-Bo; Wang, Huan; An, Guang-Zhou; Zhou, Yan; Meng, Guo-Lin; Ding, Gui-Rong

    2018-04-30

    To investigate the effects of 1.8 GHz radiofrequency (RF) field on bone microstructure and metabolism of femur in mice, C57BL/6 mice (male, age 4 weeks) were whole-body exposed or sham exposed to 1.8 GHz RF field. Specific absorption rates of whole body and bone were approximately 2.70 and 1.14 W/kg (6 h/day for 28 days). After exposure, microstructure and morphology of femur were observed by microcomputed tomography (micro-CT), Hematoxylin and Eosin (HE) and Masson staining. Subsequently, bone parameters were calculated directly from the reconstructed images, including structure model index, bone mineral density, trabecular bone volume/total volume, connectivity density, trabecular number, trabecular thickness, and trabecular separation. Biomarkers that reflect bone metabolism, such as serum total alkaline phosphatase (ALP), bone-specific alkaline phosphatase (BALP), and tartrate-resistant acid phosphatase 5b (TRACP-5b), were determined by biochemical assay methods. Micro-CT and histology results showed that there was no significant change in bone microstructure and the above parameters in RF group, compared with sham group. The activity of serum ALP and BALP increased 29.47% and 16.82%, respectively, in RF group, compared with sham group (P microstructure; however, it might promote metabolic function of osteoblasts in mice. Bioelectromagnetics. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

  12. Analysis of the of bones through 3D computerized tomography; Analise de estrutura ossea atraves de microtomografia computadorizada 3D

    Energy Technology Data Exchange (ETDEWEB)

    Lima, I.; Lopes, R.T. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear; Oliveira, L.F. [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Fisica. Dept. de Fisica Aplicada e Termodinamica; Alves, J.M. [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Escola de Engenharia

    2009-03-15

    This work shows the analysis of the internal structure of the bones samples through 3D micro tomography technique (3D-{mu}TC). The comprehension of the bone structure is particularly important when related to osteoporosis diagnosis because this implies in a deterioration of the trabecular bone architecture, which increases the fragility and the possibility to have bone fractures. Two bone samples (human calcaneous and Wistar rat femur) were used, and the method was a radiographic system in real time with an X Ray microfocus tube. The quantifications parameters are based on stereological principles and they are five: a bone volume fraction, trabecular number, the ratio between surface and bone volume, the trabecular thickness and the trabecular separation. The quantifications were done with a program developed especially for this purpose in Nuclear Instrumentation Laboratory - COPPE/UFRJ. This program uses as input the 3D reconstructions images and generates a table with the quantifications. The results of the human calcaneous quantifications are presented in tables 1 and 2, and the 3D reconstructions are illustrated in Figure 5. The Figure 6 illustrate the 2D reconstructed image and the Figure 7 the 3D visualization respectively of the Wistar femur sample. The obtained results show that the 3D-{mu}TC is a powerful technique that can be used to analyze bone microstructures. (author)

  13. The initial instability of cemented and non-cemented femoral stems fixated with a bone grafting technique

    NARCIS (Netherlands)

    Schreurs, B.W.; Huiskes, H.W.J.; Slooff, T.J.J.H.

    1994-01-01

    To reconstruct intramedullary bone stock in revision surgery of failed total hip arthroplasties, a method was developed using impacted trabecular bone grafts. In an in vitro model with femora of the goat, the initial stabilities of both cemented and non-cemented hydroxylapatite-coated stems in this

  14. Vertebral body trabecular density at the thoracolumbar junction using quantitative computed tomography

    International Nuclear Information System (INIS)

    Singer, K.P.; Breidahl, P.D.; Royal Perth Hospital

    1990-01-01

    Quantitative computed tomography was used to assess vertebral trabecular density in 26 post-mortem spines from individuals aged between 14 and 80 years. All vertebrae from T10 to L1 were scanned transversely near the mid-vertebral level with calculations of trabecular density in HUs averaged and referenced to a mineral equivalent phantom. An age-related decline in trabecular density was recorded (r=0.55, p<0.0001). Density measures from the anterior aspect of the vertebral body were significantly greater than from postero-lateral regions. From T10 to L1, there was a significant decrease in trabecular density, whereas density measures multiplied by vertebral body cross-sectional area were constant. Predictions of vertebral compressive strength using quantitative computed tomography may become more accurate by increasing the sampling area per scan and including vertebral body cross-sectional area as part of the radiologic assessment. (orig.)

  15. Does simvastatin stimulate bone formation in vivo?

    Directory of Open Access Journals (Sweden)

    Chorev Michael

    2003-04-01

    Full Text Available Abstract Background Statins, potent compounds that inhibit cholesterol synthesis in the liver have been reported to induce bone formation, both in tissue culture and in rats and mice. To re-examine potential anabolic effects of statins on bone formation, we compared the activity of simvastatin (SVS to the known anabolic effects of PTH in an established model of ovariectomized (OVX Swiss-Webster mice. Methods Mice were ovariectomized at 12 weeks of age (T0, remained untreated for 5 weeks to allow development of osteopenia (T5, followed by treatment for 8 weeks (T13. Whole, trabecular and cortical femoral bone was analyzed by micro-computed tomography (micro CT. Liquid chromatography/mass spectrometry (LC/MS was used to detect the presence of SVS and its active metabolite, simvastatin β-hydroxy acid (SVS-OH in the mouse serum. Results Trabecular BV/TV at T13 was 4.2 fold higher in animals treated with PTH (80 micro-g/kg/day compared to the OVX-vehicle treated group (p in vivo study. Conclusions While PTH demonstrated the expected anabolic effect on bone, SVS failed to stimulate bone formation, despite our verification by LC/MS of the active SVS-OH metabolite in mouse serum. While statins have clear effects on bone formation in vitro, the formulation of existing 'liver-targeted' statins requires further refinement for efficacy in vivo.

  16. Three-axial strain controlled testing applied to bone specimens from the proximal tibial epiphysis

    DEFF Research Database (Denmark)

    Linde, F.; Pongsoipetch, B.; Frich, Lars Henrik

    1990-01-01

    Reproducibility of the determination of Young's modulus and energy absorption along the three axes of trabecular bone cubes was analysed by non-destructive compression to 0.5% strain using different testing protocols. These protocols included testing with and without pre-conditioning to a viscoel......Reproducibility of the determination of Young's modulus and energy absorption along the three axes of trabecular bone cubes was analysed by non-destructive compression to 0.5% strain using different testing protocols. These protocols included testing with and without pre...

  17. Association Between Insulin Resistance and Bone Structure in Nondiabetic Postmenopausal Women

    DEFF Research Database (Denmark)

    Shanbhogue, Vikram V; Finkelstein, Joel S; Bouxsein, Mary L

    2016-01-01

    computed tomography was used to assess bone density and microstructure at the distal radius and tibia. Fasting insulin and glucose was measured and insulin resistance was estimated using homeostasis model assessment of insulin resistance (HOMA-IR) with higher values indicating greater insulin resistance....... RESULTS: There was a negative association between HOMA-IR and bone size and a positive association between HOMA-IR and total vBMD, trabecular vBMD, trabecular thickness and cortical thickness at the radius and tibia. These relationships remained even after adjusting for body weight and other potential...

  18. Genetic ablation of CD68 results in mice with increased bone and dysfunctional osteoclasts.

    Directory of Open Access Journals (Sweden)

    Jason W Ashley

    Full Text Available CD68 is a member of the lysosome associated membrane protein (LAMP family that is restricted in its expression to cells of the monocyte/macrophage lineage. This lineage restriction includes osteoclasts, and, while previous studies of CD68 in macrophages and dendritic cells have proposed roles in lipid metabolism, phagocytosis, and antigen presentation, the expression and function of CD68 in osteoclasts have not been explored. In this study, we investigated the expression and localization of CD68 in macrophages and osteoclasts in response to the monocyte/macrophage-colony stimulating factor (M-CSF and the receptor activator of NF-κB ligand (RANKL. We found that M-CSF stimulates CD68 expression and RANKL alters the apparent molecular weight of CD68 as measured by Western immunoblotting. In addition, we explored the significance of CD68 expression in osteoclasts by generating mice that lack expression of CD68. These mice have increased trabecular bone, and in vitro assessment of CD68(-/- osteoclasts revealed that, in the absence of CD68, osteoclasts demonstrate an accumulation of intracellular vesicle-like structures, and do not efficiently resorb bone. These findings demonstrate a role for CD68 in the function of osteoclasts, and future studies will determine the mechanistic nature of the defects seen in CD68(-/- osteoclasts.

  19. Association Between Insulin Resistance and Bone Structure in Nondiabetic Postmenopausal Women

    Science.gov (United States)

    Finkelstein, Joel S.; Bouxsein, Mary L.; Yu, Elaine W.

    2016-01-01

    Context: The clinical consequences of insulin resistance and hyperinsulinemia on bone remain largely unknown. Objective: The objective of the study was to evaluate the effect of insulin resistance on peripheral bone geometry, volumetric bone mineral density (vBMD), bone microarchitecture, and estimated bone strength. Design, Setting, and Participants: This cross-sectional study included 146 postmenopausal, nondiabetic Caucasian women (mean age 60.3 ± 2.7 y) who were participating in the Study of Women's Health Across the Nation. Interventions: There were no interventions. Main Outcome Measures: High-resolution peripheral quantitative computed tomography was used to assess bone density and microstructure at the distal radius and tibia. Fasting insulin and glucose were measured and insulin resistance was estimated using homeostasis model assessment of insulin resistance (HOMA-IR), with higher values indicating greater insulin resistance. Results: There was a negative association between HOMA-IR and bone size and a positive association between HOMA-IR and total vBMD, trabecular vBMD, trabecular thickness, and cortical thickness at the radius and tibia. These relationships remained, even after adjusting for body weight and other potential covariates (eg, time since menopause, cigarette smoking, physical activity, prior use of osteoporosis medications or glucocorticoids). Conclusions: In nondiabetic, postmenopausal women, insulin resistance was associated with smaller bone size, greater volumetric bone mineral density, and generally favorable bone microarchitecture at weight-bearing and nonweight-bearing skeletal sites. These associations were independent of body weight and other potential covariates, suggesting that hyperinsulinemia directly affects bone structure independent of obesity and may explain, in part, the higher trabecular bone density and favorable trabecular microarchitecture seen in individuals with type 2 diabetes mellitus. PMID:27243136

  20. Functional Apparent Moduli (FAMs) as Predictors of Oral Implant Osseointegration Dynamics

    OpenAIRE

    Chang, Po-Chun; Seol, Yang-Jo; Kikuchi, Noboru; Goldstein, Steven A.; Giannobile, William V.

    2010-01-01

    At present, limited functional data exists regarding the application and use of biomechanical and imaging technologies for oral implant osseointegration assessment. The objective of this investigation was to determine the functional apparent moduli (FAMs) that could predict the dynamics of oral implant osseointegration. Using an in vivo dental implant osseous healing model, two FAMs, functional bone apparent modulus (FBAM) and composite tissue apparent modulus (FCAM), of the selected peri-imp...

  1. Bone quality analysis using X-ray microtomography and microfluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Sales, E.; Lima, I. [Nuclear Instrumentation Laboratory, PEN/COPPE/UFRJ, PO Box: 68509, 21.941-972, Rio de Janeiro (Brazil); Assis, J.T. de [Polytechnic Institute, DEMEC/UERJ (Brazil); Gomez, W. [Department of Electrical Engineering, Center of the National Polytechnic Institute (Mexico); Pereira, W.C.A. [Biomedical Engineering Program, COPPE/UFRJ, Rio de Janeiro (Brazil); Lopes, R.T., E-mail: ricardo@lin.ufrj.br [Nuclear Instrumentation Laboratory, PEN/COPPE/UFRJ, PO Box: 68509, 21.941-972, Rio de Janeiro (Brazil)

    2012-07-15

    Bone quality is an evaluation index often applied in order to interpret clinical observations made upon bone health, such as bone mineral density, micro and macro architecture, and mineral content. Conventional inspection techniques do not provide full information on trabecular bone quality. This study shows the high resolution potential and the non-destructive character of X-ray microtomography and microfluorescence upon the application of such techniques for evaluating bone quality. The mineral content assessment was performed by two-dimensional concentration mappings of calcium, zinc, and strontium. The results showed significant changes in bone morphology. - Highlights: Black-Right-Pointing-Pointer This study shows bone microarchitectural evaluation by X-ray microtomography and microfluorescence. Black-Right-Pointing-Pointer For this purpose, lumbar vertebrae of Wistar rats have been used as test subjects. Black-Right-Pointing-Pointer X-ray techniques proved to have an excellent perfomance in quantifying bone mineral content.

  2. Multiphoton gonioscopy to image the trabecular meshwork of porcine eyes

    Science.gov (United States)

    Masihzadeh, Omid; Ammar, David A.; Kahook, Malik Y.; Gibson, Emily A.; Lei, Tim C.

    2013-03-01

    The aqueous outflow system (AOS), including the trabecular meshwork (TM), the collector channels (CC) and the Schlemm's canal (SC), regulates intraocular pressure (IOP) through the drainage of the aqueous humor (AH). Abnormal IOP elevation leads to increased pressure stress to retinal ganglion cells, resulting in cell loss that can ultimately lead to complete loss of eyesight. Therefore, development of imaging tools to detect abnormal structural and functional changes of the AOS is important in early diagnosis and prevention of glaucoma. Multiphoton microscopy (MPM), including twophoton autofluorescence (TPAF) and second harmonic generation (SHG), is a label-free microscopic technique that allows molecular specific imaging of biological tissues like the TM. Since the TM and other AOS structures are located behind the highly scattering scleral tissue, transscleral imaging of the TM does not provide enough optical resolution. In this work, a gonioscopic lens is used to allow direct optical access of the TM through the cornea for MPM imaging. Compared to transscleral imaging, the acquired MPM images show improved resolution as individual collagen fiber bundles of the TM can be observed. MPM gonioscopy may have the potential to be developed as a future clinical imaging tool for glaucoma diagnostics.