Technique for bone volume measurement from human femur head samples by classification of micro-CT image histograms.

PubMed

Marinozzi, Franco; Bini, Fabiano; Marinozzi, Andrea; Zuppante, Francesca; De Paolis, Annalisa; Pecci, Raffaella; Bedini, Rossella

2013-01-01

Micro-CT analysis is a powerful technique for a non-invasive evaluation of the morphometric parameters of trabecular bone samples. This elaboration requires a previous binarization of the images. A problem which arises from the binarization process is the partial volume artifact. Voxels at the external surface of the sample can contain both bone and air so thresholding operates an incorrect estimation of volume occupied by the two materials. The aim of this study is the extraction of bone volumetric information directly from the image histograms, by fitting them with a suitable set of functions. Nineteen trabecular bone samples were extracted from femoral heads of eight patients subject to a hip arthroplasty surgery. Trabecular bone samples were acquired using micro-CT Scanner. Hystograms of the acquired images were computed and fitted by Gaussian-like functions accounting for: a) gray levels produced by the bone x-ray absorption, b) the portions of the image occupied by air and c) voxels that contain a mixture of bone and air. This latter contribution can be considered such as an estimation of the partial volume effect. The comparison of the proposed technique to the bone volumes measured by a reference instrument such as by a helium pycnometer show the method as a good way for an accurate bone volume calculation of trabecular bone samples.

Anterior iliac crest, posterior iliac crest, and proximal tibia donor sites: a comparison of cancellous bone volumes in fresh cadavers.

PubMed

Engelstad, Mark E; Morse, Timothy

2010-12-01

The anterior iliac crest, posterior iliac crest, and proximal tibia are common cancellous donor sites used for autogenous bone grafting. Donor site selection is partly dependent on the expected volume of available bone, but reports of cancellous bone volumes at each of these sites are variable. The goal of this study was to compare the volumes of cancellous bone harvested from donor sites within the same cadaver. Within each of 10 fresh frozen cadavers, cancellous bone was harvested from 3 donor sites-anterior iliac crest, posterior iliac crest, and proximal tibia-using established surgical techniques. Bone volumes were measured by fluid displacement. Mean compressed cancellous bone volumes from the 3 donor sites were compared among cadavers. Within each cadaver, the 3 donor sites were given a volume rank score from 1 (least volume) to 3 (most volume). Among cadavers, mean compressed cancellous bone volumes from the proximal tibia (11.3 mL) and posterior iliac crest (10.1 mL) were significantly greater than the anterior iliac crest (7.0 mL). Within cadavers, the mean volume rank score of the proximal tibia (mean rank, 2.7) was statistically greater than that for the posterior iliac crest (mean rank, 2.0), which was statistically greater than that for the anterior iliac crest (mean rank, 1.2). Strong correlations in bone volume existed between the proximal tibia and iliac crests (r = 0.67) and between the anterior iliac crest and posterior iliac crest (r = 0.93). The proximal tibia and posterior iliac crest yielded a significantly greater mean volume of compressed cancellous bone than the anterior iliac crest. Within individual cadaver skeletons, the proximal tibia was most likely to yield the largest cancellous volume, whereas the anterior iliac crest was most likely to yield the smallest cancellous volume. Although the proximal tibia contains relatively large volumes of cancellous bone, further investigation is required to determine how much cancellous bone can

Engineering clinically relevant volumes of vascularized bone

PubMed Central

Roux, Brianna M; Cheng, Ming-Huei; Brey, Eric M

2015-01-01

Vascularization remains one of the most important challenges that must be overcome for tissue engineering to be consistently implemented for reconstruction of large volume bone defects. An extensive vascular network is needed for transport of nutrients, waste and progenitor cells required for remodelling and repair. A variety of tissue engineering strategies have been investigated in an attempt to vascularize tissues, including those applying cells, soluble factor delivery strategies, novel design and optimization of bio-active materials, vascular assembly pre-implantation and surgical techniques. However, many of these strategies face substantial barriers that must be overcome prior to their ultimate translation into clinical application. In this review recent progress in engineering vascularized bone will be presented with an emphasis on clinical feasibility. PMID:25877690

Mapping Bone Mineral Density Obtained by Quantitative Computed Tomography to Bone Volume Fraction

NASA Technical Reports Server (NTRS)

Pennline, James A.; Mulugeta, Lealem

2017-01-01

Methods for relating or mapping estimates of volumetric Bone Mineral Density (vBMD) obtained by Quantitative Computed Tomography to Bone Volume Fraction (BVF) are outlined mathematically. The methods are based on definitions of bone properties, cited experimental studies and regression relations derived from them for trabecular bone in the proximal femur. Using an experimental range of values in the intertrochanteric region obtained from male and female human subjects, age 18 to 49, the BVF values calculated from four different methods were compared to the experimental average and numerical range. The BVF values computed from the conversion method used data from two sources. One source provided pre bed rest vBMD values in the intertrochanteric region from 24 bed rest subject who participated in a 70 day study. Another source contained preflight vBMD values from 18 astronauts who spent 4 to 6 months on the ISS. To aid the use of a mapping from BMD to BVF, the discussion includes how to formulate them for purpose of computational modeling. An application of the conversions would be used to aid in modeling of time varying changes in vBMD as it relates to changes in BVF via bone remodeling and/or modeling.

Efficacy of different bone volume expanders for augmenting lumbar fusions.

PubMed

Epstein, Nancy E

2008-01-01

A wide variety of bone volume expanders are being used in performing posterolateral lumbar noninstrumented and instrumented lumbar fusions. This article presents a review of their efficacy based on fusion rates, complications, and outcomes. Lumbar noninstrumented and instrumented fusions frequently use laminar autografts and different bone graft expanders. This review presents the utility of multiple forms/ratios of DBMs containing allografts. It also discusses the efficacy of artificial bone graft substitutes, including HA and B-TCP. Dynamic x-ray and/or CT examinations were used to document fusion in most series. Outcomes were variously assessed using Odom's criteria or different outcome questionnaires (Oswestry Questionnaire, SF-36, Dallas Pain Questionnaire, and/or Low Back Pain Rating Scale). Performing noninstrumented and instrumented lumbar posterolateral fusions resulted in comparable fusion rates in many series. Similar outcomes were also documented based on Odom's criteria or the multiple patient-based questionnaires. However, in some studies, the addition of spinal instrumentation increased the reoperation rate, operative time, blood loss, and cost. Various forms of DBMs, applied in different ratios to autografts, effectively supplemented spinal fusions in animal models and patient series. beta-Tricalcium phosphate, which is used to augment autograft fusions addressing idiopathic scoliosis or lumbar disease, also proved to be effective. Different types of bone volume expanders, including various forms of allograft-based DBMs, and artificial bone graft substitutes (HA and B-TCP) effectively promote posterolateral lumbar noninstrumented and instrumented fusions when added to autografts.

Computer-aided design evaluation of harvestable mandibular bone volume: a clinical and tomographic human study.

PubMed

Verdugo, Fernando; Simonian, Krikor; Raffaelli, Luca; D'Addona, Antonio

2014-06-01

To evaluate and compare the volume of bone graft material that can be safely harvested from the mandibular symphysis and rami using a computer-aided design (CAD) software program. Preoperative computerized tomography scans from 40 patients undergoing bone augmentation procedures were analyzed. Symphysis and rami cross sections were mapped using a CAD software program (AutoCAD(®), Autodesk, Inc., San Rafael, CA, USA) to evaluate the bone volume that can be safely harvested. CAD calculations were contrasted to intrasurgical measurements in a subgroup of 20 individuals. CAD calculations yielded a safe harvestable osseous volume of 1.44 cm(3) ± 0.49 for the symphysis and 0.82 cm(3) ± 0.21 for each ramus (p < .0001, confidence interval [CI] 95%: 0.47-0.78). These measurements were significantly lower (p < .0001) than the bone volumes harvested intrasurgically for both symphysis and ramus, respectively (2.40 cm(3) ± 0.50 vs. 2.65 cm(3) ± 0.45). CAD calculations of harvestable symphysis and ramus bone translated into an average of 2.40 cm(3) ± 0.50 (range: 1.80-3.10 cm(3)) and 2.65 cm(3) ± 0.45 (range: 1.90-3.50) of particulate bone graft intrasurgically, respectively. Ramus cortical was significantly thicker than the symphysis cortical, 2.9 ± 0.4 mm versus 2.19 mm ± 0.4 mm (p < .0001, CI 95%: 0.45-1.03). The symphysis and rami are good harvesting sources to obtain dense corticocancellous bone. The significant volumetric CAD differences between the symphysis and ramus seem to balance out intrasurgically and may be due to the greater cortical bone volume at the ramus area. It is plausible to harvest an average of 7.70 cm(3) from the symphysis and rami alone. The use of a CAD software program can enhance surgical treatment planning prior to bone transplantation. © 2012 Wiley Periodicals, Inc.

Intra-oral soft tissue expansion and volume stability of onlay bone grafts.

PubMed

Abrahamsson, Peter

2011-01-01

Insufficient regeneration of missing bone and soft-tissue may present aesthetic or functional problems in patients indicated for dental implant surgery. Several techniques such as bone grafts, bone substitutes and guided tissue regeneration (GTR) have been described to rebuild a compromised alveolar ridge. Adequate soft-tissue coverage of grafted bone and titanium-mesh is important to avoid exposure which may result in loss of the bone graft. The general aim of this thesis was to evaluate use of an osmotic tissue expander for expanding intra-oral soft tissue--creating a surplus of soft tissue-- in preparation for onlay bone grafting. An experimental rabbit model was used in studies (I), (II) and (III). In (I) an osmotic soft-tissue expander was placed bilaterally on the lateral wall of the mandible via an extra-oral approach. After two weeks of expansion the rabbits were killed and specimens were collected for histology. No inflammatory reaction and no resorbtion of the cortical bone occured. The periosteum was expanded and new bone formation was seen in the edges of the expander. In (II) and (III) the expander was placed under the periosteum in the same way as in (I): bilaterally in 13 rabbits in (II) and unilaterally in 11 rabbits in (III). After two weeks of expansion the expander was identified and removed. In (II) particulated bone was placed at the recipient site protected by a titanium mesh in one site and a bio-resorbable mesh on the other site. In (III), DBBM particles and bone particles collected from the lateral border of the mandible separated by a collagen membrane was placed at the recipient site. The graft was protected by a pre-bent titanium mesh covered by a collagen membrane. After a healing period of 3 months specimens were collected for histological and SEM examination. New bone was growing in direct contact with the titanium mesh and bio resorbable mesh. The newly formed bone had the same calcium content as the mature bone in the base of the

The influence of bone substitute materials on the bone volume after maxillary sinus augmentation: a microcomputerized tomography study.

PubMed

Kühl, Sebastian; Brochhausen, Christoph; Götz, Hermann; Filippi, Andreas; Payer, Michael; d'Hoedt, Bernd; Kreisler, Matthias

2013-03-01

This study aims to evaluate the effect of adding bone substitute materials (BSM) to particulated autogenous bone (PAB) on the volume fraction (Vf) of newly formed bone after maxillary sinus augmentation. Thirty healthy patients undergoing maxillary sinus augmentation were included. PAB (N = 10), mixtures of PAB and beta-tricalciumphosphate (PAB/β-TCP) (N = 10), as well as PAB and β-TCP and hydroxyapatite (PAB/HA/β-TCP) (N = 10) were randomly used for sinus augmentation. A sample of the graft material was maintained from each patient at time of maxillary sinus augmentation, and Vfs of the PAB and/or BSM in the samples were determined by means of microcomputerized tomography (μ-CT). Five months later, samples of the grafted areas were harvested during implantation using a trephine bur. μ-CT analysis of these samples was performed, and the Vf of bone and BSM were compared with the data obtained 5 months earlier from the original material. The mean Vf of the bone showed a statistically significant increase (p < 0.05) in all groups after a healing period of 5 months without statistically significant difference between the groups. With regard to the increase of bone volume, it is not relevant if PAB is used alone or combined with β-TCP or HA/β-TCP. The amount of PAB and associated donor site morbidity may be reduced by adding BSM for maxillary sinus augmentation.

Micro-computed tomography assessment of human alveolar bone: bone density and three-dimensional micro-architecture.

PubMed

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 < .05. A wide range of bone density was observed. There was a significant difference between the maxilla and mandible. All micro 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.

Engineering clinically relevant volumes of vascularized bone.

PubMed

Roux, Brianna M; Cheng, Ming-Huei; Brey, Eric M

2015-05-01

Vascularization remains one of the most important challenges that must be overcome for tissue engineering to be consistently implemented for reconstruction of large volume bone defects. An extensive vascular network is needed for transport of nutrients, waste and progenitor cells required for remodelling and repair. A variety of tissue engineering strategies have been investigated in an attempt to vascularize tissues, including those applying cells, soluble factor delivery strategies, novel design and optimization of bio-active materials, vascular assembly pre-implantation and surgical techniques. However, many of these strategies face substantial barriers that must be overcome prior to their ultimate translation into clinical application. In this review recent progress in engineering vascularized bone will be presented with an emphasis on clinical feasibility. © 2015 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Association of physical activity and physical performance with tibial cartilage volume and bone area in young adults.

PubMed

Antony, Benny; Venn, Alison; Cicuttini, Flavia; March, Lyn; Blizzard, Leigh; Dwyer, Terence; Cross, Marita; Jones, Graeme; Ding, Changhai

2015-10-26

Physical activity has been recommended to patients with knee osteoarthritis for improving their symptoms. However, it is still controversial if physical activity has effects on joint structures including cartilage volume. The aim of this study was to describe the associations between physical activity and performance measured 5 years prior and tibial cartilage volume and bone area in young adults. Subjects broadly representative of the Australian population (n = 328, aged 31-41 years, female 47.3 %) were selected from the Childhood Determinants of Adult Health study. They underwent T1-weighted fat-suppressed magnetic resonance imaging (MRI) scans of their knees. Tibial bone area and cartilage volume were measured from MRI. Physical activity (measured using long international physical activity questionnaire (IPAQ)) and performance measures (long jump, leg muscle strength, physical work capacity (PWC170)) were measured 5 years prior. In multivariable analyses, total physical activity (min/week) (β: 0.30 mm(3), 95 % CI: 0.13,0.47), vigorous (β: 0.54 mm(3), 95 % CI: 0.13,0.94), moderate (β: 0.34 mm(3), 95 % CI: 0.01,0.67), walking (β: 0.40 mm(3), 95 % CI: 0.07,0.72) and IPAQ category (β: 182.9 mm(3), 95 % CI: 51.8,314.0) were positively associated with total tibial cartilage volume but not tibial bone area. PWC170, long jump and leg muscle strength were positively and significantly associated with both total tibial cartilage volume and total tibial bone area; and the associations with tibial cartilage volume decreased in magnitude but remained significant for PWC170 and long jump after further adjustment for tibial bone area. While tibial bone area is affected only by physical performance, total tibial cartilage volume can be influenced by both physical activity and performance in younger adults. The clinical significance suggests a beneficial effect for cartilage but the bone area association was restricted to performance suggesting other factors

Adequate calcium intake during long periods improves bone mineral density in healthy children. Data from the Childhood Obesity Project.

PubMed

Closa-Monasterolo, Ricardo; Zaragoza-Jordana, Marta; Ferré, Natàlia; Luque, Veronica; Grote, Veit; Koletzko, Berthold; Verduci, Elvira; Vecchi, Fiammetta; Escribano, Joaquin

2018-06-01

Bone mineralization can be influenced by genetic factors, hormonal status, nutrition, physical activity and body composition. The association of higher calcium (Ca) intake or Ca supplementation with better bone mineral density (BMD) remains controversial. Furthermore, it has been speculated that maintaining long-term adequate Ca intake rather than having a brief supplementation period is more effective. The aim of the study was to prospectively analyse the influence of adequate Ca intake on BMD at 7 years of age in European children. Data from the Childhood Obesity Project were analysed in a prospective longitudinal cohort trial. Dietary intake was recorded using 3-day food records at 4, 5 and 6 years of age. The probability of adequate intake (PA) of Ca was calculated following the American Institute of Medicine guidelines for individual assessments, with FAO, WHO and United Nations University joint expert consultation dietary recommendations. Children were categorised as having high Ca PA (PA >95%) or not (PA <95%). At 7 years, whole body (WB) and lumbar spine (LS) BMD were measured in the Spanish subsample by dual-energy x-ray absorptiometry. Internal BMD z-scores were calculated; BMD below -1 z-score were considered to indicate osteopenia, and BMD z-scores below -2, "low bone mineral density for age". BMD was measured in 179 children. Ca intake at 6 years was positively correlated with LS BMD at 7 years (R = 0.205, p = 0.030). A Ca increase of 100 mg/day explained 19.4% (p = 0.011) of the LS BMD z-score variation, modifying it by 0.089 (0.021, 0.157) units. Children with Ca PA >95% at 5 and 6 or from 4 to 6 years of age showed higher BMD z-scores at the LS and WB levels than children with Ca PA <95% (p < 0.001 and p < 0.05 for LS and WB BMD, respectively). Ca PA >95% maintained over 2 years explained 26.3% of the LS BMD z-score variation (p < 0.001), increasing it by 0.669 (0.202, 1.137). PA >95% maintained over 3 years explained 24.9% of the LS

New bone formation in a bone defect associated to dental implant using absorbable or non-absorbable membrane in a dog model

PubMed Central

Lopez, Maria de Almeida; Olate, Sergio; Lanata-Flores, Antonio; Pozzer, Leandro; Cavalieri-Pereira, Lucas; Cantín, Mario; Vásquez, Bélgica; de Albergaria-Barbosa, José

2013-01-01

The aim of this research was to determine the bone formation capacity in fenestration defects associated with dental implants using absorbable and non-absorbable membranes. Six dogs were used in the study. In both tibias of each animal 3 implants were installed, and around these 5 mm circular defects were created. The defects were covered with absorbable membranes (experimental group 1), non-absorbable membranes (experimental group 2), and the third defect was not covered (control group). At 3 and 8 weeks post-surgery, the animals were euthanized and the membranes with the bone tissue around the implants were processed for histological analysis. The statistical analysis was conducted with Tukey’s test, considering statistical significance when p<0.1. Adequate bone repair was observed in the membrane-covered defects. At 3 weeks, organization of the tissue, bone formation from the periphery of the defect and the absence of inflammatory infiltrate were observed in both experimental groups, but the defect covered with absorbable membrane presented statistically greater bone formation. At 8 weeks, both membrane-covered defects showed adequate bone formation without significant differences, although they did in fact present differences with the control defect in both periods (p>0.1). In the defects without membrane, continuous connective tissue invasions and bone repair deficiency were observed. There were no significant differences in the characteristics and volume of the neoformed bone in the defects around the implants covered by the different membranes, whereas the control defects produced significantly less bone. The use of biological membranes contributes to bone formation in three-wall defects. PMID:24228090

A novel bone scraper for intraoral harvesting: a device for filling small bone defects.

PubMed

Zaffe, Davide; D'Avenia, Ferdinando

2007-08-01

To evaluate histologically the morphology and characteristics of bone chips harvested intraorally by Safescraper, a specially designed cortical bone collector. Bone chips harvested near a bone defect or in other intraoral sites were grafted into a post-extractive socket or applied in procedures for maxillary sinus floor augmentation or guided bone regeneration. Core biopsies were performed at implant insertion. Undecalcified specimens embedded in PMMA were studied by histology, histochemistry and SEM. Intraoral harvesting by Safescraper provided a simple, clinically effective regenerative procedure with low morbidity for collecting cortical bone chips (0.9-1.7 mm in length, roughly 100 microm thick). Chips had an oblong or quadrangular shape and contained live osteocytes (mean viability: 45-72%). Bone chip grafting produced newly formed bone tissue suitable for implant insertion. Trabecular bone volume measured on biopsies decreased with time (from 45-55% to 23%). Grafted chips made up 50% or less of the calcified tissue in biopsies. Biopsies presented remodeling activities, new bone formation by apposition and live osteocytes (35% or higher). In conclusion, Safescraper is capable of collecting adequate amounts of cortical bone chips from different intraoral sites. The procedure is effective for treating alveolar defects for endosseous implant insertion and provides good healing of small bone defects after grafting with bone chips. The study indicates that Safescraper is a very useful device for in-office bone harvesting procedures in routine peri-implant bone regeneration.

Fluid volume displacement at the oval and round windows with air and bone conduction stimulation

NASA Astrophysics Data System (ADS)

Stenfelt, Stefan; Hato, Naohito; Goode, Richard L.

2004-02-01

The fluids in the cochlea are normally considered incompressible, and the fluid volume displacement of the oval window (OW) and the round window (RW) should be equal and of opposite phase. However, other channels, such as the cochlear and vestibular aqueducts, may affect the fluid flow. To test if the OW and RW fluid flows are equal and of opposite phase, the volume displacement was assessed by multiple point measurement at the windows with a laser Doppler vibrometer. This was done during air conduction (AC) stimulation in seven fresh human temporal bones, and with bone conduction (BC) stimulation in eight temporal bones and one human cadaver head. With AC stimulation, the average volume displacement of the two windows is within 3 dB, and the phase difference is close to 180° for the frequency range 0.1 to 10 kHz. With BC stimulation, the average volume displacement difference between the two windows is greater: below 2 kHz, the volume displacement at the RW is 5 to 15 dB greater than at the OW and above 2 kHz more fluid is displaced at the OW. With BC stimulation, lesions at the OW caused only minor changes of the fluid flow at the RW.

Fluid volume displacement at the oval and round windows with air and bone conduction stimulation.

PubMed

Stenfelt, Stefan; Hato, Naohito; Goode, Richard L

2004-02-01

The fluids in the cochlea are normally considered incompressible, and the fluid volume displacement of the oval window (OW) and the round window (RW) should be equal and of opposite phase. However, other channels, such as the cochlear and vestibular aqueducts, may affect the fluid flow. To test if the OW and RW fluid flows are equal and of opposite phase, the volume displacement was assessed by multiple point measurement at the windows with a laser Doppler vibrometer. This was done during air conduction (AC) stimulation in seven fresh human temporal bones, and with bone conduction (BC) stimulation in eight temporal bones and one human cadaver head. With AC stimulation, the average volume displacement of the two windows is within 3 dB, and the phase difference is close to 180 degrees for the frequency range 0.1 to 10 kHz. With BC stimulation, the average volume displacement difference between the two windows is greater: below 2 kHz, the volume displacement at the RW is 5 to 15 dB greater than at the OW and above 2 kHz more fluid is displaced at the OW. With BC stimulation, lesions at the OW caused only minor changes of the fluid flow at the RW.

Influence of Chromium-Cobalt-Molybdenum Alloy (ASTM F75) on Bone Ingrowth in an Experimental Animal Model.

PubMed

Zuchuat, Jésica; Berli, Marcelo; Maldonado, Ysaí; Decco, Oscar

2017-12-26

Cr-Co-Mo (ASTM F75) alloy has been used in the medical environment, but its use as a rigid barrier membrane for supporting bone augmentation therapies has not been extensively investigated. In the present study, Cr-Co-Mo membranes of different heights were placed in New Zealand white, male rabbit tibiae to assess the quality and volume of new bone formation, without the use of additional factors. Animals were euthanized at 20, 30, 40, and 60 days. Bone formation was observed in all of the cases, although the tibiae implanted with the standard membranes reached an augmentation of bone volume that agreed with the density values over the timecourse. In all cases, plasmatic exudate was found under the membrane and in contact with the new bone. Histological analysis indicated the presence of a large number of chondroblasts adjacent to the inner membrane surface in the first stages, and osteoblasts and osteocytes were observed under them. The bone formation was appositional. The Cr-Co-Mo alloy provides a scaffold with an adequate microenvironment for vertical bone volume augmentation, and the physical dimensions and disposition of the membrane itself influence the new bone formation.

Influence of Chromium-Cobalt-Molybdenum Alloy (ASTM F75) on Bone Ingrowth in an Experimental Animal Model

PubMed Central

Zuchuat, Jésica; Berli, Marcelo; Maldonado, Ysaí; Decco, Oscar

2017-01-01

Cr-Co-Mo (ASTM F75) alloy has been used in the medical environment, but its use as a rigid barrier membrane for supporting bone augmentation therapies has not been extensively investigated. In the present study, Cr-Co-Mo membranes of different heights were placed in New Zealand white, male rabbit tibiae to assess the quality and volume of new bone formation, without the use of additional factors. Animals were euthanized at 20, 30, 40, and 60 days. Bone formation was observed in all of the cases, although the tibiae implanted with the standard membranes reached an augmentation of bone volume that agreed with the density values over the timecourse. In all cases, plasmatic exudate was found under the membrane and in contact with the new bone. Histological analysis indicated the presence of a large number of chondroblasts adjacent to the inner membrane surface in the first stages, and osteoblasts and osteocytes were observed under them. The bone formation was appositional. The Cr-Co-Mo alloy provides a scaffold with an adequate microenvironment for vertical bone volume augmentation, and the physical dimensions and disposition of the membrane itself influence the new bone formation. PMID:29278372

Erythropoietic bone marrow in the pigeon: Development of its distribution and volume during growth and pneumatization of bones

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schepelmann, K.

1990-01-01

During postnatal development of the pigeon, a large portion of the skeleton becomes pneumatized, displacing the hemopoietic bone marrow. The consequences of pneumatization on distribution and quantity of bone marrow as well as the availability of other sites for hemopoiesis have been investigated. Hemopoietic marrow of differently aged pigeons divided into five groups from 1 week posthatching (p.h.) up to 6 months p.h. was labeled with Fe-59 and examined by serial whole-body sections. Autoradiography and morphometry as well as scintillation counts of single bones and organs were also carried out. No sign of a reactivation of embryonic sites of erythropoiesismore » was found. Bone marrow weight and its proportion of whole-body weight increased during the first 4 weeks p.h. from 0.54% to 2.44% and decreased in the following months to about 1.0%. The developing bone marrow showed a progressive distribution during the first months of life, eventually being distributed proportionally over the entire skeleton, except for the skull. At the age of 6 months p.h. bone marrow had been displaced, its volume decreasing in correlation to increasing pneumaticity and conversion to fatty marrow. This generates the characteristic pattern of bone marrow distribution in adult pigeons, which shows hemopoietic bone marrow in ulna, radius, femur, tibiotarsus, scapula, furcula, and the caudal vertebrae.« less

Lactation-Induced Changes in the Volume of Osteocyte Lacunar-Canalicular Space Alter Mechanical Properties in Cortical Bone Tissue.

PubMed

Kaya, Serra; Basta-Pljakic, Jelena; Seref-Ferlengez, Zeynep; Majeska, Robert J; Cardoso, Luis; Bromage, Timothy G; Zhang, Qihong; Flach, Carol R; Mendelsohn, Richard; Yakar, Shoshana; Fritton, Susannah P; Schaffler, Mitchell B

2017-04-01

Osteocytes can remove and remodel small amounts of their surrounding bone matrix through osteocytic osteolysis, which results in increased volume occupied by lacunar and canalicular space (LCS). It is well established that cortical bone stiffness and strength are strongly and inversely correlated with vascular porosity, but whether changes in LCS volume caused by osteocytic osteolysis are large enough to affect bone mechanical properties is not known. In the current studies we tested the hypotheses that (1) lactation and postlactation recovery in mice alter the elastic modulus of bone tissue, and (2) such local changes in mechanical properties are related predominantly to alterations in lacunar and canalicular volume rather than bone matrix composition. Mechanical testing was performed using microindentation to measure modulus in regions containing solely osteocytes and no vascular porosity. Lactation caused a significant (∼13%) reduction in bone tissue-level elastic modulus (p < 0.001). After 1 week postweaning (recovery), bone modulus levels returned to control levels and did not change further after 4 weeks of recovery. LCS porosity tracked inversely with changes in cortical bone modulus. Lacunar and canalicular void space increased 7% and 15% with lactation, respectively (p < 0.05), then returned to control levels at 1 week after weaning. Neither bone mineralization (assessed by high-resolution backscattered scanning electron microscopy) nor mineral/matrix ratio or crystallinity (assessed by Raman microspectroscopy) changed with lactation. Thus, changes in bone mechanical properties induced by lactation and recovery appear to depend predominantly on changes in osteocyte LCS dimensions. Moreover, this study demonstrates that tissue-level cortical bone mechanical properties are rapidly and reversibly modulated by osteocytes in response to physiological challenge. These data point to a hitherto unappreciated role for osteocytes in modulating and

Synthetic Parathyroid Hormone May Augment Bone Volume in Autogenous Grafts: A Study in Rats.

PubMed

dos Santos, Rodrigo A B; Ferreira, Marcelo S; Mafra, Carlos Eduardo S; Holzhausen, Marinella; de Lima, Luiz Antônio Pugliesi Alves; Mendes Pannuti, Cláudio; César Neto, João Batista

2016-01-01

Synthetic parathyroid hormone [PTH(1-34)] has been investigated for its benefits on bone healing and osteoporosis treatment; however, there is little information regarding bone grafts. This study therefore investigates the effect of PTH(1-34) on autogenous bone graft healing. Bone grafts were harvested from the calvarium of rats with a trephine bur (3-mm internal diameter) and placed on the cortex near the mandible angle with a titanium screw. Animals were randomly assigned to group 1 (control): subcutaneous injections of saline solution, three times a week (n = 15); group 2: 2 μg/kg PTH(1-34), three times a week (n = 15); and group 3: 40 μg/kg PTH(1-34), three times a week (n = 15). Thirty days postoperatively, the animals were killed, and specimens (implant + bed + graft) were removed and used for undecalcified sections. The following histometric parameters were evaluated: total bone thickness (TT) (bed + gap + graft), graft thickness (GT) (adjacent to the implant), bone-to-implant contact (BIC), and bone area (BA) (within the limits of the threads). Five additional animals were sacrificed immediately after surgery (zero hour) to register bed and graft sizes before healing. Group 3 showed significantly greater bone gain compared with groups 1 and 2 (TT and GT, P <0.05). In relation to initial thickness (zero hour), groups 1 and 2 showed a total decrease in volume of 15.91% and 20.83%, respectively, whereas group 3 showed a slight bone gain (1.21%). Data analysis revealed a significant difference for group 3 compared with groups 1 and 2 (P <0.01). No differences were observed for BIC and BA (P >0.05). Systemic administration of PTH(1-34) augmented bone volume in autogenous grafts.

Volume changes of autogenous bone after sinus lifting and grafting procedures: a 6-year computerized tomographic follow-up.

PubMed

Sbordone, Carolina; Toti, Paolo; Guidetti, Franco; Califano, Luigi; Bufo, Pantaleo; Sbordone, Ludovico

2013-04-01

To evaluate long-term bone remodelling of autografts over time (annually, for 6 years), comparing the block and particulate bone procedures for sinus floor elevation, as well as to evaluate the survival of positioned dental implants. Twenty-three sinus lift procedures with autogenous bone were performed: seven sinus lift procedures using particulate graft and 10 with block autogenous bone were performed in 17 patients. Employing a software program, pre- and post-surgical computerized tomography (CT) scans were used to compare the volume (V) and density (D) of inlay grafts over time (up to 6 years), and to determine the percentage of remaining bone (%R). All variable (V, D and %R) measurements were then compared statistically. At the 6-year survey for block form, a resorption of 21.5% was seen, whereas for particulate grafts there was a resorption of 39.2%. Both groups exhibited bone remodelling between the first and second follow-up which was significant regarding volume for the block form and regarding density for the particulate group. During the initial period of healing, the cortico-cancellous block bone grafted into the maxillary sinus underwent a negative remodelling of the volume, which is most probably due to graft cortex resorption, coupled with, primarily, an increase in density in the spongious area; for the particulate grafts, significant augmentations in density were obtained. The lack of significant differences among volumes was due to the wide degree of dispersion of the data. The rough data presented in this paper seem to support the use of a bone-block grafting procedure in maxillary sinus augmentation. Copyright © 2012 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Changes in nasal volume after surgically assisted bone-borne rapid maxillary expansion.

PubMed

Deeb, Wayel; Hansen, Lars; Hotan, Thorsten; Hietschold, Volker; Harzer, Winfried; Tausche, Eve

2010-06-01

The purposes of this study were to detect, locate, and examine the changes in transverse nasal width, area, and volume from bone-borne, surgically assisted rapid maxillary expansion (SARME) with the Dresden distractor by using computer tomography (CT). Sixteen patients (average age, 28.7 years) underwent axial CT scanning before and 6 months after SARME. They also underwent CT fusion on specific bony structures. The nasal bone width was examined in the coronal plane. The cross-sectional images of the nasal cavity were taken of the area surrounding the apertura piriformis, the choanae, and in between. We calculated cross-sectional areas and nasal volume according to these data. All but 2 patients had an increase in nasal volume of at least 5.1% (SD, 4.6%). The largest value of 35.3% (SD, 45.8%) was measured anteriorly on the nasal floor, decreasing cranially and posteriorly. This correlated with the V-shaped opening of the sutura palatina. There was no significant correlation between increase in nasal volume and transversal expansion. Because most of the air we breathe passes over the lower nasal floor, SARME is likely to improve nasal breathing. 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Marrow Adipose Tissue in Older Men: Association with Visceral and Subcutaneous Fat, Bone Volume, Metabolism, and Inflammation.

PubMed

Bani Hassan, Ebrahim; Demontiero, Oddom; Vogrin, Sara; Ng, Alvin; Duque, Gustavo

2018-03-26

Marrow (MAT) and subcutaneous (SAT) adipose tissues display different metabolic profiles and varying associations with aging, bone density, and fracture risk. Using a non-invasive imaging methodology, we aimed to investigate the associations between MAT, SAT, and visceral fat (VAT) with bone volume, bone remodeling markers, insulin resistance, and circulating inflammatory mediators in a population of older men. In this cross-sectional study, 96 healthy men (mean age 67 ± 5.5) were assessed for anthropometric parameters, body composition, serum biochemistry, and inflammatory panel. Using single-energy computed tomography images, MAT (in L2 and L3 and both hips), VAT, and SAT (at the level of L2-L3 and L4-L5) were measured employing Slice-O-Matic software (Tomovision), which enables specific tissue demarcation applying previously reported Hounsfield unit thresholds. MAT volume was similar in all anatomical sites and independent of BMI. In all femoral regions of interest (ROIs) there was a strong negative association between bone and MAT volumes (r = - 0.840 to - 0.972, p < 0.001), with location-dependent variations in the lumbar spine. Unlike VAT and SAT, no associations between MAT and serum glucose, inflammatory markers or insulin resistance indicators were found. Bone decline occurred without red marrow expansion; thus lost bone was mainly (if not exclusively) replaced by MAT. In conclusion, strong inverse correlations between MAT and bone mass, which have been previously observed in women, were also confirmed in older men. However, MAT volume in all ROIs was interrelated and unlike women, mainly independent of VAT or SAT. The lack of strong association between MAT vs VAT/SAT, and its discordant associations with metabolic and inflammatory mediators provide further evidence on MAT's distinct attributes in older men.

Effect of a Particulate and a Putty-Like Tricalcium Phosphate-Based Bone-grafting Material on Bone Formation, Volume Stability and Osteogenic Marker Expression after Bilateral Sinus Floor Augmentation in Humans

PubMed Central

Knabe, Christine; Adel Khattab, Doaa; Kluk, Esther; Struck, Rainer; Stiller, Michael

2017-01-01

This study examines the effect of a hyaluronic acid (HyAc) containing tricalcium phosphate putty scaffold material (TCP-P) and of a particulate tricalcium phosphate (TCP-G) graft on bone formation, volume stability and osteogenic marker expression in biopsies sampled 6 months after bilateral sinus floor augmentation (SFA) in 7 patients applying a split-mouth design. 10% autogenous bone chips were added to the grafting material during surgery. The grain size of the TCP granules was 700 to 1400 µm for TCP-G and 125 to 250 µm and 500 to 700 µm (ratio 1:1) for TCP-P. Biopsies were processed for immunohistochemical analysis of resin-embedded sections. Sections were stained for collagen type I (Col I), alkaline phosphatase (ALP), osteocalcin (OC) and bone sialoprotein (BSP). Furthermore, the bone area and biomaterial area fraction were determined histomorphometrically. Cone-beam CT data recorded after SFA and 6 months later were used for calculating the graft volume at these two time points. TCP-P displayed more advantageous surgical handling properties and a significantly greater bone area fraction and smaller biomaterial area fraction. This was accompanied by significantly greater expression of Col I and BSP and in osteoblasts and osteoid and a less pronounced reduction in grafting volume with TCP-P. SFA using both types of materials resulted in formation of sufficient bone volume for facilitating stable dental implant placement with all dental implants having been in function without any complications for 6 years. Since TCP-P displayed superior surgical handling properties and greater bone formation than TCP-G, without the HyAc hydrogel matrix having any adverse effect on bone formation or graft volume stability, TCP-P can be regarded as excellent grafting material for SFA in a clinical setting. The greater bone formation observed with TCP-P may be related to the difference in grain size of the TCP granules and/or the addition of the HyAc. PMID:28758916

The Long-Term Clinical Outcomes Following Autogenous Bone Grafting for Large-Volume Defects of the Knee

PubMed Central

Delano, Mark; Spector, Myron; Pittsley, Andrew; Gottschalk, Alexander

2014-01-01

Objective: We report the long-term clinical outcomes of patients who underwent autogenous bone grafting of large-volume osteochondral defects of the knee due to osteochondritis dessicans (OCD) and osteonecrosis (ON). This is the companion report to one previous published on the biological response. We hypothesized that these grafts would integrate with host bone and the articular surface would form fibrocartilage providing an enduring clinical benefit. Design: Three groups (patients/knees) were studied: OCD without a fragment (n = 12/13), OCD with a partial fragment (n = 14/16), and ON (n = 25/26). Twenty-five of 52 patients were available for clinical follow-up between 12 and 21 years. Electronic medical records provided comparison clinical information. In addition, there were plain film radiographs, MRIs, plus repeat arthroscopy and biopsy on 14 patients. Results: Autogenous bone grafts integrated with the host bone. MRI showed soft tissue covering all the grafts at long-term follow-up. Biopsy showed initial surface fibrocartilage that subsequently converted to fibrocartilage and hyaline cartilage at 20 years. OCD patients had better clinical outcomes than ON patients. No OCD patients were asymptomatic at anytime following surgery. Half of the ON patients came to total knee replacement within 10 years. Conclusions: Autogenous bone grafting provides an alternative biological matrix to fill large-volume defects in the knee as a singular solution integrating with host bone and providing an enduring articular cartilage surface. The procedure is best suited for those with OCD. The treatment for large-volume articular defects by this method remains salvage in nature and palliative in outcome. PMID:26069688

Sex determination using discriminant analysis of upper and lower extremity bones: New approach using the volume and surface area of digital model.

PubMed

Lee, U-Young; Kim, In-Beom; Kwak, Dai-Soon

2015-08-01

This study used 110 CT images taken from donated Korean cadavers to create 3-D models of the following upper and lower limb bones: the clavicle, scapula, humerus, radius, ulna, hip bone (os coxa), femur, patella (knee cap), tibia, talus, and calcaneus. In addition, the bone volume and surface area were calculated to determine sex differences using discriminant analysis. Significant sex differences were found in all bones with respect to volume and surface area (p<0.01). The order of volume was the same in females and males (femur>hip bone>tibia>humerus>scapula), although the order of surface area was different. The largest surface area in men was the femur and in women was the hip bone (p<0.01). An interesting finding of this study was that the ulna is the bone with the highest accuracy for sex determination (94%). When using the surface area of multiple bones, the maximum accuracy (99.4%) was achieved. The equation was as follows: (discriminant equation of surface area; female<0bone+0.091×patella+(-0.052)×fibula+0.043×talus-11.548. These results show that bone volume and surface area of extremity bones can be used for sex determination. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Assessing bone volume for orthodontic miniplate fixation below the maxillary frontal process.

PubMed

Präger, T M; Brochhagen, H G; Mischkowski, R; Jost-Brinkmann, P-G; Müller-Hartwich, R

2014-09-01

The maxillary bone below the frontal process is used for orthodontic anchorage; indications have included skeletally anchored protraction of the maxilla for treating Class III malocclusions or the intrusion of teeth in patients with a deep bite. This study was conducted to assess the condition of bone before cortically implanting miniplates in that area of the maxilla. A total of 51 thin-sliced computed tomography scans of 51 fully-dentate adult patients (mean age 24.0 ± 8.1 years; 27 men and 24 women) obtained prior to third-molar osteotomy were evaluated. Study parameters included total bone thickness, thickness of the facial cortical plate, and width of the nasal maxillary buttress. All these parameters were measured at different vertical levels. The bone volume adjacent to the piriform aperture was most pronounced at the basal level and decreased progressively toward more cranial levels. The basal bone structure had a mean total thickness of 7.8 mm, facial cortical plate thickness of 1.9 mm, and nasal maxillary buttress width of 9.2 mm. At 16 mm cranial to the aperture base, these values fell to 5.6 mm, 1.3 mm, and 5.8 mm, respectively. These bone measurements suggest that screws 7 mm in length can be inserted at the base level of the piriform aperture and screws 5 mm long at the cranial end of the bone.

One-month spaceflight compromises the bone microstructure, tissue-level mechanical properties, osteocyte survival and lacunae volume in mature mice skeletons.

PubMed

Gerbaix, Maude; Gnyubkin, Vasily; Farlay, Delphine; Olivier, Cécile; Ammann, Patrick; Courbon, Guillaume; Laroche, Norbert; Genthial, Rachel; Follet, Hélène; Peyrin, Françoise; Shenkman, Boris; Gauquelin-Koch, Guillemette; Vico, Laurence

2017-06-01

The weightless environment during spaceflight induces site-specific bone loss. The 30-day Bion-M1 mission offered a unique opportunity to characterize the skeletal changes after spaceflight and an 8-day recovery period in mature male C57/BL6 mice. In the femur metaphysis, spaceflight decreased the trabecular bone volume (-64% vs. Habitat Control), dramatically increased the bone resorption (+140% vs. Habitat Control) and induced marrow adiposity invasion. At the diaphysis, cortical thinning associated with periosteal resorption was observed. In the Flight animal group, the osteocyte lacunae displayed a reduced volume and a more spherical shape (synchrotron radiation analyses), and empty lacunae were highly increased (+344% vs. Habitat Control). Tissue-level mechanical cortical properties (i.e., hardness and modulus) were locally decreased by spaceflight, whereas the mineral characteristics and collagen maturity were unaffected. In the vertebrae, spaceflight decreased the overall bone volume and altered the modulus in the periphery of the trabecular struts. Despite normalized osteoclastic activity and an increased osteoblast number, bone recovery was not observed 8 days after landing. In conclusion, spaceflight induces osteocyte death, which may trigger bone resorption and result in bone mass and microstructural deterioration. Moreover, osteocyte cell death, lacunae mineralization and fatty marrow, which are hallmarks of ageing, may impede tissue maintenance and repair.

Combination of bone morphogenetic protein-2 plasmid DNA with chemokine CXCL12 creates an additive effect on bone formation onset and volume.

PubMed

Wegman, F; Poldervaart, M T; van der Helm, Y J; Oner, F C; Dhert, W J; Alblas, J

2015-07-27

Bone morphogenetic protein-2 (BMP-2) gene delivery has shown to induce bone formation in vivo in cell-based tissue engineering. In addition, the chemoattractant stromal cell-derived factor-1α (SDF-1α, also known as CXCL12) is known to recruit multipotent stromal cells towards its release site where it enhances vascularisation and possibly contributes to osteogenic differentiation. To investigate potential cooperative behaviour for bone formation, we investigated combined release of BMP-2 and SDF-1α on ectopic bone formation in mice. Multipotent stromal cell-seeded and cell-free constructs with BMP-2 plasmid DNA and /or SDF-1α loaded onto gelatin microparticles, were implanted subcutaneously in mice for a period of 6 weeks. Histological analysis and histomorphometry revealed that the onset of bone formation and the formed bone volume were both enhanced by the combination of BMP-2 and SDF-1α compared to controls in cell-seeded constructs. Samples without seeded multipotent stromal cells failed to induce any bone formation. We conclude that the addition of stromal cell-derived factor-1α to a cell-seeded alginate based bone morphogenetic protein-2 plasmid DNA construct has an additive effect on bone formation and can be considered a promising combination for bone regeneration.

[Morphological analysis of bone dynamics and metabolic bone disease. Effect of loading on bone tissue].

PubMed

Sakai, Akinori

2011-04-01

We developed a voluntarily climbing animal model to investigate the effect of skeletal loading on bone tissue. At the cross section of the mid-femur, climbing exercise increases outer diameter and area of cortical bone. The mechanical strength of the femur is increased. This change of cortical volume and structure is more marked in anti-gravity exercise, such as climbing and jumping, than aerobic exercise. At the bone marrow area, climbing exercise increases trabecular bone volume and osteoblast number, while it decreases fat volume and adipocyte number. Skeletal loading promotes differentiation from mesenchymal stem cells to osteoblasts and suppresses that to adipocytes by facilitating the signal through PTH÷PTHrP receptor.

Experimental flat-panel high-spatial-resolution volume CT of the temporal bone.

PubMed

Gupta, Rajiv; Bartling, Soenke H; Basu, Samit K; Ross, William R; Becker, Hartmut; Pfoh, Armin; Brady, Thomas; Curtin, Hugh D

2004-09-01

A CT scanner employing a digital flat-panel detector is capable of very high spatial resolution as compared with a multi-section CT (MSCT) scanner. Our purpose was to determine how well a prototypical volume CT (VCT) scanner with a flat-panel detector system defines fine structures in temporal bone. Four partially manipulated temporal-bone specimens were imaged by use of a prototypical cone-beam VCT scanner with a flat-panel detector system at an isometric resolution of 150 microm at the isocenter. These specimens were also depicted by state-of-the-art multisection CT (MSCT). Forty-two structures imaged by both scanners were qualitatively assessed and rated, and scores assigned to VCT findings were compared with those of MSCT. Qualitative assessment of anatomic structures, lesions, cochlear implants, and middle-ear hearing aids indicated that image quality was significantly better with VCT (P < .001). Structures near the spatial-resolution limit of MSCT (e.g., bony covering of the tympanic segment of the facial canal, the incudo-stapedial joint, the proximal vestibular aqueduct, the interscalar septum, and the modiolus) had higher contrast and less partial-volume effect with VCT. The flat-panel prototype provides better definition of fine osseous structures of temporal bone than that of currently available MSCT scanners. This study provides impetus for further research in increasing spatial resolution beyond that offered by the current state-of-the-art scanners.

Multi-temporal MRI carpal bone volumes analysis by principal axes registration

NASA Astrophysics Data System (ADS)

Ferretti, Roberta; Dellepiane, Silvana

2016-03-01

In this paper, a principal axes registration technique is presented, with the relevant application to segmented volumes. The purpose of the proposed registration is to compare multi-temporal volumes of carpal bones from Magnetic Resonance Imaging (MRI) acquisitions. Starting from the study of the second-order moment matrix, the eigenvectors are calculated to allow the rotation of volumes with respect to reference axes. Then the volumes are spatially translated to become perfectly overlapped. A quantitative evaluation of the results obtained is carried out by computing classical indices from the confusion matrix, which depict similarity measures between the volumes of the same organ as extracted from MRI acquisitions executed at different moments. Within the medical field, the way a registration can be used to compare multi-temporal images is of great interest, since it provides the physician with a tool which allows a visual monitoring of a disease evolution. The segmentation method used herein is based on the graph theory and is a robust, unsupervised and parameters independent method. Patients affected by rheumatic diseases have been considered.

Growth hormone and bone health.

PubMed

Bex, Marie; Bouillon, Roger

2003-01-01

Growth hormone (GH) and insulin-like growth factor-I have major effects on growth plate chondrocytes and all bone cells. Untreated childhood-onset GH deficiency (GHD) markedly impairs linear growth as well as three-dimensional bone size. Adult peak bone mass is therefore about 50% that of adults with normal height. This is mainly an effect on bone volume, whereas true bone mineral density (BMD; g/cm(3)) is virtually normal, as demonstrated in a large cohort of untreated Russian adults with childhood-onset GHD. The prevalence of fractures in these untreated childhood-onset GHD adults was, however, markedly and significantly increased in comparison with normal Russian adults. This clearly indicates that bone mass and bone size matter more than true bone density. Adequate treatment with GH can largely correct bone size and in several studies also bone mass, but it usually requires more than 5 years of continuous treatment. Adult-onset GHD decreases bone turnover and results in a mild deficit, generally between -0.5 and -1.0 z-score, in bone mineral content and BMD of the lumbar spine, radius and femoral neck. Cross-sectional surveys and the KIMS data suggest an increased incidence of fractures. GH replacement therapy increases bone turnover. The three controlled studies with follow-up periods of 18 and 24 months demonstrated a modest increase in BMD of the lumbar spine and femoral neck in male adults with adult-onset GHD, whereas no significant changes in BMD were observed in women. GHD, whether childhood- or adult-onset, impairs bone mass and strength. Appropriate substitution therapy can largely correct these deficiencies if given over a prolonged period. GH therapy for other bone disorders not associated with primary GHD needs further study but may well be beneficial because of its positive effects on the bone remodelling cycle. Copyright 2003 S. Karger AG, Basel

[Comparative study on graft of autogeneic iliac bone and tissue engineered bone].

PubMed

Shen, Bing; Xie, Fu-lin; Xie, Qing-fang

2002-11-01

To compare the clinical results of repairing bone defect of limbs with tissue engineering technique and with autogeneic iliac bone graft. From July 1999 to September 2001, 52 cases of bone fracture were randomly divided into two groups (group A and B). Open reduction and internal fixation were performed in all cases as routine operation technique. Autogeneic iliac bone was implanted in group A, while tissue engineered bone was implanted in group B. Routine postoperative treatment in orthopedic surgery was taken. The operation time, bleeding volume, wound healing and drainage volume were compared. The bone union was observed by the X-ray 1, 2, 3, and 5 months after operation. The sex, age and disease type had no obvious difference between groups A and B. all the wounds healed with first intention. The swelling degree of wound and drainage volume had no obvious difference. The operation time in group A was longer than that in group B (25 minutes on average) and bleeding volume in group A was larger than that in group B (150 ml on average). Bone union completed within 3 to 7 months in both groups. But there were 2 cases of delayed union in group A and 1 case in group B. Repair of bone defect with tissue engineered bone has as good clinical results as that with autogeneic iliac bone graft. In aspect of operation time and bleeding volume, tissue engineered bone graft is superior to autogeneic iliac bone.

Solid volume fraction estimation of bone:marrow replica models using ultrasound transit time spectroscopy.

PubMed

Wille, Marie-Luise; Langton, Christian M

2016-02-01

The acceptance of broadband ultrasound attenuation (BUA) for the assessment of osteoporosis suffers from a limited understanding of both ultrasound wave propagation through cancellous bone and its exact dependence upon the material and structural properties. It has recently been proposed that ultrasound wave propagation in cancellous bone may be described by a concept of parallel sonic rays; the transit time of each ray defined by the proportion of bone and marrow propagated. A Transit Time Spectrum (TTS) describes the proportion of sonic rays having a particular transit time, effectively describing the lateral inhomogeneity of transit times over the surface aperture of the receive ultrasound transducer. The aim of this study was to test the hypothesis that the solid volume fraction (SVF) of simplified bone:marrow replica models may be reliably estimated from the corresponding ultrasound transit time spectrum. Transit time spectra were derived via digital deconvolution of the experimentally measured input and output ultrasonic signals, and compared to predicted TTS based on the parallel sonic ray concept, demonstrating agreement in both position and amplitude of spectral peaks. Solid volume fraction was calculated from the TTS; agreement between true (geometric calculation) with predicted (computer simulation) and experimentally-derived values were R(2)=99.9% and R(2)=97.3% respectively. It is therefore envisaged that ultrasound transit time spectroscopy (UTTS) offers the potential to reliably estimate bone mineral density and hence the established T-score parameter for clinical osteoporosis assessment. Copyright © 2015 Elsevier B.V. All rights reserved.

High-Dietary Alpha-Tocopherol or Mixed Tocotrienols Have No Effect on Bone Mass, Density, or Turnover in Male Rats During Skeletal Maturation.

PubMed

Tennant, Katherine G; Leonard, Scott W; Wong, Carmen P; Iwaniec, Urszula T; Turner, Russell T; Traber, Maret G

2017-07-01

High levels of alpha-tocopherol, the usual vitamin E supplement, are reported to decrease bone mass in rodents; however, the effects of other vitamin E forms on the skeleton are unknown. To test the hypothesis that high intakes of various vitamin E forms or the vitamin E metabolite, carboxyethyl hydroxy chromanol, were detrimental to bone status, Sprague-Dawley rats (n = 6 per group, 11-week males) for 18 weeks consumed semipurified diets that contained adequate alpha-tocopherol, high alpha-tocopherol (500 mg/kg diet), or 50% Tocomin (250 mg mixed tocopherols and tocotrienols/kg diet). Vitamin E status was evaluated by measuring plasma, liver, and bone marrow vitamin E concentrations. Bone density, microarchitecture (cross-sectional volume, cortical volume, marrow volume, cortical thickness, and cancellous bone volume fraction, trabecular number, thickness, and spacing), and cancellous bone formation were assessed in the tibia using dual-energy X-ray absorptiometry, microcomputed tomography, and histomorphometry, respectively. In addition, serum osteocalcin was assessed as a global marker of bone turnover; gene expression in response to treatment was evaluated in the femur using targeted (osteogenesis related) gene profiling. No significant differences were detected between treatment groups for any of the bone endpoints measured. Vitamin E supplementation, either as alpha-tocopherol or mixed tocotrienols, while increasing vitamin E concentrations both in plasma and tissues, had no effect on the skeleton in rats.

Biaxial Normal Strength Behavior in the Axial-Transverse Plane for Human Trabecular Bone—Effects of Bone Volume Fraction, Microarchitecture, and Anisotropy

PubMed Central

Sanyal, Arnav; Keaveny, Tony M.

2013-01-01

The biaxial failure behavior of the human trabecular bone, which has potential relevance both for fall and gait loading conditions, is not well understood, particularly for low-density bone, which can display considerable mechanical anisotropy. Addressing this issue, we investigated the biaxial normal strength behavior and the underlying failure mechanisms for human trabecular bone displaying a wide range of bone volume fraction (0.06–0.34) and elastic anisotropy. Micro-computer tomography (CT)-based nonlinear finite element analysis was used to simulate biaxial failure in 15 specimens (5 mm cubes), spanning the complete biaxial normal stress failure space in the axial-transverse plane. The specimens, treated as approximately transversely isotropic, were loaded in the principal material orientation. We found that the biaxial stress yield surface was well characterized by the superposition of two ellipses—one each for yield failure in the longitudinal and transverse loading directions—and the size, shape, and orientation of which depended on bone volume fraction and elastic anisotropy. However, when normalized by the uniaxial tensile and compressive strengths in the longitudinal and transverse directions, all of which depended on bone volume fraction, microarchitecture, and mechanical anisotropy, the resulting normalized biaxial strength behavior was well described by a single pair of (longitudinal and transverse) ellipses, with little interspecimen variation. Taken together, these results indicate that the role of bone volume fraction, microarchitecture, and mechanical anisotropy is mostly accounted for in determining the uniaxial strength behavior and the effect of these parameters on the axial-transverse biaxial normal strength behavior per se is minor. PMID:24121715

Estimation of Local Bone Loads for the Volume of Interest.

PubMed

Kim, Jung Jin; Kim, Youkyung; Jang, In Gwun

2016-07-01

Computational bone remodeling simulations have recently received significant attention with the aid of state-of-the-art high-resolution imaging modalities. They have been performed using localized finite element (FE) models rather than full FE models due to the excessive computational costs of full FE models. However, these localized bone remodeling simulations remain to be investigated in more depth. In particular, applying simplified loading conditions (e.g., uniform and unidirectional loads) to localized FE models have a severe limitation in a reliable subject-specific assessment. In order to effectively determine the physiological local bone loads for the volume of interest (VOI), this paper proposes a novel method of estimating the local loads when the global musculoskeletal loads are given. The proposed method is verified for the three VOI in a proximal femur in terms of force equilibrium, displacement field, and strain energy density (SED) distribution. The effect of the global load deviation on the local load estimation is also investigated by perturbing a hip joint contact force (HCF) in the femoral head. Deviation in force magnitude exhibits the greatest absolute changes in a SED distribution due to its own greatest deviation, whereas angular deviation perpendicular to a HCF provides the greatest relative change. With further in vivo force measurements and high-resolution clinical imaging modalities, the proposed method will contribute to the development of reliable patient-specific localized FE models, which can provide enhanced computational efficiency for iterative computing processes such as bone remodeling simulations.

Tibial bone fractures occurring after medioproximal tibial bone grafts for oral and maxillofacial reconstruction.

PubMed

Kim, Il-Kyu; Cho, Hyun-Young; Pae, Sang-Pill; Jung, Bum-Sang; Cho, Hyun-Woo; Seo, Ji-Hoon

2013-12-01

Oral and maxillofacial defects often require bone grafts to restore missing tissues. Well-recognized donor sites include the anterior and posterior iliac crest, rib, and intercalvarial diploic bone. The proximal tibia has also been explored as an alternative donor site. The use of the tibia for bone graft has many benefits, such as procedural ease, adequate volume of cancellous and cortical bone, and minimal complications. Although patients rarely complain of pain, swelling, discomfort, or dysfunction, such as gait disturbance, both patients and surgeons should pay close attention to such after effects due to the possibility of tibial fracture. The purpose of this study is to analyze tibial fractures that occurring after osteotomy for a medioproximal tibial graft. An analysis was intended for patients who underwent medioproximal tibial graft between March 2004 and December 2011 in Inha University Hospital. A total of 105 subjects, 30 females and 75 males, ranged in age from 17 to 78 years. We investigated the age, weight, circumstance, and graft timing in relation to tibial fracture. Tibial fractures occurred in four of 105 patients. There were no significant differences in graft region, shape, or scale between the fractured and non-fractured patients. Patients who undergo tibial grafts must be careful of excessive external force after the operation.

Bone fractures following external beam radiotherapy and limb-preservation surgery for lower extremity soft tissue sarcoma: relationship to irradiated bone length, volume, tumor location and dose.

PubMed

Dickie, Colleen I; Parent, Amy L; Griffin, Anthony M; Fung, Sharon; Chung, Peter W M; Catton, Charles N; Ferguson, Peter C; Wunder, Jay S; Bell, Robert S; Sharpe, Michael B; O'Sullivan, Brian

2009-11-15

To examine the relationship between tumor location, bone dose, and irradiated bone length on the development of radiation-induced fractures for lower extremity soft tissue sarcoma (LE-STS) patients treated with limb-sparing surgery and radiotherapy (RT). Of 691 LE-STS patients treated from 1989 to 2005, 31 patients developed radiation-induced fractures. Analysis was limited to 21 fracture patients (24 fractures) who were matched based on tumor size and location, age, beam arrangement, and mean total cumulative RT dose to a random sample of 53 nonfracture patients and compared for fracture risk factors. Mean dose to bone, RT field size (FS), maximum dose to a 2-cc volume of bone, and volume of bone irradiated to >or=40 Gy (V40) were compared. Fracture site dose was determined by comparing radiographic images and surgical reports to fracture location on the dose distribution. For fracture patients, mean dose to bone was 45 +/- 8 Gy (mean dose at fracture site 59 +/- 7 Gy), mean FS was 37 +/- 8 cm, maximum dose was 64 +/- 7 Gy, and V40 was 76 +/- 17%, compared with 37 +/- 11 Gy, 32 +/- 9 cm, 59 +/- 8 Gy, and 64 +/- 22% for nonfracture patients. Differences in mean, maximum dose, and V40 were statistically significant (p = 0.01, p = 0.02, p = 0.01). Leg fractures were more common above the knee joint. The risk of radiation-induced fracture appears to be reduced if V40 <64%. Fracture incidence was lower when the mean dose to bone was <37 Gy or maximum dose anywhere along the length of bone was <59 Gy. There was a trend toward lower mean FS for nonfracture patients.

Bone remodelling: its local regulation and the emergence of bone fragility.

PubMed

Martin, T John; Seeman, Ego

2008-10-01

Bone modelling prevents the occurrence of damage by adapting bone structure - and hence bone strength - to its loading circumstances. Bone remodelling removes damage, when it inevitably occurs, in order to maintain bone strength. This cellular machinery is successful during growth, but fails during advancing age because of the development of a negative balance between the volumes of bone resorbed and formed during remodelling by the basic multicellular unit (BMU), high rates of remodelling during midlife in women and late in life in both sexes, and a decline in periosteal bone formation. together resulting in bone loss and structural decay each time a remodelling event occurs. The two steps in remodelling - resorption of a volume of bone by osteoclasts and formation of a comparable volume by osteoblasts - are sequential, but the regulatory events leading to these two fully differentiated functions are not. Reparative remodelling is initiated by damage producing osteocyte apoptosis, which signals the location of damage via the osteocyte canalicular system to endosteal lining cells which forms the canopy of a bone-remodelling compartment (BRC). Within the BRC, local recruitment of osteoblast precursors from the lining cells, the marrow and circulation, direct contact with osteoclast precursors, osteoclastogenesis and molecular cross-talk between precursors, mature cells, cells of the immune system, and products of the resorbed matrix, titrate the birth, work and lifespan of the cells of this multicellular remodelling machinery to either remove or form a net volume of bone appropriate to the mechanical requirements.

Hyoid bone development: An assessment of optimal CT scanner parameters and 3D volume rendering techniques

PubMed Central

Cotter, Meghan M.; Whyms, Brian J.; Kelly, Michael P.; Doherty, Benjamin M.; Gentry, Lindell R.; Bersu, Edward T.; Vorperian, Houri K.

2015-01-01

The hyoid bone anchors and supports the vocal tract. Its complex shape is best studied in three dimensions, but it is difficult to capture on computed tomography (CT) images and three-dimensional volume renderings. The goal of this study was to determine the optimal CT scanning and rendering parameters to accurately measure the growth and developmental anatomy of the hyoid and to determine whether it is feasible and necessary to use these parameters in the measurement of hyoids from in vivo CT scans. Direct linear and volumetric measurements of skeletonized hyoid bone specimens were compared to corresponding CT images to determine the most accurate scanning parameters and three-dimensional rendering techniques. A pilot study was undertaken using in vivo scans from a retrospective CT database to determine feasibility of quantifying hyoid growth. Scanning parameters and rendering technique affected accuracy of measurements. Most linear CT measurements were within 10% of direct measurements; however, volume was overestimated when CT scans were acquired with a slice thickness greater than 1.25 mm. Slice-by-slice thresholding of hyoid images decreased volume overestimation. The pilot study revealed that the linear measurements tested correlate with age. A fine-tuned rendering approach applied to small slice thickness CT scans produces the most accurate measurements of hyoid bones. However, linear measurements can be accurately assessed from in vivo CT scans at a larger slice thickness. Such findings imply that investigation into the growth and development of the hyoid bone, and the vocal tract as a whole, can now be performed using these techniques. PMID:25810349

Hyoid Bone Development: An Assessment Of Optimal CT Scanner Parameters and Three-Dimensional Volume Rendering Techniques.

PubMed

Cotter, Meghan M; Whyms, Brian J; Kelly, Michael P; Doherty, Benjamin M; Gentry, Lindell R; Bersu, Edward T; Vorperian, Houri K

2015-08-01

The hyoid bone anchors and supports the vocal tract. Its complex shape is best studied in three dimensions, but it is difficult to capture on computed tomography (CT) images and three-dimensional volume renderings. The goal of this study was to determine the optimal CT scanning and rendering parameters to accurately measure the growth and developmental anatomy of the hyoid and to determine whether it is feasible and necessary to use these parameters in the measurement of hyoids from in vivo CT scans. Direct linear and volumetric measurements of skeletonized hyoid bone specimens were compared with corresponding CT images to determine the most accurate scanning parameters and three-dimensional rendering techniques. A pilot study was undertaken using in vivo scans from a retrospective CT database to determine feasibility of quantifying hyoid growth. Scanning parameters and rendering technique affected accuracy of measurements. Most linear CT measurements were within 10% of direct measurements; however, volume was overestimated when CT scans were acquired with a slice thickness greater than 1.25 mm. Slice-by-slice thresholding of hyoid images decreased volume overestimation. The pilot study revealed that the linear measurements tested correlate with age. A fine-tuned rendering approach applied to small slice thickness CT scans produces the most accurate measurements of hyoid bones. However, linear measurements can be accurately assessed from in vivo CT scans at a larger slice thickness. Such findings imply that investigation into the growth and development of the hyoid bone, and the vocal tract as a whole, can now be performed using these techniques. © 2015 Wiley Periodicals, Inc.

Relationship between sample volumes and modulus of human vertebral trabecular bone in micro-finite element analysis.

PubMed

Wen, Xin-Xin; Xu, Chao; Zong, Chun-Lin; Feng, Ya-Fei; Ma, Xiang-Yu; Wang, Fa-Qi; Yan, Ya-Bo; Lei, Wei

2016-07-01

Micro-finite element (μFE) models have been widely used to assess the biomechanical properties of trabecular bone. How to choose a proper sample volume of trabecular bone, which could predict the real bone biomechanical properties and reduce the calculation time, was an interesting problem. Therefore, the purpose of this study was to investigate the relationship between different sample volumes and apparent elastic modulus (E) calculated from μFE model. 5 Human lumbar vertebral bodies (L1-L5) were scanned by micro-CT. Cubic concentric samples of different lengths were constructed as the experimental groups and the largest possible volumes of interest (VOI) were constructed as the control group. A direct voxel-to-element approach was used to generate μFE models and steel layers were added to the superior and inferior surface to mimic axial compression tests. A 1% axial strain was prescribed to the top surface of the model to obtain the E values. ANOVA tests were performed to compare the E values from the different VOIs against that of the control group. Nonlinear function curve fitting was performed to study the relationship between volumes and E values. The larger cubic VOI included more nodes and elements, and more CPU times were needed for calculations. E values showed a descending tendency as the length of cubic VOI decreased. When the volume of VOI was smaller than (7.34mm(3)), E values were significantly different from the control group. The fit function showed that E values approached an asymptotic values with increasing length of VOI. Our study demonstrated that apparent elastic modulus calculated from μFE models were affected by the sample volumes. There was a descending tendency of E values as the length of cubic VOI decreased. Sample volume which was not smaller than (7.34mm(3)) was efficient enough and timesaving for the calculation of E. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

PubMed

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 < 0.001). The inclusion of cortical measures, along with the trabecular measures extracted after isotropic volume construction and trabecular enrichment approach procedures, resulted in better estimation of bone strength. The findings suggest that the proposed system using the clinical computed tomography images scanned with low dose could eventually be helpful in osteoporosis diagnosis and its treatment planning. © IMechE 2016.

Accuracy of cancellous bone volume fraction measured by micro-CT scanning.

PubMed

Ding, M; Odgaard, A; Hvid, I

1999-03-01

Volume fraction, the single most important parameter in describing trabecular microstructure, can easily be calculated from three-dimensional reconstructions of micro-CT images. This study sought to quantify the accuracy of this measurement. One hundred and sixty human cancellous bone specimens which covered a large range of volume fraction (9.8-39.8%) were produced. The specimens were micro-CT scanned, and the volume fraction based on Archimedes' principle was determined as a reference. After scanning, all micro-CT data were segmented using individual thresholds determined by the scanner supplied algorithm (method I). A significant deviation of volume fraction from method I was found: both the y-intercept and the slope of the regression line were significantly different from those of the Archimedes-based volume fraction (p < 0.001). New individual thresholds were determined based on a calibration of volume fraction to the Archimedes-based volume fractions (method II). The mean thresholds of the two methods were applied to segment 20 randomly selected specimens. The results showed that volume fraction using the mean threshold of method I was underestimated by 4% (p = 0.001), whereas the mean threshold of method II yielded accurate values. The precision of the measurement was excellent. Our data show that care must be taken when applying thresholds in generating 3-D data, and that a fixed threshold may be used to obtain reliable volume fraction data. This fixed threshold may be determined from the Archimedes-based volume fraction of a subgroup of specimens. The threshold may vary between different materials, and so it should be determined whenever a study series is performed.

Relationship between trabecular texture features of CT images and an amount of bone cement volume injection in percutaneous vertebroplasty

NASA Astrophysics Data System (ADS)

Tack, Gye Rae; Choi, Hyung Guen; Shin, Kyu-Chul; Lee, Sung J.

2001-06-01

Percutaneous vertebroplasty is a surgical procedure that was introduced for the treatment of compression fracture of the vertebrae. This procedure includes puncturing vertebrae and filling with polymethylmethacrylate (PMMA). Recent studies have shown that the procedure could provide structural reinforcement for the osteoporotic vertebrae while being minimally invasive and safe with immediate pain relief. However, treatment failures due to disproportionate PMMA volume injection have been reported as one of complications in vertebroplasty. It is believed that control of PMMA volume is one of the most critical factors that can reduce the incidence of complications. In this study, appropriate amount of PMMA volume was assessed based on the imaging data of a given patient under the following hypotheses: (1) a relationship can be drawn between the volume of PMMA injection and textural features of the trabecular bone in preoperative CT images and (2) the volume of PMMA injection can be estimated based on 3D reconstruction of postoperative CT images. Gray-level run length analysis was used to determine the textural features of the trabecular bone. The width of trabecular (T-texture) and the width of intertrabecular spaces (I-texture) were calculated. The correlation between PMMA volume and textural features of patient's CT images was also examined to evaluate the appropriate PMMA amount. Results indicated that there was a strong correlation between the actual PMMA injection volume and the area of the intertrabecular space and that of trabecular bone calculated from the CT image (correlation coefficient, requals0.96 and requals-0.95, respectively). T- texture (requals-0.93) did correlate better with the actual PMMA volume more than the I-texture (requals0.57). Therefore, it was demonstrated that appropriate PMMA injection volume could be predicted based on the textural analysis for better clinical management of the osteoporotic spine.

Finite Element-Based Mechanical Assessment of Bone Quality on the Basis of In Vivo Images.

PubMed

Pahr, Dieter H; Zysset, Philippe K

2016-12-01

Beyond bone mineral density (BMD), bone quality designates the mechanical integrity of bone tissue. In vivo images based on X-ray attenuation, such as CT reconstructions, provide size, shape, and local BMD distribution and may be exploited as input for finite element analysis (FEA) to assess bone fragility. Further key input parameters of FEA are the material properties of bone tissue. This review discusses the main determinants of bone mechanical properties and emphasizes the added value, as well as the important assumptions underlying finite element analysis. Bone tissue is a sophisticated, multiscale composite material that undergoes remodeling but exhibits a rather narrow band of tissue mineralization. Mechanically, bone tissue behaves elastically under physiologic loads and yields by cracking beyond critical strain levels. Through adequate cell-orchestrated modeling, trabecular bone tunes its mechanical properties by volume fraction and fabric. With proper calibration, these mechanical properties may be incorporated in quantitative CT-based finite element analysis that has been validated extensively with ex vivo experiments and has been applied increasingly in clinical trials to assess treatment efficacy against osteoporosis.

3D SPECT/CT fusion using image data projection of bone SPECT onto 3D volume-rendered CT images: feasibility and clinical impact in the diagnosis of bone metastasis.

PubMed

Ogata, Yuji; Nakahara, Tadaki; Ode, Kenichi; Matsusaka, Yohji; Katagiri, Mari; Iwabuchi, Yu; Itoh, Kazunari; Ichimura, Akira; Jinzaki, Masahiro

2017-05-01

We developed a method of image data projection of bone SPECT into 3D volume-rendered CT images for 3D SPECT/CT fusion. The aims of our study were to evaluate its feasibility and clinical usefulness. Whole-body bone scintigraphy (WB) and SPECT/CT scans were performed in 318 cancer patients using a dedicated SPECT/CT systems. Volume data of bone SPECT and CT were fused to obtain 2D SPECT/CT images. To generate our 3D SPECT/CT images, colored voxel data of bone SPECT were projected onto the corresponding location of the volume-rendered CT data after a semi-automatic bone extraction. Then, the resultant 3D images were blended with conventional volume-rendered CT images, allowing to grasp the three-dimensional relationship between bone metabolism and anatomy. WB and SPECT (WB + SPECT), 2D SPECT/CT fusion, and 3D SPECT/CT fusion were evaluated by two independent reviewers in the diagnosis of bone metastasis. The inter-observer variability and diagnostic accuracy in these three image sets were investigated using a four-point diagnostic scale. Increased bone metabolism was found in 744 metastatic sites and 1002 benign changes. On a per-lesion basis, inter-observer agreements in the diagnosis of bone metastasis were 0.72 for WB + SPECT, 0.90 for 2D SPECT/CT, and 0.89 for 3D SPECT/CT. Receiver operating characteristic analyses for the diagnostic accuracy of bone metastasis showed that WB + SPECT, 2D SPECT/CT, and 3D SPECT/CT had an area under the curve of 0.800, 0.983, and 0.983 for reader 1, 0.865, 0.992, and 0.993 for reader 2, respectively (WB + SPECT vs. 2D or 3D SPECT/CT, p < 0.001; 2D vs. 3D SPECT/CT, n.s.). The durations of interpretation of WB + SPECT, 2D SPECT/CT, and 3D SPECT/CT images were 241 ± 75, 225 ± 73, and 182 ± 71 s for reader 1 and 207 ± 72, 190 ± 73, and 179 ± 73 s for reader 2, respectively. As a result, it took shorter time to read 3D SPECT/CT images than 2D SPECT/CT (p < 0.0001) or WB�

Scaling relations between bone volume and bone structure as found using 3D µCT images of the trabecular bone taken from different skeletal sites

NASA Astrophysics Data System (ADS)

Raeth, Christoph; Müller, Dirk; Sidorenko, Irina; Monetti, Roberto; Eckstein, Felix; Matsuura, Maiko; Lochmüller, Eva-Maria; Zysset, Philippe K.; Bauer, Jan

2010-03-01

According to Wolff's law bone remodels in response to the mechanical stresses it experiences so as to produce a minimal-weight structure that is adapted to its applied stresses. Here, we investigate the relations between bone volume and structure for the trabecular bone using 3D μCT images taken from different skeletal sites in vitro, namely from the distal radii (96 specimens), thoracic (73 specimens) and lumbar vertebrae (78 specimens). We determine the local structure of the trabecular network by calculating isotropic and anisotropic scaling indices (α, αz). These measures have been proven to be able to discriminate rod- from sheet-like structures and to quantify the alignment of structures with respect to a preferential direction as given by the direction of the external force. Comparing global structure measures derived from the scaling indices (mean, standard deviation) with the bone mass (BV/TV) we find that all correlations obey very accurately power laws with scaling exponents of 0.14, 0.12, 0.15 (<α>~), -0.2, -017, -0.17 (σ(αz)), 0.09, 0.05, 0.07 (<~αz>~) and -0.20, -0.11 ,-0.13 (σ(αz)) distal radius, thoracic vertebra and lumbar vertebra respectively. Thus, these relations turn out to be site-independent, albeit the mechanical stresses to which the bones of the forearm and the spine are exposed, are quite different. The similar alignment might not be in agreement with a universal validity of Wolff's law. On the other hand, such universal power law relations may allow to develop additional diagnostic means to better assess healthy and osteoporotic bone.

Histomorphometric study of alveolar bone healing in rats fed a boron-deficient diet.

PubMed

Gorustovich, Alejandro A; Steimetz, Tammy; Nielsen, Forrest H; Guglielmotti, María B

2008-04-01

Bone healing after tooth extraction in rats is a suitable experimental model to study bone formation. Thus, we performed a study to determine the effects of boron (B) deficiency on bone healing by using this model. The first lower right molar of weanling Wistar rats was extracted under anesthesia. The animals were divided into two groups: +B (adequate; 3 mg B/kg diet), and -B (boron-deficient; 0.07 mg/kg diet). The animals in both groups were killed in groups of 10 at 7 and 14 days after surgery. The guidelines of the NIH for the care and use of laboratory animals were observed. The mandibles were resected, fixed, decalcified, and embedded in paraffin. Buccolingually oriented sections were obtained at the level of the mesial alveolus and used for histometric evaluations. Total alveolar volume (TAV) and trabecular bone volume per total volume (BV/TV) in the apical third of the alveolus were determined. Percentages of osteoblast surface (ObS), eroded surface (ES), and quiescent surface (QS) were determined. No statistical significant differences in food intake and body weight were observed. Histomorphometric evaluation found -B rats had 36% and 63% reductions in BV/TV at 7 and 14 days, respectively. When compared with +B rats, -B rats had significant reductions (57% and 87%) in ObS concomitantly with increases (120% and 126%) in QS at 7 and 14 days, respectively. The findings show that boron deficiency results in altered bone healing because of a marked reduction in osteogenesis. 2008 Wiley-Liss, Inc

Space flight and bone formation.

PubMed

Doty, St B

2004-12-01

Major physiological changes which occur during spaceflight include bone loss, muscle atrophy, cardiovascular and immune response alterations. When trying to determine the reason why bone loss occurs during spaceflight, one must remember that all these other changes in physiology and metabolism may also have impact on the skeletal system. For bone, however, the role of normal weight bearing is a major concern and we have found no adequate substitute for weight bearing which can prevent bone loss. During the study of this problem, we have learned a great deal about bone physiology and increased our knowledge about how normal bone is formed and maintained. Presently, we do not have adequate ground based models which can mimic the tissue loss that occurs in spaceflight but this condition closely resembles the bone loss seen with osteoporosis. Although a normal bone structure will respond to application of mechanical force and weight bearing by forming new bone, a weakened osteoporotic bone may have a tendency to fracture. The study of the skeletal system during weightless conditions will eventually produce preventative measures and form a basis for protecting the crew during long term space flight. The added benefit from these studies will be methods to treat bone loss conditions which occur here on earth.

Space flight and bone formation

NASA Technical Reports Server (NTRS)

Doty, St B.

2004-01-01

Major physiological changes which occur during spaceflight include bone loss, muscle atrophy, cardiovascular and immune response alterations. When trying to determine the reason why bone loss occurs during spaceflight, one must remember that all these other changes in physiology and metabolism may also have impact on the skeletal system. For bone, however, the role of normal weight bearing is a major concern and we have found no adequate substitute for weight bearing which can prevent bone loss. During the study of this problem, we have learned a great deal about bone physiology and increased our knowledge about how normal bone is formed and maintained. Presently, we do not have adequate ground based models which can mimic the tissue loss that occurs in spaceflight but this condition closely resembles the bone loss seen with osteoporosis. Although a normal bone structure will respond to application of mechanical force and weight bearing by forming new bone, a weakened osteoporotic bone may have a tendency to fracture. The study of the skeletal system during weightless conditions will eventually produce preventative measures and form a basis for protecting the crew during long term space flight. The added benefit from these studies will be methods to treat bone loss conditions which occur here on earth.

Associated among endocrine, inflammatory, and bone markers, body composition and weight loss induced bone loss

USDA-ARS?s Scientific Manuscript database

Weight loss reduces co-¬morbidities of obesity but decreases bone mass. Our aims were to determine whether adequate dairy intake could prevent weight loss related bone loss and to evaluate the contribution of energy-related hormones and inflammatory markers to bone metabolism. Overweight and obese w...

Bone marrow blood vessel ossification and "microvascular dead space" in rat and human long bone.

PubMed

Prisby, Rhonda D

2014-07-01

Severe calcification of the bone microvascular network was observed in rats, whereby the bone marrow blood vessels appeared ossified. This study sought to characterize the magnitude of ossification in relation to patent blood vessels and adipocyte content in femoral diaphyses. Additionally, this study confirmed the presence of ossified vessels in patients with arteriosclerotic vascular disease and peripheral vascular disease and cellulitis. Young (4-6 month; n=8) and old (22-24 month; n=8) male Fischer-344 rats were perfused with barium sulfate to visualize patent bone marrow blood vessels. Femoral shafts were processed for bone histomorphometry to quantify ossified (Goldner's Trichrome) and calcified (Alizarin Red) vessels. Adipocyte content was also determined. Additional femora (n=5/age group) were scanned via μCT to quantify microvascular ossification. Bone marrow blood vessels from the rats and the human patients were also isolated and examined via microscopy. Ossified vessels (rats and humans) had osteocyte lacunae on the vessel surfaces and "normal" vessels were transitioning into bone. The volume of ossified vessels was 4800% higher (p<0.05) in the old vs. young rats. Calcified and ossified vessel volumes per tissue volume and calcified vessel volume per patent vessel volume were augmented (p<0.05) 262%, 375% and 263%, respectively, in the old vs. young rats. Ossified and patent vessel number was higher (171%) and lower (40%), respectively, in the old vs. young rats. Finally, adipocyte volume per patent vessel volume was higher (86%) with age. This study is the first to report ossification of bone marrow blood vessels in rats and humans. Ossification presumably results in "microvascular dead space" in regard to loss of patency and vasomotor function as opposed to necrosis. Progression of bone microvascular ossification may provide the common link associated with age-related changes in bone and bone marrow. The clinical implications may be evident in the

Hypergravity suppresses bone resorption in ovariectomized rats

NASA Astrophysics Data System (ADS)

Ikawa, Tesshu; Kawaguchi, Amu; Okabe, Takahiro; Ninomiya, Tadashi; Nakamichi, Yuko; Nakamura, Midori; Uehara, Shunsuke; Nakamura, Hiroaki; Udagawa, Nobuyuki; Takahashi, Naoyuki; Nakamura, Hiroaki; Wakitani, Shigeyuki

2011-04-01

The effects of gravity on bone metabolism are unclear, and little has been reported about the effects of hypergravity on the mature skeleton. Since low gravity has been shown to decrease bone volume, we hypothesized that hypergravity increases bone volume. To clarify this hypothesis, adult female rats were ovariectomized and exposed to hypergravity (2.9G) using a centrifugation system. The rats were killed 28 days after the start of loading, and the distal femoral metaphysis of the rats was studied. Bone architecture was assessed by micro-computed tomography (micro-CT) and bone mineral density was measured using peripheral quantitative CT (pQCT). Hypergravity increased the trabecular bone volume of ovariectomized rats. Histomorphometric analyses revealed that hypergravity suppressed both bone formation and resorption and increased bone volume in ovariectomized rats. Further, the cell morphology, activity, proliferation, and differentiation of osteoclasts and osteoblasts exposed to hypergravity were evaluated in vitro. Hypergravity inhibited actin ring formation in mature osteoclasts, which suggested that the osteoclast activity was suppressed. However, hypergravity had no effect on osteoblasts. These results suggest that hypergravity can stimulate an increase in bone volume by suppressing bone resorption in ovariectomized rats.

Experiment K305: Quantitative analysis of selected bone parameters. Supplement 2: Bone elongation rate and bone mass in metaphysis of long bones

NASA Technical Reports Server (NTRS)

Jee, W. S. S.; Kimmel, D. B.; Smith, C.; Dell, R. B.

1981-01-01

The proximal humeral metaphysis of rats from time periods recovery plus zero days (R+0), recovery plus six days (R+6), and recovery plus twenty nine days (R+29) was analyzed. The volume of calcified cartilage and bone in flight and synchronous controls was reduced in groups R+0 and R+6, but was normal in group R+29. The number of functional bone cells (osteoblasts and osteoclasts) was decreased in proportion to the amount of bone in the early groups, and was normal in the last group. The fatty marrow volume was increased only in flight animals of groups R+0 and R+6, but was normal in the R+29 group. Accumulation of excess fatty marrow was seen only in flight animals. The decreased amount of bone and calcified cartilage is believed to be the result of a temporarily slowed or arrested production of calcified cartilage as a substrate for bone formation. This would have resulted from slowed bone elongation during flight and synchronous control conditions. Bone elongation returned to normal by twenty nine days after return.

Bone Marrow Blood Vessel Ossification and “Microvascular Dead Space” in Rat and Human Long Bone

PubMed Central

Prisby, Rhonda D.

2014-01-01

Severe calcification of the bone microvascular network was observed in rats, whereby the bone marrow blood vessels appeared ossified. This study sought to characterize the magnitude of ossification in relation to patent blood vessels and adipocyte content in femoral diaphyses. Additionally, this study confirmed the presence of ossified vessels in patients with arteriosclerotic vascular disease and peripheral vascular disease and cellulitis. Young (4–6 mon; n=8) and old (22–24 mon; n=8) male Fischer-344 rats were perfused with barium sulfate to visualize patent bone marrow blood vessels. Femoral shafts were processed for bone histomorphometry to quantify ossified (Goldner’s Trichrome) and calcified (Alizarin Red) vessels. Adipocyte content was also determined. Additional femora (n=5/age group) were scanned via µCT to quantify microvascular ossification. Bone marrow blood vessels from rats and the human patients were also isolated and examined via microscopy. Ossified vessels (rats and humans) had osteocyte lacunae on the vessel surfaces and “normal” vessels were transitioning into bone. The volume of ossified vessels was 4800% higher (p <0.05) in old vs. young rats. Calcified and ossified vessel volumes per tissue volume and calcified vessel volume per patent vessel volume were augmented (p <0.05) 262%, 375% and 263%, respectively, in old vs. young rats. Ossified and patent vessel number was higher (171%) and lower (40%), respectively, in old vs. young rats. Finally, adipocyte volume per patent vessel volume was higher (86%) with age. This study is the first to report ossification of bone marrow blood vessels in rats and humans. Ossification presumably results in “microvascular dead space” in regards to loss of patency and vasomotor function as opposed to necrosis. The progression of bone microvascular ossification may provide the common link associated with age-related changes in bone and bone marrow. The clinical implications may be evident in the

Multi-atlas segmentation of the cartilage in knee MR images with sequential volume- and bone-mask-based registrations

NASA Astrophysics Data System (ADS)

Lee, Han Sang; Kim, Hyeun A.; Kim, Hyeonjin; Hong, Helen; Yoon, Young Cheol; Kim, Junmo

2016-03-01

In spite of its clinical importance in diagnosis of osteoarthritis, segmentation of cartilage in knee MRI remains a challenging task due to its shape variability and low contrast with surrounding soft tissues and synovial fluid. In this paper, we propose a multi-atlas segmentation of cartilage in knee MRI with sequential atlas registrations and locallyweighted voting (LWV). First, bone is segmented by sequential volume- and object-based registrations and LWV. Second, to overcome the shape variability of cartilage, cartilage is segmented by bone-mask-based registration and LWV. In experiments, the proposed method improved the bone segmentation by reducing misclassified bone region, and enhanced the cartilage segmentation by preventing cartilage leakage into surrounding similar intensity region, with the help of sequential registrations and LWV.

Vitamin E provides protection for bone in mature hindlimb unloaded male rats

NASA Technical Reports Server (NTRS)

Smith, B. J.; Lucas, E. A.; Turner, R. T.; Evans, G. L.; Lerner, M. R.; Brackett, D. J.; Stoecker, B. J.; Arjmandi, B. H.

2005-01-01

The deleterious effects of skeletal unloading on bone mass and strength may, in part, result from increased production of oxygen-derived free radicals and proinflammatory cytokines. This study was designed to evaluate the ability of vitamin E (alpha-tocopherol), a free-radical scavenger with antiinflammatory properties, to protect against bone loss caused by skeletal unloading in mature male Sprague-Dawley rats. A 2 x 3 factorial design was used with either hindlimb unloading (HU) or normal loading (ambulatory; AMB), and low-dose (LD; 15 IU/kg diet), adequate-dose (AD; 75 IU/kg diet), or high-dose (HD; 500 IU/kg diet) vitamin E (DL-alpha-tocopherol acetate). To optimize the effects of vitamin E on bone, dietary treatments were initiated 9 weeks prior to unloading and continued during the 4-week unloading period, at which time animals were euthanized and blood and tissue samples were collected. Serum vitamin E was dose-dependently increased, confirming the vitamin E status of animals. The HD treatment improved oxidation parameters, as indicated by elevated serum ferric-reducing ability and a trend toward reducing tissue lipid peroxidation. Histomorphometric analysis of the distal femur revealed significant reductions in trabecular thickness (TbTh), double-labeled surface (dLS/BS), and rate of bone formation to bone volume (BFR/BV) due by HU. AMB animals on the HD diet and HU animals on the LD diet had reduced bone surface normalized to tissue volume (BS/TV) and trabecular number (TbN); however, the HD vitamin E protected against these changes in the HU animals. Our findings suggest that vitamin E supplementation provides modest bone protective effects during skeletal unloading.

A quantification strategy for missing bone mass in case of osteolytic bone lesions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fränzle, Andrea, E-mail: a.fraenzle@dkfz.de; Giske, Kristina; Bretschi, Maren

Purpose: Most of the patients who died of breast cancer have developed bone metastases. To understand the pathogenesis of bone metastases and to analyze treatment response of different bone remodeling therapies, preclinical animal models are examined. In breast cancer, bone metastases are often bone destructive. To assess treatment response of bone remodeling therapies, the volumes of these lesions have to be determined during the therapy process. The manual delineation of missing structures, especially if large parts are missing, is very time-consuming and not reproducible. Reproducibility is highly important to have comparable results during the therapy process. Therefore, a computerized approachmore » is needed. Also for the preclinical research, a reproducible measurement of the lesions is essential. Here, the authors present an automated segmentation method for the measurement of missing bone mass in a preclinical rat model with bone metastases in the hind leg bones based on 3D CT scans. Methods: The affected bone structure is compared to a healthy model. Since in this preclinical rat trial the metastasis only occurs on the right hind legs, which is assured by using vessel clips, the authors use the left body side as a healthy model. The left femur is segmented with a statistical shape model which is initialised using the automatically segmented medullary cavity. The left tibia and fibula are segmented using volume growing starting at the tibia medullary cavity and stopping at the femur boundary. Masked images of both segmentations are mirrored along the median plane and transferred manually to the position of the affected bone by rigid registration. Affected bone and healthy model are compared based on their gray values. If the gray value of a voxel indicates bone mass in the healthy model and no bone in the affected bone, this voxel is considered to be osteolytic. Results: The lesion segmentations complete the missing bone structures in a reasonable way

Bone-specific gene expression patterns and whole bone tissue of female mice are programmed by early life exposure to soy isoflavones and folic acid.

PubMed

Kaludjerovic, Jovana; Ward, Wendy E

2015-10-01

Female mice exposed to soy isoflavones (ISO) during early postnatal life have improved bone outcomes at adulthood. Since long-lasting effects may be mediated by DNA methylation, we hypothesized that providing supplemental folic acid (FA), a methyl donor, during early life, would enhance the positive effect of ISO to bone health. Bone-specific gene expression patterns were studied to understand potential mechanisms. CD-1 dams (n=36) were randomized to adequate or supplemental levels of FA (2 or 8 mg/kg diet) during pregnancy and lactation, and offspring received corn oil or ISO (7 mg/kg body weight/d) from postnatal day 1 to 10. From weaning, pups were fed an adequate FA diet and were studied to 4 months of age. Female offspring exposed to supplemental FA+ISO had higher bone mineral density (BMD), trabecular connectivity and peak load at the lumbar spine compared to females exposed to adequate FA. Female offspring exposed to adequate FA+ISO or supplemental FA had higher (P<.05) BMD and greater resistance to fracture at the lumbar spine and the femur; higher trabecular connectivity at the lumbar spine; and lower expression of DNA methyltransferase 3a (Dnmt3a) and neuropeptide Y (NPY) in the femur compared to mice exposed to adequate FA. In addition, only mice exposed to adequate FA+ISO had microstructural improvements at the femur neck and higher serum osteoprotegrin (OPG) and insulin growth factor-I (IGF-I). In summary, exposure to supplemental FA did not enhance the positive effect of ISO in bone. However, exposure to adequate FA+ISO or supplemental FA improved bone at least in part by suppressing Dnmt3a and NPY. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Vastus medialis cross-sectional area is positively associated with patella cartilage and bone volumes in a pain-free community-based population

PubMed Central

Berry, Patricia A; Teichtahl, Andrew J; Galevska-Dimitrovska, Ana; Hanna, Fahad S; Wluka, Anita E; Wang, Yuanyuan; Urquhart, Donna M; English, Dallas R; Giles, Graham G; Cicuttini, Flavia M

2008-01-01

Introduction Although vastus medialis and lateralis are important determinants of patellofemoral joint function, their relationship with patellofemoral joint structure is unknown. The aim of this study was to examine potential determinants of vastus medialis and lateralis cross-sectional areas and the relationship between the cross-sectional area and patella cartilage and bone volumes. Methods Two hundred ninety-seven healthy adult subjects had magnetic resonance imaging of their dominant knee. Vastus medialis and lateralis cross-sectional areas were measured 37.5 mm superior to the quadriceps tendon insertion at the proximal pole of the patella. Patella cartilage and bone volumes were measured from these images. Demographic data and participation in vigorous physical activity were assessed by questionnaire. Results The determinants of increased vastus medialis and lateralis cross-sectional areas were older age (P ≤ 0.002), male gender (P < 0.001), and greater body mass index (P ≤ 0.07). Participation in vigorous physical activity was positively associated with vastus medialis cross-sectional area (regression coefficient [beta] 90.0; 95% confidence interval [CI] 38.2, 141.7) (P < 0.001) but not with vastus lateralis cross-sectional area (beta 10.1; 95% CI -18.1, 38.3) (P = 0.48). The cross-sectional area of vastus medialis only was positively associated with patella cartilage volume (beta 0.6; 95% CI 0.23, 0.94) (P = 0.001) and bone volume (beta 3.0; 95% CI 1.40, 4.68) (P < 0.001) after adjustment for potential confounders. Conclusions Our results in a pain-free community-based population suggest that increased cross-sectional area of vastus medialis, which is associated with vigorous physical activity, and increased patella cartilage and bone volumes may benefit patellofemoral joint health and reduce the long-term risk of patellofemoral pathology. PMID:19077298

Cortical bone deficit and fat infiltration of bone marrow and skeletal muscle in ambulatory children with mild spastic cerebral palsy.

PubMed

Whitney, Daniel G; Singh, Harshvardhan; Miller, Freeman; Barbe, Mary F; Slade, Jill M; Pohlig, Ryan T; Modlesky, Christopher M

2017-01-01

Nonambulatory children with severe cerebral palsy (CP) have underdeveloped bone architecture, low bone strength and a high degree of fat infiltration in the lower extremity musculature. The present study aims to determine if such a profile exists in ambulatory children with mild CP and if excess fat infiltration extends into the bone marrow. Ambulatory children with mild spastic CP and typically developing children (4 to 11years; 12/group) were compared. Magnetic resonance imaging was used to estimate cortical bone, bone marrow and total bone volume and width, bone strength [i.e., section modulus (Z) and polar moment of inertia (J)], and bone marrow fat concentration in the midtibia, and muscle volume, intermuscular, subfascial, and subcutaneous adipose tissue (AT) volume and intramuscular fat concentration in the midleg. Accelerometer-based activity monitors worn on the ankle were used to assess physical activity. There were no group differences in age, height, body mass, body mass percentile, BMI, BMI percentile or tibia length, but children with CP had lower height percentile (19th vs. 50th percentile) and total physical activity counts (44%) than controls (both p<0.05). Children with CP also had lower cortical bone volume (30%), cortical bone width in the posterior (16%) and medial (32%) portions of the shaft, total bone width in the medial-lateral direction (15%), Z in the medial-lateral direction (34%), J (39%) and muscle volume (39%), and higher bone marrow fat concentration (82.1±1.8% vs. 80.5±1.9%), subfascial AT volume (3.3 fold) and intramuscular fat concentration (25.0±8.0% vs. 16.1±3.3%) than controls (all p<0.05). When tibia length was statistically controlled, all group differences in bone architecture, bone strength, muscle volume and fat infiltration estimates, except posterior cortical bone width, were still present (all p<0.05). Furthermore, a higher intermuscular AT volume in children with CP compared to controls emerged (p<0.05). Ambulatory

[Diet, nutrition and bone health].

PubMed

Miggiano, G A D; Gagliardi, L

2005-01-01

Nutrition is an important "modifiable" factor in the development and maintenance of bone mass and in the prevention of osteoporosis. The improvement of calcium intake in prepuberal age translates to gain in bone mass and, with genetic factor, to achievement of Peak Bone Mass (PBM), the higher level of bone mass reached at the completion of physiological growth. Individuals with higher PBM achieved in early adulthood will be at lower risk for developing osteoporosis later in life. Achieved the PBM, it is important maintain the bone mass gained and reduce the loss. This is possible adopting a correct behaviour eating associated to regular physical activity and correct life style. The diet is nutritionally balanced with caloric intake adequate to requirement of individual. This is moderate in protein (1 g/kg/die), normal in fat and the carbohydrates provide 55-60% of the caloric intake. A moderate intake of proteins is associated with normal calcium metabolism and presumably does'nt alter bone turnover. An adequate intake of alkali-rich foods may help promote a favorable effect of dietary protein on the skeleton. Lactose intolerance may determinate calcium malabsorption or may decrease calcium intake by elimination of milk and dairy products. Omega3 fatty acids may "down-regulate" pro-inflammatory cytokines and protect against bone loss by decreasing osteoclast activation and bone reabsorption. The diet is characterized by food containing high amount of calcium, potassium, magnesium and low amount of sodium. If it is impossible to reach the requirement with only diet, it is need the supplement of calcium and vitamin D. Other vitamins (Vit. A, C, E, K) and mineral (phosphorus, fluoride, iron, zinc, copper and boron) are required for normal bone metabolism, thus it is need adequate intake of these dietary components. It is advisable reduce ethanol, caffeine, fibers, phytic and ossalic acid intake. The efficacy of phytoestrogens is actually under investigation. Some

Association of baseline knee bone size, cartilage volume, and body mass index with knee cartilage loss over time: a longitudinal study in younger or middle-aged adults.

PubMed

Antony, Benny; Ding, Changhai; Stannus, Oliver; Cicuttini, Flavia; Jones, Graeme

2011-09-01

To determine the association of knee bone size, cartilage volume, and body mass index (BMI) at baseline with knee cartilage loss over 2 years in younger or middle-aged adults. A total of 324 subjects (mean age 45 yrs, range 26-61) were measured at baseline and about 2 years later. Knee cartilage volume and bone size were determined using T1-weighted fat-saturated magnetic resonance imaging. In multivariable analysis, baseline knee bone size was negatively associated with annual change in knee cartilage volume at medial and lateral tibial sites (ß = -0.62% to -0.47%/cm(2), all p < 0.001). The associations disappeared at medial tibial site after adjustment for baseline cartilage volume and became of borderline statistical significance at lateral tibial site after adjustment for both baseline cartilage volume and osteophytes (ß = -0.29, p = 0.059). Baseline knee cartilage volume was consistently and negatively associated with annual change in knee cartilage volume at all 3 medial tibial, lateral tibial, and patellar sites (ß = -4.41% to -1.37%/ml, all p < 0.001). Baseline BMI was negatively associated with an annual change in knee cartilage volume, but only in subjects within the upper tertile of baseline cartilage volume, even after adjusting for cartilage defects (ß = -0.16% to -0.34%/kg/m(2), all p < 0.05). Our study suggests that both higher baseline tibial bone area and knee cartilage volume (most likely due to cartilage swelling) are associated with greater knee cartilage loss over 2 years. A higher BMI was associated with greater knee cartilage loss only in subjects with higher baseline cartilage volume.

Peak bone strength is influenced by calcium intake in growing rats.

PubMed

Viguet-Carrin, S; Hoppler, M; Membrez Scalfo, F; Vuichoud, J; Vigo, M; Offord, E A; Ammann, P

2014-11-01

In this study we investigated the effect of supplementing the diet of the growing male rat with different levels of calcium (from low to higher than recommended intakes at constant Ca/P ratio), on multiple factors (bone mass, strength, size, geometry, material properties, turnover) influencing bone strength during the bone accrual period. Rats, age 28days were supplemented for 4weeks with high Ca (1.2%), adequate Ca (0.5%) or low Ca level (0.2%). Bone metabolism and structural parameters were measured. No changes in body weight or food intake were observed among the groups. As anticipated, compared to the adequate Ca intake, low-Ca intake had a detrimental impact on bone growth (33.63 vs. 33.68mm), bone strength (-19.7% for failure load), bone architecture (-58% for BV/TV) and peak bone mass accrual (-29% for BMD) due to the hormonal disruption implied in Ca metabolism. In contrast, novel, surprising results were observed in that higher than adequate Ca intake resulted in improved peak bone strength (106 vs. 184N/mm for the stiffness and 61 vs. 89N for the failure load) and bone material properties (467 vs. 514mPa for tissue hardness) but these effects were not accompanied by changes in bone mass, size, microarchitecture or bone turnover. Hormonal factors, IGF-I and bone modeling were also evaluated. Compared to the adequate level of Ca, IGF-I level was significantly lower in the low-Ca intake group and significantly higher in the high-Ca intake group. No detrimental effects of high Ca were observed on bone modeling (assessed by histomorphometry and bone markers), at least in this short-term intervention. In conclusion, the decrease in failure load in the low calcium group can be explained by the change in bone geometry and bone mass parameters. Thus, improvements in mechanical properties can be explained by the improved quality of intrinsic bone tissue as shown by nanoindentation. These results suggest that supplemental Ca may be beneficial for the attainment of

Bone Balance within a Cortical BMU: Local Controls of Bone Resorption and Formation

PubMed Central

Smith, David W.; Gardiner, Bruce S.; Dunstan, Colin

2012-01-01

Maintaining bone volume during bone turnover by a BMU is known as bone balance. Balance is required to maintain structural integrity of the bone and is often dysregulated in disease. Consequently, understanding how a BMU controls bone balance is of considerable interest. This paper develops a methodology for identifying potential balance controls within a single cortical BMU. The theoretical framework developed offers the possibility of a directed search for biological processes compatible with the constraints of balance control. We first derive general control constraint equations and then introduce constitutive equations to identify potential control processes that link key variables that describe the state of the BMU. The paper describes specific local bone volume balance controls that may be associated with bone resorption and bone formation. Because bone resorption and formation both involve averaging over time, short-term fluctuations in the environment are removed, leaving the control systems to manage deviations in longer-term trends back towards their desired values. The length of time for averaging is much greater for bone formation than for bone resorption, which enables more filtering of variability in the bone formation environment. Remarkably, the duration for averaging of bone formation may also grow to control deviations in long-term trends of bone formation. Providing there is sufficient bone formation capacity by osteoblasts, this leads to an extraordinarily robust control mechanism that is independent of either osteoblast number or the cellular osteoid formation rate. A complex picture begins to emerge for the control of bone volume. Different control relationships may achieve the same objective, and the ‘integration of information’ occurring within a BMU may be interpreted as different sets of BMU control systems coming to the fore as different information is supplied to the BMU, which in turn leads to different observable BMU behaviors

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

PubMed

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 (<α>), 0.07 to 0.11 (<αz>), -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.

Sodium selenate treatment mitigates reduction of bone volume following traumatic brain injury in rats.

PubMed

Brady, R D; Grills, B L; Romano, T; Wark, J D; O'Brien, T J; Shultz, S R; McDonald, S J

2016-12-14

Administration of sodium selenate to rats given traumatic brain injury (TBI) attenuates brain damage and improves long-term behavioural outcomes. We have previously provided evidence that TBI causes bone loss in rats, however the effect of sodium selenate treatment on bone quantity following TBI is unknown. Rats were randomly assigned into sham injury or fluid percussion injury (FPI) groups and administered saline or sodium selenate for 12 weeks post-injury. Femora were analysed using histomorphometry, peripheral quantitative computed tomography (pQCT) and biomechanical testing. Distal metaphyseal trabecular bone volume fraction of FPI-selenate rats was higher than FPI-vehicle rats (41.8%; p<0.01), however, femora from selenate-treated groups were shorter in length (4.3%; p<0.01) and had increased growth plate width (22.1%; p<0.01), indicating that selenate impaired long bone growth. pQCT analysis demonstrated that distal metaphyseal cortical thickness was decreased in TBI rats compared to shams (11.7%; p<0.05), however selenate treatment to TBI animals offset this reduction (p<0.05). At the midshaft we observed no differences in biomechanical measures. These are the first findings to indicate that mitigating TBI-induced neuropathology may have the added benefit of preventing osteoporosis and associated fracture risk following TBI.

Bone vascularization: a way to study bone microarchitecture?

NASA Astrophysics Data System (ADS)

Blery, P.; Autrusseau, F.; Crauste, E.; Freuchet, Erwan; Weiss, Pierre; Guédon, J.-P.; Amouriq, Y.

2014-03-01

Trabecular bone and its microarchitecture are of prime importance for health. Studying vascularization helps to better know the relationship between bone and vascular microarchitecture. This research is an animal study (nine Lewis rats), based on the perfusion of vascularization by a contrast agent (a mixture of 50% barium sulfate with 1.5% of gelatin) before euthanasia. The samples were studied by micro CT at a resolution of 9μm. Softwares were used to show 3D volumes of bone and vessels, to calculate bone and vessels microarchitecture parameters. This study aims to understand simultaneously the bone microarchitecture and its vascular microarchitecture.

Personalized models of bones based on radiographic photogrammetry.

PubMed

Berthonnaud, E; Hilmi, R; Dimnet, J

2009-07-01

The radiographic photogrammetry is applied, for locating anatomical landmarks in space, from their two projected images. The goal of this paper is to define a personalized geometric model of bones, based uniquely on photogrammetric reconstructions. The personalized models of bones are obtained from two successive steps: their functional frameworks are first determined experimentally, then, the 3D bone representation results from modeling techniques. Each bone functional framework is issued from direct measurements upon two radiographic images. These images may be obtained using either perpendicular (spine and sacrum) or oblique incidences (pelvis and lower limb). Frameworks link together their functional axes and punctual landmarks. Each global bone volume is decomposed in several elementary components. Each volumic component is represented by simple geometric shapes. Volumic shapes are articulated to the patient's bone structure. The volumic personalization is obtained by best fitting the geometric model projections to their real images, using adjustable articulations. Examples are presented to illustrating the technique of personalization of bone volumes, directly issued from the treatment of only two radiographic images. The chosen techniques for treating data are then discussed. The 3D representation of bones completes, for clinical users, the information brought by radiographic images.

Kinetic examination of femoral bone modeling in broilers.

PubMed

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

Endochondral fracture healing with external fixation in the Sost knockout mouse results in earlier fibrocartilage callus removal and increased bone volume fraction and strength.

PubMed

Morse, A; Yu, N Y C; Peacock, L; Mikulec, K; Kramer, I; Kneissel, M; McDonald, M M; Little, D G

2015-02-01

Sclerostin deficiency, via genetic knockout or anti-Sclerostin antibody treatment, has been shown to cause increased bone volume, density and strength of calluses following endochondral bone healing. However, there is limited data on the effect of Sclerostin deficiency on the formative early stage of fibrocartilage (non-bony tissue) formation and removal. In this study we extensively investigate the early fibrocartilage callus. Closed tibial fractures were performed on Sost(-/-) mice and age-matched wild type (C57Bl/6J) controls and assessed at multiple early time points (7, 10 and 14days), as well as at 28days post-fracture after bony union. External fixation was utilized, avoiding internal pinning and minimizing differences in stability stiffness, a variable that has confounded previous research in this area. Normal endochondral ossification progressed in wild type and Sost(-/-) mice with equivalent volumes of fibrocartilage formed at early day 7 and day 10 time points, and bony union in both genotypes by day 28. There were no significant differences in rate of bony union; however there were significant increases in fibrocartilage removal from the Sost(-/-) fracture calluses at day 14 suggesting earlier progression of endochondral healing. Earlier bone formation was seen in Sost(-/-) calluses over wild type with greater bone volume at day 10 (221%, p<0.01). The resultant Sost(-/-) united bony calluses at day 28 had increased bone volume fraction compared to wild type calluses (24%, p<0.05), and the strength of the fractured Sost(-/-) tibiae was greater than that that of wild type fractured tibiae. In summary, bony union was not altered by Sclerostin deficiency in externally-fixed closed tibial fractures, but fibrocartilage removal was enhanced and the resultant united bony calluses had increased bone fraction and increased strength. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

Posttraumatic Bone Marrow Lesion Volume and Knee Pain Within 4 Weeks After Anterior Cruciate Ligament Injury

PubMed Central

Lohmander, Stefan; Frobell, Richard B.

2017-01-01

Context:  After an anterior cruciate ligament (ACL) injury, a majority of patients have a traumatic bone marrow lesion (BML, or bone bruise). The clinical relevance of posttraumatic lesions remains unclear. Objective:  To explore the cross-sectional associations between traumatic BML volume and self-reported knee pain and symptoms among individuals within 4 weeks of ACL injury. Design:  Cross-sectional exploratory analysis of a randomized clinical trial. Setting:  Orthopaedic departments at 2 hospitals in Sweden. Patients or Other Participants:  As part of a randomized trial (knee anterior cruciate ligament nonoperative versus operative treatment [KANON] study), 121 young active adults (74% men, age = 26 ± 5 years, height = 1.8 ± 0.1 m, weight = 76 ± 13 kg) with an ACL tear were studied. Main Outcome Measure(s):  The BML volume in the proximal tibia and distal femur was segmented using magnetic resonance images obtained within 4 weeks of injury. A radiologist evaluated the presence of depression fractures on the images. Pain and symptoms of the injured knee (Knee Injury and Osteoarthritis Outcome Score [KOOS] pain and symptoms subscales) were obtained the same day as imaging. We used linear regression models to assess the associations. Results:  Most knees had at least 1 BML (96%), and the majority (57%) had a depression fracture. Whole-knee BML volume was not related to knee pain for the entire cohort (β = −0.09, P = .25). Among those without a depression fracture, larger whole-knee BML volume was associated with increased knee pain (β = –0.46, P = .02), whereas no association was found for those with a depression fracture (β = 0.0, P = .96). Larger medial (β = –0.48, P = .02) but not lateral (β = –0.03, P = .77) tibiofemoral BML volume was associated with greater pain. We found no association between BML volume and knee symptoms. Conclusions:  We confirmed the absence of relationships between whole-knee BML volume and pain and

Bone nutrients for vegetarians.

PubMed

Mangels, Ann Reed

2014-07-01

The process of bone mineralization and resorption is complex and is affected by numerous factors, including dietary constituents. Although some dietary factors involved in bone health, such as calcium and vitamin D, are typically associated with dairy products, plant-based sources of these nutrients also supply other key nutrients involved in bone maintenance. Some research suggests that vegetarian diets, especially vegan diets, are associated with lower bone mineral density (BMD), but this does not appear to be clinically significant. Vegan diets are not associated with an increased fracture risk if calcium intake is adequate. Dietary factors in plant-based diets that support the development and maintenance of bone mass include calcium, vitamin D, protein, potassium, and soy isoflavones. Other factors present in plant-based diets such as oxalic acid and phytic acid can potentially interfere with absorption and retention of calcium and thereby have a negative effect on BMD. Impaired vitamin B-12 status also negatively affects BMD. The role of protein in calcium balance is multifaceted. Overall, calcium and protein intakes in accord with Dietary Reference Intakes are recommended for vegetarians, including vegans. Fortified foods are often helpful in meeting recommendations for calcium and vitamin D. Plant-based diets can provide adequate amounts of key nutrients for bone health. © 2014 American Society for Nutrition.

Cortical bone deficit and fat infiltration of bone marrow and skeletal muscle in ambulatory children with mild spastic cerebral palsy

PubMed Central

Whitney, Daniel G.; Singh, Harshvardhan; Miller, Freeman; Barbe, Mary F.; Slade, Jill M.; Pohlig, Ryan T.; Modlesky, Christopher M.

2016-01-01

Introduction Nonambulatory children with severe cerebral palsy (CP) have an underdeveloped bone architecture, low bone strength and a high degree of fat infiltration in the lower extremity musculature. The present study aims to determine if such a profile exists in ambulatory children with mild CP and if excess fat infiltration extends into the bone marrow. Materials and methods Ambulatory children with mild spastic CP and typically developing children (4 to 11 years; 12/group) were tested. Magnetic resonance imaging was used to estimate cortical, medullary and total bone volume and width, bone strength [i.e., section modulus (Z) and polar moment of inertia (J)], and bone marrow fat concentration in the midtibia, and muscle volume, intermuscular, subfascial, and subcutaneous adipose tissue (AT) volume and intramuscular fat concentration in the midleg. Physical activity monitors worn on the ankle were used to assess physical activity. Results There were no group differences in age, height, body mass, body mass percentile, BMI, BMI percentile or tibia length, but children with CP had lower height percentile (19th vs. 50th percentile) and total physical activity counts (44 %) than controls (both p < 0.05). Children with CP also had lower cortical volume (30 %), cortical width in the posterior (16 %) and medial (32 %) portion of the shaft, total bone width in the medial-lateral direction (15 %), Z in the medial-lateral direction (34 %), J (39 %) and muscle volume (39 %), and higher bone marrow fat concentration (82.1 ± 1.8 % vs. 80.5 ± 1.9 %), subfascial AT volume (3.3 fold) and intramuscular fat concentration (25.0 ± 8.0 % vs. 16.1 ± 3.3 %) than controls (all p < 0.05). When tibia length was statistically controlled, all group differences in bone architecture, bone strength, muscle volume and fat infiltration estimates, except posterior cortical width, were still present (all p < 0.05). Furthermore, a higher intermuscular AT volume in children with CP compared to

Freeze-Dried Platelet-Rich Plasma Accelerates Bone Union with Adequate Rigidity in Posterolateral Lumbar Fusion Surgery Model in Rats

NASA Astrophysics Data System (ADS)

Shiga, Yasuhiro; Orita, Sumihisa; Kubota, Go; Kamoda, Hiroto; Yamashita, Masaomi; Matsuura, Yusuke; Yamauchi, Kazuyo; Eguchi, Yawara; Suzuki, Miyako; Inage, Kazuhide; Sainoh, Takeshi; Sato, Jun; Fujimoto, Kazuki; Abe, Koki; Kanamoto, Hirohito; Inoue, Masahiro; Kinoshita, Hideyuki; Aoki, Yasuchika; Toyone, Tomoaki; Furuya, Takeo; Koda, Masao; Takahashi, Kazuhisa; Ohtori, Seiji

2016-11-01

Fresh platelet-rich plasma (PRP) accelerates bone union in rat model. However, fresh PRP has a short half-life. We suggested freeze-dried PRP (FD-PRP) prepared in advance and investigated its efficacy in vivo. Spinal posterolateral fusion was performed on 8-week-old male Sprague-Dawley rats divided into six groups based on the graft materials (n = 10 per group): sham control, artificial bone (A hydroxyapatite-collagen composite) -alone, autologous bone, artificial bone + fresh-PRP, artificial bone + FD-PRP preserved 8 weeks, and artificial bone + human recombinant bone morphogenetic protein 2 (BMP) as a positive control. At 4 and 8 weeks after the surgery, we investigated their bone union-related characteristics including amount of bone formation, histological characteristics of trabecular bone at remodeling site, and biomechanical strength on 3-point bending. Comparable radiological bone union was confirmed at 4 weeks after surgery in 80% of the FD-PRP groups, which was earlier than in other groups (p < 0.05). Histologically, the trabecular bone had thinner and more branches in the FD-PRP. Moreover, the biomechanical strength was comparable to that of autologous bone. FD-PRP accelerated bone union at a rate comparable to that of fresh PRP and BMP by remodeling the bone with thinner, more tangled, and rigid trabecular bone.

Freeze-Dried Platelet-Rich Plasma Accelerates Bone Union with Adequate Rigidity in Posterolateral Lumbar Fusion Surgery Model in Rats

PubMed Central

Shiga, Yasuhiro; Orita, Sumihisa; Kubota, Go; Kamoda, Hiroto; Yamashita, Masaomi; Matsuura, Yusuke; Yamauchi, Kazuyo; Eguchi, Yawara; Suzuki, Miyako; Inage, Kazuhide; Sainoh, Takeshi; Sato, Jun; Fujimoto, Kazuki; Abe, Koki; Kanamoto, Hirohito; Inoue, Masahiro; Kinoshita, Hideyuki; Aoki, Yasuchika; Toyone, Tomoaki; Furuya, Takeo; Koda, Masao; Takahashi, Kazuhisa; Ohtori, Seiji

2016-01-01

Fresh platelet-rich plasma (PRP) accelerates bone union in rat model. However, fresh PRP has a short half-life. We suggested freeze-dried PRP (FD-PRP) prepared in advance and investigated its efficacy in vivo. Spinal posterolateral fusion was performed on 8-week-old male Sprague-Dawley rats divided into six groups based on the graft materials (n = 10 per group): sham control, artificial bone (A hydroxyapatite–collagen composite) –alone, autologous bone, artificial bone + fresh-PRP, artificial bone + FD-PRP preserved 8 weeks, and artificial bone + human recombinant bone morphogenetic protein 2 (BMP) as a positive control. At 4 and 8 weeks after the surgery, we investigated their bone union–related characteristics including amount of bone formation, histological characteristics of trabecular bone at remodeling site, and biomechanical strength on 3-point bending. Comparable radiological bone union was confirmed at 4 weeks after surgery in 80% of the FD-PRP groups, which was earlier than in other groups (p < 0.05). Histologically, the trabecular bone had thinner and more branches in the FD-PRP. Moreover, the biomechanical strength was comparable to that of autologous bone. FD-PRP accelerated bone union at a rate comparable to that of fresh PRP and BMP by remodeling the bone with thinner, more tangled, and rigid trabecular bone. PMID:27833116

Insufficient irrigation induces peri-implant bone resorption: an in vivo histologic analysis in sheep.

PubMed

Trisi, Paolo; Berardini, Marco; Falco, Antonello; Podaliri Vulpiani, Michele; Perfetti, Giorgio

2014-06-01

To measure in vivo impact of dense bone overheating on implant osseointegration and peri-implant bone resorption comparing different bur irrigation methods vs. no irrigation. Twenty TI-bone implants were inserted in the inferior edge of mandibles of sheep. Different cooling procedures were used in each group: no irrigation (group A), only internal bur irrigation (group B), both internal and external irrigation (group C), and external irrigation (group D). The histomorphometric parameters calculated for each implant were as follows: %cortical bone-implant contact (%CBIC) and %cortical bone volume (%CBV). Friedman's test was applied to test the statistical differences. In group A, we found a huge resorption of cortical bone with %CBIC and %CBV values extremely low. Groups B and C showed mean %CBIC and %BV values higher than other groups The mean %CBV value was significantly different when comparing group B and group C vs. group A (P < 0.05). Significant differences in %CBIC were found also between group C and group A (P < 0.05). Thermal injury, due to insufficient irrigation, of hard bone caused massive resorption of the cortical bone and implant failure. Drilling procedures on hard bone need an adequate cooling supply because the bone matrix overheating may induce complete resorption of dense bone around implants. Internal-external irrigation and only internal irrigation showed to be more efficient than other types of cooling methods in preventing bone resorption around implants. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

Comparison of Bone Grafts From Various Donor Sites in Human Bone Specimens.

PubMed

Kamal, Mohammad; Gremse, Felix; Rosenhain, Stefanie; Bartella, Alexander K; Hölzle, Frank; Kessler, Peter; Lethaus, Bernd

2018-05-14

The objective of the current study was to compare the three-dimensional (3D) morphometric microstructure in human cadaveric bone specimens taken from various commonly utilized donor sites for autogenous bone grafting. Autogenous bone grafts can be harvested from various anatomic sites and express heterogeneous bone quality with a specific 3D microstructure for each site. The long-term structural integrity and susceptibility to resorption of the graft depend on the selected donor bone. Micro-computed tomography generates high-resolution datasets of bone structures and calcifications making this modality versatile for microarchitecture analysis and quantification of the bone. Six bone specimens, 10 mm in length, where anatomically possible, were obtained from various anatomical sites from 10 human dentate cadavers (4 men, 6 women, mean age 69.5 years). Specimens were scanned using a micro-computed tomography device and volumetrically reconstructed. A virtual cylindrical inclusion was reconstructed to analyze the bone mineral density and structural morphometric analysis using bone indices: relative bone volume, surface density, trabecular thicknesses, and trabecular separation. Calvarial bone specimens showed the highest mineral density, followed by the chin, then mandibular ramus then the tibia, whereas iliac crest and maxillary tuberosity had lower bone mineral densities. The pairwise comparison revealed statistically significant differences in the bone mineral density and relative bone volume index in the calvaria, mandibular ramus, mandibular symphysis groups when compared with those in the iliac crest and maxillary tuberosity, suggesting higher bone quality in the former groups than in the latter; tibial specimens expressed variable results.

Bone mineral density across a range of physical activity volumes: NHANES 2007-2010.

PubMed

Whitfield, Geoffrey P; Kohrt, Wendy M; Pettee Gabriel, Kelley K; Rahbar, Mohammad H; Kohl, Harold W

2015-02-01

The association between aerobic physical activity volume and bone mineral density (BMD) is not completely understood. The purpose of this study was to clarify the association between BMD and aerobic activity across a broad range of activity volumes, particularly volumes between those recommended in the 2008 Physical Activity Guidelines for Americans and those of trained endurance athletes. Data from the 2007-2010 National Health and Nutrition Examination Survey were used to quantify the association between reported physical activity and BMD at the lumbar spine and proximal femur across the entire range of activity volumes reported by US adults. Participants were categorized into multiples of the minimum guideline-recommended volume based on reported moderate- and vigorous-intensity leisure activity. Lumbar and proximal femur BMD were assessed with dual-energy x-ray absorptiometry. Among women, multivariable-adjusted linear regression analyses revealed no significant differences in lumbar BMD across activity categories, whereas proximal femur BMD was significantly higher among those who exceeded the guidelines by 2-4 times than those who reported no activity. Among men, multivariable-adjusted BMD at both sites neared its highest values among those who exceeded the guidelines by at least 4 times and was not progressively higher with additional activity. Logistic regression estimating the odds of low BMD generally echoed the linear regression results. The association between physical activity volume and BMD is complex. Among women, exceeding guidelines by 2-4 times may be important for maximizing BMD at the proximal femur, whereas among men, exceeding guidelines by ≥4 times may be beneficial for lumbar and proximal femur BMD.

Pullout strength of cancellous screws in human femoral heads depends on applied insertion torque, trabecular bone microarchitecture and areal bone mineral density.

PubMed

Ab-Lazid, Rosidah; Perilli, Egon; Ryan, Melissa K; Costi, John J; Reynolds, Karen J

2014-12-01

For cancellous bone screws, the respective roles of the applied insertion torque (TInsert) and of the quality of the host bone (microarchitecture, areal bone mineral density (aBMD)), in contributing to the mechanical holding strength of the bone-screw construct (FPullout), are still unclear. During orthopaedic surgery screws are tightened, typically manually, until adequate compression is attained, depending on surgeons' manual feel. This corresponds to a subjective insertion torque control, and can lead to variable levels of tightening, including screw stripping. The aim of this study, performed on cancellous screws inserted in human femoral heads, was to investigate which, among the measurements of aBMD, bone microarchitecture, and the applied TInsert, has the strongest correlation with FPullout. Forty six femoral heads were obtained, over which microarchitecture and aBMD were evaluated using micro-computed tomography and dual X-ray absorptiometry. Using an automated micro-mechanical test device, a cancellous screw was inserted in the femoral heads at TInsert set to 55% to 99% of the predicted stripping torque beyond screw head contact, after which FPullout was measured. FPullout exhibited strongest correlations with TInsert (R=0.88, p<0.001), followed by structure model index (SMI, R=-0.81, p<0.001), bone volume fraction (BV/TV, R=0.73, p<0.001) and aBMD (R=0.66, p<0.01). Combinations of TInsert with microarchitectural parameters and/or aBMD did not improve the prediction of FPullout. These results indicate that, for cancellous screws, FPullout depends most strongly on the applied TInsert, followed by microarchitecture and aBMD of the host bone. In trabecular bone, screw tightening increases the holding strength of the screw-bone construct. Copyright © 2014 Elsevier Ltd. All rights reserved.

Induced wettability and surface-volume correlation of composition for bovine bone derived hydroxyapatite particles

NASA Astrophysics Data System (ADS)

Maidaniuc, Andreea; Miculescu, Florin; Voicu, Stefan Ioan; Andronescu, Corina; Miculescu, Marian; Matei, Ecaterina; Mocanu, Aura Catalina; Pencea, Ion; Csaki, Ioana; Machedon-Pisu, Teodor; Ciocan, Lucian Toma

2018-04-01

Hydroxyapatite powders characteristics need to be determined both for quality control purposes and for a proper control of microstructural features of bone reconstruction products. This study combines bulk morphological and compositional analysis methods (XRF, SEM-EDS, FT-IR) with surface-related methods (XPS, contact angle measurements) in order to correlate the characteristics of hydroxyapatite powders derived from bovine bone for its use in medical applications. An experimental approach for correlating the surface and volume composition was designed based on the analysis depth of each spectral method involved in the study. Next, the influences of powder particle size and forming method on the contact angle between water drops and ceramic surface were evaluated for identifying suitable strategies of tuning hydroxyapatite's wettability. The results revealed a preferential arrangement of chemical elements at the surface of hydroxyapatite particles which could induce a favourable material behaviour in terms of sinterability and biological performance.

Bone density and anisotropy affect periprosthetic cement and bone stresses after anatomical glenoid replacement: A micro finite element analysis.

PubMed

Chevalier, Yan; Santos, Inês; Müller, Peter E; Pietschmann, Matthias F

2016-06-14

Glenoid loosening is still a main complication for shoulder arthroplasty. We hypothesize that cement and bone stresses potentially leading to fixation failure are related not only to glenohumeral conformity, fixation design or eccentric loading, but also to bone volume fraction, cortical thickness and degree of anisotropy in the glenoid. In this study, periprosthetic bone and cement stresses were computed with micro finite element models of the replaced glenoid depicting realistic bone microstructure. These models were used to quantify potential effects of bone microstructural parameters under loading conditions simulating different levels of glenohumeral conformity and eccentric loading simulating glenohumeral instability. Results show that peak cement stresses were achieved near the cement-bone interface in all loading schemes. Higher stresses within trabecular bone tissue and cement mantle were obtained within specimens of lower bone volume fraction and in regions of low anisotropy, increasing with decreasing glenohumeral conformity and reaching their maxima below the keeled design when the load is shifted superiorly. Our analyses confirm the combined influences of eccentric load shifts with reduced bone volume fraction and anisotropy on increasing periprosthetic stresses. They finally suggest that improving fixation of glenoid replacements must reduce internal cement and bone tissue stresses, in particular in glenoids of low bone density and heterogeneity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Tissue-engineered bone constructed in a bioreactor for repairing critical-sized bone defects in sheep.

PubMed

Li, Deqiang; Li, Ming; Liu, Peilai; Zhang, Yuankai; Lu, Jianxi; Li, Jianmin

2014-11-01

Repair of bone defects, particularly critical-sized bone defects, is a considerable challenge in orthopaedics. Tissue-engineered bones provide an effective approach. However, previous studies mainly focused on the repair of bone defects in small animals. For better clinical application, repairing critical-sized bone defects in large animals must be studied. This study investigated the effect of a tissue-engineered bone for repairing critical-sized bone defect in sheep. A tissue-engineered bone was constructed by culturing bone marrow mesenchymal-stem-cell-derived osteoblast cells seeded in a porous β-tricalcium phosphate ceramic (β-TCP) scaffold in a perfusion bioreactor. A critical-sized bone defect in sheep was repaired with the tissue-engineered bone. At the eighth and 16th week after the implantation of the tissue-engineered bone, X-ray examination and histological analysis were performed to evaluate the defect. The bone defect with only the β-TCP scaffold served as the control. X-ray showed that the bone defect was successfully repaired 16 weeks after implantation of the tissue-engineered bone; histological sections showed that a sufficient volume of new bones formed in β-TCP 16 weeks after implantation. Eight and 16 weeks after implantation, the volume of new bones that formed in the tissue-engineered bone group was more than that in the β-TCP scaffold group (P < 0.05). Tissue-engineered bone improved osteogenesis in vivo and enhanced the ability to repair critical-sized bone defects in large animals.

Optimizing Biomaterials for Tissue Engineering Human Bone Using Mesenchymal Stem Cells.

PubMed

Weinand, Christian; Neville, Craig M; Weinberg, Eli; Tabata, Yasuhiko; Vacanti, Joseph P

2016-03-01

Adequate biomaterials for tissue engineering bone and replacement of bone in clinical settings are still being developed. Previously, the combination of mesenchymal stem cells in hydrogels and calcium-based biomaterials in both in vitro and in vivo experiments has shown promising results. However, results may be optimized by careful selection of the material combination. β-Tricalcium phosphate scaffolds were three-dimensionally printed with five different hydrogels: collagen I, gelatin, fibrin glue, alginate, and Pluronic F-127. The scaffolds had eight channels, running throughout the entire scaffold, and macropores. Mesenchymal stem cells (2 × 10) were mixed with each hydrogel, and cell/hydrogel mixes were dispersed onto the corresponding β-tricalcium phosphate/hydrogel scaffold and cultured under dynamic-oscillating conditions for 6 weeks. Specimens were harvested at 1, 2, 4, and 6 weeks and evaluated histologically, radiologically, biomechanically and, at 6 weeks, for expression of bone-specific proteins by reverse-transcriptase polymerase chain reaction. Statistical correlation analysis was performed between radiologic densities in Hounsfield units and biomechanical stiffness. Collagen I samples had superior bone formation at 6 weeks as demonstrated by volume computed tomographic scanning, with densities of 300 HU, similar to native bone, and the highest compression values. Bone specificity of new tissue was confirmed histologically and by the expression of alkaline phosphatase, osteonectin, osteopontin, and osteocalcin. The bone density correlated closely with histologic and biomechanical testing results. Bone formation is supported best by β-tricalcium phosphate/collagen I hydrogel and mesenchymal stem cells in collagen I hydrogel. Therapeutic, V.

Effect of cisplatin on bone transport osteogenesis in dogs.

PubMed

Ehrhart, Nicole; Eurell, Jo Ann C; Tommasini, Matteo; Constable, Peter D; Johnson, Ann L; Feretti, Antonio

2002-05-01

To document effects of cisplatin on regenerate bone formation during the distraction and consolidation phases of bone transport osteogenesis. 10 skeletally mature hounds. Bone transport osteogenesis was performed to reconstruct a 3-cm defect in the radius of each dog. Five dogs were randomly selected to receive cisplatin (70 mg/m2, IV, q 21 d for 4 cycles), and 5 were administered saline (0.9% NaCl) solution. Bone mineral density was measured by use of dual-energy x-ray absorptiometry (DEXA) on days 24, 55, and 90 after surgery. Dogs were euthanatized 90 days after surgery. Histomorphometry was performed on nondecalcified sections of regenerate bone. Bone mineral density and histomorphometric indices of newly formed bone were compared between groups. Densitometric differences in regenerate bone mineral density were not detected between groups at any time period. Cisplatin-treated dogs had decreased mineralized bone volume, decreased percentage of woven bone volume, decreased percentage of osteoblast-covered bone, increased porosity, and increased percentage of osteoblast-covered surfaces, compared with values for control dogs. Lamellar bone volume and osteoid volume did not differ significantly between groups. Regenerate bone will form and remodel during administration of cisplatin. Results of histomorphometric analysis suggest that bone formation and resorption may be uncoupled in cisplatin-treated regenerate bone as a result of increased osteoclast activity or delayed secondary bone formation during remodeling. These histomorphometric differences were modest in magnitude and did not result in clinically observable complications or decreased bone mineral density as measured by use of DEXA.

Bone Metabolism on ISS Missions

NASA Technical Reports Server (NTRS)

Smith, S. M.; Heer, M. A.; Shackelford, L. C.; Zwart, S. R.

2014-01-01

Spaceflight-induced bone loss is associated with increased bone resorption (1, 2), and either unchanged or decreased rates of bone formation. Resistive exercise had been proposed as a countermeasure, and data from bed rest supported this concept (3). An interim resistive exercise device (iRED) was flown for early ISS crews. Unfortunately, the iRED provided no greater bone protection than on missions where only aerobic and muscular endurance exercises were available (4, 5). In 2008, the Advanced Resistive Exercise Device (ARED), a more robust device with much greater resistance capability, (6, 7) was launched to the ISS. Astronauts who had access to ARED, coupled with adequate energy intake and vitamin D status, returned from ISS missions with bone mineral densities virtually unchanged from preflight (7). Bone biochemical markers showed that while the resistive exercise and adequate energy consumption did not mitigate the increased bone resorption, bone formation was increased (7, 8). The typical drop in circulating parathyroid hormone did not occur in ARED crewmembers. In 2014, an updated look at the densitometry data was published. This study confirmed the initial findings with a much larger set of data. In 42 astronauts (33 male, 9 female), the bone mineral density response to flight was the same for men and women (9), and those with access to the ARED did not have the typical decrease in bone mineral density that was observed in early ISS crewmembers with access to the iRED (Figure 1) (7). Biochemical markers of bone formation and resorption responded similarly in men and women. These data are encouraging, and represent the first in-flight evidence in the history of human space flight that diet and exercise can maintain bone mineral density on long-duration missions. However, the maintenance of bone mineral density through bone remodeling, that is, increases in both resorption and formation, may yield a bone with strength characteristics different from those

[Correlation analysis of cement leakage with volume ratio of intravertebral bone cement to vertebral body and vertebral body wall incompetence in percutaneous vertebroplasty for osteoporotic vertebral compression fractures].

PubMed

Liang, De; Ye, Linqiang; Jiang, Xiaobing; Huang, Weiquan; Yao, Zhensong; Tang, Yongchao; Zhang, Shuncong; Jin, Daxiang

2014-11-01

To investigate the risk factors of cement leakage in percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fracture (OVCF). Between March 2011 and March 2012, 98 patients with single level OVCF were treated by PVP, and the clinical data were analyzed retrospectively. There were 13 males and 85 females, with a mean age of 77.2 years (range, 54-95 years). The mean disease duration was 43 days (range, 15-120 days), and the mean T score of bone mineral density (BMD) was -3.8 (range, -6.7- -2.5). Bilateral transpedicular approach was used in all the patients. The patients were divided into cement leakage group and no cement leakage group by occurrence of cement leakage based on postoperative CT. Single factor analysis was used to analyze the difference between 2 groups in T score of BMD, operative level, preoperative anterior compression degree of operative vertebrae, preoperative middle compression degree of operative vertebrae, preoperative sagittal Cobb angle of operative vertebrae, preoperative vertebral body wall incompetence, cement volume, and volume ratio of intravertebral bone cement to vertebral body. All relevant factors were introduced to logistic regression analysis to analyze the risk factors of cement leakage. All procedures were performed successfully. The mean operation time was 40 minutes (range, 30-50 minutes), and the mean volume ratio of intravertebral bone cement to vertebral body was 24.88% (range, 7.84%-38.99%). Back pain was alleviated significantly in all the patients postoperatively. All patients were followed up with a mean time of 8 months (range, 6-12 months). Cement leakage occurred in 49 patients. Single factor analysis showed that there were significant differences in the volume ratio of intravertebral bone cement to vertebral body and preoperative vertebral body wall incompetence between 2 groups (P < 0.05), while no significant difference in T score of BMD, operative level, preoperative anterior compression degree of

Overexpression of bone sialoprotein leads to an uncoupling of bone formation and bone resorption in mice.

PubMed

Valverde, Paloma; Zhang, Jin; Fix, Amanda; Zhu, Ji; Ma, Wenli; Tu, Qisheng; Chen, Jake

2008-11-01

The purpose of this study was to determine the effects of bone sialoprotein (BSP) overexpression in bone metabolism in vivo by using a homozygous transgenic mouse line that constitutively overexpresses mouse BSP cDNA driven by the cytomegalovirus (CMV) promoter. CMV-BSP transgenic (TG) mice and wildtype mice were weighed, and their length, BMD, and trabecular bone volume were measured. Serum levels of RANKL, osteocalcin, osteoprotegerin (OPG), TRACP5b, and PTH were determined. Bone histomorphometry, von Kossa staining, RT-PCR analysis, Western blot, MTS assay, in vitro mineralization assay, and TRACP staining were also performed to delineate phenotypes of this transgenic mouse line. Compared with wildtype mice, adult TG mice exhibit mild dwarfism, lower values of BMD, and lower trabecular bone volume. TG mice serum contained increased calcium levels and decreased PTH levels, whereas the levels of phosphorus and magnesium were within normal limits. TG mice serum also exhibited lower levels of osteoblast differentiation markers and higher levels of markers, indicating osteoclastic activity and bone resorption. H&E staining, TRACP staining, and bone histomorphometry showed that adult TG bones were thinner and the number of giant osteoclasts in TG mice was higher, whereas there were no significant alterations in osteoblast numbers between TG mice and WT mice. Furthermore, the vertical length of the hypertrophic zone in TG mice was slightly enlarged. Moreover, ex vivo experiments indicated that overexpression of BSP decreased osteoblast population and increased osteoclastic activity. Partly because of its effects in enhancing osteoclastic activity and decreasing osteoblast population, BSP overexpression leads to an uncoupling of bone formation and resorption, which in turn results in osteopenia and mild dwarfism in mice. These findings are expected to help the development of therapies to metabolic bone diseases characterized by high serum level of BSP.

Overexpression of Bone Sialoprotein Leads to an Uncoupling of Bone Formation and Bone Resorption in Mice

PubMed Central

Valverde, Paloma; Zhang, Jin; Fix, Amanda; Zhu, Ji; Ma, Wenli; Tu, Qisheng; Chen, Jake

2008-01-01

The purpose of this study was to determine the effects of bone sialoprotein (BSP) overexpression in bone metabolism in vivo by using a homozygous transgenic mouse line that constitutively overexpresses mouse BSP cDNA driven by the cytomegalovirus (CMV) promoter. CMV-BSP transgenic (TG) mice and wildtype mice were weighed, and their length, BMD, and trabecular bone volume were measured. Serum levels of RANKL, osteocalcin, osteoprotegerin (OPG), TRACP5b, and PTH were determined. Bone histomorphometry, von Kossa staining, RT-PCR analysis, Western blot, MTS assay, in vitro mineralization assay, and TRACP staining were also performed to delineate phenotypes of this transgenic mouse line. Compared with wildtype mice, adult TG mice exhibit mild dwarfism, lower values of BMD, and lower trabecular bone volume. TG mice serum contained increased calcium levels and decreased PTH levels, whereas the levels of phosphorus and magnesium were within normal limits. TG mice serum also exhibited lower levels of osteoblast differentiation markers and higher levels of markers, indicating osteoclastic activity and bone resorption. H&E staining, TRACP staining, and bone histomorphometry showed that adult TG bones were thinner and the number of giant osteoclasts in TG mice was higher, whereas there were no significant alterations in osteoblast numbers between TG mice and WT mice. Furthermore, the vertical length of the hypertrophic zone in TG mice was slightly enlarged. Moreover, ex vivo experiments indicated that overexpression of BSP decreased osteoblast population and increased osteoclastic activity. Partly because of its effects in enhancing osteoclastic activity and decreasing osteoblast population, BSP overexpression leads to an uncoupling of bone formation and resorption, which in turn results in osteopenia and mild dwarfism in mice. These findings are expected to help the development of therapies to metabolic bone diseases characterized by high serum level of BSP. PMID:18597627

Programmed administration of parathyroid hormone increases bone formation and reduces bone loss in hindlimb-unloaded ovariectomized rats

NASA Technical Reports Server (NTRS)

Turner, R. T.; Evans, G. L.; Cavolina, J. M.; Halloran, B.; Morey-Holton, E.

1998-01-01

Gonadal insufficiency and reduced mechanical usage are two important risk factors for osteoporosis. The beneficial effects of PTH therapy to reverse the estrogen deficiency-induced bone loss in the laboratory rat are well known, but the influence of mechanical usage in this response has not been established. In this study, the effects of programed administration of PTH on cancellous bone volume and turnover at the proximal tibial metaphysis were determined in hindlimb-unloaded, ovariectomized (OVX), 3-month-old Sprague-Dawley rats. PTH was administered to weight-bearing and hindlimb-unloaded OVX rats with osmotic pumps programed to deliver 20 microg human PTH (approximately 80 microg/kg x day) during a daily 1-h infusion for 7 days. Compared with sham-operated rats, OVX increased longitudinal and radial bone growth, increased indexes of cancellous bone turnover, and resulted in net resorption of cancellous bone. Hindlimb unloading of OVX rats decreased longitudinal and radial bone growth, decreased osteoblast number, increased osteoclast number, and resulted in a further decrease in cancellous bone volume compared with those in weight-bearing OVX rats. Programed administration of PTH had no effect on either radial or longitudinal bone growth in weight-bearing and hindlimb-unloaded OVX rats. PTH treatment had dramatic effects on selected cancellous bone measurements; PTH maintained cancellous bone volume in OVX weight-bearing rats and greatly reduced cancellous bone loss in OVX hindlimb-unloaded rats. In the latter animals, PTH treatment prevented the hindlimb unloading-induced reduction in trabecular thickness, but the hormone was ineffective in preventing either the increase in osteoclast number or the loss of trabecular plates. Importantly, PTH treatment increased the retention of a baseline flurochrome label, osteoblast number, and bone formation in the proximal tibial metaphysis regardless of the level of mechanical usage. These findings demonstrate that

Hake fish bone as a calcium source for efficient bone mineralization.

PubMed

Flammini, Lisa; Martuzzi, Francesca; Vivo, Valentina; Ghirri, Alessia; Salomi, Enrico; Bignetti, Enrico; Barocelli, Elisabetta

2016-01-01

Calcium is recognized as an essential nutritional factor for bone health. An adequate intake is important to achieve or maintain optimal bone mass in particular during growth and old age. The aim of the present study was to evaluate the efficiency of hake fish bone (HBF) as a calcium source for bone mineralization: in vitro on osteosarcoma SaOS-2 cells, cultured in Ca-free osteogenic medium (OM) and in vivo on young growing rats fed a low-calcium diet. Lithotame (L), a Ca supplement derived from Lithothamnium calcareum, was used as control. In vitro experiments showed that HBF supplementation provided bone mineralization similar to standard OM, whereas L supplementation showed lower activity. In vivo low-Ca HBF-added and L-added diet similarly affected bone deposition. Physico-chemical parameters concerning bone mineralization, such as femur breaking force, tibia density and calcium/phosphorus mineral content, had beneficial effects from both Ca supplementations, in the absence of any evident adverse effect. We conclude HBF derived from by-product from the fish industry is a good calcium supplier with comparable efficacy to L.

Unicameral bone cyst of the calcaneus - minimally invasive endoscopic surgical treatment. Case report.

PubMed

Stoica, Ioan Cristian; Pop, Doina Mihaela; Grosu, Florin

2017-01-01

The role of arthroscopic surgery for the treatment of various orthopedic pathologies has greatly improved during the last years. Recent publications showed that benign bone lesion may benefit from this minimally invasive surgical method, in order to minimize the invasiveness and the period of immobilization and to increase visualization. Unicameral bone cysts may be adequately treated by minimally invasive endoscopic surgery. The purpose of the current paper is to present the case report of a patient with a unicameral bone cyst of the calcaneus that underwent endoscopically assisted treatment with curettage and bone grafting with allograft from a bone bank, with emphasis on the surgical technique. Unicameral bone cyst is a benign bone lesion, which can be adequately treated by endoscopic curettage and percutaneous injection of morselized bone allograft in symptomatic patients.

Multiple Perforations of the Sinus Floor During Maxillary Sinus Floor Augmentation to Provide Access to the Bone Marrow Space: A Technical Report.

PubMed

Ulm, Christian; Bertl, Kristina; Strbac, Georg D; Esfandeyari, Azadeh; Stavropoulos, Andreas; Zechner, Werner

2017-12-01

Sinus floor augmentation is a routinely used surgical technique for increasing the bone height/volume of the atrophic posterior maxilla. Optimal integration of the implanted augmentation material within the newly formed bone will-at least partly-depend on adequate vascularization to ensure sufficient recruitment of osteoblast and osteoclast precursor cells. The present technical note describes a modification intended to facilitate increased blood inflow into the augmented space. After preparation of the lateral window and elevation of the Schneiderian membrane, the cortical bone of the sinus floor is perforated several times either by using a piezoelectric device or a microsurgical handpiece with the corresponding tip or bur; these perforations should extend into the trabecular bone. The experiences with this modified technique after 12 patients are presented and discussed. It is expected that by means of this relatively simple technique, increased blood and cell inflow into the augmented space is achieved. This may, in turn, enhance new bone formation and improve the integration of the augmentation material.

Metabolic bone disease in chronic renal failure. II. Renal transplant patients.

PubMed Central

Huffer, W. E.; Kuzela, D.; Popovtzer, M. M.; Starzl, T. E.

1975-01-01

Trabecular vertebral bone of renal transplant patients was quantitatively compared with bone from normal individuals and dialyzed and nondialyzed patienets with chronic renal failure reported in detail in an earlier study. Long- and short-term transplant patients have increased bone resorption and mineralization defects similar to renal osteodystrophy in dialyzed and nondialyzed patients. However, in transplant patients the magnitude of resorption is greater, and bone volume tends to decrease rather than increase. Resorptive activity in transplant patients is maximal during the first year after transplantation. Bone volume decreases continuously for at least 96 months after transplantation. Only decreased bone volume correlated with success or failure of the renal transplant. Morphologic findings in this study correlate with other clinical and morphologic data to suggest that reduction in bone volume in transplant patients results from a combination of persistent hyperparathyroidism and suppression of bone formation by steroid therapy. Images Fig 1 PMID:1091152

Effects of Spaceflight on Bone: The Rat as an Animal Model for Human Bone Loss

NASA Technical Reports Server (NTRS)

Halloran, B.; Weider, T.; Morey-Holton, E.

1999-01-01

The loss of weight bearing during spaceflight results in osteopenia in humans. Decrements in bone mineral reach 3-10% after as little as 75-184 days in space. Loss of bone mineral during flight decreases bone strength and increases fracture risk. The mechanisms responsible for, and the factors contributing to, the changes in bone induced by spaceflight are poorly understood. The rat has been widely used as an animal model for human bone loss during spaceflight. Despite its potential usefulness, the results of bone studies performed in the rat in space have been inconsistent. In some flights bone formation is decreased and cancellous bone volume reduced, while in others no significant changes in bone occur. In June of 1996 Drs. T. Wronski, S. Miller and myself participated in a flight experiment (STS 78) to examine the effects of glucocorticoids on bone during weightlessness. Technically the 17 day flight experiment was flawless. The results, however, were surprising. Cancellous bone volume and osteoblast surface in the proximal tibial metaphysis were the same in flight and ground-based control rats. Normal levels of cancellous bone mass and bone formation were also detected in the lumbar vertebrae and femoral neck of flight rats. Furthermore, periosteal bone formation rate was found to be identical in flight and ground-based control rats. Spaceflight had little or no effect on bone metabolism! These results prompted us to carefully review the changes in bone observed in, and the flight conditions of previous spaceflight missions.

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

NASA Astrophysics Data System (ADS)

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.

Calcium isotope signature: new proxy for net change in bone volume for chronic kidney disease and diabetic rats.

PubMed

Tanaka, Yu-Ki; Yajima, Nobuyuki; Higuchi, Yusuke; Yamato, Hideyuki; Hirata, Takafumi

2017-12-01

Herein, we measure the Ca isotope ratios ( 44 Ca/ 42 Ca and 43 Ca/ 42 Ca) in serum and bone samples collected from rats with chronic kidney disease (CKD) or diabetes mellitus (DM). For the serum samples, the isotope ratios are lower for the CKD (δ 44 Ca/ 42 Ca serum = 0.16 ± 0.11‰; 2SD, n = 6) and the DM (δ 44 Ca/ 42 Ca serum = -0.11 ± 0.25‰; 2SD, n = 7) rats than that for the control rats (δ 44 Ca/ 42 Ca serum = 0.25 ± 0.04‰; 2SD, n = 7). Bone samples from two distinct positions of 20 rats in total, namely, the center and proximal parts of the tibial diaphysis, are subject to Ca isotope analysis. The resulting δ 44 Ca/ 42 Ca values for the bone of the proximal part are about 0.3‰ lower than that for the serum samples from the same rats. The larger isotope fractionations between the serum and bone are consistent with previously reported data for vertebrate animals (e.g., Skulan and DePaolo, 1999), which suggests the preferential incorporation of lighter Ca isotopes through bone formation. For the bones from the control and CKD rats, there were no differences in the δ 44 Ca/ 42 Ca values between the positions of the bone. In contrast, the δ 44 Ca/ 42 Ca values of the bone for the DM rats were different between the positions of the bone. Due to the lower bone turnover rate for the DM rats, the δ 44 Ca/ 42 Ca for the middle of the diaphysis can reflect the Ca isotopes in the bone formed prior to the progression of DM states. Thus, the resulting δ 44 Ca/ 42 Ca values show a clear correlation with bone mineral density (BMD). This can be due to the release of isotopically lighter Ca from the bone to the serum. In the present study, our data demonstrate that the δ 44 Ca/ 42 Ca value for serum can be used as a new biomarker for evaluating changes in bone turnover rate, followed by changes in bone volume.

Probiotics in gut-bone signaling

PubMed Central

Schepper, Jonathan D; Irwin, Regina; Kang, Jun; Dagenais, Kevin; Lemon, Tristan; Shinouskis, Ally; Parameswaran, Narayanan; McCabe, Laura R

2017-01-01

The intestinal environment is linked to an array of conditions and diseases, including osteoporosis. Human and animal studies indicate that probiotics can benefit intestinal health and may provide a useful therapeutic to prevent and/or treat bone loss. Probiotics are defined as live microorganisms that when administered in adequate amounts will confer a health benefit on the host. In this review, we will focus on 1) probiotics (definition, history, nomenclature, types), 2) the effects of probiotics on bone health and 3) mechanisms of probiotic prevention of bone pathologies. PMID:29101658

The Effect of Different Bone Marrow Stimulation Techniques on Human Talar Subchondral Bone: A Micro-Computed Tomography Evaluation.

PubMed

Gianakos, Arianna L; Yasui, Youichi; Fraser, Ethan J; Ross, Keir A; Prado, Marcelo P; Fortier, Lisa A; Kennedy, John G

2016-10-01

To evaluate morphological alterations, microarchitectural disturbances, and the extent of bone marrow access to the subchondral bone marrow compartment using micro-computed tomography analysis in different bone marrow stimulation (BMS) techniques. Nine zones in a 3 × 3 grid pattern were assigned to 5 cadaveric talar dome articular surfaces. A 1.00-mm microfracture awl (s.MFX), a 2.00-mm standard microfracture awl (l.MFX), or a 1.25-mm Kirschner wire (K-wire) drill hole was used to penetrate the subchondral bone in each grid zone. Subchondral bone holes and adjacent tissue areas were assessed by micro-computed tomography to analyze adjacent bone area destruction and communicating channels to the bone marrow. Grades 1 to 3 were assigned, where 1 = minimal compression/sclerosis; 2 = moderate compression/sclerosis; 3 = severe compression/sclerosis. Bone volume/total tissue volume, bone surface area/bone volume, trabecular thickness, and trabecular number were calculated in the region of interest. Visual assessment revealed that the s.MFX had significantly more grade 1 holes (P < .001) and that the l.MFX had significantly more poor/grade 3 holes (P = .002). Bone marrow channel assessment showed a statistically significant increase in the number of channels in the s.MFX when compared with both K-wire and l.MFX holes (P < .001). Bone volume fraction for the s.MFX was significantly less than that of the l.MFX (P = .029). BMS techniques using instruments with larger diameters resulted in increased trabecular compaction and sclerosis in areas adjacent to the defect. K-wire and l.MFX techniques resulted in less open communicating bone marrow channels, denoting a reduction in bone marrow access. The results of this study indicate that BMS using larger diameter devices results in greater microarchitecture disturbances. The current study suggests that the choice of a BMS technique should be carefully considered as the results indicate that smaller diameter hole sizes may

Radiographic comparison of different concentrations of recombinant human bone morphogenetic protein with allogenic bone compared with the use of 100% mineralized cancellous bone allograft in maxillary sinus grafting.

PubMed

Froum, Stuart J; Wallace, Stephen; Cho, Sang-Choon; Khouly, Ismael; Rosenberg, Edwin; Corby, Patricia; Froum, Scott; Mascarenhas, Patrick; Tarnow, Dennis P

2014-01-01

The purpose of this study was to radiographically evaluate, then analyze, bone height, volume, and density with reference to percentage of vital bone after maxillary sinuses were grafted using two different doses of recombinant human bone morphogenetic protein 2/acellular collagen sponge (rhBMP-2/ACS) combined with mineralized cancellous bone allograft (MCBA) and a control sinus grafted with MCBA only. A total of 18 patients (36 sinuses) were used for analysis of height and volume measurements, having two of three graft combinations (one in each sinus): (1) control, MCBA only; (2) test 1, MCBA + 5.6 mL of rhBMP-2/ACS (containing 8.4 mg of rhBMP-2); and (3) test 2, MCBA + 2.8 mL of rhBMP-2/ACS (containing 4.2 mg of rhBMP-2). The study was completed with 16 patients who also had bilateral cores removed 6 to 9 months following sinus augmentation. A computer software system was used to evaluate 36 computed tomography scans. Two time points where selected for measurements of height: The results indicated that height of the grafted sinus was significantly greater in the treatment groups compared with the control. However, by the second time point, there were no statistically significant differences. Three weeks post-surgery bone volume measurements showed similar statistically significant differences between test and controls. However, prior to core removal, test group 1 with the greater dose of rhBMP-2 showed a statistically significant greater increase compared with test group 2 and the control. There was no statistically significant difference between the latter two groups. All three groups had similar volume and shrinkage. Density measurements varied from the above results, with the control showing statistically significant greater density at both time points. By contrast, the density increase over time in both rhBMP groups was similar and statistically higher than in the control group. There were strong associations between height and volume in all groups and

Autogenous bone particle/titanium fiber composites for bone regeneration in a rabbit radius critical-size defect model.

PubMed

Xie, Huanxin; Ji, Ye; Tian, Qi; Wang, Xintao; Zhang, Nan; Zhang, Yicai; Xu, Jun; Wang, Nanxiang; Yan, Jinglong

2017-11-01

To explore the effects of autogenous bone particle/titanium fiber composites on repairing segmental bone defects in rabbits. A model of bilateral radial bone defect was established in 36 New Zealand white rabbits which were randomly divided into 3 groups according to filling materials used for bilaterally defect treatment: in group C, 9 animal bone defect areas were prepared into simple bilateral radius bone defect (empty sham) as the control group; 27 rabbits were used in groups ABP and ABP-Ti. In group ABP, left defects were simply implanted with autogenous bone particles; meanwhile, group ABP-Ti animals had right defects implanted with autogenous bone particle/titanium fiber composites. Animals were sacrificed at 4, 8, and 12 weeks, respectively, after operation. Micro-CT showed that group C could not complete bone regeneration. Bone volume to tissue volume values in group ABP-Ti were better than group ABP. From histology and histomorphometry Groups ABP and ABP-Ti achieved bone repair, the bone formation of group ABP-Ti was better. The mechanical strength of group ABP-Ti was superior to that of other groups. These results confirmed the effectiveness of autologous bone particle/titanium fiber composites for promoting bone regeneration and mechanical strength.

Quantification of osteolytic bone lesions in a preclinical rat trial

NASA Astrophysics Data System (ADS)

Fränzle, Andrea; Bretschi, Maren; Bäuerle, Tobias; Giske, Kristina; Hillengass, Jens; Bendl, Rolf

2013-10-01

In breast cancer, most of the patients who died, have developed bone metastasis as disease progression. Bone metastases in case of breast cancer are mainly bone destructive (osteolytic). To understand pathogenesis and to analyse response to different treatments, animal models, in our case rats, are examined. For assessment of treatment response to bone remodelling therapies exact segmentations of osteolytic lesions are needed. Manual segmentations are not only time-consuming but lack in reproducibility. Computerized segmentation tools are essential. In this paper we present an approach for the computerized quantification of osteolytic lesion volumes using a comparison to a healthy reference model. The presented qualitative and quantitative evaluation of the reconstructed bone volumes show, that the automatically segmented lesion volumes complete missing bone in a reasonable way.

Dietary coral calcium and zeolite protects bone in a mouse model for postmenopausal bone loss.

PubMed

Banu, Jameela; Varela, Erika; Guerra, Juan M; Halade, Ganesh; Williams, Paul J; Bahadur, Ali N; Hanaoka, Kokichi; Fernandes, Gabriel

2012-12-01

In patients diagnosed with osteoporosis, calcium is lost from bones making them weaker and easily susceptible to fractures. Supplementation of calcium is highly recommended for such conditions. However, the source of calcium plays an important role in the amount of calcium that is assimilated into bone. We hypothesize that naturally occurring coral calcium and zeolite may prevent ovariectomy-induced bone loss. We have measured bone loss in ovariectomized mice supplemented with coral calcium and Zeolite. Female C57BL/6 mice were either sham-operated or ovariectomized and fed diets containing coral calcium or zeolite for 6 months. Serum was analyzed for bone biochemical markers and cytokines. Bones were analyzed using dual x-ray absorbtiometry, peripheral quantitative computed tomography, and micro-computed tomography densitometry. In the distal femoral metaphysis, total bone and cortical bone mass was restored and the endocortical surface was significantly decreased in coral calcium and zeolite fed ovariectomized (OVX) mice. Trabecular number and the ratio of bone volume to total volume was higher in OVX mice after coral calcium and zeolite feeding, while trabecular separation decreased in the different treatment OVX groups. Coral calcium protected bone to a lesser extent in the proximal tibia and lumbar vertebrae. Overall, coral calcium and zeolite may protect postmenopausal bone loss. Copyright © 2012 Elsevier Inc. All rights reserved.

SU-E-T-13: A Comparative Dosimetric Study On Radio-Dynamic Therapy for Pelvic Cancer Treatment: Strategies for Bone Marrow Dose and Volume Reduction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, C; Renmin Hospital of Wuhan University, Wuhan, Hubei Province; Wang, B

Purpose: Radio-dynamic therapy (RDT) is a potentially effective modality for local and systemic cancer treatment. Using RDT, the administration of a radio-sensitizer enhances the biological effect of high-energy photons. Although the sensitizer uptake ratio of tumor to normal tissue is normally high, one cannot simply neglect its effect on critical structures. In this study, we aim to explore planning strategies to improve bone marrow sparing without compromising the plan quality for RDT treatment of pelvic cancers. Methods: Ten cervical and ten prostate cancer patients who previously received radiotherapy at our institution were selected for this study. For each patient, ninemore » plans were created using the Varian Eclipse treatmentplanning-system (TPS) with 3D-CRT, IMRT, and VMAT delivery techniques containing various gantry angle combinations and optimization parameters (dose constraints to the bone marrow). To evaluate the plans for bone marrow sparing, the dose-volume parameters V5, V10, V15, V20, V30, and V40 for bone marrow were examined. Effective doseenhancement factors for the sensitizer were used to weigh the dose-volume histograms for various tissues from individual fractions. Results: The planning strategies had different impacts on bone marrow sparing for the cervical and prostate cases. For the cervical cases, provided the bone marrow constraints were properly set during optimization, the dose to bone marrow sparing was found to be comparable between different IMRT and VMAT plans regardless of the gantry angle selection. For the prostate cases, however, careful selection of gantry angles could dramatically improve the bone marrow sparing, although the dose distribution in bone marrow was clinically acceptable for all prostate plans that we created. Conclusion: For intensity-modulated RDT planning for cervical cancer, planners should set bone marrow constraints properly to avoid any adverse damage, while for prostate cancer one can carefully

Freely-available, true-color volume rendering software and cryohistology data sets for virtual exploration of the temporal bone anatomy.

PubMed

Kahrs, Lüder Alexander; Labadie, Robert Frederick

2013-01-01

Cadaveric dissection of temporal bone anatomy is not always possible or feasible in certain educational environments. Volume rendering using CT and/or MRI helps understanding spatial relationships, but they suffer in nonrealistic depictions especially regarding color of anatomical structures. Freely available, nonstained histological data sets and software which are able to render such data sets in realistic color could overcome this limitation and be a very effective teaching tool. With recent availability of specialized public-domain software, volume rendering of true-color, histological data sets is now possible. We present both feasibility as well as step-by-step instructions to allow processing of publicly available data sets (Visible Female Human and Visible Ear) into easily navigable 3-dimensional models using free software. Example renderings are shown to demonstrate the utility of these free methods in virtual exploration of the complex anatomy of the temporal bone. After exploring the data sets, the Visible Ear appears more natural than the Visible Human. We provide directions for an easy-to-use, open-source software in conjunction with freely available histological data sets. This work facilitates self-education of spatial relationships of anatomical structures inside the human temporal bone as well as it allows exploration of surgical approaches prior to cadaveric testing and/or clinical implementation. Copyright © 2013 S. Karger AG, Basel.

Longitudinal Assessment of Synovial, Lymph Node, and Bone Volumes in Inflammatory Arthritis in Mice using in vivo MRI and micro-CT

PubMed Central

Proulx, Steven T.; Kwok, Edmund; You, Zhigang; Papuga, M. Owen; Beck, Christopher A.; Shealy, David J.; Ritchlin, Christopher T.; Awad, Hani A.; Boyce, Brendan F.; Xing, Lianping; Schwarz, Edward M.

2009-01-01

Objective Development of longitudinal 3D outcomes of inflammation and bone erosion in murine arthritis using contrast enhanced (CE) MRI and in vivo micro-CT; and in a pilot study, to determine the value of entrance criteria by age versus synovial volume in therapeutic intervention studies. Methods CE-MRI and in vivo micro-CT was performed on TNF-Tg and WT littermates to quantify the synovial and popliteal lymph node (LN) volumes and patella and talus bone volumes, respectively, which were validated with histology. These longitudinal outcome measures were used to assess the natural history of inflammatory-erosive arthritis. We also performed anti-TNF versus placebo efficacy studies in TNF-Tg mice in which treatment was initiated either by age (4–5 months) or synovial volume (3mm3 as detected by CE-MRI). Linear regression was performed to analyze the correlation between synovitis and focal erosion. Results CE-MRI demonstrated the highly variable nature of TNF-induced joint inflammation. Initiation of treatment by synovial volume produced significantly larger treatment effects on synovial volume (p=0.04) and lymph node volume (p<0.01) than initiation by age. By correlating the MRI and microCT data we were able to demonstrate a significant relationship between changes in synovial and patellar volumes (R2 =0.75; p<0.01). Conclusion In vivo CE-MRI and micro-CT 3D outcome measures are powerful tools that accurately demonstrate the progression of inflammatory-erosive arthritis in mice. These methods can be used to identify mice with arthritis of similar severity before intervention studies are initiated and thus minimize heterogeneity in outcome studies of chronic arthritis seen between genetically identical littermates. PMID:18050199

Bone Mineral Density across a Range of Physical Activity Volumes: NHANES 2007–2010

PubMed Central

Whitfield, Geoffrey P.; Kohrt, Wendy M.; Pettee Gabriel, Kelley K.; Rahbar, Mohammad H.; Kohl, Harold W.

2014-01-01

Introduction The association between aerobic physical activity volume and bone mineral density (BMD) is not completely understood. The purpose of this study was to clarify the association between BMD and aerobic activity across a broad range of activity volumes, in particular volumes between those recommended in the 2008 Physical Activity Guidelines for Americans and those of trained endurance athletes. Methods Data from the 2007–2010 National Health and Nutrition Examination Survey were used to quantify the association between reported physical activity and BMD at the lumbar spine and proximal femur across the entire range of activity volumes reported by US adults. Participants were categorized into multiples of the minimum guideline-recommended volume based on reported moderate and vigorous intensity leisure activity. Lumbar and proximal femur BMD was assessed with dual-energy x-ray absorptiometry. Results Among women, multivariable-adjusted linear regression analyses revealed no significant differences in lumbar BMD across activity categories, while proximal femur BMD was significantly higher among those who exceeded guidelines by 2–4 times than those who reported no activity. Among men, multivariable-adjusted BMD at both sites neared its highest values among those who exceeded guidelines by at least 4 times and was not progressively higher with additional activity. Logistic regression estimating the odds of low BMD generally echoed the linear regression results. Conclusion The association between physical activity volume and BMD is complex. Among women, exceeding guidelines by 2–4 times may be important for maximizing BMD at the proximal femur, while among men, exceeding guidelines by 4+ times may be beneficial for lumbar and proximal femur BMD. PMID:24870584

Local treatment of cancellous bone grafts with BMP-7 and zoledronate increases both the bone formation rate and bone density

PubMed Central

2011-01-01

Background and purpose The remodeling of morselized bone grafts in revision surgery can be enhanced by an anabolic substance such as a bone morphogenetic protein (BMP). On the other hand, BMPs boost catabolism and might cause a premature resorption, both of the graft and of the new-formed bone. Bisphosphonates inactivate osteoclasts and can be used to control the resorption. We studied a combination of both drugs as a local admix to a cancellous allograft. Methods Cancellous bone allografts were harvested and freeze-dried. Either saline, BMP-7, the bisphosphonate zoledronate, or a combination of BMP-7 and zoledronate were added in solution. The grafts were placed in bone conduction chambers and implanted in the proximal tibia of 34 rats. The grafts were harvested after 6 weeks and evaluated by histomorphometry. Results Bone volume/total volume (BV/TV) was 50% in the grafts treated with the combination of BMP-7 and zoledronate and 16% in the saline controls (p < 0.001). In the zoledronate group BV/TV was 56%, and in the BMP group it was 14%. The ingrowth distance of new bone into the graft was 3.5 mm for the combination of BMP-7 and zoledronate and 2.6 mm in the saline control (p = 0.002). The net amount of retained remodeled bone was more than 4 times higher when BMP-7 and zoledronate were combined than in the controls. Interpretation An anabolic drug like BMP-7 can be combined with an anti-catabolic bisphosphonate as local bone graft adjunct, and the combination increases the amount of remaining bone after remodeling is complete. PMID:21434769

A novel method to estimate the volume of bone defects using cone-beam computed tomography: an in vitro study.

PubMed

Esposito, Stefano Andrea; Huybrechts, Bart; Slagmolen, Pieter; Cotti, Elisabetta; Coucke, Wim; Pauwels, Ruben; Lambrechts, Paul; Jacobs, Reinhilde

2013-09-01

The routine use of high-resolution images derived from 3-dimensional cone-beam computed tomography (CBCT) datasets enables the linear measurement of lesions in the maxillary and mandibular bones on 3 planes of space. Measurements on different planes would make it possible to obtain real volumetric assessments. In this study, we tested, in vitro, the accuracy and reliability of new dedicated software developed for volumetric lesion assessment in clinical endodontics. Twenty-seven bone defects were created around the apices of 8 teeth in 1 young bovine mandible to simulate periapical lesions of different sizes and shapes. The volume of each defect was determined by taking an impression of the defect using a silicone material. The samples were scanned using an Accuitomo 170 CBCT (J. Morita Mfg Co, Kyoto, Japan), and the data were uploaded into a newly developed dedicated software tool. Two endodontists acted as independent and calibrated observers. They analyzed each bone defect for volume. The difference between the direct volumetric measurements and the measurements obtained with the CBCT images was statistically assessed using a lack-of-fit test. A correlation study was undertaken using the Pearson product-moment correlation coefficient. Intra- and interobserver agreement was also evaluated. The results showed a good fit and strong correlation between both volume measurements (ρ > 0.9) with excellent inter- and intraobserver agreement. Using this software, CBCT proved to be a reliable method in vitro for the estimation of endodontic lesion volumes in bovine jaws. Therefore, it may constitute a new, validated technique for the accurate evaluation and follow-up of apical periodontitis. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Novel microinjector for carrying bone substitutes for bone regeneration in periodontal diseases.

PubMed

Tsai, Hsiao-Cheng; Li, Yi-Chen; Young, Tai-Horng; Chen, Min-Huey

2016-01-01

Traditionally, guide bone regeneration (GBR) was a widely used method for repairing bone lost from periodontal disease. There were some disadvantages associated with the GBR method, such as the need for a stable barrier membrane and a new creative cavity during the surgical process. To address these disadvantages, the purpose of this study was to evaluate a novel microinjector developed for dental applications. The microinjector was designed to carry bone graft substitutes to restore bone defects for bone regeneration in periodontal diseases. The device would be used to replace the GBR method. In this study, the injected force and ejected volume of substitutes (including air, water, and ethanol) were defined by Hooke's law (n = 3). The optimal particle size of bone graft substitutes was determined by measuring the recycle ratio of bone graft substitutes from the microinjector (n = 3). Furthermore, a novel agarose gel model was used to evaluate the feasibility of the microinjector. The current study found that the injected force was less than 0.4 N for obtaining the ejected volume of approximately 2 mL, and when the particle size of tricalcium phosphate (TCP) was smaller than 0.5 mm, 80% TCP could be ejected from the microinjector. Furthermore, by using an agarose model to simulate the periodontal soft tissue, it was also found that bone graft substitutes could be easily injected into the gel. The results confirmed the feasibility of this novel microinjector for dental applications to carry bone graft substitutes for the restoration of bone defects of periodontal disease. Copyright © 2015. Published by Elsevier B.V.

Microarchitecture of irradiated bone: comparison with healthy bone

NASA Astrophysics Data System (ADS)

Bléry, Pauline; Amouriq, Yves; Guédon, Jeanpierre; Pilet, Paul; Normand, Nicolas; Durand, Nicolas; Espitalier, Florent; Arlicot, Aurore; Malard, Olivier; Weiss, Pierre

2012-03-01

The squamous cell carcinomas of the upper aero-digestive tract represent about ten percent of cancers. External radiation therapy leads to esthetic and functional consequences, and to a decrease of the bone mechanical abilities. For these patients, the oral prosthetic rehabilitation, including possibilities of dental implant placement, is difficult. The effects of radiotherapy on bone microarchitecture parameters are not well known. Thus, the purpose of this study is to assess the effects of external radiation on bone micro architecture in an experimental model of 25 rats using micro CT. 15 rats were irradiated on the hind limbs by a single dose of 20 Grays, and 10 rats were non irradiated. Images of irradiated and healthy bone were compared. Bone microarchitecture parameters (including trabecular thickness, trabecular number, trabecular separation, connectivity density and tissue and bone volume) between irradiated and non-irradiated bones were calculated and compared using a Mann and Whitney test. After 7 and 12 weeks, images of irradiated and healthy bone are different. Differences on the irradiated and the healthy bone populations exhibit a statistical significance. Trabecular number, connectivity density and closed porosity are less important on irradiated bone. Trabecular thickness and separation increase for irradiated bone. These parameters indicate a decrease of irradiated bone properties. Finally, the external irradiation induces changes on the bone micro architecture. This knowledge is of prime importance for better oral prosthetic rehabilitation, including implant placement.

The materials used in bone tissue engineering

NASA Astrophysics Data System (ADS)

Tereshchenko, V. P.; Kirilova, I. A.; Sadovoy, M. A.; Larionov, P. M.

2015-11-01

Bone tissue engineering looking for an alternative solution to the problem of skeletal injuries. The method is based on the creation of tissue engineered bone tissue equivalent with stem cells, osteogenic factors, and scaffolds - the carriers of these cells. For production of tissue engineered bone equivalent is advisable to create scaffolds similar in composition to natural extracellular matrix of the bone. This will provide optimal conditions for the cells, and produce favorable physico-mechanical properties of the final construction. This review article gives an analysis of the most promising materials for the manufacture of cell scaffolds. Biodegradable synthetic polymers are the basis for the scaffold, but it alone cannot provide adequate physical and mechanical properties of the construction, and favorable conditions for the cells. Addition of natural polymers improves the strength characteristics and bioactivity of constructions. Of the inorganic compounds, to create cell scaffolds the most widely used calcium phosphates, which give the structure adequate stiffness and significantly increase its osteoinductive capacity. Signaling molecules do not affect the physico-mechanical properties of the scaffold, but beneficial effect is on the processes of adhesion, proliferation and differentiation of cells. Biodegradation of the materials will help to fulfill the main task of bone tissue engineering - the ability to replace synthetic construct by natural tissues that will restore the original anatomical integrity of the bone.

The materials used in bone tissue engineering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tereshchenko, V. P., E-mail: tervp@ngs.ru; Kirilova, I. A.; Sadovoy, M. A.

Bone tissue engineering looking for an alternative solution to the problem of skeletal injuries. The method is based on the creation of tissue engineered bone tissue equivalent with stem cells, osteogenic factors, and scaffolds - the carriers of these cells. For production of tissue engineered bone equivalent is advisable to create scaffolds similar in composition to natural extracellular matrix of the bone. This will provide optimal conditions for the cells, and produce favorable physico-mechanical properties of the final construction. This review article gives an analysis of the most promising materials for the manufacture of cell scaffolds. Biodegradable synthetic polymers aremore » the basis for the scaffold, but it alone cannot provide adequate physical and mechanical properties of the construction, and favorable conditions for the cells. Addition of natural polymers improves the strength characteristics and bioactivity of constructions. Of the inorganic compounds, to create cell scaffolds the most widely used calcium phosphates, which give the structure adequate stiffness and significantly increase its osteoinductive capacity. Signaling molecules do not affect the physico-mechanical properties of the scaffold, but beneficial effect is on the processes of adhesion, proliferation and differentiation of cells. Biodegradation of the materials will help to fulfill the main task of bone tissue engineering - the ability to replace synthetic construct by natural tissues that will restore the original anatomical integrity of the bone.« less

Mice lacking bone sialoprotein (BSP) lose bone after ovariectomy and display skeletal site-specific response to intermittent PTH treatment.

PubMed

Wade-Gueye, Ndéye Marième; Boudiffa, Maya; Laroche, Norbert; Vanden-Bossche, Arnaud; Fournier, Carole; Aubin, Jane E; Vico, Laurence; Lafage-Proust, Marie-Hélène; Malaval, Luc

2010-11-01

Bone sialoprotein (BSP) belongs to the small integrin-binding ligand, N-linked glycoprotein (SIBLING) family, whose members play multiple and distinct roles in the development, turnover, and mineralization of bone and dentin. The functions of BSP in bone remodeling are not yet well established. We previously showed that BSP knockout (BSP(-/-)) mice exhibit a higher trabecular bone volume, concomitant with lower bone remodeling, than wild-type (BSP(+/+)) mice. To determine whether bone turnover can be stimulated in the absence of BSP, we subjected BSP(+/+) and BSP(-/-) mice to catabolic [ovariectomy (OVX)] or anabolic (intermittent PTH administration) hormonal challenges. BSP(-/-) mice progressively develop hypocalcemia and high serum PTH between 2 and 4 months of age. Fifteen and 30 d after OVX, microtomography analysis showed a significant decrease of trabecular bone volume in tibiae of both genotypes. Histomorphometric parameters of bone formation and resorption were significantly increased by OVX. PTH treatment resulted in an increase of trabecular thickness and both bone formation and resorption parameters at all skeletal sites in both genotypes and a decrease of trabecular bone volume in tibiae of BSP(+/+) but not BSP(-/-) mice. PTH increased cortical thickness and bone area in BSP(+/+) but not BSP(-/-) mice and stimulated the bone formation rate specifically in the endosteum of BSP(+/+) mice and the periosteum of BSP(-/-) mice. PTH enhanced the expression of RANKL, MEPE, and DMP1 in both genotypes but increased OPG and OPN expression only in BSP(-/-) mice. In conclusion, despite the low basal turnover, both catabolic and anabolic challenges increase bone formation and resorption in BSP(-/-) mice, suggesting that compensatory pathways are operative in the skeleton of BSP-deficient mice. Although up-regulation of one or several other SIBLINGs is a possible mechanism, further studies are needed to analyze the interplay and cross-regulation involved in

Three-Dimensional Dynamic Bone Histomorphometry

PubMed Central

Slyfield, C.R.; Tkachenko, E.V.; Wilson, D.L.; Hernandez, C.J.

2011-01-01

Dynamic bone histomorphometry is the standard method for measuring bone remodeling at the level of individual events. While dynamic bone histomorphometry is an invaluable tool for understanding osteoporosis and other metabolic bone diseases, the technique’s two-dimensional nature requires the use of stereology and prevents measures of individual remodeling event number and size. Here, we use a novel three-dimensional fluorescence imaging technique to achieve measures of individual resorption cavities and formation events. We perform this three-dimensional histomorphometry approach using a common model of postmenopausal osteoporosis, the ovariectomized rat. The three-dimensional images demonstrate the spatial relationship between resorption cavities and formation events consistent with the hemi-osteonal model of cancellous bone remodeling. Established ovariectomy was associated with significant increases in the number of resorption cavities per unit bone surface (2.38 ± 0.24 mm−2 SHAM v. 3.86 ± 0.35 mm−2 OVX, mean ± SD, p < 0.05) and total volume occupied by cavities per unit bone volume (0.38 ± 0.06% SHAM v. 1.12 ± 0.18% OVX, p < 0.001), but no difference in surface area per resorption cavity, maximum cavity depth, or cavity volume. Additionally, we find that established ovariectomy is associated with increased size of bone formation events due to merging of formation events (23,700 ± 6,890 μm2 SHAM v. 33,300 ± 7,950 μm2 OVX). No differences in mineral apposition rate (determined in 3D) were associated with established ovariectomy. That established estrogen depletion is associated with increased number of remodeling events with only subtle changes in remodeling event size suggests that circulating estrogens may have their primary effect on the origination of new basic multicellular units with relatively little effect on the progression and termination of active remodeling events. PMID:22028195

The Digital Astronaut Project Computational Bone Remodeling Model (Beta Version) Bone Summit Summary Report

NASA Technical Reports Server (NTRS)

Pennline, James; Mulugeta, Lealem

2013-01-01

Under the conditions of microgravity, astronauts lose bone mass at a rate of 1% to 2% a month, particularly in the lower extremities such as the proximal femur [1-3]. The most commonly used countermeasure against bone loss in microgravity has been prescribed exercise [4]. However, data has shown that existing exercise countermeasures are not as effective as desired for preventing bone loss in long duration, 4 to 6 months, spaceflight [1,3,5,6]. This spaceflight related bone loss may cause early onset of osteoporosis to place the astronauts at greater risk of fracture later in their lives. Consequently, NASA seeks to have improved understanding of the mechanisms of bone demineralization in microgravity in order to appropriately quantify this risk, and to establish appropriate countermeasures [7]. In this light, NASA's Digital Astronaut Project (DAP) is working with the NASA Bone Discipline Lead to implement well-validated computational models to help predict and assess bone loss during spaceflight, and enhance exercise countermeasure development. More specifically, computational modeling is proposed as a way to augment bone research and exercise countermeasure development to target weight-bearing skeletal sites that are most susceptible to bone loss in microgravity, and thus at higher risk for fracture. Given that hip fractures can be debilitating, the initial model development focused on the femoral neck. Future efforts will focus on including other key load bearing bone sites such as the greater trochanter, lower lumbar, proximal femur and calcaneus. The DAP has currently established an initial model (Beta Version) of bone loss due to skeletal unloading in femoral neck region. The model calculates changes in mineralized volume fraction of bone in this segment and relates it to changes in bone mineral density (vBMD) measured by Quantitative Computed Tomography (QCT). The model is governed by equations describing changes in bone volume fraction (BVF), and rates of

Comparison of radiograph-based texture analysis and bone mineral density with three-dimensional microarchitecture of trabecular bone.

PubMed

Ranjanomennahary, P; Ghalila, S Sevestre; Malouche, D; Marchadier, A; Rachidi, M; Benhamou, Cl; Chappard, C

2011-01-01

Hip fracture is a serious health problem and textural methods are being developed to assess bone quality. The authors aimed to perform textural analysis at femur on high-resolution digital radiographs compared to three-dimensional (3D) microarchitecture comparatively to bone mineral density. Sixteen cadaveric femurs were imaged with an x-ray device using a C-MOS sensor. One 17 mm square region of interest (ROI) was selected in the femoral head (FH) and one in the great trochanter (GT). Two-dimensional (2D) textural features from the co-occurrence matrices were extracted. Site-matched measurements of bone mineral density were performed. Inside each ROI, a 16 mm diameter core was extracted. Apparent density (Dapp) and bone volume proportion (BV/TV(Arch)) were measured from a defatted bone core using Archimedes' principle. Microcomputed tomography images of the entire length of the core were obtained (Skyscan 1072) at 19.8 microm of resolution and usual 3D morphometric parameters were computed on the binary volume after calibration from BV/TV(Arch). Then, bone surface/bone volume, trabecular thickness, trabecular separation, and trabecular number were obtained by direct methods without model assumption and the structure model index was calculated. In univariate analysis, the correlation coefficients between 2D textural features and 3D morphological parameters reached 0.83 at the FH and 0.79 at the GT. In multivariate canonical correlation analysis, coefficients of the first component reached 0.95 at the FH and 0.88 at the GT. Digital radiographs, widely available and economically viable, are an alternative method for evaluating bone microarchitectural structure.

An Approach for Determining Quantitative Measures for Bone Volume and Bone Mass in the Pediatric Spina Bifida Population

PubMed Central

Horenstein, Rachel E.; Shefelbine, Sandra J.; Mueske, Nicole M.; Fisher, Carissa L.; Wren, Tishya A.L.

2015-01-01

Background The pediatric spina bifida population suffers from decreased mobility and recurrent fractures. This study aimed to develop a method for quantifying bone mass along the entire tibia in youth with spina bifida. This will provide information about all potential sites of bone deficiencies. Methods Computed tomography images of the tibia for 257 children (n=80 ambulatory spina bifida, n=10 non-ambulatory spina bifida, n=167 typically developing) were analyzed. Bone area was calculated at regular intervals along the entire tibia length and then weighted by calibrated pixel intensity for density weighted bone area. Integrals of density weighted bone area were used to quantify bone mass in the proximal and distal epiphyses and diaphysis. Group differences were evaluated using analysis of variance. Findings Non-ambulatory children suffer from decreased bone mass in the diaphysis and proximal and distal epiphyses compared to ambulatory and control children (P≤0.001). Ambulatory children with spina bifida showed statistically insignificant differences in bone mass in comparison to typically developing children at these sites (P>0.5). Interpretation This method provides insight into tibial bone mass distribution in the pediatric spina bifida population by incorporating information along the whole length of the bone, thereby providing more information than dual-energy x-ray absorptiometry and peripheral quantitative computed tomography. This method can be applied to any population to assess bone mass distribution across the length of any long bone. PMID:26002057

Bone mineralization in childhood and adolescence.

PubMed

Bachrach, L K

1993-08-01

Prevention of osteoporosis depends on establishing adequate peak bone mass in the first two decades of life. Achievement of this goal requires an understanding of factors that promote skeletal health. Genetic factors are important determinants of adult bone mass, but nonheritable variables, including body mass, calcium nutriture, sex steroids, and activity can strongly influence whether maximal bone mineral is achieved. Acquisition of bone mineral continues throughout childhood and adolescence, reaching a lifetime maximum in early adulthood. Adolescence is a particularly critical time for bone mineral accretion as more than half of the bone calcium is normally laid down during the teen years. Chronic illness, malnutrition, or endocrine deficiencies at this age may result in profound deficits in bone mass, which may not be fully reversible. These risk factors contribute to the osteopenia associated with anorexia nervosa, exercise-induced amenorrhea, delayed puberty, Turner's syndrome, and growth hormone deficiency.

Unbiased estimation of the calcaneus volume using the Cavalieri principle on computed tomography images.

PubMed

Acer, N; Bayar, B; Basaloglu, H; Oner, E; Bayar, K; Sankur, S

2008-11-20

The size and shape of tarsal bones are especially relevant when considering some orthopedic diseases such as clubfoot. For this reason, the measurements of the tarsal bones have been the subject of many studies, none of which has used stereological methods to estimate the volume. In the present stereological study, we estimated the volume of calcaneal bone of normal feet and dry bones. We used a combination of the Cavalieri principle and computer tomographic scans taken from eight males and nine dry calcanei to estimate the volumes of calcaneal bones. The mean volume of dry calcaneal bones was estimated, producing mean results using the point-counting method and Archimedes principle being 49.11+/-10.7 or 48.22+/-11.92 cm(3), respectively. A positive correlation was found between anthropometric measurements and the volume of calcaneal bones. The findings of the present study using the stereological methods could provide data for the evaluation of normal and pathological volumes of calcaneal bones.

Bone Histology of Two Cases with Osteomalacia Related to Low-dose Adefovir.

PubMed

Hiramatsu, Rikako; Ubara, Yoshifumi; Sawa, Naoki; Hasegawa, Eiko; Kawada, Masahiro; Imafuku, Aya; Sumida, Keiichi; Hoshino, Junichi; Takaichi, Kenmei

We performed a bone histomorphometric analysis in two patients demonstrating Fanconi syndrome with hypophosphatemia, adefovir-related bone disease and chronic hepatitis B infection. Both patients had osteomalacia, but showed two different histological patterns. The osteoid volume of the patient without risedronate increased with [(osteoid volume/ bone volume)×100=18.6%]. However, the osteoid volume of the patient receiving risedronate without vitamin D analogue showed a greater increase of 53.8%. In both patients bone pain and hypophosphatemia subsided soon after the discontinuation of adefovir and the administration of phosphate derivative. These findings show that bisphosphonate may worsen this disease when this drug is administered without a vitamin D analogue.

A soluble bone morphogenetic protein type IA receptor increases bone mass and bone strength

PubMed Central

Baud’huin, Marc; Solban, Nicolas; Cornwall-Brady, Milton; Sako, Dianne; Kawamoto, Yoshimi; Liharska, Katia; Lath, Darren; Bouxsein, Mary L.; Underwood, Kathryn W.; Ucran, Jeffrey; Kumar, Ravindra; Pobre, Eileen; Grinberg, Asya; Seehra, Jasbir; Canalis, Ernesto; Pearsall, R. Scott; Croucher, Peter I.

2012-01-01

Diseases such as osteoporosis are associated with reduced bone mass. Therapies to prevent bone loss exist, but there are few that stimulate bone formation and restore bone mass. Bone morphogenetic proteins (BMPs) are members of the TGFβ superfamily, which act as pleiotropic regulators of skeletal organogenesis and bone homeostasis. Ablation of the BMPR1A receptor in osteoblasts increases bone mass, suggesting that inhibition of BMPR1A signaling may have therapeutic benefit. The aim of this study was to determine the skeletal effects of systemic administration of a soluble BMPR1A fusion protein (mBMPR1A–mFc) in vivo. mBMPR1A–mFc was shown to bind BMP2/4 specifically and with high affinity and prevent downstream signaling. mBMPR1A–mFc treatment of immature and mature mice increased bone mineral density, cortical thickness, trabecular bone volume, thickness and number, and decreased trabecular separation. The increase in bone mass was due to an early increase in osteoblast number and bone formation rate, mediated by a suppression of Dickkopf-1 expression. This was followed by a decrease in osteoclast number and eroded surface, which was associated with a decrease in receptor activator of NF-κB ligand (RANKL) production, an increase in osteoprotegerin expression, and a decrease in serum tartrate-resistant acid phosphatase (TRAP5b) concentration. mBMPR1A treatment also increased bone mass and strength in mice with bone loss due to estrogen deficiency. In conclusion, mBMPR1A–mFc stimulates osteoblastic bone formation and decreases bone resorption, which leads to an increase in bone mass, and offers a promising unique alternative for the treatment of bone-related disorders. PMID:22761317

Hydrogel Delivery of Mesenchymal Stem Cell–Expressing Bone Morphogenetic Protein-2 Enhances Bone Defect Repair

PubMed Central

Hsiao, Hui-Yi; Yang, Shu-Rui; Brey, Eric M.; Chu, I-Ming

2016-01-01

Background: The application of bone tissue engineering for repairing bone defects has gradually shown some satisfactory progress. One of the concerns raising scientific attention is the poor supply of growth factors. A number of growth factor delivery approaches have been developed for promoting bone formation. However, there is no systematic comparison of those approaches on efficiency of neobone formation. In this study, the approaches using periosteum, direct supply of growth factors, or gene transfection of growth factors were evaluated to determine the osteogenic capacity on the repair of bone defect. Methods: In total, 42 male 21-week-old Sprague-Dawley rats weighing 250 to 400 g were used as the bone defect model to evaluate the bone repair efficiency. Various tissue engineered constructs of poly(ethylene glycol)-poly(l-lactic acid) (PEG-PLLA) copolymer hydrogel with periosteum, with external supply of bone morphogenetic protein-2 (BMP2), or with BMP2-transfected bone marrow–derived mesenchymal stem cells (BMMSCs) were filled in a 7-mm bone defect region. Animals were euthanized at 3 months, and the hydrogel constructs were harvested. The evaluation with histological staining and radiography analysis were performed for the volume of new bone formation. Results: The PEG-PLLA scaffold with BMMSCs promotes bone regeneration with the addition of periosteum. The group with BMP2-transfected BMMSCs demonstrated the largest volume of new bone among all the testing groups. Conclusions: Altogether, the results of this study provide the evidence that the combination of PEG-PLLA hydrogels with BMMSCs and sustained delivery of BMP2 resulted in the maximal bone regeneration. PMID:27622106

Permanence of diced cartilage, bone dust and diced cartilage/bone dust mixture in experimental design in twelve weeks.

PubMed

Islamoglu, Kemal; Dikici, Mustafa Bahadir; Ozgentas, Halil Ege

2006-09-01

Bone dust and diced cartilage are used for contour restoration because their minimal donor site morbidity. The purpose of this study is to investigate permanence of bone dust, diced cartilage and bone dust/diced cartilage mixture in rabbits over 12 weeks. New Zealand white rabbits were used for this study. There were three groups in the study: Group I: 1 mL bone dust. Group II: 1 mL diced cartilage. Group III: 0.5 mL bone dust + 0.5 mL diced cartilage mixture. They were placed into subcutaneous tissue of rabbits and removed 12 weeks later. The mean volumes of groups were 0.23 +/- 0.08 mL in group I, 0.60 +/- 0.12 mL in group II and 0.36 +/- 0.10 mL in group III. The differences between groups were found statistically significant. In conclusion, diced cartilage was found more reliable than bone dust aspect of preserving its volume for a long period in this study.

Three-dimensional visualization and characterization of bone structure using reconstructed in-vitro μCT images: A pilot study for bone microarchitecture analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Latief, Fourier Dzar Eljabbar, E-mail: fourier@fi.itb.ac.id; Dewi, Dyah Ekashanti Octorina; Shari, Mohd Aliff Bin Mohd

Micro Computed Tomography (μCT) has been largely used to perform micrometer scale imaging of specimens, bone biopsies and small animals for the study of porous or cavity-containing objects. One of its favored applications is for assessing structural properties of bone. In this research, we perform a pilot study to visualize and characterize bone structure of a chicken bone thigh, as well as to delineate its cortical and trabecular bone regions. We utilize an In-Vitro μCT scanner Skyscan 1173 to acquire a three dimensional image data of a chicken bone thigh. The thigh was scanned using X-ray voltage of 45 kVmore » and current of 150 μA. The reconstructed images have spatial resolution of 142.50 μm/pixel. Using image processing and analysis e.i segmentation by thresholding the gray values (which represent the pseudo density) and binarizing the images, we were able to visualize each part of the bone, i.e., the cortical and trabecular regions. Total volume of the bone is 4663.63 mm{sup 3}, and the surface area of the bone is 7913.42 mm{sup 2}. The volume of the cortical is approximately 1988.62 mm{sup 3} which is nearly 42.64% of the total bone volume. This pilot study has confirmed that the μCT is capable of quantifying 3D bone structural properties and defining its regions separately. For further development, these results can be improved for understanding the pathophysiology of bone abnormality, testing the efficacy of pharmaceutical intervention, or estimating bone biomechanical properties.« less

Lateral approach for maxillary sinus membrane elevation without bone materials in maxillary mucous retention cyst with immediate or delayed implant rehabilitation: case reports.

PubMed

Han, Ji-Deuk; Cho, Seong-Ho; Jang, Kuk-Won; Kim, Seong-Gwang; Kim, Jung-Han; Kim, Bok-Joo; Kim, Chul-Hun

2017-08-01

This case series study demonstrates the possibility of successful implant rehabilitation without bone augmentation in the atrophic posterior maxilla with cystic lesion in the sinus. Sinus lift without bone graft using the lateral approach was performed. In one patient, the cyst was aspirated and simultaneous implantation under local anesthesia was performed, whereas the other cyst was removed under general anesthesia, and the sinus membrane was elevated in a second process, followed by implantation. In both cases, tapered 11.5-mm-long implants were utilized. With all of the implants, good stability and appropriate bone height were achieved. The mean bone level gain was 5.73 mm; adequate bone augmentation around the implants was shown, the sinus floor was moved apically, and the cyst was no longer radiologically detected. Completion of all of the treatments required an average of 12.5 months. The present study showed that sufficient bone formation and stable implantation in a maxilla of insufficient bone volume are possible through sinus lift without bone materials. The results serve to demonstrate, moreover, that surgical treatment of mucous retention cyst can facilitate rehabilitation. These techniques can reduce the risk of complications related to bone grafts, save money, and successfully treat antral cyst.

Lateral approach for maxillary sinus membrane elevation without bone materials in maxillary mucous retention cyst with immediate or delayed implant rehabilitation: case reports

PubMed Central

2017-01-01

This case series study demonstrates the possibility of successful implant rehabilitation without bone augmentation in the atrophic posterior maxilla with cystic lesion in the sinus. Sinus lift without bone graft using the lateral approach was performed. In one patient, the cyst was aspirated and simultaneous implantation under local anesthesia was performed, whereas the other cyst was removed under general anesthesia, and the sinus membrane was elevated in a second process, followed by implantation. In both cases, tapered 11.5-mm-long implants were utilized. With all of the implants, good stability and appropriate bone height were achieved. The mean bone level gain was 5.73 mm; adequate bone augmentation around the implants was shown, the sinus floor was moved apically, and the cyst was no longer radiologically detected. Completion of all of the treatments required an average of 12.5 months. The present study showed that sufficient bone formation and stable implantation in a maxilla of insufficient bone volume are possible through sinus lift without bone materials. The results serve to demonstrate, moreover, that surgical treatment of mucous retention cyst can facilitate rehabilitation. These techniques can reduce the risk of complications related to bone grafts, save money, and successfully treat antral cyst. PMID:28875144

Symmetry analysis of talus bone

PubMed Central

Islam, K.; Dobbe, A.; Komeili, A.; Duke, K.; El-Rich, M.; Dhillon, S.; Adeeb, S.; Jomha, N. M.

2014-01-01

Objective The main object of this study was to use a geometric morphometric approach to quantify the left-right symmetry of talus bones. Methods Analysis was carried out using CT scan images of 11 pairs of intact tali. Two important geometric parameters, volume and surface area, were quantified for left and right talus bones. The geometric shape variations between the right and left talus bones were also measured using deviation analysis. Furthermore, location of asymmetry in the geometric shapes were identified. Results Numerical results showed that talus bones are bilaterally symmetrical in nature, and the difference between the surface area of the left and right talus bones was less than 7.5%. Similarly, the difference in the volume of both bones was less than 7.5%. Results of the three-dimensional (3D) deviation analyses demonstrated the mean deviation between left and right talus bones were in the range of -0.74 mm to 0.62 mm. It was observed that in eight of 11 subjects, the deviation in symmetry occurred in regions that are clinically less important during talus surgery. Conclusions We conclude that left and right talus bones of intact human ankle joints show a strong degree of symmetry. The results of this study may have significance with respect to talus surgery, and in investigating traumatic talus injury where the geometric shape of the contralateral talus can be used as control. Cite this article: Bone Joint Res 2014;3:139–45. PMID:24802391

Bone health in persons with haemophilia.

PubMed

Kempton, C L; Antoniucci, D M; Rodriguez-Merchan, E C

2015-09-01

As the population of patients with haemophilia (PWH) ages, healthcare providers are required to direct greater attention to age-related co-morbidities. Low bone mineral density (BMD) is one such co-morbidity where the incidence not only increases with age, but also occurs with greater frequency in PWH. To review risk factors for low BMD, and strategies to promote bone health and identify patients who would benefit from screening for osteoporosis and subsequent treatment. A narrative review of the literature was performed in MEDLINE with keywords haemophilia, bone density, osteoporosis and fracture. Reference lists of retrieved articles were also reviewed. Low BMD occurs more commonly in PWH than the general population and is most likely the result of a combination of risk factors.  Steps to promote bone health include preventing haemarthrosis, encouraging regular exercise, adequate vitamin D and calcium intake, and avoiding tobacco and excessive alcohol intake. Adults 50 years of age and older with haemophilia and those younger than 50 years with a fragility fracture or increased fracture risk based on FRAX (The Fracture Risk Assessment Tool), regardless of haemophilia severity, should be screened for low BMD using dual x-ray absorptiometry (DXA). Once osteoporosis is diagnosed based on DXA, fracture risk should guide treatment. Currently, treatment is similar to those without haemophilia and most commonly includes bisphosphonates. Haemophilia care providers should promote adequate bone formation during childhood and reduce bone loss during adulthood as well as identify patients with low BMD that would benefit from therapy. © 2015 John Wiley & Sons Ltd.

Halofuginone Attenuates Osteoarthritis by Rescuing Bone Remodeling in Subchondral Bone Through Oral Gavage

PubMed Central

Mu, Wenbo; Xu, Boyong; Ma, Hairong; Li, Jiao; Ji, Baochao; Zhang, Zhendong; Amat, Abdusami; Cao, Li

2018-01-01

Osteoarthritis (OA) is a common debilitating joint disorder worldwide without effective medical therapy. Articular cartilage and subchondral bone act in concert as a functional unit with the onset of OA. Halofuginone is an analog of the alkaloid febrifugine extracted from the plant Dichroa febrifuga, which has been demonstrated to exert inhibition of SMAD 2/3 phosphorylation downstream of the TGF-β signaling pathway and osteoclastogenesis. To investigate whether halofuginone (HF) alleviates OA after administration by oral gavage, 3-month-old male mice were allocated to the Sham group, vehicle-treated anterior cruciate ligament transection (ACLT) group, and HF-treated ACLT group. The immunostaining analysis indicated that HF reduced the number of matrix metalloproteinase 13 (MMP-13) and collagen X (Col X) positive cells in the articular cartilage. Moreover, HF lowered histologic OA score and prevented articular cartilage degeneration. The micro-computed tomography (μCT) scan showed that HF maintained the subchondral bone microarchitecture, demonstrated by the restoration of bone volume fraction (BV/TV), subchondral bone plate thickness (SBP.Th.), and trabecular pattern factor (Tb.Pf) to a level comparable to that of the Sham group. Immunostaining for CD31 and μCT based angiography showed that the number and volume of vessels in subchondral bone was restored by HF. HF administered by oral gavage recoupled bone remodeling and inhibited aberrant angiogenesis in the subchondral bone, further slowed the progression of OA. Therefore, HF administered by oral gavage could be a potential therapy for OA. PMID:29636687

A Biphasic Calcium Sulphate/Hydroxyapatite Carrier Containing Bone Morphogenic Protein-2 and Zoledronic Acid Generates Bone

PubMed Central

Raina, Deepak Bushan; Isaksson, Hanna; Hettwer, Werner; Kumar, Ashok; Lidgren, Lars; Tägil, Magnus

2016-01-01

In orthopedic surgery, large amount of diseased or injured bone routinely needs to be replaced. Autografts are mainly used but their availability is limited. Commercially available bone substitutes allow bone ingrowth but lack the capacity to induce bone formation. Thus, off-the-shelf osteoinductive bone substitutes that can replace bone grafts are required. We tested the carrier properties of a biphasic, calcium sulphate and hydroxyapatite ceramic material, containing a combination of recombinant human bone morphogenic protein-2 (rhBMP-2) to induce bone, and zoledronic acid (ZA) to delay early resorption. In-vitro, the biphasic material released 90% of rhBMP-2 and 10% of ZA in the first week. No major changes were found in the surface structure using scanning electron microscopy (SEM) or in the mechanical properties after adding rhBMP-2 or ZA. In-vivo bone formation was studied in an abdominal muscle pouch model in rats (n = 6/group). The mineralized volume was significantly higher when the biphasic material was combined with both rhBMP-2 and ZA (21.4 ± 5.5 mm3) as compared to rhBMP-2 alone (10.9 ± 2.1 mm3) when analyzed using micro computed tomography (μ-CT) (p < 0.01). In the clinical setting, the biphasic material combined with both rhBMP-2 and ZA can potentially regenerate large volumes of bone. PMID:27189411

Bone Histology of Two Cases with Osteomalacia Related to Low-dose Adefovir

PubMed Central

Hiramatsu, Rikako; Ubara, Yoshifumi; Sawa, Naoki; Hasegawa, Eiko; Kawada, Masahiro; Imafuku, Aya; Sumida, Keiichi; Hoshino, Junichi; Takaichi, Kenmei

2016-01-01

We performed a bone histomorphometric analysis in two patients demonstrating Fanconi syndrome with hypophosphatemia, adefovir-related bone disease and chronic hepatitis B infection. Both patients had osteomalacia, but showed two different histological patterns. The osteoid volume of the patient without risedronate increased with [(osteoid volume/ bone volume)×100=18.6%]. However, the osteoid volume of the patient receiving risedronate without vitamin D analogue showed a greater increase of 53.8%. In both patients bone pain and hypophosphatemia subsided soon after the discontinuation of adefovir and the administration of phosphate derivative. These findings show that bisphosphonate may worsen this disease when this drug is administered without a vitamin D analogue. PMID:27746441

Motion of bones and volume changes in the neurocranium after craniectomy in Crouzon's disease. A roentgen stereometric study.

PubMed

Rune, B; Selvik, G; Kreiborg, S; Sarnäs, K V; Kågström, E

1979-04-01

Craniectomy was performed on a boy with Crouzon's disease at 22 months of age. Metallic implants (tantalum balls, 0.5 mm in diameter) were inserted in the calvaria during surgery, and the child was examined postoperatively by roentgen stereometry at intervals of about 100 days (total observation time, 309 days). The thyroid radiation dose was 250 muGy for one examination. The effect of craniectomy was recorded with a high degree of accuracy in terms of motion of bones and volume changes in the calvaria. Expansion occurred almost entirely through motion of free bone flaps in the frontal region, while a linear craniectomy in the region of the sagittal suture caused small changes. The rate of expansion decreased rapidly and stabilization was recorded about 250 days after surgery.

Patient adviser banking on strong bones for life: do you need calcium supplements?

PubMed

Harmon, Kimberly G

2002-03-01

Calcium is important for building strong teeth and bones and for preventing osteoporosis. It is especially important that adolescents and young adults get adequate amounts of calcium. In women, bone density can increase until around age 30. After that, bone mass is maintained or lost at a slow rate until menopause, when the rate of bone loss increases.

Yeast-incorporated gallium attenuates glucocorticoid-induced bone loss in rats by inhibition of bone resorption.

PubMed

Ren, Zhaozhou; Yang, Liqing; Xue, Feng; Meng, Qingjie; Wang, Kejia; Wu, Xian; Ji, Chao; Jiang, Teng; Liu, Da; Zhou, Long; Zhang, Jing; Fu, Qin

2013-06-01

Glucocorticoids (GC) are potent anti-inflammatory agents and widely used for the treatment of many immune-mediated and inflammatory diseases, whereas GC-induced osteoporosis (GIOP) is the most common cause of secondary osteoporosis and significantly increases the patients' morbidity and mortality. GIOP is characterized as diminished osteogenesis and accelerated bone resorption. Yeast-incorporated gallium (YG) as an organic compound not only reduces elements-associated toxicity, but also maintains its therapeutic effect on improving bone loss or promoting fracture healing in ovariectomized female rats. The aim of this study was to examine whether YG could prevent GC-induced bone loss. Five-month-old male Sprague-Dawley rats were randomly divided into three groups (n = 6): two groups were administered dexamethasone (0.1 mg/kg/day) or vehicle (PBS) subcutaneously for 5 weeks; one other group was received dexamethasone subcutaneously and YG (120 μg/kg/day) orally. Trabecular bone microarchitectural parameters, bone mineral density (BMD), bone strength, body weight, and serum biochemical markers of bone resorption and formation were examined. Compared to the GC alone group, treatment with YG not only prevented microarchitectural deterioration of trabecular bone volume relative to tissue volume, trabecular number, and trabecular separation, but also significantly improved BMD, mechanical strength, and body weight in GC-treated rats. Moreover, YG decreased tartrate-resistant acid phosphatase 5b level but failed to change alkaline phosphatase level in GC-treated rats. This is the first study to show that YG prominently attenuates bone loss and microarchitectural deterioration and inhibits the increased bone resorption in GIOP. It implies that YG might be an alternative therapy for prevention of GC-induced bone loss in humans.

Impact of obesity on bone metabolism.

PubMed

López-Gómez, Juan J; Pérez Castrillón, José L; de Luis Román, Daniel A

2016-12-01

High weight is a protective factor against osteoporosis and risk of fracture. In obesity, however, where overweight is associated to excess fat, this relationship does not appear to be so clear, excess weight has sometimes been associated to decreased bone mass. Obesity interferes with bone metabolism through mechanical, hormonal, and inflammatory factors. These factors are closely related to weight, body composition, and dietary patterns of these patients. The net beneficial or harmful effect on bone mass or risk of fracture of the different components of this condition is not well known. We need to recognize patients at a greater risk of bone disease related to obesity to start an adequate intervention. Copyright © 2016. Publicado por Elsevier España, S.L.U.

Automated trabecular bone histomorphometry

NASA Technical Reports Server (NTRS)

Polig, E.; Jee, W. S. S.

1985-01-01

The toxicity of alpha-emitting bone-seeking radionuclides and the relationship between bone tumor incidence and the local dosimetry of radionuclides in bone are investigated. The microdistributions of alpha-emitting radionuclides in the trabecular bone from the proximal humerus, distal humerus, proximal ulna, proximal femur, and distal femur of six young adult beagles injected with Am-241 (three with 2.8 micro-Ci/kg and three with 0.9 micro-Ci/kg) are estimated using a computer-controlled microscope photometer system; the components of the University of Utah Optical Track Scanner are described. The morphometric parameters for the beagles are calculated and analyzed. It is observed that the beagles injected with 0.9 micro-Ci of Am-241/kg showed an increase in the percentage of bone and trabecular bone thickness, and a reduction in the width of the bone marrow space and surface/volume ratio. The data reveal that radiation damage causes abnormal bone structure.

Cortical bone thickening in Type A posterior atlas arch defects: experimental report.

PubMed

Sanchis-Gimeno, Juan A; Llido, Susanna; Guede, David; Martinez-Soriano, Francisco; Ramon Caeiro, Jose; Blanco-Perez, Esther

2017-03-01

To date, no information about the cortical bone microstructural properties in atlas vertebrae with posterior arch defects has been reported. To test if there is an increased cortical bone thickening in atlases with Type A posterior atlas arch defects in an experimental model. Micro-computed tomography (CT) study on cadaveric atlas vertebrae. We analyzed the cortical bone thickness, the cortical volume, and the medullary volume (SkyScan 1172 Bruker micro-CT NV, Kontich, Belgium) in cadaveric dry vertebrae with a Type A atlas arch defect and normal control vertebrae. The micro-CT study revealed significant differences in cortical bone thickness (p=.005), cortical volume (p=.003), and medullary volume (p=.009) values between the normal and the Type A vertebrae. Type A congenital atlas arch defects present a cortical bone thickening that may play a protective role against atlas fractures. Copyright © 2016 Elsevier Inc. All rights reserved.

Assessment of alveolar bone marrow fat content using 15 T MRI.

PubMed

Cortes, Arthur Rodriguez Gonzalez; Cohen, Ouri; Zhao, Ming; Aoki, Eduardo Massaharu; Ribeiro, Rodrigo Alves; Abu Nada, Lina; Costa, Claudio; Arita, Emiko Saito; Tamimi, Faleh; Ackerman, Jerome L

2018-03-01

Bone marrow fat is inversely correlated with bone mineral density. The aim of this study is to present a method to quantify alveolar bone marrow fat content using a 15 T magnetic resonance imaging (MRI) scanner. A 15 T MRI scanner with a 13-mm inner diameter loop-gap radiofrequency coil was used to scan seven 3-mm diameter alveolar bone biopsy specimens. A 3-D gradient-echo relaxation time (T1)-weighted pulse sequence was chosen to obtain images. All images were obtained with a voxel size (58 µm 3 ) sufficient to resolve trabecular spaces. Automated volume of the bone marrow fat content and derived bone volume fraction (BV/TV) were calculated. Results were compared with actual BV/TV obtained from micro-computed tomography (CT) scans. Mean fat tissue volume was 20.1 ± 11%. There was a significantly strong inverse correlation between fat tissue volume and BV/TV (r = -0.68; P = .045). Furthermore, there was a strong agreement between BV/TV derived from MRI and obtained with micro-CT (interclass correlation coefficient = 0.92; P = .001). Bone marrow fat of small alveolar bone biopsy specimens can be quantified with sufficient spatial resolution using an ultra-high-field MRI scanner and a T1-weighted pulse sequence. Copyright © 2017 Elsevier Inc. All rights reserved.

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

PubMed

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 < 0.0001) and AP (r(2) = 0.54, p < 0.0001). The determination of SI strength was improved to r(2) = 0.87 with the addition of mean rod length and relative plate bone volume fraction. The determination of AP strength was improved to r(2) = 0.85 with the addition of mean rod volume and relative rod bone volume fraction. Microarchitectural measures of individual trabeculae that contribute to bone strength have been identified. In addition to the contribution of BV/TV, trabecular rod morphology increased the determination of AP strength by 57%, whereas measures of trabecular plate and rod morphology increased determination of SI strength by 13%. Decomposing vertebral body bone architecture into its constituent

Computerized tomography-assisted calculation of sinus augmentation volume.

PubMed

Krennmair, Gerald; Krainhöfner, Martin; Maier, Harald; Weinländer, Michael; Piehslinger, Eva

2006-01-01

This study was intended to calculate the augmentation volume for a sinus lift procedure based on cross-sectional computerized tomography (CT) scans for 2 different augmentation heights. Based on area calculations of cross-sectional CT scans, the volume of additional bone needed was calculated for 44 sinus lift procedures. The amount of bone volume needed to raise the sinus floor to heights of both 12 and 17 mm was calculated. To achieve a sinus floor height of 12 mm, it was necessary to increase the height by a mean of 7.2+/-2.1 mm (range, 3.0 to 10.5 mm), depending on the residual ridge height; to achieve a height of 17 mm, a mean of 12.4+/-2.0 mm (range, 8.5 to 15.5 mm) was required (P < .01). The calculated augmentation volume for an augmentation height of 12 mm was 1.7+/-.9 cm3; for an augmentation height of 17 mm, the volume required was 3.6+/-1.5 cm3. Increasing the height of the sinus lift by 5 mm, ie, from 12 mm to 17 mm augmentation height, increased the augmentation volume by 100%. A significant correlation was found between augmentation height and the calculated sinus lift augmentation volume (r = 0. 78, P < .01). Detailed preoperative knowledge of sinus lift augmentation volume is helpful as a predictive value in deciding on a donor site for harvesting autogenous bone and on the ratio of bone to bone substitute to use. Calculation of the augmentation size can help determine the surgical approach and thus perioperative treatment and the costs of the surgery for both patients and clinicians.

The iodized salt programme in Bangalore, India provides adequate iodine intakes in pregnant women and more-than-adequate iodine intakes in their children.

PubMed

Jaiswal, Nidhi; Melse-Boonstra, Alida; Sharma, Surjeet Kaur; Srinivasan, Krishnamachari; Zimmermann, Michael B

2015-02-01

To compare the iodine status of pregnant women and their children who were sharing all meals in Bangalore, India. A cross-sectional study evaluating demographic characteristics, household salt iodine concentration and salt usage patterns, urinary iodine concentrations (UIC) in women and children, and maternal thyroid volume (ultrasound). Antenatal clinic of an urban tertiary-care hospital, which serves a low-income population. Healthy pregnant women in all trimesters, aged 18-35 years, who had healthy children aged 3-15 years. Median (range) iodine concentrations of household powdered and crystal salt were 55·9 (17·2-65·9) ppm and 18·9 (2·2-68·2) ppm, respectively. The contribution of iodine-containing supplements and multi-micronutrient powders to iodine intake in the families was negligible. Adequately iodized salt, together with small amounts of iodine in local foods, were providing adequate iodine during pregnancy: (i) the overall median (range) UIC in women was 172 (5-1024) µg/l; (ii) the median UIC was >150 µg/l in all trimesters; and (iii) thyroid size was not significantly different across trimesters. At the same time, the median (range) UIC in children was 220 (10-782) µg/l, indicating more-than-adequate iodine intake at this age. Median UIC was significantly higher in children than in their mothers (P=0·008). In this selected urban population of southern India, the iodized salt programme provides adequate iodine to women throughout pregnancy, at the expense of higher iodine intake in their children. Thus we suggest that the current cut-off for median UIC in children indicating more-than-adequate intake, recommended by the WHO/UNICEF/International Council for the Control of Iodine Deficiency Disorders may, need to be reconsidered.

Extending Rest between Unloading Cycles Does Not Enhance Bone's Long-Term Recovery.

PubMed

Manske, Sarah L; Vijayaraghavan, Surabhi; Tuthill, Alyssa; Brutus, Olivier; Yang, Jie; Gupta, Shikha; Judex, Stefan

2015-10-01

Multiple exposures to unloading are overall more deleterious to the skeleton than is single exposure, although the rate of bone loss may diminish during multiple exposures. Here, we determined whether extending the reambulation (RA) period from 3 wk to 9 wk will mitigate bone loss during three distinct 3-wk hindlimb unloading (HLU) periods and enhance long-term recovery in skeletally mature, genetically heterogeneous mice. Female adult mice (4 months old) were subjected to three cycles of 3-wk unloading with 3-wk or 9-wk RA periods in between. Mice were terminated 46 wk after initiation of the study. Outcome measures for the distal femur were determined from multiple in vivo micro-computed tomography scans and finite-element modeling. Tripling RA duration enhanced trabecular bone recovery in between HLU periods but also increased the rate of loss of bone volume fraction (bone volume/tissue volume) and metaphyseal stiffness during subsequent HLU periods. With shorter RA periods, the magnitude of bone loss decreased by the second HLU period, whereas this decrease was delayed with longer RA periods. RA duration did not affect long-term recovery 46 wk after the start of the experimental protocol, as both HLU groups had similar levels of bone volume/tissue volume, cortical area, and stiffness. Individual cage activity levels were unrelated to the magnitude of bone loss during HLU or bone recovery during RA. These data suggest that extending recovery duration between periods of unloading may provide temporary benefits but is an ineffective long-term strategy for combating the devastation of trabecular morphology and mechanics, as temporarily enhanced recovery is largely cancelled out by greater susceptibility to unloading. They also emphasize that cortical bone is more amenable to long-term recovery than is trabecular bone.

Guided bone regeneration using individualized ceramic sheets.

PubMed

Malmström, J; Anderud, J; Abrahamsson, P; Wälivaara, D-Å; Isaksson, S G; Adolfsson, E

2016-10-01

Guided bone regeneration (GBR) describes the use of membranes to regenerate bony defects. A membrane for GBR needs to be biocompatible, cell-occlusive, non-toxic, and mouldable, and possess space-maintaining properties including stability. The purpose of this pilot study was to describe a new method of GBR using individualized ceramic sheets to perfect bone regeneration prior to implant placement; bone regeneration was assessed using traditional histology and three-dimensional (3D) volumetric changes in the bone and soft tissue. Three patients were included. After full-thickness flap reflection, the individualized ceramic sheets were fixed. The sites were left to heal for 7 months. All patients were evaluated preoperatively and at 7 months postoperative using cone beam computed tomography and 3D optical equipment. Samples of the regenerated bone and soft tissue were collected and analyzed. The bone regenerated in the entire interior volume of all sheets. Bone biopsies revealed newly formed trabecular bone with a lamellar structure. Soft tissue biopsies showed connective tissue with no signs of an inflammatory response. This was considered to be newly formed periosteum. Thus ceramic individualized sheets can be used to regenerate large volumes of bone in both vertical and horizontal directions independent of the bone defect and with good biological acceptance of the material. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Cosmos 1129 - Spaceflight and bone changes

NASA Technical Reports Server (NTRS)

Wronski, T. J.; Morey-Holton, E.; Jee, W. S. S.

1980-01-01

Male Wistar rats were placed in orbit for an 18.5 day period aboard the Soviet Cosmos 1129 biological satellite. The skeletal changes which occurred during spaceflight were determined to be a reduced rate of periosteal bone formation in the tibial and humeral diaphyses, and a decreased trabecular bone volume and an increased fat content of the bone marrow in the proximal tibial metaphysis.

Mathematical modelling of bone adaptation of the metacarpal subchondral bone in racehorses.

PubMed

Hitchens, Peta L; Pivonka, Peter; Malekipour, Fatemeh; Whitton, R Chris

2018-06-01

In Thoroughbred racehorses, fractures of the distal limb are commonly catastrophic. Most of these fractures occur due to the accumulation of fatigue damage from repetitive loading, as evidenced by microdamage at the predilection sites for fracture. Adaptation of the bone in response to training loads is important for fatigue resistance. In order to better understand the mechanism of subchondral bone adaptation to its loading environment, we utilised a square root function defining the relationship between bone volume fraction [Formula: see text] and specific surface [Formula: see text] of the subchondral bone of the lateral condyles of the third metacarpal bone (MCIII) of the racehorse, and using this equation, developed a mathematical model of subchondral bone that adapts to loading conditions observed in vivo. The model is expressed as an ordinary differential equation incorporating a formation rate that is dependent on strain energy density. The loading conditions applied to a selected subchondral region, i.e. volume of interest, were estimated based on joint contact forces sustained by racehorses in training. For each of the initial conditions of [Formula: see text] we found no difference between subsequent homoeostatic [Formula: see text] at any given loading condition, but the time to reach equilibrium differed by initial [Formula: see text] and loading condition. We found that the observed values for [Formula: see text] from the mathematical model output were a good approximation to the existing data for racehorses in training or at rest. This model provides the basis for understanding the effect of changes to training strategies that may reduce the risk of racehorse injury.

Effects of Condensation on Peri-implant Bone Density and Remodeling

PubMed Central

Wang, L.; Wu, Y.; Perez, K.C.; Hyman, S.; Brunski, J.B.; Tulu, U.; Bao, C.; Salmon, B.; Helms, J.A.

2017-01-01

Bone condensation is thought to densify interfacial bone and thus improve implant primary stability, but scant data substantiate either claim. We developed a murine oral implant model to test these hypotheses. Osteotomies were created in healed maxillary extraction sites 1) by drilling or 2) by drilling followed by stepwise condensation with tapered osteotomes. Condensation increased interfacial bone density, as measured by a significant change in bone volume/total volume and trabecular spacing, but it simultaneously damaged the bone. On postimplant day 1, the condensed bone interface exhibited microfractures and osteoclast activity. Finite element modeling, mechanical testing, and immunohistochemical analyses at multiple time points throughout the osseointegration period demonstrated that condensation caused very high interfacial strains, marginal bone resorption, and no improvement in implant stability. Collectively, these multiscale analyses demonstrate that condensation does not positively contribute to implant stability. PMID:28048963

Effects of Condensation on Peri-implant Bone Density and Remodeling.

PubMed

Wang, L; Wu, Y; Perez, K C; Hyman, S; Brunski, J B; Tulu, U; Bao, C; Salmon, B; Helms, J A

2017-04-01

Bone condensation is thought to densify interfacial bone and thus improve implant primary stability, but scant data substantiate either claim. We developed a murine oral implant model to test these hypotheses. Osteotomies were created in healed maxillary extraction sites 1) by drilling or 2) by drilling followed by stepwise condensation with tapered osteotomes. Condensation increased interfacial bone density, as measured by a significant change in bone volume/total volume and trabecular spacing, but it simultaneously damaged the bone. On postimplant day 1, the condensed bone interface exhibited microfractures and osteoclast activity. Finite element modeling, mechanical testing, and immunohistochemical analyses at multiple time points throughout the osseointegration period demonstrated that condensation caused very high interfacial strains, marginal bone resorption, and no improvement in implant stability. Collectively, these multiscale analyses demonstrate that condensation does not positively contribute to implant stability.

In vivo analysis of biocompatibility and vascularization of the synthetic bone grafting substitute NanoBone.

PubMed

Abshagen, K; Schrodi, I; Gerber, T; Vollmar, B

2009-11-01

One of the major challenges in the application of bone substitutes is adequate vascularization and biocompatibility of the implant. Thus, the temporal course of neovascularization and the microvascular inflammatory response of implants of NanoBone (fully synthetic nanocrystalline bone grafting material) were studied in vivo by using the mouse dorsal skinfold chamber model. Angiogenesis, microhemodynamics, and leukocyte-endothelial cell interaction were analyzed repetitively after implantation in the center and in the border zone of the implant up to 15 days. Both NanoBone granules and plates exhibited high biocompatibility comparable to that of cancellous bone, as indicated by a lack of venular leukocyte activation after implantation. In both synthetic NanoBone groups, signs of angiogenesis could be observed even at day 5 after implantation, whereas granules showed higher functional vessel density compared with NanoBone plates. The angiogenic response of the cancellous bone was markedly accelerated in the center of the implant tissue. Histologically, implant tissue showed an ingrowth of vascularized fibrous tissue into the material combined with an increased number of foreign-body giant cells. In conclusion, NanoBone, particularly in granular form, showed high biocompatibility and high angiogenic response, thus improving the healing of bone defects. Our results underline that, beside the composition and nanostructure, the macrostructure is also of importance for the incorporation of the biomaterial by the host tissue. (c) 2008 Wiley Periodicals, Inc.

Functional adaptation to mechanical loading in both cortical and cancellous bone is controlled locally and is confined to the loaded bones.

PubMed

Sugiyama, Toshihiro; Price, Joanna S; Lanyon, Lance E

2010-02-01

In order to validate whether bones' functional adaptation to mechanical loading is a local phenomenon, we randomly assigned 21 female C57BL/6 mice at 19 weeks of age to one of three equal numbered groups. All groups were treated with isoflurane anesthesia three times a week for 2 weeks (approximately 7 min/day). During each anaesthetic period, the right tibiae/fibulae in the DYNAMIC+STATIC group were subjected to a peak dynamic load of 11.5 N (40 cycles with 10-s intervals between cycles) superimposed upon a static "pre-load" of 2.0 N. This total load of 13.5 N engendered peak longitudinal strains of approximately 1400 microstrain on the medial surface of the tibia at a middle/proximal site. The right tibiae/fibulae in the STATIC group received the static "pre-load" alone while the NOLOAD group received no artificial loading. After 2 weeks, the animals were sacrificed and both tibiae, fibulae, femora, ulnae and radii analyzed by three-dimensional high-resolution (5 mum) micro-computed tomography (microCT). In the DYNAMIC+STATIC group, the proximal trabecular percent bone volume and cortical bone volume at the proximal and middle levels of the right tibiae as well as the cortical bone volume at the middle level of the right fibulae were markedly greater than the left. In contrast, the left bones in the DYNAMIC+STATIC group showed no differences compared to the left or right bones in the NOLOAD or STATIC group. These microCT data were confirmed by two-dimensional examination of fluorochrome labels in bone sections which showed the predominantly woven nature of the new bone formed in the loaded bones. We conclude that the adaptive response in both cortical and trabecular regions of bones subjected to short periods of dynamic loading, even when this response is sufficiently vigorous to stimulate woven bone formation, is confined to the loaded bones and does not involve changes in other bones that are adjacent, contra-lateral or remote to them. (c) 2009 Elsevier Inc

Bone morphology changes around two types of bone-level implants installed in fresh extraction sockets--a histomorphometric study in Beagle dogs.

PubMed

Alharbi, Hend M; Babay, Nadir; Alzoman, Hamad; Basudan, Sumaya; Anil, Sukumaran; Jansen, John A

2015-09-01

Minimizing crestal bone loss following immediate implant placement is considered the most challenging aspect in implant therapy. Implant surface topography and chemical modifications have been shown to influence the success of Osseointegration. The Straumann Bone Level implant, featuring SLActive surface, has been introduced with the aim of enhancing bone apposition. Similarly, the OsseoSpeed implants from Astra Tech claim to have an enhanced osseointegration. Because of the specific features in the implant design, both companies claim that crestal resorption is minimal with these implants. To evaluate the osseointegration and crestal bone level following immediate placement of Straumann Bone Level implant and OsseoSpeed implants in fresh extraction sockets in Beagle dogs. The distal roots of the second, third and fourth premolars were extracted in both sides of the mandible. The distal roots were removed using a dental elevator. A total of 60 fixtures were installed in 10 Beagle dogs. Two types of implants were used: Straumann Bone-Level implants, which were 8 × 3.3 mm in size, and Astra Tech OsseoSpeed 3.5 S MicroThread implants, which were 8 × 3.5 mm in size. The histomorphometrical evaluation was performed at the end of 4- and 12-week healing. The implant-bone contact and bone volume percentage were assessed. The bone-to-implant contact (BIC) and the bone volume did not show any significant changes for both types of implants. The OsseoSpeed™ implants showed 67.4% and 65.3% BIC, respectively, at 4 and 12 weeks compared with 71.7 and 73.1 for the Straumann Bone-Level implants. The bone volume around both types of implants did not differ significantly at both time periods. The crestal bone resorption was observed for both types of implants. The first BIC at buccal side and lingual side of the implants also did not differ significantly for both implant systems. This study showed that Straumann Bone Level and OsseoSpeed implants induced similar bone response

Building a bone μCT images atlas for micro-architecture recognition

NASA Astrophysics Data System (ADS)

Freuchet, E.; Recur, B.; Guédon, Jp.; Kingston, A.; Autrusseau, F.; Amouriq, Y.

2015-03-01

Trabecular bone and its micro-architecture are of prime importance for health. Changes of bone micro-architecture are linked to different pathological situations like osteoporosis and begin now to be understood. In a previous paper, we started to investigate the relationships between bone and vessels and we also proposed to build a Bone Atlas. This study describes how to proceed for the elaboration and use of such an atlas. Here, we restricted the Atlas to legs (tibia, femur) of rats in order to work with well known geometry of the bone micro-architecture. From only 6 acquired bone, 132 trabecular bone volumes were generated using simple mathematical morphology tools. The variety and veracity of the created micro-architecture volumes is presented in this paper. Medical application and final goal would be to determinate bone micro-architecture with some angulated radiographs (3 or 4) and to easily diagnose the bone status (healthy, pathological or healing bone...).

Porotic paradox: distribution of cortical bone pore sizes at nano- and micro-levels in healthy vs. fragile human bone.

PubMed

Milovanovic, Petar; Vukovic, Zorica; Antonijevic, Djordje; Djonic, Danijela; Zivkovic, Vladimir; Nikolic, Slobodan; Djuric, Marija

2017-05-01

Bone is a remarkable biological nanocomposite material showing peculiar hierarchical organization from smaller (nano, micro) to larger (macro) length scales. Increased material porosity is considered as the main feature of fragile bone at larger length-scales. However, there is a shortage of quantitative information on bone porosity at smaller length-scales, as well as on the distribution of pore sizes in healthy vs. fragile bone. Therefore, here we investigated how healthy and fragile bones differ in pore volume and pore size distribution patterns, considering a wide range of mostly neglected pore sizes from nano to micron-length scales (7.5 to 15000 nm). Cortical bone specimens from four young healthy women (age: 35 ± 6 years) and five women with bone fracture (age: 82 ± 5 years) were analyzed by mercury porosimetry. Our findings showed that, surprisingly, fragile bone demonstrated lower pore volume at the measured scales. Furtnermore, pore size distribution showed differential patterns between healthy and fragile bones, where healthy bone showed especially high proportion of pores between 200 and 15000 nm. Therefore, although fragile bones are known for increased porosity at macroscopic level and level of tens or hundreds of microns as firmly established in the literature, our study with a unique assessment range of nano-to micron-sized pores reveal that osteoporosis does not imply increased porosity at all length scales. Our thorough assessment of bone porosity reveals a specific distribution of porosities at smaller length-scales and contributes to proper understanding of bone structure which is important for designing new biomimetic bone substitute materials.

Recent progress in injectable bone repair materials research

NASA Astrophysics Data System (ADS)

Chen, Zonggang; Zhang, Xiuli; Kang, Lingzhi; Xu, Fei; Wang, Zhaoling; Cui, Fu-Zhai; Guo, Zhongwu

2015-12-01

Minimally invasive injectable self-setting materials are useful for bone repairs and for bone tissue regeneration in situ. Due to the potential advantages of these materials, such as causing minimal tissue injury, nearly no influence on blood supply, easy operation and negligible postoperative pain, they have shown great promises and successes in clinical applications. It has been proposed that an ideal injectable bone repair material should have features similar to that of natural bones, in terms of both the microstructure and the composition, so that it not only provides adequate stimulus to facilitate cell adhesion, proliferation and differentiation but also offers a satisfactory biological environment for new bone to grow at the implantation site. This article reviews the properties and applications of injectable bone repair materials, including those that are based on natural and synthetic polymers, calcium phosphate, calcium phosphate/polymer composites and calcium sulfate, to orthopedics and bone tissue repairs, as well as the progress made in biomimetic fabrication of injectable bone repair materials.

Heritability of Lumbar Trabecular Bone Mechanical Properties in Baboons

PubMed Central

Havill, L.M.; Allen, M.R.; Bredbenner, T.L.; Burr, D.B.; Nicolella, D.P.; Turner, C.H.; Warren, D.M.; Mahaney, M.C.

2010-01-01

Genetic effects on mechanical properties have been demonstrated in rodents, but not confirmed in primates. Our aim was to quantify the proportion of variation in vertebral trabecular bone mechanical properties that is due to the effects of genes. L3 vertebrae were collected from 110 females and 46 male baboons (6–32 years old) from a single extended pedigree. Cranio-caudally oriented trabecular bone cores were scanned with microCT then tested in monotonic compression to determine apparent ultimate stress, modulus, and toughness. Age and sex effects and heritability (h2) were assessed using maximum likelihood-based variance components methods. Additive effects of genes on residual trait variance were significant for ultimate stress (h2=0.58), toughness (h2=0.64), and BV/TV (h2=0.55). When BV/TV was accounted for, the residual variance in ultimate stress accounted for by the additive effects of genes was no longer significant. Toughness, however, showed evidence of a non-BV/TV-related genetic effect. Overall, maximum stress and modulus show strong genetic effects that are nearly entirely due to bone volume. Toughness shows strong genetic effects related to bone volume and shows additional genetic effects (accounting for 10% of the total trait variance) that are independent of bone volume. These results support continued use of bone volume as a focal trait to identify genes related to skeletal fragility, but also show that other focal traits related to toughness and variation in the organic component of bone matrix will enhance our ability to find additional genes that are particularly relevant to fatigue-related fractures. PMID:19900599

An approximate model for cancellous bone screw fixation.

PubMed

Brown, C J; Sinclair, R A; Day, A; Hess, B; Procter, P

2013-04-01

This paper presents a finite element (FE) model to identify parameters that affect the performance of an improved cancellous bone screw fixation technique, and hence potentially improve fracture treatment. In cancellous bone of low apparent density, it can be difficult to achieve adequate screw fixation and hence provide stable fracture fixation that enables bone healing. Data from predictive FE models indicate that cements can have a significant potential to improve screw holding power in cancellous bone. These FE models are used to demonstrate the key parameters that determine pull-out strength in a variety of screw, bone and cement set-ups, and to compare the effectiveness of different configurations. The paper concludes that significant advantages, up to an order of magnitude, in screw pull-out strength in cancellous bone might be gained by the appropriate use of a currently approved calcium phosphate cement.

Bone density and the lightweight skeletons of birds.

PubMed

Dumont, Elizabeth R

2010-07-22

The skeletons of birds are universally described as lightweight as a result of selection for minimizing the energy required for flight. From a functional perspective, the weight (mass) of an animal relative to its lift-generating surfaces is a key determinant of the metabolic cost of flight. The evolution of birds has been characterized by many weight-saving adaptations that are reflected in bone shape, many of which strengthen and stiffen the skeleton. Although largely unstudied in birds, the material properties of bone tissue can also contribute to bone strength and stiffness. In this study, I calculated the density of the cranium, humerus and femur in passerine birds, rodents and bats by measuring bone mass and volume using helium displacement. I found that, on average, these bones are densest in birds, followed closely by bats. As bone density increases, so do bone stiffness and strength. Both of these optimization criteria are used in the design of strong and stiff, but lightweight, manmade airframes. By analogy, increased bone density in birds and bats may reflect adaptations for maximizing bone strength and stiffness while minimizing bone mass and volume. These data suggest that both bone shape and the material properties of bone tissue have played important roles in the evolution of flight. They also reconcile the conundrum of how bird skeletons can appear to be thin and delicate, yet contribute just as much to total body mass as do the skeletons of terrestrial mammals.

Attainment of peak bone mass at the lumbar spine, femoral neck and radius in men and women: relative contributions of bone size and volumetric bone mineral density.

PubMed

Henry, Yvette M; Fatayerji, Diana; Eastell, Richard

2004-04-01

The age at which peak bone mineral content (peak BMC) is reached remains controversial and the mechanism underlying bone mass "consolidation" is still undefined. The aims of this study were to investigate; (1) the timing of peak BMC by studying bone size and volumetric BMD (vBMD) as separate entities and (2) to determine the relative contributions of bone size and vBMD to bone mass "consolidation". A total of 132 healthy Caucasian children (63 boys and 69 girls, ages 11-19 years) and 134 healthy Caucasian adults (66 men and 68 women, ages 20-50 years) were studied. BMC was measured by DXA at the AP and lateral lumbar spine (LS) femoral neck (FN) and ultradistal radius (UDR). vBMD and bone volume (size) were estimated. Bone mass "consolidation" was examined between age 16 years to the age peak bone values were attained. During growth, BMC and bone size increased steeply with age and approximately 80-90% of peak values were achieved by late adolescence. vBMD at the spine and UDR (in women) increased gradually, but vBMD at the FN and UDR in men remained almost constant. During "consolidation", bone size continued to increase with little change in vBMD. Peak vBMD at the lumbar spine was reached at 22 and 29 years in men and women, respectively, but earlier at the FN at 12 years. At the UDR peak vBMD was achieved at age 19 years in women, with little change in men. In conclusion, peak vBMD and bone size are almost fully attained during late adolescence. Although speculative, the lack of change in vBMD during consolidation implies that the continued increase in bone mass may primarily be due to increases in bone size rather than increases in either trabecular volume, cortical thickness or the degree of mineralisation of existing bone matrix (vBMD). Skeletal growth and maturation is heterogeneous, but crucial in understanding how the origins of osteoporosis may begin during childhood and young adulthood.

Osteoconduction of impacted porous titanium particles with a calcium-phosphate coating is comparable to osteoconduction of impacted allograft bone particles: in vivo study in a nonloaded goat model.

PubMed

Walschot, Lucas H B; Aquarius, René; Schreurs, Barend W; Verdonschot, Nico; Buma, Pieter

2012-08-01

Impaction grafting restores bone defects in hip arthroplasty. Defects are reconstructed with bone particles (BoP) as substitute materials with adequate mechanical and biological properties are not yet available. Ceramic particles (CeP) have mechanical drawbacks as opposed to porous titanium particles (TiP). In this in vivo study, bone ingrowth and bone volume in coated and noncoated TiP were compared to porous biphasic calcium-phospate CeP and allograft BoP. Coatings consisted of silicated calcium-phosphate and carbonated apatite. Materials were implanted in goats and impacted in cylindrical defects (diameter 8 mm) in the cancellous bone of the femur. On the basis of fluorochrome labeling and histology, bone ingrowth distance was measured at 4, 8, and 12 weeks. Cross-sectional bone area was measured at 12 weeks. TiP created a coherent matrix of entangled particles. CeP pulverized and were noncoherent. Bone ingrowth in TiP improved significantly by the coatings to levels comparable to BoP and CeP. Cross-sectional bone area was smaller in CeP and TiP compared to BoP. The osteoconductive properties of impacted TiP with a calcium-phosphate coating are comparable to impacted allograft bone and impacted biphasic ceramics. A more realistic loaded in vivo study should prove that coated TiP is an attractive alternative to allograft bone. Copyright © 2012 Wiley Periodicals, Inc.

Nutritional Aspects of Bone Health and Fracture Healing

PubMed Central

Karpouzos, Athanasios; Diamantis, Evangelos; Farmaki, Paraskevi

2017-01-01

Introduction Fractures are quite common, especially among the elderly. However, they can increase in prevalence in younger ages too if the bone health is not good. This may happen as a result of bad nutrition. Methods A customized, retrospective review of available literature was performed using the following keywords: bone health, nutrition, and fractures. Results Insufficient intake of certain vitamins, particularly A and D, and other nutrients, such as calcium, may affect bone health or even the time and degree of bone healing in case of fracture. The importance of different nutrients, both dietary and found in food supplements, is discussed concerning bone health and fracture healing. Conclusion A healthy diet with adequate amounts of both macro- and micronutrients is essential, for both decreasing fracture risk and enhancing the healing process after fracture. PMID:29464131

Building better bone: The weaving of biologic and engineering strategies for managing bone loss.

PubMed

Schwartz, Andrew M; Schenker, Mara L; Ahn, Jaimo; Willett, Nick J

2017-09-01

Segmental bone loss remains a challenging clinical problem for orthopaedic trauma surgeons. In addition to the missing bone itself, the local tissues (soft tissue, vascular) are often highly traumatized as well, resulting in a less than ideal environment for bone regeneration. As a result, attempts at limb salvage become a highly expensive endeavor, often requiring multiple operations and necessitating the use of every available strategy (autograft, allograft, bone graft substitution, Masquelet, bone transport, etc.) to achieve bony union. A cost-sensitive, functionally appropriate, and volumetrically adequate engineered substitute would be practice-changing for orthopaedic trauma surgeons and these patients with difficult clinical problems. In tissue engineering and bone regeneration fields, numerous research efforts continue to make progress toward new therapeutic interventions for segmental bone loss, including novel biomaterial development as well as cell-based strategies. Despite an ever-evolving literature base of these new therapeutic and engineered options, there remains a disconnect with the clinical practice, with very few translating into clinical use. A symposium entitled "Building better bone: The weaving of biologic and engineering strategies for managing bone loss," was presented at the 2016 Orthopaedic Research Society Conference to further explore this engineering-clinical disconnect, by surveying basic, translational, and clinical researchers along with orthopaedic surgeons and proposing ideas for pushing the bar forward in the field of segmental bone loss. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1855-1864, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Functionally improved bone in Calbindin-D28k knockout mice

PubMed Central

Margolis, David S.; Kim, Devin; Szivek, John A.; Lai, Li-Wen; Lien, Yeong-Hau H.

2008-01-01

In vitro studies indicate that Calbindin-D28k, a calcium binding protein, is important in regulating the life span of osteoblasts as well as the mineralization of bone extracellular matrix. The recent creation of a Calbindin-D28k knockout mouse has provided the opportunity to study the physiological effects of the Calbindin-D28k protein on bone remodeling in vivo. In this experiment, histomorphometry, μCT, and bend testing were used to characterize bones in Calbindin-D28k KO (knockout) mice. The femora of Calbindin-D28k KO mice had significantly increased cortical bone volume (60.4% ± 3.1) compared to wild-type (WT) mice (45.4% ± 4.6). The increased bone volume was due to a decrease in marrow cavity area, and significantly decreased endosteal perimeters (3.397 mm ± 0.278 in Calbindin-D28k KO mice, and 4.046 mm ± 0.450 in WT mice). Similar changes were noted in the analysis of the tibias in both mice. The bone formation rates were similar in the femoral and tibial cortical bones of both mice. μCT analysis of the trabecular bone in the tibial plateau indicated that Calbindin-D28k KO mice had an increased bone volume (35.2% ± 3.1) compared to WT mice (24.7% ± 4.9) which was primarily due to increased trabecular number (8.99 mm−1 ± 0.94 in Calbindin-D28k KO mice compared to 6.75 mm−1 ± 0.85 in WT mice). Bone mineral content analysis of the tibias indicated that there is no difference in the calcium or phosphorus content between the Calbindin-D28k KO and WT mice. Cantilever bend testing of the femora demonstrated significantly lower strains in the bones of Calbindin-D28k KO mice (4135 μstrain/kg ± 1266) compared to WT mice (6973 μstrain/kg ± 998) indicating that the KO mice had stiffer bones. Three-point bending demonstrated increased failure loads in bones of Calbindin-D28k KO mice (31.6 N ± 2.1) compared to WT mice (15.0 N ± 1.7). In conclusion, Calbindin-D28k KO mice had increased bone volume and stiffness indicating that Calbindin-D28k plays an

Bone Engineering of Maxillary Sinus Bone Deficiencies Using Enriched CD90+ Stem Cell Therapy: A Randomized Clinical Trial.

PubMed

Kaigler, Darnell; Avila-Ortiz, Gustavo; Travan, Suncica; Taut, Andrei D; Padial-Molina, Miguel; Rudek, Ivan; Wang, Feng; Lanis, Alejandro; Giannobile, William V

2015-07-01

Bone engineering of localized craniofacial osseous defects or deficiencies by stem cell therapy offers strong prospects to improve treatment predictability for patient care. The aim of this phase 1/2 randomized, controlled clinical trial was to evaluate reconstruction of bone deficiencies of the maxillary sinus with transplantation of autologous cells enriched with CD90+ stem cells and CD14+ monocytes. Thirty human participants requiring bone augmentation of the maxillary sinus were enrolled. Patients presenting with 50% to 80% bone deficiencies of the maxillary sinus were randomized to receive either stem cells delivered onto a β-tricalcium phosphate scaffold or scaffold alone. Four months after treatment, clinical, radiographic, and histologic analyses were performed to evaluate de novo engineered bone. At the time of alveolar bone core harvest, oral implants were installed in the engineered bone and later functionally restored with dental tooth prostheses. Radiographic analyses showed no difference in the total bone volume gained between treatment groups; however, density of the engineered bone was higher in patients receiving stem cells. Bone core biopsies showed that stem cell therapy provided the greatest benefit in the most severe deficiencies, yielding better bone quality than control patients, as evidenced by higher bone volume fraction (BVF; 0.5 versus 0.4; p = 0.04). Assessment of the relation between degree of CD90+ stem cell enrichment and BVF showed that the higher the CD90 composition of transplanted cells, the greater the BVF of regenerated bone (r = 0.56; p = 0.05). Oral implants were placed and restored with functionally loaded dental restorations in all patients and no treatment-related adverse events were reported at the 1-year follow-up. These results provide evidence that cell-based therapy using enriched CD90+ stem cell populations is safe for maxillary sinus floor reconstruction and offers potential to accelerate and enhance

The potential role of free chitosan in bone trauma and bone cancer management.

PubMed

Tan, Mei L; Shao, Peng; Friedhuber, Anna M; van Moorst, Mallory; Elahy, Mina; Indumathy, Sivanjah; Dunstan, Dave E; Wei, Yongzhong; Dass, Crispin R

2014-09-01

Bone defects caused by fractures or cancer-mediated destruction are debilitating. Chitosan is commonly used in scaffold matrices for bone healing, but rarely as a free drug. We demonstrate that free chitosan promotes osteoblast proliferation and osteogenesis in mesenchymal stem cells, increases osteopontin and collagen I expression, and reduces osteoclastogenesis. Chitosan inhibits invasion of endothelial cells, downregulating uPA/R, MT1-MMP, cdc42 and Rac1. Better healing of bone fractures with greater trabecular bone formation was observed in mice treated with chitosan. Chitosan induces apoptosis in osteotropic prostate and breast cancer cells via caspase-2 and -3 activation, and reduces their establishment in bone. Chitosan is pro-apoptotic in osteosarcoma cells, but not their normal counterpart, osteoblasts, or chondrosarcoma cells. Systemic delivery of chitosan does not perturb angiogenesis, bone volume or instinctive behaviour in pregnant mice, but decreases foetal length and changes pancreatic secretory acini. With certain controls in place, chitosan could be useful for bone trauma management. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation of novel resorbable membranes for bone augmentation in a rat model.

PubMed

Zeng, Ni; van Leeuwen, Anne; Yuan, Huipin; Bos, Ruud R M; Grijpma, Dirk W; Kuijer, Roel

2016-02-01

Our study compared two novel, biodegradable poly(trimethylene carbonate) (PTMC) barrier membranes to clinically applied barrier membranes in maintaining volume of block autologous bone grafts in a rat mandible model. Two hundred and forty rats were included in this study. Block autologous bone grafts of 5 mm in diameter were harvested from the mandibular angles and transplanted onto the contralateral side. The bone grafts were either covered with a membrane or left uncovered. The applied membranes included pure PTMC membranes, biphasic calcium phosphate (BCP) incorporated PTMC composite membranes, expanded poly(tetrafluoroethylene) (e-PTFE) membranes (Tex) and collagen membranes (Geistlich Bio-Gide). After 2, 4 and 12 weeks, the rat mandibles were retrieved and analysed by histological evaluation and μCT quantification. The histological evaluation revealed that in time the block autologous bone graft was well integrated to the recipient bone via gradually maturing newly formed bone and did not show signs of resorption, independent of membrane coverage or types of membrane. μCT quantification showed the volume of the bone graft and recipient bone together was maintained by new bone formation and recipient bone resorption. Our study showed that the use of PTMC membranes and PTMC-BCP composite membranes resulted in similar bone remodelling to the collagen membranes and e-PTFE membranes and that the use of barrier membranes did not interfere with bone remodelling of the bone grafts and recipient bones. However, the used barrier membranes seemed not to contribute in maintaining the volume of block autologous bone grafts. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Appliance-induced osteopenia of dentoalveolar bone in the rat: effect of reduced bone strains on serum bone markers and the multifunctional hormone leptin.

PubMed

Vinoth, Jayaseelan K; Patel, Kaval J; Lih, Wei-Song; Seow, Yian-San; Cao, Tong; Meikle, Murray C

2013-12-01

To understand, in greater detail, the molecular mechanisms regulating the complex relationship between mechanical strain and alveolar bone metabolism during orthodontic treatment, passive cross-arch palatal springs were bonded to the maxillary molars of 6-wk-old rats, which were killed after 4 and 8 d. Outcome measures included serum assays for markers of bone formation and resorption and for the multifunctional hormone leptin, and histomorphometry of the inter-radicular bone. The concentration of the bone-formation marker alkaline phosphatase (ALP) was significantly reduced at both time points in the appliance group, accompanied by a 50% reduction in inter-radicular bone volume; however, osteocalcin (bone Gla protein) levels remained unaffected. Bone collagen deoxypyridinoline (DPD) crosslinks increased 2.3-fold at 4 d only, indicating a transient increase in bone resorption; in contrast, the level of the osteoclast-specific marker, tartrate-resistant acid phosphatase 5b (TRACP 5b), was unchanged. Leptin levels closely paralleled ALP reductions at both time points, suggesting an important role in the mechanostat negative-feedback loop required to normalize bone mass. These data suggest that an orthodontic appliance, in addition to remodeling the periodontal ligament (PDL)-bone interface, may exert unexpected side-effects on the tooth-supporting alveolar bone, and highlights the importance of recognizing that bone strains can have negative, as well as positive, effects on bone mass. © 2013 Eur J Oral Sci.

Suppressed bone remodeling in black bears conserves energy and bone mass during hibernation

PubMed Central

McGee-Lawrence, Meghan; Buckendahl, Patricia; Carpenter, Caren; Henriksen, Kim; Vaughan, Michael; Donahue, Seth

2015-01-01

ABSTRACT 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. PMID:26157160

Nonlinear hierarchical multiscale modeling of cortical bone considering its nanoscale microstructure.

PubMed

Ghanbari, J; Naghdabadi, R

2009-07-22

We have used a hierarchical multiscale modeling scheme for the analysis of cortical bone considering it as a nanocomposite. This scheme consists of definition of two boundary value problems, one for macroscale, and another for microscale. The coupling between these scales is done by using the homogenization technique. At every material point in which the constitutive model is needed, a microscale boundary value problem is defined using a macroscopic kinematical quantity and solved. Using the described scheme, we have studied elastic properties of cortical bone considering its nanoscale microstructural constituents with various mineral volume fractions. Since the microstructure of bone consists of mineral platelet with nanometer size embedded in a protein matrix, it is similar to the microstructure of soft matrix nanocomposites reinforced with hard nanostructures. Considering a representative volume element (RVE) of the microstructure of bone as the microscale problem in our hierarchical multiscale modeling scheme, the global behavior of bone is obtained under various macroscopic loading conditions. This scheme may be suitable for modeling arbitrary bone geometries subjected to a variety of loading conditions. Using the presented method, mechanical properties of cortical bone including elastic moduli and Poisson's ratios in two major directions and shear modulus is obtained for different mineral volume fractions.

Assessment of image quality in soft tissue and bone visualization tasks for a dedicated extremity cone-beam CT system.

PubMed

Demehri, S; Muhit, A; Zbijewski, W; Stayman, J W; Yorkston, J; Packard, N; Senn, R; Yang, D; Foos, D; Thawait, G K; Fayad, L M; Chhabra, A; Carrino, J A; Siewerdsen, J H

2015-06-01

To assess visualization tasks using cone-beam CT (CBCT) compared to multi-detector CT (MDCT) for musculoskeletal extremity imaging. Ten cadaveric hands and ten knees were examined using a dedicated CBCT prototype and a clinical multi-detector CT using nominal protocols (80 kVp-108mAs for CBCT; 120 kVp- 300 mAs for MDCT). Soft tissue and bone visualization tasks were assessed by four radiologists using five-point satisfaction (for CBCT and MDCT individually) and five-point preference (side-by-side CBCT versus MDCT image quality comparison) rating tests. Ratings were analyzed using Kruskal-Wallis and Wilcoxon signed-rank tests, and observer agreement was assessed using the Kappa-statistic. Knee CBCT images were rated "excellent" or "good" (median scores 5 and 4) for "bone" and "soft tissue" visualization tasks. Hand CBCT images were rated "excellent" or "adequate" (median scores 5 and 3) for "bone" and "soft tissue" visualization tasks. Preference tests rated CBCT equivalent or superior to MDCT for bone visualization and favoured the MDCT for soft tissue visualization tasks. Intraobserver agreement for CBCT satisfaction tests was fair to almost perfect (κ ~ 0.26-0.92), and interobserver agreement was fair to moderate (κ ~ 0.27-0.54). CBCT provided excellent image quality for bone visualization and adequate image quality for soft tissue visualization tasks. • CBCT provided adequate image quality for diagnostic tasks in extremity imaging. • CBCT images were "excellent" for "bone" and "good/adequate" for "soft tissue" visualization tasks. • CBCT image quality was equivalent/superior to MDCT for bone visualization tasks.

Bone histomorphometry using free and commonly available software.

PubMed

Egan, Kevin P; Brennan, Tracy A; Pignolo, Robert J

2012-12-01

Histomorphometric analysis is a widely used technique to assess changes in tissue structure and function. Commercially available programs that measure histomorphometric parameters can be cost-prohibitive. In this study, we compared an inexpensive method of histomorphometry to a current proprietary software program. Image J and Adobe Photoshop(®) were used to measure static and kinetic bone histomorphometric parameters. Photomicrographs of Goldner's trichrome-stained femurs were used to generate black-and-white image masks, representing bone and non-bone tissue, respectively, in Adobe Photoshop(®) . The masks were used to quantify histomorphometric parameters (bone volume, tissue volume, osteoid volume, mineralizing surface and interlabel width) in Image J. The resultant values obtained using Image J and the proprietary software were compared and differences found to be statistically non-significant. The wide-ranging use of histomorphometric analysis for assessing the basic morphology of tissue components makes it important to have affordable and accurate measurement options available for a diverse range of applications. Here we have developed and validated an approach to histomorphometry using commonly and freely available software that is comparable to a much more costly, commercially available software program. © 2012 Blackwell Publishing Limited.

Bone histomorphometry using free and commonly available software

PubMed Central

Egan, Kevin P.; Brennan, Tracy A.; Pignolo, Robert J.

2012-01-01

Aims Histomorphometric analysis is a widely used technique to assess changes in tissue structure and function. Commercially-available programs that measure histomorphometric parameters can be cost prohibitive. In this study, we compared an inexpensive method of histomorphometry to a current proprietary software program. Methods and results Image J and Adobe Photoshop® were used to measure static and kinetic bone histomorphometric parameters. Photomicrographs of Goldner’s Trichrome stained femurs were used to generate black and white image masks, representing bone and non-bone tissue, respectively, in Adobe Photoshop®. The masks were used to quantify histomorphometric parameters (bone volume, tissue volume, osteoid volume, mineralizing surface, and interlabel width) in Image J. The resultant values obtained using Image J and the proprietary software were compared and found to be statistically non-significant. Conclusions The wide ranging use of histomorphometric analysis for assessing the basic morphology of tissue components makes it important to have affordable and accurate measurement options that are available for a diverse range of applications. Here we have developed and validated an approach to histomorphometry using commonly and freely available software that is comparable to a much more costly, commercially-available software program. PMID:22882309

[Guided bone regeneration: general survey].

PubMed

Cosyn, Jan; De Bruyn, Hugo

2009-01-01

The principle of 'guided bone regeneration' was first described in 1988 on the basis of animal-experimental data. Six weeks after transmandibular defects had been created and protected by non-resorbable teflonmembranes, complete bone regeneration was found. The technique was based on the selective repopulation of the wound: every infiltration of cells outside the neighbouring bone tissue was prevented by the application of the membrane. Additional animal experiments showed that guided bone regeneration was a viable treatment option for local bone defects surrounding dental implants. Clinical practice, however, showed that premature membrane exposure was a common complication, which was responsible for a tremendous reduction in regenerated bone volume. In addition, a second surgical intervention was always necessary to remove the membrane. As a result, resorbable alternatives were developed. Since these are less rigid, bone fillers are usually used simultaneously. These comprise autogenous bone chips and bone substitutes from allogenic or xenogenic origine. Also alloplastic materials could be used for this purpose. Based on their characteristics this article provides an overview of the biomaterials that could be considered for guided bone regeneration. Specific attention goes to their application in clinical practice.

Associations among endocrine, inflammatory, and bone markers, body composition and weight loss induced bone loss.

PubMed

Labouesse, Marie A; Gertz, Erik R; Piccolo, Brian D; Souza, Elaine C; Schuster, Gertrud U; Witbracht, Megan G; Woodhouse, Leslie R; Adams, Sean H; Keim, Nancy L; Van Loan, Marta D

2014-07-01

Weight loss reduces co-morbidities of obesity, but decreases bone mass. Our aims were to (1) determine if adequate dairy intake attenuates weight loss-induced bone loss; (2) evaluate the associations of endocrine, inflammatory and bone markers, anthropometric and other parameters to bone mineral density and content (BMD, BMC) pre- and post-weight loss; and (3) model the contribution of these variables to post weight-loss BMD and BMC. Overweight/obese women (BMI: 28-37 kg/m2) were enrolled in an energy reduced (-500 kcal/d; -2092 kJ/d) diet with adequate dairy (AD: 3-4 servings/d; n=25, 32.2±8.8 years) or low dairy (LD: ≤1 serving/d; n=26, 31.7±8.4 years). BMD, BMC and body composition were measured by DXA. Bone markers (CTX, PYD, BAP, OC), endocrine (PTH, vitamin D, leptin, adiponectin, ghrelin, amylin, insulin, GLP-1, PAI-1, HOMA) and inflammatory markers (CRP, IL1-β, IL-6, IL-8, TNF-α, cortisol) were measured in serum or plasma. PA was assessed by accelerometry. Following weight loss, AD intake resulted in significantly greater (p=0.004) lumbar spine BMD and serum osteocalcin (p=0.004) concentration compared to LD. Pre- and post-body fat was negatively associated with hip and lumbar spine BMC (r=-0.28, p=0.04 to -0.45, p=0.001). Of note were the significant negative associations among bone markers and IL-1β, TNFα and CRP ranging from r = -0.29 (p=0.04) to r = -0.34 (p=0.01); magnitude of associations did not change with weight loss. Adiponectin was negatively related to change in osteocalcin. Factor analysis resulted in 8 pre- and post-weight loss factors. Pre-weight loss factors accounted for 13.7% of the total variance in pre-weight loss hip BMD; post-weight loss factors explained 19.6% of the total variance in post-weight loss hip BMD. None of the factors contributed to the variance in lumbar spine BMD. AD during weight loss resulted in higher lumbar spine BMD and osteocalcin compared to LD. Significant negative associations were observed between bone

Increasing the amount of corticotomy does not affect orthodontic tooth movement or root resorption, but accelerates alveolar bone resorption in rats.

PubMed

Kurohama, Takeshi; Hotokezaka, Hitoshi; Hashimoto, Megumi; Tajima, Takako; Arita, Kotaro; Kondo, Takanobu; Ino, Airi; Yoshida, Noriaki

2017-06-01

The purpose of this study was to evaluate the relationships among the volume of bone cut during corticotomy, amount of tooth movement, volume of root resorption, and volume of the resultant alveolar bone resorption after tooth movement. Ten-week-old female Wistar rats were distributed into the corticotomy groups and a control group that underwent sham corticotomy. Two experiments employing two different orthodontic forces (10 or 25g) and experimental periods (14 or 21 days) were performed. The volumes of the bone cut by corticotomy were 0.1, 1.0, and 1.7mm3 in the 25g groups, and 1.0 and 1.7mm3 in the 10g groups. Nickel-titanium closed-coil springs were set on the maxillary left first molars to induce mesial movement. After orthodontic tooth movement, the amount of tooth movement, volume of root resorption, and volume of alveolar bone resorption were measured. Despite differences in the volume of bone cut among the different corticotomy groups, there were not significant differences in the amount of tooth movement and volume of root resorption between the control group and any of the corticotomy groups. However, higher volume of bone cut during corticotomy was significantly related to the decreased alveolar bone volume-in particular, to the reduced height of the alveolar bone crest after tooth movement. The volume of the alveolar bone cut during corticotomy does not affect tooth movement or root resorption in 10-week-old female Wistar rats; however, it may increase alveolar bone loss after tooth movement. © The Author 2016. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com

Quantitative and qualitative analysis of bone flap resorption in patients undergoing cranioplasty after decompressive craniectomy.

PubMed

Korhonen, Tommi K; Salokorpi, Niina; Niinimäki, Jaakko; Serlo, Willy; Lehenkari, Petri; Tetri, Sami

2018-02-23

OBJECTIVE Autologous bone cranioplasty after decompressive craniectomy entails a notable burden of difficult postoperative complications, such as infection and bone flap resorption (BFR), leading to mechanical failure. The prevalence and significance of asymptomatic BFR is currently unclear. The aim of this study was to radiologically monitor the long-term bone flap survival and bone quality change in patients undergoing autologous cranioplasty. METHODS The authors identified all 45 patients who underwent autologous cranioplasty at Oulu University Hospital, Finland, between January 2004 and December 2014. Using perioperative and follow-up CT scans, the volumes and radiodensities of the intact bone flap prior to surgery and at follow-up were calculated. Relative changes in bone flap volume and radiodensity were then determined to assess cranioplasty survival. Sufficient CT scans were obtainable from 41 (91.1%) of the 45 patients. RESULTS The 41 patients were followed up for a median duration of 3.79 years (25th and 75th percentiles = 1.55 and 6.66). Thirty-seven (90.2%) of the 41 patients had some degree of BFR and 13 (31.7%) had a remaining bone flap volume of less than 80%. Patients younger than 30 years of age had a mean decrease of 15.8% in bone flap volume compared with the rest of the cohort. Bone flap volume was not found to decrease linearly with the passing of time, however. The effects of lifestyle factors and comorbidities on BFR were nonsignificant. CONCLUSIONS In this study BFR was a very common phenomenon, occurring at least to some degree in 90% of the patients. Decreases in bone volume were especially prominent in patients younger than 30 years of age. Because the progression of resorption during follow-up was nonlinear, routine follow-up CT scans appear unnecessary in monitoring the progression of BFR; instead, clinical follow-up with mechanical stability assessment is advised. Partial resorption is most likely a normal physiological phenomenon

Radiographic and Histologic Evaluation of a Bone Void that Formed After Recombinant Human Bone Morphogenetic Protein-2-Mediated Sinus Graft Augmentation: A Case Report.

PubMed

Kang, Hyun-Joo; Jun, Choong-Man; Yun, Jeong-Ho

2016-01-01

In the present case report, the authors describe radiographic and histologic observations of a bone void that formed after a sinus augmentation using a graft material that contained recombinant human bone morphogenetic protein-2 (rhBMP-2) and discuss clinical and histologic implications of their findings. Sinus augmentation was performed using a graft material comprising 1 g of hydroxyapatite/β-tricalcium phosphate, which contained 1 mg of rhBMP-2. Radiographic evaluation was conducted with panoramic radiographs and computed tomography images of the augmented maxillary sinus, which were analyzed using a three-dimensional image-reconstruction program. Histologic evaluation was also performed on a biopsy specimen obtained 6 months after the sinus augmentation. The total augmented volume increased from 1,582.2 mm(3) immediately after the sinus augmentation to 3,344.9 mm3 at 6 months after the augmentation because of the formation of a bone void. Twenty-six months after the sinus augmentation, the bone void remained but had reduced in volume, with the total augmented volume reduced to 2,551.7 mm(3). Histologically, new bone was observed to be in contact with the grafted particles, and a fatty marrow-like tissue was present in the area of the bone void. This case report shows that the bone void that had formed after sinus augmentation resolved over time and seemed to be partially replaced with new bone. Furthermore, none of the implants failed, and clinical adverse events were not observed during the follow-up period.

BMP delivery complements the guiding effect of scaffold architecture without altering bone microstructure in critical-sized long bone defects: A multiscale analysis.

PubMed

Cipitria, A; Wagermaier, W; Zaslansky, P; Schell, H; Reichert, J C; Fratzl, P; Hutmacher, D W; Duda, G N

2015-09-01

Scaffold architecture guides bone formation. However, in critical-sized long bone defects additional BMP-mediated osteogenic stimulation is needed to form clinically relevant volumes of new bone. The hierarchical structure of bone determines its mechanical properties. Yet, the micro- and nanostructure of BMP-mediated fast-forming bone has not been compared with slower regenerating bone without BMP. We investigated the combined effects of scaffold architecture (physical cue) and BMP stimulation (biological cue) on bone regeneration. It was hypothesized that a structured scaffold directs tissue organization through structural guidance and load transfer, while BMP stimulation accelerates bone formation without altering the microstructure at different length scales. BMP-loaded medical grade polycaprolactone-tricalcium phosphate scaffolds were implanted in 30mm tibial defects in sheep. BMP-mediated bone formation after 3 and 12 months was compared with slower bone formation with a scaffold alone after 12 months. A multiscale analysis based on microcomputed tomography, histology, polarized light microscopy, backscattered electron microscopy, small angle X-ray scattering and nanoindentation was used to characterize bone volume, collagen fiber orientation, mineral particle thickness and orientation, and local mechanical properties. Despite different observed kinetics in bone formation, similar structural properties on a microscopic and sub-micron level seem to emerge in both BMP-treated and scaffold only groups. The guiding effect of the scaffold architecture is illustrated through structural differences in bone across different regions. In the vicinity of the scaffold increased tissue organization is observed at 3 months. Loading along the long bone axis transferred through the scaffold defines bone micro- and nanostructure after 12 months. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Comparison between autogenous iliac bone and freeze-dried bone allograft for repair of alveolar clefts in the presence of plasma rich in growth factors: A randomized clinical trial.

PubMed

Shirani, Gholamreza; Abbasi, Amir J; Mohebbi, Simin Z; Moharrami, Mohammad

2017-10-01

This study aimed to compare the effectiveness of alveolar cleft repair using iliac bone and freeze-dried bone allograft (FDBA) in the presence of plasma rich in growth factors (PRGF). Patients with unilateral alveolar cleft (n = 32) were randomly allocated to either the iliac plus PRGF group or the FDBA plus PRGF group. CBCT images were obtained before and 6 months after the surgery to assess the regenerated bone volume. Paired t-tests and two-way analysis of variance (ANOVA) were applied to analyze the data using SPSS 16.0 software. The patients' mean age was 15 ± 5.7 years (range = 8-27). In the iliac plus PRGF group, the mean volume of cleft before the surgery and the mean regenerated bone volume 6 months after were 1.67 ± 0.66 and 1.14 ± 0.47 cm 3 , respectively. The corresponding values were 1.5 ± 0.54 and 0.72 ± 0.23 cm 3 in the FDBA plus PRGF group. The remaining bone to cleft volume ratio was not associated with grafting time (secondary or tertiary) and the original cleft volume. Iliac bone reinforced with PRGF was more successful than FDBA plus PRGF in repairing alveolar cleft (p = 0.007). Due to the poor performance of the allograft, autografts should still be preferred in spite of possible donor site morbidity. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Fortified tuna bone powder supplementation increases bone mineral density of lactating rats and their offspring.

PubMed

Suntornsaratoon, Panan; Charoenphandhu, Narattaphol; Krishnamra, Nateetip

2018-03-01

Breastfeeding leads to bone calcium loss for milk production, resulting in progressive maternal osteopenia. Calcium supplement from natural sources has been postulated to be more beneficial to bone health than purified CaCO 3 because natural sources also contain other nutrients such as certain amino acids that might enhance calcium metabolism. Herein, we examined the effect of calcium supplementation from tuna bone powder and CaCO 3 on bones of dams and the offspring. Both forms of calcium supplement, i.e. tuna bone powder and CaCO 3 , increased maternal bone mineral density (BMD). However, bone histomorphometry revealed that only tuna bone had beneficial effect on maternal bone microstructure, i.e. increased bone formation, decreased bone resorption and increased in bone volume. Regarding the mechanical properties, the decreased ultimate load in non-supplement lactating mothers was restored to the load seen in nulliparous animals by calcium supplementation. Moreover, both tuna bone and CaCO 3 supplementation in mothers led to increased milk calcium concentration and consequently increased BMD in the growing offspring. Calcium supplement from tuna bone powder was effective in preventing maternal osteopenia. Tuna bone, which is a readily available fishing industrial waste, is a good alternative source of calcium supplement that increases BMD in both lactating mothers and the neonates. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Bone microarchitecture and estimated bone strength in men with active acromegaly.

PubMed

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  < 0.0001), cortical thickness ( P  = 0.0038), cortical pore volume ( P  < 0.0001) and cortical porosity ( P  = 0.0008), but lower trabecular bone density ( P  = 0.0010) compared to controls. At the tibia, patients with 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.

Brown Adipose Tissue and Its Relationship to Bone Structure in Pediatric Patients

PubMed Central

Ponrartana, Skorn; Aggabao, Patricia C.; Hu, Houchun H.; Aldrovandi, Grace M.; Wren, Tishya A. L.

2012-01-01

Context: Emerging evidence suggests a possible link between brown adipose tissue (BAT) and bone metabolism. Objective: The objective of this study was to examine the relationships between BAT and bone cross-sectional dimensions in children and adolescents. Design: This was a cross-sectional study. Setting: The study was conducted at a pediatric referral center. Patients: Patients included 40 children and teenagers (21 males and 19 females) successfully treated for pediatric malignancies. Interventions: There were no interventions. Main Outcome Measures: The volume of BAT was determined by fluorodeoxyglucose-positron emission tomography/computed tomography. Measures of the cross-sectional area and cortical bone area and measures of thigh musculature and sc fat were determined at the midshaft of the femur. Results: Regardless of sex, there were significant correlations seen between BAT volume and the cross-sectional dimensions of the bone (r values between 0.68 and 0.77; all P ≤ 0 .001). Multiple regression analyses indicated that the volume of BAT predicted femoral cross-sectional area and cortical bone area, even after accounting for height, weight, and gender. The addition of muscle as an independent variable increased the predictive power of the model but significantly decreased the contribution of BAT. Conclusions: The volume of BAT is positively associated with the amount of bone and the cross-sectional size of the femur in children and adolescents. This relation between BAT and bone structure could, at least in part, be mediated by muscle. PMID:22593587

Prostate Cancer Metastases Alter Bone Mineral and Matrix Composition Independent of Effects on Bone Architecture in Mice A Quantitative Study Using microCT and Raman Spectroscopy

PubMed Central

Bi, Xiaohong; Sterling, Julie A.; Merkel, Alyssa R.; Perrien, Daniel S.; Nyman, Jeffry; Mahadevan-Jansen, Anita

2013-01-01

Prostate cancer is the most common primary tumor and the second leading cause of cancer-related deaths in men in the United States. Prostate cancer bone metastases are characterized by abnormal bone remodeling processes and result in a variety of skeletal morbidities. Prevention of skeletal complications is a crucial element in prostate cancer management. This study investigated prostate cancer-induced alterations in the molecular composition and morphological structure of metastasis-bearing bones in a mouse model of prostate cancer using Raman spectroscopy and micro-computed tomography (microCT). LNCaP C4-2B prostate cancer cells were injected into the right tibiae of 5-week old male SCID mice. Upon sacrifice at 8 weeks post tumor inoculation, two out of the ten tumor-bearing tibiae showed only osteoblastic lesions in the radiographs, 4 osteolytic lesions only and 4 mixed with osteoblastic and osteolytic lesions.. Carbonate substitution was significantly increased while there was a marked reduction in the level of collagen mineralization, mineral crystallinity, and carbonate:matrix ratio in the cortex of the intact tumor-bearing tibiae compared to contralateral controls. MicroCT analysis revealed a significant reduction in bone volume/total volume, trabecular number and trabecular thickness, as well as significant increase in bone surface/volume ratio in tibiae with osteolytic lesions, suggesting active bone remodeling and bone loss. None of the changes in bone compositional properties were correlated with lesion area from radiographs or the changes in bone architecture from microCT. This study indicates that LNCaP C4-2B prostate cancer metastases alter bone tissue composition independent of changes in architecture, and altered bone quality may be an important contributor to fracture risk in these patients. Raman spectroscopy may provide a new avenue of investigation into interactions between tumor and bone microenvironment. PMID:23867219

Micro-CT evaluation of bone defects: applications to osteolytic bone metastases, bone cysts, and fracture.

PubMed

Buie, Helen R; Bosma, Nick A; Downey, Charlene M; Jirik, Frank R; Boyd, Steven K

2013-11-01

Bone defects can occur in various forms and present challenges to performing a standard micro-CT evaluation of bone quality because most measures are suited to homogeneous structures rather than ones with spatially focal abnormalities. Such defects are commonly associated with pain and fragility. Research involving bone defects requires quantitative approaches to be developed if micro-CT is to be employed. In this study, we demonstrate that measures of inter-microarchitectural bone spacing are sensitive to the presence of focal defects in the proximal tibia of two distinctly different mouse models: a burr-hole model for fracture healing research, and a model of osteolytic bone metastases. In these models, the cortical and trabecular bone compartments were both affected by the defect and were, therefore, evaluated as a single unit to avoid splitting the defects into multiple analysis regions. The burr-hole defect increased mean spacing (Sp) by 27.6%, spacing standard deviation (SpSD) by 113%, and maximum spacing (Spmax) by 72.8%. Regression modeling revealed SpSD (β=0.974, p<0.0001) to be a significant predictor of the defect volume (R(2)=0.949) and Spmax (β=0.712, p<0.0001) and SpSD (β=0.271, p=0.022) to be significant predictors of the defect diameter (R(2)=0.954). In the mice with osteolytic bone metastases, spacing parameters followed similar patterns of change as reflected by other imaging technologies, specifically bioluminescence data which is indicative of tumor burden. These data highlight the sensitivity of spacing measurements to bone architectural abnormalities from 3D micro-CT data and provide a tool for quantitative evaluation of defects within a bone. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

[Interventional radiology for bone metastases].

PubMed

Iannessi, Antoine; Garnon, Julien; Cormier, Évelyne; Clarencon, Frédéric; Chiras, Jacques

2013-11-01

The management of bone metastases requires a multidisciplinary staff to include systemic and local treatments like radiotherapy, surgery or interventional radiology (IR). Patients are often fragile. Imaging allows safe guidance to create "mini-invasive" procedures under adequate anesthesia. Patients' selection is important. If the goal is pain relief, cementoplasty provides a very effective bone consolidation and pain control. Simple and low-risk, vertebroplasty is the technique of choice in case of lytic bone metastases with spinal fracture risk or after failure of analgesic radiotherapy. If the medical project is curative, the tumor ablation procedures are realised through thermic or embolic techniques. After 60°C, the heat induces a coagulative necrose. Under -20°C, the cold leads to destroy the tissues. The major advantage of the cryotherapy is the predictibility of the ablation zone due to the well-visualized ice ball on perprocedural images. This technique is much more adapted to spare the nervous structures closed to the metastasis. The development of these new techniques of IR will treat bone metastases earlier, sometimes asymptomatic and thus improves the quality of life in patients with bone metastases.

Is bone transplantation the gold standard for repair of alveolar bone defects?

PubMed

Raposo-Amaral, Cassio Eduardo; Bueno, Daniela Franco; Almeida, Ana Beatriz; Jorgetti, Vanda; Costa, Cristiane Cabral; Gouveia, Cecília Helena; Vulcano, Luiz Carlos; Fanganiello, Roberto D; Passos-Bueno, Maria Rita; Alonso, Nivaldo

2014-01-01

New strategies to fulfill craniofacial bone defects have gained attention in recent years due to the morbidity of autologous bone graft harvesting. We aimed to evaluate the in vivo efficacy of bone tissue engineering strategy using mesenchymal stem cells associated with two matrices (bovine bone mineral and α-tricalcium phosphate), compared to an autologous bone transfer. A total of 28 adult, male, non-immunosuppressed Wistar rats underwent a critical-sized osseous defect of 5 mm diameter in the alveolar region. Animals were divided into five groups. Group 1 (n = 7) defects were repaired with autogenous bone grafts; Group 2 (n = 5) defects were repaired with bovine bone mineral free of cells; Group 3 (n = 5) defects were repaired with bovine bone mineral loaded with mesenchymal stem cells; Group 4 (n = 5) defects were repaired with α-tricalcium phosphate free of cells; and Group 5 (n = 6) defects were repaired with α-tricalcium phosphate loaded with mesenchymal stem cells. Groups 2-5 were compared to Group 1, the reference group. Healing response was evaluated by histomorphometry and computerized tomography. Histomorphometrically, Group 1 showed 60.27% ± 16.13% of bone in the defect. Groups 2 and 3 showed 23.02% ± 8.6% (p = 0.01) and 38.35% ± 19.59% (p = 0.06) of bone in the defect, respectively. Groups 4 and 5 showed 51.48% ± 11.7% (p = 0.30) and 61.80% ± 2.14% (p = 0.88) of bone in the defect, respectively. Animals whose bone defects were repaired with α-tricalcium phosphate and mesenchymal stem cells presented the highest bone volume filling the defects; both were not statistically different from autogenous bone.

Bone health. New role for vitamin K?

PubMed Central

Ryan-Harshman, Milly; Aldoori, Walid

2004-01-01

OBJECTIVE: To assess growing evidence that vitamin K (phylloquinone) plays an important role in bone health and, subsequently, in prevention of osteoporotic fractures. QUALITY OF EVIDENCE: We searched MEDLINE from January 1972 to December 2002 using the key words vitamin K and bone health. We reviewed 30 articles that seemed relevant or had a human focus. All evidence can be categorized as level II. MAIN MESSAGE: Evidence suggests that dietary phylloquinone intake of <100 microg daily might not be optimal for bone health. Low intake of vitamin K could contribute to osteoporosis and subsequent fracture due to the undercarboxylation of osteocalcin. CONCLUSION: Family physicians need to be aware of the importance of encouraging adequate vitamin K intake, particularly among institutionalized elderly people, to prevent increased bone resorption. Further study is needed to determine the exact role of vitamin K in bone metabolism, and methods of assessing vitamin K requirements need to be standardized. PMID:15317231

Three-Dimensional Geometric Analysis of Felid Limb Bone Allometry

PubMed Central

Doube, Michael; Conroy, Alexis Wiktorowicz; Christiansen, Per; Hutchinson, John R.; Shefelbine, Sandra

2009-01-01

Background Studies of bone allometry typically use simple measurements taken in a small number of locations per bone; often the midshaft diameter or joint surface area is compared to body mass or bone length. However, bones must fulfil multiple roles simultaneously with minimum cost to the animal while meeting the structural requirements imposed by behaviour and locomotion, and not exceeding its capacity for adaptation and repair. We use entire bone volumes from the forelimbs and hindlimbs of Felidae (cats) to investigate regional complexities in bone allometry. Method/Principal Findings Computed tomographic (CT) images (16435 slices in 116 stacks) were made of 9 limb bones from each of 13 individuals of 9 feline species ranging in size from domestic cat (Felis catus) to tiger (Panthera tigris). Eleven geometric parameters were calculated for every CT slice and scaling exponents calculated at 5% increments along the entire length of each bone. Three-dimensional moments of inertia were calculated for each bone volume, and spherical radii were measured in the glenoid cavity, humeral head and femoral head. Allometry of the midshaft, moments of inertia and joint radii were determined. Allometry was highly variable and related to local bone function, with joint surfaces and muscle attachment sites generally showing stronger positive allometry than the midshaft. Conclusions/Significance Examining whole bones revealed that bone allometry is strongly affected by regional variations in bone function, presumably through mechanical effects on bone modelling. Bone's phenotypic plasticity may be an advantage during rapid evolutionary divergence by allowing exploitation of the full size range that a morphotype can occupy. Felids show bone allometry rather than postural change across their size range, unlike similar-sized animals. PMID:19270749

Correlation between gamma glutamyltransferase fractions and bone quality.

PubMed

Franzini, M; Nesti, A; Panetta, D; Fierabracci, V; Marchetti, S; Parchi, P D; Caponi, L; Paolicchi, A; Musetti, V; Salvadori, P; Edmin, M; Pucci, A; Bonicoli, E; Scaglione, M; Piolanti, N

Gamma-glutamyltransferase (GGT) has been recently identified as a bone-resorbing factor. The aim of this study was to investigate the association between plasma GGT fractions levels and bone quality. Plasma GGT fractions were analysed by gel-filtration chromatography. Bone quality was established quantitatively by two micro-CT derived microarchitectural parameters: the BV/TV (mineralised bone volume/total volume), and the SMI (structure model index) that describes the rod-like (low resistant) or plate-like (high-resistant) shape of bone trabeculae. We enrolled 93 patients hospitalised for elective total hip replacement (group Arthrosis, n=46) or for proximal femoral fracture (group Fracture, n=47). Patients within the first quartile of BV/TV (Q1, osteoporotic patients, n=6) showed higher levels of b-GGT fraction [median (min-max): 3.37 (1.42–6.81)] compared to patients with normal bone density (fourth quartile Q4, n=10; 1.40 (0.83–4.36); p=0.0393]. Also, according to SMI, b-GGT value was higher in the subgroup with bone fragility [Q1, n=8: 1.36 (0.43–4.36); Q4, n=8: 5.10 (1.4 –7.60); p=0.0117]. In conclusion, patients characterised by fragile bone structure showed specifically higher levels of plasma b-GGT activity thus suggesting fractional GGT analysis as a possible biomarker in the diagnosis of osteoporosis.

Development of a hip joint model for finite volume simulations.

PubMed

Cardiff, P; Karač, A; FitzPatrick, D; Ivanković, A

2014-01-01

This paper establishes a procedure for numerical analysis of a hip joint using the finite volume method. Patient-specific hip joint geometry is segmented directly from computed tomography and magnetic resonance imaging datasets and the resulting bone surfaces are processed into a form suitable for volume meshing. A high resolution continuum tetrahedral mesh has been generated, where a sandwich model approach is adopted; the bones are represented as a stiffer cortical shells surrounding more flexible cancellous cores. Cartilage is included as a uniform thickness extruded layer and the effect of layer thickness is investigated. To realistically position the bones, gait analysis has been performed giving the 3D positions of the bones for the full gait cycle. Three phases of the gait cycle are examined using a finite volume based custom structural contact solver implemented in open-source software OpenFOAM.

[Impact of thyroid diseases on bone].

PubMed

Tsourdi, E; Lademann, F; Siggelkow, H

2018-05-09

Thyroid hormones are key regulators of skeletal development in childhood and bone homeostasis in adulthood, and thyroid diseases have been associated with increased osteoporotic fractures. Hypothyroidism in children leads to an impaired skeletal maturation and mineralization, but an adequate and timely substitution with thyroid hormones stimulates bone growth. Conversely, hyperthyroidism at a young age accelerates skeletal development, but may also cause short stature because of a premature fusion of the growth plates. Hypothyroidism in adults causes an increase in the duration of the remodeling cycle and, thus, leads to low bone turnover and enhanced mineralization, but an association with a higher fracture risk is less well established. In adults, a surplus of thyroid hormones enhances bone turnover, mostly due to an increased bone resorption driven by osteoclasts. Thus, hyperthyroidism is a well-recognized cause of high-bone turnover secondary osteoporosis, resulting in an increased susceptibility to fragility fractures. Subclinical hyperthyroidism, especially resulting from endogenous disease, also has an adverse effect on bone mineral density and is associated with fractures. In most patients with overt or subclinical hyperthyroidism restoration of the euthyroid status reverses bone loss. In postmenopausal women who receive thyroid-stimulating hormone suppression therapy because of thyroid cancer, antiresorptive treatments may be indicated. Overall, extensive data support the importance of a euthyroid status for bone mineral accrual and growth in childhood as well as maintenance of bone health in adulthood.

Cell Mechanisms of Bone Tissue Loss Under Space Flight Conditions

NASA Astrophysics Data System (ADS)

Rodionova, Natalia

Investigations on the space biosatellites has shown that the bone skeleton is one of the most im-portant targets of the effect space flight factors on the organism. Bone tissue cells were studied by electron microscopy in biosamples of rats' long bones flown on the board american station "SLS-2" and in experiments with modelling of microgravity ("tail suspension" method) with using autoradiography. The analysis of data permits to suppose that the processes of remod-eling in bone tissue at microgravity include the following succession of cell-to-cell interactions. Osteocytes as mechanosensory cells are first who respond to a changing "mechanical field". The next stage is intensification of osteolytic processes in osteocytes, leading to a volume en-largement of the osteocytic lacunae and removal of the "excess bone". Then mechanical signals have been transmitted through a system of canals and processes of the osteocytic syncitium to certain superficial bone zones and are perceived by osteoblasts and bone-lining cells (superficial osteocytes), as well as by the bone-marrow stromal cells. The sensitivity of stromal cells, pre-osteoblasts and osteoblasts, under microgravity was shown in a number of works. As a response to microgravity, the system of stromal cells -preosteoblasts -osteoblasts displays retardation of proliferation, differentiation and specific functions of osteogenetic cells. This is supported by the 3H-thymidine studies of the dynamics of differentiation of osteogenetic cells in remodeling zones. But unloading is not adequate and in part of the osteocytes are apoptotic changes as shown by our electron microscopic investigations. An osteocytic apoptosis can play the role in attraction the osteoclasts and in regulation of bone remodeling. The apoptotic bodies with a liquid flow through a system of canals are transferred to the bone surface, where they fulfil the role of haemoattractants for monocytes come here and form osteoclasts. The osteoclasts destroy

The influence of vegan diet on bone mineral density and biochemical bone turnover markers.

PubMed

Ambroszkiewicz, Jadwiga; Klemarczyk, Witold; Gajewska, Joanna; Chełchowska, Magdalena; Franek, Edward; Laskowska-Klita, Teresa

2010-01-01

Vegetarian diets can be healthy when they are well balanced and if a variety of foods is consumed. However, elimination of animal products from the diet (vegan diets) decreases the intake of some essential nutrients and may influence the bone metabolism. This is especially important in childhood and adolescence, when growth and bone turnover are most intensive. The aim of the study was to assess the effect of vegan diet on bone density (BMD) density and serum concentrations of bone metabolism markers. We examined a family on vegan diet which consisted of parents and two children. Dietary constituents were analysed using a nutritional program. Total and regional BMD were measured by dual-energy X-ray absorptiometry. Concentrations of calcium and phosphate in serum obtained from fasting patients were determined by colorimetric methods, 25-hydroxyvitamin D by the chemiluminescence method and bone turnover markers by specific enzyme immunoassays. In studied vegans, the dietary intake of phosphate was adequate while calcium and vitamin D were below the recommended range. Concentrations of calcium, phosphate and bone turnover markers in the serum of all subjects were within the physiological range, but 25-hydroxyvitamin D level was low. Age-matched Z-score total BMD was between -0.6 and 0.3 in adults, however in children it was lower (-0.9 and -1.0). Z-score BMD lumbar spine (L2-L4) was between -0.9 to -1.9 in parents and -1.5 to -1.7 in children. Our results suggest that an inadequate dietary intake of calcium and vitamin D may impair the bone turnover rate and cause a decrease in bone mineral density in vegans. The parameters of bone density and bone metabolism should be monitored in vegans, especially children, in order to prevent bone abnormalities.

Guided bone augmentation using ceramic space-maintaining devices: the impact of chemistry

PubMed Central

Anderud, Jonas; Abrahamsson, Peter; Jimbo, Ryo; Isaksson, Sten; Adolfsson, Erik; Malmström, Johan; Naito, Yoshihito; Wennerberg, Ann

2015-01-01

The purpose of the study was to evaluate histologically, whether vertical bone augmentation can be achieved using a hollow ceramic space maintaining device in a rabbit calvaria model. Furthermore, the chemistry of microporous hydroxyapatite and zirconia were tested to determine which of these two ceramics are most suitable for guided bone generation. 24 hollow domes in two different ceramic materials were placed subperiosteal on rabbit skull bone. The rabbits were sacrificed after 12 weeks and the histology results were analyzed regarding bone-to-material contact and volume of newly formed bone. The results suggest that the effect of the microporous structure of hydroxyapatite seems to facilitate for the bone cells to adhere to the material and that zirconia enhance a slightly larger volume of newly formed bone. In conclusion, the results of the current study demonstrated that ceramic space maintaining devices permits new bone formation and osteoconduction within the dome. PMID:25792855

Finite element analysis of functionally graded bone plate at femur bone fracture site

NASA Astrophysics Data System (ADS)

Satapathy, Pravat Kumar; Sahoo, Bamadev; Panda, L. N.; Das, S.

2018-03-01

This paper focuses on the analysis of fractured Femur bone with functionally graded bone plate. The Femur bone is modeled by using the data from the CT (Computerized Tomography) scan and the material properties are assigned using Mimics software. The fracture fixation plate used here is composed of Functionally Graded Material (FGM). The functionally graded bone plate is considered to be composed of different layers of homogeneous materials. Finite element method approach is adopted for analysis. The volume fraction of the material is calculated by considering its variation along the thickness direction (z) according to a power law and the effective properties of the homogeneous layers are estimated. The model developed is validated by comparing numerical results available in the literature. Static analysis has been performed for the bone plate system by considering both axial compressive load and torsional load. The investigation shows that by introducing FG bone plate instead of titanium, the stress at the fracture site increases by 63 percentage and the deformation decreases by 15 percentage, especially when torsional load is taken into consideration. The present model yields better results in comparison with the commercially available bone plates.

Vegetarian diets and bone status.

PubMed

Tucker, Katherine L

2014-07-01

Osteoporosis is a common chronic condition associated with progressive loss of bone mineral density (BMD) and compromised bone strength, with increasing risk of fracture over time. Vegetarian diets have been shown to contain lower amounts of calcium, vitamin D, vitamin B-12, protein, and n-3 (ω-3) fatty acids, all of which have important roles in maintaining bone health. Although zinc intakes are not necessarily lower quantitatively, they are considerably less bioavailable in vegetarian diets, which suggests the need for even higher intakes to maintain adequate status. At the same time, healthy vegetarian diets tend to contain more of several protective nutrients, including magnesium, potassium, vitamin K, and antioxidant and anti-inflammatory phytonutrients. On balance, there is evidence that vegetarians, and particularly vegans, may be at greater risk of lower BMD and fracture. Attention to potential shortfall nutrients through the careful selection of foods or fortified foods or the use of supplements can help ensure healthy bone status to reduce fracture risk in individuals who adhere to vegetarian diets. © 2014 American Society for Nutrition.

Resection followed by vascularized bone autograft in patients with possible recurrence of malignant bone tumors after conservative treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Metaizeau, J.P.; Olive, D.; Bey, P.

1984-04-01

In conservative treatment of malignant bone tumors, assessment of the local condition is difficult. The radiological changes seen in the irradiated tumor and the frequent occurrence of pathological fractures at this site may give rise to the fear that the tumor has relapsed. Resection of the whole of the involved bone is the best way to assure adequate local control but the extent of the bone defect and the bad local conditions secondary to irradiation make reconstruction hazardous. In two patients (one with Ewing's sarcoma of the femur and one with osteogenic sarcoma of the humerus) the authors used amore » free, vascularized fibular graft for the reconstruction having obtained consolidation of the limb after resection of the irradiated tumor, with preservation of its function. The encouraging results obtained have suggested a conservative attitude as primary treatment of specific malignant bone tumors.« less

Bone volume fraction and structural parameters for estimation of mechanical stiffness and failure load of human cancellous bone samples; in-vitro comparison of ultrasound transit time spectroscopy and X-ray μCT.

PubMed

Alomari, Ali Hamed; Wille, Marie-Luise; Langton, Christian M

2018-02-01

Conventional mechanical testing is the 'gold standard' for assessing the stiffness (N mm -1 ) and strength (MPa) of bone, although it is not applicable in-vivo since it is inherently invasive and destructive. The mechanical integrity of a bone is determined by its quantity and quality; being related primarily to bone density and structure respectively. Several non-destructive, non-invasive, in-vivo techniques have been developed and clinically implemented to estimate bone density, both areal (dual-energy X-ray absorptiometry (DXA)) and volumetric (quantitative computed tomography (QCT)). Quantitative ultrasound (QUS) parameters of velocity and attenuation are dependent upon both bone quantity and bone quality, although it has not been possible to date to transpose one particular QUS parameter into separate estimates of quantity and quality. It has recently been shown that ultrasound transit time spectroscopy (UTTS) may provide an accurate estimate of bone density and hence quantity. We hypothesised that UTTS also has the potential to provide an estimate of bone structure and hence quality. In this in-vitro study, 16 human femoral bone samples were tested utilising three techniques; UTTS, micro computed tomography (μCT), and mechanical testing. UTTS was utilised to estimate bone volume fraction (BV/TV) and two novel structural parameters, inter-quartile range of the derived transit time (UTTS-IQR) and the transit time of maximum proportion of sonic-rays (TTMP). μCT was utilised to derive BV/TV along with several bone structure parameters. A destructive mechanical test was utilised to measure the stiffness and strength (failure load) of the bone samples. BV/TV was calculated from the derived transit time spectrum (TTS); the correlation coefficient (R 2 ) with μCT-BV/TV was 0.885. For predicting mechanical stiffness and strength, BV/TV derived by both μCT and UTTS provided the strongest correlation with mechanical stiffness (R 2 =0.567 and 0.618 respectively) and

The Efficacy of Cyclic Injection of Bone Morphogenetic Protein-2 in Large-Scale Calvarial Bone Defects.

PubMed

Choi, Jin Mi; Jeong, Woo Shik; Park, Eun Jung; Choi, Jong Woo

2017-03-01

Bone morphogenetic protein-2 (BMP-2) appears to be one of the most potent growth factors thus far studied. However, recent publications on the clinical application of BMP-2 revealed that its correct control is the paramount issue in clinical practice. For improving BMP-2 delivery, the cyclic administration might be an alternative. Accordingly, the authors cyclically injected BMP-2 in a cyclic injection model of large cranial defects to maintain the proper dosage during the bone healing process. A 10-mm diameter calvarial bone defect was produced using a round drill in 8-week-old Sprague-Dawley rats. Silk-hydroxyapatite scaffolds soaked in the appropriate concentration of BMP-2 were implanted into the defect. The animals were split into 4 single-injection groups and 3 multiple-injection groups; the latter groups received weekly subcutaneous injections of BMP-2 solution (1, 5, and 10 μg/mL) for 4 weeks, whereas the former groups received a single injection of BMP-2 at these concentrations. Each rat underwent computed tomography at 8 weeks. In terms of total volumes of the new bone, the 5 μg/mL multiple-injection BMP-2 group had significantly greater increases in bone volume than the single-injection groups. In terms of bone thickness, the multiple-injection groups had better outcomes than the single-injection groups. Thus, the cyclic injection protocol restored the original thickness without overgrowth. Cyclic injection of BMP-2 permits more accurate dosage control than single injection and improves thickness and dense bone regeneration. Therefore, it may represent a promising approach for future clinical trials. Further investigation using a greater number of animals is required.

Drilling of bone: A comprehensive review

PubMed Central

Pandey, Rupesh Kumar; Panda, S.S.

2013-01-01

Background Bone fracture treatment usually involves restoring of the fractured parts to their initial position and immobilizing them until the healing takes place. Drilling of bone is common to produce hole for screw insertion to fix the fractured parts for immobilization. Orthopaedic drilling during surgical process causes increase in the bone temperature and forces which can cause osteonecrosis reducing the stability and strength of the fixation. Methods A comprehensive review of all the relevant investigations carried on bone drilling is conducted. The experimental method used, results obtained and the conclusions made by the various researchers are described and compared. Result Review suggests that the further improvement in the area of bone drilling is possible. The systematic review identified several consequential factors (drilling parameters and drill specifications) affecting bone drilling on which there no general agreement among investigators or are not adequately evaluated. These factors are highlighted and use of more advanced methods of drilling is accentuated. The use of more precise experimental set up which resembles the actual situation and the development of automated bone drilling system to minimize human error is addressed. Conclusion In this review, an attempt has been made to systematically organize the research investigations conducted on bone drilling. Methods of treatment of bone fracture, studies on the determination of the threshold for thermal osteonecrosis, studies on the parameters influencing bone drilling and methods of the temperature measurement used are reviewed and the future work for the further improvement of bone drilling process is highlighted. PMID:26403771

Does Discontinuing Teriparatide Treatment and Replacing It with Bisphosphonate Maintain the Volume of the Bone Fusion Mass after Lumbar Posterolateral Fusion in Women with Postmenopausal Osteoporosis?

PubMed

Ohtori, Seiji; Orita, Sumihisa; Yamauchi, Kazuyo; Eguchi, Yawara; Aoki, Yasuchika; Nakamura, Junichi; Suzuki, Miyako; Kubota, Gou; Inage, Kazuhide; Shiga, Yasuhiro; Abe, Koki; Fujimoto, Kazuki; Kanamoto, Hirohito; Inoue, Masahiro; Kinoshita, Hideyuki; Furuya, Takeo; Koda, Masao

2017-04-01

Retrospective case series. The purpose of this study was to determine whether discontinuing teriparatide treatment and replacing it with bisphosphonate treatment maintains the volume of the fusion mass after posterolateral fusion (PLF) in women with postmenopausal osteoporosis. Clinical data support the efficacy of parathyroid hormone (PTH) for lumbar PLF. However, the use of PTH is limited to 2 years. We treated 19 women diagnosed with osteoporosis and degenerative spondylolisthesis with teriparatide (20 µg daily subcutaneously). All patients underwent one-level instrumented PLF. Teriparatide was used during 2 months prior to surgery and more than 8 months after surgery. After discontinuing teriparatide treatment, all patients used bisphosphonate (17.5 mg risedronate weekly, oral administration). Area of the fusion mass across the transverse processes at one segment was determined on an anteroposterior radiograph at 1, 2, and 3 years after surgery. We followed 19 patients for 3 years. The average duration of teriparatide treatment was 11.5 months. The bone union rate was 95%. The average area of the bone fusion mass was not significantly different between the right and left sides at 1, 2, or 3 years after surgery ( p >0.05). This study showed that replacing teriparatide treatment with bisphosphonate maintained the bone fusion mass volume after PLF in women with postmenopausal osteoporosis.

7 CFR 3017.900 - Adequate evidence.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false Adequate evidence. 3017.900 Section 3017.900 Agriculture Regulations of the Department of Agriculture (Continued) OFFICE OF THE CHIEF FINANCIAL OFFICER... Adequate evidence. Adequate evidence means information sufficient to support the reasonable belief that a...

In vivo microcomputed tomography evaluation of rat alveolar bone and root resorption during orthodontic tooth movement.

PubMed

Ru, Nan; Liu, Sean Shih-Yao; Zhuang, Li; Li, Song; Bai, Yuxing

2013-05-01

To observe the real-time microarchitecture changes of the alveolar bone and root resorption during orthodontic treatment. A 10 g force was delivered to move the maxillary left first molars mesially in twenty 10-week-old rats for 14 days. The first molar and adjacent alveolar bone were scanned using in vivo microcomputed tomography at the following time points: days 0, 3, 7, and 14. Microarchitecture parameters, including bone volume fraction, structure model index, trabecular thickness, trabecular number, and trabecular separation of alveolar bone, were measured on the compression and tension side. The total root volume was measured, and the resorption crater volume at each time point was calculated. Univariate repeated measures analysis of variance with Bonferroni corrections were performed to compare the differences in each parameter between time points with significance level at P < .05. From day 3 to day 7, bone volume fraction, structure model index, trabecular thickness, and trabecular separation decreased significantly on the compression side, but the same parameters increased significantly on the tension side from day 7 to day 14. Root resorption volume of the mesial root increased significantly on day 7 of orthodontic loading. Real-time root and bone resorption during orthodontic movement can be observed in 3 dimensions using in vivo micro-CT. Alveolar bone resorption and root resorption were observed mostly in the apical third on day 7 on the compression side; bone formation was observed on day 14 on the tension side during orthodontic tooth movement.

29 CFR 98.900 - Adequate evidence.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 29 Labor 1 2012-07-01 2012-07-01 false Adequate evidence. 98.900 Section 98.900 Labor Office of the Secretary of Labor GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 98.900 Adequate evidence. Adequate evidence means information sufficient to support the reasonable belief that a...

29 CFR 98.900 - Adequate evidence.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 1 2011-07-01 2011-07-01 false Adequate evidence. 98.900 Section 98.900 Labor Office of the Secretary of Labor GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 98.900 Adequate evidence. Adequate evidence means information sufficient to support the reasonable belief that a...

29 CFR 98.900 - Adequate evidence.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 1 2013-07-01 2013-07-01 false Adequate evidence. 98.900 Section 98.900 Labor Office of the Secretary of Labor GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 98.900 Adequate evidence. Adequate evidence means information sufficient to support the reasonable belief that a...

Improved osseointegration with as-built electron beam melted textured implants and improved peri‑implant bone volume with whole body vibration.

PubMed

Ruppert, David S; Harrysson, Ola L A; Marcellin-Little, Denis J; Dahners, Laurence E; Weinhold, Paul S

2018-06-11

Transcutaneous osseointegrated prostheses provide stable connections to the skeleton while eliminating skin lesions experienced with socket prosthetics. Additive manufacturing can create custom textured implants capable of interfacing with amputees' residual bones. Our objective was to compare osseointegration of textured surface implants made by electron beam melting (EBM), an additive manufacturing process, to machine threaded implants. Whole body vibration was investigated to accelerate osseointegration. Two cohorts of Sprague-Dawley rats received bilateral, titanium implants (EBM vs. threaded) in their tibiae. One cohort comprising five groups vibrated at 45 Hz: 0.0 (control), 0.15, 0.3, 0.6 or 1.2 g was followed for six weeks. Osseointegration was evaluated through torsional testing and bone volume fraction (BV/TV). A second cohort, divided into two groups (control and 0.6 g), was followed for 24 days and evaluated for resonant frequency, bone-implant contact (BIC) and fluorochrome labeling. The EBM textured implants exhibited significantly improved mechanical stability independent of vibration, highlighting the benefits of using EBM to produce custom textured surfaces. Bone formation on and around the EBM textured implants increased compared to machined implants, as seen by BIC and fluorescence. No difference in torque, BIC or fluorescence among vibration levels was detected. BV/TV significantly increased at 0.6 g compared to control for both implant types. Copyright © 2018 IPEM. Published by Elsevier Ltd. All rights reserved.

Combined micro computed tomography and histology study of bone augmentation and distraction osteogenesis

NASA Astrophysics Data System (ADS)

Ilgenstein, Bernd; Deyhle, Hans; Jaquiery, Claude; Kunz, Christoph; Stalder, Anja; Stübinger, Stefan; Jundt, Gernot; Beckmann, Felix; Müller, Bert; Hieber, Simone E.

2012-10-01

Bone augmentation is a vital part of surgical interventions of the oral and maxillofacial area including dental implantology. Prior to implant placement, sufficient bone volume is needed to reduce the risk of peri-implantitis. While augmentation using harvested autologous bone is still considered as gold standard, many surgeons prefer bone substitutes to reduce operation time and to avoid donor site morbidity. To assess the osteogenic efficacy of commercially available augmentation materials we analyzed drill cores extracted before implant insertion. In younger patients, distraction osteogenesis is successfully applied to correct craniofacial deformities through targeted bone formation. To study the influence of mesenchymal stem cells on bone regeneration during distraction osteogenesis, human mesenchymal stem cells were injected into the distraction gap of nude rat mandibles immediately after osteotomy. The distraction was performed over eleven days to reach a distraction gap of 6 mm. Both the rat mandibles and the drill cores were scanned using synchrotron radiation-based micro computed tomography. The three-dimensional data were manually registered and compared with corresponding two-dimensional histological sections to assess bone regeneration and its morphology. The analysis of the rat mandibles indicates that bone formation is enhanced by mesenchymal stem cells injected before distraction. The bone substitutes yielded a wide range of bone volume and degree of resorption. The volume fraction of the newly formed bone was determined to 34.4% in the computed tomography dataset for the augmentation material Geistlich Bio-Oss®. The combination of computed tomography and histology allowed a complementary assessment for both bone augmentation and distraction osteogenesis.

Cervical vertebral bone mineral density changes in adolescents during orthodontic treatment.

PubMed

Crawford, Bethany; Kim, Do-Gyoon; Moon, Eun-Sang; Johnson, Elizabeth; Fields, Henry W; Palomo, J Martin; Johnston, William M

2014-08-01

The cervical vertebral maturation (CVM) stages have been used to estimate facial growth status. In this study, we examined whether cone-beam computed tomography images can be used to detect changes of CVM-related parameters and bone mineral density distribution in adolescents during orthodontic treatment. Eighty-two cone-beam computed tomography images were obtained from 41 patients before (14.47 ± 1.42 years) and after (16.15 ± 1.38 years) orthodontic treatment. Two cervical vertebral bodies (C2 and C3) were digitally isolated from each image, and their volumes, means, and standard deviations of gray-level histograms were measured. The CVM stages and mandibular lengths were also estimated after converting the cone-beam computed tomography images. Significant changes for the examined variables were detected during the observation period (P ≤0.018) except for C3 vertebral body volume (P = 0.210). The changes of CVM stage had significant positive correlations with those of vertebral body volume (P ≤0.021). The change of the standard deviation of bone mineral density (variability) showed significant correlations with those of vertebral body volume and mandibular length for C2 (P ≤0.029). The means and variability of the gray levels account for bone mineral density and active remodeling, respectively. Our results indicate that bone mineral density distribution and the volume of the cervical vertebral body changed because of active bone remodeling during maturation. Copyright © 2014 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Clinical utility of bone turnover markers in the management of common metabolic bone diseases in adults.

PubMed

Glendenning, Paul; Chubb, S A Paul; Vasikaran, Samuel

2018-06-01

Bone turnover marker (BTMs) concentrations in blood and urine reflect bone-remodelling activity, and may be useful adjuncts in the diagnosis and management of metabolic bone diseases. Newer biomarkers, mainly bone regulatory proteins, are currently being investigated to elucidate their role in bone metabolism and disease and may in future be useful in clinical diagnosis and management of metabolic bone disease. BTM concentrations increase around menopause in women, and at a population level the degree of increase in BTMs reflect bone loss. However, lack of adequate data precludes their use in individual patients for fracture risk assessment in clinical practice. The rapid and large changes in BTMs following anti-resorptive and anabolic therapies for osteoporosis treatment indicate they may be useful for monitoring therapy in clinical practice. The offset of drug effect on BTMs could be helpful for adjudicating the duration of bisphosphonate drug holidays. BTMs may offer useful additional data in skeletal diseases that are typically characterised by increased bone remodelling: chronic kidney disease (CKD), primary hyperparathyroidism (PHPT) and Paget's disease. In CKD, bone specific alkaline phosphatase (bAP) is currently endorsed for use for the assessment of mineral bone disease. The role of BTMsin predicting the bone mineral density response to successful parathyroidectomy in PHPT shows some utility but the data are not consistent and studies are limited in size and/or duration. In Paget's disease of bone, BTMs are used to confirm diagnosis, evaluate extent of disease or degree of activity and for monitoring the response to bisphosphonate treatment. Whilst BTMs are currently used in specific clinical practice instances when investigating or managing metabolic bone disease, further data are needed to consolidate their clinical use where evidence of utility is limited. Copyright © 2018 Elsevier B.V. All rights reserved.

2 CFR 180.900 - Adequate evidence.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 2 Grants and Agreements 1 2013-01-01 2013-01-01 false Adequate evidence. 180.900 Section 180.900 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements OFFICE OF... Adequate evidence. Adequate evidence means information sufficient to support the reasonable belief that a...

2 CFR 180.900 - Adequate evidence.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 2 Grants and Agreements 1 2012-01-01 2012-01-01 false Adequate evidence. 180.900 Section 180.900 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements OFFICE OF... Adequate evidence. Adequate evidence means information sufficient to support the reasonable belief that a...

Moderate chronic kidney disease impairs bone quality in C57Bl/6J mice.

PubMed

Heveran, Chelsea M; Ortega, Alicia M; Cureton, Andrew; Clark, Ryan; Livingston, Eric W; Bateman, Ted A; Levi, Moshe; King, Karen B; Ferguson, Virginia L

2016-05-01

Chronic kidney disease (CKD) increases bone fracture risk. While the causes of bone fragility in CKD are not clear, the disrupted mineral homeostasis inherent to CKD may cause material quality changes to bone tissue. In this study, 11-week-old male C57Bl/6J mice underwent either 5/6th nephrectomy (5/6 Nx) or sham surgeries. Mice were fed a normal chow diet and euthanized 11weeks post-surgery. Moderate CKD with high bone turnover was established in the 5/6 Nx group as determined through serum chemistry and bone gene expression assays. We compared nanoindentation modulus and mineral volume fraction (assessed through quantitative backscattered scanning electron microscopy) at matched sites in arrays placed on the cortical bone of the tibia mid-diaphysis. Trabecular and cortical bone microarchitecture and whole bone strength were also evaluated. We found that moderate CKD minimally affected bone microarchitecture and did not influence whole bone strength. Meanwhile, bone material quality decreased with CKD; a pattern of altered tissue maturation was observed with 5/6 Nx whereby the newest 60μm of bone tissue adjacent to the periosteal surface had lower indentation modulus and mineral volume fraction than more interior, older bone. The variance of modulus and mineral volume fraction was also altered following 5/6 Nx, implying that tissue-scale heterogeneity may be negatively affected by CKD. The observed lower bone material quality may play a role in the decreased fracture resistance that is clinically associated with human CKD. Copyright © 2016 Elsevier Inc. All rights reserved.

Moderate Chronic Kidney Disease Impairs Bone Quality in C57Bl/6J Mice

PubMed Central

Heveran, Chelsea M.; Ortega, Alicia M.; Cureton, Andrew; Clark, Ryan; Livingston, Eric; Bateman, Ted; Levi, Moshe; King, Karen B.; Ferguson, Virginia L.

2016-01-01

Chronic kidney disease (CKD) increases bone fracture risk. While the causes of bone fragility in CKD are not clear, the disrupted mineral homeostasis inherent to CKD may cause material quality changes to bone tissue. In this study, 11-week old male C57Bl/6J mice underwent either 5/6th nephrectomy (5/6 Nx) or sham procedures. Mice were fed a normal chow diet and euthanized 11 weeks post-surgery. Moderate CKD with high bone turnover was established in the 5/6 Nx group as determined through serum chemistry and bone gene expression assays. We compared nanoindentation modulus and mineral volume fraction (assessed through quantitative backscattered scanning electron microscopy) at matched sites in arrays placed on the cortical bone of the tibia mid-diaphysis. Trabecular and cortical bone microarchitecture (μCT) and whole bone strength were also evaluated. We found that moderate CKD minimally affected bone microarchitecture and did not influence whole bone strength. Meanwhile, bone material quality decreased with CKD; a pattern of altered tissue maturation was observed with 5/6 Nx whereby the newest 60 micrometers of bone tissue adjacent to the periosteal surface had lower indentation modulus and mineral volume fraction than more interior, older bone. The variance of modulus and mineral volume fraction were also altered following 5/6 Nx, implying that tissue-scale heterogeneity may be negatively affected by CKD. The observed lower bone material quality may play a role in the decreased fracture resistance that is clinically associated with human CKD. PMID:26860048

Bone and muscle atrophy with suspension of the rat

NASA Technical Reports Server (NTRS)

Leblanc, A.; Marsh, C.; Evans, H.; Johnson, P.; Schneider, V.; Jhingran, S.

1985-01-01

In order to identify a suitable model for the study of muscle atrophy due to suspension in space, a modified version of the Morey tail suspension model was used to measure the atrophic responses of rat bone and muscle to 14-30 days of unloading of the hindlimbs. The progress of atrophy was measured by increases in methylene diphosphonate (MDP) uptake. It is found that bone uptake of methylene diphosphonate followed a phasic pattern similar to changes in the bone formation rate of immobilized dogs and cats. Increased MDP uptake after a period of 60 days indicated an accelerated bone metabolism. Maximum muscle atrophy in the suspended rats was distinctly different from immobilization atrophy. On the basis of the experimental results, it is concluded that the tail suspension model is an adequate simulation of bone atrophy due to suspension.

High doses of bone morphogenetic protein 2 induce structurally abnormal bone and inflammation in vivo.

PubMed

Zara, Janette N; Siu, Ronald K; Zhang, Xinli; Shen, Jia; Ngo, Richard; Lee, Min; Li, Weiming; Chiang, Michael; Chung, Jonguk; Kwak, Jinny; Wu, Benjamin M; Ting, Kang; Soo, Chia

2011-05-01

The major Food and Drug Association-approved osteoinductive factors in wide clinical use are bone morphogenetic proteins (BMPs). Although BMPs can promote robust bone formation, they also induce adverse clinical effects, including cyst-like bone formation and significant soft tissue swelling. In this study, we evaluated multiple BMP2 doses in a rat femoral segmental defect model and in a minimally traumatic rat femoral onlay model to determine its dose-dependent effects. Results of our femoral segmental defect model established a low BMP2 concentration range (5 and 10 μg/mL, total dose 0.375 and 0.75 μg in 75 μg total volume) unable to induce defect fusion, a mid-range BMP2 concentration range able to fuse the defect without adverse effects (30 μg/mL, total dose 2.25 μg in 75 μg total volume), and a high BMP2 concentration range (150, 300, and 600 μg/mL, total dose 11.25, 22.5, and 45 μg in 75 μg total volume) able to fuse the defect, but with formation of cyst-like bony shells filled with histologically confirmed adipose tissue. In addition, compared to control, 4 mg/mL BMP2 also induced significant tissue inflammatory infiltrates and exudates in the femoral onlay model that was accompanied by increased numbers of osteoclast-like cells at 3, 7, and 14 days. Overall, we consistently reproduced BMP2 side effects of cyst-like bone and soft tissue swelling using high BMP2 concentration approaching the typical human 1500 μg/mL.

High Doses of Bone Morphogenetic Protein 2 Induce Structurally Abnormal Bone and Inflammation In Vivo

PubMed Central

Zara, Janette N.; Siu, Ronald K.; Zhang, Xinli; Shen, Jia; Ngo, Richard; Lee, Min; Li, Weiming; Chiang, Michael; Chung, Jonguk; Kwak, Jinny; Wu, Benjamin M.; Ting, Kang

2011-01-01

The major Food and Drug Association–approved osteoinductive factors in wide clinical use are bone morphogenetic proteins (BMPs). Although BMPs can promote robust bone formation, they also induce adverse clinical effects, including cyst-like bone formation and significant soft tissue swelling. In this study, we evaluated multiple BMP2 doses in a rat femoral segmental defect model and in a minimally traumatic rat femoral onlay model to determine its dose-dependent effects. Results of our femoral segmental defect model established a low BMP2 concentration range (5 and 10 μg/mL, total dose 0.375 and 0.75 μg in 75 μg total volume) unable to induce defect fusion, a mid-range BMP2 concentration range able to fuse the defect without adverse effects (30 μg/mL, total dose 2.25 μg in 75 μg total volume), and a high BMP2 concentration range (150, 300, and 600 μg/mL, total dose 11.25, 22.5, and 45 μg in 75 μg total volume) able to fuse the defect, but with formation of cyst-like bony shells filled with histologically confirmed adipose tissue. In addition, compared to control, 4 mg/mL BMP2 also induced significant tissue inflammatory infiltrates and exudates in the femoral onlay model that was accompanied by increased numbers of osteoclast-like cells at 3, 7, and 14 days. Overall, we consistently reproduced BMP2 side effects of cyst-like bone and soft tissue swelling using high BMP2 concentration approaching the typical human 1500 μg/mL. PMID:21247344

Combined treatment with a transforming growth factor beta inhibitor (1D11) and bortezomib improves bone architecture in a mouse model of myeloma-induced bone disease

PubMed Central

Nyman, Jeffry S.; Merkel, Alyssa R.; Uppuganti, Sasidhar; Nayak, Bijaya; Rowland, Barbara; Makowski, Alexander J.; Oyajobi, Babatunde O.; Sterling, Julie A.

2016-01-01

Multiplemyeloma (MM) patients frequently develop tumor-induced bone destruction, yet no therapy completely eliminates the tumor or fully reverses bone loss. Transforming growth factor-β (TGF-β) activity often contributes to tumor-induced bone disease, and pre-clinical studies have indicated that TGF-β inhibition improves bone volume and reduces tumor growth in bone metastatic breast cancer. We hypothesized that inhibition of TGF-β signaling also reduces tumor growth, increases bone volume, and improves vertebral body strength in MM-bearing mice. We treated myeloma tumor-bearing (immunocompetent KaLwRij and immunocompromised Rag2 −/−) mice with a TGF-β inhibitory (1D11) or control (13C4) antibody, with or without the anti-myeloma drug bortezomib, for 4 weeks after inoculation of murine 5TGM1 MM cells. TGF-β inhibition increased trabecular bone volume, improved trabecular architecture, increased tissue mineral density of the trabeculae as assessed by ex vivo micro-computed tomography, and was associated with significantly greater vertebral body strength in biomechanical compression tests. Serum monoclonal paraprotein titers and spleen weights showed that 1D11 monotherapy did not reduce overall MM tumor burden. Combination therapy with 1D11 and bortezomib increased vertebral body strength, reduced tumor burden, and reduced cortical lesions in the femoral metaphysis, although it did not significantly improve cortical bone strength in three-point bending tests of the mid-shaft femur. Overall, our data provides rationale for evaluating inhibition of TGF-β signaling in combination with existing anti-myeloma agents as a potential therapeutic strategy to improve outcomes in patients with myeloma bone disease. PMID:27423464

Combined treatment with a transforming growth factor beta inhibitor (1D11) and bortezomib improves bone architecture in a mouse model of myeloma-induced bone disease.

PubMed

Nyman, Jeffry S; Merkel, Alyssa R; Uppuganti, Sasidhar; Nayak, Bijaya; Rowland, Barbara; Makowski, Alexander J; Oyajobi, Babatunde O; Sterling, Julie A

2016-10-01

Multiple myeloma (MM) patients frequently develop tumor-induced bone destruction, yet no therapy completely eliminates the tumor or fully reverses bone loss. Transforming growth factor-β (TGF-β) activity often contributes to tumor-induced bone disease, and pre-clinical studies have indicated that TGF-β inhibition improves bone volume and reduces tumor growth in bone metastatic breast cancer. We hypothesized that inhibition of TGF-β signaling also reduces tumor growth, increases bone volume, and improves vertebral body strength in MM-bearing mice. We treated myeloma tumor-bearing (immunocompetent KaLwRij and immunocompromised Rag2-/-) mice with a TGF-β inhibitory (1D11) or control (13C4) antibody, with or without the anti-myeloma drug bortezomib, for 4weeks after inoculation of murine 5TGM1 MM cells. TGF-β inhibition increased trabecular bone volume, improved trabecular architecture, increased tissue mineral density of the trabeculae as assessed by ex vivo micro-computed tomography, and was associated with significantly greater vertebral body strength in biomechanical compression tests. Serum monoclonal paraprotein titers and spleen weights showed that 1D11 monotherapy did not reduce overall MM tumor burden. Combination therapy with 1D11 and bortezomib increased vertebral body strength, reduced tumor burden, and reduced cortical lesions in the femoral metaphysis, although it did not significantly improve cortical bone strength in three-point bending tests of the mid-shaft femur. Overall, our data provides rationale for evaluating inhibition of TGF-β signaling in combination with existing anti-myeloma agents as a potential therapeutic strategy to improve outcomes in patients with myeloma bone disease. Published by Elsevier Inc.

Promising efficacy of Escherichia coli recombinant human bone morphogenetic protein-2 in collagen sponge for ectopic and orthotopic bone formation and comparison with mammalian cell recombinant human bone morphogenetic protein-2.

PubMed

Kim, In Sook; Lee, Eui Nam; Cho, Tae Hyung; Song, Yun Mi; Hwang, Soon Jung; Oh, Ji Hye; Park, Eun Kyung; Koo, Tai Young; Seo, Young-Kwon

2011-02-01

Nonglycosylated recombinant human bone morphogenetic protein (rhBMP)-2 prepared in Escherichia coli (E. coli rhBMP-2) has recently been considered as an alternative to mammalian cell rhBMP-2. However, its clinical use is still limited owing to lack of evidence for osteogenic activity comparable with that of mammalian cell rhBMP-2 via microcomputed tomography-based analysis. Therefore, this study aimed to evaluate the ability of E. coli rhBMP-2 in absorbable collagen sponge to form ectopic and orthotopic bone and to compare it to that of mammalian rhBMP-2. In vitro investigation was performed to study osteoblast differentiation of human mesenchymal stromal cells. Both types of rhBMP-2 enhanced proliferation, alkaline phosphatase activity, and matrix mineralization of human mesenchymal stromal cells at similar levels. Similar tendencies were observed in microcomputed tomography analysis, which determined bone volume, fractional bone volume, trabecular thickness, trabecular separation, bone mineral density, and other characteristics. Histology from an in vivo osteoinductivity test and from a rat calvarial defect model demonstrated a dose-dependent increase in local bone formation. The E. coli rhBMP-2 group (5 μg) not only induced complete regeneration of an 8-mm critical-sized defect at 4 weeks, but also led to new bone with the same bone mineral density as normal bone at 8 weeks, with the same efficiency as that of mammalian cell rhBMP-2 (5 μg). These uniformly favorable results provide evidence that the osteogenic activity of E. coli rhBMP-2 is not inferior to that of mammalian cell rhBMP-2 despite its low solubility and lack of gylcosylation. These results suggest that the application of E. coli rhBMP-2 in absorbable collagen sponge may be a promising equivalent to mammalian cell rhBMP-2 in bone tissue engineering.

Daily intermittent decreases in serum levels of parathyroid hormone have an anabolic-like action on the bones of uremic rats with low-turnover bone and osteomalacia.

PubMed

Ishii, H; Wada, M; Furuya, Y; Nagano, N; Nemeth, E F; Fox, J

2000-02-01

The calcium receptor agonist (calcimimetic) compound NPS R-568 causes rapid decreases in circulating levels of parathyroid hormone (PTH) in rats and humans. We hypothesized that daily intermittent decreases in serum PTH levels may have different effects on bone than do chronically sustained decreases. To test this hypothesis, we compared two NPS R-568 dosing regimens in rats with chronic renal insufficiency induced by two intravenous injections of adriamycin. Fourteen weeks after the second adriamycin injection, creatinine clearance was reduced by 52%, PTH levels were elevated approximately 2.5-fold, and serum 25(OH)D3 and 1,25(OH)2D3 levels were reduced substantially. Treatment by daily per os gavage, which decreased PTH levels intermittently, or continuous subcutaneous infusion, which resulted in a sustained suppression of serum PTH levels, then began for 8 weeks. Despite the hyperparathyroidism, the adriamycin-injected rats developed a low-turnover bone lesion with osteomalacia (fourfold increase in osteoid volume in the proximal tibial metaphysis) and osteopenia (67% decrease in cancellous bone volume and an 18% reduction in bone mineral density at the distal femur). Daily administered (but not infused) NPS R-568 significantly increased cancellous bone volume solely by normalizing trabecular thickness, and increased femoral bone mineral density by 14%. These results indicate that daily intermittent, but not sustained, decreases in PTH levels have an "anabolic-like" effect on bones with a low-turnover lesion in this animal model of chronic renal insufficiency.

Maintaining Restored Bone with Bisphoshonate in the Ovariectomized Rat Skeleton: Dynamic Histomorphometry of Changes in Bone Mass

NASA Technical Reports Server (NTRS)

Jee, W. S. S.; Tang, L.; Ke, H. Z.; Setterberg, R. B.; Kimmel, D. B.

1993-01-01

This experiment contains the crucial data for the Lose, Restore and Maintain (LRM) concept, a practical approach for reversing existing osteoporosis. The LRM concept uses ovariectomy (ox) to lose bone, an anabolic agent to restore bone mass and then switches to an anti-resorptive agent to maintain bone mass. We ox'd or sham-ox'd rats for 150 days (Loss Phase), treated them with 6 mg PGE2/kg/d for 75 days to restore lost cancellous bone mass (Restore Phase) and then stopped PGE2 treatment and began treatment with 1 or 5 micro-g/kg Risedronate, a bisphosphonate twice a week for 60 days (Maintain Phase). During the Loss Phase, cancellous bone volumes of the proximal tibial metaphysis (PTM) in the ox'd rat fell to 19% of initial controls. During the Restore Phase, the PTM bone volume in ox'd rats doubled. However, when PGE2 treatment was stopped, the PGE2-induced cancellous bone disappeared. In contrast, 5 micro-g of Risedronate inhibited the bone loss and maintained it at the PGE2 treatment level. The key dynamic histomorphometry value for the restore (R) and maintenance (M) phases was the ratio of bone formation to resorption rates. The ratio was elevated to 5.8 in the R phase and depressed to 0.4 for no and 1 micro-g Risedronate treated M phase and to a ratio of near unity of 1.1 for the 5 micro-g Risedronate treatment. These findings indicate that we were successful in maintaining the new PTM bone induced by PGE2 after discontinuing PGE2 by administering enough Risedronate, a resorption inhibitor. We concluded that the LRM concept is correct and such an approach should be considered when employing anabolic agents or growth factors in the treatment of osteoporosis. Continued use of an anabolic agent may not be appropriate because of cost, potential adverse side effects and a loss of efficacy.

Maintaining Restored Bone with Bisphosphonate in the Ovariectomized Rat Skeleton: Dynamic Histomorphometry of Changes in Bone Mass

NASA Technical Reports Server (NTRS)

Jee, W. S. S.; Tang, L.; Ke, H. Z.; Setterberg, R. B.; Kimmel, D. B.

1993-01-01

This experiment contains the crucial data for the Lose, Restore and Maintain (LRM) concept, a practical approach for reversing existing osteoporosis. The LRM concept uses ovariectomy (ox) to lose bone, an anabolic agent to restore bone mass and then switches to an antiresorptive agent to maintain bone mass. We ox'd or sham-ox'd rats for 150 days (Loss Phase), treated them with 6 mg PGE(sub 2)kg/d for 75 days to restore lost cancellous bone mass (Restore Phase) and then stopped PGE(sub 2) treatment and began treatment with 1 or 5 micrograms/kg Risedronate, a bisphosphonate twice a week for 60 days (Maintain Phase). During the Loss Phase, cancellous bone volumes of the Proximal Tibial Metaphysis (PTM) in the ox'd rat fell to 19% of initial controls. During the Restore Phase, the PTM bone volume in ox'd rats doubled. However, when PGE(sub 2) treatment was stopped, the PGE(sub 2)-induced cancellous bone disappeared. In contrast, 5 miligrams of Risedronate inhibited the bone loss and maintained it at the PGE(sub 2) treatment level. The key dynamic histomorphometry value for the Restore (R) and Maintenance (M) phases was the ratio of bone formation to resorption rates. The ratio was elevated to 5.8 in the R phase and depressed to 0.4 for no and 1 miligram Risedronate treated M phase and to a ratio of near unity of 1.1 for the 5miligrams Risedronate treatment. These findings indicate that we were successful in maintaining the new PTM bone induced by PGE(sub 2) after discontinuing PGE(sub 2) by administering enough Risedronate, a resorption inhibitor. We concluded that the LRM concept is correct and such an approach should be considered when employing anabolic agents or growth factors in the treatment of osteoporosis. Continued use of an anabolic agent may not be appropriate because of cost, potential adverse side effects and a loss of efficacy.

Does Guided Bone Regeneration Prevent Unfavorable Bone Shapes in Distraction Gap?

PubMed

Demetoglu, Umut; Alkan, Alper; Kiliç, Erdem; Ozturk, Mustafa; Bilge, Suheyb

2018-03-01

Complications related to distraction osteogenesis can cause degradation of newly regenerated bone. Additionally, an unfavorable shape of the regenerated bone at the distraction gap can reduce the quantity of regenerated bone. The aim of the present study was to report on the prevention of unfavorable shapes of regenerated bone using guided bone regeneration during distraction. Bilateral alveolar distraction was performed in 10 beagle dog mandibles. One side of the mandible formed the experimental group and the other side served as the control group. In the experimental group, guided bone regeneration was performed simultaneously with distraction osteogenesis. In the control group, only alveolar distraction was applied. At the end of a 1-week latent period, all mandibles were distracted 10 mm (1 mm/day). After the distraction period, 3 months were allowed for consolidation. After consolidation, all the dogs were euthanized, and the shape of the regenerated bone was determined to be either favorable or unfavorable. Densitometric evaluation and area measurements were performed using computed tomography scans. Statistical evaluation was performed using the independent t test, with a significance level of P < .05. In the experimental group, no unfavorable bone shape developed in the distraction gap, and the new bone had a surface and volume similar to those of the segments. In contrast, in the control group, 4 mandibles had an unfavorable bone shape in the distraction gap and 4 showed favorable bone healing with no defect. The surface area of the regenerating bone in the experimental group was significantly greater than that in the control group. Also, the surface area differed significantly between the experimental and control groups (P < .05). However, the densitometric values did not differ between the 2 groups (P < .05). Concomitant use of guided bone regeneration with distraction osteogenesis could be an optimal method for generating a favorable bone shape

Fast decomposition of two ultrasound longitudinal waves in cancellous bone using a phase rotation parameter for bone quality assessment: Simulation study.

PubMed

Taki, Hirofumi; Nagatani, Yoshiki; Matsukawa, Mami; Kanai, Hiroshi; Izumi, Shin-Ichi

2017-10-01

Ultrasound signals that pass through cancellous bone may be considered to consist of two longitudinal waves, which are called fast and slow waves. Accurate decomposition of these fast and slow waves is considered to be highly beneficial in determination of the characteristics of cancellous bone. In the present study, a fast decomposition method using a wave transfer function with a phase rotation parameter was applied to received signals that have passed through bovine bone specimens with various bone volume to total volume (BV/TV) ratios in a simulation study, where the elastic finite-difference time-domain method is used and the ultrasound wave propagated parallel to the bone axes. The proposed method succeeded to decompose both fast and slow waves accurately; the normalized residual intensity was less than -19.5 dB when the specimen thickness ranged from 4 to 7 mm and the BV/TV value ranged from 0.144 to 0.226. There was a strong relationship between the phase rotation value and the BV/TV value. The ratio of the peak envelope amplitude of the decomposed fast wave to that of the slow wave increased monotonically with increasing BV/TV ratio, indicating the high performance of the proposed method in estimation of the BV/TV value in cancellous bone.

Recombinant human bone morphogenetic protein-2 stimulates bone formation during interfrontal suture expansion in rabbits.

PubMed

Liu, Sean Shih-Yao; Xu, Haisong; Sun, Jun; Kontogiorgos, Elias; Whittington, Patrick R; Misner, Kenner G; Kyung, Hee-Moon; Buschang, Peter H; Opperman, Lynne A

2013-08-01

Suture expansion stimulates bone growth to correct craniofacial deficiencies but has a high potential of treatment relapse. The objective of this study was to investigate whether there is a dose-dependent relationship between the recombinant human bone morphogenetic protein-2 (rhBMP-2) and bone formation during suture expansion. Fifty 6-week-old male New Zealand white rabbits were randomly assigned to 5 groups to receive 0 (control), 0.01, 0.025, 0.1, or 0.4 mg/mL of rhBMP-2 delivered by absorbable collagen sponge placed over the interfrontal suture. The suture was expanded for 33 days by 200 g of constant force via a spring anchored with 2 miniscrew implants. Distance of suture expansion, suture volume, and cross-sectional area after expansion were measured using radiographs with bone markers and microcomputed tomography. Suture widths and mineralization appositional rates were calculated based on the widths between bone labels under an epifluorescent microscope. Software (Multilevel Win 2.0; University of Bristol, Bristol, United Kingdom) was used to model distance of suture expansion over time as polynomials to compare group differences. Wilcoxon signed rank tests were performed to compare the suture volume and cross-sectional area, mineral apposition rate, and suture width between groups. The significance level was set at P = 0.05. Whereas the sutures were expanded in all groups, sutures were expanded by significantly greater amounts in the control and the 0.01 mg/mL groups without fusing the sutures than in the 0.025, 0.1, and 0.4 mg/mL groups with fusing sutures. Compared with the controls, the 0.01 mg/mL group showed significantly lower suture volumes, cross-sectional areas, and suture widths after expansion. The mineral apposition rate was significantly higher in the 0.01 mg/mL group than in the controls from days 10 to 30. The 0.01 mg/mL dose of rhBMP-2 delivered by absorbable collagen sponge can stimulate bone formation at the bony edges of the suture

The Biomechanical Properties of Pedicle Screw Fixation Combined With Trajectory Bone Cement Augmentation in Osteoporotic Vertebrae.

PubMed

Fan, Haitao T; Zhang, Renjie J; Shen, Cailiang L; Dong, Fulong L; Li, Yong; Song, Peiwen W; Gong, Chen; Wang, Yijin J

2016-03-01

The biomechanics of pedicle screw fixation combined with trajectory cement augmentation with various filling volumes were measured by pull-out, periodic antibending, and compression fatigue tests. To investigate the biomechanical properties of the pedicle screw fixation combined with trajectory bone cement (polymethylmethacrylate) augmentation in osteoporotic vertebrae and to explore the optimum filling volume of the bone cement. Pedicle screw fixation is considered to be the most effective posterior fixation method. The decrease of the bone mineral density apparently increases the fixation failure risk caused by screw loosening and displacement. Trajectory bone cement augmentation has been confirmed to be an effective method to increase the bone intensity and could markedly increase the stability of the fixation interface. Sixteen elderly cadaveric 1-5 lumbar vertebral specimens were diagnosed with osteoporosis. The left and right vertebral pedicles were alternatively randomized for treatment in all groups, with the contralateral pedicles as control. The study groups included: group A (pedicle screw fixation with full trajectory bone cement augmentation), group B (75% filling), group C (50% filling), and group D (25% filling). Finally, the bone cement leakage and dispersion were assessed and the mechanical testing was conducted. The bone cement was well dispersed around the pedicle screw. The augmented bone intensity, pull-out strength, periodic loading times, and compression fatigue performance were markedly higher than those of the control groups. With the increase in trajectory bone cement, the leakage was also increased (P<0.05). The pull-out strength of the pedicle screw was increased with an increase in bone mineral density and trajectory bone cement. It peaked at 75% filling, with the largest power consumption. The optimal filling volume of the bone cement was 75% of the trajectory volume (about 1.03 mL). The use of excessive bone cement did not increase

High-fat diets affect energy and bone metabolism in growing rats.

PubMed

Macri, Elisa V; Gonzales Chaves, Macarena M; Rodriguez, Patricia N; Mandalunis, Patricia; Zeni, Susana; Lifshitz, Fima; Friedman, Silvia M

2012-06-01

High-fat diets are usually associated with greater weight (W) gain and body fat (BF). However, it is still unclear whether the type and amount of fat consumed influence BF. Additionally, dietary fat intake may also have consequences on skeletal health. To evaluate in healthy growing rats the effects of high-fat diets and type of dietary fat intake (saturated or vegetable oils) on energy and bone metabolism. At weaning, male Wistar rats (n = 50) were fed either a control diet (C; fat = 7% w/w) or a high-fat diet (20% w/w) containing either: soybean oil, corn oil (CO), linseed oil (LO), or beef tallow (BT) for 8 weeks. Zoometric parameters, BF, food intake and digestibility, and total and bone alkaline phosphatase (b-AP) were assessed. Total skeleton bone mineral density (BMD) and content (BMC), BMC/W, spine BMD, and bone volume (static-histomorphometry) were measured. Animals fed BT diet achieved lower W versus C. Rats fed high-fat vegetable oil diets showed similar effects on the zoometric parameters but differed in BF. BT showed the lowest lipid digestibility and BMC. In contrast, high vegetable oil diets produced no significant differences in BMC, BMC/W, BMD, spine BMD, and bone volume. Marked differences were observed for LO and BT groups in b-AP and CO and BT groups in bone volume. BT diet rich in saturated fatty acids had decreased digestibility and adversely affected energy and bone metabolisms, in growing healthy male rats. There were no changes in zoometric and bone parameters among rats fed high vegetable oil diets.

Composites structures for bone tissue reconstruction

NASA Astrophysics Data System (ADS)

Neto, W.; Santos, João.; Avérous, L.; Schlatter, G.; Bretas, Rosario.

2015-05-01

The search for new biomaterials in the bone reconstitution field is growing continuously as humane life expectation and bone fractures increase. For this purpose, composite materials with biodegradable polymers and hydroxyapatite (HA) have been used. A composite material formed by a film, nanofibers and HA has been made. Both, the films and the non-woven mats of nanofibers were formed by nanocomposites made of butylene adipate-co-terephthalate (PBAT) and HA. The techniques used to produce the films and nanofibers were spin coating and electrospinning, respectively. The composite production and morphology were evaluated. The composite showed an adequate morphology and fibers size to be used as scaffold for cell growth.

Symmetry analysis of talus bone: A Geometric morphometric approach.

PubMed

Islam, K; Dobbe, A; Komeili, A; Duke, K; El-Rich, M; Dhillon, S; Adeeb, S; Jomha, N M

2014-01-01

The main object of this study was to use a geometric morphometric approach to quantify the left-right symmetry of talus bones. Analysis was carried out using CT scan images of 11 pairs of intact tali. Two important geometric parameters, volume and surface area, were quantified for left and right talus bones. The geometric shape variations between the right and left talus bones were also measured using deviation analysis. Furthermore, location of asymmetry in the geometric shapes were identified. Numerical results showed that talus bones are bilaterally symmetrical in nature, and the difference between the surface area of the left and right talus bones was less than 7.5%. Similarly, the difference in the volume of both bones was less than 7.5%. Results of the three-dimensional (3D) deviation analyses demonstrated the mean deviation between left and right talus bones were in the range of -0.74 mm to 0.62 mm. It was observed that in eight of 11 subjects, the deviation in symmetry occurred in regions that are clinically less important during talus surgery. We conclude that left and right talus bones of intact human ankle joints show a strong degree of symmetry. The results of this study may have significance with respect to talus surgery, and in investigating traumatic talus injury where the geometric shape of the contralateral talus can be used as control. Cite this article: Bone Joint Res 2014;3:139-45.

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

PubMed

Bouleftour, Wafa; Boudiffa, Maya; Wade-Gueye, Ndeye Marième; Bouët, Guénaëlle; Cardelli, Marco; Laroche, Norbert; Vanden-Bossche, Arnaud; Thomas, Mireille; Bonnelye, Edith; Aubin, Jane E; Vico, Laurence; Lafage-Proust, Marie Hélène; Malaval, Luc

2014-01-01

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, while impairing

Assessment of bone healing ability of calcium phosphate cements loaded with platelet lysate in rat calvarial defects.

PubMed

Babo, Pedro S; Carvalho, Pedro P; Santo, Vítor E; Faria, Susana; Gomes, Manuela E; Reis, Rui L

2016-11-01

Injectable calcium phosphate cements have been used as a valid alternative to autologous bone grafts for bone augmentation with the additional advantage of enabling minimally invasive implantation procedures and for perfectly fitting the tissue defect. Nevertheless, they have low biodegradability and lack adequate biochemical signaling to promote bone healing and remodeling. In previous in vitro studies, we observed that the incorporation of platelet lysate directly into the cement paste or loaded in hyaluronic acid microspheres allowed to modulate the cement degradation and the in vitro expression of osteogenic markers in seeded human adipose derived stem cells. The present study aimed at investigating the possible effect of this system in new bone formation when implanted in calvarial bilateral defects in rats. Different formulations were assessed, namely plain calcium phosphate cements, calcium phosphate cements loaded with human platelet lysate, hybrid injectable formulations composed of the calcium phosphate cement incorporating hyaluronin acid non-loaded microparticles (20% hyaluronin acid) or with particles loaded with platelet lysate. The degradability and new bone regrowth were evaluated in terms of mineral volume in the defect, measured by micro-computed tomography and histomorphometric analysis upon 4, 8 and 12 weeks of implantation. We observed that the incorporation of hyaluronin acid microspheres induced an overly rapid cement degradation, impairing the osteoconductive properties of the cement composites. Moreover, the incorporation of platelet lysate induced higher bone healing than the materials without platelet lysate, up to four weeks after surgery. Nevertheless, this effect was not found to be significant when compared to the one observed in the sham-treated group. © The Author(s) 2016.

Ergonomic task reduction prevents bone osteopenia in a rat model of upper extremity overuse

PubMed Central

BARBE, Mary F.; JAIN, Nisha X.; MASSICOTTE, Vicky S.; POPOFF, Steven N.; BARR-GILLESPIE, Ann E.

2015-01-01

We evaluated the effectiveness of ergonomic workload reduction of switching rats from a high repetition high force (HRHF) lever pulling task to a reduced force and reach rate task for preventing task-induced osteopenic changes in distal forelimb bones. Distal radius and ulna trabecular structure was examined in young adult rats performing one of three handle-pulling tasks for 12 wk: 1) HRHF, 2) low repetition low force (LRLF); or 3) HRHF for 4 wk and than LRLF thereafter (HRHF-to-LRLF). Results were compared to age-matched controls rats. Distal forelimb bones of 12-wk HRHF rats showed increased trabecular resorption and decreased volume, as control rats. HRHF-to-LRLF rats had similar trabecular bone quality as control rats; and decreased bone resorption (decreased trabecular bone volume and serum CTX1), increased bone formation (increased mineral apposition, bone formation rate, and serum osteocalcin), and decreased osteoclasts and inflammatory cytokines, than HRHF rats. Thus, an ergonomic intervention of HRHF-to-LRLF prevented loss of trabecular bone volume occurring with prolonged performance of a repetitive upper extremity task. These findings support the idea of reduced workload as an effective approach to management of work-related musculoskeletal disorders, and begin to define reach rate and load level boundaries for such interventions. PMID:25739896

Effect of odanacatib on root resorption and alveolar bone metabolism during orthodontic tooth movement.

PubMed

Wei, X X; Chu, J P; Zou, Y Z; Ru, N; Cui, S X; Bai, Y X

2015-12-22

The aim of this study was to investigate the effect of local administration of odanacatib (ODN) on orthodontic root resorption and the status of alveolar bone metabolism in rat molars. All specimens were scanned using microcomputed tomography and then the raw images were reconstructed. The total volume of the root resorption craters of the 60 g-NS (normal saline) group was higher than in the 60 g-ODN group and the control group. In the 60 g-NS group, the bone volume fraction values of alveolar bone were significantly decreased compared with the other 2 groups. There were no significant differences in the bone volume fraction values of the tibiae among the 3 groups. The results of tartrate-resistant acid phosphatase-positive (TRAP+) numbers showed that there was no difference between the 60 g-NS group and the 60 g-ODN group. The expression of cathepsin K was decreased significantly in the 60 g-ODN group. These results indicate that ODN reduces orthodontics-induced external root resorption and increases alveolar bone metabolism. This may be because ODN inhibits the activity of odontoclasts, but maintains the quantity of odontoclasts and enhances bone formation. ODN promotes local alveolar bone metabolism, but does not affect systemic bone metabolism.

Are oral and maxillofacial surgery residents being adequately trained to care for pediatric patients?

PubMed

Abramowicz, Shelly; Kaban, Leonard B; Wurtzel, Andrew S; Roser, Steven M

2017-09-01

To evaluate whether current oral and maxillofacial surgery (OMS) residents are receiving adequate training and experience to perform specific surgical procedures and anesthesia for pediatric patients. A 17-question survey was sent electronically to fellows of the American Academy of Craniomaxillofacial Surgeons. Descriptive data for individual surgeons, their associated residency programs, and the quantity of specific pediatric procedures they performed were collected. Resident case load for inpatient and outpatient procedures and overall experience in medical, surgical, and anesthetic management of pediatric OMS patients were explored. Surveys were sent to 110 active fellows; 64 completed the questionnaire (58%). There were 59 male fellows and 5 female fellows, with a mean age of 50.4 years. Of those, 68.8% practice in an academic setting. Specifically, 93.8% take after-hours emergency calls covering adult and pediatric patients and 98.4% have admitting privileges at a children's hospital or a pediatric unit in an adult hospital. Their affiliated residency programs include required rotations in pediatrics or pediatric subspecialties. In their opinion, >90% of graduating OMS residents have the appropriate skill set to perform dentoalveolar procedures, outpatient anesthesia, orthognathic procedures, and alveolar bone grafts. However, residents have limited ability to reconstruct pediatric ramus-condyle unit with a costochondral graft. Results of this study indicate that, in the opinion of the respondents, graduates of OMS residency programs have adequate training to perform dentoalveolar procedures, outpatient anesthesia, orthognathic surgery, and alveolar bone grafts in pediatric procedures, but have limited experience with reconstruction of pediatric ramus-condyle unit via costochondral graft. Copyright © 2017 Elsevier Inc. All rights reserved.

Optimisation of composite bone plates for ulnar transverse fractures.

PubMed

Chakladar, N D; Harper, L T; Parsons, A J

2016-04-01

Metallic bone plates are commonly used for arm bone fractures where conservative treatment (casts) cannot provide adequate support and compression at the fracture site. These plates, made of stainless steel or titanium alloys, tend to shield stress transfer at the fracture site and delay the bone healing rate. This study investigates the feasibility of adopting advanced composite materials to overcome stress shielding effects by optimising the geometry and mechanical properties of the plate to match more closely to the bone. An ulnar transverse fracture is characterised and finite element techniques are employed to investigate the feasibility of a composite-plated fractured bone construct over a stainless steel equivalent. Numerical models of intact and fractured bones are analysed and the mechanical behaviour is found to agree with experimental data. The mechanical properties are tailored to produce an optimised composite plate, offering a 25% reduction in length and a 70% reduction in mass. The optimised design may help to reduce stress shielding and increase bone healing rates. Copyright © 2016 Elsevier Ltd. All rights reserved.

Polymeric scaffolds as stem cell carriers in bone repair.

PubMed

Rossi, Filippo; Santoro, Marco; Perale, Giuseppe

2015-10-01

Although bone has a high potential to regenerate itself after damage and injury, the efficacious repair of large bone defects resulting from resection, trauma or non-union fractures still requires the implantation of bone grafts. Materials science, in conjunction with biotechnology, can satisfy these needs by developing artificial bones, synthetic substitutes and organ implants. In particular, recent advances in polymer science have provided several innovations, underlying the increasing importance of macromolecules in this field. To address the increasing need for improved bone substitutes, tissue engineering seeks to create synthetic, three-dimensional scaffolds made from polymeric materials, incorporating stem cells and growth factors, to induce new bone tissue formation. Polymeric materials have shown a great affinity for cell transplantation and differentiation and, moreover, their structure can be tuned in order to maintain an adequate mechanical resistance and contemporarily be fully bioresorbable. This review emphasizes recent progress in polymer science that allows relaible polymeric scaffolds to be synthesized for stem cell growth in bone regeneration. Copyright © 2013 John Wiley & Sons, Ltd.

Bone vascularization and bone micro-architecture characterizations according to the μCT resolution

NASA Astrophysics Data System (ADS)

Crauste, E.; Autrusseau, F.; Guédon, Jp.; Pilet, P.; Amouriq, Y.; Weiss, P.; Giumelli, B.

2015-03-01

Trabecular bone and its micro-architecture are of prime importance for health. Changes of bone micro-architecture are linked to different pathological situations like osteoporosis and begin now to be understood. In a previous paper [12], we started to investigate the relationships between bone and vessels and proposed some indices of characterization for the vessels issued from those used for the bone. Our main objective in this paper is to qualify the classical values used for bone as well as those we proposed for vessels according to different acquisition parameters and for several thresholding methods used to separate bone vessels and background. This study is also based on vessels perfusion by a contrast agent (barium sulfate mixed with gelatin) before euthanasia on rats. Femurs and tibias as well as mandibles were removed after rat's death and were imaged by microCT (Skyscan 1272, Bruker, Belgium) with a resolution ranging from 18 to 3μm. The so obtained images were analyzed with various softwares (NRecon Reconstruction, CtAn, and CtVox from Bruker) in order to calculate bone and vessels micro-architecture parameters (density of bone/blood within the volume), and to know if the results both for bone and vascular micro-architecture are constant along the chosen pixel resolution. The result is clearly negative. We found a very different characterization both for bone and vessels with the 3μm acquisition. Tibia and mandibles bones were also used to show results that can be visually assessed. The largest portions of the vascular tree are orthogonal to the obtained slices of the bone. Therefore, the contrast agent appears as cylinders of various sizes.

Bisphosphonates inhibit bone remodeling in the jaw bones of rats and delay healing following tooth extractions.

PubMed

Jabbour, Zaher; El-Hakim, Michel; Henderson, Janet E; de Albuquerque, Rubens F

2014-05-01

This study aimed to evaluate the impact of concurrent administration of clinically relevant doses of zoledronic acid (ZA) and dexamethasone (DX) on bone healing after tooth extraction (EXO). Forty-four Sprague-Dawley rats (6-8 month old) were randomized into five groups: ZA + DX = weekly injection of ZA with DX for 7 weeks; WD = ZA with DX for 3 weeks then DX alone for 4 weeks; C = control saline for 7 weeks; ZA = ZA alone for 7 weeks and DX = DX alone for 7 weeks. ZA was administered at 0.13 mg/kg/week and DX at 3.8 mg/kg/week and body weights recorded at the time of injection. All rats underwent extraction (EXO) of the mandibular and maxillary first molars at 3 weeks and were euthanized at 7 weeks. The extracted and non-extracted sides of both jaws were harvested for micro-CT analyses. All rats, particularly those injected with ZA, exhibited weight gain till EXO followed by decline then recovery. ZA + DX group demonstrated highest fractional bone to tissue volume (BV/TV) in the non-extracted side. ZA + DX rats exhibited also highest volume and surface of sequestra. Only sequestra volume was statistically higher in the WD group compared to C group. Combined treatment with ZA and DX over a prolonged period inhibits bone remodeling and increased sequestra formation to a greater extent than either drug alone. Trauma caused by these sequestra cutting through the mucosa could play a key role in the development of BRONJ by potentially facilitating infection. ZA withdrawal may promote bone-remodeling reactivation following EXO. Copyright © 2014 Elsevier Ltd. All rights reserved.

Accuracy of DXA scanning of the thoracic spine: cadaveric studies comparing BMC, areal BMD and geometric estimates of volumetric BMD against ash weight and CT measures of bone volume.

PubMed

Sran, Meena M; Khan, Karim M; Keiver, Kathy; Chew, Jason B; McKay, Heather A; Oxland, Thomas R

2005-12-01

Biomechanical studies of the thoracic spine often scan cadaveric segments by dual energy X-ray absorptiometry (DXA) to obtain measures of bone mass. Only one study has reported the accuracy of lateral scans of thoracic vertebral bodies. The accuracy of DXA scans of thoracic spine segments and of anterior-posterior (AP) thoracic scans has not been investigated. We have examined the accuracy of AP and lateral thoracic DXA scans by comparison with ash weight, the gold-standard for measuring bone mineral content (BMC). We have also compared three methods of estimating volumetric bone mineral density (vBMD) with a novel standard-ash weight (g)/bone volume (cm3) as measured by computed tomography (CT). Twelve T5-T8 spine segments were scanned with DXA (AP and lateral) and CT. The T6 vertebrae were excised, the posterior elements removed and then the vertebral bodies were ashed in a muffle furnace. We proposed a new method of estimating vBMD and compared it with two previously published methods. BMC values from lateral DXA scans displayed the strongest correlation with ash weight (r=0.99) and were on average 12.8% higher (p<0.001). As expected, BMC (AP or lateral) was more strongly correlated with ash weight than areal bone mineral density (aBMD; AP: r=0.54, or lateral: r=0.71) or estimated vBMD. Estimates of vBMD with either of the three methods were strongly and similarly correlated with volumetric BMD calculated by dividing ash weight by CT-derived volume. These data suggest that readily available DXA scanning is an appropriate surrogate measure for thoracic spine bone mineral and that the lateral scan might be the scan method of choice.

[Stereological analysis of rat bone tissue after a flight on the Kosmos-1129 biosatellite].

PubMed

Prokhonchukov, A A; Peschanskiĭ, V S

1982-01-01

Stereological measurements of volume fractions of 53 samples of compact and spongy structures of bones of 15 rats were carried out. The measurements were performed on cortical lamellae, trabecules and lacunae, channels of osteons and matrices of femoral, tibial and fibular bones of rats. Postflight no significant changes were seen in the above parameters as compared to the vivarium controls. During readaptation to I g a slight increase in the volume fraction of spongy bones was noted.

Recommendations on the effect of antidiabetic drugs in bone.

PubMed

Rozas-Moreno, Pedro; Reyes-García, Rebeca; Jódar-Gimeno, Esteban; Varsavsky, Mariela; Luque-Fernández, Inés; Cortés-Berdonces, María; Muñoz-Torres, Manuel

2017-03-01

To provide recommendations on the effect of antidiabetic drugs on bone fragility to help select the most adequate antidiabetic treatment, especially in diabetic patients with high risk of fracture. Members of the Bone Metabolism Working Group of the Spanish Society of Endocrinology. The GRADE system (Grading of Recommendations, Assessment, Development, and Evaluation) was used to establish both the strength of recommendations and the quality of evidence. A systematic search was made in MEDLINE (Pubmed) using the following terms associated to the name of each antidiabetic drug: AND "osteoporosis", "fractures", "bone mineral density", "bone markers", "calciotropic hormones". Papers in English with publication date before 30 April 2016 were reviewed. Recommendations were jointly discussed by the Working Group. The document summaries the data on the potential effects of antidiabetic drugs on bone metabolism and fracture risk. Copyright © 2017 SEEN. Publicado por Elsevier España, S.L.U. All rights reserved.

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

PubMed

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

Acute peg in hole docking in the management of infected non-union of long bones.

PubMed

Dhar, Shabir Ahmed; Mir, Mohammed Ramzan; Ahmed, Molvi Sajjad; Afzal, Suhail; Butt, Mohammed Farooq; Badoo, A R; Dar, Irshad Tabasum; Hussain, Anwar

2008-08-01

The Ilizarov method has been studied extensively in the management of non-union of long bones. In most cases this involves filling of defects present primarily or after débridement by bone transport. Acute docking over gaps longer than 2 cm has not been adequately studied, however. The purpose of this paper is to report the efficacy of acute peg in hole docking as a bone graft-sparing modality in the management of infected non-union of long bones.

Acute peg in hole docking in the management of infected non-union of long bones

PubMed Central

Mir, Mohammed Ramzan; Ahmed, Molvi Sajjad; Afzal, Suhail; Butt, Mohammed Farooq; Badoo, A. R.; Dar, Irshad Tabasum; Hussain, Anwar

2007-01-01

The Ilizarov method has been studied extensively in the management of non-union of long bones. In most cases this involves filling of defects present primarily or after débridement by bone transport. Acute docking over gaps longer than 2 cm has not been adequately studied, however. The purpose of this paper is to report the efficacy of acute peg in hole docking as a bone graft-sparing modality in the management of infected non-union of long bones. PMID:17387474

Bone tumor location in dogs given skeletal irradiation by {sup 239}Pu or {sup 226}Ra

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lloyd, R.D.; Taylor, G.N.; Miller, S.C.

1997-10-01

Statistical analyses have indicated that there was a significant difference between dogs injected with bone volume-seeking {sup 226} Ra as compared to those given bone surface-seeking {sup 239}Pu with respect to location within the skeleton of 334 radiation-induced primary bone malignancies. Corresponding differences also were event when dogs given bone volume-seeking {sup 90}Sr or bone surface-seeking {sup 241}Am, {sup 228}Th {sup 248,252}Cf, or {sup 224}Ra (which decays mostly on bone surfaces because of its short, 3.6 d half time) were included along with the {sup 226}Ra or {sup 239}Pu, respectively (562 total tumors). Further analysis suggested that higher values ofmore » percent red marrow (M) and bone turnover rate (R) are correlated with increased probability. of tumor appearance at a particular location within the skeleton for the surface seekers. Proportionately higher values of M and R are associated with skeletal sites containing mostly trabecular bone as compared to those with mostly compact (cortical) bone. Coefficients of determination (r{sup 2}) for the relationship between percent of total tumors vs the combination of percent red marrow and turnover rate (= MR) was about 0.7 for the surface seekers but only about 0.1 for the volume seekers. This indicates that the neoplastic effects of surface seekers, but not volume seekers, are associated with the presence of trabecular bone at the various sites of radio nuclide deposition within the skeleton. 10 refs., 3 tabs.« less

Optimizing tamoxifen-inducible Cre/loxp system to reduce tamoxifen effect on bone turnover in long bones of young mice.

PubMed

Zhong, Zhendong A; Sun, Weihua; Chen, Haiyan; Zhang, Hongliang; Lay, Yu-An E; Lane, Nancy E; Yao, Wei

2015-12-01

For tamoxifen-dependent Cre recombinase, also known as CreER recombinase, tamoxifen (TAM) is used to activate the Cre to generate time- and tissue-specific mouse mutants. TAM is a potent CreER system inducer; however, TAM is also an active selective estrogen receptor modulator (SERM) that can influence bone homeostasis. The purpose of this study was to optimize the TAM dose for Cre recombinase activation while minimizing the effects of TAM on bone turnover in young growing mice. To evaluate the effects of TAM on bone turnover and bone mass, 1-month-old wild-type male and female mice were intraperitoneally injected with TAM at 0, 1, 10 or 100mg/kg/day for four consecutive days, or 100, 300 mg/kg/day for one day. The distal femurs were analyzed one month after the last TAM injection by microCT, mechanical test, and surface-based bone histomorphometry. Similar doses of TAM were used in Col1 (2.3 kb)-CreERT2; mT/mG reporter male mice to evaluate the dose-dependent efficacy of Cre-ER activation in bone tissue. A TAM dose of 100 mg/kg × 4 days significantly increased trabecular bone volume/total volume (BV/TV) of the distal femur, femur length, bone strength, and serum bone turnover markers compared to the 0mg control group. In contrast, TAM doses ≤ 10 mg/kg did not significantly change any of these parameters compared to the 0mg group, although a higher bone strength was observed in the 10mg group. Surface-based histomorphometry revealed that the 100mg/kg dose of TAM dose significantly increased trabecular bone formation and decreased periosteal bone formation at 1-week post-TAM treatment. Using the reporter mouse model Col1-CreERT2; mT/mG, we found that 10mg/kg TAM induced Col1-CreERT2 activity in bone at a comparable level to the 100mg/kg dose. TAM treatment at 100mg/kg/day × 4 days significantly affects bone homeostasis, resulting in an anabolic bone effect on trabecular bone in 1-month-old male mice. However, a lower dose of TAM at 10 mg/kg/day × 4 days can

Evaluating bone quality in patients with chronic kidney disease

PubMed Central

Malluche, Hartmut H.; Porter, Daniel S.; Pienkowski, David

2013-01-01

Bone of normal quality and quantity can successfully endure physiologically imposed mechanical loads. Chronic kidney disease–mineral and bone disorder (CKD–MBD) adversely affects bone quality through alterations in bone turnover and mineralization, whereas bone quantity is affected through changes in bone volume. Changes in bone quality can be associated with altered bone material, structure, or microdamage, which can result in an elevated rate of fracture in patients with CKD–MBD. Fractures cannot always be explained by reduced bone quantity and, therefore, bone quality should be assessed with a variety of techniques from the macro-organ level to the nanoscale level. In this Review, we demonstrate the importance of evaluating bone from multiple perspectives and hierarchical levels to understand CKD–MBD-related abnormalities in bone quality. Understanding the relationships between variations in material, structure, microdamage, and mechanical properties of bone in patients with CKD–MBD should aid in the development of new modalities to prevent, or treat, these abnormalities. PMID:24100399

Dietary Pseudopurpurin Improves Bone Geometry Architecture and Metabolism in Red-Bone Guishan Goats

PubMed Central

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

Bone curvature changes can predict the impact of treatment on cartilage volume loss in knee osteoarthritis: data from a 2-year clinical trial.

PubMed

Raynauld, Jean-Pierre; Pelletier, Jean-Pierre; Delorme, Philippe; Dodin, Pierre; Abram, François; Martel-Pelletier, Johanne

2017-06-01

Knee bone curvature assessed by MRI was associated with OA cartilage loss. A recent knee OA trial demonstrated the superiority of chondroitin sulfate over celecoxib (comparator) at reducing cartilage volume loss (CVL) in the medial compartment (condyle). The main objectives were to identify which baseline bone curvature regions of interest (BCROI) best associated with CVL and investigate whether baseline BCROI and 2-year change are correlated with the protective effect of chondroitin sulphate on CVL. This post hoc analysis of a clinical trial used the according-to-protocol population (chondroitin sulphate, n = 57; celecoxib, n = 63) baseline and 2-year MRI to assess bone curvature and CVL. Global optimum search identified the BCROI in the medial condyle using celecoxib as reference. Statistical analyses were performed with Pearson's correlation, Mann-Whitney U -test, Student's t -test and analysis of covariance. The BCROI including the medial posterior condyle and lateral central condyle was found to correlate best with medial condyle CVL at 2 years ( r = 0.33, P = 0.008). In patients with a baseline BCROI value less than the median (more flattened bone), chondroitin sulphate demonstrated a protective effect on CVL compared with celecoxib in the medial compartment (P = 0.037). In patients with 2-year BCROI changes greater than the median (greater severity of bone flattening), chondroitin sulphate protected against CVL in the medial compartment, condyle and central plateau (P ⩽ 0.030). This study is the first to demonstrate the feasibility and usefulness of bone curvature measurements to predict effectiveness of OA treatment on CVL. The results identify bone curvature as a potential novel biomarker for knee OA clinical trials. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Glucocorticoid induced osteopenia in cancellous bone of sheep: validation of large animal model for spine fusion and biomaterial research.

PubMed

Ding, Ming; Cheng, Liming; Bollen, Peter; Schwarz, Peter; Overgaard, Søren

2010-02-15

Glucocorticoid with low calcium and phosphorus intake induces osteopenia in cancellous bone of sheep. To validate a large animal model for spine fusion and biomaterial research. A variety of ovariectomized animals has been used to study osteoporosis. Most experimental spine fusions were based on normal animals, and there is a great need for suitable large animal models with adequate bone size that closely resemble osteoporosis in humans. Eighteen female skeletal mature sheep were randomly allocated into 3 groups, 6 each. Group 1 (GC-1) received prednisolone (GC) treatment (0.60 mg/kg/day, 5 times weekly) for 7 months. Group 2 (GC-2) received the same treatment as GC-1 for 7 months followed by 3 months without treatment. Group 3 was left untreated and served as the controls. All sheep received restricted diet with low calcium and phosphorus during experiment. After killing the animals, cancellous bone specimens from the vertebra, femurs, and tibias were micro-CT scanned and tested mechanically. Serum biomarkers were determined. In lumbar vertebra, the GC treatment resulted in significant decrease of cancellous bone volume fraction and trabecular thickness, and bone strength. However, the microarchitecture and bone strength of GC-2 recovered to a similar level of the controls. A similar trend of microarchitectural changes was also observed in the distal femur and proximal tibia of both GC treated sheep. The bone formation marker serum-osteocalcin was largely reduced in GC-1 compared to the controls, but recovered with a rebound increase at month 10 in GC-2. The current investigation demonstrates that the changes in microarchitecture and mechanical properties were comparable with those observed in humans after long-term GC treatment. A prolonged GC treatment is needed for a long-term observation to keep osteopenic bone. This model resembles long-term glucocorticoid treated osteoporotic model, and is useful in preclinical studies.

Differences in Non-Enzymatic Glycation and Collagen Crosslinks between Human Cortical and Cancellous Bone

PubMed Central

Karim, Lamya; Tang, Simon Y.; Sroga, Grażyna E.; Vashishth, Deepak

2015-01-01

Purpose Accumulation of collagen crosslinks (advanced glycation end products [AGEs]) produced by non-enzymatic glycation deteriorates bone's mechanical properties and fracture resistance. Although a single AGE, pentosidine, is commonly used as a representative marker, it is unclear whether it quantitatively reflects total fluorescent AGEs in bone. The goal of this study was to establish the relationship between pentosidine and total AGEs in cancellous and cortical bone. Methods Pentosidine and total AGEs were quantified in 170 human bone samples. Total fluorescent AGEs were measured in 28 additional cancellous and cortical bone specimens of the same apparent volume that were incubated in control or in vitro glycation solutions. Correlations between pentosidine and total AGEs and differences between cortical and cancellous groups were determined. Results Pentosidine was correlated with total AGEs in cancellous bone (r=0.53, p<0.0001) and weakly correlated in cortical bone (r=0.23, p<0.05). There was more pentosidine (p<0.01) and total AGEs (p<0.001) in cancellous than in cortical bone. The in vitro glycation sub-study showed that cancellous bone accumulated more AGEs than cortical bone (p<0.05). Conclusion The relationship between pentosidine and total AGEs and their magnitude of accumulation differed in cancellous and cortical bone of the same apparent volume, and were dependent on the surface-to-volume ratios of each sample. It is important to consider the bone types as two separate entities, and it is crucial to quantify total AGEs in addition to pentosidine to allow for more comprehensive analysis of the effects of non-enzymatic glycation in bone. PMID:23471564

Preservation and promotion of bone formation in the mandible as a response to a novel calcium-phosphate based biomaterial in mineral deficiency induced low bone mass male versus female rats

PubMed Central

Srinivasan, Kritika; Naula, Diana P.; Mijares, Dindo Q.; Janal, Malvin N.; LeGeros, Raquel Z.; Zhang, Yu

2016-01-01

Calcium and other trace mineral supplements have previously demonstrated to safely improve bone quality. We hypothesize that our novel calcium-phosphate based biomaterial (SBM) preserves and promotes mandibular bone formation in male and female rats on mineral deficient diet (MD). Sixty Sprague-Dawley rats were randomly assigned to receive one of three diets (n = 10): basic diet (BD), MD or mineral deficient diet with 2% SBM. Rats were sacrificed after 6 months. Micro-Computed Tomography (μCT) was used to evaluate bone volume and 3D-microarchitecture while microradiography (Faxitron) was used to measure bone mineral density from different sections of the mandible. Results showed that bone quality varied with region, gender and diet. MD reduced bone mineral density (BMD) and volume and increased porosity. SBM preserved BMD and bone mineral content (BMC) in the alveolar bone and condyle in both genders. In the alveolar crest and mandibular body, while preserving more bone in males, SBM also significantly supplemented female bone. Results indicate that mineral deficiency leads to low bone mass in skeletally immature rats, comparatively more in males. Furthermore, SBM administered as a dietary supplement was effective in preventing mandibular bone loss in all subjects. This study suggests that the SBM preparation has potential use in minimizing low peak bone mass induced by mineral deficiency and related bone loss irrespective of gender. PMID:26914814

Vitamins and bone health: beyond calcium and vitamin D.

PubMed

Ahmadieh, Hala; Arabi, Asma

2011-10-01

Osteoporosis is a major health disorder associated with an increased risk of fracture. Nutrition is among the modifiable factors that influence the risk of osteoporosis and fracture. Calcium and vitamin D play important roles in improving bone mineral density and reducing the risk of fracture. Other vitamins appear to play a role in bone health as well. In this review, the findings of studies that related the intake and/or the status of vitamins other than vitamin D to bone health in animals and humans are summarized. Studies of vitamin A showed inconsistent results. Excessive, as well as insufficient, levels of retinol intake may be associated with compromised bone health. Deficiencies in vitamin B, along with the consequent elevated homocysteine level, are associated with bone loss, decreased bone strength, and increased risk of fracture. Deficiencies in vitamins C, E, and K are also associated with compromised bone health; this effect may be modified by smoking, estrogen use or hormonal therapy after menopause, calcium intake, and vitamin D. These findings highlight the importance of adequate nutrition in preserving bone mass and reducing the risk of osteoporosis and fractures. © 2011 International Life Sciences Institute.

Laminated electrospun nHA/PHB-composite scaffolds mimicking bone extracellular matrix for bone tissue engineering.

PubMed

Chen, Zhuoyue; Song, Yue; Zhang, Jing; Liu, Wei; Cui, Jihong; Li, Hongmin; Chen, Fulin

2017-03-01

Electrospinning is an effective means to generate nano- to micro-scale polymer fibers resembling native extracellular matrix for tissue engineering. However, a major problem of electrospun materials is that limited pore size and porosity may prevent adequate cellular infiltration and tissue ingrowth. In this study, we first prepared thin layers of hydroxyapatite nanoparticle (nHA)/poly-hydroxybutyrate (PHB) via electrospinning. We then laminated the nHA/PHB thin layers to obtain a scaffold for cell seeding and bone tissue engineering. The results demonstrated that the laminated scaffold possessed optimized cell-loading capacity. Bone marrow mesenchymal stem cells (MSCs) exhibited better adherence, proliferation and osteogenic phenotypes on nHA/PHB scaffolds than on PHB scaffolds. Thereafter, we seeded MSCs onto nHA/PHB scaffolds to fabricate bone grafts. Histological observation showed osteoid tissue formation throughout the scaffold, with most of the scaffold absorbed in the specimens 2months after implantation, and blood vessels ingrowth into the graft could be observed in the graft. We concluded that electrospun and laminated nanoscaled biocomposite scaffolds hold great therapeutic potential for bone regeneration. Copyright © 2016 Elsevier B.V. All rights reserved.

Bone Loss from High Repetitive High Force Loading is Prevented by Ibuprofen Treatment

PubMed Central

Jain, Nisha X.; Barr-Gillespie, Ann E.; Clark, Brian D.; Kietrys, David M.; Wade, Christine K.; Litvin, Judith; Popoff, Steven N.; Barbe, Mary F.

2014-01-01

We examined roles of loading and inflammation on forearm bones in a rat model of upper extremity overuse. Trabecular structure in distal radius and ulna was examined in three groups of young adult rats: 1) 5% food-restricted that underwent an initial training period of 10 min/day for 5 weeks to learn the repetitive task (TRHF); 2) rats that underwent the same training before performing a high repetition high force task, 2 hours/day for 12 weeks (HRHF); and 3) food-restricted only (FRC). Subsets were treated with oral ibuprofen (IBU). TRHF rats had increased trabecular bone volume and numbers, osteoblasts, and serum osteocalcin, indicative of bone adaptation. HRHF rats had constant muscle pulling forces, showed limited signs of bone adaptation, but many signs of bone resorption, including decreased trabecular bone volume and bone mineral density, increased osteoclasts and bone inflammatory cytokines, and reduced median nerve conduction velocity (15%). HRHF+IBU rats showed no trabecular resorptive changes, no increased osteoclasts or bone inflammatory cytokines, no nerve inflammation, preserved nerve conduction, and increased muscle voluntary pulling forces. Ibuprofen treatment preserved trabecular bone quality by reducing osteoclasts and bone inflammatory cytokines, and improving muscle pulling forces on bones as a result of reduced nerve inflammation. PMID:24583543

Bone augmentation for cancellous bone- development of a new animal model

PubMed Central

2013-01-01

Background Reproducible and suitable animal models are required for in vivo experiments to investigate new biodegradable and osteoinductive biomaterials for augmentation of bones at risk for osteoporotic fractures. Sheep have especially been used as a model for the human spine due to their size and similar bone metabolism. However, although sheep and human vertebral bodies have similar biomechanical characteristics, the shape of the vertebral bodies, the size of the transverse processes, and the different orientation of the facet joints of sheep are quite different from those of humans making the surgical approach complicated and unpredictable. Therefore, an adequate and safe animal model for bone augmentation was developed using a standardized femoral and tibia augmentation site in sheep. Methods The cancellous bone of the distal femur and proximal tibia were chosen as injection sites with the surgical approach via the medial aspects of the femoral condyle and proximal tibia metaphysis (n = 4 injection sites). For reproducible drilling and injection in a given direction and length, a custom-made c-shaped aiming device was designed. Exact positioning of the aiming device and needle positioning within the intertrabecular space of the intact bone could be validated in a predictable and standardized fashion using fluoroscopy. After sacrifice, bone cylinders (∅ 32 mm) were harvested throughout the tibia and femur by means of a diamond-coated core drill, which was especially developed to harvest the injected bone area exactly. Thereafter, the extracted bone cylinders were processed as non-decalcified specimens for μCT analysis, histomorphometry, histology, and fluorescence evaluation. Results The aiming device could be easily placed in 63 sheep and assured a reproducible, standardized injection area. In four sheep, cardiovascular complications occurred during surgery and pulmonary embolism was detected by computed tomography post surgery in all of these animals

Bone augmentation for cancellous bone- development of a new animal model.

PubMed

Klein, Karina; Zamparo, Enrico; Kronen, Peter W; Kämpf, Katharina; Makara, Mariano; Steffen, Thomas; von Rechenberg, Brigitte

2013-07-02

Reproducible and suitable animal models are required for in vivo experiments to investigate new biodegradable and osteoinductive biomaterials for augmentation of bones at risk for osteoporotic fractures. Sheep have especially been used as a model for the human spine due to their size and similar bone metabolism. However, although sheep and human vertebral bodies have similar biomechanical characteristics, the shape of the vertebral bodies, the size of the transverse processes, and the different orientation of the facet joints of sheep are quite different from those of humans making the surgical approach complicated and unpredictable. Therefore, an adequate and safe animal model for bone augmentation was developed using a standardized femoral and tibia augmentation site in sheep. The cancellous bone of the distal femur and proximal tibia were chosen as injection sites with the surgical approach via the medial aspects of the femoral condyle and proximal tibia metaphysis (n = 4 injection sites). For reproducible drilling and injection in a given direction and length, a custom-made c-shaped aiming device was designed. Exact positioning of the aiming device and needle positioning within the intertrabecular space of the intact bone could be validated in a predictable and standardized fashion using fluoroscopy. After sacrifice, bone cylinders (Ø 32 mm) were harvested throughout the tibia and femur by means of a diamond-coated core drill, which was especially developed to harvest the injected bone area exactly. Thereafter, the extracted bone cylinders were processed as non-decalcified specimens for μCT analysis, histomorphometry, histology, and fluorescence evaluation. The aiming device could be easily placed in 63 sheep and assured a reproducible, standardized injection area. In four sheep, cardiovascular complications occurred during surgery and pulmonary embolism was detected by computed tomography post surgery in all of these animals. The harvesting and evaluative

Reconstruction of Traumatic Bone Defect With In Situ Implantation of Dropped Traumatic Segmental Bone Fragments.

PubMed

Lin, Dasheng; Luo, Deqing; Lian, Kejian; Zhai, Wenliang; Ding, Zhenqi

2016-01-01

This study was conducted to determine whether in situ implantation of a dropped traumatic segmental bone fragment is safe and whether the authors' method would reduce the incidence of infectious and related complications. The authors retrospectively reviewed 16 patients with open fractures, including 11 with Gustilo-Anderson type IIIA fractures and 5 with Gustilo-Anderson type IIIB fractures who had a dropped traumatic segmental bone fragment between January 2002 and January 2012. Mean patient age was 35.4 years (range, 19-47 years). There were 10 femurs and 6 tibias. Average postoperative follow-up was 26.8 months (range, 12-60 months). The dropped traumatic segmental bone fragments were cleaned with 3% hydrogen peroxide, placed in separate sterile cups, and soaked in 1% iodophor for 30 minutes. Initial treatment included surgical debridement, wound irrigation, in situ implantation of the dropped traumatic segmental bone fragment, and temporary external fixation. Approximately 4 to 8 weeks later, after successful reconstruction of the soft tissue envelope, minimally invasive plate osteosynthesis was performed. Mean duration of treatment was 8 weeks (range, 6-14 weeks). All patients had fracture union at final follow-up. Mean healing time was 21.8 weeks (range, 14-48 weeks). One patient did not achieve primary union and required bone grafting. One patient with a Gustilo-Anderson type IIIB fracture had deep infection and removal of the dropped traumatic segmental bone fragment and bone grafting. According to the Klemm and Börner classification, 11 patients had excellent results, 3 had good results, and 2 had poor results. With adequate soft tissue coverage, this method was acceptable for the management of open fractures with bone defects. Copyright 2016, SLACK Incorporated.

High-resolution-cone beam tomography analysis of bone microarchitecture in patients with acromegaly and radiological vertebral fractures.

PubMed

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 < 0.05) lower bone volume/trabecular volume ratio, greater mean trabecular separation, and higher cortical porosity vs. nonfractured patients, without statistically significant differences in mean trabecular thickness and cortical thickness. Fractured and nonfractured 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 < 0.001) and greater mean trabecular separation (p = 0.02) as compared to control subjects, without significant differences in cortical thickness and porosity. This study shows for the first time that abnormalities of bone microstructure are associated with radiological vertebral fractures in acromegaly. High-resolution cone-beam computed tomography at the distal radius may be useful to evaluate and predict the effects of acromegaly on bone

Experimental model of bone response to collagenized xenografts of porcine origin (OsteoBiol® mp3): a radiological and histomorphometric study.

PubMed

Calvo Guirado, Jose Luis; Ramírez Fernández, Maria Piedad; Negri, Bruno; Delgado Ruiz, Rafael Arcesio; Maté Sánchez de-Val, José Eduardo; Gómez-Moreno, Gerardo

2013-02-01

Adequate alveolar ridges are fundamental to successful rehabilitation with implants. There are diverse techniques for reconstructing atrophied ridges, of which bone substitute grafts is one possibility. The aim of this study was to carry out radiological and histomorphometric evaluations of bone response to collagenized porcine bone xenografts over a 4-month period following their insertion in rabbits' tibiae. Twenty New Zealand rabbits were used. Twenty collagenized porcine bone xenografts (Osteobiol® mp3, Tecnoss Dental s.r.l., Torino, Italy), in granulated form of 600 to 1,000 µm, were inserted in the proximal metaphyseal area of the animals' tibiae and 20 control areas were created. Following implantation, the animals were sacrificed in four groups of five, after 1, 2, 3, and 4 months, respectively. Radiological and histomorphometric studies were made. After 4 months, radiological images revealed bone defects with a decrease in graft volume and the complete repair of the osseous defect. No healed or residual bone alterations attributable to the presence of the implants were observed. Histomorphometric analysis at 4 months found mean values for newly formed bone, residual graft material, and non-mineralized connective tissue of 25.4 ± 1.8%, 36.37 ± 3.0%, and 38.22 ± 2.5%, respectively. There were no statistical differences in the length of cortical formation with collagenized porcine xenograft (98.9 ± 1.1%) compared with the control samples (99.1 ± 0.7%) at the end of the study period. The biomaterial used proved to be biocompatible, bioabsorbable, and osteoconductive and as such, a possible bone substitute that did not interfere with the bone's normal reparative processes. © 2011 Wiley Periodicals, Inc.

Localized tissue mineralization regulated by bone remodelling: A computational approach

PubMed Central

Decco, Oscar; Adams, George; Cook, Richard B.; García Aznar, José Manuel

2017-01-01

Bone is a living tissue whose main mechanical function is to provide stiffness, strength and protection to the body. Both stiffness and strength depend on the mineralization of the organic matrix, which is constantly being remodelled by the coordinated action of the bone multicellular units (BMUs). Due to the dynamics of both remodelling and mineralization, each sample of bone is composed of structural units (osteons in cortical and packets in cancellous bone) created at different times, therefore presenting different levels of mineral content. In this work, a computational model is used to understand the feedback between the remodelling and the mineralization processes under different load conditions and bone porosities. This model considers that osteoclasts primarily resorb those parts of bone closer to the surface, which are younger and less mineralized than older inner ones. Under equilibrium loads, results show that bone volumes with both the highest and the lowest levels of porosity (cancellous and cortical respectively) tend to develop higher levels of mineral content compared to volumes with intermediate porosity, thus presenting higher material densities. In good agreement with recent experimental measurements, a boomerang-like pattern emerges when plotting apparent density at the tissue level versus material density at the bone material level. Overload and disuse states are studied too, resulting in a translation of the apparent–material density curve. Numerical results are discussed pointing to potential clinical applications. PMID:28306746

The Impact of Sweat Calcium Loss on Bone Health in Soldiers: A Pilot Study

DTIC Science & Technology

2013-02-06

correlated to total calories, carbohydrate, fat , and protein intake. For Group 1 (Medical) overall diet did not have an impact on bone density. For Group...baseline heel bone density for this group we do not know if the diet , high in calories, protein, and carbohydrates, with adequate amounts of calcium...FH. (2010). Acid diet ( high -meat protein) effects on calcium metabolism and bone health. Curr Opin Clin Nutr Metab Care, 13(6):698-702. Cizza, G

Mandibular Reconstruction with Lateral Tibial Bone Graft: An Excellent Option for Oral and Maxillofacial Surgery.

PubMed

Miceli, Ana Lucia Carpi; Pereira, Livia Costa; Torres, Thiago da Silva; Calasans-Maia, Mônica Diuana; Louro, Rafael Seabra

2017-12-01

Autogenous bone grafts are the gold standard for reconstruction of atrophic jaws, pseudoarthroses, alveolar clefts, orthognathic surgery, mandibular discontinuity, and augmentation of sinus maxillary. Bone graft can be harvested from iliac bone, calvarium, tibial bone, rib, and intraoral bone. Proximal tibia is a common donor site with few reported problems compared with other sites. The aim of this study was to evaluate the use of proximal tibia as a donor area for maxillofacial reconstructions, focusing on quantifying the volume of cancellous graft harvested by a lateral approach and to assess the complications of this technique. In a retrospective study, we collected data from 31 patients, 18 women and 13 men (mean age: 36 years, range: 19-64), who were referred to the Department of Oral and Maxillofacial Surgery at the Servidores do Estado Federal Hospital. Patients were treated for sequelae of orthognathic surgery, jaw fracture, nonunion, malunion, pathology, and augmentation of bone volume to oral implant. The technique of choice was lateral access of proximal tibia metaphysis for graft removal from Gerdy tubercle under general anesthesia. The mean volume of bone harvested was 13.0 ± 3.7 mL (ranged: 8-23 mL). Only five patients (16%) had minor complications, which included superficial infection, pain, suture dehiscence, and unwanted scar. However, none of these complications decreases the result and resolved completely. We conclude that proximal tibia metaphysis for harvesting cancellous bone graft provides sufficient volume for procedures in oral and maxillofacial surgery with minimal postoperative morbidity.

Composites structures for bone tissue reconstruction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neto, W.; Santos, João; Avérous, L.

2015-05-22

The search for new biomaterials in the bone reconstitution field is growing continuously as humane life expectation and bone fractures increase. For this purpose, composite materials with biodegradable polymers and hydroxyapatite (HA) have been used. A composite material formed by a film, nanofibers and HA has been made. Both, the films and the non-woven mats of nanofibers were formed by nanocomposites made of butylene adipate-co-terephthalate (PBAT) and HA. The techniques used to produce the films and nanofibers were spin coating and electrospinning, respectively. The composite production and morphology were evaluated. The composite showed an adequate morphology and fibers size tomore » be used as scaffold for cell growth.« less

Feasibility and performance of novel software to quantify metabolically active volumes and 3D partial volume corrected SUV and metabolic volumetric products of spinal bone marrow metastases on 18F-FDG-PET/CT.

PubMed

Torigian, Drew A; Lopez, Rosa Fernandez; Alapati, Sridevi; Bodapati, Geetha; Hofheinz, Frank; van den Hoff, Joerg; Saboury, Babak; Alavi, Abass

2011-01-01

Our aim was to assess feasibility and performance of novel semi-automated image analysis software called ROVER to quantify metabolically active volume (MAV), maximum standardized uptake value-maximum (SUV(max)), 3D partial volume corrected mean SUV (cSUV(mean)), and 3D partial volume corrected mean MVP (cMVP(mean)) of spinal bone marrow metastases on fluorine-18 fluorodeoxyglucose-positron emission tomography/computerized tomography ((18)F-FDG-PET/CT). We retrospectively studied 16 subjects with 31 spinal metastases on FDG-PET/CT and MRI. Manual and ROVER determinations of lesional MAV and SUV(max), and repeated ROVER measurements of MAV, SUV(max), cSUV(mean) and cMVP(mean) were made. Bland-Altman and correlation analyses were performed to assess reproducibility and agreement. Our results showed that analyses of repeated ROVER measurements revealed MAV mean difference (D)=-0.03±0.53cc (95% CI(-0.22, 0.16)), lower limit of agreement (LLOA)=-1.07cc, and upper limit of agreement (ULOA)=1.01cc; SUV(max) D=0.00±0.00 with LOAs=0.00; cSUV(mean) D=-0.01±0.39 (95% CI(-0.15, 0.13)), LLOA=-0.76, and ULOA=0.75; cMVP(mean) D=-0.52±4.78cc (95% CI(-2.23, 1.23)), LLOA=-9.89cc, and ULOA=8.86cc. Comparisons between ROVER and manual measurements revealed volume D= -0.39±1.37cc (95% CI (-0.89, 0.11)), LLOA=-3.08cc, and ULOA=2.30cc; SUV(max) D=0.00±0.00 with LOAs=0.00. Mean percent increase in lesional SUV(mean) and MVP(mean) following partial volume correction using ROVER was 84.25±36.00% and 84.45±35.94% , respectively. In conclusion, it is feasible to estimate MAV, SUV(max), cSUV(mean), and cMVP(mean) of spinal bone marrow metastases from (18)F-FDG-PET/CT quickly and easily with good reproducibility via ROVER software. Partial volume correction is imperative, as uncorrected SUV(mean) and MVP(mean) are significantly underestimated, even for large lesions. This novel approach has great potential for practical, accurate, and precise combined structural-functional PET

Ultraviolet-C irradiation to titanium implants increases peri-implant bone formation without impeding mineralization in a rabbit femur model.

PubMed

Yamazaki, Makoto; Yamada, Masahiro; Ishizaki, Ken; Sakurai, Kaoru

2015-05-01

Volume and bone quality of peri-implant supporting bone, in particular, at implant neck region, as well as bone-implant contact ratio, is important for long-term stability of implants. Ultraviolet-C (UVC) irradiation is known to enhance the osseointegration capability of titanium implants. However, the histological determination was performed only on a rat model, but not pre-clinical animal model such as a rabbit model. The purpose of this study was to determine the effects of UVC irradiation on titanium implants on the volume and mineral density of peri-implant supporting bone formation in a rabbit femur model. Acid-etched pure titanium screw implants with or without 3 mW/cm2 UVC irradiation for 48 h were placed in rabbit femur diaphyses. Peri-implant bone tissue formation was analyzed at 3 and 8 weeks post-operatively by histology and micro-CT-based bone morphometry after calibration with hydroxyl apatite phantoms. UVC pre-irradiated implants accumulated a higher density of cells and thicker and longer bone tissue attachments that continued into the inner basic lamellae of the surface of existing cortical bone at 3 and 8 weeks than the implants without irradiation. Although the bone mineral density around both implants was equivalent to that of the existing cortical bone, bone volume was greater with UVC pre-irradiation in two-thirds or more of the apical region throughout the observation period. These results indicate that UVC treatment increased the volume of cortical-like bone tissue in the coronal region of titanium implants without deterioration of bone mineral density.

Improvement of cancellous bone microstructure in patients on teriparatide following alendronate pretreatment.

PubMed

Fahrleitner-Pammer, Astrid; Burr, David; Dobnig, Harald; Stepan, Jan J; Petto, Helmut; Li, Jiliang; Krege, John H; Pavo, Imre

2016-08-01

An increase in procollagen type I amino-terminal propeptide (PINP) early after teriparatide initiation was shown to correlate with increased lumbar spine areal BMD and is a good predictor of the anabolic response to teriparatide. Few data exist correlating PINP and bone microstructure, and no data exist in patients on teriparatide following prior potent antiresorptive treatment. This exploratory analysis aimed to investigate the effects of teriparatide on cancellous bone microstructure and correlations of bone markers with microstructure in alendronate-pretreated patients. This was a post hoc analysis of changes in bone markers and three-dimensional indices of bone microstructure in paired iliac crest biopsies from a prospective teriparatide treatment study in postmenopausal women with osteoporosis who were either treatment-naïve (TN, n=16) or alendronate-pretreated (ALN, n=29) at teriparatide initiation. Teriparatide (20μg/day) was given for 24months; biopsies were taken at baseline and endpoint, and serum concentrations of PINP and type 1 collagen cross-linked C-telopeptide (βCTX) were measured at intervals up to 24months. In the TN and ALN groups, respectively, mean (SD) increases in three-dimensional bone volume/tissue volume were 105 (356)% (P=0.039) and 55 (139)% (P<0.005) and trabecular thickness 30.4 (30)% (P<0.001) and 30.8 (53)% (P<0.001). No significant changes were observed in trabecular number or separation. In the ALN patients, 3-month change of neither PINP nor βCTX correlated with indices of cancellous bone microstructure. However, 12-month changes in biochemical bone markers correlated significantly with improvements in bone volume/tissue volume, r=0.502 (P<0.01) and r=0.378 (P<0.05), trabecular number, r=0.559 (P<0.01) and r=0.515 (P<0.01), and reduction of trabecular separation, r=-0.432 (P<0.05) and r=-0.530 (P<0.01), for PINP and βCTX, respectively. We conclude that cancellous bone microstructure improved with teriparatide therapy

Preliminary Testing of a Compact, Bone-Attached Robot for Otologic Surgery

PubMed Central

Dillon, Neal P.; Balachandran, Ramya; dit Falisse, Antoine Motte; Wanna, George B.; Labadie, Robert F.; Withrow, Thomas J.; Fitzpatrick, J. Michael; Webster, Robert J.

2014-01-01

Otologic surgery often involves a mastoidectomy procedure, in which part of the temporal bone is milled away in order to visualize critical structures embedded in the bone and safely access the middle and inner ear. We propose to automate this portion of the surgery using a compact, bone-attached milling robot. A high level of accuracy is required to avoid damage to vital anatomy along the surgical path, most notably the facial nerve, making this procedure well-suited for robotic intervention. In this study, several of the design considerations are discussed and a robot design and prototype are presented. The prototype is a 4 degrees-of-freedom robot similar to a four-axis milling machine that mounts to the patient’s skull. A positioning frame, containing fiducial markers and attachment points for the robot, is rigidly attached to the skull of the patient, and a CT scan is acquired. The target bone volume is manually segmented in the CT by the surgeon and automatically converted to a milling path and robot trajectory. The robot is then attached to the positioning frame and is used to drill the desired volume. The accuracy of the entire system (image processing, planning, robot) was evaluated at several critical locations within or near the target bone volume with a mean free space accuracy result of 0.50 mm or less at all points. A milling test in a phantom material was then performed to evaluate the surgical workflow. The resulting milled volume did not violate any critical structures. PMID:25477726

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

PubMed

Yan, Lin; Yee, John A; Cao, Jay

2013-08-01

The present study investigated the effects of curcumin on bone microstructure in non-tumor-bearing and Lewis lung carcinoma-(LLC)-bearing female C57BL/6 mice. Morphometric analysis showed that dietary supplementation with curcumin (2% or 4%) significantly reduced the bone volume to total volume ratio, connectivity density and trabecular number, and significantly increased the structure model index (an indicator of the plate- and rod-like geometry of trabecular structure) and trabecular separation in vertebral bodies compared to controls in both non-tumor-bearing and LLC-bearing mice. Similar changes in trabecular bone were observed in the femoral bone in curcumin-fed mice. Curcumin significantly reduced the cortical bone area to total area ratio and cortical thickness in femoral mid-shaft, but not in vertebral bodies, in both non-tumor-bearing and LLC-bearing mice. Curcumin feeding reduced plasma concentrations of osteocalcin and increased tartrate-resistant acid phosphate 5b in mice regardless of the presence of LLC, indicating that curcumin disrupts the balance of bone remodeling. Our results demonstrated that curcumin reduced the trabecular bone volume and cortical bone density. The skeleton is a favored site of metastasis for many types of cancers, and curcumin has been investigated in clinical trials in patients with cancer for its chemopreventive effects. Our results suggest the possibility of a combined effect of cancer-induced osteolysis and curcumin-stimulated bone loss in patients using curcumin. The assessment of bone structural changes should be considered for those who participate in curcumin clinical trials to determine its effects on skeleton health, particularly for those with advanced malignancies.

How to deal with bone exposure and osteomyelitis: an overview.

PubMed

Verhelle, Nicolas; Van Zele, Dirk; Liboutton, Laurent; Heymans, Olivier

2003-12-01

The authors present an overview of the various techniques which can be used to achieve coverage of exposed bone, particularly in cases of bone exposure associated with an underlying fracture or osteomyelitis. Adequate debridement, possibly in several stages, is necessary in all cases to prepare the receptor site for the next step which is soft tissue coverage, achieved using various types of surgical procedures. Adequate reconstruction can be achieved with pedicled flaps in some cases but in cases with exposure of bone, free flaps usually represent a better option in cases where the condition of the patient is not a limiting factor. Thin fascio-cutaneous free flaps may be used in some cases with small and simple soft tissue loss, so as to minimise donor site mobidity. Free muscle flaps, such as from the latissimus dorsi, are preferable in cases with bone loss in order to fill any dead space; in cases with major bone loss, a free vascularised bone graft can be used, or composite grafts including bone, muscle and/or skin (fibula or crista iliaca flaps). Some reconstructions require a functional approach, such as over an exposed joint, or for the weight-bearing area of the foot or the soft tissues over the Achilles tendon. Survival of a free flap requires perfect, permeable microsutures; thrombosis of the anastomosis is a major complication which jeopardizes flap survival; close surveillance of the flap is required during the first few days, with hourly Doppler monitoring of the pedicle on the first day. The success rate can be as high as 90 to 100% in simple cases; failures may be related to surgical technique, inadequate choice of the flap, or specific features of the patient. In cases with an underlying bone infection, recurrence of infection occurs in 5 to 20% of cases; this requires additional treatment, possibly with repeat debridement, prolonged antibiotic therapy and sometimes a second free flap.

Dosimetric Comparison of Bone Marrow-Sparing Intensity-Modulated Radiotherapy Versus Conventional Techniques for Treatment of Cervical Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mell, Loren K.; Tiryaki, Hanifi; Ahn, Kang-Hyun

2008-08-01

Purpose: To compare bone marrow-sparing intensity-modulated pelvic radiotherapy (BMS-IMRT) with conventional (four-field box and anteroposterior-posteroanterior [AP-PA]) techniques in the treatment of cervical cancer. Methods and Materials: The data from 7 cervical cancer patients treated with concurrent chemotherapy and IMRT without BMS were analyzed and compared with data using four-field box and AP-PA techniques. All plans were normalized to cover the planning target volume with the 99% isodose line. The clinical target volume consisted of the pelvic and presacral lymph nodes, uterus and cervix, upper vagina, and parametrial tissue. Normal tissues included bowel, bladder, and pelvic bone marrow (PBM), which comprisedmore » the lumbosacral spine and ilium and the ischium, pubis, and proximal femora (lower pelvis bone marrow). Dose-volume histograms for the planning target volume and normal tissues were compared for BMS-IMRT vs. four-field box and AP-PA plans. Results: BMS-IMRT was superior to the four-field box technique in reducing the dose to the PBM, small bowel, rectum, and bladder. Compared with AP-PA plans, BMS-IMRT reduced the PBM volume receiving a dose >16.4 Gy. BMS-IMRT reduced the volume of ilium, lower pelvis bone marrow, and bowel receiving a dose >27.7, >18.7, and >21.1 Gy, respectively, but increased dose below these thresholds compared with the AP-PA plans. BMS-IMRT reduced the volume of lumbosacral spine bone marrow, rectum, small bowel, and bladder at all dose levels in all 7 patients. Conclusion: BMS-IMRT reduced irradiation of PBM compared with the four-field box technique. Compared with the AP-PA technique, BMS-IMRT reduced lumbosacral spine bone marrow irradiation and reduced the volume of PBM irradiated to high doses. Therefore BMS-IMRT might reduce acute hematologic toxicity compared with conventional techniques.« less

Enhancement of the repair of dog alveolar cleft by an autologous iliac bone, bone marrow-derived mesenchymal stem cell, and platelet-rich fibrin mixture.

PubMed

Yuanzheng, Chen; Yan, Gao; Ting, Li; Yanjie, Fu; Peng, Wu; Nan, Bai

2015-05-01

Autologous bone graft has been regarded as the criterion standard for the repair of alveolar cleft. However, the most prominent issue in alveolar cleft treatment is the high absorption rate of the bone graft. The authors' objective was to investigate the effects of an autologous iliac bone, bone marrow-derived mesenchymal stem cell, and platelet-rich fibrin mixture on the repair of dog alveolar cleft. Twenty beagle dogs with unilateral alveolar clefts created by surgery were divided randomly into four groups: group A underwent repair with an autologous iliac bone, bone marrow-derived mesenchymal stem cell, and platelet-rich fibrin mixture; group B underwent repair with autologous iliac bone and bone marrow-derived mesenchymal stem cells; group C underwent repair with autologous iliac bone and platelet-rich fibrin; and group D underwent repair with autologous iliac bone as the control. One day and 6 months after transplantation, the transplant volumes and bone mineral density were assessed by quantitative computed tomography. All of the transplants were harvested for hematoxylin and eosin staining 6 months later. Bone marrow-derived mesenchymal stem cells and platelet-rich fibrin transplants formed the greatest amounts of new bone among the four groups. The new bone formed an extensive union with the underlying maxilla in groups A, B, and C. Transplants with the bone marrow-derived mesenchymal stem cells, platelet-rich fibrin, and their mixture retained the majority of their initial volume, whereas the transplants in the control group showed the highest absorption rate. Bone mineral density of transplants with the bone marrow-derived mesenchymal stem cells, platelet-rich fibrin, and their mixture 6 months later was significantly higher than in the control group (p < 0.05), and was the highest in bone marrow-derived mesenchymal stem cells and platelet-rich fibrin mixed transplants. Hematoxylin and eosin staining showed that the structure of new bones formed the best

Muscle changes can account for bone loss after botulinum toxin injection.

PubMed

Manske, Sarah L; Boyd, Steven K; Zernicke, Ronald F

2010-12-01

Studies to date have assumed that botulinum toxin type A (BTX) affects bone indirectly, through its action on muscle. We hypothesized that BTX has no discernable effect on bone morphometry, independent of its effect on muscle. Therefore, we investigated whether BTX had an additional effect on bone when combined with tenotomy compared to tenotomy in isolation. Female BALB/c mice (n = 73) underwent one of the following procedures in the left leg: BTX injection and Achilles tenotomy (BTX-TEN), BTX injection and sham surgery (BTX-sham), Achilles tenotomy (TEN), or sham surgery (sham). BTX groups were injected with 20 μL of BTX (1 U/100 g) in the posterior lower hindlimb. At 4 weeks, muscle cross-sectional area (MCSA) and tibial bone morphometry were assessed using micro-CT. Each treatment, other than sham, resulted in significant muscle and bone loss (P < 0.05). BTX-TEN experienced the greatest muscle loss (23-45% lower than other groups) and bone loss (20-30% lower bone volume fraction than other groups). BTX-sham had significantly lower MCSA and bone volume fraction than TEN and sham. After adjusting for differences in MCSA, there were no significant between-group differences in bone properties. We found that BTX injection resulted in more adverse muscle and bone effects than tenotomy and that effects were amplified when the procedures were combined. However, between-group differences in bone could be accounted for by MCSA. We conclude that any independent effect of BTX on bone morphometry is likely small or negligible compared with the effect on muscle.

The effective elastic properties of human trabecular bone may be approximated using micro-finite element analyses of embedded volume elements.

PubMed

Daszkiewicz, Karol; Maquer, Ghislain; Zysset, Philippe K

2017-06-01

Boundary conditions (BCs) and sample size affect the measured elastic properties of cancellous bone. Samples too small to be representative appear stiffer under kinematic uniform BCs (KUBCs) than under periodicity-compatible mixed uniform BCs (PMUBCs). To avoid those effects, we propose to determine the effective properties of trabecular bone using an embedded configuration. Cubic samples of various sizes (2.63, 5.29, 7.96, 10.58 and 15.87 mm) were cropped from [Formula: see text] scans of femoral heads and vertebral bodies. They were converted into [Formula: see text] models and their stiffness tensor was established via six uniaxial and shear load cases. PMUBCs- and KUBCs-based tensors were determined for each sample. "In situ" stiffness tensors were also evaluated for the embedded configuration, i.e. when the loads were transmitted to the samples via a layer of trabecular bone. The Zysset-Curnier model accounting for bone volume fraction and fabric anisotropy was fitted to those stiffness tensors, and model parameters [Formula: see text] (Poisson's ratio) [Formula: see text] and [Formula: see text] (elastic and shear moduli) were compared between sizes. BCs and sample size had little impact on [Formula: see text]. However, KUBCs- and PMUBCs-based [Formula: see text] and [Formula: see text], respectively, decreased and increased with growing size, though convergence was not reached even for our largest samples. Both BCs produced upper and lower bounds for the in situ values that were almost constant across samples dimensions, thus appearing as an approximation of the effective properties. PMUBCs seem also appropriate for mimicking the trabecular core, but they still underestimate its elastic properties (especially in shear) even for nearly orthotropic samples.

Biological effect of hydrolyzed collagen on bone metabolism.

PubMed

Daneault, Audrey; Prawitt, Janne; Fabien Soulé, Véronique; Coxam, Véronique; Wittrant, Yohann

2017-06-13

Osteoporosis is a chronic and asymptomatic disease characterized by low bone mass and skeletal microarchitectural deterioration, increased risk of fracture, and associated comorbidities most prevalent in the elderly. Due to an increasingly aging population, osteoporosis has become a major health issue requiring innovative disease management. Proteins are important for bone by providing building blocks and by exerting specific regulatory function. This is why adequate protein intake plays a considerable role in both bone development and bone maintenance. More specifically, since an increase in the overall metabolism of collagen can lead to severe dysfunctions and a more fragile bone matrix and because orally administered collagen can be digested in the gut, cross the intestinal barrier, enter the circulation, and become available for metabolic processes in the target tissues, one may speculate that a collagen-enriched diet provides benefits for the skeleton. Collagen-derived products such as gelatin or hydrolyzed collagen (HC) are well acknowledged for their safety from a nutritional point of view; however, what is their impact on bone biology? In this manuscript, we critically review the evidence from literature for an effect of HC on bone tissues in order to determine whether HC may represent a relevant alternative in the design of future nutritional approaches to manage osteoporosis prevention.

Molecular Abnormalities Underlying Bone Fragility in Chronic Kidney Disease

PubMed Central

Iwasaki, Yoshiko; Kazama, Junichiro James

2017-01-01

Prevention of bone fractures is one goal of therapy for patients with chronic kidney disease-mineral and bone disorder (CKD-MBD), as indicated by the Kidney Disease: Improving Global Outcomes guidelines. CKD patients, including those on hemodialysis, are at higher risk for fractures and fracture-related death compared to people with normal kidney function. However, few clinicians focus on this issue as it is very difficult to estimate bone fragility. Additionally, uremia-related bone fragility has a more complicated pathological process compared to osteoporosis. There are many uremia-associated factors that contribute to bone fragility, including severe secondary hyperparathyroidism, skeletal resistance to parathyroid hormone, and bone mineralization disorders. Uremia also aggravates bone volume loss, disarranges microarchitecture, and increases the deterioration of material properties of bone through abnormal bone cells or excess oxidative stress. In this review, we outline the prevalence of fractures, the interaction of CKD-MBD with osteoporosis in CKD patients, and discuss possible factors that exacerbate the mechanical properties of bone. PMID:28421193

Alveolar ridge preservation with deproteinized bovine bone graft and collagen membrane and delayed implants.

PubMed

Pang, Chaoyuan; Ding, Yuxiang; Zhou, Hongzhi; Qin, Ruifeng; Hou, Rui; Zhang, Guoliang; Hu, Kaijin

2014-09-01

To evaluate clinically and radiographically an alveolar ridge, preservation technique with deproteinized bovine bone graft and absorbable collagen membrane and then restoration with delayed implants were done. The study included 30 patients. The trial group's sockets were filled with deproteinized bovine bone graft (Bio-Oss) and covered with absorbable collagen membrane (Bio-Gide). The control group's sockets healed without any treatment. Panoramic radiograph and computed tomography were taken immediately after graft and 3 and 6 months later to evaluate the height, width, and volume change of the alveolar ridge bone. Dental implants were inserted in all sockets at 6 months, and osseointegration condition was evaluated in the following 12 months. All sockets healed uneventfully. In the trial group, the mean (SD) height reduction of the alveolar ridge bone was 1.05 (0.24) mm at 3 months and 1.54 (0.25) mm at 6 months. The width reduction was 1.11 (0.13) mm at 3 months and 1.84 (0.35) mm at 6 months. Bone volume reduction was 193.79 (21.47) mm at 3 months and 262.06 (33.08) mm at 6 months. At the same trend, in the control group, the bone height reduction was 2.12 (0.15) mm at 3 months and 3.26 (0.29) mm at 6 months. The width reduction was 2.72 (0.19) mm at 3 months and 3.56 (0.28) mm at 6 months. Bone volume reduction was 252.19 (37.21) mm at 3 months and 342.32 (36.41) mm at 6 months. There was a significant difference in alveolar ridge bone height, width, and volume reduction in the 2 groups. The osseointegration condition had no significant difference between the 2 groups. This study suggested that the deproteinized bovine bone graft and absorbable collagen membrane were beneficial to preserve the alveolar ridge bone and had no influence on the osseointegration of delayed implant.

A structural approach in the study of bones: fossil and burnt bones at nanosize scale

NASA Astrophysics Data System (ADS)

Piga, Giampaolo; Baró, Maria Dolors; Escobal, Irati Golvano; Gonçalves, David; Makhoul, Calil; Amarante, Ana; Malgosa, Assumpció; Enzo, Stefano; Garroni, Sebastiano

2016-12-01

We review the different factors affecting significantly mineral structure and composition of bones. Particularly, it is assessed that micro-nanostructural and chemical properties of skeleton bones change drastically during burning; the micro- and nanostructural changes attending those phases manifest themselves, amongst others, in observable alterations to the bones colour, morphology, microstructure, mechanical strength and crystallinity. Intense changes involving the structure and chemical composition of bones also occur during the fossilization process. Bioapatite material is contaminated by an heavy fluorination process which, on a long-time scale reduces sensibly the volume of the original unit cell, mainly the a-axis of the hexagonal P63/m space group. Moreover, the bioapatite suffers to a varying degree of extent by phase contamination from the nearby environment, to the point that rarely a fluorapatite single phase may be found in fossil bones here examined. TEM images supply precise and localized information, on apatite crystal shape and dimension, and on different processes that occur during thermal processes or fossilization of ancient bone, complementary to that given by X-ray diffraction and Attenuated Total Reflection Infrared spectroscopy. We are presenting a synthesis of XRD, ATR-IR and TEM results on the nanostructure of various modern, burned and palaeontological bones.

Autologous implantation of BMP2-expressing dermal fibroblasts to improve bone mineral density and architecture in rabbit long bones.

PubMed

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.

QUANTITATIVE PLUTONIUM MICRODISTRIBUTION IN BONE TISSUE OF VERTEBRA FROM A MAYAK WORKER

PubMed Central

Lyovkina, Yekaterina V.; Miller, Scott C.; Romanov, Sergey A.; Krahenbuhl, Melinda P.; Belosokhov, Maxim V.

2010-01-01

The purpose was to obtain quantitative data on plutonium microdistribution in different structural elements of human bone tissue for local dose assessment and dosimetric models validation. A sample of the thoracic vertebra was obtained from a former Mayak worker with a rather high plutonium burden. Additional information was obtained on occupational and exposure history, medical history, and measured plutonium content in organs. Plutonium was detected in bone sections from its fission tracks in polycarbonate film using neutron-induced autoradiography. Quantitative analysis of randomly selected microscopic fields on one of the autoradiographs was performed. Data included fission fragment tracks in different bone tissue and surface areas. Quantitative information on plutonium microdistribution in human bone tissue was obtained for the first time. From these data, quantitative relationship of plutonium decays in bone volume to decays on bone surface in cortical and trabecular fractions were defined as 2.0 and 0.4, correspondingly. The measured quantitative relationship of decays in bone volume to decays on bone surface does not coincide with recommended models for the cortical bone fraction by the International Commission on Radiological Protection. Biokinetic model parameters of extrapulmonary compartments might need to be adjusted after expansion of the data set on quantitative plutonium microdistribution in other bone types in human as well as other cases with different exposure patterns and types of plutonium. PMID:20838087

Bone tissue engineering: state of the art and future trends.

PubMed

Salgado, António J; Coutinho, Olga P; Reis, Rui L

2004-08-09

Although several major progresses have been introduced in the field of bone regenerative medicine during the years, current therapies, such as bone grafts, still have many limitations. Moreover, and in spite of the fact that material science technology has resulted in clear improvements in the field of bone substitution medicine, no adequate bone substitute has been developed and hence large bone defects/injuries still represent a major challenge for orthopaedic and reconstructive surgeons. It is in this context that TE has been emerging as a valid approach to the current therapies for bone regeneration/substitution. In contrast to classic biomaterial approach, TE is based on the understanding of tissue formation and regeneration, and aims to induce new functional tissues, rather than just to implant new spare parts. The present review pretends to give an exhaustive overview on all components needed for making bone tissue engineering a successful therapy. It begins by giving the reader a brief background on bone biology, followed by an exhaustive description of all the relevant components on bone TE, going from materials to scaffolds and from cells to tissue engineering strategies, that will lead to "engineered" bone. Scaffolds processed by using a methodology based on extrusion with blowing agents.

Short-term physical activity intervention decreases femoral bone marrow adipose tissue in young children: a pilot study

PubMed Central

Casazza, K; Hanks, LJ; Hidalgo, B; Hu, HH; Affuso, O

2011-01-01

Mechanical stimulation is necessary for maximization of geometrical properties of bone mineralization contributing to long-term strength. The amount of mineralization in bones has been reciprocally related to volume of bone marrow adipose tissue and this relationship is suggested to be an independent predictor of fracture. Physical activity represents an extrinsic factor that impacts both mineralization and marrow volume exerting permissive capacity of the growing skeleton to achieve its full genetic potential. Because geometry- and shape-determining processes primarily manifest during the linear growth period, the accelerated structural changes accompanying early childhood (ages 3 to 6 y) may have profound impact on lifelong bone health. The objective of this pilot study was to determine if a short-term physical activity intervention in young children would result in augmentation of geometric properties of bone. Three days per week the intervention group (n=10) participated in 30 minutes of moderate intensity physical activity, such as jumping, hopping and running, and stretching activities, whereas controls (n=10) underwent usual activities during the 10-week intervention period. Femoral bone marrow adipose tissue volume and total body composition were assessed by magnetic resonance imaging and dual-energy X-ray absorptiometry, respectively, at baseline and after ten weeks. Although after 10-weeks, intergroup differences were not observed, a significant decrease in femoral marrow adipose tissue volume was observed in those participating in physical activity intervention. Our findings suggest physical activity may improve bone quality via antagonistic effects on femoral bone marrow adipose tissue and possibly long-term agonistic effects on bone mineralization. PMID:21939791

Altered thermogenesis and impaired bone remodeling in Misty mice.

PubMed

Motyl, Katherine J; Bishop, Kathleen A; DeMambro, Victoria E; Bornstein, Sheila A; Le, Phuong; Kawai, Masanobu; Lotinun, Sutada; Horowitz, Mark C; Baron, Roland; Bouxsein, Mary L; Rosen, Clifford J

2013-09-01

Fat mass may be modulated by the number of brown-like adipocytes in white adipose tissue (WAT) in humans and rodents. Bone remodeling is dependent on systemic energy metabolism and, with age, bone remodeling becomes uncoupled and brown adipose tissue (BAT) function declines. To test the interaction between BAT and bone, we employed Misty (m/m) mice, which were reported be deficient in BAT. We found that Misty mice have accelerated age-related trabecular bone loss and impaired brown fat function (including reduced temperature, lower expression of Pgc1a, and less sympathetic innervation compared to wild-type (+/ +)). Despite reduced BAT function, Misty mice had normal core body temperature, suggesting heat is produced from other sources. Indeed, upon acute cold exposure (4°C for 6 hours), inguinal WAT from Misty mice compensated for BAT dysfunction by increasing expression of Acadl, Pgc1a, Dio2, and other thermogenic genes. Interestingly, acute cold exposure also decreased Runx2 and increased Rankl expression in Misty bone, but only Runx2 was decreased in wild-type. Browning of WAT is under the control of the sympathetic nervous system (SNS) and, if present at room temperature, could impact bone metabolism. To test whether SNS activity could be responsible for accelerated trabecular bone loss, we treated wild-type and Misty mice with the β-blocker, propranolol. As predicted, propranolol slowed trabecular bone volume/total volume (BV/TV) loss in the distal femur of Misty mice without affecting wild-type. Finally, the Misty mutation (a truncation of DOCK7) also has a significant cell-autonomous role. We found DOCK7 expression in whole bone and osteoblasts. Primary osteoblast differentiation from Misty calvaria was impaired, demonstrating a novel role for DOCK7 in bone remodeling. Despite the multifaceted effects of the Misty mutation, we have shown that impaired brown fat function leads to altered SNS activity and bone loss, and for the first time that cold

Effect of epimedium pubescen flavonoid on bone mineral status and bone turnover in male rats chronically exposed to cigarette smoke.

PubMed

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.

The quantitative assessment of peri-implant bone responses using histomorphometry and micro-computed tomography.

PubMed

Schouten, Corinne; Meijer, Gert J; van den Beucken, Jeroen J J P; Spauwen, Paul H M; Jansen, John A

2009-09-01

In the present study, the effects of implant design and surface properties on peri-implant bone response were evaluated with both conventional histomorphometry and micro-computed tomography (micro-CT), using two geometrically different dental implants (Screw type, St; Push-in, Pi) either or not surface-modified (non-coated, CaP-coated, or CaP-coated+TGF-beta1). After 12 weeks of implantation in a goat femoral condyle model, peri-implant bone response was evaluated in three different zones (inner: 0-500 microm; middle: 500-1000 microm; and outer: 1000-1500 microm) around the implant. Results indicated superiority of conventional histomorphometry over micro-CT, as the latter is hampered by deficits in the discrimination at the implant/tissue interface. Beyond this interface, both analysis techniques can be regarded as complementary. Histomorphometrical analysis showed an overall higher bone volume around St compared to Pi implants, but no effects of surface modification were observed. St implants showed lowest bone volumes in the outer zone, whereas inner zones were lowest for Pi implants. These results implicate that for Pi implants bone formation started from two different directions (contact- and distance osteogenesis). For St implants it was concluded that undersized implantation technique and loosening of bone fragments compress the zones for contact and distant osteogenesis, thereby improving bone volume at the interface significantly.

Aromatase Inhibitors and Bone Loss

PubMed Central

PEREZ, EDITH A.; M., Serene; Durling, Frances C.; WEILBAECHER, KATHERINE

2009-01-01

The aromatase inhibitors (AIs) anastrozole (Arimidex), letrozole (Femara), and exemestane (Aromasin) are significantly more effective than the selective estrogen-receptor modulator (SERM) tamoxifen in preventing recurrence in estrogen receptor–positive early breast cancer. Aromatase inhibitors are likely to replace SERMs as first-line adjuvant therapy for many patients. However, AIs are associated with significantly more osteoporotic fractures and greater bone mineral loss. As antiresorptive agents, oral and intravenous bisphosphonates such as alendronate (Fosamax), risedronate (Actonel), ibandronate (Boniva), pamidronate (Aredia), and zoledronic acid (Zometa) have efficacy in preventing postmenopausal osteoporosis, cancer treatment–related bone loss, or skeletal complications of metastatic disease. Clinical practice guidelines recommend baseline and annual follow-up bone density monitoring for all patients initiating AI therapy. Bisphosphonate therapy should be prescribed for patients with osteoporosis (T score < −2.5) and considered on an individual basis for those with osteopenia (T score < −1). Modifiable lifestyle behaviors including adequate calcium and vitamin D intake, weight-bearing exercise, and smoking cessation should be addressed. Adverse events associated with bisphosphonates include gastrointestinal toxicity, renal toxicity, and osteonecrosis of the jaw. These safety concerns should be balanced with the potential of bisphosphonates to minimize or prevent the debilitating effects of AI-associated bone loss in patients with early, hormone receptor–positive breast cancer. PMID:16986348

Different effects on bone strength and cell differentiation in pre pubertal caloric restriction versus hypothalamic suppression✩,✩✩

PubMed Central

Joshi, R.N.; Safadi, F.F.; Barbe, M.F.; Carpio-Cano, Fe Del; Popoff, S.N.; Yingling, V.R.

2013-01-01

Hypothalamic amenorrhea and energy restriction during puberty affect peak bone mass accrual. One hypothesis suggests energy restriction alters hypothalamic function resulting in suppressed estradiol levels leading to bone loss. However, both positive and negative results have been reported regarding energy restriction and bone strength. Therefore, the purpose of this study was to investigate energy restriction and hypothalamic suppression during pubertal onset on bone mechanical strength and the osteogenic capacity of bone marrow-derived cells in two models: female rats treated with gonadotropin releasing hormone antagonists (GnRH-a) or 30% energy restriction. At 23 days of age, female Sprague Dawley rats were assigned to three groups: control group (C, n=10), GnRH-a group (n=10), and Energy Restriction (ER, n=12) group. GnRH-a animals received daily injections for 27 days. The animals in the ER group received 70% of the control animals’ intake. After sacrifice (50 days of age), body weight, uterine and muscle weights were measured. Bone marrow-derived stromal cells were cultured and assayed for proliferation and differentiation into osteoblasts. Outcome measures included bone strength, bone histomorphometry and architecture, serum IGF-1 and osteocalcin. GnRH-a suppressed uterine weight, decreased osteoblast proliferation, bone strength, trabecular bone volume and architecture compared to control. Elevated serum IGF-1 and osteocalcin levels and body weight were found. The ER model had an increase in osteoblast proliferation compared to the GnRH-a group, similar bone strength relative to body weight and increased trabecular bone volume in the lumbar spine compared to control. The ER animals were smaller but had developed bone strength sufficient for their size. In contrast, suppressed estradiol via hypothalamic suppression resulted in bone strength deficits and trabecular bone volume loss. In summary, our results support the hypothesis that during periods of

DNA survival and physical and histological properties of heat-induced alterations in burnt bones.

PubMed

Imaizumi, K; Taniguchi, K; Ogawa, Y

2014-05-01

During forensic casework, it is vital to be able to obtain valuable information from burnt bone fragments to ascertain the identity of the victim. Here, we report the findings of an experimental study on burnt bovine compact bone segments. Compact bones were cut to size and heated in an electric furnace at a temperature range of 100–1,100 °C with 100 °C increments. Heat-induced alterations to the bone color,weight, volume, and density were monitored using gross morphology and micro-focus X-ray computed tomography.We found that the increase in temperature caused the color of the compact bones to change in order of yellow, brown, gray,and white. In contrast to the weight reduction that occurred immediately after burning, we measured no significant reduction in volume even at 600 °C; however, volume reduced drastically once the temperature reached 700 °C. Light microscopic histological observations of burnt bone revealed heat induced alterations such as cracking and separation of the osteons at higher temperatures. In addition to these findings,we sought to examine the survival of DNA in the burnt bones using polymerase chain reaction of mitochondrial DNA. No amplification was found in the specimens burnt at 250 °C or higher, indicating the likely difficulty in testing the DNA of burnt bones from forensic casework. The results of this study will enable an estimation of the burning temperatures of burnt bones found in forensic cases and will provide an important framework with which to interpret data obtained during anthropological testing and DNA typing.

Bone histomorphometry in de novo renal transplant recipients indicates a further decline in bone resorption 1 year posttransplantation.

PubMed

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.

Biomechanics and strain mapping in bone as related to immediately-loaded dental implants

PubMed Central

Du, Jing; Lee, Jihyun; Jang, Andrew; Gu, Allen; Hossaini-Zadeh, Mehran; Prevost, Richard; Curtis, Don; Ho, Sunita

2015-01-01

The effects of alveolar bone socket geometry and bone-implant contact on implant biomechanics, and resulting strain distributions in bone were investigated. Following extraction of lateral incisors on a cadaver mandible, immediate implants were placed and bone-implant contact area, stability and bone strain were measured. In situ biomechanical testing coupled with micro X-ray microscope (μ-XRM) illustrated less stiff bone-implant complexes (701-822 N/mm) compared with bone-periodontal ligament (PDL)-tooth complexes (791-913 N/mm). X-ray tomograms illustrated that the cause of reduced stiffness was due to reduced and limited bone-implant contact. Heterogeneous elemental composition of bone was identified by using energy dispersive X-ray spectroscopy (EDS). The novel aspect of this study was the application of a new experimental mechanics method, that is, digital volume correlation, which allowed mapping of strains in volumes of alveolar bone in contact with a loaded implant. The identified surface and subsurface strain concentrations were a manifestation of load transferred to bone through bone-implant contact based on bone-implant geometry, quality of bone, implant placement, and implant design. 3D strain mapping indicated that strain concentrations are not exclusive to the bone-implant contact regions, but also extend into bone not directly in contact with the implant. The implications of the observed strain concentrations are discussed in the context of mechanobiology. Although a plausible explanation of surgical complications for immediate implant treatment is provided, extrapolation of results is only warranted by future systematic studies on more cadaver specimens and/or in vivo small scale animal models. PMID:26162549

Associations among Endocrine, Inflammatory, and Bone Markers, Body Composition and Physical Activity to Weight Loss Induced Bone Loss

PubMed Central

Labouesse, Marie A.; Gertz, Erik R.; Piccolo, Brian D.; Souza, Elaine C.; Schuster, Gertrud U.; Witbracht, Megan G.; Woodhouse, Leslie R.; Adams, Sean H.; Keim, Nancy L.; Van Loan, Marta D.

2015-01-01

INTRODUCTION Weight loss reduces co-morbidities of obesity, but decreases bone mass. PURPOSE Our aims were to 1) determine if adequate dairy intake attenuates weight loss-induced bone loss; 2) evaluate the associations of endocrine, inflammatory and bone markers, anthropometric and other parameters to bone mineral density and content (BMD, BMC) pre- and post-weight loss; 3) model the contribution of these variables to post weight-loss BMD and BMC METHODS Overweight/obese women (BMI: 28–37 kg/m2) were enrolled in an energy reduced (−500 kcal/d; −2092 kJ/d) diet with adequate dairy (AD: 3–4 servings/d; n=25, 32.2 ± 8.8y) or low dairy (LD: ≤ 1 serving/d; n=26, 31.7 ± 8.4 y). BMD, BMC and body composition were measured by DXA. Bone markers (CTX, PYD, BAP, OC), endocrine (PTH, vitamin D, leptin, adiponectin, ghrelin, amylin, insulin, GLP-1, PAI-1, HOMA) and inflammatory markers (CRP, IL1-β, IL-6, IL-8, TNF-α, cortisol) were measured in serum or plasma. PA was assessed by accelerometry. RESULTS Following weight loss, AD intake resulted in significantly greater (p= 0.004) lumbar spine BMD and serum osteocalcin (p=0.004) concentration compared to LD. Pre- and post- body fat were negatively associated with hip and lumbar spine BMC (r= −0.28, p=0.04 to −0.45, p=0.001). Of note were the significant negative associations among bone markers and IL-1β, TNFα and CRP ranging from r = −0.29 (p=0.04) to r = −0.34 (p=0.01); magnitude of associations did not change with weight loss. Adiponectin was negatively related to change in osteocalcin. Factor analysis resulted in 8 pre- and post-weight loss Factors. Pre-weight loss Factors accounted for 13.7% of the total variance in pre-weight loss hip BMD; post-weight loss Factors explained 19.6% of the total variance in post-weight loss hip BMD. None of the Factors contributed to the variance in lumbar spine BMD. CONCLUSION AD during weight loss resulted in higher lumbar spine BMD and osteocalcin compared to LD

5 CFR 919.900 - Adequate evidence.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Adequate evidence. 919.900 Section 919.900 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS.... Adequate evidence means information sufficient to support the reasonable belief that a particular act or...

5 CFR 919.900 - Adequate evidence.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 5 Administrative Personnel 2 2011-01-01 2011-01-01 false Adequate evidence. 919.900 Section 919.900 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS.... Adequate evidence means information sufficient to support the reasonable belief that a particular act or...

5 CFR 919.900 - Adequate evidence.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 5 Administrative Personnel 2 2014-01-01 2014-01-01 false Adequate evidence. 919.900 Section 919.900 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS.... Adequate evidence means information sufficient to support the reasonable belief that a particular act or...

5 CFR 919.900 - Adequate evidence.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 5 Administrative Personnel 2 2013-01-01 2013-01-01 false Adequate evidence. 919.900 Section 919.900 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS.... Adequate evidence means information sufficient to support the reasonable belief that a particular act or...

5 CFR 919.900 - Adequate evidence.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 5 Administrative Personnel 2 2012-01-01 2012-01-01 false Adequate evidence. 919.900 Section 919.900 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS.... Adequate evidence means information sufficient to support the reasonable belief that a particular act or...

The dynamic volume changes of polymerising polymethyl methacrylate bone cement.

PubMed

Muller, Scott D; Green, Sarah M; McCaskie, Andrew W

2002-12-01

The Swedish hip register found an increased risk of early revision of vacuum-mixed cemented total hip replacements. The influence of cement mixing technique on the dynamic volume change in polymerising PMMA is not well understood and may be relevant to this observation. Applying Archimedes' principle, we have investigated the dynamic volume changes in polymerising cement and determined the influence of mixing technique. All specimens showed an overall volume reduction: hand-mixed 3.4% and vacuum-mixed 6.0%. Regression analysis of sectional porosity and volume reduction showed a highly significant relationship. Hand-mixed porous cement showed a transient volume increase before solidification. However, vacuum-mixed cement showed a progressive volume reduction throughout polymerisation. Transient expansion of porous cement occurs at the critical time of micro-interlock formation, possibly improving fixation. Conversely, progressive volume reduction of vacuum-mixed cement throughout the formation of interlock may damage fixation. Stable fixation of vacuum-mixed cement may depend on additional techniques to offset the altered volumetric behaviour of vacuum-mixed cement.

Influence of peri-implant artifacts on bone morphometric analysis with micro-computed tomography.

PubMed

Song, Jin Wook; Cha, Jung Yul; Bechtold, Till Edward; Park, Young Chel

2013-01-01

To determine the optimal dilation pixel size distance from the mini-implant interface needed to compensate for the metal artifact on micro-computed tomography (micro-CT) for bone morphometric analysis. A total of 72 self-drilling mini-implants were placed into the buccal alveolar bone of six male beagle dogs. After 12 weeks of orthodontic loading, specimens were harvested and scanned with micro-CT (Skyscan 1076) at a resolution of 9 μm. Using the reload plug-in and dilation procedure of CTAn, the percentage of bone-implant contact (BIC) and bone volume density (BV/TV, bone volume/total volume), respectively, were measured from one to seven pixels from the metal implant surface. Each pixel size of dilation (PSD) were compared with that of a ground histologic section, and the optimal PSD for bone morphometric analysis using micro-CT was determined. BIC values from micro-CT analysis decreased when the PSD increased (P < .05). BIC from micro-CT showed the highest correlation coefficient with BIC from histologic slides when the PSD was 5 to 7 (P < .05), whereas BV/TV from micro-CT showed a very high correlation with BV/TV from histologic slides in all ranges (P < .0001). To measure BIC and BV/TV using micro-CT, at least 5 PSD from the metal implant surface is needed.

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

PubMed

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.

Mechanical design optimization of bioabsorbable fixation devices for bone fractures.

PubMed

Lovald, Scott T; Khraishi, Tariq; Wagner, Jon; Baack, Bret

2009-03-01

Bioabsorbable bone plates can eliminate the necessity for a permanent implant when used to fixate fractures of the human mandible. They are currently not in widespread use because of the low strength of the materials and the requisite large volume of the resulting bone plate. The aim of the current study was to discover a minimally invasive bioabsorbable bone plate design that can provide the same mechanical stability as a standard titanium bone plate. A finite element model of a mandible with a fracture in the body region is subjected to bite loads that are common to patients postsurgery. The model is used first to determine benchmark stress and strain values for a titanium plate. These values are then set as the limits within which the bioabsorbable bone plate must comply. The model is then modified to consider a bone plate made of the polymer poly-L/DL-lactide 70/30. An optimization routine is run to determine the smallest volume of bioabsorbable bone plate that can perform and a titanium bone plate when fixating fractures of this considered type. Two design parameters are varied for the bone plate design during the optimization analysis. The analysis determined that a strut style poly-L-lactide-co-DL-lactide plate of 690 mm2 can provide as much mechanical stability as a similar titanium design structure of 172 mm2. The model has determined a bioabsorbable bone plate design that is as strong as a titanium plate when fixating fractures of the load-bearing mandible. This is an intriguing outcome, considering that the polymer material has only 6% of the stiffness of titanium.

Evaluation of antitumor activity and cardiac toxicity of a bone-targeted ph-sensitive liposomal formulation in a bone metastasis tumor model in mice.

PubMed

Dos Santos Ferreira, Diego; Jesus de Oliveira Pinto, Bruno Luís; Kumar, Vidhya; Cardoso, Valbert Nascimento; Fernandes, Simone Odília; Souza, Cristina Maria; Cassali, Geovanni Dantas; Moore, Anna; Sosnovik, David E; Farrar, Christian T; Leite, Elaine Amaral; Alves, Ricardo José; de Oliveira, Mônica Cristina; Guimarães, Alexander Ramos; Caravan, Peter

2017-07-01

Chemotherapy for bone tumors is a major challenge because of the inability of therapeutics to penetrate dense bone mineral. We hypothesize that a nanostructured formulation with high affinity for bone could deliver drug to the tumor while minimizing off-target toxicity. Here, we evaluated the efficacy and toxicity of a novel bone-targeted, pH-sensitive liposomal formulation containing doxorubicin in an animal model of bone metastasis. Biodistribution studies with the liposome showed good uptake in tumor, but low accumulation of doxorubicin in the heart. Mice treated with the bone-targeted liposome formulation showed a 70% reduction in tumor volume, compared to 35% reduction for free doxorubicin at the same dose. Both cardiac toxicity and overall mortality were significantly lower for animals treated with the bone-targeted liposomes compared to free drug. Bone-targeted, pH-sensitive, doxorubicin containing liposomes represent a promising approach to selectively delivering doxorubicin to bone tumors while minimizing cardiac toxicity. Copyright © 2017 Elsevier Inc. All rights reserved.

Surface structural damage study in cortical bone due to medical drilling.

PubMed

Tavera R, Cesar G; De la Torre-I, Manuel H; Flores-M, Jorge M; Hernandez M, Ma Del Socorro; Mendoza-Santoyo, Fernando; Briones-R, Manuel de J; Sanchez-P, Jorge

2017-05-01

A bone's fracture could be produced by an excessive, repetitive, or sudden load. A regular medical practice to heal it is to fix it in two possible ways: external immobilization, using a ferule, or an internal fixation, using a prosthetic device commonly attached to the bone by means of surgical screws. The bone's volume loss due to this drilling modifies its structure either in the presence or absence of a fracture. To observe the bone's surface behavior caused by the drilling effects, a digital holographic interferometer is used to analyze the displacement surface's variations in nonfractured post-mortem porcine femoral bones. Several nondrilled post-mortem bones are compressed and compared to a set of post-mortem bones with a different number of cortical drillings. During each compression test, a series of digital interferometric holograms were recorded using a high-speed CMOS camera. The results are presented as pseudo 3D mesh displacement maps for comparisons in the physiological range of load (30 and 50 lbs) and beyond (100, 200, and 400 lbs). The high resolution of the optical phase gives a better understanding about the bone's microstructural modifications. Finally, a relationship between compression load and bone volume loss due to the drilling was observed. The results prove that digital holographic interferometry is a viable technique to study the conditions that avoid the surgical screw from loosening in medical procedures of this kind.

LORENZ: a system for planning long-bone fracture reduction

NASA Astrophysics Data System (ADS)

Birkfellner, Wolfgang; Burgstaller, Wolfgang; Wirth, Joachim; Baumann, Bernard; Jacob, Augustinus L.; Bieri, Kurt; Traud, Stefan; Strub, Michael; Regazzoni, Pietro; Messmer, Peter

2003-05-01

Long bone fractures belong to the most common injuries encountered in clinical routine trauma surgery. Preoperative assessment and decision making is usually based on standard 2D radiographs of the injured limb. Taking into account that a 3D - imaging modality such as computed tomography (CT) is not used for diagnosis in clinical routine, we have designed LORENZ, a fracture reduction planning tool based on such standard radiographs. Taking into account the considerable success of so-called image free navigation systems for total knee replacement in orthopaedic surgery, we assume that a similar tool for long bone fracture reposition should have considerable impact on computer-aided trauma surgery in a standard clinical routine setup. The case for long bone fracture reduction is, however, somewhat more complicated since not only scale independent angles indicating biomechanical measures such as varus and valgus are involved. Reduction path planning requires that the individual anatomy and the classification of the fracture is taken into account. In this paper, we present the basic ideas of this planning tool, it's current state, and the methodology chosen. LORENZ takes one or more conventional radiographs of the broken limb as input data. In addition, one or more x-rays of the opposite healthy bone are taken and mirrored if necessary. A most adequate CT model is being selected from a database; currently, this is achieved by using a scale space approach on the digitized x-ray images and comparing standard perspective renderings to these x-rays. After finding a CT-volume with a similar bone, a triangulated surface model is generated, and the surgeon can break the bone and arrange the fragments in 3D according to the x-ray images of the broken bone. Common osteosynthesis plates and implants can be loaded from CAD-datasets and are visualized as well. In addition, LORENZ renders virtual x-ray views of the fracture reduction process. The hybrid surface/voxel rendering

[Nutrition and bone health. Soybean and soy foods, and bone health].

PubMed

Kubota, Megumi; Shimizu, Hirotoshi

2009-10-01

Soybean and various types of soy products, such as natto, tofu, miso, and soy sauce, have long been consumed in Japan. Soybean, a rich source of plant proteins, contains a relatively high amount of calcium as well as being an important source of isoflavones, a group of substances whose chemical structure is similar to that of estrogen. Natto, fermented soybeans, contains vitamin K, which is involved in the activation of osteocalcin. For bone health and osteoporosis prevention in Japanese, it is thus beneficial to consume adequate amounts of soybean and soy products on a daily basis.

Design and properties of 3D scaffolds for bone tissue engineering.

PubMed

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

Predicting Bone Mechanical State During Recovery After Long-Duration Skeletal Unloading Using QCT and Finite Element Modeling

NASA Technical Reports Server (NTRS)

Chang, Katarina L.; Pennline, James A.

2013-01-01

During long-duration missions at the International Space Station, astronauts experience weightlessness leading to skeletal unloading. Unloading causes a lack of a mechanical stimulus that triggers bone cellular units to remove mass from the skeleton. A mathematical system of the cellular dynamics predicts theoretical changes to volume fractions and ash fraction in response to temporal variations in skeletal loading. No current model uses image technology to gather information about a skeletal site s initial properties to calculate bone remodeling changes and then to compare predicted bone strengths with the initial strength. The goal of this study is to use quantitative computed tomography (QCT) in conjunction with a computational model of the bone remodeling process to establish initial bone properties to predict changes in bone mechanics during bone loss and recovery with finite element (FE) modeling. Input parameters for the remodeling model include bone volume fraction and ash fraction, which are both computed from the QCT images. A non-destructive approach to measure ash fraction is also derived. Voxel-based finite element models (FEM) created from QCTs provide initial evaluation of bone strength. Bone volume fraction and ash fraction outputs from the computational model predict changes to the elastic modulus of bone via a two-parameter equation. The modulus captures the effect of bone remodeling and functions as the key to evaluate of changes in strength. Application of this time-dependent modulus to FEMs and composite beam theory enables an assessment of bone mechanics during recovery. Prediction of bone strength is not only important for astronauts, but is also pertinent to millions of patients with osteoporosis and low bone density.

Rapid and automated processing of bone marrow grafts without Ficoll density gradient for transplantation of cryopreserved autologous or ABO-incompatible allogeneic bone marrow.

PubMed

Schanz, U; Gmür, J

1992-12-01

The growing number of BMTs has increased interest in safe and standardized in vitro bone marrow processing techniques. We describe our experience with a rapid automated method for the isolation of mononuclear cells (MNC) from large volumes of bone marrow using a Fenwal CS-3000 cell separator without employing density gradient materials. Forty bone marrow harvests with a mean volume of 1650 +/- 307 ml were processed. A mean of 75 +/- 34% (50 percentile range 54-94%) of the original MNCs were recovered in a volume of 200 ml with only 4 +/- 2% of the starting red blood cells (RBC). Removal of granulocytes, immature myeloid precursors and platelets proved to be sufficient to permit safe cryopreservation and successful autologous BMT (n = 25). Allogeneic BMT (n = 14, including three major ABO-incompatible) could be performed without additional manipulation. In both groups of patients timely and stable engraftment comparable to historical controls receiving Ficoll gradient processed autologous (n = 17) or unprocessed allogeneic BMT (n = 54) was observed. Moreover, 70 +/- 14% of the RBC could be recovered from the grafts. They were used for autologous RBC support of donors, rendering unnecessary autologous blood pre-donations.

Glucocorticoid-induced bone loss can be reversed by the actions of PTH and Risedronate on different pathways for bone formation and mineralization

PubMed Central

Yao, Wei; Cheng, Zhiqiang; Pham, Aaron; Busse, Cheryl; Zimmermann, Elizabeth A.; Ritchie, Robert O.; Lane, Nancy E.

2008-01-01

Glucocorticoid (GC) excess decreases bone mineralization and microarchitecture and lead to reduced bone strength. Both anabolic (PTH) and anti-resorptive agents are used to prevent and treat GC-induced bone loss, yet these bone active agents alter bone turnover by very different mechanisms. Our study objective was to determine how PTH and risedronate (Ris) alter bone quality following GC excess. Five-month-old Swiss-Webster male mice were treated with the glucocorticoid (GC) prednisolone (5 mg/kg 60-day slow-release pellet) or placebo (PL)]. At day 28−56, two groups of GC-treated animals had either PTH (5μg/kg, 5x/wk) or Ris (5μg/kg, 5x/wk) intervention. Bone quality and quantity measurements include x-ray tomography microscopy (XTM) for the degree of bone mineralization (DBM), microCT for bone microarchitecture, compression testing for trabecular bone strength, biochemistry and histomorphometry for bone turnover. In addition, real-time PCR and immunohistochemistry were performed to monitor the expression of several key genes regulating Wnt signaling (bone formation) and mineralization. Results Compared to the placebo treated mice, GC treatment decreased trabecular bone volume (BV/TV) and serum osteocalcin, but increased serum CTX and osteoclast surface with a peak at day 28. GC+PTH increased and GC+Ris restored BV/TV to the PL levels after a 28 day treatment period. Average DBM was lowered after GC treatment (−27%), and it was restored to PL level with GC+Ris and GC+PTH. At day 56, RT-PCR revealed that continuous exposure to GC and GC+PTH increased, while GC+Ris decreased the expression of genes that inhibit bone mineralization (Dmp1 and Phex), compared to the PL group. Wnt signaling antagonists Dkk1, Sost and Wif1 were up-regulated by GC treatment but were down-regulated after GC+PTH treatment. Immunohistochemistry of bone sections found GC increased N terminal dmp-1 while PTH treatment increased both N and C terminal dmp-1 staining around osteocytes

The anisotropic Hooke's law for cancellous bone and wood.

PubMed

Yang, G; Kabel, J; van Rietbergen, B; Odgaard, A; Huiskes, R; Cowin, S C

A method of data analysis for a set of elastic constant measurements is applied to data bases for wood and cancellous bone. For these materials the identification of the type of elastic symmetry is complicated by the variable composition of the material. The data analysis method permits the identification of the type of elastic symmetry to be accomplished independent of the examination of the variable composition. This method of analysis may be applied to any set of elastic constant measurements, but is illustrated here by application to hardwoods and softwoods, and to an extraordinary data base of cancellous bone elastic constants. The solid volume fraction or bulk density is the compositional variable for the elastic constants of these natural materials. The final results are the solid volume fraction dependent orthotropic Hooke's law for cancellous bone and a bulk density dependent one for hardwoods and softwoods.

Healing bone lesion defects using injectable CaSO4 /CaPO4 -TCP bone graft substitute compared to cancellous allograft bone chips in a canine model.

PubMed

Hall, Deborah J; Turner, Thomas M; Urban, Robert M

2018-04-16

CaSO 4 /CaPO 4 -TCP bone graft substitute has been shown to be effective for treatment of bone lesion defects, but its mechanical, histological, and radiographic characteristics have not been studied in direct comparison with a conventional treatment such as cancellous allograft bone. Thirteen canines had a critical-size axial defect created bilaterally into the proximal humerus. CaSO 4 /CaPO 4 -TCP bone graft substitute (PRO-DENSE™, Wright Medical Technology) was injected into the defect in one humerus, and an equal volume of freeze-dried cancellous allograft bone chips was placed in the contralateral defect. The area fraction of new bone, residual graft, and fibrous tissue and the compressive strength and elastic modulus of bone within the defects were determined after 6, 13, or 26 weeks and correlated with radiographic changes. The data were analyzed using Friedman and Mann-Whitney tests. There was more bone in defects treated with the CaSO 4 /CaPO 4 -TCP bone graft substitute compared to defects treated with cancellous bone allograft at all three time points, and the difference at 13 weeks was significant (p = 0.025). The new bone was significantly stronger and stiffer in defects treated with the CaSO 4 /CaPO 4 -TCP bone graft substitute compared to defects treated with cancellous bone allograft at 13 (p = 0.046) and 26 weeks (p = 0.025). At 26 weeks, all defects treated with CaSO 4 /CaPO 4 -TCP bone graft substitute demonstrated complete healing with new bone, whereas healing was incomplete in all defects treated with cancellous allograft chips. The CaSO 4 /CaPO 4 -TCP bone graft substitute could provide faster and significantly stronger healing of bone lesions compared to the conventional treatment using freeze-dried cancellous allograft bone. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 Wiley Periodicals, Inc.

Chitosan based nanofibers in bone tissue engineering.

PubMed

Balagangadharan, K; Dhivya, S; Selvamurugan, N

2017-11-01

Bone tissue engineering involves biomaterials, cells and regulatory factors to make biosynthetic bone grafts with efficient mineralization for regeneration of fractured or damaged bones. Out of all the techniques available for scaffold preparation, electrospinning is given priority as it can fabricate nanostructures. Also, electrospun nanofibers possess unique properties such as the high surface area to volume ratio, porosity, stability, permeability and morphological similarity to that of extra cellular matrix. Chitosan (CS) has a significant edge over other materials and as a graft material, CS can be used alone or in combination with other materials in the form of nanofibers to provide the structural and biochemical cues for acceleration of bone regeneration. Hence, this review was aimed to provide a detailed study available on CS and its composites prepared as nanofibers, and their associated properties found suitable for bone tissue engineering. Copyright © 2016 Elsevier B.V. All rights reserved.

Bone regeneration assessment by optical coherence tomography and MicroCT synchrotron radiation

NASA Astrophysics Data System (ADS)

Negrutiu, Meda L.; Sinescu, Cosmin; Canjau, Silvana; Manescu, Adrian; Topalá, Florin I.; Hoinoiu, Bogdan; Romînu, Mihai; Márcáuteanu, Corina; Duma, Virgil; Bradu, Adrian; Podoleanu, Adrian G.

2013-06-01

Bone grafting is a commonly performed surgical procedure to augment bone regeneration in a variety of orthopaedic and maxillofacial procedures, with autologous bone being considered as the "gold standard" bone-grafting material, as it combines all properties required in a bone-graft material: osteoinduction (bone morphogenetic proteins - BMPs - and other growth factors), osteogenesis (osteoprogenitor cells) and osteoconduction (scaffold). The problematic elements of bone regenerative materials are represented by their quality control methods, the adjustment of the initial bone regenerative material, the monitoring (noninvasive, if possible) during their osteoconduction and osteointegration period and biomedical evaluation of the new regenerated bone. One of the research directions was the interface investigation of the regenerative bone materials and their behavior at different time periods on the normal femoral rat bone. 12 rat femurs were used for this investigation. In each ones a 1 mm diameter hole were drilled and a bone grafting material was inserted in the artificial defect. The femurs were removed after one, three and six months. The defects repaired by bone grafting material were evaluated by optical coherence tomography working in Time Domain Mode at 1300 nm. Three dimensional reconstructions of the interfaces were generated. The validations of the results were evaluated by microCT. Synchrotron Radiation allows achieving high spatial resolution images to be generated with high signal-to-noise ratio. In addition, Synchrotron Radiation allows acquisition of volumes at different energies and volume subtraction to enhance contrast. Evaluation of the bone grafting material/bone interface with noninvasive methods such as optical coherence tomography could act as a valuable procedure that can be use in the future in the usual clinical techniques. The results were confirmed by microCT. Optical coherence tomography can be performed in vivo and can provide a

2 CFR 180.900 - Adequate evidence.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 2 Grants and Agreements 1 2014-01-01 2014-01-01 false Adequate evidence. 180.900 Section 180.900 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements OFFICE OF.... Adequate evidence means information sufficient to support the reasonable belief that a particular act or...

2 CFR 180.900 - Adequate evidence.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 2 Grants and Agreements 1 2011-01-01 2011-01-01 false Adequate evidence. 180.900 Section 180.900 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements OFFICE OF.... Adequate evidence means information sufficient to support the reasonable belief that a particular act or...

Stereological determination of the volume of the rat hemimandible tissues.

PubMed

Silva, M A; Merzel, J

2001-07-01

Rodent incisors are useful models to study the development and behavior of dental and periodontal tissues. Some studies require three-dimensional reconstructions of the tooth but none of the described methods yield actual volumetric data. Unlike the rat lower incisors the hemimandible can be easily isolated and its volume was determined by Cavalieri's geometrical principle. This method associated with point-counting volumetry was used to calculate the volume of the structures found in that bone mainly those related to the lower incisor. For 172 g male rats the mean volume of the hemimandible was 182.7 mm(3), statistically not different from 184.9 mm(3) the mean volume of the same hemimandibles determined by Archimedes' principle. The coefficients of error (CE) of Cavalieri's estimates for the hemimandible, incisor as a whole (the tooth itself, odontogenic region and periodontium) and bone tissue were less than 0.04. For the incisor individual tissues the CEs were usually above 0.05, however their calculated volumes are probably not different from the actual ones. The data for incisors and their periodontal tissues and for bone, because of continuous growth of these structures, are meaningful only for rats of the same gender, strain and weight range. Copyright 2001 Wiley-Liss, Inc.