Dairy Food Intake Is Not Associated with Measures of Bone Microarchitecture in Men and Women: The Framingham Osteoporosis Study.

Previous studies reported that dairy foods are associated with higher areal bone mineral density (BMD) in older adults. However, data on bone strength and bone microarchitecture are lacking. We determined the association of dairy food intake (milk, yogurt, cheese, milk + yogurt, and milk + yogurt + cheese, servings/week) with high resolution peripheral quantitative computed tomography (HR-pQCT) measures of bone (failure load, cortical BMD, cortical thickness, trabecular BMD, and trabecular number). This cross-sectional study included participants with diet from a food frequency questionnaire (in 2005-2008 and/or 1998-2001) and measurements of cortical and trabecular BMD and microarchitecture at the distal tibia and radius (from HR-pQCT in 2012-2015). Sex-specific multivariable linear regression estimated the association of dairy food intake (energy adjusted) with each bone measure adjusting for covariates. Mean age was 64 (SD 8) years and total milk + yogurt + cheese intake was 10.0 (SD 6.6) and 10.6 (6.4) servings/week in men and women, respectively. No significant associations were observed for any of the dairy foods and bone microarchitecture measures except for cheese intake, which was inversely associated with cortical BMD at the radius (p = 0.001) and tibia (p = 0.002) in women alone. In this cohort of primarily healthy older men and women, dairy intake was not associated with bone microarchitecture. The findings related to cheese intake and bone microarchitecture in women warrant further investigation.

Global and Spatial Compartmental Interrelationships of Bone Density, Microstructure, Geometry and Biomechanics in the Distal Radius in a Colles' Fracture Study Using HR-pQCT.

Background: Bone parameters derived from HR-pQCT have been investigated on a parameter-by-parameter basis for different clinical conditions. However, little is known regarding the interrelationships of bone parameters and the spatial distribution of these interrelationships. In this work: 1) we investigate compartmental interrelationships of bone parameters; 2) assess the spatial distribution of interrelationships of bone parameters; and 3) compare interrelationships of bone parameters between postmenopausal women with and without a recent Colles' fracture. Methods: Images from the unaffected radius in fracture cases (n=84), and from the non-dominant radius of controls (n=98) were obtained using HR-pQCT. Trabecular voxel-based maps of local bone volume fraction (L.Tb.BV/TV), homogenized volumetric bone mineral density (H.Tb.BMD), homogenized µFEA-derived strain energy density (H.Tb.SED), and homogenized inter-trabecular distances (H.Tb.1/N) were generated; as well as surface-based maps of apparent cortical bone thickness (Surf.app.Ct.Th), porosity-weighted cortical bone thickness (Surf.Ct.SIT), mean cortical BMD (Surf.Ct.BMD), and mean cortical SED (Surf.Ct.SED). Anatomical correspondences across the parametric maps in the study were established via spatial normalization to a common template. Mean values of the parametric maps before spatial normalization were used to assess compartmental Spearman's rank partial correlations of bone parameters (e.g., between H.Tb.BMD and L.Tb.BV/TV or between Surf.Ct.BMD and Surf.app.Ct.Th). Spearman's rank partial correlations were also assessed for each voxel and vertex of the spatially normalized parametric maps, thus generating maps of Spearman's rank partial correlation coefficients. Correlations were performed independently within each group, and compared between groups using the Fisher's Z transformation. Results: All within-group global trabecular and cortical Spearman's rank partial correlations were significant; and the correlations of H.Tb.BMD-L.Tb.BV/TV, H.Tb.BMD-H.Tb.1/N, L.Tb.BV/TV-H.Tb.1/N, Surf.Ct.BMD-Surf.Ct.SED and Surf.Ct.SIT-Surf.Ct.SED were significantly different between controls and fracture cases. The spatial analyses revealed significant heterogeneous voxel- and surface-based correlation coefficient maps across the distal radius for both groups; and the correlation maps of H.Tb.BMD-L.Tb.BV/TV, H.Tb.BMD-H.Tb.1/N, L.Tb.BV/TV-H.Tb.1/N, H.Tb.1/N-H.Tb.SED and Surf.app.Ct.Th - Surf.Ct.SIT yielded small clusters of significant correlation differences between groups. Discussion: The heterogeneous spatial distribution of interrelationships of bone parameters assessing density, microstructure, geometry and biomechanics, along with their global and local differences between controls and fracture cases, may help us further understand different bone mechanisms of bone fracture.

A prospective case-control pilot study to evaluate bone microarchitecture in children and teenagers on long-term parenteral nutrition using HR-pQCT.

Long-term parenteral nutrition (PN) may induce bone complications. Tridimensional bone imaging techniques such as high-resolution peripheral quantitative computed tomography (HR-pQCT) allow the assessment of both compartmental volumetric densities and microarchitecture. Our aim was to evaluate these parameters in children and teenagers receiving long-term PN. This cross-sectional, case-control study included children older than 9 years undergoing PN for at least 2 years. They were age-, gender- and puberty-matched with healthy controls (1:2). Evaluation included biological assessment of bone metabolism (serum calcium, phosphate, and albumin; urinary calcium and creatinine; 25-OH vitamin D, osteocalcin and PTH), dual X-ray absorptiometry (DXA) and HR-pQCT at the ultradistal tibia and radius. Results are presented as median [range]. Eleven patients (3 girls) with a median age of 16 [9-19] years were included. Bone parameters assessed by HR-pQCT at the ultradistal radius and tibia were similar in patients and controls. Parathyroid hormone (PTH) levels were higher (14 [7-115] vs 16 [12-27]) and osteocalcin levels were lower (44 [15-65] vs 65 [38-142]) in patients than in controls, although within the normal range. Conclusions: there were no differences for compartmental bone densities and microarchitecture in patients undergoing chronic PN. Further longitudinal studies are required to confirm these quite reassuring preliminary results.

Chitosan/gelatin/platelet gel enriched by a combination of hydroxyapatite and beta-tricalcium phosphate in healing of a radial bone defect model in rat.

This study compared the regeneration potentials of the hydroxyapatite (HA) and beta-tricalcium phosphate (ß-TCP) alone or in combination with a HA:TCP ratio of 30:70 in the critical-sized radial bone defects of rats. Bilateral 60 radial bone defects created were randomly divided into six equal groups (n=10 defects/group) including autograft, untreated or defect, chitosan-gelatin-platelet gel (CGP), CGP-HA, CGP-TCP and CGP-HA/TCP. The defects were evaluated by radiography, morphology, histopathology, histomorphometry, CT scan, scanning electron microscopy and biomechanical testing after eight weeks. Compared with the untreated and CGP-HA groups, the CGP and CGP-HA/TCP groups showed significantly higher new bone formation, bone volume, and mechanical properties. The CGP-HA and CGP-TCP scaffolds showed low biodegradability, whereas the CGP scaffolds were completely degraded. Osteoconductivity and osteoinductivity of the CGP and CGP-HA/TCP scaffolds were superior to the CGP-HA ones. The untreated and CGP-HA groups repaired mostly through fibrosis, while there were evidence of higher bone formation in the autograft, CGP and CGP-HA/TCP groups. In conclusion, addition of HA or ß-TCP alone into the CGP scaffolds impaired bone regeneration, while bone regeneration with the CGP and CGP-HA/TCP scaffolds was comparable with the autograft. Therefore, the CGP-HA/TCP scaffold can be a possible option to substitute the autologous bone grafting.

Investigations of silk fiber/calcium phosphate cement biocomposite for radial bone defect repair in rabbits.

BACKGROUND: This study aimed to investigate the effects of silk fiber (SF)/calcium phosphate cement (CPC) biocomposite on repairing radial bone defects in rabbits. METHODS: Four-month-old New Zealand rabbits were selected to create a bilateral radial bone defect model and divided into four groups according to implanted material: SF/CPC, SF/CPC/particulate bone (PB), PB, and control (C). The specimens were removed at four and eight postoperative weeks for general observation, X-ray examination, tissue slicing, scanning electron microscopy (SEM), and biomechanical testing. RESULTS: Postoperative X-ray showed no bone defect repair in group C and different degrees of bone defect repair in the other three groups. Imaging, histology, and SEM showed the following: group SF/CPC formed fine trabecular bone in week 4, while the maximum bending load in group SF/CPC in week 4 was significantly different from those in the other groups (P < 0.05). CONCLUSIONS: SF/CPC has good biocompatibility and bone-inducing ability, demonstrating its bone defect-repairing ability.

Comparison of high-resolution peripheral quantitative computerized tomography with dual-energy X-ray absorptiometry for measuring bone mineral density.

BACKGROUND/OBJECTIVES: The objective of this study was to compare the measurement of areal bone mineral density (aBMD) by dual-energy X-ray absorptiometry (DXA) with the measurement of volumetric bone mineral density (vBMD) by high-resolution peripheral computerized tomography (HR-pQCT) in subjects with a wide range of body mass indices (BMI). SUBJECTS/METHODS: We scanned the arms and legs of 49 premenopausal women, aged 21-45 years, with BMI from 18.5 to 46.5, by HR-pQCT and found that there was a nonsignificant change in vBMD associated with increased BMI, whereas aBMD (DXA) was associated with a positive significant increase. HR-pQCT scans a slice at the extremity of the tibia and radius, whereas DXA scans the entire leg and arm. RESULTS: The correlation coefficients (r) of BMD (DXA) of the legs with BMI were 0.552, P<0.001, with %fat it was 0.378, P<0.01 and with W it was 0.633, P<0.001. The r of BMD (DXA) of the arms with BMI was 0.804, P<0.001, with %fat it was 0.599, P<0.001 and with W it was 0.831, P<0.001, whereas the r of the average bone density (D100) of legs and arms measured by HR-pQCT with BMI, W and %fat were not significant. CONCLUSIONS: Although HR-pQCT and DXA scan different parts of the bone, the high r of BMD with BMI and low r of bone density measured by HR-pQCT with BMI suggest that BMD measured by DXA is artifactually increased in the presence of obesity.

Conventional, Bayesian, and Modified Prony's methods for characterizing fast and slow waves in equine cancellous bone.

Conventional, Bayesian, and the modified least-squares Prony's plus curve-fitting (MLSP + CF) methods were applied to data acquired using 1 MHz center frequency, broadband transducers on a single equine cancellous bone specimen that was systematically shortened from 11.8 mm down to 0.5 mm for a total of 24 sample thicknesses. Due to overlapping fast and slow waves, conventional analysis methods were restricted to data from sample thicknesses ranging from 11.8 mm to 6.0 mm. In contrast, Bayesian and MLSP + CF methods successfully separated fast and slow waves and provided reliable estimates of the ultrasonic properties of fast and slow waves for sample thicknesses ranging from 11.8 mm down to 3.5 mm. Comparisons of the three methods were carried out for phase velocity at the center frequency and the slope of the attenuation coefficient for the fast and slow waves. Good agreement among the three methods was also observed for average signal loss at the center frequency. The Bayesian and MLSP + CF approaches were able to separate the fast and slow waves and provide good estimates of the fast and slow wave properties even when the two wave modes overlapped in both time and frequency domains making conventional analysis methods unreliable.

The metaphyseal bone defect in distal radius fractures and its implication on trabecular remodeling-a histomorphometric study (case series).

BACKGROUND: The invention of the locking plate technology leads to alterations of treatment strategies at metaphyseal fracture sites with the concept of spontaneous remodeling of trabecular bone voids. Whereas trabecular regeneration has been proven in experimental animal studies, no histologic data exist on human fracture healing with special emphasis on bone voids. METHODS: In order to qualify the trabecular bone remodeling capacity in vivo, bone specimens from the metaphyseal bone void were analyzed 14 months after trauma using quantitative histomorphometry. Twenty-five patients with an unstable dorsally displaced distal radius fracture were fixed with a palmar locking plate without additional bone graft or substitute. At implant removal, specimens from the previous compression void were harvested with a trephine in a volar-dorsal direction. In 16 patients, histomorphometric analysis could be performed, comparing the dorsal trabecular network with the volar, non-compressed ultrastructure. RESULTS: Significant differences for bone volume/total volume (BV/TV), trabecular number (TbN) and trabecular separation (TbSp), but not for trabecular thickness (TbTh) and osteoid volume/total volume (OV/TV), were detected. Neither patient age, defect size nor gender had a significant influence on bone remodeling. CONCLUSIONS: The results of this study indicate that trabecular bone remodeling does not lead to pre-trauma bone quality in metaphyseal bone compression voids following reduction and application of a locking plate.

Trabecular and cortical microstructure and fragility of the distal radius in women.

Fragility fractures commonly involve metaphyses. The distal radius is assembled with a thin cortex formed by fusion (corticalization) of trabeculae arising from the periphery of the growth plate. Centrally positioned trabeculae reinforce the thin cortex and transfer loads from the joint to the proximal thicker cortical bone. We hypothesized that growth- and age-related deficits in trabecular bone disrupt this frugally assembled microarchitecture, producing bone fragility. The microarchitecture of the distal radius was measured using high-resolution peripheral quantitative computed tomography in 135 females with distal radial fractures, including 32 girls (aged 7 to 18 years), 35 premenopausal women (aged 18 to 44 years), and 68 postmenopausal women (aged 50 to 76 years). We also studied 240 fracture-free controls of comparable age and 47 healthy fracture-free premenopausal mother-daughter pairs (aged 30 to 55 and 7 to 20 years, respectively). In fracture-free girls and pre- and postmenopausal women, fewer or thinner trabeculae were associated with a smaller and more porous cortical area (r = 0.25 to 0.71 after age, height, and weight adjustment, all p < 0.05). Fewer and thinner trabeculae in daughters were associated with higher cortical porosity in their mothers (r = 0.30 to 0.47, all p < 0.05). Girls and premenopausal and postmenopausal women with forearm fractures had 0.3 to 0.7 standard deviations (SD) fewer or thinner trabeculae and higher cortical porosity than controls in one or more compartment; one SD trait difference conferred odds ratio (95% confidence interval) for fracture ranging from 1.56 (1.01-2.44) to 4.76 (2.86-7.69). Impaired trabecular corticalization during growth, and cortical and trabecular fragmentation during aging, may contribute to the fragility of the distal radius.

Compromised bone microarchitecture and estimated bone strength in young adults with cystic fibrosis.

CONTEXT: Young adults with cystic fibrosis (CF) are at risk for low bone density and fractures, but the underlying alterations in bone microarchitecture that may contribute to their increased fracture risk are currently unknown. OBJECTIVE: The main goal of this study was to use high-resolution peripheral quantitative computed tomography (HR-pQCT) to characterize the bone microarchitecture, volumetric bone mineral density (vBMD), and estimated strength of the radius and tibia in young adults with CF compared with healthy volunteers. DESIGN AND SETTING: This was a cross-sectional study at an outpatient clinical research center within a tertiary academic medical center. PARTICIPANTS: Thirty young adults with CF, 18 to 40 years of age, were evaluated and compared with 60 healthy volunteers matched by age (±2 years), gender, and race. MAIN OUTCOME MEASURES: The primary outcomes were HR-pQCT-derived cortical and trabecular vBMD, bone microarchitecture, and estimates of bone strength. RESULTS: At the radius and tibia, young adults with CF had smaller bone cross-sectional area and lower vBMD. Cortical and trabecular microarchitecture were compromised at both sites, most notably involving the trabecular bone of the tibia. These differences translated into lower estimated bone strength both at the radius and tibia. After accounting for body mass index differences, young adults with CF had lower bone area and estimated bone strength at the radius and had compromised trabecular microarchitecture and lower total and trabecular vBMD and estimated bone strength at the tibia. Alterations in trabecular bone density and microarchitecture and estimated strength measures of the tibia were also greater than expected based on dual-energy x-ray absorptiometry-derived areal BMD differences. CONCLUSIONS: Young adults with CF have compromised bone microarchitecture and lower estimated bone strength at both the radius and tibia, even after accounting for their smaller body size. These skeletal deficits likely explain the higher fracture risk observed in young adults with CF.

Microstructural parameters of bone evaluated using HR-pQCT correlate with the DXA-derived cortical index and the trabecular bone score in a cohort of randomly selected premenopausal women.

BACKGROUND: Areal bone mineral density is predictive for fracture risk. Microstructural bone parameters evaluated at the appendicular skeleton by high-resolution peripheral quantitative computed tomography (HR-pQCT) display differences between healthy patients and fracture patients. With the simple geometry of the cortex at the distal tibial diaphysis, a cortical index of the tibia combining material and mechanical properties correlated highly with bone strength ex vivo. The trabecular bone score derived from the scan of the lumbar spine by dual-energy X-ray absorptiometry (DXA) correlated ex vivo with the micro architectural parameters. It is unknown if these microstructural correlations could be made in healthy premenopausal women. METHODS: Randomly selected women between 20-40 years of age were examined by DXA and HR-pQCT at the standard regions of interest and at customized sub regions to focus on cortical and trabecular parameters of strength separately. For cortical strength, at the distal tibia the volumetric cortical index was calculated directly from HR-pQCT and the areal cortical index was derived from the DXA scan using a Canny threshold-based tool. For trabecular strength, the trabecular bone score was calculated based on the DXA scan of the lumbar spine and was compared with the corresponding parameters derived from the HR-pQCT measurements at radius and tibia. RESULTS: Seventy-two healthy women were included (average age 33.8 years, average BMI 23.2 kg/m(2)). The areal cortical index correlated highly with the volumetric cortical index at the distal tibia (R  =  0.798). The trabecular bone score correlated moderately with the microstructural parameters of the trabecular bone. CONCLUSION: This study in randomly selected premenopausal women demonstrated that microstructural parameters of the bone evaluated by HR-pQCT correlated with the DXA derived parameters of skeletal regions containing predominantly cortical or cancellous bone. Whether these indexes are suitable for better predictions of the fracture risk deserves further investigation.

Repair of bone defect by using vascular bundle implantation combined with Runx II gene-transfected adipose-derived stem cells and a biodegradable matrix.

A large hurdle in orthopedics today is the difficulty of dealing with the non-union of fractured bones. We therefore evaluated the effects of runt-related transcription factor II (Runx II), a factor used to create gene-modified tissue-engineered bone, combined with vascular bundle implantation for repairing segmental bone defects. Adenovirus Runx II gene (Ad-Runx II)-modified rabbit adipose-derived stem cells (ADSCs) were seeded onto polylactic acid/polycaprolacton (PLA/PCL) scaffolds to construct gene-modified tissue-engineered bone. The following four methods were used for repair in rabbit radial-defect (1.5 cm long) models: gene-modified tissue-engineered bone with vascular bundle (Group A), gene-modified tissue-engineered bone (Group B), non-gene-modified tissue-engineered bone with vascular bundle (Group C), and PLA/PCL scaffolds only (Group D). X-ray, histological examination, biomechanics analysis, and micro-angiography were conducted 4, 8, and 12 weeks later to determine angiogenesis and osteogenesis. The volume and speed of production of newly formed bones in Group A were significantly superior to those in other groups, and de-novo vascular network circulation from the vessel bundle through newly formed bone tissue was observed, with the defect being completely repaired. Group B showed a slightly better effect in terms of speed and quality of bone formation than Group C, whereas the bone defect in Group D was replaced by fibrous tissue. The maximal anti-bending strength in Group A was significantly higher than that in the other groups. Runx II gene therapy combined with vascular bundle implantation thus displays excellent abilities for osteoinduction and vascularization and is a promising method for the treatment of bone non-union and defect.

Mechanical competence of bone: a new parameter to grade trabecular bone fragility from tortuosity and elasticity.

With the elderly population increase, osteoporosis and its consequences have become not just a health issue but also a serious economic burden. The trabecular bone structure plays a very important role for the bone quality and mechanical competence of the scaffold. Currently, it is claimed that the trabecular microarchitecture understanding can improve the fracture risk prediction above 65%. Several parameters seem to be correlated providing structural details of the trabecular bone network. However, the tortuosity of the trabeculae has not yet been systematically taken into account and its contribution has not been fully investigated and understood. In this paper, we discuss the relationship between the trabecular tortuosity, connectivity, volume fraction, and elasticity, and provide a unified parameter to estimate the mechanical competence of the structure. It is shown that the trabecular network tortuosity presents high linear correlation with the other parameters and that the trabeculae tend to get aligned in the direction where the structure is mostly submitted to stress, corresponding to higher stiffness orientation. This new parameter will help to integrate the relevant information of bone microarchitecture quality and assess more directly the real trabecular fragility in osteoporotic patients.

A lower value for quantitative ultrasound at radius is an additional indicator of metabolic syndrome and cardiovascular disease risk.

BACKGROUND: The relationships between quantitative ultrasound (QUS) values, metabolic syndrome (MetS) and cardiovascular disease (CVD) risk are unclear. Objective The objective was to determine the relationships between QUS and MetS as well as CVD risk. DESIGN: This was a cross-sectional study conducted in Shanghai, China. PATIENTS: One-thousand four hundred and thirty-nine Chinese women and men with or without MetS were studied. MEASUREMENTS: Speed of sound (SOS) at radius, phalanx and tibia and their relationships with MetS and Framingham's 10-year cardiovascular disease risk scores were investigated. RESULTS: Premenopausal women with MetS had significant lower SOS at radius than those without MetS after adjusting for age, BMI and fat mass percentage (P = 0·02). The radius SOS was negatively associated with waist circumference (r = -0·109, P = 0·025), waist-to-hip ratio (r = -0·124, P = 0·01) and 2 h postprandial glucose level (r = -0·125, P = 0·012) in premenopausal women. Waist circumference, waist-to-hip ratio and 2 h postprandial glucose level increased with the decreasing tertiles of radius SOS after adjustment of age (P = 0·003, 0·002 and 0·008, respectively). The CVD risk increased with decreasing tertiles of radius SOS in postmenopausal women even after the adjustment of age, years since menopause, MetS components, smoking and alcohol habits (P < 0·001), but not in premenopausal women and men. CONCLUSIONS: Lower radius SOS is associated with greater risks of MetS and CVD in premenopausal and postmenopausal women, respectively. The QUS value derived from non-weight-bearing site, such as radius, may represent an additional indicator of MetS and CVD risk in women.

Detection of metal residues on bone using SEM-EDS--part II: Sharp force injury.

Scanning electron microscopy coupled with X-ray energy dispersive spectrometry (SEM-EDS) is extensively seen in the literature for the improvement of the macroscopic analysis of sharp lesions, but very few indications concerning its real potential in the forensic context, particularly in forensic anthropology, are at the moment available. This paper represents a pilot study for the analysis of the behaviour of metallic residues found on bone after sharp force injury. Fourteen lesions were made on human bone (radius), cleaned of all soft tissues, with seven different sharp tools (three metal instruments, three metal saws and a baked-clay knife). Tools and lesions underwent SEM-EDS. From 3 to 18 particles were detected on each lesion, whose diameter was included between 0.5 and 150 µm. In 58% of cases, particle composition was concordant with the instrument used. The results seem to suggest that sharp force injury frequently leaves relatively few residues on bone, particularly in the case of common types of metal. Saws showed slightly more contamination with other residues than knives, which may be explained by the capability of the saw's teeth to retain the residues of previously encountered material. In addition, metal residues related to the tool used to cut the bone were located on the edges/walls of lesions in the case of saw marks, whereas they were more frequently found on the kerf floor in the case of knives/scissors, with the exception of the baked clay knife which when it leaves residues at all, seemed to leave them equally divided between the floor, the edges and the surrounding bone.

Cortical consolidation of the radius and tibia in young men and women.

CONTEXT: Bone size, geometry, density, and microarchitecture are important determinants of bone strength. By understanding how these properties change during skeletal development, we can better understand bone fragility. OBJECTIVES: The aim of the study was to compare the geometry, microarchitecture, and strength of the radius and tibia in men and women at the end of adolescence and in young adulthood and to relate these properties to biochemical bone turnover markers and bone regulatory hormones. DESIGN: We conducted a cross-sectional study of 116 healthy men and women ages 16-18 (n = 56) and 30-32 (n = 60) yr. OUTCOME MEASURES: We used high-resolution peripheral quantitative computed tomography to measure bone size, geometry, and microarchitecture at the distal radius and tibia and micro-finite element modeling to estimate bone strength. We measured bone turnover markers (ß C-terminal telopeptide of type I collagen and amino-terminal propeptide of type I procollagen) and hormones known to affect bone metabolism (estradiol, testosterone, IGF-I, and PTH). RESULTS: Bone strength was greater in men than in women, and at the radius it was greater in men ages 30-32 yr than ages 16-18 yr. The gender difference was due to greater cortical perimeter, trabecular area, and trabecular density in men. The age difference was due to greater cortical thickness and cortical tissue mineral density and lower cortical porosity. IGF-I was related to two of these five key properties at the radius (cortical perimeter and cortical thickness). None of the hormones were predictors of density or structure at the tibia. CONCLUSIONS: Cortical modeling of long bones continues beyond the end of adolescence. IGF-I may be a determinant of this process at the radius.

Value of color Doppler ultrasonography and radiography for the assessment of the cancellous bone scaffold coated with nano-hydroxyapatite in repair of radial bone in rabbit.

PURPOSE: To evaluate the osteo-regenerative capacity of proprietary bone grafting material as a bone defect filler and osteogenetic stimulation to speed up bone healing too. METHODS: Eighteen adult male New Zealand white rabbits were anesthetized and a segmental full thickness bone defect of 10 mm in length was created in the middle of the right radial shaft in all rabbits. They were divided into two groups of 9 rabbits. Group I was considered as control and the fractured site was fixed using finger bone plate with 4 screws, whereas the cancellous bone scaffold coated with Nano-Hydroxyapatite was used to fill the gap after fracture fixation in Group II. Radiography, two dimensional and color Doppler ultrasonography were done before and after creating defects and on 0, 15, 30, 60 and 90 days to evaluate local reaction as far as new blood vessels network and callus formation are observed. RESULTS: On the radiographs during the whole process, bone repair in Group I was not as perfect as those in Group II samples and trace of internal callus filled the gap incompletely in 60 days in Group I, whereas in Group II internal callus almost was formed on 30 days and in addition intercortical callus was seen supporting to cover and filled the gap completely in this group in 60 day; Sonographic findings confirmed the protrusion of newly formed blood vascular network in 30 days in Group I and from 15 days in Group II and remarkably increased till end of observation period. CONCLUSIONS: The nano-hydroxyapatite with more features and shorter in time, made possible the reconstruction of bone tissue and alternative techniques as well as previous bone graft, also radiography and ultrasonography are reliable techniques to trace local reaction at proper time.

Value of color Doppler ultrasonography and radiography for the assessment of the cancellous bone scaffold coated with nano-hydroxyapatite in repair of radial bone in rabbit / Valor da ultrassonografia Doppler em cores e da radiografia na avaliação da capacidade osteo-regenerativa da nano-hidroxiapatita no reparo de osso radial em coelho

PURPOSE: To evaluate the osteo-regenerative capacity of proprietary bone grafting material as a bone defect filler and osteogenetic stimulation to speed up bone healing too. METHODS: Eighteen adult male New Zealand white rabbits were anesthetized and a segmental full thickness bone defect of 10 mm in length was created in the middle of the right radial shaft in all rabbits. They were divided into two groups of 9 rabbits. Group I was considered as control and the fractured site was fixed using finger bone plate with 4 screws, whereas the cancellous bone scaffold coated with Nano-Hydroxyapatite was used to fill the gap after fracture fixation in Group II. Radiography, two dimensional and color Doppler ultrasonography were done before and after creating defects and on 0, 15, 30, 60 and 90 days to evaluate local reaction as far as new blood vessels network and callus formation are observed. RESULTS: On the radiographs during the whole process, bone repair in Group I was not as perfect as those in Group II samples and trace of internal callus filled the gap incompletely in 60 days in Group I, whereas in Group II internal callus almost was formed on 30 days and in addition intercortical callus was seen supporting to cover and filled the gap completely in this group in 60 day; Sonographic findings confirmed the protrusion of newly formed blood vascular network in 30 days in Group I and from 15 days in Group II and remarkably increased till end of observation period. CONCLUSIONS: The nano-hydroxyapatite with more features and shorter in time, made possible the reconstruction of bone tissue and alternative techniques as well as previous bone graft, also radiography and ultrasonography are reliable techniques to trace local reaction at proper time.

OBJETIVO: Avaliar a capacidade osteo-regenerativa de biomaterial no preenchimento de defeito ósseo e como estímulo osteogênico para acelerar a cicatrização óssea. ÉTODOS: Dezoito coelhos brancos, Nova Zelandia, adultos, machos foram anestesiados e um defeito ósseo segmentar de toda a espessura e 10 mm de comprimento foi criado no meio do eixo do osso radial direito de todos os coelhos. Os animais foram distribuídos em dois grupos de nove: Grupo I foi considerado como controle e o local da fratura foi fixado usando placa de dedo de osso com quatro parafusos, enquanto o molde de osso esponjoso revestido com nano-hidroxiapatita foi usado para preencher o espaço após fixação da fratura no Grupo II. Radiografia, bidimensional e ultrassonografia Doppler colorida foi feita antes e após criar os defeitos e nos dias 0, 15, 30, 60 e 90 para avaliar a reação local tais como nova rede vascular e formação do calo ósseo. RESULTADOS: Nas radiografias durante todo o processo, o reparo ósseo no Grupo I não foi perfeito como no Grupo II; amostras e traços de calo ósseo preencheram o espaço de forma incompleta em 60 dias no Grupo I, enquanto no Grupo II o calo ósseo interno foi quase formado em 30 dias e, além disso, calo intercortical foi visto apoiar para revestir e preencher o espaço completamente em 60 dias; nos achados ultrassonográficos a protrusão da rede vascular neoformada em 30 dias no Grupo I e a partir de 15 dias no Grupo II e acentuado aumento até o fim do período de observação. CONCLUSÕES: A nano-hidroxiapatita, com mais propriedade e menor período de tempo, tornou possível a reconstrução de tecido ósseo e técnicas alternativas como o enxerto ósseo prévio, assim como a radiografia e a ultrassonografia são técnicas confiáveis para traçar a reação local em tempo adequado.

Visual grading of motion induced image degradation in high resolution peripheral computed tomography: impact of image quality on measures of bone density and micro-architecture.

Motion artifacts are a common finding during high-resolution peripheral quantitative computed tomography (HR-pQCT) image acquisitions. To date it is not clear (i) when to repeat an acquisition, (ii) when to exclude a motion-degraded dataset post hoc, and (iii) how motion induced artifacts impact measures of trabecular and cortical parameters. In this study we present inter- and intra-observer reproducibility of a qualitative image quality grading score and report the prevalence of repeat acquisitions in our population. Finally the errors in bone density and micro-architectural parameters estimated from repeat acquisitions with and without motion degradation are presented. The relationship between these errors and the image quality grade is evaluated for each parameter. Repeat acquisitions performed due to operator-observed motion in the reconstructed image occurred for 22.7% of the exams (29.7% radius, 15.7% tibia). Of this subset, 88 exams with repeat acquisitions had at least one acquisition graded 1 (best quality). In this subset, the percent differences in bone density and micro-architecture measures tended to increase as the relative image quality decreased. Micro-architectural parameters were more sensitive to motion compared to geometric and densitometric parameters. These results provide estimates of the error in bone quality measures due to motion artifacts and provide an initial framework for developing standardized quality control criteria for cross-sectional and longitudinal HR-pQCT studies.

Poor trabecular microarchitecture in male current smokers: the cross-sectional STRAMBO study.

Current smoking (but not past smoking) is associated with higher risk of fracture independent of areal bone mineral density (aBMD); however, the pathophysiologic mechanism underlying this association is not clear. In 810 men aged 60-87, aBMD was measured by dual-energy X-ray absorptiometry. Bone microarchitecture at the distal radius and distal tibia was assessed by high-resolution peripheral quantitative computed tomography using the Xtreme CT Scanco device. Current smokers (n = 47) had lower trabecular volumetric density (Dtrab), lower trabecular number (TbN), more heterogenous trabecular network (higher trabecular spacing standard deviation [TbSpSD]), as well as higher urinary deoxypyridinoline and higher C-reactive protein levels in comparison with 261 men who never smoked (adjusted for age, weight, height, time spent outdoors, physical activity, and intake of alcohol, caffeine, and calcium). Abnormal values (lower Dtrab and TbN, higher TbSpSD, deoxypyridinoline, and C-reactive protein) were found mainly in 21 current smokers who smoked eight or more cigarettes per day. Cortical parameters and aBMD did not differ from the never-smokers. In 502 former smokers, aBMD and all bone microarchitectural parameters did not differ from the never-smokers. At the tibia (not radius), Dtrab decreased, whereas TbSpSD slightly increased across quartiles of smoking intensity (number of pack-years). In conclusion, older men who are moderate current smokers have poor trabecular (but not cortical) microarchitecture, which is not reflected by a decrease in aBMD.