Bone Quality Parameters Research Articles

The association between plasma homocysteine levels and bone quality and bone mineral density parameters in older persons

IntroductionHigh plasma homocysteine levels have been associated with incident osteoporotic fractures, but the mechanisms underlying this association are still unknown. It has been hypothesized that homocysteine might interfere with collagen cross-linking in bone, thereby weakening bone structure. Therefore, we wanted to investigate whether plasma homocysteine levels are associated with bone quality parameters, rather than with bone mineral density. MethodsCross-sectional data of the B-PROOF study (n=1227) and of two cohorts of the Rotterdam Study (RS-I (n=2850) and RS-II (n=2023)) were used. Data on bone mineral density of the femoral neck and lumbar spine were obtained in these participants using dual-energy X-ray assessment (DXA). In addition, participants of B-PROOF and RS-I underwent quantitative ultrasound measurement of the calcaneus, as a marker for bone quality. Multiple linear regression analysis was used to investigate the associations between natural-log transformed plasma levels of homocysteine and bone mineral density or ultrasound parameters. ResultsNatural-log transformed homocysteine levels were inversely associated with femoral neck bone mineral density in the two cohorts of the Rotterdam Study (B=−0.025, p=0.004 and B=−0.024, p=0.024). In B-PROOF, no association was found. Pooled data analysis showed significant associations between homocysteine and bone mineral density at both femoral neck (B=−0.032, p=0.010) and lumbar spine (B=−0.098, p=0.021). Higher natural-log transformed homocysteine levels associated significantly with lower bone ultrasound attenuation in B-PROOF (B=−3.7, p=0.009) and speed of sound in both B-PROOF (B=−8.9, p=0.001) and RS-I (B=−14.5, p=0.003), indicating lower bone quality. Pooled analysis confirmed the association between homocysteine and SOS (B=−13.1, p=0.016). Results from ANCOVA-analysis indicate that differences in SOS and BUA between participants having a plasma homocysteine level above or below median correspond to 0.14 and 0.09 SD, respectively. DiscussionIn this study, plasma levels of homocysteine were significantly inversely associated with both bone ultrasound parameters and with bone mineral density. However, the size of the associations seems to be of limited clinical relevance and may therefore not explain the previously observed association between plasma homocysteine and osteoporotic fracture incidence.

The bone regenerative effects of fucosterol in in vitro and in vivo models of postmenopausal osteoporosis

The aim of this study was to investigate the bone regenerative effects of fucosterol in estrogen-deficient ovariectomized (OVX) rats. Bone regeneration was assessed in fucosterol-treated MG63 cells in vitro via assays for osteoblast proliferation, alkaline phosphatase, and osteoclast differentiation. Osteoblast proliferation rates, alkaline phosphatase activity, and mineralization were increased in the fucosterol-treated group. Moreover, differentiation of osteoclasts was decreased in the fucosterol-treated group. In the in vivo assay, female rats were OVX. Twelve weeks after ovariectomy, rats were divided into seven groups, each oral administrate everyday for 7 weeks. The bone mineral density of femoral bones was higher in fucosterol groups than in OVX control, and body weight was lower in fucosterol groups. Among bone-quality parameters, bone volume/total volume increased and trabecular separation decreased in fucosterol groups relative to the OVX control. Bone formation and resorption were evaluated using the serum biomarkers osteocalcin and CTx. Fucosterol tripled the level of serum osteocalcin relative to the OVX group and reduced the serum level of CTx. These results suggest that fucosterol has the dual potentials to activate osteoblasts to stimulate bone formation and suppress differentiation of osteoclasts so as to reduce bone resorption.

Lean mass as a predictor of bone density and microarchitecture in adult obese individuals with metabolic syndrome

The effects of obesity and metabolic syndrome (MS) on bone health are controversial. Furthermore, the relationship between body composition and bone quality has not yet been determined in this context. The aim of this study was to investigate the correlations between body composition and bone mineral density (BMD) and bone microstructure in obese individuals with MS. This cross-sectional study assessed 50 obese individuals with MS with respect to their body composition and BMD, both assessed using dual X-ray absorptiometry, and bone microarchitecture, assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT) of the distal tibia and radius. Several HR-pQCT measurements exhibited statistically significant correlations with lean mass. Lean mass was positively correlated with parameters of better bone quality (r: 0.316–0.470) and negatively correlated with parameters of greater bone fragility (r: −0.460 to −0.310). Positive correlations were also observed between lean mass and BMD of the total femur and radius 33%. Fat mass was not significantly correlated with BMD or any HR-pQCT measurements. Our data suggest that lean mass might be a predictor of bone health in obese individuals with MS.

Low-Energy Fractures without Low T-Scores Characteristic of Osteoporosis

Osteoporotic fractures commonly occur after low-energy trauma in postmenopausal women with reduced bone quantity documented by low bone mineral density (BMD). Low-energy fractures, however, have also been reported to occur in premenopausal women with normal or near-normal BMD, suggesting the existence of a bone quality abnormality. Bone quality and quantity were evaluated in a cross-sectional study of three groups of premenopausal white females: (1) twenty-five subjects with low-energy fracture(s) and BMD in the normal range (t-scores > -2.0), (2) eighteen subjects with low-energy fracture(s) and BMD in the osteoporotic range (t-scores ≤ -2.5), and (3) fourteen healthy volunteers (controls). Bone quality was assessed with use of Fourier transform infrared spectroscopy and histomorphometry in iliac crest bone samples obtained from all subjects; bone quantity was assessed by dual x-ray absorptiometry and histomorphometry. The collagen crosslinking ratio in the non-low-BMD subjects with fractures was 13% greater than the ratio in the low-BMD subjects with fractures and 14% greater than the ratio in the controls (p < 0.001 for both). Cancellous bone volume was 29% greater (p < 0.01) and trabecular separation was 31% less (p < 0.01) in the non-low-BMD subjects with fractures than in the low-BMD subjects with fractures; the values in the non-low-BMD subjects did not differ from those in the controls. Bone turnover did not differ among the groups, and osteomalacia was not present in any subject. Thus, the non-low-BMD subjects with fractures maintained bone quantity, but the collagen crosslinking ratio, a parameter of bone quality, was abnormal. In contrast, the low-BMD subjects with fractures did not have this collagen crosslinking abnormality but did have abnormal bone quantity. This study highlights a collagen crosslinking abnormality in patients with low-energy fractures and nonosteoporotic t-scores. Reports have indicated that altered collagen crosslinking is associated with subnormal fracture resistance. A finding of nonosteoporotic bone mass in a patient with low-energy fractures would justify assessment of bone material quality, which currently requires a bone biopsy. Further studies are needed to search for possible noninvasive tests to diagnose abnormal crosslinking. Since no specific therapies for abnormal collagen crosslinking are currently available, studies are also needed to explore novel therapeutic modalities to reverse the underlying collagen crosslinking abnormality. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Which factors prognosticate rotational instability following lumbar laminectomy?

Reduced strength and stiffness of lumbar spinal motion segments following laminectomy may lead to instability. Factors that predict shear biomechanical properties of the lumbar spine were previously published. The purpose of the present study was to predict spinal torsion biomechanical properties with and without laminectomy from a total of 21 imaging parameters. Radiographs and MRI of ten human cadaveric lumbar spines (mean age 75.5, range 59-88 years) were obtained to quantify geometry and degeneration of the motion segments. Additionally, dual X-ray absorptiometry (DXA) scans were performed to measure bone mineral content and density. Facet-sparing lumbar laminectomy was performed either on L2 or L4. Spinal motion segments were dissected (L2-L3 and L4-L5) and tested in torsion, under 1,600 N axial compression. Torsion moment to failure (TMF), early torsion stiffness (ETS, at 20-40 % TMF) and late torsion stiffness (LTS, at 60-80 % TMF) were determined and bivariate correlations with all parameters were established. For dichotomized parameters, independent-sample t tests were used. Univariate analyses showed that a range of geometric characteristics and disc and bone quality parameters were associated with torsion biomechanical properties of lumbar segments. Multivariate models showed that ETS, LTS and TMF could be predicted for segments without laminectomy (r (2) values 0.693, 0.610 and 0.452, respectively) and with laminectomy (r (2) values 0.952, 0.871 and 0.932, respectively), with DXA-derived measures of bone quality and quantity as the main predictors. Vertebral bone content and geometry, i.e. intervertebral disc width, frontal area and facet joint tropism, were found to be strong predictors of ETS, LTS and TMF following laminectomy, suggesting that these variables could predict the possible development of post-operative rotational instability following lumbar laminectomy. Proposed diagnostic parameters might aid surgical decision-making when deciding upon the use of instrumentation techniques.

Dioxin-like compounds and bone quality in Cree women of Eastern James Bay (Canada): a cross-sectional study

BackgroundAboriginal populations living in Canada’s northern regions are exposed to a number of persistent organic pollutants through their traditional diet which includes substantial amounts of predator fish species. Exposure to dioxin-like compounds (DLCs) can cause a variety of toxic effects including adverse effects on bone tissue. This descriptive cross-sectional study was conducted to investigate the relationship between plasma concentrations of DLCs and bone quality parameters in Cree women of Eastern James Bay (Canada).MethodsTwo hundred and forty-nine Cree women from seven communities in Eastern James Bay (Canada), aged 35 to 74 years old, participated in the study. In order to determine the total DLC concentration in plasma samples of participants, we measured the aryl hydrocarbon receptor-mediated transcriptional activity elicited by plasma sample extracts using a luciferase reporter gene assay. Plasma concentrations of mono-ortho-substituted dioxin-like polychlorinated biphenyls (DL-PCBs) 105, 118 and 156 were measured by gas chromatography–mass spectrometry. Bone quality parameters (speed of sound, m/s; broadband ultrasound attenuation, dB/MHz; stiffness index, %) were assessed by quantitative ultrasound at the right calcaneus with the Achilles InSight system. Several factors known to be associated with osteoporosis were documented by questionnaire. Multiple linear regression models were constructed for the three ultrasound parameters.ResultsDL-PCBs 105 and 118 concentrations, but not the global DLC concentration, were inversely associated with the stiffness index, even after adjusting for several confounding factors. The stiffness index (log) decreased by −0.22% (p=0.0414) and −0.04% (p=0.0483) with an increase of one μg/L in plasma concentrations of DL-PCB 105 and DL-PCB 118, respectively. Other factors, including age, height, smoking status, menopausal status and the percentage of omega-6 polyunsaturated fatty acids (PUFAs) in erythrocyte membranes were negatively associated with one of the ultrasound parameters, while the percentage of omega-3 PUFAs in these membranes and levels of physical activity and education were positively associated with them.ConclusionsOur results show that an increase in plasma concentrations of DL-PCBs 105 and 118 was negatively associated with stiffness index, a measure of bone quality/strength, in women of this population. In addition to environmental contaminants, future studies should also consider PUFA intake as a factor influencing bone quality.

Abnormal bone quality versus low bone mineral density in adolescent idiopathic scoliosis: a case-control study with in vivo high-resolution peripheral quantitative computed tomography

Background contextAdolescent idiopathic scoliosis (AIS) is associated with low bone mass that could persist into early adulthood and is an important prognostic factor for curve progression. Previous studies were confined to areal bone mineral density measurement that was a two-dimensional investigation for a three-dimensional structure. Evaluation of volumetric BMD (vBMD) and other bone quality parameters are important for gaining in-depth understanding of the etiopathogenesis of AIS. PurposeThe objective of this study was to carry out direct in vivo measurement of bone quality in AIS using high-resolution peripheral quantitative computed tomography (HR-pQCT) and compare the correlation of bone quality with osteopenia between AIS and control subjects. Study design/settingA case-control study. Patient sampleNewly diagnosed AIS girls (n=112) and non-AIS girls (n=115) between 11 and 13 years. Outcome measuresAreal bone mineral density of bilateral femoral necks and HR-pQCT of the nondominant distal radius were performed. MethodsAreal bone mineral density of femoral necks was measured by dual-energy X-ray absorptiometry. Subjects were classified into the osteopenic (Z score less than or equal to −1) and nonosteopenic (Z score more than −1) groups. Bone quality parameters, including bone morphometry, trabecular bone microarchitecture, and vBMD, were measured by HR-pQCT (XtremeCT; Scanco Medical, Zurich, Switzerland). ResultsIn AIS, the osteopenic group had lower measurements in cortical area, cortical thickness, average vBMD, compact bone vBMD, trabecular vBMD, trabecular bone volume to tissue volume ratio, and trabecular thickness compared with nonosteopenic AIS subjects. In contrast, among the non-AIS controls, the osteopenic group had lower measurements only in bone morphometry, average vBMD, and compact bone vBMD but not in trabecular vBMD and all other trabecular bone microarchitecture parameters. ConclusionsThis is the first study using HR-pQCT to compare the correlation of bone quality with osteopenia in AIS and non-AIS subjects. It provides new insights and highlights the unique bone quality profile with predominant changes in the trabecular compartment in association with osteopenia being notably only detected in the AIS subjects. Further studies in this area are warranted for defining the metabolic nature and biomechanical sequelae of derangement in bone mass and bone quality and their roles in the etiopathogenesis of AIS.

Differences in microarchitecture parameters of bone quality in low and high turnover renal osteodystrophy assessed by HR-pQCT

Differences in microarchitecture parameters of bone quality in low and high turnover renal osteodystrophy assessed by HR-pQCT

BMD, Micro-Architecture Estimation (TBS) and Vertebral Fracture Assessment (VFA) Extracted From a Single DXA Device in Combination With Clinical Risk Factors Improve Significantly the Identification of Women at High Risk of Fracture

BMD, Micro-Architecture Estimation (TBS) and Vertebral Fracture Assessment (VFA) Extracted From a Single DXA Device in Combination With Clinical Risk Factors Improve Significantly the Identification of Women at High Risk of Fracture

Effect of whole body vibration (WBV) therapy on bone density and bone quality in osteopenic girls with adolescent idiopathic scoliosis: a randomized, controlled trial

The aim of this randomized controlled trial was to determine whether whole body vibration (WBV) therapy was effective for treating osteopenia in adolescent idiopathic scoliosis (AIS) patients. Results showed that WBV was effective for improving areal bone mineral density (aBMD) at the femoral neck of the dominant side and lumbar spine BMC in AIS subjects. AIS is associated with osteopenia. Although WBV was shown to have skeletal anabolic effects in animal studies, its effect on AIS subjects remained unknown. The objective of this study was to determine whether WBV could improve bone mineral density (BMD) and bone quality for osteopenia in AIS subjects. This was a randomized, controlled trial recruiting 149 AIS girls between 15 and 25 years old and with bone mineral density (BMD) Z-scores <-1. They were randomly assigned to the Treatment or Control groups. The Treatment group (n = 61) stood on a low-magnitude high-frequency WBV platform 20 min/day, 5 days/week for 12 months. The Control group (n = 63) received observation alone. Bone measurement was done at baseline and at 12 months: (1) aBMD and BMC at femoral necks and lumbar spine using dual-energy X-ray absorptiometry (DXA) and (2) bone quality including bone morphometry, volumetric BMD (vBMD), and trabecular bone microarchitecture using high-resolution peripheral quantitative computed tomography (HR-pQCT) for nondominant distal radius and bilateral distal tibiae. The Treatment group had numerically greater increases in all DXA parameters with a statistically significant difference being detected for the absolute and percentage increases in femoral neck aBMD at the dominant leg (0.015 (SD = 0.031)g/cm(2), 2.15 (SD = 4.32)%) and the absolute increase in lumbar spine BMC (1.17 (SD = 2.05)g) in the Treatment group as compared with the Control group (0.00084 (SD = 0.026)g/cm(2), 0.13 (SD = 3.62)% and 0.47 (SD = 1.88)g, respectively). WBV had no significant effect for other bone quality parameters. WBV was effective for improving aBMD at the femoral neck of the dominant side and lumbar spine BMC in AIS subjects.

Assessment of potential orthodontic mini-implant insertion sites based on anatomical hard tissue parameters: a systematic review.

To estimate the applicability of potential sites for insertion of orthodontic mini-implants (OMIs) by a systematic review of studies that used computed tomography (CT) or cone beam CT to evaluate anatomical bone quality and quantity parameters, such as bone thickness, available space, and bone density. Medline and the Cochrane Database of Systematic Reviews were searched to identify all relevant papers. Several key words were used, such as computerized/computed tomography, mini-implants, and OMIs. The anatomical variables that were assigned in each article to a specific site suggesting it as the ideal or best alternative were assessed separately and evaluated with a scoring system. Twenty-two articles were included in the study. The most favorable areas for OMI insertion in the maxilla are proposed between the first and second molars buccally and palatally. The best area in the mandible is also between the first and second molars, both buccally and lingually. In the palate, the paramedian area 3 to 6 mm posterior to and 2 to 9 mm lateral to the incisive foramen was identified as the best site for OMI placement. Despite the heterogeneity of the studies, there was considerable agreement regarding the optimal site for OMI insertion among most studies that investigated anatomical hard tissue parameters based on CT or CBCT data. In this respect, the posterior area from the second premolar to the second molar is the best option for OMI placement in alveolar bone.

Association between plasma homocysteine and bone density and quality parameters in the elderly

Association between plasma homocysteine and bone density and quality parameters in the elderly

Which factors prognosticate spinal instability following lumbar laminectomy?

PurposeReduced strength and shear stiffness (SS) of lumbar motion segments following laminectomy may lead to instability. The purpose of the present study was to assess a broad range of parameters as potential predictors of shear biomechanical properties of the lumbar spine.MethodsRadiographs and MRI of all lumbar spines were obtained to classify geometry and degeneration of the motion segments. Additionally, dual X-ray absorptiometry (DXA) scans were performed to measure bone mineral content and density (BMC and BMD). Facet sparing lumbar laminectomy was performed either on L2 or L4, in 10 human cadaveric lumbar spines (mean age 72.1 years, range 53–89 years). Spinal motion segments were dissected (L2–L3 and L4–L5) and tested in shear, under simultaneously loading with 1600 N axial compression. Shear stiffness, shear yield force (SYF) and shear force to failure (SFF) were determined and statistical correlations with all parameters were established.ResultsFollowing laminectomy, SS, SYF, and SFF declined (by respectively 24, 41, and 44%). For segments with laminectomy, SS was significantly correlated with intervertebral disc degeneration and facet joint degeneration (Pfirrmann: r = 0.64; Griffith: r = 0.70; Lane: r = 0.73 and Pathria: r = 0.64), SYF was correlated with intervertebral disc geometry (r = 0.66 for length; r = 0.66 for surface and r = 0.68 for volume), BMC (r = 0.65) and frontal area (r = 0.75), and SFF was correlated with disc length (r = 0.73) and BMC (r = 0.81). For untreated segments, SS was significantly correlated with facet joint tropism (r = 0.71), SYF was correlated with pedicle geometry (r = 0.83), and SFF was correlated with BMC (r = 0.85), BMD (r = 0.75) and frontal area (r = 0.75). SS, SYF and SFF could be predicted for segments with laminectomy (r 2 values respectively: 0.53, 0.81 and 0.77) and without laminectomy (r 2 value respectively: 0.50, 0.83 and 0.83).ConclusionsSignificant loss of strength and SS are predicted by BMC, BMD, intervertebral disc geometry and degenerative parameters, suggesting that low BMC or BMD, small intervertebral discs and absence of osteophytes could predict the possible development of post-operative instability following lumbar laminectomy.

Quality control for bone quality parameters affected by subject motion in high-resolution peripheral quantitative computed tomography

Subject motion during high-resolution peripheral quantitative computed tomography (HR-pQCT) causes image artifacts that affect morphological analysis of bone quality. The aim of our study was to determine effectiveness of techniques for quality control in the presence of motion in vivo including automated and manual approaches. First, repeatability of manual grading was determined within and between laboratories. Given proper training using a standardized scale and training images (provided by the manufacturer), we found that manual grading is suitable for repeatable image quality grading within and across sites (ICC>0.7). Both a new automated technique providing motion measures based on projection moments, and traditional manual grading (1=best, 5=worst) were subsequently used to assess subject data for motion in N=137 image pairs (scan/re-scan) from the Canadian Multicentre Osteoporosis Study (CaMos) Calgary cohort. High quality image pairs were selected and measurement precision was estimated by calculating the coefficient of variation (CV). Consistent with previous data, density parameters (e.g. total bone mineral density) are more robust than structural (e.g. trabecular number) or finite element parameters (e.g. failure load). To obtain acceptable measurement precision, images should not exceed a manual grading of 3 (on a scale from 1 to 5) or an automatic (εT) grading of 1.2. Automatic and manual grading provide comparable quality control, but the advantage of the automated technique is its ability to provide a motion value at scan time (providing a basis for real time decision regarding re-scan requirements), and the assessment is objective. Notably, automatic motion measurement can be performed retrospectively based on original scan data, and is therefore well suited for multi-center studies as well as any research where objective quality control is paramount.

Chemical and Biological Characteristics of Different Hydrated Monocalcium Phosphates for Broiler Chickens

Chemical and Biological Characteristics of Different Hydrated Monocalcium Phosphates for Broiler ChickensThree hydrated monocalcium phosphates differing in purity (with or without monetite, or monetite and calcite) and in crystalline structure were used in broiler chickens diets. The performance indices, concentration of Ca, P and Mg and activity of alkaline phosphatase in blood plasma, the content of these mineral elements in bones, and physico-mechanical parameters of femur and tibia bones were recorded. Body weight on 35th day of life, feed intake and mechanical parameters of bone quality were slightly affected by the type of phosphates used. Higher Ca and P concentration in blood was stated in chickens fed diets with greater purity of phosphates, but activity of alkaline phosphatase has increased with the admixture of monetite or calcite used in phosphates. The best parameters of bone quality were found in the treatment in which hydrated monocalcium phosphate (MCP) with admixture of monetite and calcite was applied. Higher concentration of both Ca and Mg in bone was determined in chickens fed diets with pure phosphates.

Regeneration of Bone Mass and Bone Quality around Implant with Grooves for Aligning Bone Cells in Rabbit Hindlimb Bones

It was reported that one-dimensionally elongated pores in implants promote the production of new bone tissue possessing both high bone density and the preferential alignment of biological apatite (BAp) c-axis/collagen as a bone quality parameter. This finding indicates that the anisotropic orientation and/or migration of osteoblasts guided by the grooved-pore surface affected the establishment of the anisotropic microstructure of bone tissue. In this study, a grooved polytetrafluoroethylene (Teflon) implant, which may have a role in regulating osteoblast arrangement, was prepared to investigate the relationship between cell behavior and bone microstructure. A cylindrical Teflon implant with 8 grooves on its side was prepared. The width and depth of the groove cross-section were 0.5 and 0.75 mm, respectively. Each implant was inserted in a drill-hole defect created on a rabbit femur such that the groove direction was parallel or perpendicular to the long bone axis in which the BAp c-axis aligns one-dimensionally. The Young’s modulus of Teflon is approximately 0.5 GPa, much lower than that of bone; therefore, the effects of applied stress can be eliminated in this model. The oriented new bone was preferentially produced along the grooved surface. The alignment direction of the BAp c-axis was almost parallel to the grooved surface even near the surface vertically aligned to the long bone axis. The geometry of the implant surface can control the organization of BAp alignment through the arrangement of osteoblasts to orient and subsequently to migrate along the surface direction; hence, implant geometry, particularly the groove, is considered an important factor controlling the BAp orientation of regenerated bone tissues.

7B34 骨アパタイト配向性に基づく再生・疾患骨の骨質評価と力学特性への影響(OS08 骨質から視る骨のバイオメカニクス)

7B34 骨アパタイト配向性に基づく再生・疾患骨の骨質評価と力学特性への影響(OS08 骨質から視る骨のバイオメカニクス)

Recomendaciones sobre ranelato de estroncio en el tratamiento de la osteoporosis

At present, several interventions are available to reduce the incidence of osteoporotic fractures, such as lifestyle modifications, reducing the risk of falls and specific pharmacological treatments.Strontium ranelate is the only anti-osteoporotic drug with a dual mechanism of action, since it inhibits bone resorption while stimulating bone formation.The studies performed to date have shown the ability of this drug to improve bone quality parameters (microarchitecture), increase bone mineral density and reduce the risk of vertebral and nonvertebral fractures. Strontium ranelate has demonstrated efficacy in osteopenic and osteoporotic women, with or without fractures, in the first few years after menopause and in older women.Safety data are available for 10 years and under real conditions of administration, and demonstrate an adequate safety profile and tolerance.Due to its efficacy, safety and years of use, strontium ranelate is a first choice treatment for women with postmenopausal osteoporosis and fracture risk.

Boys with haemophilia have low trabecular bone mineral density and sarcopenia, but normal bone strength at the radius

Although a decreased areal bone mineral density (BMD) has been reported in patients with haemophilia, data are lacking that would reflect the three-dimensional structure of the bone and the muscle-bone relationship. We aimed to assess volumetric BMD, bone geometry and muscle-bone phenotype in boys with haemophilia, and to describe the association between clinical characteristics of haemophilia and bone quality and structure. A cross-sectional study was conducted in 41 boys with haemophilia (mean age 12.4, range 6.6-19.8 years) using peripheral quantitative CT (pQCT) at the nondominant forearm. Results were transformed into Z-scores using previously published reference data. Significant differences were tested by one-sample t-test or sign test. Two-sample t-test and anova were used to compare results between subgroups of patients divided according to the severity of the disease, the fracture history and the number of joint and muscle bleedings. Boys with haemophilia had a decreased trabecular volumetric BMD (mean Z-score -0.5, P < 0.01), while their cortical volumetric BMD was increased (mean Z-score 0.4, P < 0.05). The volumetric bone mineral content and the bone geometry at the radial diaphysis were normal when adjusted for patients' shorter body height. Muscle area was decreased (mean Z-score -1.0, P < 0.001), irrespective of age. No association was observed of bone quality parameters and bone geometry with the disease severity, fracture history or number of bleedings. Bone strength measured at the diaphysis of the radius is not impaired in boys with haemophilia. The finding of the decreased trabecular bone density can be most likely attributed to their sarcopenia.

Mild chronic whole body vibration does not affect bone mineral mass or density in young females

Whole body vibration (WBV) is increasingly being used in several physical therapy settings. In order to evaluate the ability of WBV to affect bone mineral component, thirty-six young (mean age 25.3 ± 5.26 yrs) healthy females underwent eight weeks of WBV exercise (nineteen minutes per session, two session a week; vibration amplitude 2.0-5.0 mm, vibration frequency 40-60 Hz). Bone mineral content (BMC) and density (BMD) were evaluated before and after the WBV trial using dual-energy X-ray absorptiometry in the whole body mode. Data were analyzed with repeated measures analysis of variance. Results show that neither BMC nor BMD were significantly affected by the WBV trial at the total body or regional skeletal level. It is concluded that, under the current experimental conditions, WBV exercise is not able to improve bone mineral parameters in young healthy females before the peak bone mass. Further investigation is required to recommend WBV for increasing bone quality parameters in premenopausal women.