Can the WHO definition of osteoporosis be applied to multi-site axial transmission quantitative ultrasound?

Unsupervised Learning-Based Measurement of Ultrasonic Axial Transmission Velocity in Neonatal Bone

OBJECTIVES

To develop a robust algorithm for estimating ultrasonic axial transmission velocity from neonatal tibial bone, and to investigate the relationships between ultrasound velocity and neonatal anthropometric measurements as well as clinical biochemical markers of skeletal health.

METHODS

This study presents an unsupervised learning approach for the automatic detection of first arrival time and estimation of ultrasonic velocity from axial transmission waveforms, which potentially indicates bone quality. The proposed method combines the ReliefF algorithm and fuzzy C-means clustering. It was first validated using an in vitro dataset measured from a Sawbones phantom. It was subsequently applied on in vivo signals collected from 40 infants, comprising 21 males and 19 females. The extracted neonatal ultrasonic velocity was subjected to statistical analysis to explore correlations with the infants' anthropometric features and biochemical indicators.

RESULTS

The results of in vivo data analysis revealed significant correlations between the extracted ultrasonic velocity and the neonatal anthropometric measurements and biochemical markers. The velocity of first arrival signals showed good associations with body weight (ρ = 0.583, P value <.001), body length (ρ = 0.583, P value <.001), and gestational age (ρ = 0.557, P value <.001).

CONCLUSION

These findings suggest that fuzzy C-means clustering is highly effective in extracting ultrasonic propagating velocity in bone and reliably applicable in in vivo measurement. This work is a preliminary study that holds promise in advancing the development of a standardized ultrasonic tool for assessing neonatal bone health. Such advancements are crucial in the accurate diagnosis of bone growth disorders.

UBAP2 plays a role in bone homeostasis through the regulation of osteoblastogenesis and osteoclastogenesis

Osteoporosis is a condition characterized by decreased bone mineral density (BMD) and reduced bone strength, leading to an increased risk of fractures. Here, to identify novel risk variants for susceptibility to osteoporosis-related traits, an exome-wide association study is performed with 6,485 exonic single nucleotide polymorphisms (SNPs) in 2,666 women of two Korean study cohorts. The rs2781 SNP in UBAP2 gene is suggestively associated with osteoporosis and BMD with p-values of 6.1 × 10-7 (odds ratio = 1.72) and 1.1 × 10-7 in the case-control and quantitative analyzes, respectively. Knockdown of Ubap2 in mouse cells decreases osteoblastogenesis and increases osteoclastogenesis, and knockdown of ubap2 in zebrafish reveals abnormal bone formation. Ubap2 expression is associated with E-cadherin (Cdh1) and Fra1 (Fosl1) expression in the osteclastogenesis-induced monocytes. UBAP2 mRNA levels are significantly reduced in bone marrow, but increased in peripheral blood, from women with osteoporosis compared to controls. UBAP2 protein level is correlated with the blood plasma level of the representative osteoporosis biomarker osteocalcin. These results suggest that UBAP2 has a critical role in bone homeostasis through the regulation of bone remodeling.

Hormonal contraceptive use, bone density and biochemical markers of bone metabolism in British Army recruits

INTRODUCTION

Hormonal contraceptive use might impair bone health and increase the risk of stress fracture by decreasing endogenous oestrogen production, a central regulator of bone metabolism. This cross-sectional study investigated bone density and biochemical markers of bone metabolism in women taking hormonal contraceptives on entry to basic military training.

METHODS

Forty-five female British Army recruits had biochemical markers of bone metabolism, areal bone mineral density (aBMD) and tibial speed of sound (tSOS) measured at the start of basic military training. Participants were compared by their method of hormonal contraception: no hormonal contraception (NONE), combined contraceptive pill (CP) or depot-medroxyprogesterone acetate (DMPA) (20±2.8 years, 1.64±0.63 m, 61.7±6.2 kg).

RESULTS

aBMD was not different between groups (p≥0.204), but tSOS was higher in NONE (3%, p=0.014) when compared with DMPA users. Beta C-terminal telopeptide was higher in NONE (45%, p=0.037) and DMPA users (90%, p=0.003) compared with CP users. Procollagen type 1 N-terminal propeptide was higher in DMPA users compared with NONE (43%, p=0.045) and CP users (127%, p=0.001), and higher in NONE compared with CP users (59%, p=0.014). Bone alkaline phosphatase was higher in DMPA users compared with CP users (56%, p=0.044).

CONCLUSIONS

DMPA use was associated with increased bone turnover and decreased cortical bone integrity of the tibia. Lower cortical bone integrity in DMPA users was possibly mediated by increased intracortical remodelling, but trabecular bone was not affected by contraceptive use.

Ultrasonic Guided Waves in Bone: A Decade of Advancement in Review

The use of guided wave ultrasonography as a means to assess cortical bone quality has been a significant practice in bone quantitative ultrasound for more than 20 years. In this article, the key developments within the technology of ultrasonic guided waves (UGW) in long bones during the past decade are documented. The covered topics include data acquisition configurations available for measuring bone guided waveforms, signal processing techniques applied to bone UGW, numerical modeling of ultrasonic wave propagation in cortical long bones, formulation of inverse approaches to extract bone properties from observed ultrasonic signals, and clinical studies to establish the technology's application and efficacy. The review concludes by highlighting specific challenging problems and future research directions. In general, the primary purpose of this work is to provide a comprehensive overview of bone guided-wave ultrasound, especially for newcomers to this scientific field.

Osteosarcopenic obesity and its components-osteoporosis, sarcopenia, and obesity-are associated with blood cell count-derived inflammation indices in older Chinese people

Background

The aim of this study was to investigate the associations of osteosarcopenic obesity (OSO) and its components with complete blood cell count-derived inflammation indices.

Methods

In this cross-sectional study, data of 648 participants aged ≥60 years (men/women: 232/416, mean age: 67.21 ± 6.40 years) were collected from January 2018 to December 2020. Areal bone mineral density and body fat percentage were used to define osteopenia/osteoporosis and obesity, respectively. The criteria of the 2019 Asian Working Group for Sarcopenia were used to diagnose sarcopenia. Based on the number of these conditions, participants were divided into four groups: OSO/0, OSO/1, OSO/2, and OSO/3. Logistic regression analysis was conducted to identify associations between blood cell count-derived inflammation indices and the number of disorders with abnormal body composition.

Results

Systemic inflammation response index (SIRI), white blood cells, neutrophil-to-lymphocyte ratio (NLR), aggregate inflammation systemic index (AISI), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) showed statistically significant differences among the four groups (P < 0.05). Unlike in the OSO/0 group, in all other groups, AISI, SIRI, PLR, and NLR were significantly associated with increased likelihood of having multiple disorders with abnormal body composition after adjustment for confounders (P < 0.0001 for all). However, LMR showed an inverse correlation with the number of these conditions (P < 0.05).

Conclusion

Higher SIRI, AISI, NLR, and PLR values and lower LMR values are closely associated with OSO and its individual components—osteoporosis, sarcopenia, and obesity—in older adults, suggesting that the value of these indices in the evaluation of OSO warrants further investigation.

Prospective comparative study of quantitative X-ray (QXR) versus dual energy X-ray absorptiometry to determine the performance of QXR as a predictor of bone health for adult patients in secondary care

OBJECTIVES

To evaluate a method of quantitative X-ray (QXR) for obtaining bone health information from standard radiographs aimed at identifying early signs of osteoporosis to enable improved referral and treatment. This QXR measurement is performed by postexposure analysis of standard radiographs, meaning bone health data can be acquired opportunistically, alongside routine imaging.

DESIGN

The relationship between QXR and dual energy X-ray absorptiometry (DEXA) was demonstrated with a phantom study. A prospective clinical study was conducted to establish areal bone mineral density (aBMD) prediction model and a risk prediction model of a non-normal DEXA outcome. This was then extrapolated to a larger patient group with DEXA referral data.

SETTING

Secondary care National Health Service Hospital.

PARTICIPANTS

126 consenting adult patients from a DEXA clinic.

INTERVENTIONS

All participants underwent a DEXA scan to determine BMD at the lumbar spine (L2-L4) and both hips. An additional Antero-Posterior pelvis X-ray on a Siemens Ysio, fixed digital radiograph system was performed for the study.

OUTCOME

Performance of QXR as a risk predictor for non-normal (osteoporotic) BMD.

RESULTS

Interim clinical study data from 78 patients confirmed a receiver operator curve (area under the ROC curve) of 0.893 (95% CI 0.843 to 0.942) for a risk prediction model of non-normal DEXA outcome. Extrapolation of these results to a larger patient group of 11 029 patients indicated a positive predictive value of 0.98 (sensitivity of 0.8) for a population of patients referred to DEXA under current clinical referral criteria.

CONCLUSIONS

This study confirms that the novel QXR method provides accurate prediction of a DEXA outcome.

TRIAL REGISTRATION NUMBER

ISRCTN98160454; Pre-results.

Association between non-Caucasian-specific ASCC1 gene polymorphism and osteoporosis and obesity in Korean postmenopausal women

INTRODUCTION

Osteoporosis is a common disorder characterized by decreased bone mineral density (BMD). Interestingly, osteoporosis and obesity have several similar features, including a genetic predisposition and a common bone marrow stem cell. With aging, the composition of bone marrow shifts to adipocytes, osteoclast activity increases, and osteoblast function declines, resulting in osteoporosis.

MATERIALS AND METHODS

We performed a genome-wide association study (GWAS) analysis with osteoporosis and body mass index (BMI) and did identify an association in 349 and 384 SNPs by filtering with the significant p values (p < 0.001) of BMI and osteoporosis, respectively.

RESULTS

Only three of those SNPs were common (rs2326365, rs7097028, and rs11000205) between the SNPs significantly associated with BMI and/or osteoporosis in Korean Association REsource (KARE) females. Two of the three SNPs belonged to the ASCC1 gene and one to the FAM50B gene. We carried out a minor allele frequency (MAF) analysis of the rs7097028 and rs11000205 SNPs in the ASCC1 gene with a geographic genome variant browser. Both rs7097028 and rs11000205 in the ASCC1 gene were seen mostly in African and Southeast Asian populations.

CONCLUSIONS

Our results suggest that the ASCC1 gene is a significant genetic factor for determining the risk for both osteoporosis and obesity in KARE postmenopausal females.

Can low-frequency guided waves at the tibia paired with machine learning differentiate between healthy and osteopenic/osteoporotic subjects? A pilot study

PURPOSE

Axial transmission quantitative acoustics (ax-QA) has shown to be a promising tool for assessing bone health and properties in a safe, inexpensive, and portable manner. This study investigated the efficacy of low-frequency ax-QA measured at the tibia, paired with a support vector machine (SVM) approach for combining multiple acoustic indicators, to diagnose osteoporosis as defined by bone mineral density.

METHODS

This pilot study measured 41 female subjects using ax-QA (flexural mode, 3 kHz) at the tibia and using dual X-ray absorptiometry (DXA) at the lumbar spine, femoral neck, and distal radius. For each location, a threshold classifier and SVM were trained to differentiate between healthy and non-healthy subjects based on the phase velocity at different frequencies. Receiver Operating Characteristics and area under curve values (AUC) were used to assess the classifiers' performances for various thresholds and class-weights.

RESULTS

The SVM outperformed the threshold classifier for all three bone locations at low false positive rates. While differentiation between healthy and non-healthy bone states was poor for the spine (AUC: 0.56 ± 0.04), good to moderate performances were observed for the radius (AUC: 0.83 ± 0.03) and hip (AUC: 0.71 ± 0.04).

CONCLUSIONS

Low-frequency ax-QA has demonstrated potential for complementing DXA in screening for osteoporosis at the radius and hip. Through further addition of acoustic indicators ax-QA could provide a diagnostic alternative in third-world countries, and bring bone health screening and monitoring into the hands of clinicians and general health practitioners everywhere.

Weak cation exchange magnetic beads coupled with matrix-assisted laser desorption ionization-time of flight-mass spectrometry in screening serum protein markers in osteopenia

The present study aimed at investigating the weak cation magnetic separation technology and matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) in screening serum protein markers of osteopenia from ten postmenopausal women and ten postmenopausal women without osteopenia as control group, to find a new method for screening biomarkers and establishing a diagnostic model for primary type I osteoporosis. Serum samples were collected from postmenopausal women with osteopenia and postmenopausal women with normal bone mass. Proteins were extracted from serum samples by weak cation exchange magnetic beads technology, and mass spectra acquisition was done by MALDI-TOF-MS. The visualization and comparison of data sets, statistical peak evaluation, model recognition, and discovery of biomarker candidates were handled by the proteinchip data analysis system software(ZJU-PDAS). The diagnostic models were established using genetic arithmetic based support vector machine (SVM). The SVM result with the highest Youden Index was selected as the model. Combinatorial Peaks having the highest accuracy in distinguishing different samples were selected as potential biomarker. From the two group serum samples, a total of 133 differential features were selected. Ten features with significant intensity differences were screened. In the pair-wise comparisons, processing of MALDI-TOF spectra resulted in the identification of ten differential features between postmenopausal women with osteopenia and postmenopausal women with normal bone mass. The difference of features by Youden index showed that the highest features had a mass to charge ratio of 1699 and 3038 Da. A diagnosis model was established with these two peaks as the candidate marker, and the specificity of the model is 100 %, the sensitivity was 90 % by leave-one-out cross validation test. The two groups of specimens in SVM results on the scatter plot could be clearly distinguished. The peak with m/z 3038 in the SVM model was suggested as Secretin by TagIdent tool. To provide further validation, the secretin levels in serum were analyzed using enzyme-linked immunosorbent assays that is a competitive inhibition enzyme immunoassay technique for the in vitro quantitative measurement of secretin in human serum.

Association of the I264T variant in the sulfide quinone reductase-like (SQRDL) gene with osteoporosis in Korean postmenopausal women

To identify novel susceptibility variants for osteoporosis in Korean postmenopausal women, we performed a genome-wide association analysis of 1180 nonsynonymous single nucleotide polymorphisms (nsSNPs) in 405 individuals with osteoporosis and 722 normal controls of the Korean Association Resource cohort. A logistic regression analysis revealed 72 nsSNPs that showed a significant association with osteoporosis (p<0.05). The top 10 nsSNPs showing the lowest p-values (p = 5.2×10-4-8.5×10-3) were further studied to investigate their effects at the protein level. Based on the results of an in silico prediction of the protein's functional effect based on amino acid alterations and a sequence conservation evaluation of the amino acid residues at the positions of the nsSNPs among orthologues, we selected one nsSNP in the SQRDL gene (rs1044032, SQRDL I264T) as a meaningful genetic variant associated with postmenopausal osteoporosis. To assess whether the SQRDL I264T variant played a functional role in the pathogenesis of osteoporosis, we examined the in vitro effect of the nsSNP on bone remodeling. Overexpression of the SQRDL I264T variant in the preosteoblast MC3T3-E1 cells significantly increased alkaline phosphatase activity, mineralization, and the mRNA expression of osteoblastogenesis markers, Runx2, Sp7, and Bglap genes, whereas the SQRDL wild type had no effect or a negative effect on osteoblast differentiation. Overexpression of the SQRDL I264T variant did not affect osteoclast differentiation of the primary-cultured monocytes. The known effects of hydrogen sulfide (H2S) on bone remodeling may explain the findings of the current study, which demonstrated the functional role of the H2S-catalyzing enzyme SQRDL I264T variant in osteoblast differentiation. In conclusion, the results of the statistical and experimental analyses indicate that the SQRDL I264T nsSNP may be a significant susceptibility variant for osteoporosis in Korean postmenopausal women that is involved in osteoblast differentiation.

Quantitative ultrasound measurements of the calcaneus and hand phalanges in elderly Spanish men: relationship with peripheral bone mineral density of the hand phalanges

OBJECTIVES

The aims of this pilot study were to describe quantitative ultrasound (US) measurements and peripheral bone mineral density (BMD) of the hand phalanges on dual-energy x-ray absorptiometry and to examine the correlations between them in elderly Spanish men.

METHODS

We studied 199 healthy men (mean age ± SD, 73.31 ± 5.10 years). The participants were not taking any medications, and they reported no diseases, including diseases that are associated with abnormalities in mineral metabolism. Phalangeal and calcaneal quantitative US measurements and phalangeal BMD measurements were performed in all participants.

RESULTS

A bivariate correlation analysis showed no association between quantitative US assessments at the phalanges or the calcaneus (P = .409). After adjustment for potential confounders, the correlation between phalangeal BMD and phalangeal quantitative US measurements was r = 0.417 (P < .0001), and the correlation for calcaneal quantitative US was r = 0.26 (P = .001). Further adjustment by percentage of body fat increased quantitative US correlations with phalangeal BMD: r = 0.450 (P < .0001) at the phalanges; r = 0.291 (P = .001) at the calcaneus.

CONCLUSIONS

There is a small correlation between quantitative US measurements at the calcaneus and phalangeal BMD that increases to a moderate level with quantitative US measurements at the phalanges in elderly Spanish men.

The preliminary evaluation of a 1 MHz ultrasound probe for measuring the elastic anisotropy of human cortical bone

Our objective is to evaluate an ultrasound probe for measurements of velocity and anisotropy in human cortical bone (tibia). The anisotropy of cortical bone is a known and mechanically relevant property in the context of osteoporotic fracture risk. Current in vivo quantitative ultrasound devices measuring the velocity of ultrasound in long bones can only be applied in the axial direction. For anisotropy measurements a second direction for velocity measurements preferably perpendicular to the axial direction is necessary. We developed a new ultrasound probe which permits axial transmission measurements with a simultaneous second perpendicular direction (tangential). Anisotropy measurements were performed on isotropic and anisotropic phantoms and two excised human female tibiae (age 63 and 82). Anisotropy ratios (AI; ratio of squared ultrasound velocities in the two directions) were for the isotropic phantom 1.06 ± 0.01 and for the anisotropic phantom 1.14 ± 0.03 (mean ± standard deviation). AI was 1.83 ± 0.29 in the tibia from the older donor and 1.37 ± 0.18 in the tibia from the younger donor. The AIs were in the expected range and differed significantly (p<0.05, t-test) between the tibiae. Measured sound velocities were reproducible (mean standard deviation of short time precision of both channels for phantom measurements 31 m/s) and in agreement with reported velocities of the phantom material. Our results document the feasibility of anisotropy measurements at long bones using a single probe. Further improvements in the design of the probe and tests in vivo are warranted. If this approach can be evaluated in vivo an additional tool for assessing the bone status is available for clinical use.

Multisite quantitative ultrasound for the prediction of fractures over 5 years of follow-up: the Canadian Multicentre Osteoporosis Study

This study assessed the ability of multisite quantitative ultrasound (mQUS) to predict fracture over a 5-year follow-up. Participants were a subset of the Canadian Multicentre Osteoporosis Study. mQUS-assessed speed of sound (SOS in m/s) at three sites (distal radius, tibia, and phalanx) and extensive questionnaires were completed, after which participants were followed for 5 years and incident fractures recorded. Two survival analyses were completed for each site--a univariate analysis and an adjusted multivariate analysis controlling for age, antiresorptive use, femoral neck bone mineral density, number of diseases, previous fractures, body mass index (BMI), parental history of hip fracture, current smoking, current alcoholic drinks >3 per day, current use of glucocorticoids, and rheumatoid arthritis diagnosis (variables from the FRAX 10-year fracture risk assessment tool). The unit of change for regression analyses was one standard deviation for all measurement sites, specific to site and sex. Separate analyses were completed for all clinical fractures, nonvertebral fractures, and hip fractures by sex. There were 2633 women and 1108 men included, and they experienced 204 incident fractures over 5 years (5.5% fractured). Univariate models revealed statistically significant (p < 0.05) predictive ability of mQUS for all three measurement sites for women alone for all three fracture types (one standard deviation decrease in SOS was associated with a 52% to 130% increase in the risk of fracture), but not for the men's group. The adjusted model found that measures at the distal radius and tibia in the women's group could significantly (p < 0.05) predict all clinical fractures and nonvertebral fractures within the next 5 years (one standard deviation decrease in SOS was associated with a 25% to 31% increase in the risk of fracture). mQUS provided significant 5-year clinical fracture prediction in women, independent of bone mineral density and other significant risk factors for fracture, when measured at the distal radius and tibia sites.

Reducing the need for central dual-energy X-ray absorptiometry in postmenopausal women: efficacy of a clinical algorithm including peripheral densitometry

We evaluated the efficacy of a triage approach based on a combination of osteoporosis risk-assessment tools plus peripheral densitometry to identify low bone density accurately enough to be useful for clinical decision making in postmenopausal women. We conducted a cross-sectional diagnostic study in postmenopausal Caucasian women from primary and tertiary care. All women underwent dual-energy X-ray absorptiometric (DXA) measurement at the hip and lumbar spine and were categorized as osteoporotic or not. Additionally, patients had a nondominant heel densitometry performed with a PIXI densitometer. Four osteoporosis risk scores were tested: SCORE, ORAI, OST, and OSIRIS. All measurements were cross-blinded. We estimated the area under the curve (AUC) to predict the DXA results of 16 combinations of PIXI plus risk scores. A formula including the best combination was derived from a regression model and its predictability estimated. We included 505 women, in whom the prevalence of osteoporosis was 20 %, similar in both settings. The best algorithm was a combination of PIXI + OST + SCORE with an AUC of 0.826 (95 % CI 0.782-0.869). The proposed formula is Risk = (-12) × [PIXI + (-5)] × [OST + (-2)] × SCORE and showed little bias in the estimation (0.0016). If the formula had been implemented and the intermediate risk cutoff set at -5 to 20, the system would have saved <euro>4,606.34 in the study year. The formula proposed, derived from previously validated risk scores plus a peripheral bone density measurement, can be used reliably in primary care to avoid unnecessary central DXA measurements in postmenopausal women.

Assessment of the fundamental flexural guided wave in cortical bone by an ultrasonic axial-transmission array transducer

The fundamental flexural guided wave (FFGW), as modeled, for example, by the A0 Lamb mode, is a clinically useful indicator of cortical bone thickness. In the work described in this article, we tested so-called multiridge-based analysis, based on the crazy climber algorithm and short-time Fourier transform, for assessment of the FFGW component recorded by a clinical array transducer featuring a limited number of elements. Methods included numerical finite-element simulations and experiments in bone phantoms and human radius specimens (n = 41). The proposed approach enabled extraction of the FFGW component and determination of its group velocity. This group velocity was in good agreement with theoretical predictions and possessed reasonable sensitivity to cortical width (r(2) = 0.51, p < 0.001) in the in vitro experiments. It is expected that the proposed approach enables related clinical application. Further work is still needed to analyze in more detail the challenges related to the impact of the overlying soft tissue.

Association between the SPRY1 gene polymorphism and obesity-related traits and osteoporosis in Korean women

BACKGROUND

Emerging evidence has revealed a close relationship between obesity and osteoporosis. It was reported recently that conditional knockout of the Spry1 gene in mice adipocytes causes an increase in body fat and a decrease in bone mass, and that these phenotypes are rescued by Spry1 overexpression in adipose tissue. In this study, we investigated whether genetic variation in the human SPRY1 gene is associated with obesity-related phenotypes and/or osteoporosis in humans.

METHODS

We performed a candidate gene association analysis between the four single nucleotide polymorphisms (SNPs) and 14 imputed SNPs in the SPRY1 gene and obesity-related traits and osteoporosis in a Korean women cohort (3013 subjects).

RESULTS

All four SPRY1 gene SNPs were significantly associated with either obesity-related traits or osteoporosis. The TGCC haplotype in the SRPY1 gene showed simultaneous association with an increased risk for obesity-related traits, percentage body fat (p=0.0087) and percentage abdominal fat (p=0.047), and osteoporosis (odds ratio=1.50; p=0.025) in the recessive genetic model.

CONCLUSIONS

Our results support a previous finding in conditional Spry1 gene knockout mice and suggest that the SPRY1 gene is an important genetic factor for determining the risk of both obesity and osteoporosis in humans.

The effect of osteoporosis on residual ridge resorption and masticatory performance in denture wearers

AIM

To compare masticatory performance, masticatory efficiency and residual ridge resorption (RRR) in osteoporotic and non-osteoporotic edentulous subjects after rehabilitation with complete dentures.

METHOD

Thirty subjects fulfilling the inclusion criteria were enrolled from the patients visiting the Department of Prosthodontics for complete denture fabrication. Two groups consisting of control subjects (group I; N = 15) and osteoporotic subjects (group II; N = 15) were formed. Complete dentures satisfying certain criteria were fabricated for both groups. Masticatory performance and efficiency were measured 6 months after denture insertion. Areal measurements were taken on lateral cephalograms before and 6 months after denture fabrication. The data were then computed to analyse differences between groups I and II using SPSS statistical software version 15.0.

RESULTS

Six months after denture fabrication, the masticatory performance and efficiency were significantly higher (p < 0.001) for group I, with a significant decrease in maxillary and mandibular sagittal area seen in both groups. The rate of bone loss was more in group II compared with group I.

CONCLUSION

Greater masticatory function was demonstrated by the non-osteoporotic group, and the rate of RRR was more in the osteoporotic group compared with the normal group. In this pilot study, osteoporosis leads to greater RRR, decreased masticatory performance and efficiency in edentulous subjects 6 months after denture insertion. Screening for osteoporosis is suggested as a routine procedure for all edentulous subjects undergoing rehabilitation. Recall check-ups for osteoporotic patients should be more frequent, and these patients may require more frequent denture remakes.

Quantitative ultrasound and radiographic absorptiometry are associated with vertebral deformity in Japanese Women: the Hizen-Oshima study

We evaluated the ability of heel quantitative ultrasound (QUS) and metacarpal radiographic absorptiometry (RA) to identify subjects with vertebral deformities in Japanese women aged ≥40. Both QUS and RA were associated with vertebral deformities, and the estimated prevalence at each T-score widely varied with age.

INTRODUCTION

Heel QUS and metacarpal RA have been used for screening patients to evaluate risk of osteoporotic fractures. The aim of this study was to evaluate the ability of QUS and RA to identify women with vertebral deformities in 570 Japanese women aged ≥40, and to estimate the prevalence of vertebral deformity at each T-score.

METHODS

Calcaneal QUS and metacarpal RA were performed. Radiographic vertebral deformities were assessed by quantitative morphometry, defined as vertebral heights more than 3 SD below the normal mean.

RESULTS

The receiver operating characteristic analysis showed that both calcaneal stiffness index (SI) and metacarpal bone mineral density (BMD) were associated with vertebral deformities. Using the T-score of -2.5 as a cutoff value, the specificity and sensitivity for identifying individuals with vertebral deformities was 65% and 83% for calcaneal SI, and 40% and 88% for metacarpal BMD, respectively. The prevalence of vertebral deformity was estimated using age-adjusted logistic regression models. Women with calcaneal SI T-score of -2.5 had a 2% estimated probability of vertebral deformity at age 40, and 22% at age 80. For metacarpal BMD T-score of -2.5, estimated probability was less than 1% at age 40, and 27% at age 80.

CONCLUSION

Both calcaneal SI and metacarpal BMD were associated with prevalence of vertebral deformity. Furthermore, the prevalence widely varied with age at any given bone value.

Low-frequency axial ultrasound velocity correlates with bone mineral density and cortical thickness in the radius and tibia in pre- and postmenopausal women

Axial transmission velocity of a low-frequency first arriving signal (V (LF)) was assessed in the radius and tibia of 254 females, and compared to site-matched pQCT measurements. V (LF) best correlated with cortical BMD, but significantly also with subcortical BMD and cortical thickness. Correlations were strongest for the radius in postmenopausal females.

INTRODUCTION

Ultrasonic low-frequency (LF; 0.2-0.4 MHz) axial transmission, based on the first arriving signal (FAS), provides enhanced sensitivity to thickness and endosteal properties of cortical wall of the radius and tibia compared to using higher frequencies (e.g., 1 MHz). This improved sensitivity of the LF approach has not yet been clearly confirmed by an in vivo study on adult subjects. The aims of the present study were to evaluate the extent to which LF measurements reflect cortical thickness and bone mineral density, and to assess whether an individual LF measurement can provide a useful estimate for these bone properties.

METHODS

Velocity of the LF FAS (V (LF)) was assessed in the radius and tibia shaft by a new ultrasonometer (CV(RMS) = 0.5%) in a cross-sectional study involving 159 premenopausal (20-58 years) and 95 postmenopausal females (45-88 years). Site-matched volumetric total bone mineral density (BMD), cortical bone mineral density (CBMD), subcortical bone mineral density (ScBMD) and cortical thickness (CTh) were assessed using pQCT.

RESULTS

For the postmenopausal females, V (LF) correlated best with CBMD in the radius (R = 0.850, p < 0.001), but significantly also with ScBMD and CTh (R = 0.759 and R = 0.761, respectively; p < 0.001). Similar trends but weaker correlations were observed for the tibia and for the premenopausal women.

CONCLUSIONS

The LF assessment, with an optimal excitation frequency, thus provided good prediction of both cortical thickness and subcortical bone material properties. These results suggest that the LF approach does indeed have enhanced sensitivity for detecting osteoporotic changes that occur deep in the endosteal bone.

Identifying elderly women with osteoporosis by spinal dual X-ray absorptiometry, calcaneal quantitative ultrasound and spinal quantitative computed tomography: a comparative study

The ability of spinal dual x-ray absorptiometry (DXA), calcaneal quantitative ultrasound (QUS) and spinal quantitative computed tomography (QCT) to identify women with osteoporosis within the GISELA study was evaluated in 43 women, aged 62-87 years. Osteoporosis was defined as a T-score below or equal to -2.5 using DXA (femoral neck). To determine the performance of each method, the sensitivity, specificity and area under the curve (by means of a receiver operating characteristic [ROC] analysis) were calculated. The median T-scores from the measurements differed significantly (p < 0.0001). DXA (spine) identified 75% of women with osteoporosis; QUS and QCT identified 100%. The specificity was 89% for DXA (spine), 66% for QUS and 29% for QCT. ROC analysis showed that all three methods are qualified to identify women with osteoporosis; however, the different sensitivities and specificities of the methods, as well as the thresholds used for diagnosing osteoporosis have to be considered.

Quantitative ultrasound in the management of osteoporosis: the 2007 ISCD Official Positions

Dual-energy X-ray absorptiometry (DXA) is commonly used in the care of patients for diagnostic classification of osteoporosis, low bone mass (osteopenia), or normal bone density; assessment of fracture risk; and monitoring changes in bone density over time. The development of other technologies for the evaluation of skeletal health has been associated with uncertainties regarding their applications in clinical practice. Quantitative ultrasound (QUS), a technology for measuring properties of bone at peripheral skeletal sites, is more portable and less expensive than DXA, without the use of ionizing radiation. The proliferation of QUS devices that are technologically diverse, measuring and reporting variable bone parameters in different ways, examining different skeletal sites, and having differing levels of validating data for association with DXA-measured bone density and fracture risk, has created many challenges in applying QUS for use in clinical practice. The International Society for Clinical Densitometry (ISCD) 2007 Position Development Conference (PDC) addressed clinical applications of QUS for fracture risk assessment, diagnosis of osteoporosis, treatment initiation, monitoring of treatment, and quality assurance/quality control. The ISCD Official Positions on QUS resulting from this PDC, the rationale for their establishment, and recommendations for further study are presented here.

The clinical use of quantitative ultrasound (QUS) in the detection and management of osteoporosis

For the detection and management of osteoporosis and osteoporosis-related fractures, quantitative ultrasound (QUS) is emerging as a relatively low-cost and readily accessible alternative to dual-energy X-ray absorptiometry (DXA) measurement of bone mineral density (BMD) in certain circumstances. The following is a brief, but thorough review of the existing literature with respect to the use of QUS in 6 settings: 1) assessing fragility fracture risk; 2) diagnosing osteoporosis; 3) initiating osteoporosis treatment; 4) monitoring osteoporosis treatment; 5) osteoporosis case finding; and 6) quality assurance and control. Many QUS devices exist that are quite different with respect to the parameters they measure and the strength of empirical evidence supporting their use. In general, heel QUS appears to be most tested and most effective. Overall, some, but not all, heel QUS devices are effective assessing fracture risk in some, but not all, populations, the evidence being strongest for Caucasian females over 55 years old. Otherwise, the evidence is fair with respect to certain devices allowing for the accurate diagnosis of likelihood of osteoporosis, and generally fair to poor in terms of QUS use when initiating or monitoring osteoporosis treatment. A reasonable protocol is proposed herein for case-finding purposes, which relies on a combined assessment of clinical risk factors (CR.F) and heel QUS. Finally, several recommendations are made for quality assurance and control.

Ultrasonic guided waves in bone

Recent progress in quantitative ultrasound (QUS) has shown increasing interest toward measuring long bones by ultrasonic guided waves. This technology is widely used in the field of nondestructive testing and evaluation of different waveguide structures. Cortical bone provides such an elastic waveguide and its ability to sustain loading and resist fractures is known to be related to its mechanical properties at different length scales. Because guided waves could yield diverse characterizations of the bone's mechanical properties at the macroscopic level, the method of guided waves has a strong potential over the standardized bone densitometry as a tool for bone assessment. Despite this, development of guided wave methods is challenging, e.g., due to interferences and multiparametric inversion problems. This paper discusses the promises and challenges related to bone characterization by ultrasonic guided waves.

Mechanical analysis of percutaneous sacroplasty using CT image based finite element models

Sacral insufficiency fractures are an under-diagnosed source of acute lower back pain. A polymethylmethacrylate (PMMA) cement injection procedure called sacroplasty has recently been utilized as a treatment for sacral insufficiency fractures. It is believed that injection of cement reduces fracture micromotion, thus relieving pain. In this study, finite element models were used to examine the mechanical effects of sacroplasty. Finite element models were constructed from CT images of two cadavers on which sacroplasties were performed. The images were used to create the mesh geometry, and to apply non-homogeneous material properties to the models. Models were created representing the case with and without cement, thus simulating the pre- and post-sacroplasty situation. The results indicate that the sacrum has a 3D multi-axial state of strain. While compressive strains were the largest, tensile and shear strains were significant as well. Cement in the sacrum reduced strains 40-60% locally around the cement. However, overall model stiffness only increased 1-4%. This indicates that the effects of sacroplasty are primarily local.

What is the role of DXA, QUS and bone markers in fracture prediction, treatment allocation and monitoring?

There is evidence that treatment can decrease the risk of fractures in osteoporotic patients, and screening of these patients is therefore relevant. Diagnosis of osteoporosis is based on the T-score calculated from bone mineral density (BMD) measurements. BMD measurements have been widely used for the management of osteoporosis, and a low BMD is a strong risk factor for fractures. But BMD measurement has several limitations in both diagnosis, prediction of fracture risk, and treatment follow-up. Quantitative ultrasound (QUS) parameters, an alternative to BMD in the assessment of bone, are independent risk factors for osteoporotic fracture. However, the use of QUS cannot be recommended for both allocation and monitoring of treatment. Biochemical markers of bone remodelling can be useful for both prediction of fracture risk and monitoring of treatment if sources of variability are controlled.

Quantitative ultrasound of the calcaneus in a Korean population: reference data and relationship to bone mineral density determined by peripheral dual X-ray absorptiometry

The aim of this study was to establish reference data for the quantitative ultrasound (QUS) of the calcaneus and for the bone mineral densities (BMD) of the calcaneus and distal forearm, and to evaluate the correlation between QUS parameters and BMD in a Korean population. We performed a cross-sectional study involving 3,053 subjects (1,225 men and 1,828 women). QUS was conducted on the calcaneus and was quantified as speed of sound (SOS, m/sec), broadband ultrasound attenuation (BUA, dB/MHz), and stiffness index. The BMD of the calcaneus and distal forearm were measured using dual X-ray absorptiometry. The peak mean values for the QUS parameters occurred in the 20 to 29-yr-old subjects of both sexes, with the exception of the BUA, which reached the highest values in women of 30-39 yr. For both sexes, the mean BMD of the calcaneus was highest in those 20-29 yr old and that of the distal forearm was highest in those 40-49 yr old. The correlations between the QUS and BMD results were found to be 0.41 to 0.73 in men and 0.51 to 0.76 in women. Theses data can serve as a reference values for both sexes in Korea.

Comparison of questionnaire and quantitative ultrasound techniques as screening tools for DXA

The aim of the study is to assess the sensitivity and specificity of different techniques and their ability to act as screening tools in relation to dual energy X-ray absorptiometry (DXA) in a group of 208 postmenopausal women. In this study we examined eight screening systems for the diagnosis of osteoporosis, the osteoporosis self-assessment tool (OST), the osteoporosis risk assessment instrument (ORAI), the osteoporosis index of risk (OSIRIS), a risk index derived using data from the study of osteoporotic fractures (SOFSURF), the simple calculated osteoporosis risk estimation (SCORE), patient body weight (pBW), along with two ultrasound based systems, the Sunlight Omnisense (Sunlight Medical, Rehovot, Israel) and the CUBA Clinical (McCue plc, Winchester, UK). The sensitivity and specificity of the different techniques in relation to DXA were plotted as receiver-operating characteristic (ROC) curves at three different levels (DXA T-score -2.5 osteoporosis, -2 and -1 osteopenia). The areas under the curves (AUC) were calculated and showed broadband ultrasound attenuation (BUA) at the calcaneus to provide consistently the highest AUC (0.77-0.81). The velocity of sound (VOS) of the calcaneus (AUC=0.72-0.76) was equally good, but was out-performed by some of the questionnaire systems (AUC=0.66-0.79). Both the questionnaire systems and the CUBA Clinical out-perform the Sunlight Omnisense (AUC=0.58-0.7), which showed comparable performance with body weight (AUC=0.66-0.69). The results show that QUS is capable of selecting patients with low bone density as measured by DXA. A patient displaying a low QUS value should be followed up with a DXA scan to confirm the diagnosis.

Dual X-ray absorptiometry: clinical evaluation of a new cone-beam system

The DMS Lexxos is the first cone-beam dual X-ray absorptiometry (DXA) system capable of performing bone mineral density (BMD) measurements of the spine and hip. By using a two-dimensional (2-D) detector array rather than the linear array used with conventional fan-beam DXA systems, image acquisition time on Lexxos is only 1.5 s. However, the need to correct for the large signal from scattered radiation reaching the detector is a potential source of error in cone-beam DXA. The aim of this clinical evaluation of the Lexxos bone densitometer was to investigate the relative accuracy of cone-beam BMD measurements compared with conventional DXA by performing an in vivo cross-calibration study with an established fan-beam system, the Hologic QDR-4500. Spine (L1-L4) and hip BMD measurements were performed in 135 patients (111 women, 24 men) referred for a bone densitometry examination. Duplicate Lexxos measurements were performed in 27 female patients to evaluate precision. On average, Lexxos spine and femoral neck BMD measurements were 2% lower than those on the QDR-4500, whereas total hip BMD was 5% higher. Larger differences were found for the trochanter and Ward's triangle regions. For all sites, Lexxos BMD measurements showed a strong linear relationship with those measured on the QDR-4500 with correlation coefficients in the range r = 0.95 to 0.97 for the clinically important spine, femoral neck, and total hip regions. The root mean standard error (RMSE) between Lexxos and QDR-4500 BMDs ranged from 0.037 g/cm(2) for the femoral neck to 0.060 g/cm(2) for the spine, whereas Lexxos precision was 1.3% for total hip, 2.0% for femoral neck, and 2.3% for spine BMD. Although for the hip BMD sites the RMSE and precision of Lexxos measurements were similar to studies of pencil-beam and fan-beam DXA systems, the results for the spine were poorer than expected. The findings of this study suggest that Lexxos corrects accurately for the effects of scattered radiation at the detector, but that the precision of spine BMD measurements may be limited by involuntary patient movement between the high and low energy X-ray exposures.