The usefulness of quantitative ultrasound at the hand phalanges in the detection of the different types of nontraumatic fractures

Quantitative Ultrasound (QUS) in the Management of Osteoporosis and Assessment of Fracture Risk: An Update

Quantitative ultrasound (QUS) presents a low cost and readily available alternative to DXA measurements of bone mineral density (BMD) for osteoporotic fracture risk assessment. It is performed in a variety of skeletal sites, among which the most widely investigated and clinically used are first the calcaneus and then the radius. Nevertheless, there is still uncertainty in the incorporation of QUS in the clinical management of osteoporosis as the level of clinical validation differs substantially upon the QUS models available. In fact, results from a given QUS device can unlikely be extrapolated to another one, given the technological differences between QUS devices. The use of QUS in clinical routine to identify individuals at low or high risk of fracture could be considered primarily when central DXA is not easily available. In this later case, it is recommended that QUS bone parameters are used in combination with established clinical risk factors for fracture. Currently, stand-alone QUS is not recommended for treatment initiation decision making or follow-up. As WHO classification of osteoporosis thresholds cannot apply to QUS, thresholds specific for given QUS devices and parameters need to be determined and cross-validated widely to have a well-defined and certain use of QUS in osteoporosis clinical workflow. Despite the acknowledged current clinical limitations for QUS to be used more widely in daily routine, substantial progresses have been made and new results are promising.

Skeletal Status in Women With Carpal Tunnel Syndrome-A 1-Yr Prospective Study

Functional deterioration due to carpal tunnel syndrome (CTS) may influence the bone status of the forearm and hand. The aim of this prospective study was to establish whether CTS has an impact on bone status at distal parts of the upper limb and to monitor the longitudinal changes of that status during a 1-yr follow-up after surgical treatment. Fifteen women with CTS at mean age of 55.13 ± 9.3 yr, mean weight of 79.18 ± 20.37 kg, and mean height of 157.8 ± 6.17 cm were enrolled into the study. All women had unilateral CTS that negatively affected upper limb function and were qualified to surgical treatment. Functional status was established at baseline using Levine's scale, motor latency, and nerve conduction velocity in electrophysiologic examinations. Bone status was established using densitometric measurements (Hologic Explorer, Bedford, MA) at the forearm, spine, and hip (bone mineral density [BMD], g/cm²) and with quantitative ultrasound measurements (amplitude-dependent speed of sound, m/s) at hand phalanges (DBM Sonic, IGEA, Carpi, Italy). Longitudinal changes were established for Levine's scale score and for forearm and phalanges measurements at 3, 6, and 12 mo after surgery. Levine's scale results improved significantly over a period of observation (p < 0.0001). Longitudinal BMD measurements for ultradistal forearm have shown a decrease only for measurement at 6 mo vs baseline result (0.386 ± 0.08 g/cm² vs 0.375 ± 0.08 g/cm², p < 0.05) with onward increase. Amplitude-dependent speed of sound did not differ over the period of observation. Correlation analysis has shown that functional status expressed by Levine's scale was most strongly related to the longitudinal BMD measurements for ultradistal forearm at 6 mo (r = -0.52, p < 0.05). Successful surgery in patients with CTS does not lead to permanent deterioration in bone status within the affected upper limb in a 1-yr longitudinal observation.

Quantitative Ultrasound (QUS) in the Management of Osteoporosis and Assessment of Fracture Risk

The use of quantitative ultrasound (QUS) for a variety of skeletal sites, associated with the absence of technology-specific guidelines, has created uncertainty with respect to the application of QUS results to the management of individual patients in clinical practice. However, when prospectively validated (this is not the case for all QUS devices and skeletal sites), QUS is a proven, low-cost, and readily accessible alternative to dual-energy X-ray absorptiometry (DXA) measurements of bone mineral density (BMD) for the assessment of fracture risk. Indeed, the clinical use of QUS to identify subjects at low or high risk of osteoporotic fracture should be considered when central DXA is unavailable. Furthermore, the use of QUS in conjunction with clinical risk factors (CRF),allows for the identification of subjects who have a low and high probability of osteoporotic fracture. Device- and parameter-specific thresholds should be developed and cross-validated to confirm the concurrent use of QUS and CRF for the institution of pharmacological therapy and monitoring therapy.

Quantitative ultrasound bone measurements in pre-pubertal children with type 1 diabetes

This case-control study aimed to assess bone status in children with type 1 diabetes mellitus (T1DM). Fifty-seven pre-pubertal patients (37 boys, aged 7.9 ± 2.5 years, T1DM duration 3.1 ± 1.6 years) and 171 age-matched healthy controls (111 boys) were studied. Quantitative ultrasound (QUS) was used to measure amplitude dependent speed of sound (Ad-SoS) at hand phalanges (expressed as standard deviation score [SDS]). Anthropometric and disease-related data (including mean HbA(1c) from whole T1DM duration [T], last year [Y], examination day [D]) were collected. Mean Ad-SoS SDS in patients -0.13 ± 1.32 (95% confidence interval [CI] -0.48, 0.22) was similar to that of controls. Subgroups discriminated according to HbA(1c) D, Y and T (cut-off 7.0%) did not differ regarding analyzed parameters. In patients, Ad-SoS SDS was comparable for both genders. Multivariable stepwise regression analysis showed significant negative influence of diabetes duration on Ad-SoS SDS. QUS findings in pre-pubertal children with T1DM do not differ from those in healthy children. Disease duration seems to affect negatively Ad-SoS SDS. However, independent prospective studies are needed to elucidate the true associations.

Phalangeal quantitative ultrasound in 1,719 children and adolescents with bone disorders

SUMMARY

We measured bone properties by phalangeal quantitative ultrasound in 1,719 pediatric patients with bone disorders, classifying them according to fracture status. Quantitative ultrasound discriminated fractured and nonfractured pediatric patients and enabled us to stratify fractured patients into classes according to the severity of the causative trauma (spontaneous, minimal trauma, appropriate trauma fractures).

INTRODUCTION

The correlation between quantitative bone measurements and fractures is poorly established in pediatric patients with bone disorders. We correlated phalangeal quantitative ultrasound (QUS) and fracture history in children and adolescents with bone disorders and evaluated the ability of QUS to recognize fractured patients.

METHODS

Amplitude-dependent speed of sound (AD-SoS) and bone transmission time (BTT) were measured in 1,719 pediatric patients with bone disorders and related to fracture history. The patients were classified as (1) spontaneously (77), (2) minimal trauma (101), or (3) appropriate trauma fractured (206), and (4) nonfractured (1,335). The likelihood of fracture according to QUS was calculated as odds ratio per SD decrease (OR/SD), and the effectiveness in discriminating fractured patients was evaluated by receiver operating characteristic (ROC) analysis. The influence of age, sex, puberty, height, and BMI was explored by respective adjustments and multiple logistic regression.

RESULTS

Fractured patients showed significantly reduced AD-SoS and BTT standard deviation score (-0.32 ± 1.54 and -0.78 ± 1.49) compared to nonfractured subjects (0.43 ± 1.63 and -0.11 ± 1.34). QUS measurements paralleled the causative trauma severity, ranging from the lowest values in spontaneously fractured patients to normal values in appropriate trauma fractured subjects. The OR/SD were increasingly higher in appropriate trauma fractured, minimal trauma fractured, and spontaneously fractured patients. At ROC analysis, both parameters proved to have significant discrimination power in recognizing spontaneously and minimal trauma-fractured patients.

CONCLUSIONS

QUS identifies fractured pediatric patients with bone disorders, reflecting the severity of the causative trauma with a high discrimination power for fragility fractures.

Defining cut-off values for the diagnosis of osteoporosis in postmenopausal women by quantitative ultrasonography of the phalanx

AIM

Quantitative ultrasound (QUS) of the phalanx is a non-invasive, inexpensive and portable method for bone assessment. We determined a cut off point for it in the diagnosis of osteoporosis.

METHODS

In 180 postmenopausal women, dual-energy X-ray absorptiometry (DEXA) of the spine and femur and QUS of the phalanx were performed. Then, the optimum cut-off point for QUS was determined.

RESULTS

Osteoporosis was found in 28.8% of women by DEXA (18.3% in L2-L4, 3.9-7.8% in different regions of the femur) and in 28.9% by QUS. Agreement of the methods (kappa value) was 0.317 for spine and 0.036-0.068 for femoral regions. Using receiver-operating characteristic (ROC) curves, we found T-score of -2.0 as the optimum cut-off point of QUS in diagnosing osteoporosis in the spine (sensitivity and specificity were 78.8% and 55.9%, respectively). We did not find a cut-off point for femoral regions because the 95% confidence interval of the area under the ROC curve contained the diagonal line (p = 0.150, 0.179 and 0.05 for femoral neck, trochanter and total femur, respectively). We defined -2.5 as the other T-score cut-off point under these different conditions; more specificity is needed.

CONCLUSION

Agreement was weak to moderate between the two methods. Thus QUS of the phalanx is not a good replacement for DEXA in defining osteoporosis, but it may be used as a screening method.

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.

Seven-year follow-up in a case of primary hyperparathyroidism using quantitative ultrasound and dual X-ray absorptiometry

We have previously reported a case of a 36-year-old woman who was diagnosed with primary hyperparathyroidism following initial skeletal abnormalities in the hand phalanges and calcaneus revealed by quantitative ultrasound (QUS). Successful parathyroid adenoma surgery resulted in progressive increase of bone mineral density and QUS parameters within 6 months, 1 year and 2 years of follow-up. Now, 5 years after the last measurement and at the onset of her menopause, the study was repeated. It has shown further increase in some ultrasonic and densitometric parameters but decrease in others. This discrepancy could be associated with the early influence of perimenopause on trabecular bone. Based on the current report one can conclude that peripheral QUS used on the hand phalanges and calcaneus is a useful tool for the diagnosis and monitoring of skeletal alterations due to parathyroid dysfunction. Moreover, it can detect early changes associated with perimenopause.

Quantitative ultrasound of phalanges of adults with end-stage renal disease or who have undergone renal transplantation

In patients with end-stage renal disease (ESRD), bone disturbances are common. The aim of this study was to compare the bone mineral status in patients with ESRD, in patients post renal transplantation and in healthy controls. The groups were composed of 218 males and 126 females (ESRD), 43 males and 23 females (renal transplantation) and 614 males and 927 females (healthy controls). Skeletal status was evaluated by quantitative ultrasound measurements of the phalanges using a DBM 1200 (IGEA, Carpi, Italy), which measures the amplitude-dependent speed of sound (Ad-SoS) in m/s. Data analyses were performed with Statistica 6 for Windows (StatSoft, Inc., Tulsa, OK, USA). The Z-scores in gender subgroups were significantly lower in patients undergoing dialysis and after transplantation than in controls (p<0.00001). The Z-scores did not differ between gender subgroups after transplantation and the Z-scores of dialyzed males were significantly better than in females (p<0.00001). The mean value of Z-scores in patients after transplantation was significantly lower than in all patients with ESRD (p<0.05) and in males (p<0.01). The duration of dialysis negatively influenced the Ad-SoS; however, the time elapsed since transplantation did not. The cumulative corticosteroid dose did not correlate with skeletal variables. In conclusion, patients with ESRD treated with hemodialysis and postrenal transplantation patients, across both genders, were observed to have skeletal disturbances.

Phalangeal osteosonogrammetry age-related changes and assessment of a Lebanese reference population

This study was aimed to assess age changes in quantitative ultrasonometry (QUS) of the phalanx in a sample of Lebanese women to determine a reference data for the Lebanese population. Velocity of ultrasound (amplitude-dependent speed of sound; AD-SOS) and the interpretation of the ultra sound signal (ultrasound bone profile index; UBPI) were measured in 211 women with a mean age of 50 years (range 20-79 years) using a DBM sonic Bone profiler device. Women were randomly selected and asked to participate in a nation-wide screening program. Age is an important factor affecting the two parameters: the AD-SOS declines from 2200 m/s at 20 years to 1700 at 80 years. The climacteric condition is another important factor, with significant decrease of the two parameters after the menopause (P<0.0001). This effect is highly influenced by the duration of the postmenopausal period. No influence of weight or height was observed in UBPI variability. The AD-SOS values are similar to those of European population before the age of 50 years. After this age, a significant difference is noted between the two populations. Phalangeal QUS curve of AD-SOS and UBPI are age-dependent. The Lebanese reference curve for AD-SOS is significantly lower from the European curve after the menopause; a 2% decrease in AD-SOS after the age of 50 years can be observed. This decrease in AD-SOS reference values is relevant in the classification of osteoporotic subjects; in fact, if we had used the European reference data set, we had generated 10.9% more Lebanese patients being osteoporotic. Therefore, the use of our standardized reference data reduces the risk of overestimating osteoporosis in the Lebanese population.

Quantitative ultrasound measurements in diabetic and nondiabetic patients with end-stage renal disease

The aim of the study was to assess skeletal status in diabetic and nondiabetic subjects with end-stage renal disease (ESRD). One hundred twenty-three patients with ESRD (57 patients with diabetes: 9 type 1 and 48 type 2) and 66 nondiabetic patients were evaluated. Control group comprised 1541 subjects (614 males and 927 females). Diabetes and/or renal insufficiency was the only reason of bone disease and, in control group, no factors known to influence bone metabolism (chronic diseases or prolonged medications) were noted. Skeletal status was evaluated by quantitative ultrasound measurements at the hand phalanges using DBM 1200 (IGEA, Carpi, Italy), which measures amplitude-dependent speed of sound (Ad-SoS [m/s]). Because of some differences in mean age in subgroups of patients and controls, comparisons were performed using values of Z-score. In all diabetic patients, Z-score was significantly higher compared with nondiabetics (p < 0.05). In all type 1 diabetes patients, Z-score was significantly lower than in all nondiabetic patients (p < 0.05) and in patients with type 2 diabetes (p < 0.001). Z-score was also significantly lower in type 2 diabetics than in nondiabetic females (p < 0.00001) but did not differ in males. Comparisons between Z-scores in controls and patients showed that Z-score in nondiabetic females was significantly lower than in female controls (p < 0.000001), and in nondiabetic males--diabetic type 2 males as well as females--Z-score did not differ vs. results in adequate control group. Z-score was significantly lower in patients with diabetes type 1 vs. all controls (p < 0.001). Correlation analysis showed in all nondiabetic patients that Z-score was negatively affected by duration time of dialysis (r = -0.37, p < 0.01) and parathyroid hormone (PTH) serum level (r = -0.35, p < 0.01). In patients with type 1 diabetes, only PTH influenced significantly Z-score (r = -0.76, p < 0.05) and, in patients with type 2 diabetes, no significant correlations were obtained. Subjects with type 1 diabetes seemed to be sensitive for skeletal disturbances in a course of renal insufficiency, whereas subjects with type 2 diabetes did not show such skeletal pathology as shown by ultrasound measurements at hand phalanges.

Quantitative ultrasound technique at the phalanges in discriminating between uremic and osteoporotic patients

This study was conducted to test the ability of quantitative ultrasound technique (QUS) at the phalanges to discriminate between uremic and osteoporotic patients. Three groups of subjects (38 dialytic women, 16 osteoporotic women with vertebral fractures, 19 non-dialytic and non-fractured women) were recruited at the Department of Radiology at "Casa Sollievo della Sofferenza" Hospital, San Giovanni Rotondo, Italy. The groups were matched for age and body mass index (BMI). On all subjects the following measurements were performed: spinal BMD by QCT and by DXA, Femoral BMD by DXA, phalangeal QUS. For QUS measurements, the DBM Sonic (IGEA, Carpi, Italy) was applied to the metaphysis of the proximal phalanges of the last four fingers of the hand. Osteoporotic women with vertebral fractures showed significantly lower values of spinal BMD by QCT and DXA and Ward's Triangle BMD with respect to hemodialytic patients (p<0.005). All QUS values, except for BTT and SoS, showed lower values in osteoporotic women with respect to hemodialytic patients (p<0.05). Control group showed higher values of AD-SoS, BTT and SoS than hemodialytic patients (p<0.005) while the two groups did not differ for BMD values measured with both QCT and DXA. UBPI and FWA data showed a similar behaviour to DXA and QCT results, whereas BTT and SoS showed a completely different behaviour. AD-SoS was the only parameter that could effectively discriminate among the three groups (ANOVA, p<0.0001). We conclude that phalangeal QUS can discriminate between hemodialysed patients and controls with similar bone mineral density, and can also discriminate between hemodialysed and osteoporotic subjects with vertebral fractures. Different characteristics of ultrasound signal can be ascribed to each bone tissue condition, enabling a clear differentiation of bone tissue changes occurring in menopause, osteoporosis and renal osteodystrophy.

Cross-sectional reference data for phalangeal quantitative ultrasound from early childhood to young-adulthood according to gender, age, skeletal growth, and pubertal development

Bone mineral status by phalangeal quantitative ultrasound (QUS, DBM Sonic, IGEA, Carpi, Modena, Italy) was examined in 3044 (1513 males and 1531 females) healthy subjects, aged 2-21 years. The aim of the study was to provide a reference database for phalangeal QUS parameters, amplitude-dependent speed of sound (AD-SoS) and bone transmission time (BTT), both expressed as centiles and Z score, according to gender, age, height, weight, body mass index (BMI), and pubertal stage to be used for estimating bone mineral status in patients with disorders of growth or of bone and mineral metabolism. In both sexes, AD-SoS and BTT increased significantly (P<0.0001) according to all the anthropometric variables. Females showed higher values than males in the age groups 9-14 for AD-SoS (P<0.04-P<0.0001) and in the age groups 11-13 for BTT (P<0.02). Males had higher BTT values than females in the age groups 6-8 and 15-21 (P<0.04-P<0.0001). AD-SoS was higher (P<0.02-P<0.0001) in females than in males at pubertal stages 2, 3, and 4, but it was higher (P=0.001) in males compared with females at pubertal stage 5. BTT was higher in males than females at pubertal stages 1 (P<0.0001), 2 (P<0.01), and 5 (P<0.0001). In both sexes, AD-SoS and BTT were significantly correlated between them (r=0.92, P<0.0001) and with all the anthropometric variables (r=0.53-r=0.85, P<0.0001). Age, weight, BMI, and pubertal stage were independent predictors of AD-SoS in males; age and pubertal stage were independent predictors of AD-SoS in females. In both sexes, height and pubertal stage, and also age only in females, were independent predictors of BTT. In conclusion, our data show that gender, age, height, and timing of sexual maturation are main determinants of bone structure and geometry, and that both these two processes may be captured by phalangeal QUS. It may be a useful tool to assess bone mineral status from early childhood to young-adulthood with a very small confounding effect related to bone sizes and without exposing the subjects to a source of radiation.

Quantitative ultrasound and peripheral bone densitometry in patients with genetic disorders

The aim of the study was comparison of quantitative ultrasound and densitometric peripheral measurements in subjects with genetic disorders. The study included 52 subjects (35 boys and 17 girls) in mean age 13.1 +/- 4.8 y. Patients with following disorders were evaluated: Down syndrome (n = 21), Martin-Bell syndrome (n = 14) and other (n = 17). There were no additional factors potentially influencing bone metabolism. Bone status was assessed by quantitative ultrasound at the hand phalanges using DBM Sonic 1200 (IGEA, Italy), which measures amplitude-dependent speed of sound (Ad-SoS [m/s]) and bone densitometry at the calcaneus and forearm by the use of PIXI (GE, USA), which measures bone mineral density (BMD, g/cm2). Ad-SoS correlated significantly with forearm and calcaneus BMD in the whole group (r = 0.66, p < 0.000001 and r = 0.51, p < 0.0001, respectively), in females (r = 0.58, p < 0.05 and r = 0.5, p < 0.05) and in males (r = 0.70, p < 0.000001 and r = 0.54, p < 0.001). Calcaneus BMD correlated with wrist BMD in the whole group, in females and males: r = 0.66, p < 0.000001, r = 0.67, p < 0.01 and r = 0.75, p < 0.0001, respectively. These coefficients of correlation were compared and did not reveal significant differences in the whole group and in the gender subgroups. ROC analysis of Ad-SoS values versus calcaneus and forearm BMD showed area under curve 0.89 for forearm BMD and 0.79 for calcaneus BMD (subjects with Ad-SoS T-score below -3.2 were considered as abnormal). Age correlated significantly with Ad-SoS, forearm and calcaneus BMD (r ranged from 0.53 to 0.9, p from 0.05 to 0.000001). In all patients and males, age more strongly influenced Ad-SoS than calcaneus BMD (p < 0.05). Also, body weight and height correlated significantly with Ad-SoS, forearm and calcaneus BMD, except for correlation between forearm BMD and height in female patients (r from 0.58 to 0.84, p < 0.05). Generally, in multiple stepwise regression analysis of age and body size on skeletal parameters, age had positive influence, and body size was a positive or a negative factor. In conclusion, both quantitative ultrasound and peripheral densitometry may be recommended for the assessment of skeletal status in subjects with genetic disorders, although measurements of phalanges seem to be more sensitive for detecting age-related bone changes.

Longitudinal changes in ultrasound measurements: a parallel study in subjects with genetic disorders and healthy controls

Disturbances in skeletal status in subjects with genetic disorder may increase their fracture risk. The aim of the study was longitudinal observation of phalangeal speed of sound changes across the bone over a period of 2 y in 24 patients (14 boys and 10 girls, mean age 9.63 +/- 1.8 y.) and 24 age-matched healthy controls (14 boys and 10 girls, mean age 9.65 +/- 1.71 y.). Weight and height did not differ between patients and controls at baseline and follow-up. Patients with the following disorders were evaluated: 7 with Down syndrome, 6 nonspecific mental retardations of unknown etiology, 5 Martin-Bell syndrome and 6 with other diseases. In patients and controls, no factors potentially influencing bone metabolism (except for genetic disorder) were present. Bone status was assessed by quantitative ultrasound at hand phalanges using DBM Sonic 1200 (IGEA, Carpi, Italy), which measures amplitude-dependent speed of sound (Ad-SoS [m/s]). At baseline, Ad-SoS and Z-score were significantly lower in patients than in controls (1892 +/- 51 m/s versus 1936 +/- 43 m/s, p < 0.01 and -1.47 +/- 1.43 versus -0.14 +/- 1.04, p < 0.001, respectively. In follow-up, Ad-SoS and Z-score increased significantly in patients (1892 +/- 51 m/s to 1934 +/- 48 m/s, p < 0.0001 and -1.47 +/- 1.43 to -0.76 +/- 1.00, p < 0.01, respectively) and in controls (1936 +/- 43 m/s to 1976 +/- 60 m/s and -0.14 +/- 1.04 to 0.31 +/- 1.08, p < 0.05, respectively). Follow-up Ad-SoS and Z-Score were significantly lower in patients (p < 0.01). Longitudinal changes in Ad-SoS, Z-score weight did not differ between patients and control, and height increased more in controls (13.2 +/- 2.8 cm versus 11.4 +/- 5.9 cm, p < 0.05)+). In patients, Ad-SoS increased by 42 m/s (2.22%), and in controls increased by 40 m/s (2.07%). Difference in Ad-SoS between patients and controls was 44 m/s at baseline and 42 m/s at follow-up. Using the value of the least significant change (LSC = 20.5 m/s), in 16 patients (67%) and in 18 controls (75%) Ad-SoS showed an increase greater than the LSC, in one control (4%) a decrease greater than the LSC and in rest of subjects studied remained unchanged (33% patients and 19% controls) over a period of observation. In conclusion, despite comparable improvement in measured ultrasound parameter in patients and controls observed over a study duration, the difference between them remained stable.

Ten-year probabilities of clinical vertebral fractures according to phalangeal quantitative ultrasonography

The objectives of the present study were to estimate 10-year probabilities of clinical vertebral fractures in women, according to age and bone mineral assessment using phalangeal quantitative ultrasound (QUS). Risks were computed from UK derived data on the incidence of a first symptomatic vertebral fracture and mortality rates for each year of age using Poisson models. The 10-year probability of vertebral fracture was determined as the proportion of individuals fracture-free at that site from the age of 45 years. We assumed that the risk of fracture increased with decreasing QUS as assessed by an independent re-analysis of a previously published, multicenter cross-sectional study. For amplitude-dependent speed of sound (AD-SoS) information was available from 8,502 women, and vertebral fracture risk increased 1.7-fold for each SD decrease in measurement. For fast wave amplitude (FWA), available in 6,573 women, the risk gradient was 2.4/SD. In a subset of the population ( n =1,572) in whom bone mineral density was measured at the lumbar spine, the gradient of risk was 2.3/SD, with similar gradients of risk noted for AD-SoS (1.8/SD) and FWA (2.6/SD). Ten-year probabilities increased with age and decreasing Z -score. The use of absolute risk permits information from different types of bone mineral measurements to be applied for the assessment of patients, either alone or in combination with other independent risk factors.

Comparison of quantitative ultrasound of the phalanges with conventional bone densitometry in healthy postmenopausal women

The objective of this study was to evaluate the utility of the quantitative ultrasound (QUS) technique for the identification of subjects with spine fracture or low bone mineral density (BMD) previously determined by dual energy X-ray absorptiometry (DEXA). QUS of the phalanges in 1,350 postmenopausal women (60-83 years old) was compared with DEXA measurements of four skeletal sites (lumbar spine, total hip, femoral neck, and distal radius) of the same subjects. The contribution of body mass index (BMI) was also assessed. Amplitude dependent speed of sound (AD-SoS), ultrasound bone profile index (UBPI), and BMD of all anatomical regions, except for the spine, decreased significantly with increasing age quartiles. QUS parameters correlated weakly but significantly with BMD ( r =0.21-0.31, p <0.01). After adjustment for BMI, the association between QUS parameters and BMD remained unchanged. UBPI was found to be independent of BMI. All techniques and all sites were able to significantly discriminate fractured from non-fractured subjects by receiver operating characteristic (ROC) analysis (area under the curve [AUC]> or =0.60, p <0.0001). AD-SoS and UBPI showed similar fracture discrimination ability of spine, distal radius and total body BMD in terms of odds ratios, but BMD of the total hip and femoral neck showed the best performance in discriminating fractured from non-fractured subjects. In conclusion, QUS assessment of the phalanges correlates moderately with BMD of all skeletal sites and is able to effectively discriminate fractured from non-fractured subjects.