Quantitative ultrasound parameters as well as bone mineral density are better predictors of trochanteric than cervical hip fractures in elderly women. Results from the EPIDOS study

Quantitative Ultrasound and Bone Health in Elderly People, a Systematic Review

Reduced bone mineral density (BMD), osteoporosis, and their associated fractures are one of the main musculoskeletal disorders of the elderly. Quickness in diagnosis could prevent associated complications in these people. This study aimed to perform a systematic review (SR) to analyze and synthesize current research on whether a calcaneal quantitative ultrasound (QUS) can estimate BMD and predict fracture risk in elderly people compared to dual-energy x-ray absorptiometry (DXA), following the PRISMA guidelines. A search was conducted in the main open-access health science databases: PubMed and Web of Science (WOS). DXA is the gold standard for the diagnosis of osteoporosis. Despite controversial results, it can be concluded that the calcaneal QUS tool may be a promising method to evaluate BMD in elderly people, facilitating its prevention and diagnosis. However, further studies are needed to validate the use of calcaneal QUS.

Secular trends of incidence and hospitalization cost of hip fracture in Tangshan, China

We investigated the secular trends of the incidence and hospitalization cost of hip fracture in Tangshan, China. The incidence of hip fracture and the hospitalization cost were both increasing during the observation period.

INTRODUCTION

The present study aimed to determine sex-, age-, and fracture type-specific incidence and annual changes in hip fractures in Tangshan, China, between 2007 and 2018.

METHODS

We analyzed annual hip fracture incidence using urban hospital data during 2007-2018 and calculated incidence rate/100,000 person years in each age group and sex. We assessed annual changes in incidence among people aged >60 years using linear-by-linear association tests and evaluated hospitalization costs with the Kruskal-Wallis test.

RESULTS

During the study period, we observed an increasing proportion of hip fractures in people >60 years old from 14.2 to 22.79%. Crude hip fracture incidence increased markedly from 140.87 to 306.56/100,000 in women (p < 0.01) and from 124.83 to 167.19/100,000 in men (p < 0.01) in the age group >60 years. Type-specific analysis indicated significantly increased trends in incidence of cervical and trochanteric fractures among women and cervical fracture among men (p < 0.01). In people aged 36-60 years, the trend of hip fracture increased significantly in both sexes. The total and cervical-to-trochanteric ratio in men increased, with significant upward trends (p < 0.01). The proportion of cervical fracture was higher than that for trochanteric fracture in women, with stable levels from 2007 to 2018. Hospitalization costs for cervical and trochanteric fractures increased by 51.91% and 53.20%, respectively, during 2011-2018.

CONCLUSION

Tangshan will have an increasing burden on health care resources attributable to a considerable rise in hip fracture incidence and the older population. Further investigation of risk factors and subsequent implementation of effective measures to prevent hip fracture are needed.

Secular Trends of Hip Fractures in Lebanon, 2006 to 2017: Implications for Clinical Practice and Public Health Policy in the Middle East Region

Country-specific hip fracture incidence rates (IRs) and longevity allow the Fracture Risk Assessment Tool (FRAX) to be adapted to individual countries. Secular trends can affect tool calibration. Data on hip fracture IRs in the Middle East is scarce, and long-term secular trend studies are nonexistent. Using the Ministry of Public Health hip fracture registry, we calculated age- and sex-specific hip fracture IRs in Lebanon, from 2006 to 2017, among individuals aged ≥50 years. We used Kendall's tau-b (τb) test to determine the correlation between time and hip fracture IRs, and calculated both the annual % change in IRs and the % change in IR compared to the baseline period (2006 to 2008). The registry recorded 6985 hip fractures, 74% at the femoral neck, 23% intertrochanteric, and 3% subtrochanteric. Men constituted 32% of the population, and were significantly younger than women (76.5 ± 11.0 years versus 77.7 ± 10.3 years; p < 0.001). Annual overall IRs, per 100,000, ranged from 126.6 in 2014 to 213.2 in 2017 in women, and 61.4 in 2015 to 111.7 in 2017 in men. The average women to men IR ratio was 1.8 (range, 1.5 to 2.1). IRs steadily increased with age, and IR ratios increased in parallel in both sexes, with a steeper and earlier rise (by 5 years) in women. Data showed a consistent decline in hip fracture IRs starting in 2006 in women, and in 2009 in men. There was a significant negative correlation between time (2006 to 2014) and hip fracture IRs in women (τb = -0.611, p = 0.022) but not in men (τb = -0.444, p = 0.095). The steady decrease in IRs reversed after 2015 in both sexes. This long-term data on secular trends in the Middle East is novel and consistent with worldwide changes in hip fracture rates. The impact of such changes on national FRAX-derived estimates is unclear, should be assessed, and may necessitate an update in the FRAX Lebanon calculator. © 2019 American Society for Bone and Mineral Research.

Current and Emerging Diagnostic Imaging-Based Techniques for Assessment of Osteoporosis and Fracture Risk

Osteoporosis is a metabolic bone disorder characterized by low bone mass, degradation of bone microarchitecture, and susceptibility to fracture. It is a growing major health concern across the world, especially in the elderly population. Osteoporosis can cause hip or spinal fractures that may lead to high morbidity and socio-economic burden. Therefore, there is a need for early diagnosis of osteoporosis and prediction of fragility fracture risk. In this review, state of the art and recent advances in imaging techniques for diagnosis of osteoporosis and fracture risk assessment have been explored. Segmentation methods used to segment the regions of interest and texture analysis methods used for classification of healthy and osteoporotic subjects are also presented. Furthermore, challenges posed by the current diagnostic tools have been studied and feasible solutions to circumvent the limitations are discussed. Early diagnosis of osteoporosis and prediction of fracture risk require the development of highly precise and accurate low-cost diagnostic techniques that would help the elderly population in low economies.

Do we need orthogeriatrics in Poland? Changes in the age structure and location of hip fractures

Background

Patients with hip fractures present a great challenge for surgeons due to multimorbidity, polypharmacy as well as difficulty in communicating. These could be attributed to a recent trend in the aging patient population (80 years and older) as compared to the past. The aim of this study is to analyze age structure and location in male and female patients’ population with hip fracture over 50.

Materials and methods

Hospital records between 2005 and 2014 with ICD-10 codes S72,0, S72,1 and S72,2 were included in the analysis. All fractures occurred in citizen aged 50 years and over living in the district of Tarnowskie Góry and the city of Piekary Śląskie in Poland.

Results

Within the study period, 1258 hip fractures were registered. The mean age of the patients was higher every year, starting from 77.27 ± 9.52 in 2005 to 80.80 ± 9.65 years in 2014 (p < 0.01). The average age also increased in both gender groups from 73.85 ± 8.30 to 77.89 ± 9.52 years in male and from 78.14 ± 9.66 to 81.98 ± 9.49 years in female, respectively. The median age value was changed from 78.00 to 83.00 years in the total population. We noted a significant increase in female with trochanteric fracture; however, the level of neck fracture was almost the same. In men, crude rates for both trochanteric and cervical fractures slightly increased.

Conclusions

As the age of patients increases, fractures were shown to be more complicated. Given the scale of the phenomenon and its determinants, we emphatically conclude orthogeriatrics is needed in Poland.

Association between vitamin D status and serum parathyroid hormone concentration and calcaneal stiffness in Japanese adolescents: sex differences in susceptibility to vitamin D deficiency

There is currently insufficient information on serum 25-hydroxyvitamin D (25OHD) and parathyroid hormone (PTH) concentrations, and bone mineral status in healthy adolescents to allow reference values to be set. This study aimed to provide comparable data on vitamin D status in Japanese adolescents and to assess sex differences in susceptibility to vitamin D insufficiency. Serum 25OHD and PTH concentrations were measured in 1,380 healthy adolescents (aged 12-18 years). Subjects completed a questionnaire on exercise history, diet, and lifestyle factors. Calcaneal stiffness was evaluated by quantitative ultrasound. Serum 25OHD concentrations in boys and girls were 60.8 ± 18.3 and 52.8 ± 17.0 nmol/L, respectively. Approximately 30 % of boys and 47 % of girls had suboptimal 25OHD concentrations (<50 nmol/L). Serum PTH concentration was negatively correlated with serum 25OHD concentration in boys, but negatively correlated with calcium intake rather than serum 25OHD in girls. In contrast, the increment in calcaneal stiffness as a result of elevation of serum 25OHD was higher in girls than in boys. As vitamin D deficiency is common in Japanese adolescents, it was estimated that intakes of ≥12 and ≥14 μg/day vitamin D would be required to reach 25OHD concentrations of 50 nmol/L in boys and girls, respectively. Moreover, the results of the present study indicate that vitamin D deficiency has a greater association with calcaneal stiffness in girls than in boys.

Hip Fracture Types in Canadian Men and Women Change Differently with Age: A Population-Level Analysis

BACKGROUND

We have previously reported a gender difference in the occurrence of hip fracture type with age in our local population. In the current report, we have explored this phenomenon in a Canadian population using five years of data from a national administrative database. We have compared community-dwelling and institutionalized individuals to determine if frailty is important and has a differential effect on the type of hip fracture experienced.

METHODS

Hospitalization records from 2005 to 2009, in which the most responsible diagnosis, that is the diagnosis causing the admission to hospital, was a hip fracture, were obtained from the Discharge Abstract Database of the Canadian Institute for Health Information. Hip fracture type was identified using the Canadian Classification of Health Interventions and the International Classification of Diseases 10th Revision, Canada (ICD-10-CA). Hip fracture proportions were calculated for the study period and stratified by age group and sex.

RESULTS

The relative proportion of intertrochanteric fractures in women rose from 35% in the youngest group (55-59 years) to 51% in the oldest group (84+ years; P < 0.0001). In men, the proportions remain relatively stable (47% and 44%, respectively). Community and institutionalized patients showed the same pattern.

CONCLUSIONS

The change in the proportion of the two hip fracture types that occur in women but not men may point to differences in the etiology and consequently the approaches to prevention for the two fracture types. Level of frailty did not seem to be important.

The Trochanteric Localization is a Mediator of Slower Short-Term Functional Recovery in Overweight and Obese Elderly Women with Recent Hip Fracture: The BREAK Study

The hypothesis tested in this study, carried out on elderly Italian women with recent hip fracture, was to assess the extent to which the effect of a condition of being overweight/obese on short-term functional recovery as evaluated by the "time to permitted load" could be explained by a mediator variable (type of hip fracture). We studied 727 women aged 60 years or over with a recent low trauma surgically treated hip fracture and for whom an information on post-surgery complications and on the time to permitted load was available. To assess for mediation, the statistical analyses were carried out following the procedure described by Baron and Kenny. In this study, 46 % of women with hip fracture presented a time to permitted load of ≥ 10 days. The women with a post-surgery time to permitted load of ≥ 10 days showed a significantly higher proportion of trochanteric fracture localization (72.1 vs 42 %), of total overweight/obesity (46.5 vs 36.8 %) and of post-surgery complications (38.8 vs 18.8 %). The mediating effect of hip fracture localization on the association between overweight/obesity and the time of permitted load was demonstrated and confirmed in a multivariate logistic regression model. This study, carried out using a "mediator" statistical analysis, suggests that in elderly women with hip fracture being overweight/obese is associated with a slower short-term functional recovery as evaluated by the time to permitted load and that this association is mediated by the trochanteric localization of hip fracture.

Prediction of incident hip fracture with the estimated femoral strength by finite element analysis of DXA Scans in the study of osteoporotic fractures

A bone fractures only when loaded beyond its strength. The purpose of this study was to determine the association of femoral strength, as estimated by finite element (FE) analysis of dual-energy X-ray absorptiometry (DXA) scans, with incident hip fracture in comparison to hip bone mineral density (BMD), Fracture Risk Assessment Tool (FRAX), and hip structure analysis (HSA) variables. This prospective case-cohort study included a random sample of 1941 women and 668 incident hip fracture cases (295 in the random sample) during a mean ± SD follow-up of 12.8 ± 5.7 years from the Study of Osteoporotic Fractures (n = 7860 community-dwelling women ≥67 years of age). We analyzed the baseline DXA scans (Hologic 1000) of the hip using a validated plane-stress, linear-elastic finite element (FE) model of the proximal femur and estimated the femoral strength during a simulated sideways fall. Cox regression accounting for the case-cohort design assessed the association of estimated femoral strength with hip fracture. The age-body mass index (BMI)-adjusted hazard ratio (HR) per SD decrease for estimated strength (2.21; 95% CI, 1.95-2.50) was greater than that for total hip (TH) BMD (1.86; 95% CI, 1.67-2.08; p < 0.05), FN BMD (2.04; 95% CI, 1.79-2.32; p > 0.05), FRAX scores (range, 1.32-1.68; p < 0.0005), and many HSA variables (range, 1.13-2.43; p < 0.005), and the association was still significant (p < 0.05) after further adjustment for hip BMD or FRAX scores. The association of estimated strength with incident hip fracture was strong (Harrell's C index 0.770), significantly better than TH BMD (0.759; p < 0.05) and FRAX scores (0.711-0.743; p < 0.0001), but not FN BMD (0.762; p > 0.05). Similar findings were obtained for intracapsular and extracapsular fractures. In conclusion, the estimated femoral strength from FE analysis of DXA scans is an independent predictor and performs at least as well as FN BMD in predicting incident hip fracture in postmenopausal women.

Urban versus rural differences in the occurrence of hip fractures in Japan's Kyoto prefecture during 2008-2010: a comparison of femoral neck and trochanteric fractures

BACKGROUND

To investigate the differences in the characteristics of femoral neck and trochanteric fractures between urban and rural areas of Kyoto Prefecture in Japan.

METHODS

Fracture type (neck vs. trochanteric), age, sex, place where fracture occurred (indoors vs. outdoors), and cause of injury were surveyed among patients aged ≥65 years who sustained hip fractures between 2008 and 2010 and who were treated at 1 of 13 participating hospitals (5 urban, 8 rural). The ratio of sick beds to total number of beds at the participating hospitals was 19.6% (2,188/11,158) in the urban area and 34.9% (1,963/5,623) in the rural area. We also investigated the incidence of hip fracture in Tango medical district as a representative rural area.

RESULTS

There were 1,346 neck (mean age, 82.4 years) and 1,606 trochanteric fractures (mean age, 85.0 years). The ratio of neck to trochanteric fractures was higher in the urban area than in the rural area in all age groups (65-74, 75-84, and ≥ 85 years). There were no apparent differences in place or cause of injury. The incidence of hip fracture in the women of Tango medical district was lower than the national average.

CONCLUSIONS

There was a difference in the ratio of neck to trochanteric fractures between urban and rural areas. This difference is estimated to be caused by the high and low incidence of neck fracture in urban and rural areas, respectively.

Surgical treatment of trochanteric and cervical hip fractures in the United States: 2000-2009

The objective of this study was to evaluate the most common treatments performed for hip fractures over the last decade in the United States. The leading treatment for trochanteric fractures was internal fixation, accounting for 96%-98% of surgical treatments each year. For cervical fractures, hemiarthroplasty (HA), total hip arthroplasty (THA), and internal fixation were performed nearly 61%, 5%, and 33% of the time, respectively, each year without any sign of change during the period assessed. The surgical choice for cervical fractures varied greatly by patient age. In 2009, two-thirds of patients younger than 60 years underwent internal fixation while two-thirds of patients 60 years or older underwent HA. Regardless of patient age, HA was performed more often than THA for cervical hip fractures.

The assessment of vertebral fractures in elderly women with recent hip fractures: the BREAK Study

This study aimed to evaluate the prevalence of vertebral fractures in elderly women with a recent hip fracture. The burden of vertebral fractures expressed by the Spinal Deformity Index (SDI) is more strictly associated with the trochanteric than the cervical localization of hip fracture and may influence short-term functional outcomes.

INTRODUCTION

This study aimed to determine the prevalence and severity of vertebral fractures in elderly women with recent hip fracture and to assess whether the burden of vertebral fractures may be differently associated with trochanteric hip fractures with respect to cervical hip fractures.

METHODS

We studied 689 Italian women aged 60 years or over with a recent low trauma hip fracture and for whom an adequate X-ray evaluation of spine was available. All radiographs were examined centrally for the presence of any vertebral deformities and radiological morphometry was performed. The SDI, which integrates both the number and the severity of fractures, was also calculated.

RESULTS

Prevalent vertebral fractures were present in 55.7% of subjects and 95 women (13.7%) had at least one severe fracture. The women with trochanteric hip fracture showed higher SDI and higher prevalence of diabetes with respect to those with cervical hip fracture, p=0.017 and p=0.001, respectively. SDI, surgical menopause, family history of fragility fracture, and type2 diabetes mellitus were independently associated with the risk of trochanteric hip fracture. Moreover, a higher SDI was associated with a higher percentage of post-surgery complications (p=0.05) and slower recovery (p<0.05).

CONCLUSIONS

Our study suggests that the burden of prevalent vertebral fractures is more strictly associated with the trochanteric than the cervical localisation of hip fracture and that elevated values of SDI negatively influence short term functional outcomes in women with hip fracture.

Hip fractures in the United States: 2008 nationwide emergency department sample

OBJECTIVE

To evaluate the recent epidemiology of hip fractures in the US.

METHODS

We identified hip fracture cases from the 2008 Nationwide Emergency Department Sample, which contains more than 28 million emergency department (ED) records.

RESULTS

In 2008, approximately 341,000 (95% confidence interval 323,000-358,000) patients visited EDs with hip fractures. Of those, 90% were age >60 years. Between ages 60-85 years, the risk of fracture doubled for every 5- to 6-year increase in age. However, the hip fracture risk increased slowly after age 85 years. The overall trochanteric-to-cervical fracture ratio was nearly 2:1. The risk of trochanteric fracture increased faster with age compared with the risk of cervical fracture. At age 85 years, the rates of trochanteric and cervical fractures (per 100,000) were 1,300 and 700, respectively, among women and 800 and 500, respectively, among men.

CONCLUSION

The slowed growth of hip fracture risk after age 85 years suggests that the eldest old group may have a distinct hip fracture risk. Our study showed that trochanteric fractures were twice as common as cervical fractures. Because trochanteric fractures are more closely related to severe and generalized bone loss than cervical fractures, we hypothesize that the high incidence rate of trochanteric fractures in the US suggests that osteoporosis is a health problem that is linked to hip fracture. In addition to improved safety measures to reduce falls, rigorous preventive treatments of osteoporosis may be needed.

Genetic polymorphisms of the Wnt receptor LRP5 are differentially associated with trochanteric and cervical hip fractures

Epidemiological studies suggest that cervical and trochanteric hip fractures have different pathogenesis. We tested the hypothesis that genetic factors have different influences on both types of fractures. Ten polymorphisms of genes known to play an important role in skeletal homeostasis [estrogen receptor alpha (ESR1), aromatase (CYP19A1), type I collagen (COL1A1), and lipoprotein receptor-related protein 5 (LRP5)] were analyzed in 471 Spanish patients with fragility hip fractures. Two polymorphisms of the LRP5 gene (rs7116604 and rs3781600) were associated with the type of fracture (P = 0.0085 and 0.0047, respectively). The presence of rare alleles at each locus was associated with trochanteric fractures over cervical fractures (OR = 1.7 in individuals with at least one rare allele at rs7116604 or rs3781600 loci in comparison with the common homozygotes). Considering individuals bearing the four common alleles as reference, the OR for trochanteric fractures was 1.6 in those with one or two rare alleles and 7.5 in those with three or four rare alleles (P for trend = 0.0074), which is consistent with an allele-dosage effect. There were no significant differences in the frequency distributions of the ESR1, CYP19A1, and COL1A1 genotypes between trochanteric and cervical fractures in either the original group or an extended group of 818 patients. These results suggest that LRP5 alleles influence the type of hip fractures. They support the view that different genetic factors are involved in cervical and trochanteric fractures, which should be taken into consideration in future genetic association studies.

Assessment of bone status in inhaled corticosteroid user asthmatic patients with an ultrasound measurement method

BACKGROUND

The effect of inhaled corticosteroid (ICS) on the bone status of asthmatic patients is still uncertain, because it can differ by race and because there have been few cases in Japan. In this study, the bone status of ICS users with asthma was evaluated in an actual clinical setting in Japan.

METHODS

In 7 participating hospitals, ICS users with asthma and control subjects were age- and gender-matched and recruited into this study. To assess bone status, ultrasound measurements of each individual's calcaneus were made using an AOS-100. The ratio of the osteo sono-assessment index (OSI) to the average OSI corrected for age and gender was denoted as %OSI and used for quantitative assessment. The second %OSI measurement was performed 6 months after the first %OSI one. During the study period, individual treatment remained unchanged.

RESULTS

There were no significant differences in the 1st and 2nd %OSI between the ICS users and control subjects. However, the 2nd %OSI significantly decreased compared with 1st %OSI in female ICS users, although there were no significant changes in the male and female control subjects and male ICS users.

CONCLUSIONS

The 6 month management of asthma in the actual clinical setting, including regular ICS use, might have a harmful influence on the bone status of female asthmatic patients. It may be necessary to manage and treat female patients for potent corticosteroid-induced osteoporosis, although further analyses of bone status in asthma patient ICS users will be required.

Combination of radiograph-based trabecular and geometrical parameters can discriminate cervical hip fractures from controls in individuals with BMD in non-osteoporotic range

Majority of hip fractures occur in individuals with bone mineral density (BMD) in non-osteoporotic range. This suggests that factors other than BMD are associated with increased fracture risk in these individuals. The aim of this study was to investigate the combined ability of radiograph-based trabecular and geometrical parameters to discriminate cervical hip fractures from controls in individuals with non-osteoporotic BMD. A total of 39 postmenopausal females with non-pathologic cervical hip fracture were recruited to the study. Nineteen of the fracture patients (48.7%) had non-osteoporotic BMD and they constituted the fracture group. The control group consisted of 35 BMD-matched non-osteoporotic females. Several geometrical and trabecular parameters were extracted from plain pelvic radiographs, and their combined ability to discriminate fracture patients from controls was studied using a receiver operating characteristics (ROC) analysis. Significant differences in several radiograph-based geometrical and trabecular parameters were found between the fracture patients and controls, whereas no statistically significant difference in BMD was observed (p=0.92) between the groups. Area under the ROC curve was 0.993 (95% CI 0.977-1.008) for the combined multiple regression model, which included both trabecular and geometrical parameters as explanatory factors. Here, the sensitivity of 100% was achieved with the specificity of 94%. In a cross-validation of the model, 94.4% of the fracture patients, and 94.1% of the controls were classified correctly. The combination of radiograph-based trabecular and geometrical parameters was able to discriminate the cervical hip fracture cases from controls with similar BMD, showing that the method can provide additional information on bone structure and fracture risk beyond BMD.

Anatomical variance in acetabular anteversion does not predict hip fracture patterns in the elderly: a retrospective study in 135 patients

It has been suggested that variances in the anatomy of the acetabulum determine the type of hip fracture in elderly patients. Based on this concept, an overly anteverted acetabulum would lead to impingement of the femoral neck against the posterior rim of the acetabulum, causing a femoral neck fracture, whereas with a retroverted acetabulum, external rotation of the hip would be limited by the capsular tissues attached to the trochanteric region, causing a trochanteric fracture. To test the hypothesis that acetabular version predicts hip fracture type in elderly patients, we measured acetabular version using computed tomography scans for 135 patients with hip fracture. Logistic regression analysis was used to check for an association between version angle and fracture type. No significant relationship between acetabular version and fracture type was found. Therefore, we conclude that acetabular version angle does not predict hip fracture type in the elderly, and our data do not support the impingement concept as the mechanism of hip fractures.

Risk factors for cervical and trochanteric hip fractures in elderly women: a population-based 10-year follow-up study

We evaluated the contribution of lifestyle-related factors, calcaneal ultrasound, and radial bone mineral density (BMD) to cervical and trochanteric hip fractures in elderly women in a 10-year population-based cohort study. The study population consisted of 1,681 women (age range 70-73 years). Seventy-two percent (n = 1,222) of them participated in the baseline measurements. Calcaneal ultrasound was assessed with a quantitative ultrasound device. BMD measurements were performed at the distal and ultradistal radius by dual-energy X-ray absorptiometry. Forward stepwise logistic regression analysis was used to find the most predictive variables for hip fracture risk. During the follow-up, 53 of the women had hip fractures, including 32 cervical and 21 trochanteric ones. The fractured women were taller and thinner and had lower calcaneal ultrasound values than those without fractures. High body mass index (BMI) was a protective factor against any hip fractures, while low functional mobility was a risk factor of hip fractures. Specifically, high BMI protected against cervical hip fractures, while low physical activity was a significant predictor of these fractures. Similarly, high BMI protected against trochanteric fractures, whereas low functional mobility and high coffee consumption were significant predictors of trochanteric fractures. Cervical and trochanteric hip fractures seem to have different risk factors. Therefore, fracture type should be taken into account in clinical fracture risk assessment and preventative efforts, including patient counseling. However, the study is not conclusive due to the limited number of observed fractures during follow-up, and the results have to be confirmed in future studies.

Hip fracture types in men and women change differently with age

Background

Hip fractures are expensive and a frequent cause of morbidity and mortality in the elderly. In most studies hip fractures have been viewed as a unitary fracture but recently the two main types of fracture (intertrochanteric and subcapital) have been viewed as two fractures with a different etiology and requiring a different approach to prevention. The relative proportion of intertrochanteric fractures increases with age in women. In previous studies no particular pattern in men has been noted. In this study, we explored changes in the relative proportion of the two fracture types with age in the two genders.

Methods

Patients of 50 years and older, with a diagnosis of hip fracture, discharged from two local acute care hospitals over a 5 year period (n = 2150) were analyzed as a function of age and gender to explore the relative proportions of intertrochanteric and subcapital fractures, and the change in relative proportion in the two genders with age.

Results

Overall, for the genders combined, the proportion of intertrochanteric fractures increases with age (p = .007). In women this increase is significant (p < .001), but in men the opposite pattern is observed, with the proportion of intertrochanteric fractures falling significantly with age (p = .025).

Conclusions

The pattern of hip fractures is different in men and women with aging. It is likely that the pattern difference reflects differences in type and rate of bone loss in the genders, but it is conjectured that the changing rate and pattern of falling with increasing age may also be important. The two main hip fracture types should be considered distinct and different and be studied separately in studies of cause and prevention.

In vivo performance evaluation of bi-directional ultrasonic axial transmission for cortical bone assessment

Our objective was to assess a new quantitative ultrasound device suitable for the measurement of speed of sound in radius. The so-called "bidirectional" technique allows an accurate estimation of velocity based on a compensation for soft tissue effects implemented directly inside the probe. Velocity measurements at 1 MHz of the first arriving signal were performed at the one third distal radius in 358 enrolled women. The average velocity by age decade increases to a peak velocity of 4043 m/s in the class 30-39 y (n = 19) and decreases thereafter. Fracture discrimination was investigated on the subset of the population for which dual-energy x-ray absorptiometry measurement was available, in addition to first arriving signal velocity measurements. The study group consisted of 122 postmenopausal women without history of fracture (group NF) and 44 postmenopausal patients (group F) with osteoporotic fractures (hip, spine, Colles fracture). When adjusted for age and bone mass index, the odds ratio (OR) for fracture prediction by ultrasound velocity, was 1.81 (1.21; 2.70) and OR associated to neck femur BMD was 2.07 (1.31-3.29). For the full model including age and body mass index as cofactors, the area under the receiver operating characteristic curve was 0.77, either for ultrasound velocity or neck femur bone mineral density. Despite the small population and the variety of fractures in the fracture group, our data indicate that the velocity of the first arriving signal measured by bidirectional technique discriminates patients with osteoporotic fracture from controls.

Bone sonometry: reducing phase aberration to improve estimates of broadband ultrasonic attenuation

Previous studies suggest that phase cancellation at the receiving transducer can result in the overestimation of the frequency dependent ultrasonic attenuation of bone, a quantity that has been shown to correlate with bone mineral density and ultimately with osteoporotic fracture risk. Evidence supporting this interpretation is provided by phase insensitive processing of the data, which appear to reduce the apparent overestimates of attenuation. The present study was designed to clarify the components underlying phase aberration artifacts in such through-transmission measurements by conducting systematic studies of the simplest possible test objects capable of introducing phase aberration. Experimental results are presented for a Lexan phantom over the frequency range 300-700 kHz and a Plexiglas phantom over the 3-7 MHz range. Both phantoms were flat and parallel plates featuring a step discontinuity milled into one of their initially flat sides. The through-transmitted signals were received by a 0.6 mm diameter membrane hydrophone that was raster scanned over a grid coaxial with the transmitting transducer. Signals received by the pseudoarray were processed offline to emulate phase sensitive and phase insensitive receivers with different aperture diameters. The data processed phase sensitively were focused to demonstrate the results of planar, geometrical, and correlation-based aberration correction methods. Results are presented illustrating the relative roles of interference in the ultrasonic field and phase cancellation at the receiving transducer in producing phase aberration artifacts. It was found that artifacts due to phase cancellation or interference can only be minimized with phase insensitive summation techniques by choosing an appropriately large receiving aperture. Data also suggest the potentially confounding role of time-and frequency-domain artifacts on ultrasonic measurements and illustrate the advantages of two-dimensional receiving arrays in determining the slope of attenuation (nBUA) for the clinical assessment of osteoporosis.

Ultrasonic attenuation in parallel-nylon-wire cancellous-bone-mimicking phantoms

Attenuation coefficients between 1.5 and 3.5 MHz were measured on four parallel-nylon-wire arrays (simulating cancellous bone) with four different wire diameters (150, 200, 250, and 300 microm). Interwire spacing was 800 microm for all four parallel-nylon-wire arrays. The measured frequency dependencies of attenuation were consistent with theoretical predications based on Faran's theory, which considers the component of attenuation due to scattering of longitudinal waves.

Mechanisms for attenuation in cancellous-bone-mimicking phantoms

Broadband ultrasound attenuation (BUA) in cancellous bone is useful for prediction of osteoporotic fracture risk, but its causes are not well understood. To investigate attenuation mechanisms, 9 cancellous-bone-mimicking phantoms containing nylon filaments (simulating bone trabeculae) embedded within soft-tissue-mimicking fluid (simulating marrow) were interrogated. The measurements of frequency-dependent attenuation coefficient had 3 separable components: 1) a linear (with frequency) component attributable to absorption in the soft-tissue-mimicking fluid, 2) a quasilinear (with frequency) component, which may include absorption in and longitudinal-shear mode conversion by the nylon filaments, and 3) a nonlinear (with frequency) component, which may be attributable to longitudinal-longitudinal scattering by the nylon filaments. The slope of total linear (with frequency) attenuation coefficient (sum of components #1 and #2) versus frequency was found to increase linearly with volume fraction, consistent with reported measurements on cancellous bone. Backscatter coefficient measurements in the 9 phantoms supported the claim that the nonlinear (with frequency) component of attenuation coefficient (component #3) was closely associated with longitudinal-longitudinal scattering. This work represents the first experimental separation of these 3 components of attenuation in cancellous bone-mimicking phantoms.

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.

Ultrasonic scattering from cancellous bone: a review

This paper reviews theory, measurements, and computer simulations of scattering from cancellous bone reported by many laboratories. Three theoretical models (binary mixture, Faran cylinder, and weak scattering) for scattering from cancellous bone have demonstrated some consistency with measurements of backscatter. Backscatter is moderately correlated with bone mineral density in human calcaneus in vitro (r(2) = 0.66 - 0.68). Backscatter varies approximately as frequency cubed and trabecular thickness cubed in human calcaneus and femur in vitro. Backscatter from human calcaneus and bovine tibia exhibits substantial anisotropy. So far, backscatter has demonstrated only modest clinical utility. Computer simulation models have helped to elucidate mechanisms underlying scattering from cancellous bones.

A method for improved standardization of in vivo calcaneal time-domain speed-of-sound measurements

Although calcaneal speed of sound (SOS) is an effective predictor of osteoporotic fracture risk, clinical SOS measurements exhibit a high degree of inter-system variability. Calcaneal SOS is usually computed from time-of-flight measurements of broadband ultrasound pulses that propagate through the foot. In order to minimize the effects of multi-path interference, many investigators measure time-of-flight from markers near the leading edge of the pulse. The calcaneus is a highly attenuating, highly inhomogeneous bone that distorts propagating ultrasound pulses via frequency-dependent attenuation, reverberation, dispersion, multiple scattering, and refraction. This pulse distortion can produce errors in leading-edge transit-time marker-based SOS measurements. In this paper, an equation to predict dependence of time-domain SOS measurements on system parameters (center frequency and bandwidth), transit-time marker location, and bone properties (attenuation coefficient and thickness) is validated with through-transmission measurements in a bone-mimicking phantom and in 73 women in vivo, using a clinical bone sonometer. In order to test the utility of the formula for suppressing system dependence of SOS measurements, a wideband laboratory data acquisition system was used to make a second set of through-transmission measurements on the phantom. The compensation formula reduced system-dependent leading-edge transit-time marker-based SOS measurements in the phantom from 41 m/s to 5 m/s and reduced average transit-time marker-related SOS variability in 73 women from 40 m/s to 10 m/s. The compensation formula can be used to improve standardization in bone sonometry.

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.

Defining risk thresholds for a 10-year probability of hip fracture model that combines clinical risk factors and quantitative ultrasound: results using the EPISEM cohort

Using a large prospective cohort of over 12,000 women, we determined 2 thresholds (high risk and low risk of hip fracture) to use in a 10-yr hip fracture probability model that we had previously described, a model combining the heel stiffness index measured by quantitative ultrasound (QUS) and a set of easily determined clinical risk factors (CRFs). The model identified a higher percentage of women with fractures as high risk than a previously reported risk score that combined QUS and CRF. In addition, it categorized women in a way that was quite consistent with the categorization that occurred using dual X-ray absorptiometry (DXA) and the World Health Organization (WHO) classification system; the 2 methods identified similar percentages of women with and without fractures in each of their 3 categories, but the 2 identified only in part the same women. Nevertheless, combining our composite probability model with DXA in a case findings strategy will likely further improve the detection of women at high risk of fragility hip fracture. We conclude that the currently proposed model may be of some use as an alternative to the WHO classification criteria for osteoporosis, at least when access to DXA is limited.

The effect of phase cancellation on estimates of broadband ultrasound attenuation and backscatter coefficient in human calcaneus in vitro

Broadband ultrasound attenuation (BUA) is a clinically proven indicator of osteoporotic fracture risk. BUA measurements are typically performed in throughtransmission with single-element phase sensitive (PS) receivers and therefore can be compromised by phase cancellation artifact. Phase-insensitive (PI) receivers suppress phase cancellation artifact. To study the effect of phase cancellation on BUA measurements, through-transmission measurements were performed on 16 human calcaneus samples in vitro using a two-dimensional receiver array that enabled PS and PI BUA estimation. The means plus or minus standard deviations for BUA measurements were 22.1 +/- 15.8 dB/MHz (PS) and 17.6 +/- 7.2 dB/MHz (PI), suggesting that, on the average, approximately 20% of PS BUA values in vitro can be attributed to phase cancellation artifact. Therefore, although cortical plates are often regarded as the primary source of phase cancellation artifact, the heterogeneity of cancellous bone in the calcaneal interior may also be a significant source. Backscatter coefficient estimates in human calcaneus that are based on PS attenuation compensation overestimate 1) average magnitude of backscatter coefficient at 500 kHz by a factor of about 1.6 +/- 0.3 and 2) average exponent (n) of frequency dependence by about 0.34 +/- 0.12 (where backscatter coefficient is fit to a power law form proportional to frequency to the nth power).

Clinical risk factors for fracture in postmenopausal osteoporotic women: a review of the recent literature

OBJECTIVE

To review recent literature regarding relationships among age, weight or body mass index (BMI), bone mineral density (BMD), maternal history of fracture, or personal prior history of fracture and fragility fractures in women with postmenopausal osteoporosis (PMO).

DATA SOURCES

A MEDLINE database search (1995-June 30, 2007) was conducted to identify literature related to risk factors of interest for PMO-related fractures.

STUDY SELECTION AND DATA EXTRACTION

Cohort studies, case-control studies, and meta-analyses that reported fracture outcomes were included if they provided an estimate of relative risk for at least 1 of the 5 selected clinical risk factors (CRFs) and studied women with PMO or stratified risk estimates by age and sex. Of 313 identified studies that evaluated fractures as an endpoint, 245 did not report risk estimates for a CRF of interest and/or did not report data for a PMO population.

DATA SYNTHESIS

In the 68 included articles, the risks associated with the evaluated CRFs were high and significant. Prior fracture was a strong predictor of fracture and increased risk up to 18 times. Each standard deviation below the referent mean for BMD was associated with an increased fracture risk of up to 4.0 times; maternal fracture history increased risk 1.3-2.9 times. Age (per 5 year increment) increased risk by 1.2-5.0 times; low weight or BMI inconsistently showed a 0.5-3.0 times greater risk.

CONCLUSIONS

Low BMD is widely used as a diagnostic indicator for osteoporosis; however, other CRFs play an important role in determining fracture risk among women with PMO.

Combining clinical factors and quantitative ultrasound improves the detection of women both at low and high risk for hip fracture

We hypothesized that combining clinical risk factors (CRF) with the heel stiffness index (SI) measured via quantitative ultrasound (QUS) would improve the detection of women both at low and high risk for hip fracture. Categorizing women by risk score improved the specificity of detection to 42.4%, versus 33.8% using CRF alone and 38.4% using the SI alone. This combined CRF-SI score could be used wherever and whenever DXA is not readily accessible.

INTRODUCTION AND HYPOTHESIS

Several strategies have been proposed to identify women at high risk for osteoporosis-related fractures; we wanted to investigate whether combining clinical risk factors (CRF) and heel QUS parameters could provide a more accurate tool to identify women at both low and high risk for hip fracture than either CRF or QUS alone.

METHODS

We pooled two Caucasian cohorts, EPIDOS and SEMOF, into a large database named "EPISEM", in which 12,064 women, 70 to 100 years old, were analyzed. Amongst all the CRF available in EPISEM, we used only the ones which were statistically significant in a Cox multivariate model. Then, we constructed a risk score, by combining the QUS-derived heel stiffness index (SI) and the following seven CRF: patient age, body mass index (BMI), fracture history, fall history, diabetes history, chair-test results, and past estrogen treatment.

RESULTS

Using the composite SI-CRF score, 42% of the women who did not report a hip fracture were found to be at low risk at baseline, and 57% of those who subsequently sustained a fracture were at high risk. Using the SI alone, corresponding percentages were 38% and 52%; using CRF alone, 34% and 53%. The number of subjects in the intermediate group was reduced from 5,400 (including 112 hip fractures) and 5,032 (including 111 hip fractures) to 4,549 (including 100 including fractures) for the CRF and QUS alone versus the combination score.

CONCLUSIONS

Combining clinical risk factors to heel bone ultrasound appears to correctly identify more women at low risk for hip fracture than either the stiffness index or the CRF alone; it improves the detection of women both at low and high risk.

Quantitative ultrasound calcaneous measurements: normative data for the Italian population. the ESOPO study

Quantitative ultrasound (QUS) is a reliable technique to evaluate skeletal status, to identify osteoporotic subjects, and to estimate the risk of fractures. The purpose of this study was to generate QUS normative data for Italian females and males aged 60-79 yr participating in the Epidemiologic Study on the Prevalence of Osteoporosis (ESOPO) study, using the Achilles Plus apparatus. ESOPO is a cross-sectional study conducted in 2000, aiming at assessing risk of osteoporosis in a random sample of 11,011 women and 4981 men, representative of the Italian population. All participants were administered a questionnaire on the most relevant risk factors for osteoporosis and fractures; 3 QUS parameters were also measured: broadband ultrasound attenuation (BUA); speed of sound (SOS); and Stiffness Index (SI). We studied the age-dependent changes in QUS values, and their correlation with body size. For both men and women, weight was the variable with the highest correlation with BUA and SI; for SOS, age among women and body mass index (BMI) among men presented the highest correlation coefficients. Average decreases of 3.0% in BUA, 0.8% in SOS, and 9.1% in SI from 60 to 79 yr were detected for females, whereas no significant changes with age in males were observed. Our data show lower QUS values for women, and a decline at a greater rate than in men.

The effect of phase cancellation on estimates of calcaneal broadband ultrasound attenuation in vivo

Broadband ultrasonic attenuation (BUA) is a clinically-accepted measurement for prediction of osteoporotic fracture risk. Typical clinical BUA measurements are performed with phase-sensitive receivers and, therefore, can be affected by phase cancellation. In order to separate the effects of conventional attenuation (absorption plus scattering) from phase cancellation, BUA was measured on phantoms with acrylic wedge phase aberrators and on 73 women using both phase sensitive (PS) and phase insensitive (PI) reception. A clinical bone sonometer with a two-dimensional (2-D) receiver array was used. PI BUA measurements on phantoms with acrylic wedge phase aberrators were found to be far more resistant to phase cancellation than PS BUA measurements. In data from 73 women, means and standard deviations for BUA measurements were 81.4 +/- 21.4 dB/MHz (PS) and 67.2 +/- 9.7 dB/MHz (PI). The magnitude of the discrepancy between PS BUA and PI BUA tended to increase with bone mineral density (BMD).

Hip fracture discrimination by the Achilles Insight QUS imaging device

The importance of osteoporosis as a major health problem is well recognized. Its major clinical manifestation is low energy fractures. Considerable effort has been directed towards search of noninvasive methods for assessing osteoporotic fracture risk. The aim of this study was to evaluate the ability of quantitative ultrasound (QUS) variables measured by a new heel QUS imaging device to discriminate between postmenopausal women with and without hip fracture. The subjects included 30 postmenopausal female patients with hip fracture and 30 age-matched healthy women. Measurements were acquired using the Achilles Insight QUS imaging device. Bone mineral density (BMD) measurements were carried out using the Lunar Prodigy DXA scanner. Achilles Insight provides images of the heel bone and measures broadband ultrasound attenuation (BUA) and speed of sound (SOS) values in a circular region of interest. A third QUS variable, the stiffness index (SI) was also determined. The short-term precision for healthy subjects was 2.05%, 0.17% and 1.91% for BUA, SOS and SI, respectively. Corresponding values for patients with fractures were 1.80%, 0.16% and 2.04%. All QUS variables measured using the Achilles Insight were significant discriminators of hip fractures (area under ROC curve=0.77, 0.74 and 0.77 for BUA, SOS and SI, respectively). BMD measurements of the hip had the greatest discriminatory ability (area under ROC curve=0.88). Statistically significant differences were found between the area under the ROC curve of BMD and the corresponding curves of the QUS variables (P<0.05 for each of the three comparisons). QUS variables measured by Achilles Insight can be expected to be useful as indicators of the risk of hip fracture in postmenopausal women.

Prediction and discrimination of osteoporotic hip fracture in postmenopausal women

Osteoporotic hip fractures increase dramatically with age and are responsible for considerable morbidity and mortality. Several treatments to prevent the occurrence of hip fracture have been validated in large randomized trials and the current challenge is to improve the identification of individuals at high risk of fracture who would benefit from therapeutic or preventive intervention. We have performed an exhaustive literature review on hip fracture predictors, focusing primarily on clinical risk factors, dual X-ray absorptiometry (DXA), quantitative ultrasound, and bone markers. This review is based on original articles and meta-analyses. We have selected studies that aim both to predict the risk of hip fracture and to discriminate individuals with or without fracture. We have included only postmenopausal women in our review. For studies involving both men and women, only results concerning women have been considered. Regarding clinical factors, only prospective studies have been taken into account. Predictive factors have been used as stand-alone tools to predict hip fracture or sequentially through successive selection processes or by combination into risk scores. There is still much debate as to whether or not the combination of these various parameters, as risk scores or as sequential or concurrent combinations, could help to better predict hip fracture. There are conflicting results on whether or not such combinations provide improvement over each method alone. Sequential combination of bone mineral density and ultrasound parameters might be cost-effective compared with DXA alone, because of fewer bone mineral density measurements. However, use of multiple techniques may increase costs. One problem that precludes comparison of most published studies is that they use either relative risk, or absolute risk, or sensitivity and specificity. The absolute risk of individuals given their risk factors and bone assessment results would be a more appropriate model for decision-making than relative risk. Currently, a group appointed by the World Health Organization and lead by Professor John Kanis is working on such a model. It will therefore be possible to further assess the best choice of threshold to optimize the number of women needed to screen for each country and each treatment.

Prediction of hip fracture risk by quantitative ultrasound in more than 7000 Swiss women > or =70 years of age: comparison of three technologically different bone ultrasound devices in the SEMOF study

To compare the prediction of hip fracture risk of several bone ultrasounds (QUS), 7062 Swiss women > or =70 years of age were measured with three QUSs (two of the heel, one of the phalanges). Heel QUSs were both predictive of hip fracture risk, whereas the phalanges QUS was not.

INTRODUCTION

As the number of hip fracture is expected to increase during these next decades, it is important to develop strategies to detect subjects at risk. Quantitative bone ultrasound (QUS), an ionizing radiation-free method, which is transportable, could be interesting for this purpose.

MATERIALS AND METHODS

The Swiss Evaluation of the Methods of Measurement of Osteoporotic Fracture Risk (SEMOF) study is a multicenter cohort study, which compared three QUSs for the assessment of hip fracture risk in a sample of 7609 elderly ambulatory women > or =70 years of age. Two QUSs measured the heel (Achilles+; GE-Lunar and Sahara; Hologic), and one measured the heel (DBM Sonic 1200; IGEA). The Cox proportional hazards regression was used to estimate the hazard of the first hip fracture, adjusted for age, BMI, and center, and the area under the ROC curves were calculated to compare the devices and their parameters.

RESULTS

From the 7609 women who were included in the study, 7062 women 75.2 +/- 3.1 (SD) years of age were prospectively followed for 2.9 +/- 0.8 years. Eighty women reported a hip fracture. A decrease by 1 SD of the QUS variables corresponded to an increase of the hip fracture risk from 2.3 (95% CI, 1.7, 3.1) to 2.6 (95% CI, 1.9, 3.4) for the three variables of Achilles+ and from 2.2 (95% CI, 1.7, 3.0) to 2.4 (95% CI, 1.8, 3.2) for the three variables of Sahara. Risk gradients did not differ significantly among the variables of the two heel QUS devices. On the other hand, the phalanges QUS (DBM Sonic 1200) was not predictive of hip fracture risk, with an adjusted hazard risk of 1.2 (95% CI, 0.9, 1.5), even after reanalysis of the digitalized data and using different cut-off levels (1700 or 1570 m/s).

CONCLUSIONS

In this elderly women population, heel QUS devices were both predictive of hip fracture risk, whereas the phalanges QUS device was not.