老年女性髋部骨折与DXA骨强度参数的相关性研究

目的探讨髋部骨强度参数对老年女性髋部骨折的影响。方法对2014年10月-2017年2月至南京市中医院骨伤科就诊体检、年龄大于60岁的受试者进行双能X线测定,并收集受试者髋部骨折病史等临床资料进行回顾性分析。共纳入93名受试者,按骨折史分为髋部骨折组33人,胸腰椎骨折组32人,正常组28人,对骨密度、髋部几何参数及髋部力学参数进行统计学分析。结果股骨颈BMD(g/cm~2)、全髋BMD(g/cm2)、股骨颈皮质比率(%)、股骨颈最小宽度(mm)、d3(mm)、y(mm)等参数与老年女性髋部骨折具有显著相关性。结论本项研究基于双能X线测定法,发现部分髋部几何力学参数与老年女性髋部骨折相关,具有重要的临床指导意义,同时改变了单一的"低骨量—高骨折风险"预测模式,形成"骨密度+髋部几何力学分析"多元化模式,可有效提高老年女性髋部骨折风险的预测能力。     

Definition of a population-specific DXA reference standard in Italian women: the Densitometric Italian Normative Study (DINS)

Osteoporosis is currently defined on the basis of the T-score by dual-energy X-ray absorptiometry (DXA). Despite its limitations, this definition is applied worldwide. However, the normal values provided by manufacturers may not be fully representative of specific local populations. So far, there are no normative data in the Italian population using Hologic densitometers. The Densitometric Italian Normative Study (DINS) is an ongoing multi-center study that aims to establish reference values for bone densitometry with dual-energy X-ray absorptiometry (DXA) in the male and female Italian population. In this paper we report the results of the lumbar vertebrae (L2–L4) and proximal femur in 1,622 women aged 20–79 years. Bone mineral density (BMD) was determined using dual-energy X-ray absorptiometry (DXA) on Hologic bone densitometers (Hologic, Waltham, Mass.). Most of the subjects were examined with a QDR 4500. The BMD of the lumbar vertebrae was virtually constant between 20 and 49 years (test for trend: P=0.66); the BMD values between 20–45 in premenopausal women (mean 1.036; SD 0.109 g/cm²) were thus defined as the peak bone mass values, significantly lower compared to the Hologic reference curve (mean 1.079, SD 0.11 g/cm²). The mean BMD values of the femoral neck were virtually identical to those of the NHANES study in the first 3 decades; after the age of 50 the BMD values were slightly greater than those of the NHANES subject. The subject classification according to the WHO criteria was similar using the DINS and NHANES reference values for the femur; for the spine, the Hologic reference values classified a larger proportion of women as osteoporotic (21 vs. 16%) or osteopenic (42 vs. 38%) compared to DINS.     

Bilateral comparison of femoral bone density and hip axis length from single and fan beam DXA scans

Dominant/nondominant differences in bone mineral density (BMD) have been observed in the upper extremities. However for the proximal femur, the distinction between dominant and nondominant hips is not clear. The purpose of this study is to evaluate left/right variations in femoral BMD and hip axis length (HAL) in both single beam and fan beam dual x-ray absorptiometry (DXA) scans. A total of 36 women aged 41–76 years (average age 60±10 years) received single beam and fan beam DXA scans of both proximal femora with a Hologic QDR-2000 scanner. Femoral BMD and hip axis length were determined for each scan. Left/right and single beam/fan beam correlations were determined and differences were evaluated using a two-way analysis of variance. Femoral BMD at corresponding measurement regions in opposing femora were highly correlated (r=0.81–0.96). No significant left/right differences were detected. At the femoral neck, the mean BMD difference (± standard deviation) was 1.5%±4.7% in a single beam mode and-0.6%±6.3% in fan beam mode. Though mean values of femoral BMD were equivalent, the observed individual left/right differences were occasionally large (as high as 26% in the femoral neck). The hip axis length of the left and right hips were highly correlated and statistically equivalent. However, hip axis length using fan beam was significantly larger (7.5%) than the single beam measurement with a larger observed variation. We conclude that measurement of a single proximal femur will usually be sufficient for clinical evaluation of BMD and/or hip axis length. However, bilateral BMD measurements are indicated in subjects where unilateral degeneration or disease are suspected. If possible, hip axis length should be measured in single beam mode to avoid magnification errors.     

Fundamentals and pitfalls of bone densitometry using dual-energy X-ray absorptiometry (DXA)

Measurement of bone mineral density (BMD) with central dual-energy X-ray absorptiometry (DXA) is the current gold standard for diagnosing osteoporosis and for monitoring patients. Errors in demographic information, improper patient positioning, incorrect scan analysis, and mistakes in interpretation can all lead to a wrong clinical decision or action. This paper reviews the fundamentals of positioning, scan analysis, and interpretation for central DXA and highlights some of the common pitfalls that may lead to erroneous results.     

定量与半定量方法评估DXA影像发现椎体骨折的比较

目的比较形态学定量评估方法和Genant半定量方法对DXA影像进行椎体骨折评估的一致性。方法对217例≥50岁绝经后女性作骨密度检测的同时进行胸腰椎T4~L5正侧位扫描,采用形态学定量评估方法和Genant半定量方法进行椎体骨折评估,比较二种方法确定椎体骨折的一致性和二种方法确定椎体骨折组与无椎体骨折组的临床特征。结果形态学定量评估方法确定59例椎体骨折,椎体骨折率为27.19%;Genant半定量方法确定60例椎体骨折,椎体骨折率为27.65%。kappa一致性分析,κ=0.80。二种方法确定椎体骨折组与无椎体骨折组的临床特征无统计学差异。结论 Genant半定量方法和形态学定量评估方法均是评估椎体骨折的有效方法。     

DXA影像评估绝经后女性椎体骨折

目的：做骨密度检测时,应用椎体骨折评估软件发现椎体骨折,提高椎体骨折诊断率。方法连续对217例≥50岁绝经后女性做股骨近端骨密度检测时,行胸腰椎侧位扫描,应用椎体骨折评估软件发现椎体骨折。根据骨密度T值分为T＞－2．5组和T≤－2．5组,年龄分为50～59岁组、60～69岁组和≥70岁组,绝经年限分为0～9年组、10～19年组和≥20年组,分析骨密度、年龄和绝经年限对椎体骨折率的影响,为了了解VFA对椎体骨折的评估的一致性,由同一位研究人员间隔2个月后再次对影像进行评估,采用Kappp统计方法行重复性检验。结果骨密度T＞－2．5患者椎体骨折率为21．6％,T≤－2．5患者椎体骨折率34．8％;各年龄组椎体骨折率：50－59岁为12．5％,60－69岁为25．6％,≥70岁为44．8％;绝经年限长的女性椎体骨折率显著升高。重复性检验提示一致性强度极强。结论对绝经后女性做骨密度检测时,同时进行椎体骨折评估有利于提高椎体骨折和骨质疏松诊断率。     

A multinational study to develop universal standardization of whole-body bone density and composition using GE Healthcare Lunar and Hologic DXA systems

Dual‐energy x‐ray absorptiometry (DXA) is used to assess bone mineral density (BMD) and body composition, but measurements vary among instruments from different manufacturers. We sought to develop cross‐calibration equations for whole‐body bone density and composition derived using GE Healthcare Lunar and Hologic DXA systems. This multinational study recruited 199 adult and pediatric participants from a site in the US (n = 40, ages 6 through 16 years) and one in China (n = 159, ages 5 through 81 years). The mean age of the participants was 44.2 years. Each participant was scanned on both GE Healthcare Lunar and Hologic Discovery or Delphi DXA systems on the same day (US) or within 1 week (China) and all scans were centrally analyzed by a single technologist using GE Healthcare Lunar Encore version 14.0 and Hologic Apex version 3.0. Paired t‐tests were used to test the results differences between the systems. Multiple regression and Deming regressions were used to derive the cross‐conversion equations between the GE Healthcare Lunar and Hologic whole‐body scans. Bone and soft tissue measures were highly correlated between the GE Healthcare Lunar and Hologic and systems, with r ranging from 0.96 percent fat [PFAT] to 0.98 (BMC). Significant differences were found between the two systems, with average absolute differences for PFAT, BMC, and BMD of 1.4%, 176.8 g and 0.013 g/cm², respectively. After cross‐calibration, no significant differences remained between GE Healthcare Lunar measured results and the results converted from Hologic. The equations we derived reduce differences between BMD and body composition as determined by GE Healthcare Lunar and Hologic systems and will facilitate combining study results in clinical or epidemiological studies. © 2012 American Society for Bone and Mineral Research.     

How the New Hologic Hip Normal Reference Values Affect the Densitometric Diagnosis of Osteoporosis

In February 1997, Hologic supplied new software to all QDR dual-energy X-ray absorptiometry (DXA) machines replacing the previous femoral normative reference database with the NHANES III normative data. In addition to changing the normative database (and therefore T-scores) for all regions of the hip, the new software has changed the primary region of interest from the femoral neck to the total hip. In the present study we examined how these changes influence the densitometric diagnosis of osteoporosis in a large clinical referral population (n= 2311, mean age 62.7 years). The patients had spine and hip DXA performed at either of two centers using a Hologic QDR-2000 over a 4-year period. T-scores were derived for each patient using both previous and current young normal reference databases. Intraindividual differences in T-scores were calculated. The prevalence of osteoporosis based on the two normative databases and the difference between the prevalence was calculated for each skeletal site. The average paired difference between current and previous T-scores at femoral neck is 0.64, the difference increasing with age. Using the new normative database, the percentage of osteoporotic patients decreases from 49% of all patients at the femoral neck to 28% at the femoral neck and 20% at the total hip. In conclusion, the densitometric diagnosis of osteoporosis will be affected in a significant proportion of women as a result of the implementation of the new hip normative database supplied by Hologic. Whether this will translate into fewer patients being treated remains to be seen. Received: 23 July 1997 / Accepted: 21 January 1998     

Discrimination of Patients With and Without Vertebral Fractures as Measured by Ultrasound and DXA Osteodensitometry

This study compares dual X-ray absorptiometry (DXA) measurements of the hip and spine with quantitative ultrasound (QUS) parameters measured simultaneously at the calcaneal and phalangeal bone in 174 patients with and without vertebral fractures. The aim of this study was to compare the ability of DXA and QUS measurements to discriminate patients with and without osteoporotic vertebral fractures and to evaluate whether QUS measurements in addition to the DXA measurements improve the clinical discrimination between patients with and without osteoporotic vertebral fractures. T-scores determined by DXA measurements at the spine and hip and QUS measurements at the calcaneus provide similar information regarding the discrimination of women with and without vertebral fractures. Phalangeal QUS measurements did not discriminate between patients with and without vertebral fractures. The discriminative power of the combined use of DXA and calcaneal QUS measurements to discern between patients with and without vertebral fractures increases in women. In contrast, the combined use of DXA and phalangeal QUS measurements resulted in decreased discriminative power as compared to DXA measurements alone. The number of fractures was higher in the quartiles with lower T-scores of the DXA and calcaneal QUS measurements whereas no difference was seen in the T-score quartiles of the phalangeal QUS device. These findings suggest that DXA and QUS measurements at weight-bearing skeletal sites provide useful information for assessing women with an anamnestic risk of osteoporotic bone loss. For DXA and calcaneal QUS measurements in men as well as for phalangeal QUS, however, a clinical algorithm remains to be established to understand the diagnostic implications and related therapeutic consequences of the obtained measurements.     

Analysis of four recruitment methods for obtaining normative data through a Web-based questionnaire: a pilot study

Background

Quality normative data requires a diverse sample of participants and plays an important role in the appropriate use of health outcomes. Using social media and other online resources for survey recruitment is a tempting prospect, but the effectiveness of these methods in collecting a diverse sample is unknown. The purpose of this study is to pilot test four methods of recruitment to determine their ability to produce a sample representative of the general US population.

Methods

This project is part of a larger study to gather normative data for the Michigan Hand Outcomes Questionnaire (MHQ). We used flyers, e-mail, Facebook, and an institution-specific clinical research recruitment Web site to direct participants to complete an online version of the MHQ. Participants also provided comorbidity and demographic information.

Results

The institution-specific recruitment Web site yielded the greatest number of respondents in an age distribution that mirrored the US population. Facebook was effective for recruiting young adults, and e-mail was successful for recruiting the older adults. None of the methods was successful in reaching an ethnically diverse sample.

Conclusions

Obtaining normative data that is truly representative of the US population is a difficult task. The use of any one recruitment method is unlikely to result in a representative sample, but a greater understanding of these methods will empower researchers to use them to target specific populations. This pilot analysis provides support for the use of Facebook and clinical research sites in addition to traditional methods of e-mail and paper flyers.     

老年性骨质疏松与髋部骨折

本研究采用随机分组设计比较了102名绝经后妇女中股骨颈骨折及股骨粗隆间骨折患者与正常对照组的Singh指数、股骨颈皮质骨指数和股骨外侧皮质骨厚度,结果表明两骨折组与正常对照组之间均有非常显著(P<0.01)或显著(P<0.05)之统计学差异,认为骨质疏松是老年人髋部骨折的主要影响因素之一,而采用X线平片评定股骨近端的骨量改变对于预测髋部骨折之危险性具有一定价值.     

Cross Calibration of Hologic QDR2000 and GE Lunar Prodigy for Whole Body Bone Mineral Density and Body Composition Measurements

The objective of this study was to undertake an in vivo cross calibration of body composition, whole body bone mineral content (BMC) and bone mineral density (BMD) between a Hologic QDR2000 and a GE Healthcare Lunar Prodigy. Twenty-one subjects attending for routine bone densitometry were recruited to the study (19 female and 2 male, aged 30–79 yr). Phantom cross calibrations were carried out using the Bio-Imaging Variable Composition Phantom (VCP) for percentage fat (%fat) and the Bona Fide Phantom (BFP) for BMD. There was no significant difference in whole body lean body mass between the QDR2000 and the Prodigy. Fat mass (FM) and %fat were significantly higher on the QDR2000. BMC and whole body BMD were significantly higher on Prodigy. As the BMC increased, so did the difference between the 2 instruments. The VCP did not provide an adequate cross calibration of %fat compared with in vivo. The BFP provided a good cross calibration of whole body BMD compared with in vivo. The results suggest that the partitioning of the soft tissue component between lean and fat in the 2 instruments is systematically different. The variation between instruments from the same and different manufacturers reported in the literature varies widely, as does the comparison with criterion methods. This makes it difficult to generalize the results of this study to other centers and it is recommended that each center would have to cross calibrate when changing equipment.     

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.     

Differences in hip axis and femoral neck length in premenopausal women of Polynesian, Asian and European origin

There are substantial inter-racial differences in hip fracture incidence. Studies in several different ethnic groups have suggested that differences in the length of the femoral neck may contribute to these. The present study assesses femoral neck and hip axis lengths in three ethnic groups in which it has not been documented previously (Chinese, Indians and Polynesians) and compares these values with those in Europeans. Lengths were measured from dual-energy X-ray absorptiometry scans of the proximal femur in normal premenopausal women (n=225). The Polynesian (1.65 m) and European (1.64 m) women were significantly taller than the two Asian groups (mean height in each, 1.58 m). There were also differences in mean body weight, the Polynesians being the heaviest (76 kg) and the Chinese the lightest (53 kg). Femoral neck lengths were (mean + SD) Chinese 61.5+4.4 mm, Indian 61.5+5.1 mm, Polynesian 68.2+4.3 mm and Europeans 66.0+4.8 mm. Hip axis lengths were Chinese 98.0+5.6 mm, Indian 94.5+5.2 mm, Polynesian 106.4 ± 5.3 mm and European 102.3+5.3 mm. Each of the other groups were significantly different from the Europeans for both variables and, in general, this remained so after height adjustment. These data suggest that shorter femoral necks are common to the major Asian racial groups. However, in contrast to all other ethnic groups studied, Polynesians have longer femoral necks than Europeans and their low incidence of hip fracture is not explicable, therefore, in terms of their femoral neck length. This suggests that either higher bone density or other more subtle differences in proximal femoral geometry must account for the low hip fracture incidence in Polynesians.     

Cross-calibration of liquid and solid QCT calibration standards: Corrections to the UCSF normative data

Quantitative computed tomography (QCT) has been shown to be a precise and sensitive method for evaluating spinal bone mineral density (BMD) and skeletal response to aging and therapy. Precise and accurate determination of BMD using QCT requires a calibration standard to compensate for and reduce the effects of beam-hardening artifacts and scanner drift. The first standards were based on dipotassium hydrogen phosphate (K₂HPO₄) solutions. Recently, several manufacturers have developed stable solid calibration standards based on calcium hydroxyapatite (CHA) in water-equivalent plastic. Due to differences in attenuating properties of the liquid and solid standards, the calibrated BMD values obtained with each system do not agree. In order to compare and interpret the results obtained on both systems, cross-calibration measurements were performed in phantoms and patients using the University of California San Francisco (UCSF) liquid standard and the Image Analysis (IA) solid standard on the UCSF GE 9800 CT scanner. From the phantom measurements, a highly linear relationship was found between the liquid- and solid-calibrated BMD values. No influence on the cross-calibration due to simulated variations in body size or vertebral fat content was seen, though a significant difference in the cross-calibration was observed between scans acquired at 80 and 140 kVp. From the patient measurements, a linear relationship between the liquid (UCSF) and solid (IA) calibrated values was derived for GE 9800 CT scanners at 80 kVp (IA=[1.15×UCSF]-7.32). The UCSF normative database for women and men obtained with the liquid standard was corrected for use with the solid standard. Proper procedures for cross-calibrating QCT measurements and the appropriate uses of normative data are discussed.     

Ultrasound and dual X-ray absorptiometry densitometry in women with hip fracture

To assess the usefulness of the measurement of the os calcis by ultrasound, a method that probably reflects bone quality as well as density, we have studied 54 women with hip fracture of the proximal femur and a control group. Ultrasound evaluation of the os calcis [broadband ultrasound attenuation (BUA), speed of the sound (SOS), and a combined index (stiffness)], and bone mineral density (BMD) determination over the proximal femur by dual X-ray absorptiometry (DXA) were performed. Weight, BMD, and ultrasound values in the hip fracture patients were significantly lower than controls (P<0.001). The Z-scores for BUA and stiffness were not different than that for femoral neck. Ward's triangle or trochanteric BMD (between-1.7 and -1.5). The odds ratios determined by receiver-operating characteristics (ROC) analysis were greater at the femoral neck (25.1) and BUA (24.4). Intermediate values were found at stiffness (16.9), Ward's triangle (12.8), and trochanter (11.1), and lower values were obtained at SOS (4.2). In turn, patients with trochanteric hip fractures had a significantly lower femoral neck and Ward's triangle BMD, stiffness, and BUA than patients with cervical hip fractures. Comparing a subgroup of 30 women with hip fractures without vertebral fractures with an age-matched group of 87 women with osteoporotic vertebral fractures, both groups were of similar weight and BMD but all ultrasound values were significantly lower in the hip fractures compared with vertebral fracture patients (P<0.05-P<0.01). Our findings suggest that in women with hip fractures, ultrasound evaluation of the os calcis has diagnostic sensitivity comparable to DXA of the femur and could be useful to predict hip fracture risk. Ultrasound values are lower in hip fractures compared with vertebral fracture, age-matched women and in older compared with younger hip fracture patients.     

The hospital burden of vertebral fracture in Europe: A study of national register sources

The aims of this study were to quantify the hospital burden of vertebral fracture in Europe and to compare this with that of hip fracture. Information on hospital discharges was sought by age and sex from Ministries of Health in Europe. Discharge rates for vertebral fracture, available from 12 countries, varied by more than 4-fold between countries, which was greater than the differences between sexes. Where the discharge rate was high for vertebral fracture the incidence of hip fracture was also high. Since nearly all cases of hip fracture are hospitalized, this suggests a relationship between hip and vertebral fracture risk that is not explained by different admission policies for vertebral fracture in different European countries.     

Geometric measurements of the proximal femur in UK women: Secular increase between the late 1950s and early 1990s

The aim of this study was to determine whether hip axis or femoral length has increased in women in the United Kingdom between the late 1950s and early 1990s. Such an observation would be of interest as it might explain the rise in age-specific incidence of hip fracture observed during these years. We studied two sets of antero-posterior pelvic radiographs of women aged 55–69 years taken during the course of population-based studies in the UK, one in 1958–60 and the other in 1989–91. One observer (S.G.) recorded the following measurements at the right hip: hip axis length (HAL), femoral length (FL) and femoral width (FW). Two summary ratios, HAL/FW and FL/FW were calculated to allow for differences in radiographic technique. HAL, FL and FW were greater in the 1989-91 films compared with those taken in 1958–60. Both HAL and FL expressed as a ratio to FW were also greater in the later films. FL/FW increased by 4.5% (p<0.05); HAL/FW increased by 2.3%, though this was not statistically significant. We conclude that there has been a small apparent change in geometric measurements of the hip during the past 36 years. Cautious extrapolation suggests that such a change may explain up to one third of the increase in incidence of hip fracture observed during this period.     

Broadband ultrasound attenuation and dual energy X-ray absorptiometry in patients with hip fractures: Which technique discriminates fracture risk

There is considerable interest in predicting risk of hip fracture in order to allow targeting of preventive care. This study aimed to determine which of two methods best discriminates a hip fracture population from controls. Fifty women with fractured neck of femur, and 50 control subjects were scanned using dual energy X-ray absorptiometry (DXA) of the spine and hip and broadband ultrasound attenuation (BUA) of the os calcis. Significant differences between the two populations could be found for both DXA and BUA, with BUA showing the largest percentage difference (27%). The mean z-scores showed that BUA had the lowest, with the exception of DXA trochanter. However, no significant difference between BUA and DXA trochanter Z-scores was found. A receiver operator characteristic (ROC) analysis showed that BUA has a superior sensitivity and specificity compared with DXA measurements, with DXA of the hip being better than the spine. This retrospective study shows that BUA is a better discriminator of hip fracture than DXA lumbar spine of DXA hip, which may have important implications for predicting those at risk of future hip fracture.     

老年人骨质疏松性髋部骨折与Singh指数和股骨近端几何结构的相关性初探

目的探讨老年性髋部骨折与Singh指数和股骨近端几何结构的关系。方法髋部骨质疏松骨折性46例。男24例,女22例;年龄56～82岁,平均(67.3±12.5)岁。对照组48例,为同期健康体检的志愿者,男25例,女23例;年龄54～79岁,平均(68.2±11.8)岁。测量两组受试者Singh指数及股骨颈轴长(FNAL)、颈干角(NSA)(髋部骨折组对其健侧进行检测),比较分析彼此间的相关性。结果老年性髋部骨折患者与对照组比较Singh指数明显降低,FNAL长于对照组,NSA较对照组大。结论 Singh指数和FNAL及NSA可以提高对老年性髋部骨质疏松骨折危险性的预测。