Proximal Femur Geometry To Detect and Distinguish Femoral Neck Fractures from Trochanteric Fractures in Postmenopausal Women

Some proximal femur geometry (PFG) parameters, measured by dual-energy X-ray absorptiometry (DXA), have been reported to discriminate subjects with hip fracture. Relatively few studies have tested their ability to discriminate femoral neck fractures from those of the trochanter. To this end we performed a cross-sectional study in a population of 547 menopausal women over 69 years of age with femoral neck fractures (n= 88), trochanteric fractures (n= 93) or controls (n= 366). Hip axis length (HAL), neck–shaft angle (NSA), femoral neck diameter (FND) and femoral shaft diameter (FSD) were measured by DXA, as well as the bone mineral density (BMD) of the nonfractured hip at the femoral neck, trochanter and Ward’s triangle. In fractured subjects, BMD was lower at each measurement site. HAL was longer and NSA wider in those with femoral neck fractures. With logistic regression the age-adjusted odds ratio (OR) for a 1 standard deviation (SD) decrease in BMD was significantly associated at each measurement site with femoral neck fracture (femoral neck BMD: OR 1.9, 95% confidence interval (95% CI): 1.4–2.5; trochanter BMD: OR 1.6, 95% CI 1.2–2.0; Ward’s triangle BMD: OR 1.7, 95% CI 1.3–2.2) and trochanteric fracture (femoral neck BMD: OR 2.6, 95% CI 1.9–3.6; trochanter BMD: OR 3.0, 95% CI 2.2–4.1; Ward’s triangle BMD: OR 1.8, 95% CI 1.4–2.3). Age-adjusted OR for 1 SD increases in NSA (OR 2.2, 95% CI 1.7–2.8) and HAL (OR 1.3, 95% CI 1.1–1.6) was significantly associated with the fracture risk only for femoral neck fracture. In the best predictive model the strongest predictors were site-matched BMD for both fracture types and NSA for neck fracture. Trochanteric BMD had the greatest area (0.78, standard error (SE) 0.02) under the receiver operating characteristic curve in trochanteric fractures, whereas for NSA (0.72, SE 0.03) this area was greatest in femoral neck fractures. These results confirm the association of BMD with proximal femur fracture and support the evidence that PFG plays a significant role only in neck fracture prediction, since NSA is the best predictive parameter among those tested. Received: 24 April 2001 / Accepted: 1 August 2001     

Proximal Femoral Dimension in Elderly Chinese Women with Hip Fractures in Taiwan

To investigate the relationship between proximal femoral geometry and the occurrence of hip fracture, we compared the geometry of contralateral normal hips of 120 elderly Chinese women with hip fractures, including 63 femoral neck fractures (group A) and 57 intertrochanteric fractures (group B) due to minor trauma, with that of 72 normal elderly Chinese women (group C). The mean ages for group A, B and C subjects were 77.3, 79.7 and 72.9 years, respectively. The femoral neck length (NL), neck width (NW), diameter of femoral head, femoral shaft width just below the lesser trochanter, and neck–shaft angle (θ) were measured on the anteroposterior plain pelvic radiographs. The mean ± SD of NL for group A was 50.4 ± 3.3 mm; for group B, 50.6 ± 3.1 mm; and for group C, 48.8 ± 3.6 mm. Statistical analysis by ANOCOVA and regression showed that only NL of women with hip fractures was significantly longer than controls after correction for age, body height and weight (p <0.01). However, the difference in NL between group A and group B was not significant. By linear regression, the probability of fracture increased only with older age (p <0.001), longer NL (p <0.005) and lighter body weight (p <0.05). By logistic regression, each standard deviation increase in NL increased the risk of hip fracture (age-adjusted odds ratio 1.84; 95% CI, 1.11–3.06). The results confirm the relationship between proximal femoral geometry and the occurrence of hip fracture in elderly Chinese women in Taiwan. Received: 7 August 1998 / Accepted: 6 January 1999     

Hip Fracture Risk and Proximal Femur Geometry from DXA Scans

In this retrospective study of hip fracture risk evaluation from hip dual-energy X-ray absorptiometry (DXA) scans, our objectives were to determine which part of the femoral neck length contributes most to the fracture risk and to define a geometric parameter better than hip axis length (HAL) for discriminating hip fracture patients. Forty-nine Caucasian women with a nontraumatic femoral neck fracture were matched on age to 49 normal women and on both age and femoral neck bone mineral density (BMD) to 49 unfractured women. In addition to BMD, geometric parameters including neck–shaft angle, neck width and several HAL segments were evaluated by discriminant analysis to determine which was the best hip fracture discriminator. Neck–shaft angle had a limited influence on the hip fracture risk. Age-related bone loss was associated with a neck width increase in unfractured and fractured patients. HAL was significantly longer in fractured patients and was a significant discriminator between fractured patients and normal controls. HAL was not significant as a discriminator between fractured and low-BMD unfractured patients. The intertrochanter–head center distance (from the intertrochanteric line to the femoral head center) coincides with the femoral lever arm and includes no segments that adapt to BMD changes, such as the greater trochanter–intertrochanter distance. Among all tested lengths, this segment was the part of HAL that discriminated best between fractured and low-BMD unfractured patients. A longer intertrochanter–head center distance increased the risk of femoral neck fracture among low-BMD patients. Including automatic measurement of this segment in standard DXA protocols may prove useful in identifying patients at high risk for hip fracture. At present, HAL remains the easier neck length to measure, but automatic evaluation of the intertrochanter–head center distance must be a goal for future image analysis development. Received: 11 April 2001 / Accepted: 3 January 2002     

Risk Factors for Perimenopausal Fractures: A Prospective Study

This prospective study was aimed at determining the risk factors for the development of fractures in perimenopausal women. The study group (n= 3068) was comprised of a stratified population sample of women aged between 47 and 56 years. During the follow-up period of 3.6 years, 257 (8.4%) of the women sustained a total of 295 fractures. After adjustment for covariates, the relative risk (RR) of sustaining a fracture was found to be 1.4 [95% confidence interval (CI) 1.2–1.6] for a 1 standard deviation (SD) decrease in the spinal and femoral neck bone mineral density (BMD). Women with a previous fracture history were found to have an increased risk of fracture [RR 1.7 (95% CI 1.3–2.2)] and those reporting three or more chronic illnesses exhibited a RR of 1.4 (95% CI 1.0–1.9). Women not using hormone replacement therapy (HRT) had a RR of 1.5 (95% CI 1.1–2.2) for all fracture types. When osteoporotic fractures (vertebral, hip, proximal humerus and wrist fractures; n= 98) were used as an endpoint, the independent risk factors were found to be a low BMD (RR for a 1 SD decrease in both spinal and femoral neck BMD was 1.6, 95% CI 1.3–2.0), a previous fracture history (RR 1.9, 95% CI 1.3–2.9) and nonuse of HRT (RR 2.2, 95% CI 1.3–4.0). The independent risk factors for all other fractures (n = 158) were a low BMD (RR for a 1 SD decrease in the spinal BMD was 1.4, 95% CI 1.2–1.6 and in the femoral neck BMD was 1.3, 95% CI 1.1–1.5), a previous fracture history (RR 1.6, 95% CI 1.1–2.2), smoking (RR 1.8, 95% CI 1.1–2.7) and having had three or more chronic illnesses (RR 1.6, 95% CI 1.1–2.2). Weight, height, age, menopausal status, maternal hip fracture, use of alcohol, coffee consumption or dietary calcium intake were not independently associated with the development of any particular type of fracture. We conclude that the independent risk factors for perimenopausal fractures are a low bone density, previous fracture history, nonuse of HRT, having had three or more chronic illnesses and smoking, the gradient of risk being similar for spinal and femoral neck BMD measurements in the perimenopausal population. The risk factors are slightly different for perimenopausal osteoporotic than for other types of fractures. Received: 6 April 1999 / Accepted: 18 August 1999     

Predicting Fractures Using Bone Mineral Density: A Prospective Study of Long-Term Care Residents

Bone mineral density (BMD) has been shown to predict fracture risk in community-dwelling older persons; however, no comparable prospective study has been performed in the long-term care setting where the role of BMD testing is uncertain. To determine the ability of a single BMD measurement to predict the risk of subsequent fracture in long-term care residents, we designed a prospective study in a 725-bed long-term care facility. A total of 252 Caucasian nursing home residents (mean age 88 years, 74% women) were recruited between 1992 and 1998. BMD of the hip, radius or both sites was measured using dual-energy X-ray absorptiometry. Participants were followed through September 1999 for the occurrence of fracture. Cox proportional hazards regression models were constructed to determine the relationship between BMD and the risk of fracture controlling for potentially confounding variables. Sixty-three incident osteoporotic fractures occurred during a median follow-up time of 2.3 years. The multivariate-adjusted risk of fracture for each standard deviation decrease in BMD was 2.82 (95% CI 1.81–4.42) at the total hip, 2.79 (95% CI 1.69–4.61) at the femoral neck, 2.26 (95% CI 1.51–3.38) at the trochanter, 1.83 (95% CI 1.14–2.94) at the radial shaft and 1.84 (95% CI 1.21–2.80) at the ultradistal radius. Subjects in the lowest age-specific quartile of femoral neck BMD had over 4 times the incidence of fracture compared with those in the highest quartile. BMD at either hip or radius was a predictor of osteoporotic fracture, although in women, radial BMD did not predict fracture. Knowledge of BMD in long-term care residents provides important information on subsequent fracture risk. Received: 3 December 1999 / Accepted: 17 March 2000     

DXA of the Hip and Heel Ultrasound but not Densitometry of the Fingers Can Discriminate Female Hip Fracture Patients from Controls: A Comparison Between Four Different Methods

Dual-energy X-ray absorptiometry (DXA) of the proximal femur and in more recent years quantitative ultrasound (QUS) of the heel are the most established methods for assessing hip fracture risk. Measurement of the fingers offers a new approach. We performed DXA of the proximal femur, QUS of the heel and fingers, and radiographic absorptiometry (RA) of the fingers in 87 non-institutionalized women, 65–85 years of age, with a first hip fracture and compared them with 195 randomly selected age-matched controls. Bone mineral density (BMD) of the femoral neck and heel Stiffness Index were significantly lower among cases than among controls (by 15% and 17%, respectively; p<0.0001), whereas no significant differences were found for finger measurements. When applying the WHO criterion of osteoporosis, 62–98% of the patients were classified as osteoporotic, compared with 19–85% of the controls, depending on method and site. The risks of hip fracture, estimated as odds ratios for every 1 SD reduction in femoral neck BMD, heel Stiffness Index, finger QUS and finger RA, were: 3.6 (95% CI 2.4–5.5), 3.4 (95% CI 2.2–5.0), 1.0 (95% CI 0.7–1.3) and 1.2 (95% CI 0.8–1.6), respectively. Compared with women with normal BMD of the femoral neck, those classified as osteopenic had an odds ratio of hip fracture of 14 (95% CI 2-110), whereas those classified as osteoporotic had an odds ratio of 63 (95% CI 8–501). We conclude that hip DXA and heel QUS have similar capacities to discriminate the risk of a first hip fracture, whereas QUS and RA of the phalanges seem inferior techniques for differentiating female hip fracture patients from controls. Received: 10 March 2000 / Accepted: 21 September 2000     

Femoral Neck and Intertrochanteric Fractures Have Different Risk Factors: A Prospective Study

The aim of this study was to determine whether both types of hip fracture, femoral neck and intertrochanteric, have similar risk factors. A prospective cohort study was carried out on community-dwelling elderly women in four areas of the United States: Baltimore, MD; Pittsburgh, PA; Minneapolis, MN and Portland, OR. The participants were 9704 Caucasian women, 65 years and older, of whom 279 had fractured their femoral neck and 222 had fractured their trochanteric region of the proximal femur. The predictors used were the bone mass of the calcaneus and proximal femur, anthropometry, history of fracture (family and personal), medication use, functional status, physical activity and visual function. The main outcome measures were femoral neck and intertrochanteric fractures occurring during an average of 8 years of follow-up. In multivariate proportional hazards models, several risk factors increased the risk of both types of hip fracture; including femoral neck bone density and increased functional difficulty. In hazard regression models that directly compared risk factors for the two types of hip fracture, calcaneal bone mineral density (BMD) predicted femoral neck fractures more strongly than intertrochanteric fractures (OR = 1.16; 95% CI = 1.02–1.31). Steroid use and impaired functional status also predicted femoral neck fractures instead of intertrochanteric fractures. Poor health status (OR = 0.74; 95% CI = 0.55–1.00) predicted intertrochanteric fractures more strongly than femoral neck fractures. We conclude that femoral neck fractures are largely predicted by BMD and poor functional ability while aging and poor health status predispose to intertrochanteric fractures. Received: 8 February 2000 / Accepted: 10 June 2000     

Fall Characterictics, Functional Mobility and Bone Mineral Density as Risk Factors of Hip Fracture in the Community-Dwelling Ambulatory Elderly

Hip fracture is the most serious consequence of osteoporosis, frequently occurring in the elderly; however, no research has been performed to identify the fall characteristics, functional mobility and bone mineral density (BMD) concurrently as risk factors. We investigated the risk factors of hip fractures using a multifactorial approach for a further preventive strategy. This age- and sex-matched case-control study was conducted in a community-based general hospital. A total of 252 consecutive community-dwelling ambulatory elderly, aged between 65 and 85 years, were studied: 127 patients (faller with hip fracture) and 125 controls (faller without hip fracture). Body mass index (BMI), predisposing medical conditions, fall characteristics, functional mobility and BMD of the hip were evaluated by direct interview and clinical examination. In the final model of multivariate regression analysis, risk factors for hip fracture were direct hip impact (adjusted odds ratio (OR), 4.9; 95% confidence interval (CI), 2.7–8.8), previous stroke (adjusted OR, 2.9; 95% CI, 1.3–6.3), sideways fall (adjusted OR, 2.5; 95% CI, 1.6–3.9), functional mobility (a decrease of 1 SD; adjusted OR, 2.0; 95% CI, 1.1–3.5), BMI (a decrease of 1 SD; adjusted OR, 1.8; 95% CI, 1.1–2.8) and femoral neck BMD (a decrease of 1 SD; adjusted OR, 1.7; 95% CI, 1.0–2.8). The effect of risk factors remained the same in different analysis sets, and adding or removing femoral neck BMD did not change other risk factors, though BMD was significantly correlated with functional mobility and BMI. Importantly, both sideways fall and direct hip impact are independent predictors of hip fracture. From these results, we suggest a preventive strategy of hip fracture in the elderly: besides the maintenance of BMD, keeping an appropriate body weight and maintaining a physically active lifestyle might be crucial. Received: 11 January 2001 / Accepted: 6 July 2001     

Quantitative Ultrasound and Symptomatic Vertebral Fracture Risk in Chinese Women

Quantitative ultrasound (QUS) is emerging as a simple, inexpensive and noninvasive method for assessing bone quality and assessing fracture risk. We assessed the usefulness of a contact calcaneal ultrasonometer by studying normal premenopausal women (group I, n= 53), normal postmenopausal women (group II, n= 198), and osteoporotic women without (group III, n= 141) and with vertebral fractures (group IV, n= 53). The osteoporotic subjects had a T-score of the spine or hip neck bone mineral density (BMD) <−2.5 based on the local Chinese peak young mean values. When compared with postmenopausal controls, mean broadband ultrasound attenuation (BUA), speed of sound (SOS), and quantitative ultrasound index (QUI) were 26%, 2.1% and 25% lower in women with vertebral fractures (p all <0.005). The correlation coefficients between QUS parameters and BMD of the spine and hip ranged between 0.4 and 0.5. The ability of the QUS to discriminate between patients groups was determined based on the mean value of normal premenopausal women in group I. The mean T-score for women with fractures was −2.87 ± 1.02 for BUA, −2.54 ± 0.79 for SOS, −3.17 ± 0.70 for QUI, −2.65 ± 0.86 for L2–4 BMD and −2.53 ± 0.66 for hip neck BMD. After adjustment for age and body mass index, the odds ratio of vertebral fracture was 1.71 (95% CI 1.2–2.6) for each 1 SD reduction in BUA, 2.72 (1.3–5.3) for SOS, 2.58 (1.4–4.6) for QUI, 2.33 (1.6–3.3) for L2–4 BMD, 2.09 (1.37–3.20) for femoral neck BMD and 1.88 (1.34–2.92) for total hip BMD. The association between the QUS parameters and vertebral fracture risk persisted even adjustment for BMD. The area under the receiver operating characteristic curve for BUA for vertebral fracture was 0.92, for SOS, QUI, L2–4 BMD and femoral neck BMD was 0.95, and for total hip was 0.91. Received: 7 January 1999 / Accepted: 18 May 1999     

An Early-Life Femoral Shaft Fracture and Bone Mineral Density at Adulthood

High peak bone mass and density in early adulthood is an important protective factor against osteoporotic fractures in later life, but it is not known whether injuries to growing bones adversely affect the attainment of peak bone mass and density. The purpose of this study was therefore to examine with dual-energy X-ray absorptiometry the areal bone mineral density (BMD) of the injured and uninjured extremity (the femoral neck, trochanter area of the femur, distal femur, patella, proximal tibia and distal tibia), lumbar spine and distal radius of young adults with a history of an early-life femoral shaft fracture and to find out whether the fracture had affected the attainment of peak bone density of these patients. Thus, the BMD and clinical status of 41 patients (28 men, 13 women) who had sustained a femoral shaft fracture in childhood or adolescence (between 7 and 15 years of age, average 13 years before the study) were examined. The fracture had led to a statistically significant difference in BMD between the injured and uninjured side distal to the fracture site (men/women: distal femur, −3.7%/−3.9%; patella, −3.1%/−5.9%; proximal tibia, −2.0%/−4.6%; distal tibia, −3.4%/−5.2%), whereas the proximal femur did not show such differences. The male patients’ spinal BMD was significantly lower (−7.9%) than that in their age-, height- and weight-matched healthy controls. The female patients’ spinal BMD tended to be fairly comparable (−1.6%) to that of the controls (NS). In summary, this study indicates that early-life femoral shaft fracture results in a moderate (−2% to −6%) long-term side-to-side BMD difference distal to the fracture site. Patients’ spinal BMD values also tend to be lower than that of controls. Thus, a femoral shaft fracture sustained in childhood or adolescence seems to disturb somewhat the attainment of peak bone density, the important predictor of osteoporotic fractures in later life. Received: 23 December 1998 / Accepted: 1 April 1999     

Bone Mineral Density and Vertebral Fractures in Men

In women, many studies indicate that the risk of vertebral fragility fractures increases as bone mineral density (BMD) declines. In contrast, few studies are available for BMD and vertebral fractures in men. It is uncertain that the strength of the relationship between BMD and fractures is similar in magnitude in middle-aged men and in postmenopausal women. In the present study, 200 men (mean age 54.7 years) with lumbar osteopenia (T-score <−1.5) were recruited to examine the relationships between spine BMD and hip BMD and the associations of BMD with vertebral fractures. Lumbar BMD was assessed from L2 to L4, in the anteroposterior view, using dual-energy X-ray densitometry. At the upper left femur, hip BMD was measured at five regions of interest: femoral neck, trochanter, intertrochanter, Ward’s triangle and total hip. Spinal radiographs were analyzed independently by two trained investigators and vertebral fracture was defined as a reduction of at least 20% in the anterior, middle or posterior vertebral height. Spinal radiographs evidenced at least one vertebral crush fracture in 119 patients (59.5%). The results of logistic regression showed that age, femoral and spine BMDs were significant predictors of the presence of a vertebral fracture. Odds ratios for a decrease of 1 standard deviation ranged from 1.8 (1.3–2.8) for spine BMD to 2.3 (1.5–3.6) for total hip BMD. For multiple fractures odds ratios ranged from 1.7 (1.1–2.5) for spine BMD to 2.6 (1.7–4.3) for total hip BMD. In all models, odds ratios were higher for hip BMD than for spine BMD, particularly in younger men, under 50 years. A T-score <−2.5 in the femur (total femoral site) was associated with a 2.7-fold increase in the risk of vertebral fracture while a T-score <−2.5 in the spine was associated with only a 2-fold increase in risk. This study confirms the strong association of age and BMD with vertebral fractures in middle-aged men, shows that the femoral area is the best site of BMD measurement and suggests that a low femoral BMD could be considered as an index of severity in young men with lumbar osteopenia. Received: 27 October 1998 / Accepted: 22 February 1999     

How Hip and Whole-Body Bone Mineral Density Predict Hip Fracture in Elderly Women: The EPIDOS Prospective Study

We conducted a population-based cohort study in 7598 white healthy women, aged 75 years and over, recruited from the voting lists. We measured at baseline bone mineral density (BMD g/cm²) of the proximal femur (neck, trochanter and Ward's triangle) and the whole body, as well as fat and lean body mass, by dual-energy X-ray absorptiometry (DXA). One hundred and fifty-four women underwent a hip fracture during an average 2 years follow-up. Each standard deviation decrease in BMD increased the risk of hip fracture adjusted for age, weight and centre by 1.9 (95% CL 1.5, 2.3) for the femoral neck, 2.6 times (2.0, 3.3) for the trochanter, 1.8 times (1.4, 2.2) for Ward's triangle, 1.6 times (1.2, 2.0) for the whole body, and 1.3 times (1.0, 1.5) for the fat mass. The areas under the receiver operating characteristic (ROC) curves were not significantly different between trochanter and femoral neck BMD, whereas ROC curves of femoral neck and trochanter BMD were significantly better than those for Ward's triangle and whole-body BMD. emsp;Women who sustained an intertrochanteric fracture were older (84 ± 4.5 years) than women who had a cervical fracture (81 ± 4.5 years) and trochanter BMD seemed to be a stronger predictor of intertrochanteric ([RR = 4.5 (3.1, 6.5)] than cervical fractures ([RR = 1.8 (1.5, 2.3]). emsp;In very elderly women aged 80 years and more, hip BMD was still a significant predictor of hip fracture but the relative risk was significantly lower than in women younger than 80 years. emsp;In the 48% of women who had a femoral neck BMD T-score less than –2.5, the relative risk of hip fracture was increased by 3, and the unadjusted incidence of hip fracture was 16.4 per 1000 woman-years compared with 1.1 in the population with a femoral neck BMD T-score 5–1. Received: 19 May 1997 / Accepted: 16 October 1997     

Quantitative Ultrasound and Bone Densitometry to Evaluate the Risk of Nonspine Fractures: A Prospective Study

The ability of quantitative ultrasound (QUS) to estimate the risk of osteoporotic fractures was evaluated in a prospective study over a mean time of 5.47 years in 254 postmenopausal women (mean age 58.06 ± 7.67 years). Baseline measurements of ultrasound transmission velocity (UTV) and bone mineral density (BMD) were taken at the distal radius (DR). UTV was also measured at the patella (P). Fifty nonspine fractures due to minor trauma were detected during annual check-ups with an incidence of 3.59/year. Fractures occurred in older women with a lower BMD and QUS. Using Cox regression analysis the relative risk (RR) per 1 standard deviation (SD) decrease in the unadjusted QUS and BMD measurements was: BMD-DR = 3.56, 95% confidence interval (CI) 1.57–8.09; UTV-DR = 5.35, 95% CI 2.07–13.83; UTV-P = 4.49, 95% CI 2.08–9.68. The relationship between BMD and QUS variables and fracture risk persisted after adjusting for potential confounders apart from previous fractures, giving the following RR: BMD-DR = 2.99, 95% CI 1.06–8.41; UTV-DR = 3.69, 95% CI 1.18–11.49; UTV-P = 3.89, 95% CI 1.53–9.90. Correcting also for previous fractures, only UTV-P remained an effective predictor of fracture risk even after QUS measurement correction for BMD. Wrist fractures were best related to BMD-DR (RR 7.33, 95% CI 1.43–37.50) and UTV-DR (RR 10.94, 95% CI 1.10–108.45), while hip and ankle fractures were significantly associated only with UTV-P (hip: RR 32.14, 95% CI 1.83–562.80; ankle: RR 17.60, 95% CI 1.78–173.79). The combined use of BMD and QUS is a better predictor of fracture risk than either technique used separately. Comparison of the areas under the receiver operating characteristic (ROC) curves did not show differences in the ability of BMD and QUS to correctly distinguish fractures. In conclusion, QUS predicts fracture risk in osteoporotic women at least as well as BMD. UTV-DR and BMD-DR are good predictors of wrist fractures, while UTV-P is strongly related to hip and ankle fractures. QUS and BMD combined improve the diagnostic ability of each technique individually. Received: 27 April 1999 / Accepted: 3 December 1999     

Bone Mass and Structure at the Hip in Men and Women over the Age of 60 Years

Bone mass and structure at the proximal femur are important predictors of hip fracture. The aims of this study were to compare in a large sample of elderly men and women the precision of measurements of bone mass and structure at multiple sites at the proximal femur, to examine their interrelationships, to establish their relationships with age and body size, and to examine criteria for defining geometric and architectural variables in bone structure. Women (n= 336) and men (n= 141) over the age of 60 years were studied cross-sectionally. Bone mineral density (BMD) and content (BMC) at the proximal femur were measured in duplicate by dual-energy X-ray absorptiometry (DXA). Shaft and total upper femur (hip) sites in addition to femoral neck, Ward's triangle and trochanter were measured. Structural variables, measured from radiographs and from DXA images, including cortical thickness at calcar femorale, lateral cortex and mid-femur, width of the femur and medulla, Singh grade, hip and femoral axis length, femoral head and neck width and the center of mass of the femoral neck. BMD and BMC had high reproducibility and there were significant differences in reproducibility across sites. Among sites, total upper femur and shaft had the highest reproducibility. Duplicate measurements substantially improved reliability of the measurement and are recommended when the value is close to a diagnostic level or when it will be used to establish rates of change. Reproducibility of structural variables was also high except for the lateral cortex, center of mass and Singh grade. Variance due to measurement error did not change with either age or gender. Women were significantly different from men, after controlling for differences in body size, in all variables except Singh grade and medulla width. BMD and BMC were negatively related to age and positively to body size. Structural variables examined in relation to age and body size fell into two categories. The first comprised variables that were not age-related but were body-size-related, suggesting that they could be classified as geometric variables. The second comprised variables that were both body-size-related and age-related, suggesting that they could be classified as architectural variables. Using these criteria, calcar and lateral cortex were architectural variables, whereas shaft width, hip and femoral axis length, femoral head and neck width, and center of mass were geometric in both men and women. In women, shaft cortex width and medulla width were age-related, whereas in men they were not. Singh grade showed no consistent pattern with age or body size in women and men. Received: 7 January 1997 / Accepted: 7 November 1997     

Survival after Hip Fracture: Short- and Long-Term Excess Mortality According to Age and Gender

The purpose of this study was to analyze the excess mortality after hip fracture and to reveal whether, and eventually when, the excess mortality vanished in different groups of age and gender. A population-based, prospective, matched-pair, cohort study among persons 50 years of age and older was conducted involving 1338 female and 487 male hip fracture patients with 11 086 and 8141 controls respectively. Occurrence of hip fracture and mortality were recorded from 1986 until 1995. We studied the excess mortality of the hip fracture patients versus controls by using Kaplan–Meier curves and extended Cox regression with hip fracture (yes/no) as time-dependent covariate. The male hip fracture patients had higher mortality than the women the first year after the injury, irrespective of age, both in absolute terms (31% and 17% respectively) and relative to their age-matched controls. The relative risk (RR) of dying within 1 year for hip fracture patients versus controls was 3.3 (95% confidence interval (CI) 2.1–5.2) for women and 4.2 (95% CI 2.8–6.4) for men below 75 years of age. The corresponding figures for persons 85 years and older were 1.6 (95% CI 1.2–2.0) for women and 3.1 (95% CI 2.2–4.2) for men. All groups of age and gender, except women 85 years and older, had a large and significant excess mortality lasting for many years after the hip fracture – at least 5–6 years for women below 75 years of age (RR = 3.2, 95% CI 1.9–5.6). The excess mortality after hip fracture for women 85 years and older had vanished after 3 months (RR = 1.0, 95% CI 0.8–1.1). When referring to the excess mortality after hip fracture it is therefore necessary to specify sex, age and time since injury. Received: 15 September 1998 / Accepted: 23 December 1998     

The relationship between phalangeal bone density and vertebral deformities

Radiographic absorptiometry (RA) of the phalanges is a convenient and reliable technique for measuring bone mineral density (BMD). It needs only a radiograph of the hand, which can be sent for evaluation to a central facility, whereas other techniques require specialized equipment. We assessed the relationship between RA measurements and the presence of vertebral deformities in a population-based cohort of postmenopausal women, and to compare the results with simultaneously obtained BMD of the hip by dual-energy X-ray absorptiometry (DXA). A total of 389 women aged 55–84 (mean age 67.2 years, SD 8.7) were randomly selected from a large general practice. RA, DXA of the hip, and vertebral deformities in the lateral spine X-rays by vertebral morphometry were assessed. Thirty-eight women (9.8%) had severe (grade II) vertebral deformities, and their BMD at the phalanges and femoral neck was significantly lower than that of women without severe vertebral deformities. Odds ratios for the presence of severe vertebral deformities of 1.5 (95% CI: 1.1–2.1) for RA and 1.3 (95% CI: 0.9–1.9) for DXA, together with similar receiver operating characteristics curves, were found using age-adjusted logistic regression. Phalangeal BMD is related to vertebral deformities at least as closely as BMD of the femoral neck BMD. RA may therefore help to evaluate fracture risk, especially if no DXA equipment is available. Received: 21 July 1998 / Accepted: 1 July 1999     

Bone Mineral Density, Hip Axis Length and Risk of Hip Fracture in Men: Results from the Cornwall Hip Fracture Study

Bone mineral density (BMD) and hip axis length (HAL) are important determinants of fracture risk in women. There are, however, few data concerning their predictive risk in men. The aim of this study was to determine the relationship between BMD, HAL and the risk of hip fracture in men. A case–control design was used. Cases were men aged 50 years and over with a minimal-trauma hip fracture admitted to the Royal Cornwall Hospital, Truro, during 1995–1997. Controls were recruited from a large general practice within the catchment area of the hospital. Subjects were invited for assessment of BMD at the lumbar spine and proximal femur, using dual-energy X-ray absorptiometry. HAL was assessed using machine software. Data concerning BMD were available in 62 fracture cases and 100 controls. After adjusting for age, height and weight, a reduction in BMD was associated with a significant increase in the risk of hip fracture [odds ratio (OR) 1.8–4.0 per standard deviation (SD) reduction, depending on site]. HAL was similar in both fracture and control groups (12.0 cm vs 12.0 cm). After adjusting for height, there was no association between HAL and the risk of hip fracture (OR per 1 SD increase in HAL = 0.9; 95% confidence interval 0.6, 1.3). Compared with those with a cervical fracture (n= 31), those with an intertrochanteric fracture (n= 31) had lower BMD at all skeletal sites, though this was significant for the trochanteric site only. It is concluded that BMD though not hip axis length is a risk factor for low-trauma hip fracture in Caucasian men. Received: 28 September 1999 / Accepted: 21 April 2000     

Forearm Fractures as Predictors of Subsequent Osteoporotic Fractures

To assess the ability of distal forearm fractures to predict future fractures, we conducted a population-based retrospective cohort study among the 1288 residents (243 men, 1045 women) of Rochester, Minnesota age 35 years or older who experienced their first distal forearm fracture in 1975–94. During 9664 person-years of follow-up, 548 patients experienced 1109 subsequent fractures, excluding 195 that occurred on the same day as the index forearm fracture. The cumulative incidence of any subsequent fracture was 55% by 10 years and 80% by 20 years following the initial distal forearm fracture. Compared to expected fracture rates in the community, the risk of a hip fracture following the index forearm fracture was increased 1.4-fold in women (95% CI, 1.1–1.8) and 2.7-fold in men (95% CI, 0.98–5.8). In women, the risk of hip fracture differed by age, as we had found in a previous study. Women over age 70 had a 1.6-fold increase (95% CI, 1.2–2.0) in subsequent hip fracture risk whereas women who sustained their first forearm fracture before age 70 years did not have significantly increased risk. By contrast, vertebral fractures were significantly increased at all ages, with a 5.2-fold increase (95% CI, 4.5–5.9) in risk among women and a 10.7-fold increase (95% CI, 6.7–16.3) among men following a first distal forearm fracture. The increased risk in men suggests that a sentinel forearm fracture should not be ignored. Among the women, we also found a missed opportunity for intervention as hormone replacement therapy was underutilized. Received: 8 May 1998 / Accepted: 16 October 1998     

Digital X-ray Radiogrammetry Predicts Hip,Wrist and Vertebral Fracture Risk in Elderly Women: A Prospective Analysis from the Study of Osteoporotic Fractures

Digital X-ray radiogrammetry (DXR) is a technique that uses automated image analysis of standard hand radiographs to estimate bone mineral density (DXR-BMD). Previous studies have shown that DXR-BMD measurements have high precision, are strongly correlated with forearm BMD and are lower in individuals with prevalent fractures. To determine whether DXR-BMD measurements predict wrist, hip and vertebral fracture risk we conducted a case–cohort study within a prospective study of 9704 community-dwelling elderly women (the Study of Osteoporotic Fractures). We compared DXR-BMD, and BMD of the radius (proximal and distal), calcaneus, femoral neck and posteroanterior lumbar spine in women who subsequently suffered a wrist (n= 192), hip (n= 195), or vertebral fracture (n= 193) with randomly selected controls from the same cohort (n= 392–398). DXR-BMD was estimated from hand radiographs acquired at the baseline visit. The radiographs were digitized and the Pronosco X-posure System was used to compute DXR-BMD from the second through fourth metacarpals. Wrist fractures were confirmed by radiographic reports and hip fractures were confirmed by radiographs. Vertebral fractures were defined using morphometric analysis of lateral spine radiographs acquired at baseline and an average of 3.7 years later. Age-adjusted odds ratio (OR, vertebral fracture) or relative hazard (RH, wrist and hip fracture) for a 1 SD decrease in BMD were computed. All BMD measurements were similar for prediction of wrist (RH = 1.5–2.1) and vertebral fracture (OR = 1.8–2.5). Femoral neck BMD best predicted hip fracture (RH = 3.0), while the relative hazards for all other BMD measurements were similar (RH = 1.5–1.9). These prospective data indicate that DXR-BMD performs as well as other peripheral BMD measurements for prediction of wrist, hip and vertebral fractures. Therefore, DXR-BMD may be useful for prediction of fracture risk in clinical settings where hip BMD is not available. Received: 27 April 2001 / Accepted: 10 October 2001     

The use of multiple sites for the diagnosis of osteoporosis

Introduction It has been suggested that bone mineral density (BMD) measurements should be made at multiple sites, and that the lowest T–score should be taken for the purpose of diagnosing osteoporosis. Purpose The aim of this study was to examine the use of BMD measurements at the femoral neck and lumbar spine alone and in combination for fracture prediction. Methods We studied 19,071 individuals (68% women) from six prospective population-based cohorts in whom BMD was measured at both sites and fracture outcomes documented over 73,499 patient years. BMD values were converted to Z-scores, and the gradient of risk for any osteoporotic fracture and for hip fracture was examined by using a Poisson model in each cohort and each gender separately. Results of the different studies were merged using weighted β-coefficients. Results The gradients of risk for osteoporotic fracture and for hip fracture were similar in men and women. In men and women combined, the risk of any osteoporotic fracture increased by 1.51 [95% confidence interval (CI)=1.42–1.61] per standard deviation (SD) decrease in femoral-neck BMD. For measurements made at the lumbar spine, the gradient of risk was 1.47 (95% CI=1.38–1.56). Where the minimum of the two values was used, the gradient of risk was similar (1.55; 95% CI=1.45–1.64). Higher gradients of risk were observed for hip fracture outcomes: with BMD at the femoral neck, the gradient of risk was 2.45 (95% CI=2.10–2.87), with lumbar BMD was 1.57 (95% CI=1.36–1.82), and with the minimum value of either femoral neck and lumbar spine was 2.11 (95% CI=1.81–2.45). Thus, selecting the lowest value for BMD at either the femoral neck or lumbar spine did not increase the predictive ability of BMD tests. By contrast, the sensitivity increased so that more individuals were identified but at the expense of specificity. Thus, the same effect could be achieved by using a less stringent T–score for the diagnosis of osteoporosis. Conclusions Since taking the minimum value of the two measurements does not improve predictive ability, its clinical utility for the diagnosis of osteoporosis is low.