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(1) Background: The prevention of proximal femoral fractures among people of very advanced age is relevant as they are common and increasing in number. The aim of this study was to determine if the hip axis length (HAL) and the neck-shaft angle (caput–collum–diaphyseal CCD) are risk factors for those fractures among people aged 80 years and over. Consequently, it was additionally analysed if these parameters are associated with a certain fracture type. (2) Methods: Anteroposterior radiographs of the pelvis were collected to form three groups (femoral neck fractures (FNFx), trochanteric fractures (TFx) and non-fractured femora (NFx)). Two independent blinded observers separately conducted each measurement of the HAL and CCD. Statistical analysis was performed to determine the association between the measured parameters and type of fracture. (3) Results: One hundred and fifty patients (50 per group) were examined, of which the mean age was 92.7 ± 3.5 (range 81–104) years. Both the HAL and CCD of the FNFx group were significantly larger than in the TFx group (p = 0.013, 0.003). The CCD was higher in the FNFx than that of the NFx group (p = 0.001). No further significant differences of HAL and CCD were observed between the groups. (4) Conclusions: For people aged 80 years and over, an increased HAL represented no risk factor for proximal femur fractures, and a large HAL was associated with an increased occurrence of FNFx instead of TFx. A large CCD was associated with an increased risk of suffering a femoral neck fracture, showing evidence of the CCD being a risk factor for the extremely old population. [ABSTRACT FROM AUTHOR]

Background: In active elderly patients with displaced femoral neck fractures, the total hip replacement is a golden standard. However, there are also patients with high operative risk for a large surgical intervention, defined by the presence of comorbidities and the arthroplasty procedure with these patients is contraindicated. Objective: To assess the efficacy of Biplane double support screws in fixation of fracture neck of femur in elderly patients. Patients and Methods: This was prospective study that was conducted in operative rooms of Ain Shams University Hospital, twenty one elderly patients with fracture neck of femur was treated using biplane double support screws fixation. Results: Regarding garden classification of femur neck fracture, 47.6% of the patients were type 4. Regarding outcome, 10 patients were excellent, 6 patients were good, 3 patients were fair and 2 patients were poor. Mean 6 SD of Union duration is 10.59 6 1.46 weeks and only 2 cases (9.5%) complicated by Femoral head resorption. Conclusion: In elderly and in those patients who cannot afford arthroplasty or in those patients where arthroplasty is contraindicated, BDSF method is an alternate method for fixing fracture neck of femur. [ABSTRACT FROM AUTHOR]

Background Efficacy of the use of hip geometry to predict femoral neck fracture is controversial and it is influenced by the particular race. Studies on the use of hip geometry in Aceh's population have never been done. Objectives To determine the association of hip geometry with femoral neck fracture in elderly women in Dr. Zainoel Abidin Teaching Hospital. Methods This study was an observational analysis. The design of this study was cross-sectional. The study was conducted in Dr. Zainoel Abidin Teaching Hospital from May to August 2013. Hip geometry measurements were done, such as the following: hip axis length (HAL), femoral neck axis length (FNAL), femoral neck angle (FNA), and neck width (NW). Statistical analysis used was logistic regression test. Results A total of 32 patients with femoral neck fractures and 32 control patients were followed in this study. The average value of hip geometry measurements in femoral neck fracture was HAL = 90.2 ± 8.6, FNAL = 77.2 ± 7.3, FNA = 131.7 ± 6.2, NW = 32.3 ± 3.4; and in nonfemoral neck fracture, it was HAL = 88.4 ± 9.4, FNAL = 76.2 ± 7.9, FNA = 131.5 ± 7.3, NW = 29.8 ± 3.3. Measurement HAL, FNAL, and FNA did not have a significant association with the incidence of femoral neck fracture ( P > 0.05). However, NW measurement had a significant association with the incidence of femoral neck fracture ( P < 0.05). Conclusion Only NW measurement had a significant association with femoral neck fracture in older women in Dr. Zainoel Abidin Teaching Hospital. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to determine the relationships among hip geometry, bone mineral density, and the risk of hip fracture in premenopausal women.Methods: The participants in this case-control study were 16 premenopausal women with minimal-trauma hip fractures (fracture group) and 80 age-and BMI-adjusted controls. Subjects underwent dual-energy X-ray absorptiometry (DXA) to assess BMD at the proximal femur and to obtain DXA-derived hip geometry measurements.Results: The fracture group had a lower mean femoral neck and total hip BMD than the control group (0.721 ± 0.123 vs. 0.899 ± 0.115, p <0.001 for the femoral neck BMD and 0.724 ± 0.120 vs. 0.923 ± 0.116, p <0.001 for the total hip BMD). In addition, participants in the fracture group had a longer hip axis length (HAL; p = 0.007), narrower neck shaft angle (NSA; p = 0.008), smaller cross sectional area (CSA; p < 0.001) and higher cross sectional moment of inertia (CSMI; p = 0.004) than those in control group. After adjusting for BMD, the fracture group still had a significantly longer mean HAL (p = 0.020) and narrower NSA (p = 0.006) than the control group.Conclusions: BMD is an important predictor of hip fracture in premenopausal women. Furthermore, HAL and NSA are BMD-independent predictors of hip fracture in premenopausal women. Hip geometry may be clinically useful for identification of premenopausal women for whom active fracture prevention should be considered. [ABSTRACT FROM AUTHOR]

Incident hip fractures and non-hip osteoporotic fractures were studied in 30,953 women during mean 3.7 years of observation. Hip axis length (HAL) and strength index (SI) made a small but statistically significant contribution to hip fracture prediction that was independent of age and hip bone density. It is uncertain whether bone geometric measures improve fracture prediction independent of conventional areal bone mineral density (BMD). Women aged ≥50 years with hip dual-energy x-ray absorptiometry were identified from the regionally based database in the Province of Manitoba, Canada. Scans were reprocessed to derive parameters of hip bone geometry. Incident hip fractures ( N = 270) and non-hip osteoporotic fractures ( N = 1,347) were identified during mean 3.7 years of observation. HAL was greater in both hip and non-hip fracture cases than in non-fracture cases, whereas cross-sectional moment of inertia, cross-sectional area, and femoral SI were all significantly less. After adjustment for total hip BMD, HAL [hazard ratio (HR) 1.22 per SD increase, 95% CI 1.07–1.38] and SI (HR 1.21 per SD decrease, 95% CI 1.07–1.37) were independent predictors of hip fractures but not of non-hip fractures. When both HAL and SI were added to a model containing age and total hip BMD, there was a small improvement in hip fracture prediction (ROC area under the curve 0.832 ± 0.013 vs 0.823 ± 0.013; P = 0.001). HAL and SI made a small but statistically significant contribution to hip fracture prediction that was independent of age and BMD measurement. [ABSTRACT FROM AUTHOR]

In a case control study, we report that women and men with hip fractures have a longer moment arm of the force applied on the proximal femur during a sideways fall, a structural feature that may contribute to fracture risk. The impact load and its direction during a sideways fall onto the greater trochanter are partly determined by the geometry of the proximal femur. We hypothesized that the hip geometry in elderly with hip fractures produces a greater impact on the hip during a sideways fall. We studied 41 female (77.2 ± 9.9 years) and 22 male (76.2 ± 12.1 years) patients with hip fractures and 40 female (85.7 ± 6.0 years) and 17 male (84.3 ± 10.1 years) controls. Hip geometry was analyzed on the nonfracture hip in patients and left hip in controls using dual-energy X-ray absorptiometry. There was no difference in areal bone mineral density (aBMD), hip axis length, femoral neck axis length, or neck-shaft angle between cases and controls. However, the moment arm of the force on the hip during a sideways fall was 7.3% and 9.5% longer resulting in 5.6% and 9.1% greater moment in such a fall in female and male cases relative to their respective controls independent of height and weight (all p < 0.056). In multivariate logistic regression analysis, only the moment arm length in a sideways fall was associated with increased risk of hip fracture in females (odds ratio = 1.91, 95%CI: 1.14–3.20 for each SD increase in moment arm length of sideways fall, p = 0.02) and males (odds ratio = 2.69, 95% CI, 1.19–6.09, p = 0.01). A longer moment arm in the sideways fall increases the resultant force applied to the hip predisposing to hip fracture. [ABSTRACT FROM AUTHOR]

We compared hip axis length (HAL) in 157 non-Hispanic white women, 292 African-American women, and 210 Mexican-American women. After adjusting for maximal hip girth, there were no residual differences in HAL by ethnicity. Differences in hip fracture risk seen between these groups cannot be explained by ethnic differences in HAL. Hip axis length (HAL) has been reported to be an independent predictor of hip fracture. Significant ethnic differences in HAL have been noted, but no direct comparison has been made between African-American, Mexican-American, and non-Hispanic white women using the same protocol. We compared 157 non-Hispanic white women from the Rancho Bernardo Study, 292 women from the Health Assessment Study of African-American Women, and 210 women from the Skeletal Health of Mexican-American Women Project. A standardized questionnaire was used to obtain medical history; height, weight, waist girth, and hip girth were measured; and percentage body fat and HAL were obtained using dual energy X-ray absorptiometry. All HAL comparisons were adjusted for maximum hip girth to control for differences in size magnification by fan-beam absorptiometry. Though there were ethnic differences in the unadjusted HAL measurement, after adjusting for hip circumference, there were no residual differences in HAL with regard to ethnicity: 10.7 cm in Mexican-American women vs. 10.8 in non-Hispanic white women and African-American women ( p = 0.61). There were no ethnic differences in HAL in women from the three ethnic groups. Differences in fracture risk among these groups cannot be explained by ethnic differences in HAL. [ABSTRACT FROM AUTHOR]

Introduction: Proximal femoral bone strength is not only a function of femoral bone mineral density (BMD), but also a function of the spatial distribution of bone mass intrinsic in structural geometric properties such as diameter, area, length, and angle of the femoral neck. Recent advancements in bone density measurement include software that can automatically calculate a variety of femoral structural variables that may be related to hip fracture risk. The purpose of this study was to compare femoral bone density, structure, and strength assessments obtained from dual-energy X-ray absorbtiometry (DXA) measurements in a group of women with and without hip fracture. Methods: DXA measurements of the proximal femur were obtained from 2,506 women 50 years of age or older, 365 with prior hip fracture and 2,141 controls. In addition to the conventional densitometry measurements, structural variables were determined using the Hip Strength Analysis program, including hip axis length (HAL), cross-sectional moment of inertia (CSMI), and the femur strength index (FSI) calculated as the ratio of estimated compressive yield strength of the femoral neck to the expected compressive stress of a fall on the greater trochanter. Results: Femoral neck BMD was significantly lower and HAL significantly higher in the fracture group compared with controls. Mean CSMI was not significantly different between fracture patients and controls after adjustment for BMD and HAL. FSI, after adjustment for T score and HAL, was significantly lower in the fracture group, consistent with a reduced capacity to withstand a fall without fracturing a hip. Conclusion: We conclude that BMD, HAL, and FSI are significant independent predictors of hip fracture. [ABSTRACT FROM AUTHOR]

To determine the relationship between femoral neck geometry and the risk of hip fracture in post-menopausal Caucasian women, we conducted a retrospective study comparing the femoral neck dimensions of 62 hip fracture cases to those of 608 randomly selected controls. Measurements were made from dual-energy X-ray absorptiometry scans (Lunar DPX-L), using the manufacturer’s ruler function, and included: hip axis length (HAL), femoral neck axis length (FNAL), femoral neck width (FNW), femoral shaft width (FSW), medial femoral shaft cortical thickness (FSCTmed), and lateral femoral shaft cortical thickness (FSCTlat). The fracture group was older (median age 78.3 years vs 73.8 years), lighter (median weight 59.9 kg vs 64.5 kg), and, after adjustment for age, taller (mean height 158.7±0.8 cm vs 156.7±0.2 cm) than the controls. Furthermore, bone mineral density was lower in this group (0.682±0.016 g/cm2 vs 0.791±0.006 g/cm2). After adjustment for age, bone mineral content (BMC) or height, hip fracture patients had greater FNW (up to 6.6%) and FSW (up to 6.3%) than did the controls. Each standard deviation increase in FNW and FSW was associated with a 1.7-fold (95% CI 1.3–2.3) and a 2.4-fold (95% CI 1.8–3.2) increase in the fracture risk, respectively. BMC-adjusted FNAL was greater in the fracture group (+2.1%) than in the controls, while the age-adjusted FSCTmed was reduced (−7.2%). There was a trend towards longer HAL (up to 2.1%) after adjustment for age or BMC, and thinner age-adjusted FSCTlat (−1.7%) in fracture patients that did not reach statistical significance. In multivariate analysis, the risk of hip fracture was predicted by the combination of age, FNW, FSW, BMC and FSCTmed. HAL was not analyzed because of the small number of HAL measurements among fracture cases. We conclude that post-menopausal women with hip fractures have wider femoral necks and shafts, thinner femoral cortices and longer femoral neck axis lengths than do women with no fractures. Alteration in hip geometry is associated with the risk of hip fracture. [ABSTRACT FROM AUTHOR]

The discriminating ability and relevance of clinical risk factors, quantitative ultrasound (QUS) variables, X-ray-based bone mineral density (BMD) and hip axis length (HAL) measurements to evaluate the risk of osteoporotic fracture in elderly Brazilian women were examined in this study. QUS at the calcaneus (Achilles +, Lunar), HAL and BMD measurements (DPX-L, Lunar) at several anatomical sites were performed in 275 postmenopausal Caucasian women. Patients with suspected secondary osteoporosis were excluded. One hundred twenty-two (44.4%) women had had previous osteoporotic fracture. All of the subjects were over 50 years old (range 53–93) and answered a questionnaire that included details concerning aspects of lifestyle, diet, hormonal factors and drug use. Lateral thoracic and lumbar radiographs were taken and an independent radiologist reviewed the X-rays for the presence of vertebral fractures. After adjustments for age, the most relevant risk factors to discriminate patients with osteoporotic fracture from normal non-fracture controls were Stiffness index (OR 2.8 per standard deviation; 95% confidence interval 2.3, 8.7), familial history of hip fracture (OR 2.6 per standard deviation; 95% confidence interval 2.2, 5.4), femoral neck BMD (OR 2.3 per standard deviation; 95% confidence interval 1.9, 4.2), age (OR 2.1 per standard deviation; 95% confidence interval 1.6, 2.8) and weight (OR 1.9 per standard deviation; 95% confidence interval 1.5, 2.6). HAL measurements did not associate significantly with the risk of hip fracture in this population. The ability of QUS measurements discriminate between patients with fractures from those without was similar to, if not better, than X-ray-based BMD measurements. However, a combination of QUS and BMD measurements did not significantly improve fracture discrimination compared with either technique alone. Association of clinical risk factors with QUS or BMD measurements seems, on the other hand, to increase the sensibility to identify patients at risk of osteoporotic fractures. [ABSTRACT FROM AUTHOR]

The objectives of this study were to (1) obtain both femoral neck strength (FNS) and hip axis length (HAL) values from left and right femurs (regardless of hip dominance) measured by DXA and evaluate their relationship with BMD of all hip regions including total hip, (2) determine if there is a difference between dominant and nondominant hip BMD in any of the hip regions, and (3) determine how physical activity influences hip BMD. Participants were 136, generally healthy Caucasian women (57.4–88.6 years). BMD was measured by DPX-MD. Past and present activity was assessed by the Allied Dunbar National Fitness Survey for older adults and normal/brisk walking pace was measured in a straight hallway. FNS analysis uses femoral geometry to calculate stresses at the femoral neck for two loading conditions: Safety Factor Index (SF) indicates risk of fracture for forces generated during a one-legged stance, and Fall Index (FI) indicates risk of fracture for forces generated during a fall on the greater trochanter. Simple and multiple regression analyses were used to determine predictive ability of HAL, SF, and FI for respective hip BMD values. There was no statistical difference in BMD between two hips in any of the measured regions, however, the nondominant hip correlated better with other skeletal sites. Subjects with a faster normal walking speed had higher neck BMD in the nondominant hip, 0.832 ± 0.12 vs. 0.791 ± 0.10 g/cm2 (P < 0.05). Longer HAL of the left hip was negatively related to neck, trochanter, shaft, and total hip BMD. FI was significantly associated with all sites of the hip BMD, while SF was associated only with neck and wards BMC (P < 0.05). In summary: (1) a longer HAL is associated with lower BMD and a higher FI with higher BMD, (2) it might be sufficient to measure BMD in only the nondominant hip, and (3) walking at a faster pace may positively benefit femoral neck BMD. Therefore, it appears that HAL, SF, and FI all play important roles in estimating fracture risk and should be assessed along with BMD when using DXA. [ABSTRACT FROM AUTHOR]

The rate of hip fracture in Japanese women is approximately 50% lower than that of Caucasian women. Shorter hip axis length (HAL) in Japanese women is one possible explanation underlying the observed ethnic difference in fracture risk. We measured HAL in a community-based sample of Japanese (n=267) and Caucasian (n=199) women, aged 46 years on average, residing in Los Angeles, California. We hypothesized that HAL would be shorter in the Japanese women compared with the Caucasian women, and that this ethnic difference would persist after height adjustment. Unadjusted mean HAL was 101.45 mm in Japanese women and 105.98 mm in Caucasians (p<0.0001). Average height-adjusted HAL was 103.24 and 103.58 mm in Japanese and Caucasians, respectively (p=0.52). The relation between HAL and height was linear across the range of values observed in each ethnicity. Results were similar in analyses that compared Caucasians to Japanese women born in the US (n=142) or outside the US (n=125). We conclude that there was no Japanese–Caucasian difference in height-adjusted HAL in our study sample. [ABSTRACT FROM AUTHOR]

: 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. [ABSTRACT FROM AUTHOR]

: 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. [ABSTRACT FROM AUTHOR]

Hip axis length (HAL) has been proposed as an independent predictor of hip fracture risk in Caucasian females. Femoral neck axis length (FNAL) is a similar measure of femoral geometry but does not include acetabular structures. The aim of this study was to examine the association between hip geometry, using FNAL, and hip fractures in elderly males and females in relation to other anthropometric data. The study group comprised 123 females (23 hip fracture patients and 100 age-matched controls) and 137 males (13 hip fracture patients, 65 age-matched controls and 59 current-height-matched controls). All subjects had femoral neck bone mineral density measured by dual-energy X-ray absorptiometry. From these scans, FNAL was measured as the linear distance from the base of the greater trochanter to the apex of the femoral head. FNAL was correlated significantly with current height ( r = 0.47 and r = 0.56 for females and males respectively; p < 0.0001) and peak height ( r = 0.45 and r = 0.57 for females and males respectively; p < 0.0001) in both sexes. In females, FNAL in the fracture patients (91.5 ± 5.4 mm, mean ± SD) was not significantly different from FNAL in controls (89.7 ± 5.4 mm; p = 0.2). Fracture patients had the same current height as controls and a trend towards a greater peak height (163 ± 6 cm vs 160 ± cm; p = 0.09). After adjusting FNAL for current or peak height there was no difference in FNAL between fracture patients and controls. In males, FNAL in the fracture patients (103.9 ± 3.9 mm) was not significantly different from that of age-matched controls (103.4 ± 6.3 mm; p = 0.79). Fracture patients had significantly lower current height (168 ± 6 cm) than the age-matched controls (174 ± 6 cm; p = 0..0008) but had the same peak height. When adjusted for peak height there were no significant differences between height of hip fracture patients (102.0 ± 4.9 cm), age-matched controls (102.1 ± 5.1 cm) and current-height-matched controls (102.6 ± 5.3 cm). Fracture patients had a significantly greater height loss (peak height minus current height) than either control group. In logistic regression analyses peak height in females and height loss in males but no FNAL were independent predictors of hip fracture. The greater height, FNAL and presumably HAL in male versus females is not associated with increased hip fracture risk. However, in this study of elderly males and females, peak height (females) and height loss (males) were independent risk factors for hip fracture. Moreover, FNAL appears to have limited utility in the prediction of hip fracture risk and any role of HAL in the prediction of hip fracture does not relate to its major component of femoral neck length. [ABSTRACT FROM AUTHOR]

Quantitative ultrasound of the calcaneus and hip axis length are independent predictors of hip fracture and have a major genetic component. Polymorphisms of the vitamin D receptor gene (VDR) have been associated with variations in bone density in a number of studies. The aim of this study was to examine the role of VDR on other parameters associated with the risk of fracture. One hundred and eighty-nine pairs of healthy female dizygous twins were genotyped and had calcaneal ultrasound (broadband ultrasound attenuation and velocity of sound) and hip axis length measurements performed. Twin analysis using intraclass correlation coefficients and intrapair differences failed to find an association between the VDR polymorphisms and hip axis length or calcaneal ultrasound. Analysing the twins as a population, irrespective of twinning, also failed to find any association. The search for alternative genes influencing bone fragility should continue as a research priority. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Bone density predicts the risk of hip fracture. Because hip strength is determined by bone geometry and architecture as well as density, we tested which variables in geometry and architecture were independent discriminators of hip fracture and, if combined with density, improved the discrimination of fracture from non-fracture over bone density alone. The design was a case-control study. The subjects were Caucasian women over the age of 60 years who had sustained a hip fracture after the age of 58 years ( n=22), and controls matched for age and weight ( n=43) and unmatched controls ( n=317) with no history of hip fracture. Variables in density, geometry and architecture were obtained from dual-energy X-ray absorptiometry images and from radiographs of the upper end of the femur. In a univariate model, of the measures of bone mass, the best discriminator of hip fracture was bone mineral density of the neck of femur; of the geometric measurements, it was hip axis length; and of the measurements of bone architecture, it was Singh grade. In a multivariate model, these three variables were shown to be independent discriminators of hip facture. When hip axis length was combined with bone mineral density, there was significant improvement in discrimination of hip fracture ( p=0.014), and when Singh grade was combined with hip axis length and bone mineral density there was a further significant improvement ( p=0.002). In logistic regression models using hip axis length and Singh grade adjusted for femoral neck bone mineral density, age and weight, the area under the receiver-operating characteristics (ROC) curve for femoral neck density, hip axis length and Singh grade together was significantly greater than for femoral neck density alone ( p=0.006). Models that combine bone mass (density), geometry (hip axis length) and architecture (Singh grade) significantly improve the discrimination of hip fracture over bone density by itself. If these models can be shown to be equally useful in predicting hip fracture prospectively and can be obtained from dual-energy X-ray absorptiometry, their use will increase the ability to identify subjects at most risk of hip fracture. [ABSTRACT FROM AUTHOR]

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.(ABSTRACT TRUNCATED AT 250 WORDS) [ABSTRACT FROM AUTHOR]

White women have a higher rate of age-specific hip fractures than black women. Recently, femoral dimensions have been implicated in osteoporotic fractures. To study racial differences in femoral dimensions, dual X-ray absorptiometry scans were obtained for two similar groups of 50 white women and 50 black women. We measured the hip axis length (the distance from below the lateral aspect of the greater trochanter to the inner pelvic brim), the neck width and the neck/shaft angle on the scan print-out. The observer was masked to the race of the subject. The results were analyzed using the independent t-test and showed that the hip axis length and the neck width were significantly longer in the white women than in the black women ( p values <0.05 and <0.02 respectively) but that the neck/shaft angle was not statistically different in the two groups. We conclude that femoral geometry differs among races. Whether this contributes to the lower risk of hip fracture in black women will require prospectively based studies. [ABSTRACT FROM AUTHOR]

Hip axis length (HAL) has been reported as an independent risk factor for hip fracture. DEXA machines using fan beam techniques have become increasingly available. Errors in calculated hip axis length may be expected because of different degrees of magnification by the fan beam. The magnitude of this error on measurement of hip geometry was studied, using an anthropomorphic femur phantom with both fan beam (Lunar Expert and Hologic QDR-2000) and pencil beam (Lunar DPXL) densitometers. The clinical relevance of these findings was also examined using patient measurements of buttock soft tissue thickness. Femoral neck axis length (FNAL), which correlates well with HAL, was used as a measurement of hip geometry. There was a linear increase or decrease of FNAL with increasing distance of the phantom above the scanning table, when measured with the Lunar Expert or Hologic QDR-2000, respectively. There was no significant difference in FNAL at different heights using the pencil beam densitometer. The maximal difference in buttock soft tissue thickness in 30 women studied was 8.7 cm. From the equations, derived from the phantom studies, this difference would result in an 8.2% (1.4 SD) increase, or an 11.4% (1.9 SD) decrease in FNAL in the largest woman as compared with the smallest woman when measured using the Lunar Expert or Hologic QDR-2000, respectively. We conclude that there may be unpredictable degrees of magnification of FNAL in vivo, caused by differences in buttock thickness, when measured using a fan beam densitometers. Until these problems are resolved. FNAL, or related parameters of femoral geometry, should be measured using pencil beam instruments. [ABSTRACT FROM AUTHOR]