Hip Geometry Research Articles

Femoral geometry, bone mineral density, and the risk of hip fracture in premenopausal women: a case control study.

BackgroundThe purpose of this study was to determine the relationships among hip geometry, bone mineral density, and the risk of hip fracture in premenopausal women.MethodsThe 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.ResultsThe 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.ConclusionsBMD 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.

Influence of bone mineral density and hip geometry on the different types of hip fracture.

The aim of this study was to assess the influence of bone mineral density and hip geometry on the fragility fracture of femoral neck and trochanteric region. There were 95 menopausal females of age ≥ 50 years with fragility fracture of hip, including 55 cases of femoral neck fracture and 40 cases of trochanteric fracture. Another 63 non-fractured females with normal bone mineral density (BMD) were chosen as control. BMD, hip axis length, neck-shaft angle and structural parameters including cross surface area, cortical thickness and buckling ratio were detected and compared. Compared with control group, the patients with femoral neck fracture or trochanteric fractures had significantly lower BMD of femoral neck, as well as lower cross surface area and cortical thickness and higher buckling ratio in femoral neck and trochanteric region. There were no significant differences of BMD and structural parameters in the femoral neck fracture group and intertrochanteric fracture group. Hip axis length and neck-shaft angle were not significantly different among three groups. The significant changes of BMD and proximal femur geometry were present in the fragility fracture of femoral neck and trochanteric region. The different types of hip fractures cannot be explained by these changes.

Low Normal TSH levels are Associated with Impaired BMD and Hip Geometry in the Elderly.

Subclinical hyperthyroidism is known to be associated with the risk of fractures in elderly people. However, there are few studies assessing whether low normal thyroid-stimulating hormone (TSH) levels affect bone density and geometry. Here, we aimed to assess the influence of the TSH level on bone mineral density (BMD) and geometry in elderly euthyroid subjects. This was a cross-sectional cohort study. A total of 343 men and 674 women with euthyroidism were included and analyzed separately. The subjects were divided into tertiles based on the serum TSH level. The BMD and geometry were measured using dual-energy X-ray absorptiometry and a hip structural analysis program. Multiple regression analysis was used to compute the odds ratios of osteoporosis in the lower TSH tertile group and the association between geometry parameters and the TSH level. We found that the femoral neck and total hip BMDs were lower in the lower TSH tertile group. In women, the cross-sectional area and cortical thickness of the femur were negatively associated with the TSH level in all three regions (the narrow neck, intertrochanter, and femoral shaft); however, in men, these geometry parameters were significantly associated with the TSH level only in the intertrochanter region. The buckling ratio, a bone geometry parameter representing cortical instability, was significantly higher in the lower TSH tertile group in all three regions in women, but not in men. Our results indicated that lower TSH levels in the euthyroid range are related to lower BMD and weaker femoral structure in elderly women.

Radiological assessment of bone quality

Structural property of bone includes micro- or nano-structural property of the trabecular and cortical bone, and macroscopic geometry. Radiological technique is useful to analyze the bone structural property;micro-CT or synchrotron-CT is available to analyze micro- or nano-structural property of bone samples ex vivo, and multi-detector row CT(MDCT)or high-resolution peripheral QCT(HR-pQCT)is available to analyze human bone in vivo. For the analysis of hip geometry, CT-based hip structure analysis(HSA)is available aw sell se radiography and DXA-based HSA. These structural parameters are related to biomechanical property, and these assessment tools provide information of pathological changes or the effects of anti-osteoporotic agents on bone.

The Influence of Serum Uric Acid on Bone Mineral Density, Hip Geometry, and Fracture Risk: The Rotterdam Study.

The role of uric acid (UA) in skeletal metabolism remains to be unraveled. We prospectively investigated the association between UA, bone mineral density at the femoral neck (FN-BMD), hip bone geometry parameters, and incident fracture risk and examined whether the associations were modified by age and vitamin C intake. Data of 5074 participants of The Rotterdam Study, a prospective population-based cohort. Serum UA was assessed at baseline. FN-BMD was measured at baseline, and at second, third, and fourth visits of the Rotterdam Study. Hip bone geometry parameters were measured at baseline and at the second and third visits. Serum UA levels (per SD increase) were positively associated with FN-BMD (β = 0.007 g/cm(2); 95% confidence interval [CI] = 0.002-0.01), thicker cortices (β = 0.002 cm; 95% CI = 0.0003-0.002), lower bone width (β = -0.013 cm; 95% CI = -0.23 to -0.003), and lower cortical buckling ratio (β = -0.19; 95% CI = -0.33 to -0.06). The effects of UA on FN-BMD and cortical buckling ratio tended to become stronger over time. Hazard ratios and 95% CIs per SD increase of baseline UA levels for the development of any type of incident fractures, nonvertebral fractures, and osteoporotic fractures were 0.932 (0.86-0.995), 0.924 (0.856-0.998), and 0.905 (0.849-0.982), respectively. These associations were more prominent in older individuals (age, >65 y) and in participants with high intakes of vitamin C (> median). Higher levels of serum UA are associated with higher BMD (at the expense of thicker cortices and narrower bone diameters) and may be a protective factor in bone metabolism. However, interactions with age and vitamin C may be present.

The role of altered proximal femoral geometry in impaired pelvis stability and hip control during CP gait: A simulation study

Children with cerebral palsy (CP) often present aberrant hip geometry, more specifically increased femoral anteversion and neck-shaft angle. Furthermore, altered gait patterns are present within this population. This study analyzed the effect of aberrant femoral geometry, as present in subjects with CP, on the ability of muscles to control hip and knee joint kinematics. Given the specific gait deficits observed during crouch gait, increased ability to abduct, externally rotate the hip and extend the knee and hip were denoted as beneficial effects. We ran dynamic simulations of CP and normal gait using two musculoskeletal models, one reflecting normal femoral geometry and one reflecting proximal femoral deformities. The results show that the combination of aberrant bone geometry and CP-specific gait characteristics beneficially increased the ability of gluteus medius and maximus to extend the hip and knee. In contrast, the potentials of the hamstrings to extend the hip decreased whereas the potentials to flex the knee increased. These changes closely followed the observed changes in the muscle moment arm lengths. In conclusion, this study emphasizes the concomitant effect of the presence of proximal femoral deformity and CP gait characteristics on the muscle control of hip and knee joint kinematics during single stance. Not accounting for subject-specific geometry will affect the calculated muscles’ potential during gait. Therefore, the use of generic models to assess muscle function in the presence of femoral deformity and CP gait should be treated with caution.

Differential effect of predictors of bone mineral density and hip geometry in postmenopausal women: a cross-sectional study.

Osteoporosis is an important health problem in postmenopausal women. Lactation duration (LD), parity, menopause duration (MD), and body mass index (BMI) are important predictors of bone mineral density (BMD) and osteoporotic fractures in them. In addition, they have site-specific effects on BMD. Osteoporosis is especially prevalent in postmenopausal women. The aim of the study was to determine the effects of age, parity, LD, MD, and BMI on BMD at different sites and hip geometry in postmenopausal women. In this cross-sectional study, 87 women (45 years and above and at least 5 years postmenopausal) were enrolled. Subjects were divided into three parity groups (group 1: ≤ 2 children, group: 3-4 children, and group 3: > 4 children) and three LD groups (group 1: < 4 years, group 2: 4-8 years, and group 3: > 8 years). BMD was measured at neck of femur (BMD-NF), trochanter (BMD-TR), inter-trochanter (BMD-IT), spine (BMD-LS), and forearm (BMD-FA). Hip geometry was analyzed based on dual energy X-ray absorptiometry. One way ANOVA was used for comparisons of groups, and Bonferroni correction was used as post-hoc test. p value < 0.05 was considered significant. A significant difference in mean BMD was found between parity groups 1 and 3 at BMD-NF, BMD-TR, and BMD-LS, and between LD groups 1 and 3 at BMD-NF, BMD-TR, BMD-IT, and BMD-LS. Mean buckling ratio (BR) at IT was significantly different between parity groups 1 and 3, and LD groups 1 and 3. In multivariate regression analysis, BMI, age, and parity were significant predictors for BMD-NF; parity, BMI, and MD for BMD-TR; BMI, MD, and LD for BMD-IT; BMI and LD for BMD-LS; and age, LD, and BMI for BMD-FA. BMI and LD were significant predictors of IT-BR, while MD and BMI of narrow neck BR. MD, LD, parity, BMI, and age are important factors influencing BMD at hip and spine in postmenopausal women, and have site-specific effects on BMD.

Computed tomography evaluation of hip geometry restoration after total hip resurfacing

BackgroundAnatomic reconstruction of the hip is among the main requirements for hip arthroplasty to be successful. Resurfacing arthroplasty may improve replication of the native joint geometry but has been evaluated only using standard radiographs. We therefore performed a computed tomography (CT) study to assess restoration of hip geometry after total hip resurfacing (HR), comparatively with the non-operated side. HypothesisHR does not change native extra-medullary hip geometry by more than 5mm and/or 5°. Patients and methodsCT was used to evaluate unilateral HR in 75 patients with a mean age of 52.2years (range, 22–67years). The normal non-operated side served as the control in each patient. Mean follow-up was 2.5years (range, 1.9–3.1years). The primary evaluation criteria were femoral offset (FO) and femoral neck anteversion (FNA) and the secondary criteria were cup inclination angle, cup anteversion angle, and lower-limb length. ResultsFO showed a non-significant decrease (mean, −2.2mm; range, −4.5 to +3.7mm). FNA was preserved, with a difference of less than 2° at last follow-up versus the preoperative value. Cup measurements showed a mean anteversion angle of 24.8° (0.9–48.6) and mean inclination angle of 44.1° (32.1–56.3); corresponding values for the native acetabulum were 38.9° (20.5–54.8) and 24.8° (4.8–33.6). The residual lower-limb length discrepancy was less than 1mm (mean, −0.04mm [−1.2 to +1.6mm]). The mean angle between the femoral implant and the femoral neck axis was 5.4° of valgus. DiscussionOur results show that HR accurately restored the native extra-medullary hip geometry. Level of evidenceIII, prospective diagnostic case-control study.

Fracture Risk Prediction by Non-BMD DXA Measures: the 2015 ISCD Official Positions Part 1: Hip Geometry

Bone mineral density (BMD) measured by dual-energy X-ray absorptiometry is the current imaging procedure of choice to assess fracture risk. However, BMD is only one of the factors that explain bone strength or resistance to fracture. Other factors include bone microarchitecture and macroarchitecture. We now have the ability to assess some of these non-BMD parameters from a dual-energy X-ray absorptiometry image. Available measurements include various measurements of hip geometry including hip structural analysis, hip axis length, and neck-shaft angle. At the 2015 Position Development Conference, the International Society of Clinical Densitometry established official positions for the clinical utility of measurements of hip geometry. We present the official positions approved by an expert panel after careful review of the recommendations and evidence prepared by an independent task force. Each question addressed by the task force is presented followed by the official position with the associated medical evidence and rationale.

T-score Consistency between AP Spine and Hip Assessments in a Clinical Population

There have been many scientific advances in fracture risk prediction beyond bone density. The International Society for Clinical Densitometry (ISCD) convened a Position Development Conference (PDC) on the use of dual-energy X-ray absorptiometry beyond measurement of bone mineral density for fracture risk assessment, including trabecular bone score and hip geometry measures. Previously, no guidelines for nonbone mineral density DXA measures existed. Furthermore, there have been advances in the analysis of quantitative computed tomography (QCT) including finite element analysis, QCT of the hip, DXA-equivalent hip measurements, and opportunistic screening that were not included in the previous ISCD positions. The topics and questions for consideration were developed by the ISCD Board of Directors and the Scientific Advisory Committee and were designed to address the needs of clinical practitioners. Three task forces were created and asked to conduct comprehensive literature reviews to address specific questions. The task forces included participants from many countries and a variety of interests including academic institutions and private health care delivery organizations. Representatives from industry participated as consultants to the task forces. Task force reports with proposed position statements were then presented to an international panel of experts with backgrounds in bone densitometry. The PDC was held in Chicago, Illinois, USA, contemporaneously with the Annual Meeting of the ISCD, February 26 through February 28, 2015. This Executive Summary describes the methodology of the 2015 PDC on advanced measures from DXA and QCT and summarizes the approved official positions. Six separate articles in this issue will detail the rationale, discussion, and additional research topics for each question the task forces addressed.

Executive Summary of the 2015 ISCD Position Development Conference on Advanced Measures From DXA and QCT: Fracture Prediction Beyond BMD

There have been many scientific advances in fracture risk prediction beyond bone density. The International Society for Clinical Densitometry (ISCD) convened a Position Development Conference (PDC) on the use of dual-energy X-ray absorptiometry beyond measurement of bone mineral density for fracture risk assessment, including trabecular bone score and hip geometry measures. Previously, no guidelines for nonbone mineral density DXA measures existed. Furthermore, there have been advances in the analysis of quantitative computed tomography (QCT) including finite element analysis, QCT of the hip, DXA-equivalent hip measurements, and opportunistic screening that were not included in the previous ISCD positions. The topics and questions for consideration were developed by the ISCD Board of Directors and the Scientific Advisory Committee and were designed to address the needs of clinical practitioners. Three task forces were created and asked to conduct comprehensive literature reviews to address specific questions. The task forces included participants from many countries and a variety of interests including academic institutions and private health care delivery organizations. Representatives from industry participated as consultants to the task forces. Task force reports with proposed position statements were then presented to an international panel of experts with backgrounds in bone densitometry. The PDC was held in Chicago, Illinois, USA, contemporaneously with the Annual Meeting of the ISCD, February 26 through February 28, 2015. This Executive Summary describes the methodology of the 2015 PDC on advanced measures from DXA and QCT and summarizes the approved official positions. Six separate articles in this issue will detail the rationale, discussion, and additional research topics for each question the task forces addressed.

Bone Mineral Density, Spinal and Micro-Architecture (TBS Data) and Body Composition in the Older Ukranian Women with Vertebral Fragility Fractures

Bone mineral density (BMD) measured by dual-energy X-ray absorptiometry is the current imaging procedure of choice to assess fracture risk. However, BMD is only one of the factors that explain bone strength or resistance to fracture. Other factors include bone microarchitecture and macroarchitecture. We now have the ability to assess some of these non-BMD parameters from a dual-energy X-ray absorptiometry image. Available measurements include various measurements of hip geometry including hip structural analysis, hip axis length, and neck-shaft angle. At the 2015 Position Development Conference, the International Society of Clinical Densitometry established official positions for the clinical utility of measurements of hip geometry. We present the official positions approved by an expert panel after careful review of the recommendations and evidence prepared by an independent task force. Each question addressed by the task force is presented followed by the official position with the associated medical evidence and rationale.

Measurement of Hip Geometry—Technical Background

Conventional dual-energy X-ray absorptiometry images display a digital projection of the inorganic mineral mass in a scanned region. Bone mineral density software generates an average of the pixels within one or more regions. Although not used in the conventional analysis, the images also contain dimensional information limited to the plane of the image. The hip structure analysis method and that of the similar GE, Madison, WI, algorithm Advanced Hip Analysis use both the dimensional information and the mineral mass data to compute the types of dimensional properties (i.e., geometry) that are used to evaluate mechanical strength in engineering analyses. This article describes the hip structure analysis method and a somewhat cruder geometry approximation that does not require a reanalysis of the image. Limitations of the methods are discussed.

National Bone Health Alliance: A Multi-Sector Public-Private Partnership Working Together to Improve America's Bone Health

There have been many scientific advances in fracture risk prediction beyond bone density. The International Society for Clinical Densitometry (ISCD) convened a Position Development Conference (PDC) on the use of dual-energy X-ray absorptiometry beyond measurement of bone mineral density for fracture risk assessment, including trabecular bone score and hip geometry measures. Previously, no guidelines for nonbone mineral density DXA measures existed. Furthermore, there have been advances in the analysis of quantitative computed tomography (QCT) including finite element analysis, QCT of the hip, DXA-equivalent hip measurements, and opportunistic screening that were not included in the previous ISCD positions. The topics and questions for consideration were developed by the ISCD Board of Directors and the Scientific Advisory Committee and were designed to address the needs of clinical practitioners. Three task forces were created and asked to conduct comprehensive literature reviews to address specific questions. The task forces included participants from many countries and a variety of interests including academic institutions and private health care delivery organizations. Representatives from industry participated as consultants to the task forces. Task force reports with proposed position statements were then presented to an international panel of experts with backgrounds in bone densitometry. The PDC was held in Chicago, Illinois, USA, contemporaneously with the Annual Meeting of the ISCD, February 26 through February 28, 2015. This Executive Summary describes the methodology of the 2015 PDC on advanced measures from DXA and QCT and summarizes the approved official positions. Six separate articles in this issue will detail the rationale, discussion, and additional research topics for each question the task forces addressed.

Relationship of calf circumference with bone mineral density and hip geometry: a hospital-based cross-sectional study.

Calf circumference has significant predictive value for bone mineral density (BMD) at hip and spine and for fracture at spine in both genders and hence may be used as a clinical risk factor for fracture when BMD is not available. Lean muscle mass and higher regular physical ability has been shown to correlate with BMD and hip geometry. Calf circumference is an indicator of muscle mass. We examined the association of calf circumference (CC), thigh circumference (TC), and physical performances with BMD and hip geometry. Females above 45 years (at least 5 years postmenopausal) and males above 55 years were enrolled. Bilateral CC and TC were measured, and BMD was assessed at neck of femur (NF), trochanter (TR), inter-trochanter (IT), spine, and forearm. Dual energy X-ray absorptiometry scan-based hip geometry parameters were analyzed. One hundred sixteen subjects (29 males and 87 females) were enrolled. CC correlated significantly with BMD at NF, IT, TR, and spine in male and female, respectively, and at forearm in female. Multivariate regression analysis showed CC as a significant predictor of BMD (at TR, IT, NF, and spine in both genders) and fracture (at spine in both genders). CC had significant positive correlation with hip parameters-cross-sectional area; cortical thickness; and section modulus at NF, IT, and TR in both genders and negative correlation with buckling ratio at NF and IT in females. CC is a significant predictor of BMD at hip and spine and fracture at spine in both genders.

Does component alignment affect gait symmetry in unilateral total hip arthroplasty patients?

BackgroundComponent malposition in total hip arthroplasty patients has been associated with adverse clinical outcomes. However, whether the component alignment influences hip dynamic performance following total hip arthroplasty remains unclear. The purpose of this study was to investigate the relationship between the component alignment and in vivo hip kinematics during gait. MethodsNineteen unilateral total hip arthroplasty patients received CT scan for creation of 3D hip models. The component alignment between the non-implanted and implanted hips were measured and compared. Three-dimensional hip kinematics for both hips of the total hip arthroplasty patients during gait was quantified using a dual fluoroscopic imaging technique. The differences between the implanted and non-implanted hip kinematics during gait were calculated. A forward stepwise multiple linear regression was performed to evaluate the relationships between the changes in implanted hip kinematics and the differences in component alignment with respect to the non-implanted hips. FindingsAn average 5.1° (SD 6.5°; range −11.1° to 18.3°) increase in internal rotation was observed in the implanted hip than the contralateral non-implanted hip and significantly correlated with a linear combination of the increase of cup anteversion, cup medial translation and leg lengthening (R=0.81). InterpretationResults suggested that the total hip arthroplasty patients compensated the changes in hip geometry by altering the dynamic movement during gait. Restoration of the native hip geometry, including acetabular cup anteversion, position and leg length could be one of the factors that influence the hip kinematics symmetry in total hip arthroplasty patients during gait.

Bone cross-sectional geometry is not associated with atypical femoral fractures in Asian female chronic bisphosphonate users

IntroductionAtypical femoral fractures (AFF) tend to occur in Asian women with prolonged bisphosphonate exposure. Hip geometry is thought to contribute to the risk of AFF formation. We examined the hip structural geometry parameters in Asian female chronic bisphosphonate users who sustained an AFF and compared them to chronic bisphosphonate users who did not sustain any femoral fracture (NFF) and bisphosphonate-naïve patients who sustained an osteoporotic femoral fracture (OFF). Materials & methodsThirty-one patients with AFFs were gender and age-matched to 31 patients with NFFs and 49 patients with OFFs. The Hip Structural Analysis parameters analyzed were bone mineral density (BMD), cross-sectional area (CSA; a metric of resistance to axial compression), section modulus (SM; a metric of resistance to tensile loads), average cortical thickness (ACT; mean thickness of the femoral cortices), buckling ratio (BR; an index of likelihood of local buckling), and neck shaft angle (NSA; the angle between the neck and shaft axes). The regions analyzed were three cross-sections measured at the narrowest femoral neck diameter, the intertrochanteric area, and the proximal femoral shaft. One-way ANOVA with Bonferroni adjustment for multiple comparisons was used to compare parameters between the three patient groups, with statistical significance defined as p<0.05. ResultsThere were no statistical differences in parameters between patients with AFFs and patients with NFFs at all measured regions. Patients with AFFs and NFFs had statistically higher BMD, CSA, ACT, SM values and lower BR values at the NN and IT regions than patients with OFFs. Additionally, patients with NFFs had statistically higher SM values at the IT region than patients with OFFs, while patients with AFFs had statistically higher BMD, CSA, and ACT values at the FS region. All other measured parameters were not statistically different between the groups. ConclusionsChronic bisphosphonate users with and without AFFs had similar femoral structural geometries. Unlike in other populations, varus neck shaft angles were not found to be associated with AFFs in Asian female chronic bisphosphonate users. Thus, bone cross-sectional geometry is not likely to be associated with AFFs in Asian female chronic bisphosphonate users. Hip Structural Analysis does not show an increased predilection for tensile failure in AFFs.

Does haptic robot-assisted total hip arthroplasty better restore native acetabular and femoral anatomy?

The objective was to evaluate whether total hip arthroplasty (THA) using haptic robot assistance restores hip geometry better than the free-hand technique. Twelve robot-assisted and 14 free-hand unilateral THA patients underwent CT scan for three-dimensional (3D) hip models. The anteversion, inclination and hip joint centre locations of the native and implanted hips in each patient were quantified and compared. Significant increase of combined anteversion by 19.1 ± 11.7° and 23.5 ± 23.6° and decrease of cup inclination by 16.5 ± 6.0° and 10.2 ± 6.8° were observed in the robot-assisted and the free-hand THAs, respectively. Less variation in the difference of the component orientations (max 11.1 vs 18.3°) and the femoral head centre (max 4.5 vs 6.3 mm) were found in the robot-assisted group. This study demonstrated that neither robot-assisted nor free-hand THAs had fully restored native hip geometry. However, the higher precision of the robot-assisted THA suggested that it has potential utility in restoring the native hip geometry. Copyright © 2015 John Wiley & Sons, Ltd.

Hip axis length is a FRAX- and bone density-independent risk factor for hip fracture in women.

Bone mineral density (BMD) measurement from dual-energy X-ray absorptiometry (DXA) is widely used to assess skeletal strength in clinical practice, but DXA instruments can also measure biomechanical parameters related to skeletal shape. The objective of the study was to determine whether DXA-derived hip geometry measures provide information on fracture prediction that is independent of hip fracture probability determined from the fracture risk assessment tool (FRAX) algorithm. This was a retrospective registry study using BMD results for Manitoba, Canada. Women aged 40 years and older with baseline hip DXA, derived hip geometry measures, and FRAX scores (n = 50 420) participated in the study. Hospitalized hip fracture (n = 1020) diagnosed during 319 137 person-years of follow-up (median 6.4 y) was measured. Among the hip geometry measures, hip axis length (HAL) showed a consistent association with hip fracture risk when adjusted for age [hazard ratio (HR) 1.30 per SD increase, 95% confidence interval (CI) 1.22-1.38], and this was unaffected by further adjustment for BMD or FRAX score. Adjusted for FRAX score with BMD, there was a significant effect of increasing HAL quintile on hip fracture risk (linear trend P < .001); relative to quintile 1 (referent), the HR increased from 1.43 (95% CI 1.12-1.82) for quintile 2, 1.61 (95% CI 1.27-2.04) for quintile 3, 1.85 (95% CI 1.47-2.32) for quintile 4, and 2.45 (95% CI 1.96-3.05) for quintile 5. There was a modest but significant improvement in net reclassification improvement (1.5%) and integrated discrimination improvement (0.7%) indices. The effect of HAL was particularly strong among younger, nonosteoporotic women (FRAX adjusted HR 1.70 per SD increase, 95% CI 1.48-1.94). DXA-derived hip geometry measurements are associated with incident hip fracture risk, but many do not confer significant independent predictive information. HAL was found to predict hip fractures when adjusted for BMD or FRAX score and may be of clinical value in refining hip fracture risk.

Sex-specific differences in progressive glucose intolerance and hip geometry: the Baltimore Longitudinal Study of Aging.

Fracture risk is increased in type 2 diabetes mellitus (T2DM). The effect of pre-diabetes and T2DM on bone macroarchitecture and strength has not been well investigated. In this study, we show that in women only, both pre-diabetes and T2DM are associated with decreased hip bending strength and mineralization which might lead to skeletal weakness. Older men and women with T2DM are at increased risk for fracture despite normal bone mineral density (BMD). The discordance between bone quantity and skeletal fragility has driven investigation into additional determinants of fracture resistance in T2DM. Additionally, the effect of pre-diabetes on bone strength has not been well described. The aim of this study was to determine differences in bone macroarchitecture and strength, measured by hip geometry, in persons with normal glucose tolerance (NGT), impaired glucose tolerance (IGT), and T2DM. We performed cross-sectional analyses of older (age >55years) men (n = 472) and women (n = 473) participating in the Baltimore Longitudinal Study of Aging (BLSA) classified as NGT, IGT, or T2DM based on oral glucose tolerance testing. Bone strength measures included the hip geometry parameters of section modulus (Z), cross-sectional area (CSA), and buckling ratio (BR). Sex-stratified analyses were conducted using adjusted stepwise regression models. In women, IGT and T2DM were negatively associated with hip geometry parameters including mineralization in cross section (CSA, ß -0.076 and -0.073, respectively; both p < 0.05) and hip bending strength (Z, ß -0.097 and -0.09, respectively; both p < 0.05); conversely, IGT and T2DM were associated with improved compressive strength (BR, ß -0.31 and -0.29, respectively; both p < 0.05). There was no significant association between glycemic status and hip geometry in men. In women only, both IGT and T2DM were inversely associated with bone macroarchitecture and measures of bone mineralization and bending strength. The same association between worsening glycemic status and bone strength was not observed in men. These data suggest a differential effect of sex on hip geometry with evolving glucose intolerance.