Cross-sectional Moment Of Inertia Research Articles

Association of osteoporotic fractures of femoral neck and femoral neck geometric parameters in native Chinese women

BackgroundAlthough it is generally believed that the femoral neck fracture is related to the femoral neck geometric parameters (FNGPs), the association between the risk of osteoporotic fracture of the femoral neck and FNGPs in native Chinese women is still unclear.MethodsA total of 374 female patients (mean age 70.2 ± 9.32 years) with osteoporotic fracture of the femoral neck, and 374 non-fracture control groups were completely matched with the case group according to the age ratio of 1:1. Using DXA bone densitometer to measured eight FNGPs: the outer diameter (OD), cross-sectional area (CSA), cortical thickness (CT), endocortical diameter (ED), buckling ratio (BR), section modulus (SM), cross-sectional moment of inertia (CSMI), and compressive strength index (CSI) at the narrowest point of the femoral neck.ResultsCompared with the control group, the average values of OD (2.9%), ED (4.5%), and BR (26.1%) in the patient group significantly increased (p = 0.015 to < 0.001), while CSA (‒15.3%), CT (‒18.2%), SM (‒10.3%), CSMI (‒6.4%), and CSI (‒10.8%) significantly decreased (all p < 0.001). The prevalence of osteoporosis in the lumbar spine, femoral neck, and total hip was, respectively, 82%, 81%, and 65% in fracture patients. Cox proportional hazard model analysis showed that in the age adjusted model, the fracture hazard ratio (HR) of CSA, CT, BR, SM, and CSI significantly increased (HRs = 1.60‒8.33; 95% CI = 1.08‒16.6; all p < 0.001). In the model adjusted for age and femoral neck BMD, HRs of CT (HRs = 3.90‒8.03; 95% CI = 2.45‒15.1; all p < 0.001) and BR (HRs = 1.62‒2.60; 95% CI = 1.20‒5.44; all p < 0.001) were still significantly increased.ConclusionThese results suggest that the majority of osteoporotic fractures of the femoral neck of native Chinese women occur in patients with osteoporosis. CT thinning or BR increase of FNGPs may be independent predictors of fragility fracture of femoral neck in native Chinese women unrelated to BMD.

Tibial Bone Co-Morbidities Following Volumetric Muscle Loss Injury and Physical Inactivity

Volumetric muscle loss (VML) injuries are a traumatic loss of muscle, limiting regenerative potential and resulting in chronic loss of function. In isolation the bone adjacent to the VML injury is often overlooked, but known association between the tissues are important to long-term health and function. Recent work suggests decrements in both bones and muscles of VML-injured limbs, as well as a distinct relationship between VML and bone health. The clinically injured VML population is expected to undergo considerable periods of physical inactivity or a long-term sedentary lifestyle, and thus decreased loading, after VML. Our objective was to investigate the concomitant impact of VML on the adjacent bone, with and without the restriction of physical activity (reduced ~50% of daily ambulation). We hypothesized that with restriction of physical activity, the tibia adjacent to the VML would have functional impairments greater than those with normal physical activity (daily ambulation &gt;1km). Adult male C57BI/6J mice (n=41) underwent unilateral VML to the posterior hindlimb compartment or served as uninjured age-matched controls, then were randomized to standard or restricted activity cages for 8-wks. Terminally (age 20-wks), mice underwent in vivo muscle function testing. Adjacent tibia were assessed for strength, mid‐diaphysis cortical geometry, and intrinsic material properties, and the metaphyseal trabecular bone structure was evaluated by microcomputed tomography and three‐point bending. A subset of tibias was saved for histologic staining (H&amp;E, TRAP). Data were evaluated by two-way ANOVA. There were no absolute or normalized functional muscle deficits following 8-wks of inactivity. That said, there were significant VML-functional deficits (~42% of uninjured) that are not exacerbated by inactivity (p&lt;0.001). Cortical geometric changes in the bone were primarily a result of physical inactivity, with thickness and cross-sectional moment of inertia both diminished independent of injury (p≤0.018). However, there were no differences in cortical bone volume, diameter, or cross-sectional area (p≥0.056). Trabecular bone mineral density was lower in all VML-injured tibias compared to uninjured (p=0.003). While there was no difference across groups for trabecular spacing (p&gt;0.397), there was a reduction in bone mineral density across all VML-injured, compared to uninjured tibias (p=0.003). The functional capacity of the tibia to resist fracture (i.e., ultimate load during 3‐point bending) was ~21% lower with inactivity (p=0.018), while there was only a trend for VML injury to impact resistance to fracture. Stiffness was calculated during the onset to ultimate load and ~15% less in the VML injured and inactivity VML tibias (p=0.016). Tibia of VML injured and inactive groups appear to have greater lipid accumulation compared to uninjured tibias. While discordant with muscle function, physical activity restriction with and without VML injury impairs adjacent tibia. Inactivity alone had the greatest impact on the cortical bone properties, while VML with and without physical inactivity impacted trabecular tibia properties. This study demonstrates the impact of VML with and without physical inactivity on the tibia, furthering the complexity of traumatic injury on the musculoskeletal system. W81XWH‐20‐10885 (JAC &amp; SMG); S10OD025177. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Differential effects of teriparatide, denosumab and zoledronate on hip structural and mechanical parameters in osteoporosis; a real-life study.

The aim of this study was to evaluate changes in hip geometry parameters following treatment with teriparatide (TPD), denosumab (Dmab) and zoledronate (ZOL) in real-life setting. We studied 249 patients with osteoporosis (OP) with mean [SD] age of 71.5 [11.1] years divided into 3 treatment groups; Group A received TPD; n = 55, Group B (Dmab); n = 116 and Group C (ZOL); n = 78 attending a routine metabolic bone clinic. Bone mineral density (BMD) was measured by DXA at the lumbar spine (LS), total hip (TH) and femoral neck (FN) prior to treatment and after 2years (Group A), after a mean treatment duration of 3.3 [1.3] years (Group B) and after 1, 2 and 3 doses of ZOL (Group C) to assess treatment response. Hip structural analysis (HSA) was carried out retrospectively from DXA-acquired femur images at the narrow neck (NN), the intertrochanter (IT) and femoral shaft (FS). Changes in parameters of hip geometry and mechanical strength were seen in the following treatment. Percentage change in cross-sectional area (CSA): 3.56[1.6] % p = 0.01 and cross-sectional moment of inertia (CSMI): 4.1[1.8] % p = 0.029 increased at the NN only in Group A. Improvement in HSA parameters at the IT were seen in group B: CSA: 3.3[0.67]% p < 0.001, cortical thickness (Co Th): 2.8[0.78]% p = 0.001, CSMI: 5.9[1.3]% p < 0.001, section modulus (Z):6.2[1.1]% p < 0.001 and buckling ratio (BR): -3.0[0.86]% p = 0.001 with small changes at the FS: CSA: 1.2[0.4]% p = 0.005, Z:1.6 [0.76]%, p = 0.04. Changes at the IT were also seen in Group C (after 2 doses): CSA: 2.5[0.77]% p = 0.017, Co Th: 2.4[0.84]% p = 0.012, CSMI: 3.9[1.3]% p = 0.017, Z:5.2[1.16]% p < 0.001 and BR: -3.1[0.88]% p = 0.001 and at the NN (following 3 doses): outer diameter (OD): 4.0[1.4]% p = 0.0005, endocortical diameter(ED): 4.3[1.67% p = 0.009, CSA:5.2[1.8]% p = 0.003, CSMI: 9.3[3.8]% p = 0.019. Analysis of the effect of OP therapies on hip geometry is useful in understanding the mechanisms of their anti-fracture effect and may provide additional information on their efficacy.

The effects of abaloparatide on hip geometry and biomechanical properties in Japanese osteoporotic patients assessed using DXA-based hip structural analysis: results of the Japanese phase 3 ACTIVE-J trial

SummaryDaily subcutaneous injection of 80 μg abaloparatide increased bone mineral density in Japanese patients with osteoporosis at high fracture risk in the ACTIVE-J trial. Dual-energy X-ray absorptiometry–based hip structural analysis from ACTIVE-J data showed improved hip geometry and biomechanical properties with abaloparatide compared with placebo.PurposeAbaloparatide (ABL) increased bone mineral density (BMD) in Japanese patients with osteoporosis at high fracture risk in the ACTIVE-J trial. To evaluate the effect of ABL on hip geometry and biomechanical properties, hip structural analysis (HSA) was performed using ACTIVE-J trial data.MethodsHip dual-energy X-ray absorptiometry scans from postmenopausal women and men (ABL, n = 128; placebo, n = 65) at baseline and up to week 78 were analyzed to extract bone geometric parameters at the narrow neck (NN), intertrochanteric region (IT), and proximal femoral shaft (FS). Computed tomography (CT)-based BMD and HSA indices were compared between baseline and week 78.ResultsABL treatment showed increased mean percent change from baseline to week 78 in cortical thickness at the NN (5.3%), IT (5.3%), and FS (2.9%); cross-sectional area at the NN (5.0%), IT (5.0%), and FS (2.6%); cross-sectional moment of inertia at the NN (7.6%), IT (5.1%), and FS (2.5%); section modulus at the NN (7.4%), IT (5.4%), and FS (2.4%); and decreased mean percent change in buckling ratio (BR) at the IT (− 5.0%). ABL treatment showed increased mean percent change in total volumetric BMD (vBMD; 2.7%) and trabecular vBMD (3.2%) at the total hip and decreased mean percent change in BR at femoral neck (− 4.1%) at week 78 vs baseline. All the changes noted here were significant vs placebo (P < 0.050 using t-test).ConclusionA 78-week treatment with ABL showed improvement in HSA parameters associated with hip geometry and biomechanical properties vs placebo.Trial registrationJAPIC CTI-173575

The effect of zoledronic acid on hip geometry in renal transplant recipients: a double-blind placebo-controlled randomized study

BackgroundIn renal transplant patients, bisphosphonates may prevent bone loss, but little is known about their effects on bone microarchitecture and geometrical hip parameters, as the key factors of bone stability. This study aimed to analyze the effect of zoledronic acid on the mentioned parameters in kidney transplant patients.MethodsIn this double-blind, randomized trial, 33 patients were followed for six months after administering either 4mg of zoledronic acid or a placebo. Bone mineral density (BMD) measurement of the spine, hip, radius, and whole body was obtained, and trabecular bone score (TBS) was evaluated using the software. Geometric assessment at the proximal femur was performed by the HSA program.ResultsEighteen patients in the intervention group and 15 in the control group completed the study. The mean percentages of the changes in the BMD at the lumbar spine and whole body were significantly different between the placebo and intervention groups (-0.23% vs. 4.91% and -2.03% vs. 1.23%) (P < 0.05). Zoledronic acid appeared to enhance the subperiosteal diameter, endocortical diameter, and cross-sectional moment of inertia (CSMI) at the narrow neck in comparison with placebo (P < 0.05); however, no difference in TBS was observed between both groups (P > 0.05).ConclusionsWe concluded that a single administration of zoledronic acid might ameliorate bone loss at the lumbar spine and the whole body and maintain the subperiosteal diameter, endocortical diameter, and CSMI as parameters of bone strength at the narrow neck of the proximal femur after six months in renal-transplant recipients.Trial registrationThis study was registered in IRCT (ID: IRCT20181202041821N1) on 04–05-2019.

Illicit drug use is associated with lower bone mineral density and bone strength

ObjectivesTo evaluate the association of illicit drug use with bone mineral density (BMD) and hip geometric parameters at the narrow neck. MethodsThis is a cross-sectional matched cohort study conducted in the Hong Kong Chinese population. Associations with illicit drug use were estimated using linear regression for BMD (lumbar spine and femoral neck) and hip geometrical parameters (cross-sectional area [CSA], cross-sectional moment of inertia [CSMI], section modulus [SM], average cortical thickness [ACT] and BMD at the narrow neck) after adjusting for age, body mass index (BMI), smoking status, drinking status, physical activity, and history of antipsychotic and antidepressant use. Mean difference and 95% confidence intervals (95% CI) were calculated between 108 illicit drug users and 108 controls using an adjusted linear model and cluster-robust standard errors after matching by age and sex. The false discovery rate was used to correct for multiple testing. ResultsIllicit drug users had a significantly lower BMD (g/cm2) at the lumbar spine (mean difference: −0.062; 95% CI: −0.108 to −0.015), and femoral neck (mean difference: −0.058; 95% CI: −0.106 to −0.010) in the fully adjusted model. Illicit drug users also had a significantly lower CSA (mean difference: −0.238 cm2; 95% CI: −0.462 to −0.013), ACT (mean difference: −0.018 cm; 95% CI: −0.030 to −0.006) and BMD (mean difference: −0.070 g/cm2; 95% CI: −0.128 to −0.012) at the narrow neck. ConclusionsIllicit drug use is associated with lower BMD and bone strength. Future studies evaluating the risk of illicit drug use with fragility fracture are warranted.

Associations of Type 2 Diabetes, Body Composition, and Insulin Resistance with Bone Parameters: The Dubbo Osteoporosis Epidemiology Study.

Type 2 diabetes (T2D) may be associated with increased risk of fractures, despite preserved bone mineral density (BMD). Obesity and insulin resistance (IR) may have separate effects on bone turnover and bone strength, which contribute to skeletal fragility. We characterized and assessed the relative associations of obesity, body composition, IR, and T2D on bone turnover markers (BTMs), BMD, and advanced hip analysis (AHA). In this cross-sectional analysis of Dubbo Osteoporosis Epidemiology Study, 525 (61.3% women) participants were grouped according to T2D, IR (homeostasis model assessment insulin resistance [HOMA-IR] </≥2.5), and BMI (</≥25 kg/m2): insulin-sensitive lean (IS-L), insulin-sensitive overweight/obese (IS-O), insulin-resistant (IR), and T2D. BMD, AHA, and body composition, including visceral adipose tissue (VAT) (on dual-energy x-ray absorptiometry scan) and fasting BTMs, were assessed. Analyses performed using Bayesian model averaging and principal component analysis. T2D was associated with low BTMs (by 26%-30% [95% confidence interval [CI] 11%-46%] in women, 35% [95% CI 18%-48%] in men compared to IS-L), which persisted after adjustment for VAT. BTMs were similar among IR/IS-O/IS-L. BMD was similar among T2D/IR/IS-O; BMD was low only in IS-L. All groups were similar after adjustment for BMI. Similarly, AHA components were lowest in IS-L (attenuated following adjustment). On multivariate analysis, T2D was independently associated with BTMs. IR was also associated with C-terminal telopeptide of type 1 collagen in men. Age and body size were the strongest independent contributors to BMD and AHA. VAT was inversely associated with section modulus, cross-sectional area, cross-sectional moment of inertia in women, and hip axis length in men. Low bone turnover is associated with T2D and IR (in men), while BMD and hip strength/geometry are predominantly associated with body size. VAT, indicative of dysglycemia, is also associated with impaired bone geometry. Establishing the role of BTMs and AHA fracture risk may improve skeletal assessment in T2D people. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

The Effects of a 1-Year Recreational Football Protocol on Bone Health Parameters in a Group of Healthy Inactive 50-Year-Old Men

The main aim of the current study was to explore the effects of a 1-year recreational football protocol on bone health parameters (bone mineral content (BMC), bone mineral density (BMD), femoral neck geometry and composite indices of femoral neck strength) in a group of healthy inactive 50-year-old men. 51 middle-aged men voluntarily participated in this study, but only 41 of them completed it. Thus, the study population included 11 former football (FF) players and 30 inactive men. Inactive men were assigned to 3 different groups: controls (n=10), recreational football 30 (RF30; n=10) and recreational football 60 (RF60; n=10). The RF30 group performed two sessions of recreational football per week; the duration of each session was 30 minutes. The RF60 group performed two sessions of recreational football per week; the duration of each session was 60 minutes. The current study has demonstrated that whole body (WB) BMC, femoral neck BMD, cross-sectional moment of inertia, compression strength index, bending strength index and impact strength index increased in both experimental groups (RF30 and RF60) but not in the control group. The percentages of variations in bone health parameters were not significantly different between RF30 and RF60. In conclusion, this study suggests that recreational football is an effective method to improve bone health parameters in middle-aged men. In the studied population, most of the bone health benefits occurred after a low volume training protocol (2 * 30 minutes of recreational football per week).

The Effect of Omega-9 on Bone Viscoelasticity and Strength in an Ovariectomized Diet-Fed Murine Model.

Few studies have investigated the effect of a monosaturated diet high in ω-9 on osteoporosis. We hypothesized that omega-9 (ω-9) protects ovariectomized (OVX) mice from a decline in bone microarchitecture, tissue loss, and mechanical strength, thereby serving as a modifiable dietary intervention against osteoporotic deterioration. Female C57BL/6J mice were assigned to sham-ovariectomy, ovariectomy, or ovariectomy + estradiol treatment prior to switching their feed to a diet high in ω-9 for 12 weeks. Tibiae were evaluated using DMA, 3-point-bending, histomorphometry, and microCT. A significant decrease in lean mass (p = 0.05), tibial area (p = 0.009), and cross-sectional moment of inertia (p = 0.028) was measured in OVX mice compared to the control. A trend was seen where OVX bone displayed increased elastic modulus, ductility, storage modulus, and loss modulus, suggesting the ω-9 diet paradoxically increased both stiffness and viscosity. This implies beneficial alterations on the macro-structural, and micro-tissue level in OVX bone, potentially decreasing the fracture risk. Supporting this, no significant differences in ultimate, fracture, and yield stresses were measured. A diet high in ω-9 did not prevent microarchitectural deterioration, nevertheless, healthy tibial strength and resistance to fracture was maintained via mechanisms independent of bone structure/shape. Further investigation of ω-9 as a therapeutic in osteoporosis is warranted.

Dynamic modeling and vibration analysis of cracked rotor-bearing system based on rigid body element method

Rotor crack occurs frequently in rotating machinery. It is of great significance to study the vibration mechanisms of the cracked rotor-bearing system, which can provide proofs for crack online monitoring. In this paper, a new dynamic model of the cracked rotor-bearing system is developed using the rigid body element (RBE) method, and vibration response analysis is then carried out. The rotor is discretized as a set of RBEs, and each two adjacent RBEs is connected by an elastic joint (EJ). Each EJ is modeled with six imaginary springs (three translational springs and three rotational springs). The breathing crack is modeled through time-varying stiffnesses of imaginary springs, which are obtained using real-time parameters (area, cross-section moment of inertia, and polar moment of inertia) in four processes (crack fully closed, crack partially opened, crack fully opened, and crack partially closed) in a full rotation angle. The interactions of adjacent RBEs are then given based on the force and moment analysis, and the bearing forces are obtained based on two models (i.e., equivalent spring-damper model, and Gupta bearing model). The equations of motions of the cracked rotor-bearing system are developed through Newton-Euler equations and solved by the fourth-order Runge-Kutta-Fehlberg method with a step-changing criterion. The displacement responses are then obtained, and the frequency spectrums of displacement responses and their instantaneous frequencies (IFs) under different rotation speeds are analyzed. Simulation results of the cracked rotor-bearing system are in good agreement with previously published results and experiment results. What’s more, analysis results show that the frequency spectrum of IF can be an indicator for online monitoring of the rotor crack.

Assessment of DXA derived bone quality indexes and bone geometry parameters in early breast cancer patients: A single center cross-sectional study

BackgroundBone mineral density (BMD) lacks sensitivity in individual fracture risk assessment in early breast cancer (EBC) patients treated with aromatase inhibitors (AIs). New dual-energy X-ray absorptiometry (DXA) based risk factors are needed. MethodsTrabecular bone score (TBS), bone strain index (BSI) and DXA parameters of bone geometry were evaluated in postmenopausal women diagnosed with EBC. The aim was to explore their association with morphometric vertebral fractures (VFs). Subjects were categorized in 3 groups in order to evaluate the impact of AIs and denosumab on bone geometry: AI-naive, AI-treated minus (AIDen-) or plus (AIDen+) denosumab. ResultsA total of 610 EBC patients entered the study: 305 were AI-naive, 187 AIDen-, and 118 AIDen+. In the AI-naive group, the presence of VFs was associated with lower total hip BMD and T-score and higher femoral BSI. As regards as bone geometry parameters, AI-naive fractured patients reported a significant increase in femoral narrow neck (NN) endocortical width, femoral NN subperiosteal width, intertrochanteric buckling ratio (BR), intertrochanteric endocortical width, femoral shaft (FS) BR and endocortical width, as compared to non-fractured patients. Intertrochanteric BR and intertrochanteric cortical thickness significantly increased in the presence of VFs in AIDen- patients, not in AIDen+ ones. An increase in cross-sectional area and cross-sectional moment of inertia, both intertrochanteric and at FS, significantly correlated with VFs only in AIDen+. No association with VFs was found for either lumbar BSI or TBS in all groups. ConclusionsBone geometry parameters are variably associated with VFs in EBC patients, either AI-naive or AI treated in combination with denosumab. These data suggest a tailored choice of fracture risk parameters in the 3 subgroups of EBC patients.

Effect of age on femur whole-bone bending strength of mature rat

BackgroundSkeletally mature rodents are frequently used in studies of bone health and bone healing, some of them requiring longitudinal observations that span a significant portion of the animals' adulthood. However, changes in whole bone mechanics associated with the natural aging of adult rats have not been extensively characterized. MethodsFemurs from skeletally mature Wistar rats in three age groups of 24-week (young adult), 39-week (middle-age), and 54-week (late middle-age) were tested under three-point bending load in the anterior-posterior direction. Mechanical properties and geometric properties of the femurs from the two older groups were compared to the 24-week rats. FindingsSignificantly greater strength, rigidity, and post-yield deformation were found in the 54-week group when compared to the 24-week group. The oldest group also demonstrated greater leg length, anteroposterior width, and cross-sectional moment of inertia over the youngest group. Of the intrinsic properties, the highest ultimate stress was found in the 39-week and was significantly higher than the 24-week group. The ultimate strain increased with age, and the difference between the youngest and the oldest group was statistically significant. InterpretationThe results suggest that femoral bending properties and geometric properties are continually modified from young adult to late-middle-aged animals. Knowing the baseline bone strength and rigidity throughout adulthood of a rodent breed helps guide animal selection in study design.

Reduced trabecular bone mineral density and thinner cortices in men with distal forearm fractures.

Men with distal forearm fractures have reduced bone density, an increased risk of osteoporosis and of further fractures. The aim of the study was to investigate the structural determinants of these observations using quantitative CT (qCT). Ninety six men with low-trauma distal forearm fracture and 101 age-matched healthy control subjects were recruited. All subjects underwent a quantitative CT on a standard 64-slice whole body CT scanner. These were analysed on Mindways QCT PRO™ Software to generate volumetric and geometric data at the lumbar spine, femoral neck and total hip, ultra-distal and distal 33% radius. Biochemical investigations, health questionnaires and measurements of bone turnover were made. Men with fracture had significantly lower total and trabecular vBMD at all sites. The greatest percentage reduction was at the ultra-distal radius (13.5% total and 11.7% trabecular vBMD). In the fracture group cortical vBMD was significantly higher in the femoral neck (p<0.001) and maintained at the ultra-distal radius compared with control subjects. However, cortical cross-sectional area (CSA) and thickness were significantly reduced at the femoral neck (p<0.001 and p=0.002 respectively) and forearm sites (CSA ultradistal radius p=0.001, cortical thickness p=0.002, CSA distal one third radius p=0.045 and cortical thickness p=0.005). Cross sectional moment of inertia (CSMI) and section moduli were significantly reduced at the femoral neck (CSMI1 p=0.002, CSMI2 p=0.012 and section moduli Z1 p<0.001, Z2 p=0.004) and the ultra-distal radius (CSMI1 p=0.008 and section moduli Z1 p=0.018, Z2 p=0.007). In stepwise logistic regression analysis distal forearm fracture showed the strongest association with a model comprising ultra-distal forearm trabecular vBMD (negative), procollagen type I N-terminal propeptide (PINP, positive) and sex hormone binding globulin (SHBG, negative). In conclusion, these observations explain the structural reasons for the increased fracture risk in men with distal forearm fractures.

Positive association of lean mass and negative association of protein intake on bone mass and bone geometry of adolescent soccer players

ObjectiveThe aim of this study was to evaluate the association of food consumption and body composition on bone parameters in adolescent soccer players. MethodsThere were 148 male soccer players 12 to 18 y who participated in the study. Body composition was assessed by dual energy x-ray absorptiometry, comprising bone mineral density (BMD) and bone mineral content (BMC) of total body without head (TBLH), lumbar spine (L1-L4), and right femoral neck (RFN). The bone geometry variables measured were femoral strength index (FSI), buckling ratio (BR), section modulus (Z), cross-sectional moment of inertia (CSMI), and cross-sectional area (CSA). Food intake was analyzed using the 24-h food recall. Somatic maturation was estimated by the peak height velocity equation. For the statistical analysis, the stepwise multiple linear regression was used, with P < 0.05. ResultsRegarding food consumption, there was a high protein intake and low calcium intake. Lean mass was a predictor of BMC of TBLH (R2 = 0.524), L1-L4 (R2 = 0.492), and RFN (R2 = 0.405); BMD of L1-L4 (R2 = 0.407) and RFN (R2 = 0.27); Z (R2 = 0.683), CSMI (R2 = 0.630), and CSA (R2 = 0.640). There was a negative correlation between protein intake with bone mass and bone geometry parameters. ConclusionIn adolescent soccer players, lean mass was a predictor of bone parameters, and high protein intake was negatively associated with bone mass and geometry.

Triglyceride Glucose-Body Mass Index Is a Reliable Indicator of Bone Mineral Density and Risk of Osteoporotic Fracture in Middle-Aged and Elderly Nondiabetic Chinese Individuals.

(1) Background: This study aimed to investigate the relationship of triglyceride glucose–body mass index (TyG-BMI) with bone mineral density (BMD), femoral neck geometry, and risk of fracture in middle-aged and elderly Chinese individuals. (2) Methods: A total of 832 nondiabetic individuals were selected from the prospective population-based HOPE cohort. All individuals underwent DXA for assessment of BMD at the lumbar spine, femoral neck, and total hip, as well as femoral neck geometry. The 10-year probabilities of both major osteoporotic (MOFs) and hip fractures (HFs) were calculated. (3) Results: Cortical thickness, compression strength index, cross-sectional moment of inertia, cross-sectional area, section modulus, and 25(OH)D levels were significantly lower in women (all p < 0.001). The presence of osteoporosis was related to age, BMI, BMD and femoral neck geometry, TyG-BMI, MOF, and HF. TyG-BMI was positively correlated with BMD. In men, TyG-BMI showed significant negative correlation with HF but not with MOF, the correlation exists only after adjusting for other variables in women. Femoral neck geometries were significantly impaired in individuals with low TyG-BMI. (4) Conclusion: TyG-BMI is positively associated with BMD and geometry, and negatively associated with risk of fracture in nondiabetic middle-aged and elderly Chinese men and women.

Age Related Trends in Structural Indices of Proximal Femur in Women Aged 20-70 in Southern Sri Lanka

Age related trends of the indices of hip structure help understanding how bone strength changes with age and the increased bone fragility in old age. Community-dwelling women aged 20-70years (n = 419) were selected by stratified random method and divided into age categories; 20-29years (n-69), 30-39years (n = 60), 40-49years (n = 69), 50-59years (n = 107) and 60-70years (n = 114). All subjects underwent dual energy x-ray absorptiometry (DXA) and hip structure analysis using Hologic Discovery scanner (Hologic Inc, Bedford, USA). Measured indices included hip axis length (HAL) and neck shaft angle (NSA) of the proximal femur. Cross sectional area (CSA), cross sectional moment of inertia (CSMI), section modulus (SM), cortical thickness (CT), buckling ration (BR) of three regions of interest; narrow neck, intertrochanteric region and femoral shaft, were also measured. Age related trends of all indices were studied with Locally Weighted Scatterplot Smoothing lines (LOESS) and ANOVA. Mean HAL and NSA values were not different between age categories. CSA, CSMI, SM and CT in three different regions showed curvilinear relationships with age. These indices gradually increased with age between 20-50 years and the maximum values were seen in the 40-49years age category and they declined afterwards. The decline of these indices was more rapid in the narrow neck and intertrochanter regions when compared with femoral shaft and the lowest mean CSA, CSMI, SM and CT in these two regions were seen in the 60-70 age category. BR showed a gradual decrease with age between 20-50 years and the lowest mean value was seen in the 40-49 age category. BR increased afterwards and the maximum mean value was seen in the 60-70 age category. This study demonstrates the dynamics of structural properties of proximal femur in the three selected cross sections of community-dwelling women aged 20-70 years and the increased bone fragility in old age.

Higher BMI and lower femoral neck strength in males with type 2 diabetes mellitus and normal bone mineral density

BackgroundType 2 diabetes mellitus (T2DM) and osteoporosis are two age-associated diseases. Body mass index (BMI) is positively associated with osteoporosis or osteopenia in T2DM population. Bone mineral density does not necessarily reflect the alterations in bone microarchitecture. Our aims were to investigate the relationship between BMI and femoral neck strength in males with T2DM and normal range of bone mineral density (BMD). MethodsThis study enrolled 115 males (median age 53.3 years) with T2DM and normal BMD. Femoral neck strength indexes, including compression strength index (CSI), bending strength index (BSI), impact strength index (ISI), were calculated by parameters generated from Dual-energy X-ray absorptiometry software. Pearson correlation analysis was performed to evaluate the relationships between BMI and femoral neck strength variables. ResultsCompared with T2DM-normal weight group, T2DM-overweight group and T2DM-obesity group had a higher femur neck and total femur BMDs. Cross sectional moment of inertia (CSMI), cross sectional area (CSA), section modulus (SM) were significantly higher (all p<0.05), and buckling ratio (BR) (6.35±2.08 vs 7.18±1.71) was lower in T2DM-obesity group than in T2DM-normal weight group. Compared with T2DM-normal weight group, CSI (all p<0.001), BSI (all p<0.001), ISI (all p<0.001) were significantly reduced in T2DM-obesity and T2DM-overweight groups. Pearson correlation analysis indicated that BMI was negatively correlated with CSI (r= − 0.457, p<0.001), BSI(r = −0.397, p<0.001), ISI (r = − 0.414, p<0.001). ConclusionsHigher BMI is associated with lower femoral neck strength in males with T2DM and normal BMD. It implies that femoral neck fracture risk increases in obese and diabetic males, despite their high bone density.

Comparison of femoral neck geometric parameters between Chinese and Japanese females.

Femoral neck fracture is the most serious osteoporotic fractures that is responsible for high medical costs and high mortality. Femoral neck geometric parameters (FNGPs) are important parameters that reflect the geometrical characteristics of femoral neck, and are closely related to the strength of femoral neck and the risk of fragility fracture.There are differences in the incidence of femoral neck fractures among races. However, whether there is difference in FNGPs among races is unknown.Therefore, this study aims to compare the differences in FNGPs between Chinese and Japanese females. This study was a cross-sectional study, in which 3 859 healthy females aged 10-86 (45.7±17.1) years old were recruited from Changsha City of Hunan Province and surrounding areas. The weight and height were measured and recorded, and the body mass index (BMI) was calculated. A dual energy X-ray absorptiometry (DXA) bone densitometer was used to measure femoral neck projective bone area (BA) and bone mineral density (BMD). FNGPs were calculated using the BMD and BA, which included the outer diameter (OD), cross-sectional area (CSA), cortical thickness (CT), endocortical diameter (ED), buckling ratio (BR), section modulus (SM), cross-sectional moment of inertia (CSMI), and compression strength index (CSI). The data of FNGPs in Japanese females was collected from literature. These subjects were grouped by 10-year age. The mean and standard deviation of height, weight, BMI, femoral neck BMD, and FNGPs of each group were calculated. The model with the best goodness-of-fit was selected from various mathematical regression models to analyze the distribution trend and the best fitting curve of FNGPs with age. The differences in FNGPs between Chinese and Japanese females were analyzed by using age-corresponding mean fitting curve for paired t-test, and the relative change rates of FNGPs were compared. The mean values of FNGPs were significantly different among different years old healthy females (all P<0.01). The mean values of OD, CSA, CT, SM, and CSMI in femoral neck were high at 30 to 39 years old, and then they were gradually decreased with age. The CSI reached its peak at 20-29 years old, and it was decreased gradually after 30 years old. ED and BR were at a low level before 40 years old, they were gradually increased after 40 years old, and reached the maximum average value at 80-86 years old. The variations in FNGPs with age were fitted with the best goodness-of-fit by applying the cubic regression model and the determination coefficients of regression equations (R2: 0.062-0.404) were significant (all P<0.01). The distribution trend of FNGPs with age varied with the indices, among which CSA, CT, SM, CSMI and CSI were increased with age before 35 years old, and then they were decreased with age; BR was at a low level in the early stage, and then it was increased with age after about 40 years. There were significant differences in the fitting curves of FNGPs related to age between Chinese and Japanese females (all P<0.01). The fitting curves of OD, ED, BR and SM in Chinese females were significantly higher than those in Japanese females (all P<0.01), while those of CSA and CT in Chinese females were significantly lower than those in Japanese females (all P<0.01). Before the age of 50, the curves of CSMI and CSI of Chinese females were significantly higher than those of Japanese females (all P<0.01), while after the age of 60 the situation was reversed (all P<0.01). Except for SM and CSI, there were significant differences in the rate of OD, CSA, CT, ED, BR and CSMI with age (all P<0.01). By the age of 80 years old, the rates of change in OD, ED, and BR with the age in Chinese females were increased by 0.91%,3.94%, and 47.5%, respectively, while those in Japanese females were increased by 8.57%, 15.8% and 85.3%, respectively；the rates of change of CSA, CT, and CSMI with the age in Chinese females were declined 28.0%, 29.6%, and 25.2%, respectively, while those in Japanese females were declined 29.9%, 36.2%, and 10.9%, respectively. There were significant difference in the rates of change in FNGPs with the age between Chinese and Japanese females (all P<0.01). The study reveals the variation of FNGPs with age in Chinese, and confirms that there are racial differences in FNGPs between Chinese and Japanese females, which may be one of the important reasons for the difference in the incidence of femoral neck fracture between Chinese and Japanese females.

Packing a flexible fiber into a cavity.

The insertion of an elastic rod or fiber into a confining cavity is studied. Such an insertion is a feature of a variety of problems, including packing and unpacking of DNA in viral capsids and the insertion of catheters during surgery. We consider a simplified geometry in which the container is a smooth (frictionless) circular cylinder of radius a. The fiber is pushed through a hole in the curved surface of the cylinder and is then assumed to stay in a cross-sectional plane perpendicular to the cylinder axis. A solution is found for the fiber shape in which most of the fiber lies against the curved interior surface of the cylinder, apart from the final end sectionof the fiber, of length 2.0888a, which crosses the interior of the cylinder before ending at the opposite side, which it meets at an angle 1.15rad to the normal. The force required to push the fiber into the cylinder is EI/2a^{2}, where E is the fiber's Young's modulus and I its cross-sectional moment of inertia. The shape of the final end sectionof the fiber is confirmed by experiment.

Does hip structural analysis confer additional benefit to routine BMD assessment in postmenopausal women with hip fracture? A study from a tertiary center in southern India.

There is limited information with regard to comprehensive bone health in Indian postmenopausal women with neck of femur fracture. We studied the bone mineral density (BMD), trabecular bone score (TBS), proximal hip geometry, and bone mineral biochemistry in postmenopausal women with and without femoral neck fractures. This was a cross-sectional study conducted at a tertiary care center in South India. BMD, TBS, and hip structural analysis (HSA) were assessed using a dual-energy X-ray absorptiometry (DXA) scanner. Bone mineral biochemical profiles were also studied. A total of 90 postmenopausal women with acute femoral neck fracture with mean (SD) age of 63.2 (6.1) years and 90 age-matched controls were included. The prevalence of osteoporosis was higher among cases as compared to controls (83.3% vs 47.8%; P < 0.001). Degraded bone microarchitecture (TBS value < 1.200) was more frequent among women with hip fracture as compared to controls (46.7% vs 31.1%; P = 0.032). Cross-sectional moment of inertia (CSMI) was significantly lower at the narrow neck (NN) and inter-trochanteric (IT) region in cases (P < 0.05) and buckling ratio (BR) was significantly higher at all three sites in postmenopausal women with femoral neck fracture as compared controls. Multivariate logistic regression analysis showed that femoral neck osteoporosis, low CSMI at NN and high BR at NN and femoral shaft emerged as factors significantly associated with femoral neck fractures. This study highlights that impaired parameters of proximal hip geometry and a low trabecular bone score may be significantly associated with femoral neck fractures in postmenopausal women.