Probabilistic Fracture Research Articles

Plastic strain effect on cleavage microcracks propagation in probabalistic statement. Part 2. Research results

The second part of the paper presents the results of uniaxial tension testing of smooth round bars of 2Cr–Ni–Mo–V steel in the thermally-embrittled state and St3 steel in the initial state. SEM examination of the fracture surfaces is carried out. The brittle fracture probability is calculated using the Prometey model presented in the first part of this article. It has been found that the plastic strain effect on the microcrack propagation probability is caused by two reasons: (1) the critical brittle fracture stress increase due to formation of new barriers for microcrack under plastic deformation, and (2) the working volume decrease due to the neck formation in tensile round bar. A unified set of parameters has been proposed to take into account the plastic strain effect on cleavage microcracks propagation probability for WWER-1000 RPV steel and low-alloyed low-strength steel.

Low geriatric nutritional risk index is associated with osteoporosis and fracture risk in patients with chronic liver disease: a cross-sectional study

BackgroundPatients with chronic liver disease (CLD) frequently suffer from malnutrition and bone diseases, both of which heighten the risk of poor clinical outcomes. This study investigated the relationship between geriatric nutritional risk index (GNRI) and osteoporosis or fracture risk using the fracture risk assessment tool (FRAX) in patients with CLD.MethodsThis cross-sectional study included 209 consecutive patients with CLD. The participants were divided into two groups: the all-risk group (GNRI ≤ 98.0) with nutrition-related risk and the no-risk group (GNRI > 98.0) without nutrition-related risk. Osteoporosis was diagnosed according to the World Health Organization criteria. The FRAX was used to estimate the 10-year probabilities of hip fracture (FRAX-HF) and major osteoporotic fracture (FRAX-MOF).ResultsOf the 209 patients, 72 (34.4%) had osteoporosis. The all-risk group had a significantly higher prevalence of osteoporosis than the no-risk group (p < 0.001). Conversely, patients with osteoporosis had significantly lower GNRI than those without osteoporosis (p < 0.001). Multivariate analysis found lower GNRI to be a significant and independent risk factor for osteoporosis (odds ratio [OR], 0.927; p < 0.001) and high fracture risk derived from FRAX (without BMD) (OR, 0.904; p = 0.009). GNRI had a positive correlation with bone mineral density (BMD) at the lumbar spine, femoral neck, and total hip, but a negative correlation with FRAX-HF and FRAX-MOF in the FRAX with and without BMD (p < 0.001 for all). The cutoff value of GNRI for predicting osteoporosis was 104.9, with sensitivity of 0.667 and specificity of 0.657.ConclusionsThe GNRI was significantly associated with osteoporosis and FRAX-derived fracture risk in patients with CLD, suggesting that it could be a simple and useful indicator for the management of bone diseases.

Clinical and demographic factors determining patient fracture risk decision point (FRDP): The improving risk communication in osteoporosis (RICO) project.

This part of the Improving Risk Communication in Osteoporosis (RICO) study aims to understand patients' willingness to initiate osteoporosis treatment given a hypothetical fracture probability-derived from the FRAX® Risk Assessment Tool-and how age, fracture history, and numeric literacy may influence this. In 2022-2023, 332 postmenopausal women at risk of fracture were interviewed from nine countries to determine participants' Fracture Risk Decision Point (FRDP), the lowest probability of major osteoporotic fracture at which they would accept an osteoporosis medication. Participants' FRDP was evaluated given eight hypothetical 10-year FRAX scores. In countries with FRAX-based treatment thresholds, over half of the participants per country reported an FRDP that was below the threshold. Collectively, 79.2% demonstrated FRDPs at or below their respective threshold. Age and fracture history did not have a strong influence on FRDP; however, those who demonstrated higher levels of numeric literacy reported a significantly higher median FRDP (10%) compared to those who showed lower levels (5%, p < 0.001). Most patients were willing to accept an osteoporosis medication prescription at a hypothetical FRAX probability that was even lower than that of their nationally recommended treatment threshold. Literacy scores had a significant influence on FRDP whereas age and fracture history did not.

Cost-effectiveness intervention thresholds for romosozumab and teriparatide in the treatment of osteoporosis in the UK.

To estimate the 10-year probability of a major osteoporotic fracture (MOF) at which sequential treatment with romosozumab or teriparatide followed by alendronate, compared with alendronate alone, becomes cost-effective in a UK setting. A microsimulation model with a Markov structure was used to simulate fractures, costs, and quality-adjusted life years (QALYs), in women receiving sequential treatment with either romosozumab or teriparatide followed by alendronate, compared with alendronate alone. Patients aged 50 to 90years with a recent MOF, hip or spine fracture were followed from the start of a 5-year treatment until the age of 100years or death. The analysis had a healthcare perspective. Efficacy of romosozumab, teriparatide and alendronate was derived from phase III randomised controlled trials. Resource use and unit costs were derived from the literature. Cost-effectiveness intervention threshold (CEIT), defined as the 10-year probability of a major osteoporotic fracture at which treatment becomes cost-effective, was compared with clinically appropriate intervention thresholds for bone-forming treatment in women with very high fracture risk as recommended by the UK National Osteoporosis Guideline Group (NOGG). The base case analysis showed that sequential romosozumab-to-alendronate treatment was cost-effective from a 10-year MOF probability of 18-35% and above depending on age and site of sentinel fracture at a willingness to pay (WTP) of £30,000. For teriparatide-to-alendronate, treatment was cost-effective at a 10-year MOF probability of 27-57%. The results were sensitive to pricing of the drugs but relatively insensitive to treatment duration, romosozumab persistence assumptions, and site of sentinel fracture. The CEITs for romosozumab-to-alendronate treatment were lower than the clinical thresholds from the age of 70years meaning that treatment could be considered both cost-effective and aligned with the NOGG treatment guidelines. By contrast, for teriparatide-to-alendronate the CEITs were higher than the clinical thresholds irrespective of age. However, cost-effective scenarios were found in the presence of strong clinical risk factors in addition to a recent sentinel fracture. The results of this study indicate that sequential romosozumab-to-alendronate or teriparatide-to-alendronate treatment can be a cost-effective treatment option for postmenopausal women at very high risk of fracture.

Grain Microstructure in Friction-Stir-Welded Dissimilar Al/Mg Joints of Thin Sheets with/without Ultrasonic Vibration.

Electron backscattered diffraction (EBSD) characterization was conducted on the typical regions in friction-stir-welded dissimilar Al/Mg joints of 2 mm thick sheets with/without ultrasonic assistance. The effects of ultrasonic vibration (UV) on the grain size, recrystallization mechanisms, and degree of recrystallization on both sides of the Al-Mg bonding interface and the intermetallic compounds (IMCs) were investigated. It was found that on the Mg side of the weld nugget zone (WNZ), the primary dynamic recrystallization (DRX) mechanisms were discontinuous dynamic recrystallization (DDRX) and continuous dynamic recrystallization (CDRX), with geometric dynamic recrystallization (GDRX) playing a secondary role. On the Al side of the WNZ, CDRX was identified as the primary mechanism, with GDRX as a secondary contributor. While UV did not significantly alter the DRX mechanisms in either alloy within the WNZ, it promoted the aggregation and rearrangement of dislocations. This led to an increase in high-angle grain boundaries (HAGBs) and an enhanced degree of recrystallization in the welds. The average grain size in both the Al and Mg alloys of the WNZ followed a pattern of initially increasing and then decreasing along the thickness direction, reaching a maximum in the upper-middle part and a minimum at the bottom. The influence of UV on the average grain size in the WNZ was minimal, with only slight grain refinement observed, and the minimum refinement degree was only 0.9%. The Schmid factor (SF) on the WNZ and thermo-mechanically affected zone (TMAZ) boundary regions of the advancing side (AS) indicates that the application of UV increased the likelihood of basal slip and extension twinning in the crystal structure. In addition, UV reduced the thickness of IMCs and improved the strength of the Al-Mg bonding interface. These results suggest a higher probability of fracture along the TMAZ and WNZ boundary on the AS when UV was applied.

Fracture Risk Prediction Using the Fracture Risk Assessment Tool in Individuals With Cancer

The Fracture Risk Assessment Tool (FRAX) is a fracture risk prediction tool for 10-year probability of major osteoporotic fracture (MOF) and hip fracture in the general population. Whether FRAX is useful in individuals with cancer is uncertain. To determine the performance of FRAX for predicting incident fractures in individuals with cancer. This retrospective population-based cohort study included residents of Manitoba, Canada, with and without cancer diagnoses from 1987 to 2014. Diagnoses were identified through the Manitoba Cancer Registry. Incident fractures to March 31, 2021, were identified in population-based health care data. Data analysis occurred between January and March 2023. FRAX scores were computed for those with bone mineral density (BMD) results that were recorded in the Manitoba BMD Registry. This study included 9877 individuals with cancer (mean [SD] age, 67.1 [11.2] years; 8693 [88.0%] female) and 45 877 individuals in the noncancer cohort (mean [SD] age, 66.2 [10.2] years; 41 656 [90.8%] female). Compared to individuals without cancer, those with cancer had higher rates of incident MOF (14.5 vs 12.9 per 1000 person-years; P < .001) and hip fracture (4.2 vs 3.5 per 1000 person-years; P = .002). In the cancer cohort, FRAX with BMD results were associated with incident MOF (HR per SD increase, 1.84 [95% CI, 1.74-1.95]) and hip fracture (HR per SD increase, 3.61 [95% CI, 3.13-4.15]). In the cancer cohort, calibration slopes for FRAX with BMD were 1.03 for MOFs and 0.97 for hip fractures. In this retrospective cohort study, FRAX with BMD showed good stratification and calibration for predicting incident fractures in patients with cancer. These results suggest that FRAX with BMD can be a reliable tool for predicting incident fractures in individuals with cancer.

Prevalence of vertebral fractures and associated factors in thai diabetic postmenopausal women

T2DM (Type 2 Diabetes Mellitus) patients with vertebral fractures have a higher mortality rate than non-DM (nondiabetic patients). However, the prevalence of vertebral fractures in the Asian diabetic population is not well established. Moreover, despite an apparent increase in fracture risk in patients with diabetes, Asian countries have provided contradictory data demonstrating that bone mineral density (BMD) varies significantly in T2DM patients. The aim of this study was to examine and compare the prevalence of vertebral fractures and osteoporosis, as well as BMD and the FRAX score, between individuals with and without T2DM and assess the association of these factors with vertebral fractures. Postmenopausal Thai women attending diabetic and health check-up clinics were recruited. BMD at the lumbar spine, total hip, and femoral neck was measured via dual-energy X-ray absorptiometry. A morphometric vertebral fracture (VF) was defined by a lateral thoracolumbar (T-L) X-ray radiograph. The Fracture Risk Assessment Tool (FRAX) was used to calculate the 10-year probabilities of hip and major osteoporotic fracture (MOF), which were calculated on the basis of the Thai FRAX model. A total of 435 participants were recruited, including 145 postmenopausal women with T2DM and 290 non-DM individuals. T2DM patients had a significantly greater BMI (p = 0.006) and BMD at the femoral neck (p = 0.024) and total hip (p = 0.017), but there was no significant difference in the FRAX score, including the 10-year probability of hip fracture or MOF, either with or without BMD, between individuals with and without T2DM. The prevalence of osteoporosis in non-DM women was significantly higher at the femoral neck (OR = 0.56, 95% CI: 0.34 to 0.93, p = 0.029) but comparable at the lumbar spine. Individuals with T2DM had a significantly higher rate of vertebral fractures, particularly those involving two or more levels, than those without T2DM. Diabetes was significantly associated with \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\:\\ge\\:$$\\end{document}2 VF (OR = 3.83, 95% CI: 1.77 to 8.28, p = 0.001), and the association remained unchanged after controlling for other clinical factors (adjusted OR = 3.72, 95% CI 1.70–8.15; p = 0.001). Our study demonstrated a greater prevalence of multiple (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\:\\ge\\:$$\\end{document} two levels) VFs in women with T2DM than in non-DM controls.

Fracture strength analysis of large-size and thin photovoltaic monocrystalline silicon wafers

Diamond wire slicing technology is the main method to manufacture the substrate of the monocrystalline silicon-based solar cells. With the development of technology, the size and thickness of monocrystalline silicon wafer are respectively getting larger and thinner, which cause an increase in silicon wafer fracture probability during wafer processing and post-processing. And the change of the sawing speed, saw wire diameter and abrasive size also affect the wafer’s surface characteristics, thereby affect its fracture strength. In this paper, monocrystalline silicon wafer with large size of 210 mm × 210 mm was taken as the research object, 4-point bending test was carried out on each series of silicon wafers. The load–displacement curves during bending test were collected, and the fracture stress values were calculated by finite element method. The characteristic fracture strength and Weibull modulus of each series of silicon wafers were obtained through the statistical analysis of the data using Weibull distribution function. The effect of the silicon wafer thickness, the position of the silicon wafer in the silicon brick (usage time of the saw wire varies), and the bending test direction on the fracture characteristics was analyzed. The results showed that the increase of thickness increase the characteristic fracture strength of silicon wafer. The characteristic fracture strength of the front wafers (sawn by the fresh wire) is the smallest, while the characteristic fracture strength of the middle wafers and the rear wafers (sawn by the worn wire) are similar. The characteristic fracture strength of bending in the direction of perpendicular to the saw marks is 2–3 times that of bending in the direction of parallel to the saw marks. The reason of the difference of characteristic fracture strength was analyzed based on the surface morphology, roughness, and the saw marks of silicon wafer. In this paper, the fracture characteristics of large size monocrystalline silicon wafer are studied to provide fracture data support for industry production. The mechanism and main effect factors of silicon wafer fracture are revealed, which provides directions for improving the sawing quality and reducing the fracture probability during wafer production process and post-processing.

Incongruent Treatment Recommendations Between Left and Right Hip Bone Mineral Densities.

Objective The official position of the International Society for Clinical Densitometry (ISCD) is that either hip site can be scanned with dual-energy X-ray absorptiometry (DXA) imaging. Whether there is a difference in guideline-based treatment recommendations between hip sites has not previously been assessed. Methods We conducted a retrospective analysis of all individuals who underwent DXA imaging at a single center from September 1, 2018, to October 31, 2019. Women aged ≥ 40 years old and men aged ≥ 50 years old were included. Individuals without bilateral hip measurements or who were on osteoporosis treatment were excluded. The 10-year probability of fracture using the fracture risk assessment tool (FRAX) was calculated for each hip when the worst T-score was in the osteopenia range. Results Of the included participants, 10% (n = 151/1505) had incongruent treatment recommendations (ITR) between the left and right hips. In the ITR group, 70% (n = 106) had osteopenia and 30% (n = 45) had osteoporosis. Age was the only significant risk factor for ITR overall (OR: 1.06, 95% CI: 1.04-1.09). In the osteopenia group, however, age (OR: 1.17, 95% CI: 1.13-1.21), history of parental hip fracture (OR: 3.16, 95% CI: 1.65-6.05), and glucocorticoid use (OR: 4.18, 95% CI: 1.6-11.0) were associated with ITR. In the osteoporosis group, the right hip (femoral neck and total) T-scores were significantly lower compared to the left. Conclusion Measuring bone mineral density on both hips changes treatment recommendations in 10% of people. This was more likely in those with osteopenia who were older, had a parental history of hip fracture, or were on glucocorticoids.Measuring both hips did not add time or cost to patient care. Given the minimal disadvantages to measuring both hips, there should be a strong consideration to change the current guidance of only measuring one hip.

Association between trabecular bone score, 10-year probability risk for fracture, and vertebral fractures in rheumatoid arthritis

ObjectivesThe aim was to assess the association and predictive value of trabecular bone score (TBS), fracture risk assessment tool (FRAX), and TBS-adjusted FRAX with prevalent vertebral fractures (VFs) in patients with rheumatoid arthritis (RA). MethodsPatients diagnosed with RA were included in this cross-sectional study. Clinical data and laboratory tests were collected on the same day as the dual-energy x-ray absorptiometry (DXA) scan. TBS, bone mineral density (BMD), and vertebral fracture assessment (VFA) were obtained from the DXA scan. We used the FRAX tool to assess the 10-year probability of major osteoporotic fracture (MOF-FRAX) and hip fracture (HF-FRAX) with and without BMD. These parameters were further adjusted for TBS. Patients with prevalent VFs were defined as those with moderate to severe VFs from T4 to L4. VFs presence was used as the binary variable in the logistic regressions and receiving operator characteristics (ROC) curves analysis. ResultsSixty-nine patients were enrolled, with 55.1 % being postmenopausal. The mean TBS was 1.328 ± 0.104. Osteoporosis according to the WHO criteria was present in 39 patients (56.5 %), and six patients (8.7 %) had VFs with thoracic predominance (66.67 %). Univariate and multivariate logistic regression analyses did not show an association between TBS and vertebral fractures, but FRAX scores indicated such an association. The area under the curve (AUC) with 95 % confidence intervals (CI) for the MOF-FRAX score with BMD, MOF-FRAX score without BMD, TBS-adjusted MOF-FRAX score, and TBS were 0.837 [0.686–0.988], 0.795 [0.629–0.961], 0.778 [0.571–0.984], and 0.515 [0.298–0.731], respectively. ConclusionIn our RA patients, FRAX scores were associated with vertebral fractures (VFs), while TBS was not. The MOF-FRAX score combined with BMD, showed the best AUC for VFs in this population.

Computed tomography-derived structural analysis for the likelihood of pathologic fracture in canine antebrachial osteosarcoma.

Determining the risk of pathologic fracture in dogs with a primary bone tumor would aid in case selection for in-situ treatment options. Prior research found strong relationships between in vitro strength of canine antebrachii with primary bone tumors and CT-derived metrics. This study assesses the prognosis for pathologic fracture in dogs with distal radial bone tumors using CT-derived structural analysis metrics. CT images of the antebrachium in dogs with aggressive osseous lesions of the radius were used to calculate structural rigidity and failure forces, including axial rigidity (AR), craniocaudal bending rigidity (BR), torsional rigidity (TR), and failure forces for a slightly-curved/asymmetric beam (Fs) or a curved beam (Fc). Metrics were compared with the clinical outcome of radial fracture. Eight of 19 dogs with CT-derived metrics developed a radial fracture. The prognostic potential of the metrics to discriminate fractured and nonfractured bones was analyzed using receiver operating characteristic curves (area under the curve), stepwise logistic regression, and classification regression (CART) analyses. Fc was the most sensitive and specific metric for prognosing fracture occurrence (AUC=0.864). When dog body weight (BW) was included, all five metrics had AUC>0.705. Fc was the best predictor of fracture using stepwise logistic regression and CART analysis, followed by BR. An indication of fracture probability can be determined by normalizing Fc or BR with dog BW or by using the logistic regression equation of either metric with dog BW. Results warrant further analysis of a larger cohort to evaluate fracture likelihood in dogs with antebrachial bone neoplasia.

Age-associated risk of sarcopenia, falls and fractures: results of Ukrainian cohort study

Background. It is well-known that sarcopenia increases the risk of falls and fractures, and therefore, requires correction to improve the quality of life of elderly people. This research purposed to study the age-related changes in the sarcopenia risk, falls, and fractures in Ukrainian women in the late reproductive and postmenopausal periods. Materials and methods. We examined 573 females aged from 40 to 89 years old. The subjects were grouped by age decades and presence of high sarcopenia risk (HSR). The SARC-F questionnaire measured the sarcopenia risk, and the risk of falls using the Desmond Fall Risk Questionnaire, the 10-year probability of major osteoporotic and hip fractures was assessed by FRAX, and daily activity — according to the IADL scale. Also, we performed the hand grip strength and five-repetition sit-to-stand tests. Results. The frequency of HSR increased with age from 1.5 % in the 40–49-year-old group to 73.7 % in subjects over 80, as well as fracture and fall risks (p &lt; 0.00001 for both indices) related to decreasing independence in the subject’s everyday life. Also, we revealed age-dependent loss of muscle strength according to the hand grip and the five-repetition sit-to-stand tests. After the adjustment of the subjects by age we found that the females with HSR had a higher risk of falls, a lower level of independence, and increased frequency and risk of osteoporotic fractures. Conclusions. Women with HSR have a higher risk of falls, fractures, and more limitations in daily living activities independently from age and body mass index. These findings request comprehensive management of older women with attention to various parameters for the increase of independence and quality of life.

Effects of a Multifactorial Program with Case Management for Falls Prevention on Functional Outcomes in Community-Dwelling Older People: A Randomized Clinical Study.

To evaluate the effects of a multifactorial fall prevention program based on CM on physical performance, the presence of pain, and the risk of falls and fractures in older people who have suffered falls. This randomized, single-blind clinical trial with parallel groups, Intervention Group (IG) and Control Group (CG), was composed of 55 older people with a history of falling, living in the community. All participants underwent an initial assessment via video call (containing anamnesis, timed up-and-go test, falls risk score, short physical performance battery, and clinical frax). The IG underwent CM, the physical exercise protocol, and the cognitive stimulation protocol. The CG was monitored through telephone calls and received general health and fall guidance. No significant results were found in the physical capacity, the presence of pain, the risk of falls, or the fractures between the Intervention and Control Groups and between assessments. This program was not effective in improving functional performance, but it was important for characterizing pain and the probability of fracture in the next 10 years in this population.

A new device and calibration method for the fracture energy testing of single-particle impact

This study presents a piezoelectric fast load cell (PFLC) as a novel device for testing single particle fracture energy under impact and proposes a collision model for measurement and calibration. The research examined various models, modifying the long-rod model to create a more practical short-rod model describing the contact dynamics during collision processes. Through back-calculating the Young's modulus of glass beads, the optimized measurement settings are calibrated for practical use based on the short-rod model, which is corroborated by comparison with fracture probabilities obtained from the drop weight tests and PFLC. It was verified that the observed fracture characteristics of ore align with established principles of fracture mechanics, validating the testing approach. The PFLC offers a cost-effective and compact substitute to classic ultra-fast load cell (UFLC), potentially enhancing the adoption of advanced comminution models like the Tavares Model.

Characterization of combined blast- and fragments-induced synergetic damage in polyurea coated liquid-filled container

Liquid-filled containers (LFC) are widely used to store and transport petroleum, chemical reagents, and other resources. As an important target of military strikes and terrorist bombings, LFC are vulnerable to blast waves and fragments. To explore the protective effect of polyurea elastomer on LFC, the damage characteristics of polyurea coated liquid-filled container (PLFC) under the combined loading of blast shock wave and fragments were studied experimentally. The microstructure of the polyurea layer was observed by scanning electron microscopy, and the fracture and self-healing phenomena were analyzed. The simulation approach was used to explain the combined blast- and fragments-induced on the PLFC in detail. Finally, the effects of shock wave and fragment alone and in combination on the damage of PLFC were comprehensively compared. Results showed that the polyurea reduces the perforation rate of the fragment to the LFC, and the self-healing phenomenon could also reduce the liquid loss rate inside the container. The polyurea reduces the degree of depression in the center of the LFC, resulting in a decrease in the distance between adjacent fragments penetrating the LFC, and an increase in the probability of transfixion and fracture between holes. Under the close-in blast, the detonation shock wave reached the LFC before the fragment. Polyurea does not all have an enhanced effect on the protection of LFC. The presence of internal water enhances the anti-blast performance of the container, and the hydrodynamic ram (HRAM) formed by the fragment impacting the water aggravated the plastic deformation of the container. The combined action has an enhancement effect on the deformation of the LFC. The depth of the container depression was 27% higher than that of the blast shock wave alone; thus, it cannot be simply summarized as linear superposition.

Association of Midnight Cortisol Level with Bone Mineral Density in Chinese Patients with Type 2 Diabetes Mellitus: A Cross-Sectional Study.

To investigate the association of the midnight cortisol level with bone mineral density (BMD) in patients with type 2 diabetes mellitus (T2DM). This study included 249 T2DM patients (148 males with an average age of 53.8 years and 101 postmenopausal females with an average age of 63.6 years) admitted to Xiamen Hospital of Zhongshan Hospital Affiliated to Fudan University from January 2018 to April 2020. Baseline data were compared between patients with normal BMD and those with osteoporosis/osteopenia. The patients also were divided into groups according to the tertiles of midnight cortisol levels. Among all T2DM, 178 had osteoporosis/osteopenia, including 98 men and 80 women. The baseline data analysis showed that patients with osteoporosis/osteopenia were more likely to be older, female, and thin, and to have high cortisol. Additionally, elevated estradiol levels had a protective effect on bone; once osteoporosis/osteopenia occurred, the probability of severe osteoporotic fracture was significantly increased. The BMD of the femoral neck, hip joint and lumbar spine decreased with increasing midnight cortisol level in men, postmenopausal women, and all T2DM patients (P<0.05). Multivariate logistic regression analysis identified body mass index, estradiol level, and midnight cortisol level as independent risk factors for osteoporosis/osteopenia in T2DM patients. Higher midnight cortisol levels are significantly associated with increased risk of osteoporosis/osteopenia in T2DM patients. Thus, the midnight cortisol level represents a valuable marker for assessing osteoporosis/osteopenia risk in these patients.

Study on the influence of vertical stress difference coefficient on fracture characteristics of shale under high stress

AbstractTo study the effect of vertical stress difference coefficient on fracture characteristics of shale fracturing, high stress true triaxial hydraulic fracturing test was carried out. By analyzing the profile after fracturing, it was found that the area of hydraulic fracture increased with the increase of vertical stress difference coefficient, and the probability of shear fracture will increase when the stress difference coefficient was high. A high vertical stress differential coefficient exerts a strong control over the direction of crack propagation, while a low vertical stress difference coefficient is beneficial to improve the roughness of hydraulic fracture surface and promote the formation of complex fracture network. By analyzing the pump pressure curves of different tests, it was found that with the increase of vertical stress difference coefficient, the formation and expansion of hydraulic fractures were more difficult. The surface characteristics of hydraulic fractures were quantified based on three‐dimensional topography scanning technology, combined with fractal dimension and fracture area calculation method, the results showed that with the increase of vertical stress difference coefficient, the fractal dimension and fracture area decreased. Since shale is stratified, and the transformation of reservoir is mainly reflected in the enhancement of fracture complexity through tensile failure, Xsite discrete grid method was used to study the influence of fracture propagation behavior with different bedding strengths. The results showed that when the bedding tensile strength was high, hydraulic fractures were easy to pass through the bedding, and when the bedding tensile strength was low, hydraulic fractures were easy to be captured by natural fractures. In addition, tensile cracks were easy to form when the tensile strength of bedding was low, shear cracks were easy to form when the strength of bedding was high, and the fracture volume was larger when the strength of bedding was low. This study provides a theoretical basis for hydraulic fracturing in engineering.

The relationship of body composition with bone mineral density and 10-year probability of hip fracture in postmenopausal women

IntroductionPostmenopausal osteoporosis and fractures are widely prevalent. However, the relationship of body composition with bone health in this population remains unclear. The aim of this study was to investigate the association of body composition with bone mineral density (BMD) and 10-year probability of hip fracture in postmenopausal women. Materials and MethodsThis is a cross-sectional study. A total of 1285 subjects were included in our study. Body composition and BMD were assessed using dual-energy X-ray densitometry. The 10-year probability of hip fracture of participants was calculated. All participants were categorized into four groups: sarcopenic-obese (SO) group, sarcopenic-nonobese (S) group, nonsarcopenic-obese (O) group, or nonsarcopenic-nonobese control (C) group. Multivariate analyses and binary logistic regression were conducted to explore the relationship of body composition with BMD and 10-year probability of hip fracture. ResultsParticipants in S group were 2.8, 4.7 and 4.8 times more likely to develop osteoporosis in the lumbar spine, the total hip and femoral neck sites, respectively. Lean mass was positively correlated with BMD, wherein lumbar spine BMD was significantly affected by appendicular lean mass, while total hip BMD and femoral neck BMD were mainly influenced by trunk lean mass. Total fat mass was positively associated with total hip and femoral neck BMD, but not with lumbar spine BMD. A significant correlation was observed between lean mass and 10-year probability of hip fracture. ConclusionChanges in body composition in postmenopausal women could affect bone health. A decrease in regional lean mass may be associated with an increased risk of osteoporosis and fractures.

Performance of the Brazilian Fracture Assessment Risk Tool (FRAX) model and the age-dependent intervention thresholds according to National Osteoporosis Guideline Group (NOGG) guidelines on fracture prediction in community-dwelling older adults: the São Paulo Ageing and Health (SPAH) Study.

To determine the performances of FRAX and age-dependent intervention thresholds according to National Osteoporosis Guideline Group (NOGG) guidelines with and without bone mineral density (BMD) regarding fracture prediction in community-dwelling elderly Brazilians. Seven hundred and five older adults (447 women; 258 men) were followed for 4.3 ± 0.8years. FRAX risk for hip and major osteoporotic fractures with and without BMD was calculated at baseline. The bivariate analysis investigated the associations between the absolute probability of fracture (FRAX), as well as the age-dependent intervention thresholds (NOGG), and the incidence of vertebral fracture (VF), non-vertebral fracture (NVF), and major osteoporotic fractures (MOF), segregated by sex. Age-adjusted Poisson's multiple regression and ROC curves were constructed to determine FRAX and NOGG's accuracies as fracture predictors. Fractures occurred in 22% of women and 15% of men. FRAX with and without BMD was higher in women with all types of fractures (p < 0.001). Only NOGG risk classification without BMD was associated with NVF (p = 0.047) and MOF (p = 0.024). FRAX was associated with NVF in the multiple regression, regardless of BMD. ROC curves of FRAX with and without BMD had AUCs of 0.74, 0.64, and 0.61 for NVF, VF, and MOF, respectively. The most accurate risk cutoffs for FRAX were 8% for MOF and 3% for hip fractures. No statistically significant associations were found in men. FRAX predicted NVF more accurately than VF or MOF in elderlies, regardless of BMD. These results reiterate that FRAX may be used without BMD, even considering that Brazilian elderlies have known higher fracture risk.

Prevalence of HIV-associated osteoporosis and fracture risk in midlife women: a cross-sectional study in Zimbabwe.

Antiretroviral therapy roll-out has dramatically reduced HIV-related mortality; more women are living to reach menopause. Menopausal estrogen loss causes bone loss, as does HIV and some of its treatments. However, data describing HIV's impact on osteoporosis prevalence and fracture risk are scarce in southern Africa. A cross-sectional study of women aged 40-60years (49% women with HIV [WLH]) was conducted in Harare, Zimbabwe. Menopause, fracture, and HIV history were collected, and anthropometry and BMD (by DXA) measured, and FRAX 10-year fracture probabilities quantified. The FRAX probability of a major osteoporotic fracture (MOF) included HIV as a risk factor for secondary osteoporosis. Linear and Poisson regression determined the relationships between clinical risk factors and both femoral neck (FN) BMD and the 10-year FRAX probability of MOF respectively. The 393 participants had a mean (SD) age of 49.6 (5.8) years and mean (SD) BMI of 29.1 (6.0) kg/m2. 95% of WLH were antiretroviral therapy (ART) established (85% tenofovir disoproxil fumarate) and 81% had a viral load <50 copies/mL. A BMD T-score ≤ -2.5 was more common in WLH than those without, at both FN and lumbar spine (LS) (FN, 22 [11.4%] vs 5 [2.5%]; LS, 40 [20.8%] vs 9 [4.5%], respectively). Prior fracture was more prevalent in WLH: any fracture type (27 [14%] vs 14 [7%]); MOF (14 [7.3%] vs 5 [2.5%]). WLH had a higher 10-year MOF probability (median, 1.2%; IQR, 0.9-1.8) compared with those without HIV (1.0%; IQR, 0.9-1.5) (p < .001), although probabilities were low. Older age, low weight, and HIV infection were strongly associated with lower FN BMD. Higher probability of MOF was associated with older age, HIV infection, parental hip fracture and prior fracture, although adjustment attenuated the association with HIV. No woman reported anti-osteoporosis medication use. While osteoporosis and previous fractures were common and untreated in this relatively young population, particularly in WLH, the FRAX-predicted 10-year MOF risk was low. Clinical risk factors considered in fracture risk prediction tools in Zimbabwe may need contextual modification.