Probabilistic Fracture Research Articles

External validation of FRISBEE 5-year fracture prediction models: a registry-based cohort study.

Five-year risk prediction models for all fractures, major osteoporotic fractures (MOFs) and central fractures (proximal to forearm and ankle) from the FRISBEE cohort demonstrated good performance in the original derivation cohort. Our aim was to externally validate the FRISBEE-based 5-year prediction models in routine practice. Using the population-based Manitoba Bone Mineral Density (BMD) registry, we identified women aged 60-85years undergoing baseline BMD assessment from September 1, 2012 to March 31, 2018. Five-year probabilities of all fractures, MOFs and central fractures were calculated using the FRISBEE prediction models. We identified incident non-traumatic fractures up to 5years from population-based healthcare data sources. Performance characteristics included area under the receiver operating characteristic curve (AUROC), gradient of risk (hazard ratio [HR] per SD increase and across risk tertiles) from Cox regression analysis, and calibration (ratio 5-year observed cumulative incidence to predicted fracture probability). We included 9716 women (mean age 70.7 + / - SD 5.3years). During a mean observation time of 2.5years, all fractures, MOFs and central fractures were identified in 377 (3.9%), 264 (2.7%) and 259 (2.7%) of the women. AUROC showed significant fracture risk stratification with the FRISBEE models (all fractures 0.69 [95%CI 0.67-0.72], MOFs 0.71 [95%CI 0.68-0.74], central fractures 0.72 [95%CI 0.69-0.75]). There was a strong gradient of risk for predicting fracture outcomes per SD increase (HRs from 1.98 to 2.26) and across risk tertiles (HRs for middle vs lowest from 2.25 to 2.41, HRs for highest vs lowest from 4.70 to 6.50). However, risk was overestimated for all fractures (calibration-in-the-large 0.63, calibration slope 0.63), MOF (calibration-in-the-large 0.51, calibration slope 0.57) and central fractures (calibration-in-the-large 0.55, calibration slope 0.60). FRISBEE 5-year prediction models were externally validated to stratify fracture risk similar to the derivation cohort, but would need recalibration for Canada as risk was overestimated.

Using the Monte-Carlo Method with Subsequent Approximation in Statistical-Mechanical Modeling for Estimating the Reliability of NPP Pipelines and Pressure Vessels

For a large number of safety-critical components at existing and newly designed NPPs, the task of confirming their reliability by conventional statistical methods does not seem to be possible in view of both short periods of time for which these components have been in operation and almost no failures that have occurred for this period of time, as well as lack of analogs from the worldwide practices. One of approaches to assessing the failure probabilities of highly reliable reactor plant equipment involves application of the statistical-mechanical modeling method. For solving statistical-mechanical models, the Monte Carlo (MC) method, which has a number of advantages over analytical ones, is commonly used. However, the need to perform an excessively large number of statistical simulations in substantiating low event probabilities prompts specialists to search for alternative calculation methods. One of these techniques, proposed in this article, is a two-stage method that combines the Monte Carlo method and approximation of statistical data – the Monte Carlo method with subsequent approximation. Matters of reliability assessment with using statistical-mechanical modeling of components’ limit states are considered. The use of the proposed Monte Carlo method with subsequent approximation makes it possible to reduce the number of statistical simulations while preserving the accuracy of the results. This statement has been confirmed by a number of examples of calculating the probabilities of leaks and ductile-brittle fracture of reactor plant components.

Fluctuation-based fracture mechanics of heterogeneous materials.

We present results of a hybrid analytical-simulation investigation of the fracture resistance of heterogeneous materials. We show that bond-energy fluctuations sampled by Monte Carlo simulations in the semigrand canonical ensemble provide a means to rationalize the complexity of heterogeneous fracture processes, encompassing probability and percolation theories of fracture. For a number of random and textured model materials, we derive upper and lower bounds of fracture resistance and link bond fracture fluctuations to statistical descriptors of heterogeneity, such as two-point correlation functions, to identify the origin of toughening mechanisms. This includes a shift from short- to long-range interactions of bond fracture processes in random systems to the transition from critical to subcritical bond fracture percolation in textured materials and the activation of toughness reserves at compliant interfaces. Induced by elastic mismatch, they connect to a number of disparate experimental observations, including toughening of brittle solids by deformable polymers or organics in, e.g., gas shale, nacre; stress-induced transformational toughening in ceramics; and toughening of sparse elastic networks in hydrogels, to name a few.

Characterization of the highly fractured zone at the Grimsel Test Site based on hydraulic tomography

Abstract. In this study, we infer the structural and hydraulic properties of the highly fractured zone at the Grimsel Test Site in Switzerland using a stochastic inversion method. The fractured rock is modeled directly as a discrete fracture network (DFN) within an impermeable rock matrix. Cross-hole transient pressure signals recorded from constant-rate injection tests at different intervals provide the basis for the (herein presented) first field application of the inversion. The experimental setup is realized by a multi-packer system. The geological mapping of the structures intercepted by boreholes as well as data from previous studies that were undertaken as part of the In Situ Stimulation and Circulation (ISC) experiments facilitate the setup of the site-dependent conceptual and forward model. The inversion results show that two preferential flow paths between the two boreholes can be distinguished: one is dominated by fractures with large hydraulic apertures, whereas the other path consists mainly of fractures with a smaller aperture. The probability of fractures linking both flow paths increases the closer we get to the second injection borehole. These results are in accordance with the findings of other studies conducted at the site during the ISC measurement campaign and add new insights into the highly fractured zone at this prominent study site.

An assessment of intervention thresholds for high fracture risk in Chile.

The aim of the present study was to explore treatment paths and characteristics of women eligible for treatment in Chile based on major osteoporotic fracture (MOF) probabilities derived from FRAX®. Intervention and assessment thresholds were derived using methods adopted by the National Osteoporosis Guideline Group for FRAX-based guidelines in the UK but based on the epidemiology of fracture and death in Chile. Age-dependent and hybrid assessment and intervention thresholds were applied to 1998 women and 1122 men age 50years or more drawn from participants in the National Health Survey 2016-2017. Approximately 12% of men and women had a prior fragility fracture and would be eligible for treatment for this reason. Using age-dependent thresholds, an additional 2.6% of women (0.3% of men) were eligible for treatment in that MOF probabilities lay above the upper assessment threshold. A BMD test would be recommended in 5% of men and 38% of women. With hybrid thresholds, an additional 13% of women (3.6% of men) were eligible for treatment and BMD recommended in 11% of men and 42% of women. The application of hybrid intervention thresholds ameliorates the disparity in fracture probabilities seen with age-dependent thresholds. Probability-based assessment of fracture risk, including the use of the hybrid intervention thresholds for Chile, is expected to help guide decisions about treatment.

Primary hyperparathyroidism and fracture probability.

Primary hyperparathyroidism (PHPT) is associated with an increase in the risk of fracture. In FRAX, the increase in risk is assumed to be mediated by low bone mineral density (BMD). However, the risk of death is also increased and its effect on fracture probability is not known. The aim of this study was to determine whether PHPT affects hip fracture and major osteoporotic fracture risk independently of bone mineral density (BMD) and whether this and any increase in mortality affects the assessment of fracture probability. A register-based survey of patients with PHPT and matched controls in Denmark were identified from hospital registers. The incidence of death, hip fracture, and major osteoporotic fracture were determined for computing fracture probabilities excluding time after parathyroidectomy. The gradient of risk for fracture for differences in BMD was determined in a subset of patients and in BMD controls. The severity of disease was based on serum calcium and parathyroid hormone levels. We identified 6884 patients with biochemically confirmed PHPT and 68,665 matched population controls. On follow-up, excluding time after parathyroidectomy in those undergoing surgery, patients with PHPT had a higher risk of death (+52%), hip fracture (+48%), and major osteoporotic fracture (+36%) than population controls. At any given age, average 10-year probabilities of fracture were higher in patients with PHPT than population controls. The gradient of fracture risk with differences in BMD was similar in cases and controls. Results were similar when confined to patients not undergoing parathyroidectomy. Fracture probability decreased with the severity of disease due to an increase in mortality rather than fracture risk. The risk of hip and other major osteoporotic fracture is increased in PHPT irrespective of the disease severity. Fracture probability was attenuated due to the competing effect of mortality. The increased fracture risk in patients treated conservatively argues for widening the indications for parathyroidectomy in mild PHPT.

An investigation into the hammer toe effects on the lower extremity mechanics and plantar fascia tension: A case for a vicious cycle and progressive damage

Hammer toes are one of the common deformities of the forefoot that can lead to compensatory changes during walking in individuals with this condition. Predicting the adverse effects of tissue damage on the performance of other limbs is very important in the prevention of progressive damage. Finite element (FE) and musculoskeletal modeling can be helpful by allowing such effects to be studied in a way where the internal stresses in the tissue could be investigated. Hence, this study aims to investigate the effects of the hammer toe deformity on the lower extremity, especially on the plantar fascia functions. To compare the joint reactions of the hammer toe foot (HTF) and healthy foot (HF), two musculoskeletal models (MSM) of the feet of a healthy individual and that of a participant with hammer toe foot were developed based on gait analysis. A previously validated 3D finite element model which was constructed using Magnetic Resonance Imaging (MRI) of the diabetic participant with the hammer toe deformity was processed at five different events during the stance phase of gait.It was found that the hammer toe deformity makes dorsiflexion of the toes and the windlass mechanism less effective during walking. Specifically, the FE analysis results showed that plantar fascia (PF) in HTF compared to HF played a less dominant role in load bearing with both medial and lateral parts of PF loaded. Also, the results indicated that the stored elastic energy in PF was less in HTF than the HF, which can indicate a higher metabolic cost during walking. Internal stress distribution shows that the majority of ground reaction forces are transmitted through the lateral metatarsals in hammer toe foot, and the probability of fifth metatarsal fracture and also progressive deformity was subsequently increased. The MSM results showed that the joint reaction forces and moments in the hammer toe foot have deviated from normal, where the metatarsophalangeal joint reactions in the hammer toe were less than the values in the healthy foot. This can indicate a vicious cycle of foot deformity, leading to changes in body weight force transmission line, and deviation of joint reactions and plantar fascia function from normal. These in turn lead to increased internal stress concentration, which in turn lead to further foot deformities. This vicious cycle cause progressive damage and can lead to an increase in the risk of ulceration in the diabetic foot.

РАСЧЕТНО-ЭКСПЕРИМЕНТАЛЬНОЕ ИССЛЕДОВАНИЕ ДИНАМИЧЕСКОЙ НАГРУЖЕННОСТИ ЭНЕРГОСИЛОВОГО БЛОКА ТРАНСПОРТНОЙ МАШИНЫ

The article presents the results of a computational and experimental study of the dynamic loading of the transmission of a transport vehicle with an increased power diesel engine. The novelty of the study is substantiated in the scientifically based applicability of elastic torsion shafts between the engine and transmission as a torsional vibration damper, as well as in the development of a new experimental definition of the dynamic value of torque based on the principle of modulation of high-frequency oscillations of the signal of standard pulse speed sensors by modulating vibrations occurring in the power unit of the transport vehicle. As a result, the main calculated motor-frequency function of acceleration (torque) is obtained, including engine harmonics, harmonic components formed by the mechanisms of the connecting rod-piston and gas distribution mechanisms of the engine, the generator drive, vibrations in the transmission, etc. It is established that the reason for the limitation of the durability of torsion shafts is their operation in off-design modes due to the occurrence of a phenomenon called “task conflict”. On the basis of probabilistic calculations, a high comparative assessment of the probability of sudden fracture of elastic shafts at design and off-design loading modes is carried out. Based on the research results, a conclusion is made on the applicability of torsion shafts as dampers of torsional vibrations in the power unit with increased power.

Predicting the Subsequent Contralateral Hip Fracture: Is FRAX the Answer?

To (1) determine the ability of the Fracture Risk Assessment Tool (FRAX) to identify the probability of contralateral hip fractures within 2 years of index fracture and (2) identify independent risk factors for a subsequent hip fracture. Retrospective. Urban, academic medical center. This study included a consecutive series of patients treated for unilateral hip fractures between September 2015 and July 2019. Eight hundred thirty-two consecutive patients were included in the analysis with a mean age of 81.2 ± 9.9 years. Thirty-one (3.7%) patients sustained a contralateral hip fracture within 2 years with these patients sustaining the second fracture at a mean 294.1 days ± 197.7 days. The average FRAX score for the entire cohort was 11.9 ± 7.4, and the area under receiving operating characteristic curve (AUROC) for FRAX score was 0.682 (95% CI, 0.596-0.767). Patients in the high-risk FRAX group had a >7% risk of contralateral hip fracture within 2 years. Independent risk factors for contralateral hip fracture risk included patient age 80 years or older and decreasing BMI. This study demonstrates the strong ability of the FRAX score to triage patients at risk of subsequent contralateral hip fracture within 2 years. In this high-risk FRAX group, patients age older than 80 years and who have decreasing BMI after their index fracture have a 12.5% increased risk of fracture within 2 years which is 4× higher than the current World Health Organization 10-year 3% hip fracture risk standard used to initiate pharmacologic treatment. Therefore, high-risk patients identified using this methodology should be targeted more aggressively with preventative measures including social, medical, and potentially surgical interventions. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The automized fracture edge detection and generation of three-dimensional fracture probability heat maps

With proven impact of statistical fracture analysis on fracture classifications, it is desirable to minimize the manual work and to maximize repeatability of this approach. We address this with an algorithm that reduces the manual effort to segmentation, fragment identification and reduction. The fracture edge detection and heat map generation are performed automatically. With the same input, the algorithm always delivers the same output. The tool transforms one intact template consecutively onto each fractured specimen by linear least square optimization, detects the fragment edges in the template and then superimposes them to generate a fracture probability heat map. We hypothesized that the algorithm runs faster than the manual evaluation and with low (< 5mm) deviation. We tested the hypothesis in 10 fractured proximal humeri and found that it performs with good accuracy (2.5mm ± 2.4mm averaged Euclidean distance) and speed (23 times faster). When applied to a distal humerus, a tibia plateau, and a scaphoid fracture, the run times were low (1-2min), and the detected edges correct by visual judgement. In the geometrically complex acetabulum, at a run time of 78min some outliers were considered acceptable. An automatically generated fracture probability heat map based on 50 proximal humerus fractures matches the areas of high risk of fracture reported in medical literature. Such automation of the fracture analysis method is advantageous and could be extended to reduce the manual effort even further.

Effect of annealing treatment on the mechanical properties of spiked-shell aerographite particles

The spiked-shell microparticles of aerographite exhibit excellent flexibility owing to their unique shell structures consisting of radially aligned hollow carbon nanorods. However, their flexibility is likely transitory, and fatigue damages related to imperfections in the crystallinity of their graphitic layers are observed upon cyclic deformation. In this study, aerographite microparticles were heat treated to examine the effects of annealing on their crystallinity and mechanical behaviors. Experimental results showed that the crystallinity of the particles was improved by annealing above 1600 °C; however, excess annealing at 2000 °C caused severe changes in the shell morphology, leading to a lack of flexibility. Single-particle-level compressive test results showed that the particles annealed at 1600 °C performed significantly better in terms of mechanical behaviors by reducing the probability of fracture due to large crack propagation. These particles also exhibited excellent flexibilities in their stress–strain relationships even after 100-times cycle tests. These findings suggest that annealing treatment at 1600 °C is an effective option to improve the mechanical properties of aerographite particles.

Static and dynamic analyses of the effects of shim material stiffness on insert crack initiation and propagation

Microcracks can form on the surface or inside an insert during forming or cutting processes. These microcracks tend to expand rapidly under impact loading, eventually leading to tool fracture and failure. Fracture and breakage of inserts cause significant limitations to the improvement of processing efficiency and safe production. This study investigated the effects of shim stiffness (using Young's modulus) on the stress distribution in the insert and at the crack tip under static and dynamic (impact) loading conditions, thereby providing a theoretical basis for correctly designing and selecting inserts for indexable tools. The extended finite element method (XFEM) was used to develop a 3D simulation model for an insert–shim system. The model was used to study crack initiation and expansion in the insert for different rigid shims under static and dynamic loading. Analyses of the crack tip stress intensity factor, the maximum principal stress, the strain, and the angle and direction of crack deflection were performed. Additionally, interrupted cutting experiments were conducted with cemented-carbide tools for four rigid shim materials. It was concluded that under static loading conditions, a weakly rigid shim reduced the crack tip stress intensity factor and the maximum principal stress, thus reducing the probability of insert fracture and that the stiffness of the shim has no effect on the angle of crack deflection on the insert surface. The shim stiffness has a more obvious effect on the crack propagation length and internal propagation direction during dynamic loading, and a weakly rigid shim increases the deflection angle as the crack expands inside the insert, thereby reducing the downward fracture length.

Greater pQCT Calf Muscle Density Is Associated with Lower Fracture Risk, Independent of FRAX, Falls and BMD: A Meta-Analysis in the Osteoporotic Fractures in Men (MrOS) Study.

We investigated the predictive performance of peripheral quantitative computed tomography (pQCT) measures of both calf muscle density (an established surrogate for muscle adiposity, with higher values indicating lower muscle adiposity and higher muscle quality) and size (cross-sectional area [CSA]) for incident fracture. pQCT (Stratec XCT2000/3000) measurements at the tibia were undertaken in Osteoporotic Fractures in Men (MrOS) United States (US), Hong Kong (HK), and Swedish (SW) cohorts. Analyses were by cohort and synthesized by meta-analysis. The predictive value for incident fracture outcomes, illustrated here for hip fracture (HF), using an extension of Poisson regression adjusted for age and follow-up time, was expressed as hazard ratio (HR) per standard deviation (SD) increase in exposure (HR/SD). Further analyses adjusted for femoral neck (fn) bone mineral density (BMD) T-score, Fracture Risk Assessment Tool (FRAX) 10-year fracture probability (major osteoporotic fracture) and prior falls. We studied 991 (US), 1662 (HK), and 1521 (SW) men, mean ± SD age 77.0 ± 5.1, 73.9 ± 4.9, 80 ± 3.4 years, followed for a mean ± SD 7.8 ± 2.2, 8.1 ± 2.3, 5.3 ± 2.0 years, with 31, 47, and 78 incident HFs, respectively. Both greater muscle CSA and greater muscle density were associated with a lower risk of incident HF [HR/SD: 0.84; 95% confidence interval [CI], 0.72-1.0 and 0.78; 95% CI, 0.66-0.91, respectively]. The pattern of associations was not materially changed by adjustment for prior falls or FRAX probability. In contrast, after inclusion of fn BMD T-score, the association for muscle CSA was no longer apparent (1.04; 95% CI, 0.88-1.24), whereas that for muscle density was not materially changed (0.69; 95% CI, 0.59-0.82). Findings were similar for osteoporotic fractures. pQCT measures of greater calf muscle density and CSA were both associated with lower incidence of fractures in older men, but only muscle density remained an independent risk factor for fracture after accounting for fn BMD. These findings demonstrate a complex interplay between measures of bone, muscle size, and quality, in determining fracture risk. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Prevalence of Vertebral Compression Fracture Among Rheumatoid Arthritis Patients in Sulaymaniyah

Background: The risk of fractured vertebral increases in patients with rheumatoid arthritis as they are more likely to suffer from osteopenia, and osteoporosis. Objectives: This study aimed to investigating the rate and risk factors of vertebral fractures in patients with rheumatoid arthritis. Methods: We recruited 201 patients aged between 30 and 70 who attended the rheumatology department at Shahid Hemn Teaching Hospital in Sulaymaniyah, between January and September 2022. Medical records were reviewed for disease and treatment characteristics while also clinically evaluated by a rheumatologist. Spinal radiographs were assessed by two experienced radiologists blinded to patients’ clinical diagnosis and status. Compression fractures were classified by using the Genant semiquantitative method, and the type of fracture was classified as wedged fracture, biconcave fracture, or crushed fracture. Results: Of the 201 included participants, 151 were female, and 50 were male. The BMI of women was higher than men by nearly four points (P&lt;0.001). Most women were also illiterate (68/151, 45.0%) and unemployed (139/151, 92.1%). Hypertension (28.4%) and diabetes mellitus (14.4%) were the most reported comorbidities. Women were more likely to have higher DAS28 scores while men had more vertebral fractures (P=0.003). The probability of fractures increased with age, male sex, and illiteracy compared to primary school, osteopenia, and osteoporosis through simple and multiple logistic regression models. Conclusion: With at least one fracture affects females and males at a rate of 27.8% and 52.0%, respectively. Also reported that age, male sex, illiteracy, osteopenia, and osteoporosis significantly increase the risk of fractures.

Osteoporosis treatment in Austria—assessment of FRAX-based intervention thresholds for high and very high fracture risk

SummaryThe adoption of the management pathway proposed by the National Osteoporosis Guideline Group (NOGG), UK applied using the Austrian FRAX® tool in a referral population of Austrian women categorises 22–29% of women age 40 years or more eligible for treatment of whom 28–34% are classified at very high risk.PurposeThe aim of this study is to provide a reference document for the further development of existing guidelines for the management of osteoporosis in Austria, considering FRAX-based intervention thresholds for high and very high fracture risk.MethodsThe model development was based on two Austrian hospital referral cohorts. Baseline information was collected to compute the 10-year probability (using the Austrian FRAX model) of a major osteoporotic fracture (MOF) and hip fracture both with and without the inclusion of femoral neck bone mineral density (BMD). Assessment thresholds for BMD testing were defined, as well as intervention thresholds. In addition, thresholds that characterise men and women at high and very high fracture risk were established. The management pathway followed that currently recommended by the UK National Osteoporosis Guideline Group (NOGG).ResultsThe two cohorts comprised a total of 1306 women and men with a mean age of 66.7 years. Slightly more than 50% were eligible for treatment by virtue of a prior fragility fracture. In those women without a prior fracture, 22% (n = 120) were eligible for treatment based on MOF probabilities. Of these, 28% (n = 33) were found to be at very high risk. When both MOF and hip fracture probabilities were used to characterise risk, 164 women without a prior fracture were eligible for treatment (29%). Of these, 34% (n = 56) were found to be at very high risk. Fewer men without prior fracture were eligible for treatment compared with women.ConclusionThe management pathway as currently outlined is expected to reduce inequalities in patient management. The characterisation of very high risk may aid in the identification of patients suitable for treatment with osteoanabolic agents.

Cardiovascular, bone, and metabolic health in men with castrate-resistant prostate cancer treated with androgen deprivation: a matched cohort study

Background Descriptive data on late effects associated with castrate-resistant prostate cancer (CRPC) are sparse. We aimed to define the timing and incidence of cardiovascular disease (CVD), fractures, and diabetes in a patient population with CRPC. Methods In the population-based STHLM0 cohort 1464 men with CRPC were identified and matched with three men free from prostate cancer (PC) in the Stockholm region of Sweden. Kaplan–Meier estimates of net survival were used to describe time to CVD, fracture, and diabetes. Cox regression was used to compare incidence rates (IRRs) for the respective late effects. Cumulative incidence analyses of late effects in the presence of the competing risk of death were performed to estimate absolute risks. Results The Kaplan Meier estimates demonstrated a higher net probability for CVD, fracture, and diabetes among men diagnosed with CRPC compared to the matched comparators. The IRRs were 1.94 (95% CI: 1.79–2.12) for CVD, 2.08 (95% CI: 1.70–2.53) for fracture, and 2.00 (95% CI: 1.31–3.05) for diabetes, respectively, comparing men diagnosed with CRPC to men free from PC. The cumulative incidence of CVD at 12 months of follow-up was higher in men diagnosed with CRPC compared to healthy controls regardless of age with a difference in cumulative incidence being 0.20 for men aged <65 and 0.11 for men aged >84. Conclusions In this cohort, the incidence of CVD was significantly higher among men with CRPC compared to healthy controls. Despite having this end-stage disease this finding proves that clinicians must recognize this late effect in men diagnosed with CRPC to improve preventive actions. These men did not have a higher absolute risk of fractures and diabetes after accounting for deaths due to any cause compared to healthy controls.

Strengthening Process by Electron Beam to Carbon Fiber for Impact Strength Enhancement of Interlayered Thermoplastic-Polypropylene Carbon Fiber Composite.

Strong adhesion between recyclable thermoplastic (TP) polymer and carbon fiber (CF) has always been highly sought after. Therefore, for an interlayered CF reinforced TP polypropylene (CFRTPP) composite composed of 3 sized CF plies, alternating between 4 PP sheets, designated [PP]4[CF]3, a process of activating CF plies directly on both sides with homogeneous low energy electron beam irradiation (EBI) under N2 gas, prior to lamination assembly and hot press of 4.0 MPa at 493 K for 3 min was carried out. Experimental results showed EBI dose of 43.2, 129, or 216 kGy significantly raised Charpy impact values, auc at all fracture probabilities, Pf. The 129 kGy dose appeared to be at or near optimum increasing auc 103%, 83%, and 65% at low-, median-, and high-Pf = 0.07, 0.50, and 0.93; while raising statistically lowest impact value, as at Pf = 0 calculated by 3-dimensional Weibull equation about 110%, indicating increased safety and reliability. It is assumed dangling bonds generated by the EBI rapidly form covalent bonds CF:C:O:C:PP and CF:C:C:PP at the interface, along with cross-linking in the PP near the CF. This is by charge transfer from CF to PP.

261 HIGH FRACTURE RISK IN OLDER IRISH ADULT FALLERS

Abstract Background Fracture risk due to falls depends on several factors including bone density, quality and size, hip geometry (axis length), direction of fall (forward, backwards or sideways), body mass index (BMI), type of surface impacted, body site of impact and mechanism of fall (eg syncope). We aimed to identify the fracture risk per fall in frail older Irish adults. Methods Participants were from the hypertensive and cognitive cohort of the Trinity, Ulster, Dept Agriculture (TUDA) study of Irish adults (aged &amp;gt;60) recruited from hospital outpatient services and GP practises. Falls and falls resulting in fracture in the previous year were self-reported so those with an MMSE &amp;lt; 25 were excluded to avoid recall bias. We identified fallers, recurrent fallers and fractures due to falls in the previous year. Results 892 fallers, mean age 76.3 ± 8.4 yrs, 65.2% female. 23.8% had 2 falls and 24.2% ≥3 falls. Mean timed up and go was 17.3 ± 9.5 seconds. Commonest fracture due to falls were hip (20.1%), upper limb (18.5%) and lower limb (17.9%) with one fracture of neck and skull. Fracture rate per fall was 7.1%: 1.7% for hip, 1.3% for lower and 1.2% for upper limb. Annual fracture rate per faller was 16.5%. The only predictors of fall with fracture versus no fracture were female sex (OR 2.4, 1.6-3.6, P&amp;lt;0.001) and lower body mass index (P=0.001). Conclusion We identified similar hip fracture rates (1.7%) due to falls as in other studies. However, one in six fallers had sustained a fracture in the previous year reflecting the high proportion of recurrent fallers. Lower BMI and female sex predicted fall with fracture as both are strongly correlated with risk of osteoporosis. Recent guidelines now factor in recurrent falls when estimating the probability of future osteoporotic fractures.

64 HIGH-DOSE STEROIDS IN HAEMATOLOGICAL MALIGNANCY: A RED FLAG FOR BONE HEALTH

Abstract Background Bone-protective treatment should always be considered when commencing glucocorticoid therapy in individuals at high risk of fracture, as outlined in recent guidelines (National Osteoporosis Guideline Group, July 2018). Despite this, many patients receive high dose glucocorticoids (&amp;gt;7.5mg/kg/day or equivalent for &amp;gt;3 months) during treatment of haematological malignancy without formal assessment of bone health. Methods Twenty-five patients with Non-Hodgkin’s Lymphoma (NHL) on high dose steroid chemotherapy protocols were retrospectively assessed. The inclusion criterion was defined as any patient commenced on a cyclophosphamide, doxorubicin, vincristine and prednisolone (CHOP) containing protocol from 1/8/2020 to 1/8/21. Data was collected from electronic and written patient records. Information regarding patient age, diagnosis, steroid preparation and dose, presence of risk factors for osteoporosis and calcium and vitamin D prescriptions were collected. Radiological imaging was reviewed to assess for the occurrence of fragility fractures. Each patient had a FRAX® score calculated to assess fracture risk. Results The mean age of patients studied was 67 years and equally distributed between males and females. All patients had NHL. 32% (n=25) of patients were identified to be at high risk for fracture (FRAX® score &amp;gt;20% ten-year probability of major osteoporotic fracture). 16% had already established fragility fractures prior to commencing steroid treatment. 28% of patients were females over the age of 70 years. Only 12% of patients received vitamin D and calcium supplementation. No patient commenced bone protection therapy. Conclusion Omission of bone health assessment prior to high dose glucocorticoid treatment is prevalent in haematological malignancy and places patients at risk of significant morbidity. Patients are not routinely considered for protective measures including calcium and vitamin D supplementation and bone protection therapy. A simple risk-assessment tool and education to staff and patients prior to glucocorticoid therapy could significantly improve practice in this area. It is now planned to introduce routine risk assessment for this cohort of patients, with re-audit following implementation.

The role and place of the FRAX calculator in initiation osteoporosis treatment: an analysis of the osteoporosis center registry

Background:The growing frequency of fractures associated with osteoporosis, the significant costs of their treatment, disability and increased mortality make it an important and urgent task to optimize the diagnosis and treatment of osteoporosis in the Russian Federation.Aim: The aim of this study was analyzed of using modern diagnostic criteria for osteoporosis by specialists when they making a clinical decision to initiate treatment for osteoporosis, including an estimate of the 10-year probability of fractures according to FRAX.Materials and methods: The study was conducted in the city consultative and diagnostic center for the prevention of osteoporosis, St. Petersburg. The register of the osteoporosis center for 2018–2021 was used to select patients for the study. Based on the analysis of registry data, a sample of 362 patients with newly diagnosed osteoporosis was obtained. In the resulting sample, the existing FRAX value was assessed on the therapeutic intervention threshold graph, all of them analyzed the primary medical documentation, as well as the available DXA densitometry data.Results: In this study, we assessed the place of FRAX 10-year risk of major osteoporotic fractures in the clinical decision of an osteoporosis specialist to start anti-osteoporosis therapy, in this case taken as the «gold standard». The study found that a positive FRAX score had a high predictive value of 100%. In contrast, the negative predictive value was very low (19.5%): a FRAX value below the intervention threshold did not guarantee a truly low fracture risk and no need to start osteoporosis treatment.Conclusion: Despite the fact that both densitometry and FRAX have significant limitations in use, and cannot identify all patients with a high risk of fractures, their combined use increases the prognostic value of the methods. FRAX technology in routine practice allows, in addition to clinical and instrumental methods for diagnosing high-risk fractures, to identify candidates for the treatment of osteoporosis, and should be used in accordance with clinical recommendations.