Fracture Events Research Articles

Comparative analysis of acoustic emissions produced in abrupt and non-abrupt fracture processes in reinforced concrete walls

The determination of the eventual abrupt fracture of a reinforced concrete structure is of fundamental importance to estimate and mitigate the possible damages caused by its failure; of particular importance are shear-type fractures since these usually lead to sudden failure of the structure. One way to determine the presence of shear-type micro-cracks is by parametric analysis of the acoustic emissions produced by the micro-cracks during their growth. In this analysis, a direct comparisson of the waveform allows a distinction to be made between tensile-type and shear-type events. In the present study, we performed a comparative analysis of fracture processes in two reinforced concrete walls. In one of the walls an out-of-plane force was applied leading to bending and a non-abrupt failure; in the other one diagonal forces were applied leading to an abrupt shear-type fracture. Acoustic emissions were detected throughout and we found that at least one of the parameters associated with the parametric analysis allows distinguishing between abrupt and non-abrupt failures. Our results suggest that parametric analysis of acoustic emissions could be a useful tool in the prediction of abrupt failures in reinforced concrete structures.

P-151: Incidence of adverse events in patients with Multiple Myeloma who continued with Denosumab after receiving Denosumab or Zoledronic acid: an open-label extension study

<h3>Background</h3> In a randomized phase 3 study of denosumab (XG) vs zoledronic acid (ZA) in patients with newly diagnosed multiple myeloma (MM) (Raje et al. Lancet Oncol 2018), XG was shown to be non-inferior to ZA and had a safety profile comparable to that of ZA with less renal toxicity. The mean treatment duration was 17.5 months for XG, and interest remains on the long-term safety profile of XG. Here, we report safety in the open-label extension (OLE) phase of this study of further XG treatment in patients with newly diagnosed MM. <h3>Methods</h3> This was an international, phase 3, randomized, double-blind, active-controlled study comparing XG with ZA in patients with newly diagnosed MM (NCT01345019). Due to the positive benefit-risk profile of XG, patients were offered open-label XG for up to 2 years. In the OLE phase, eligible patients receiving XG or ZA from the double-blind phase continued with or switched to XG that was administered subcutaneously at 120 mg every 4 weeks. Patients who received XG in the double-blind phase are designated as XG/XG (n = 426), while those receiving ZA are designated as ZA/XG (n = 418). All patients were strongly recommended to receive vitamin D and calcium supplementation, necessary to treat or prevent hypocalcemia. <h3>Results</h3> The cumulative mean exposure to XG for the entire study period consisting of double-blind and OLE phases was 29.2 months. The cumulative mean exposure to XG in the OLE phase was 17.5 months for XG/XG and 17.6 months for ZA/XG patients. Among 844 patients who received open-label XG, 443 (52.5%) were male, 401 (47.5%) were female, and the median age was 62 years. At diagnosis, 303 (35.9%) patients were at ISS stage I, 315 (37.3%) at stage II, and 208 (24.6%) at stage III. At study entry, 557 (66.0%) patients had a history of skeletal-related events. During the OLE phase, 361 (84.7%) XG/XG and 366 (87.6%) ZA/XG patients had treatment-emergent adverse events (AEs). Treatment-emergent AEs led to discontinuation of the investigational product in 99 (23.2%) XG/XG and 81 (19.4%) ZA/XG patients. The treatment-emergent AEs of interest for XG/XG and ZA/XG patients, respectively, in the OLE phase included hypocalcemia (7.0%, 7.2%), AEs potentially associated with hypersensitivity (12.0%, 11.5%), musculoskeletal pain (32.4%, 33.7%), and infections and infestations (55.9%, 58.1%). The incidence of positively adjudicated osteonecrosis of the jaw (ONJ) that occurred during the OLE phase was 7.7% for XG/XG (grade 3: 2.3%) and 6.2% for ZA/XG (grade 3: 2.4%). No adjudicated positive atypical femur fracture events were reported. As of October 25, 2019, a notably higher number of ONJ events resolved in XG/XG patients (14 [42%]) than in ZA/XG patients (6 [23%]). <h3>Conclusions</h3> The safety results were comparable to those of previous skeletal-related event studies. XG has an acceptable safety profile when administered for >2 years in patients with MM.

Sensitivity and specificity of modified RUST score using clinical and radiographic findings as a gold standard.

AimsThe modified Radiological Union Scale for Tibia (mRUST) fractures score was developed in order to assess progress to union and define a numerical assessment of fracture healing of metadiaphyseal fractures. This score has been shown to be valuable in predicting radiological union; however, there is no information on the sensitivity, specificity, and accuracy of this index for various cut-off scores. The aim of this study is to evaluate sensitivity, specificity, accuracy, and cut-off points of the mRUST score for the diagnosis of metadiaphyseal fractures healing.MethodsA cohort of 146 distal femur fractures were retrospectively identified at our institution. After excluding AO/OTA type B fractures, nonunions, follow-up less than 12 weeks, and patients aged less than 16 years, 104 sets of radiographs were included for analysis. Anteroposterior and lateral femur radiographs at six weeks, 12 weeks, 24 weeks, and final follow-up were separately scored by three surgeons using the mRUST score. The sensitivity and specificity of mean mRUST score were calculated using clinical and further radiological findings as a gold standard for ultimate fracture healing. A receiver operating characteristic curve was also performed to determine the cut-off points at each time point.ResultsThe mean mRUST score of ten at 24 weeks revealed a 91.9% sensitivity, 100% specificity, and 92.6% accuracy of predicting ultimate fracture healing. A cut-off point of 13 points revealed 41.9% sensitivity, 100% specificity, and 46.9% accuracy at the same time point.ConclusionThe mRUST score of ten points at 24 weeks can be used as a viable screening method with the highest sensitivity, specificity, and accuracy for healing of metadiaphyseal femur fractures. However, the cut-off point of 13 increases the specificity to 100%, but decreases sensitivity. Furthermore, the mRUST score should not be used at six weeks, as results show an inability to accurately predict eventual fracture healing at this time point.Cite this article: Bone Jt Open 2021;2(10):796–805.

Study on the Key Technology of Controlling the Instability of Deep High-Stress Coal and Rock Mass and Relieving the Danger

In order to solve the problem of stress concentration and gas overrun in the process of uncovering high gas and thick coal seam, combined with the occurrence characteristics of coal seams in Wuyang Coal Mine, the measures of “hydraulic and mechanical cavity making + steel screen pipe + surrounding rock grouting” are adopted to establish a method for mutual verification of multiple effect test indexes of residual stress, residual gas content, coal seam moisture content, and microseismic signal characteristics, and the three-dimensional accurate analysis of the influence range of hydraulic cavitation is effectively realized. By comparing and analyzing the gas extraction amount, the surrounding borehole stress change and the microseismic monitoring signals before and after the application of hydraulic cavitation technology are studied. The results show the following. (1) The pressure relief effect of the hydraulic cavity on surrounding coal decreases with the increase of distance, and the pressure relief effect is most obvious at 1.0∼2.5 m, in the range of 2.5–3.5 m around the hydraulic drilling hole, the duration, rate, and amplitude of pressure relief are reduced compared with those in the range of less than 2.5 m, while in the range of more than 3.5 m, the effect of pressure relief is very weak. (2) During the period of hydraulic cavitation release hole, the radius of water supply to coal seam is within 1.5 m, which accounts for 79% of coal wall area. (3) It is also a process where the stress distribution in the coal and rock body needs to be rebalanced before and after hydraulic caverning, which is often accompanied by microfracture of coal and rock mass. The analysis shows that, before hydraulic caverning, the waveform of coal and rock fracture signal has a short duration, large amplitude, and obvious signal mutation, and the dominant frequency of the signal is about 250 Hz, with large total energy. After hydraulic caverning, the intensity of coal and rock fracture events is greatly reduced. The research results can effectively identify the influence range of hydraulic cavitation, improve the detection accuracy and efficiency of hydraulic cavitation range, effectively predict and warn the hidden danger of mine safety, and provide a reference for the work of similar mines.

Circulating p-Cresyl Sulfate, Non-Hepatic Alkaline Phosphatase and Risk of Bone Fracture Events in Chronic Kidney Disease-Mineral Bone Disease.

Patients with chronic kidney disease (CKD), especially those undergoing hemodialysis, are at a considerably high risk of bone fracture events. Experimental data indicate that uremic toxins intricately involved in bone-related proteins exert multi-faced toxicity on bone cells and tissues, leading to chronic kidney disease–mineral and bone disorder (CKD-MBD). Nonetheless, information regarding the association between p-cresyl sulfate (PCS), non-hepatic alkaline phosphatase (NHALP) and skeletal events remains elusive. We aim to explore the association between PCS, NHALP and risk of bone fracture (BF) in patients with hemodialysis. Plasma concentrations of PCS and NHALP were ascertained at study entry. Cox proportional hazard regression analyses were used to determine unadjusted and adjusted hazard ratios (aHRs) of PCS for BF risk. In multivariable analysis, NHALP was associated with incremental risks of BFs [aHR: 1.06 (95% CI: 1.01–1.11)]. The association between the highest PCS tertile and BF risk remained robust [aHR: 2.87 (95% CI: 1.02–8.09)]. With respect to BF events, the interaction between NHALP and PCS was statistically significant (p value for the interaction term < 0.05). In addition to mineral dysregulation and hyperparathyroidism in hemodialysis patients, higher circulating levels of PCS and NHALP are intricately associated with incremental risk of BF events, indicating that a joint evaluation is more comprehensive than single marker. In light of the extremely high prevalence of CKD-MBD in the hemodialysis population, PCS may act as a pro-osteoporotic toxin and serve as a potential surrogate marker for skeletal events.

Sodium-glucose cotransporter-2 Inhibitors in Heart Failure: An Updated Systematic Review and Meta-analysis of 13 Randomized Clinical Trials Including 14,618 Patients With Heart Failure.

Sodium-glucose cotransporter-2 (SGLT-2) inhibitors showed benefit in patients with heart failure. In this updated meta-analysis, we evaluate the therapeutic efficacy and safety of SGLT-2 inhibitors in patients with heart failure. Different electronic databases were searched to find relevant articles. RevMan 5.4 was used for pooling data using a random/fixed-effects model, complemented by several sensitivity and subgroup analyses. A total of 13 randomized clinical trials including 14,618 patients with heart failure were included in analysis among 6797 studies screened. The overall mortality rate was 12.45% in the SGLT-2 group and 14.67% in the placebo group with 18% lower odds of overall mortality [odds ratio (OR), 0.82; confidence interval (CI), 0.75-0.91] in the SGLT-2 group. Odds of cardiovascular mortality was 18% lower (OR, 0.82; CI, 0.74-0.92) in the SGLT-2 group. The odds of hospitalization for heart failure (HHF) was 38% lower during the study period (OR, 0.62; CI, 0.56-0.68) in the SGLT-2 group. In addition, a benefit was seen for composite outcome HHF or mortality and considering subgrouping based on diabetes status, gender, and age groups. Although genital infection was significantly higher in the SGLT-2 group, the occurrence of severe adverse events, hypoglycemia, urinary tract infection, bone fracture, volume depletion, and other renal events did not differ between the 2 groups. Thus, SGLT-2 inhibitors improved cardiovascular outcomes among patients with heart failure with no significant difference in adverse events. Clinical benefit was comparable in diabetic and nondiabetic individuals, males and females, people in younger and older age groups with underlying heart failure, and HF with reduced ejection fraction.

Pharmacological interventions versus placebo, no treatment or usual care for osteoporosis in people with chronic kidney disease stages 3-5D.

Chronic kidney disease (CKD) is an independent risk factor for osteoporosis and is more prevalent among people with CKD than among people who do not have CKD. Although several drugs have been used to effectively treat osteoporosis in the general population, it is unclear whether they are also effective and safe for people with CKD, who have altered systemic mineral and bone metabolism. To assess the efficacy and safety of pharmacological interventions for osteoporosis in patients with CKD stages 3-5, and those undergoing dialysis (5D). We searched the Cochrane Kidney and Transplant Register of Studies up to 25 January 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. Randomised controlled trials comparing any anti-osteoporotic drugs with a placebo, no treatment or usual care in patients with osteoporosis and CKD stages 3 to 5D were included. Two review authors independently selected studies, assessed their quality using the risk of bias tool, and extracted data. The main outcomes were the incidence of fracture at any sites; mean change in the bone mineral density (BMD; measured using dual-energy radiographic absorptiometry (DXA)) of the femoral neck, total hip, lumbar spine, and distal radius; death from all causes; incidence of adverse events; and quality of life (QoL). Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) for continuous outcomes. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Seven studies involving 9164 randomised participants with osteoporosis and CKD stages 3 to 5D met the inclusion criteria; all participants were postmenopausal women. Five studies included patients with CKD stages 3-4, and two studies included patients with CKD stages 5 or 5D. Five pharmacological interventions were identified (abaloparatide, alendronate, denosumab, raloxifene, and teriparatide). All studies were judged to be at an overall high risk of bias. Among patients with CKD stages 3-4, anti-osteoporotic drugs may reduce the risk of vertebral fracture (RR 0.52, 95% CI 0.39 to 0.69; low certainty evidence). Anti-osteoporotic drugs probably makes little or no difference to the risk of clinical fracture (RR 0.91, 95% CI 0.79 to 1.05; moderate certainty evidence) and adverse events (RR 0.99, 95% CI 0.98 to 1.00; moderate certainty evidence). We were unable to incorporate studies into the meta-analyses for BMD at the femoral neck, lumbar spine and total hip as they only reported the percentage change in the BMD in the intervention group. Among patients with severe CKD stages 5 or 5D, it is uncertain whether anti-osteoporotic drug reduces the risk of clinical fracture (RR 0.33, 95% CI 0.01 to 7.87; very low certainty evidence). It is uncertain whether anti-osteoporotic drug improves the BMD at the femoral neck because the certainty of this evidence is very low (MD 0.01, 95% CI 0.00 to 0.02). Anti-osteoporotic drug may slightly improve the BMD at the lumbar spine (MD 0.03, 95% CI 0.03 to 0.04, low certainty evidence). No adverse events were reported in the included studies. It is uncertain whether anti-osteoporotic drug reduces the risk of death (RR 1.00, 95% CI 0.22 to 4.56; very low certainty evidence). Among patients with CKD stages 3-4, anti-osteoporotic drugs may reduce the risk of vertebral fracture in low certainty evidence. Anti-osteoporotic drugs make little or no difference to the risk of clinical fracture and adverse events in moderate certainty evidence. Among patients with CKD stages 5 and 5D, it is uncertain whether anti-osteoporotic drug reduces the risk of clinical fracture and death because the certainty of this evidence is very low. Anti-osteoporotic drug may slightly improve the BMD at the lumbar spine in low certainty evidence. It is uncertain whether anti-osteoporotic drug improves the BMD at the femoral neck because the certainty of this evidence is very low. Larger studies including men, paediatric patients or individuals with unstable CKD-mineral and bone disorder are required to assess the effect of each anti-osteoporotic drug at each stage of CKD.

Constraining Europa's ice shell thickness with fundamental mode surface wave dispersion

Determining the thickness of Europa's outer ice shell is a key factor for understanding Europa's internal dynamics, evolution, and potential habitability. As such, one of the primary goals of any future lander mission to Europa would be to constrain the thickness of the ice shell and confirm the presence of a global subsurface ocean. Tidally induced ice fracturing events provide a natural source of seismic energy to illuminate the subsurface, thus a seismic instrument onboard a future lander mission could provide a promising means to probe ice shell thickness. A variety of seismic techniques could be used to constrain Europa's interior structure and dynamics, including body wave, surface wave, and normal mode seismology. Here, we use numerical simulations of seismic wave propagation on Europa in order to investigate the potential of using long period dispersion measurements of Rayleigh and flexural waves to constrain the ice shell thickness. Since the sensitivity kernels of group velocity dispersion measurements depend strongly on the structure of the ice shell, inverting for ice shell thickness is a non-linear problem.To address this, we use either a grid search or Markov chain Monte Carlo inversion approach, and test the method on a variety of plausible models of Europa's interior. Additionally, we demonstrate our approach in a “blind” inversion using the 1 week long synthetic catalogs of Europa's seismicity from Panning et al. (2018). We find that under most scenarios, group velocity dispersion measurements between periods of 25–250 s can constrain Europa's ice shell thickness to within several km uncertainty, although the method becomes increasingly inaccurate for thicker ice shells and at large epicentral distances. Our results, which suggest that surface waves from naturally occurring ice fracturing events on Europa can be used to help determine ice shell thickness, may help set instrument requirements for spaceflight capable seismometers aimed at exploring icy ocean worlds.

Lifetime risks of hip fracture in patients with type 2 diabetic: Taiwan Diabetes Study.

The lifetime risks of hip fracture have not been reported across the age spectrum in male adults and female adults with type 2 diabetes. A retrospective cohort study was conducted on 25275 men and 27953 women with type 2 diabetes aged 30-100 years old and participated in the National Diabetes Case Management Program in 2002-2004 in Taiwan. Sociodemographic factors, biomarkers, and comorbidity at the baseline and hip fracture events were analyzed with Cox proportional hazards regression models with age as the time scale. Significant differences in the lifetime risks of hip fracture were observed between men and women with type 2 diabetes. The cumulative lifetime incidences (%) of hip fracture at 50, 60, 65, 70, 75, 80, and 85 years old for men were 0.11, 0.40, 0.84, 1.84, 3.82, 8.53, and 16.72, respectively. The corresponding lifetime incidences (%) for women at 50, 60, 65, 70, 75, 80, and 85 years old were 0.05, 0.50, 1.36, 3.89, 9.56, 21.19, and 35.45, respectively. With competing risks, the significant multivariate-adjusted hazard ratio of developing hip fracture included smoking, alcohol drinking, duration of diabetes, type of oral hypoglycemic drugs use (no medication, sulfonylurea only, thiazolidinediones (TZD) only or TZD plus others, other single or multiple oral agents, insulin use, insulin plus oral hypoglycemic drug use), loop diuretics use, use of corticosteroids, normal weight or underweight, hyperlipidemia, and chronic obstructive pulmonary disease. The gender differences in lifetime hip fracture risk were significant. Thiazolidinediones and insulin use are factors with the greater magnitude of strength of association among those significantly associated with hip fracture.

Experimental Research on Brittleness and Rockburst Proneness of Three Kinds of Hard Rocks under Uniaxial Compression

Rockburst is a highly destructive geological disaster caused by excavation and unloading of hard and brittle rock mass under high geostress environment. Quantitative evaluation of rock brittleness and rockburst proneness is one of the important tasks in potential rockburst assessment. In this study, uniaxial compression and acoustic emission tests were carried out for basalt, granite, and marble, and their brittleness and rockburst proneness were quantitatively evaluated. The acoustic emission evolution characteristics of the three rocks during uniaxial compression were analyzed, and the differences of fracture mechanism of the three rocks were compared. The results show that (1) based on the brittleness evaluation index, basalt is the most brittle rock, followed by granite, and marble is the weakest; (2) based on the rockburst proneness evaluation index, combined with the macroscopic failure phenomenon and morphology of the samples, the rockburst proneness of basalt is the strongest, followed by granite, and marble is the weakest; (3) there exists a positive correlation between rockburst proneness and brittleness, and the fitting results show that they are approximately exponential; and (4) brittleness has an important influence on the rock fracture mechanism. Unlike marble, basalt and granite with strong brittleness continuously present high-energy acoustic emission signals in the stage of unstable crack propagation, and large-scale fracture events continue to occur; from the calculation results of the acoustic emission b value, the stronger the brittleness of rock, the larger the proportion of large-scale fracture events in the failure process.

Role of anisotropy in the ballistic response of rolled magnesium

Rolled magnesium alloys exhibit pronounced tension-compression asymmetry as well as anisotropy in yield and strain-hardening behavior. Although differences in the mechanical response are reasonably well-understood, it is not clear to what extent anisotropy alters the deformation and failure of plates subjected to ballistic loading conditions. In this work, the role of texture and anisotropy in the ballistic response is investigated using a combined experimental–computational approach. Sphere impact experiments are performed on rolled magnesium plates cut from orientations that exhibit differing mechanical responses. The complex failure process is characterized by in situ diagnostics, including ultra-high-speed Digital Image Correlation and Photonic Doppler Velocimetry, and compared with simulations performed on polycrystalline aggregates using a polycrystal plasticity model for hcp metals. The anisotropic deformation behavior arises from deformation mechanisms with disparate strength and strain hardening behavior, which is well captured in the model. The occurrence of low-strength extension twinning is shown to govern the initial anisotropic deformation and bulging of the plate. When compared with post-mortem 3D X-ray microscopy, regions that experience intense basal slip are shown to be sites for damage initiation that leads to eventual fracture. The combination of experiments and simulations suggest that at low to intermediate ballistic loading rates, material orientation plays a crucial role in dictating eventual fracture and failure in strongly anisotropic metals such as in rolled magnesium alloys.

A territory-wide assessment of the incidence of persistent hypoparathyroidism after elective thyroid surgery and its impact on new fracture risk over time

BackgroundAlthough persistent (≥6 months) postoperative hypoparathyroidism is often believed to be rare after elective total thyroidectomy, we hypothesized a higher incidence in the community and that patients with persistent postoperative hypoparathyroidism may have a higher fracture risk. A population-based analysis was performed using an electronic health database to address these issues. MethodsAll elective total thyroidectomies performed in 14 major hospitals across the territory over 20 years were analyzed. Persistent postoperative hypoparathyroidism was defined by the requirement of oral calcium and vitamin D shortly postoperatively and continued for ≥6 months. Those with albumin-corrected calcium <1.90 mmol/L on ≥1 occasion beyond 1 year postoperation were considered suboptimally controlled. Patients were followed until an index fracture, death, or the time of analysis, whichever was earlier. Multivariable Cox regression analysis was used to identify clinical predictors for fractures. ResultsAmong 4,123 eligible patients, 460 patients (11.2%) had persistent postoperative hypoparathyroidism. Over a median of 10.3 years, 126 patients suffered from a new fracture (2.77 per 1,000 person-years). There was no difference in fracture events between patients with and without persistent postoperative hypoparathyroidism (P = .761). Subgroup analyses according to the adequacy of persistent postoperative hypoparathyroidism control did not reveal significant differences in fracture events. Age, female, history of fall, and diabetes independently predicted post-thyroidectomy fractures. ConclusionPersistent postoperative hypoparathyroidism appeared to be a more common complication in the community after elective total thyroidectomy than previously thought. We did not observe a significant difference in fracture risk between patients with and without persistent postoperative hypoparathyroidism. The impact of persistent postoperative hypoparathyroidism control on fracture risk remained to be determined.

MO944BONE DISEASE AFTER KIDNEY TRANSPLANTATION - (SUBTOTAL) PARATHYROIDECTOMY REDUCES FRACTURE RISK

Abstract Background and Aims Kidney transplant recipients can be considered as high-risk collective for pathological fractures, since diverse risk factors leading to mineral bone disorder (MBD) and osteoporosis accumulate in this setting. (Subtotal) parathyroidectomy (PTX) is indicated for ESRD patients with secondary hyperparathyroidism (sHPT) who do not respond to drug therapy adequately. This study aims to identify influencable factors that are associated with pathological fractures and bone disease in KTX recipients. Method We conducted a retrospective study involving 722 adult patients with a total of 4686 patient-years who were transplanted at our center between January 2007 and June 2015. The clinical patient data was extracted from the patients’ electronic files. Different laboratory and clinical parameters for mineral bone disorder and osteoporosis including medication were evaluated. As primary endpoint we chose fracture events that were not related to malignancies or adequate trauma. Results 47 (6,5%) of the patients suffered from pathologic fracture events during the follow-up period. 124 of the patients (17.2%) underwent PTX. In 112 of these patients (90.3%), PTX was performed prior to kidney transplantation (KTx), in 12 patients PTX took place after KTx. Median time for PTX in relation to KTx was 3.7 years prior to KTx (IQR 5.43). Only 1 (2,2%) of the patients with fracture events has received PTX beforehand compared to 124 (19,2%) of the patients without fractures. Adjusted for the well-known fracture risk factors for mineral bone disease and osteoporosis which include female sex, age and dialysis vintage, PTX remains a significant protective factor against fractures after KTx in multivariable Cox regression analysis (HR 0.124, p=0.041) and in Kaplan-Meier analysis (Figure 1). Serum calcium levels were significantly lower in patients after PTX (p&amp;lt;0.001). Active Vitamin D was applicated in patients after PTX more frequently (40.0% vs. 22.7%, p&amp;lt;0.001) Conclusion Our study reveals PTX as a protective factor regarding pathological fractures after KTx. As these patients show lower serum calcium levels, one explanation for this finding could be a more generous supplementation of these patients with active vitamin D, which is known to increase bone mineral density and to reduce fracture risk. Therefore, considering that hypoprathyroidism following PTX after KTx and low plasma-PTH levels correlate with significant decrease of renal function, patients on conservative sHPT therapy should be treated with active vitamin D preparations more generously and special attention should be paid on bone metabolism.

Fracture characteristics by age, sex, and ambulatory status among individuals with cerebral palsy: a descriptive study

Purpose To evaluate clinically relevant fracture characteristics by age, sex, and ambulatory status among individuals with cerebral palsy. Methods Fracture location, energy of fracture, and activities that lead to a fracture were assessed among a clinic-based sample of children (0–17 years; n = 57) and adults (18–70 years; n = 58) with cerebral palsy that sustained a fracture by sex and gross motor function classification system (GMFCS) I–III vs. IV/V. Results Proportion of fractures that were low-energy was 67–99% for children and 69–84% for adults. ∼2/3rds of fractures were at the lower extremities, with the distal femur being the most common site for children (44%) and the foot/ankle for adults (40%); however, there were age, sex, and ambulatory effects, such that 43% of adults GMFCS IV/V and 32% of women had a distal femur fracture. GMFCS I–III were more likely to fracture from functionally complex activities, while GMFCS IV/V were more likely to fracture from wheelchair/transfers/limb-stuck and incidental findings. Conclusions The majority of fractures were low-energy and occurred in the lower extremities, with effects by age, sex, and GMFCS. Activities that led to a fracture also differed by age and GMFCS, which can be used to design fracture prevention interventions in addition to bolstering skeletal mass and architecture. Implications for rehabilitation Skeletal fragility is a major problem for individuals with cerebral palsy (CP) across the lifespan leading to an increased risk of fragility fractures. Rehabilitation is a prime clinical intervention to prevent fractures from occurring and improving post-fracture healing and function; yet, effective rehabilitation interventions require knowledge of fracture characteristics, such as where fractures are occurring and the activities that lead to the fracture event specific to individuals with CP. Using a clinic-based sample of 0–70 year olds with CP, we describe salient fracture characteristics based on age, sex, and ambulatory status to enhance translation into clinical and rehabilitation practice.

Effects of Myo-inositol Hexaphosphate (SNF472) on Bone Mineral Density in Patients Receiving Hemodialysis: An Analysis of the Randomized, Placebo-Controlled CaLIPSO Study.

In the CaLIPSO study, intravenous administration of SNF472 (300 or 600 mg) during hemodialysis significantly attenuated progression of coronary artery and aortic valve calcification. SNF472 selectively inhibits formation of hydroxyapatite, the final step in cardiovascular calcification. Because bone mineral is predominantly hydroxyapatite, we assessed changes in bone mineral density in CaLIPSO. Patients with coronary artery calcification at screening (Agatston score of 100-3500 U) were randomized 1:1:1 to receive placebo, 300 mg SNF472, or 600 mg SNF472 as an intravenous infusion during hemodialysis three times weekly for 52 weeks. Dual-energy x-ray absorptiometry (DXA) scans were obtained at baseline (screening) and end of treatment, and between-group changes from baseline were compared using analysis of covariance. Among 274 randomized patients, 202 had evaluable DXA scans at baseline and postrandomization (the DXA-modified intention-to-treat population). Mean (95% confidence interval) changes in total-hip bone mineral density from baseline to week 52 were -1.5% (-2.7% to -0.3%), -1.5% (-2.7% to -0.4%), and -2.5% (-3.8% to -1.2%) in the placebo, 300 mg SNF472, and 600 mg SNF472 groups, respectively. Mean (95% confidence interval) changes in femoral-neck bone mineral density from baseline to week 52 were -0.3% (-1.6% to 1.0%), -1.0% (-2.3% to 0.2%), and -2.6% (-4.0% to -1.3%), respectively. Regression analyses showed no correlation between change in coronary artery calcium volume and change in bone mineral density at either location. Changes in serum alkaline phosphatase, calcium, magnesium, phosphate, and intact parathyroid hormone levels were similar across treatment groups. Clinical fracture events were reported for four of 90, three of 92, and six of 91 patients in the placebo, 300 mg SNF472, and 600 mg SNF472 groups, respectively. Bone mineral density decreased modestly in all groups over 1 year. In the 600 mg SNF472 group, the reduction appeared more pronounced. Reported fractures were infrequent in all groups. Effect of SNF472 on Progression of Cardiovascular Calcification in End-Stage-Renal-Disease (ESRD) Patients on Hemodialysis (HD), NCT02966028.

Risk Factors for Fracture Events in Maintenance Hemodialysis Patients

Objective: To explore risk factors for fracture events in maintenance hemodialysis patients. Methods: The study population was obtained from the hospital in patient database in China. There were 654 eligible patients with hemodialysis from 2018 – 2020. Other patient-related variables collected include gender, age, history of hypertension, history of diabetes mellitus, dialysis age, active vitamin D, hemoglobin, serum albumin, total cholesterol, triglyceride, serum corrected calcium. The primary outcome was any factors of fracture. Patients were followed until complete treatment or death. Besides, we performed subgroup analyses and used generalized linear models to assess interaction effects in logistic regressions. To clarify the relationship between fracture and risk factors, logistic regression was used. Result: By comparing non-fracture group and fracture group, we found that some factors were significantly difference, including gender, age, active vitamin D, and albumin (p = 0.001, p = 0.001, p < 0.001, p < 0.001). base on multivariate Logistic regression analysis of fracture occurrence in hemodialysis patients, older age, female, and low albumin were independent risk factors for fracture (p < 0.05). Also, the use of active vitamin D is a protective factor for fractures (p < 0.05). Conclusion: the risk factors for fracture events in maintenance hemodialysis patients included older age, female, low albumin, and active vitamin D.

Risk of non-vertebral fractures in men with type 2 diabetes: A systematic review and meta-analysis of cohort studies.

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder. Research regarding the risk of non-vertebral fractures in men, especially in elderly men with T2DM, has not been a priority. T2DM is not a known independent risk factor for low-energy fractures in patients. We aimed to explore the relationship between men (especially older men) with T2DM and the risk of non-vertebral fractures and the reasons for the sex differences. The PubMed, MEDLINE, and Cochrane Library databases were searched for articles on T2DM and fracture risk. A meta-analysis, including heterogeneity testing, publication bias analysis, and subgroup analysis of the included studies, was performed using STATA software. Sixteen studies involving 1,758,225 participants, 59,909 non-vertebral fracture events, and 6430 vertebral fracture events were included in this research. The adjusted relative risk of T2DM and non-vertebral fracture in men was 1.20 (95% confidence interval [CI] 1.09-1.31), implying that men with T2DM have a slightly increased risk of non-vertebral fracture. Male patients with T2DM have a slightly increased risk of non-vertebral fractures. Due to the differences in bone strength, sex steroid hormone levels, bone quality and muscle strength and balance, men with type 2 diabetes have a lower risk of non-vertebral fractures than women.

Interventional revascularization prior to operative fixation of fractures below the knee. A retrospective case series

AimsThe goal of the current study was to describe the results of an innovative standardized approach to prevent wound complications in patients with PAD sustaining fractures below the knee. Patients and methodsIn this retrospective case series, patients submitted to our institution with fractures below the knee, which were treated with endovascular recanalization of relevant stenosis or occlusions prior to definitive open reduction and fracture fixation between January 2015 and December 2019 were included. ResultsOverall 23 patients (mean age 77 ± 9.8 years) were included in the current case series. In five patients (21.7 %) PAD was previously diagnosed. Endovascular interventions were performed 6.9 ± 2.5 days after fracture event and 2.5 ± 1.3 days prior to definitive surgical fixation of the lower limb fracture. After intervention 2 patients had one vessel, 10 patients two vessels and 11 patients three vessels for arterial perfusion of the lower limb. No interventional- radiology procedure related complications were observed. In this case series only two wound infections (8.7 %) occurred. ConclusionEndovascular intervention prior to surgical fixation resulted in a low complication rate after surgical fixation of fractures below the knee in patients with PAD. These results emphasize the crucial role of limb perfusion for adequate wound healing in lower limb fractures. Therefore, examination of limb perfusion should be an integral part of preoperative preparation of patients at high risk for PAD presenting with fractures below the knee. Endovascular recanalization seems to be an appropriate method to prevent wound complications.

Study on impact fracture behavior of G18CrMo2-6 steel after tempering

The evolution of microstructure of low alloy CrMo steel has a great influence on the mechanical properties. Three different tempering heat treatment conditions were made on the material, and the influence of the microstructure on the impact toughness under different test temperatures was studied. The type, morphology, size and distribution of the second phase will evolve with the change of tempering temperature and time. Impact energy of all samples increases gradually from the lower shelf to upper shelf with the testing temperature increasing. In the lower shelf, the fracture is controlled by the crack nucleation. In the ductile-to-brittle transition temperature (DBTT) range, the fracture is determined by the size of the initial crack initiating on the second phase. In the upper shelf, the cleavage fracture is controlled by the propagation of the carbide crack into continuous grains, and the critical event for fracture is the plasticity of the matrix. The scattering of impact energy in DBTT range is caused by the uneven distribution and size of the brittle second phase.

A review of phase-field models, fundamentals and their applications to composite laminates

Innovations of advanced materials have been at the core of most engineering technologies, devices and systems. Composite laminates in particular have been extensively employed in many major and advanced industries including aircraft, maritime transport, and automobiles. Failure in composite structures is critical and often complicated, and that is the consequence of the evolution of and interactions among the constitutive fracture events (e.g., matrix cracking, fibre/matrix debonding, delamination, fibre breakage, fibre kinking). Accurate prediction of progressive failure in composite laminates is crucial for the development and design of most lightweight components and structures. This paper, for the first time, outlines a critical review on the developments and recent applications of regularized phase field models for failure problems in composite laminates and structures. Fundamentals of the phase field models are introduced and the developments of the regularized model from different aspects for the modeling are reviewed. Phase field models as well as the modeling strategies from different levels of idealization, i.e., microscopic, mesoscopic and macroscopic length scales are presented. The realization of existing widely used models such as cohesive zone model, plasticity, and damage initiation criterion and energy decomposition into the phase field model is also addressed. Typical applications of the phase field models in composite laminate modeling are discussed.