Fracture Events Research Articles

Confocal Microscopy Visualizes Particle–Crack Interactions in Epoxy Composites with Optical Force Probe-Cross-Linked Rubber Particles

Brittle fracture often compromises the durability of glassy polymers. This can be mitigated by reinforcing the matrix with a filler, activating a range of toughening mechanisms. Therefore, it is desirable to better understand the mechanical response of polymer composites, but a direct visualization of the mechanical fate of second-phase inclusions upon material fracture was previously unavailable. Here, rubbery poly(hexyl acrylate) particles, cross-linked with an optical force probe (OFP), are dispersed within an epoxy matrix, the material is fractured, and particle–crack interactions are visualized with confocal laser scanning microscopy. The dual-fluorescence character of the OFPs allows the differentiation between particles that remain intact and those that are stressed beyond bond scission upon interaction with a propagating crack. The localized activation of OFPs reveals stress gradients within the particles and crack direction pathways, hence providing a new layer of information over fracture events in polymer composites.

The Influence of Parathyroidectomy on Osteoporotic Fractures in Kidney Transplant Recipients: Results from a Retrospective Single-Center Trial.

Kidney transplant (KTx) recipients are a high-risk population for osteoporotic fractures. We herein aim to identify the role of pre-transplant parathyroidectomy (PTX) and other modifiable factors associated with osteoporotic fractures in KTx recipients. We conducted a retrospective study involving 711 adult patients (4608 patient-years) who were transplanted at our center between January 2007 and June 2015. Clinical data were extracted from patients’ electronic medical records. Different laboratory and clinical parameters for mineral bone disease (MBD) and osteoporosis, including medication, were evaluated. We chose fracture events unrelated to malignancies or adequate trauma as the primary endpoint. Osteoporotic fractures occurred in 47 (6.6%) patients (median 36.7 months, IQR 45.9) after KTx (fracture incidence of 10 per 1000 person-years). Prior to KTx, subtotal PTX was performed in 116 patients (16.3%, median time 4.2 years before KTx, IQR 5.0). Of the patients with fracture (n = 47), only one (2.2%) patient had previously undergone PTX. After adjusting for the known fracture risk factors MBD and osteoporosis, PTX remained a protective factor against fractures (HR 0.134, CI 0.018–0.991, p = 0.049). We observed a reduced risk for pathological fractures in KTx patients who underwent PTX, independent from elevated parathyroid hormone at the time of KTx or afterwards.

Intervention with the Bone-Associated Tumor Vicious Cycle through Dual-Protein Therapeutics for Treatment of Skeletal-Related Events and Bone Metastases.

Bone metastasis is a common metastasis site such as lung cancer, prostate cancer, and other malignant tumors. The occurrence of bone metastases of lung cancer is often accompanied by bone loss, fracture, and other skeletal-related events (SREs) caused by tumor proliferation and osteoclast activation. Furthermore, along with the differentiation and maturation of osteoclasts in the bone microenvironment, it will further promote the occurrence and development of bone metastasis. Protein drugs are one of the most promising therapeutic pharmaceuticals, but in vivo delivery of protein therapeutics still confronts great challenges. In order to more effectively conquer bone metastases and alleviate SREs, herein, we constructed biomineralized metal-organic framework (MOF) nanoparticles carrying protein toxins with both bone-seeking and CD44-receptor-targeting abilities. More importantly, through combination with Receptor Activator of Nuclear Factor-κ B Ligand (RANKL) antibody, in vivo results demonstrated that these two protein agents not only enhanced the detraction effects of protein toxin agents as ribosome-inactivating protein (RIP) on bone metastatic tumor cells but also exhibited synergistic intervention of the crosstalk between bone cells and tumor cells and reduced SREs such as bone loss. Collectively, we expect that this strategy can provide an effective and safe option in regulating bone-tumor microenvironments to overcome bone metastasis and SREs.

A brief note on monotonic and fatigue fracture events investigation of thin-walled tubular austenitic steel specimens via fracture surface topography analysis (FRASTA)

The main objective of this short communication is to show the fracture progression in each loading case and complement knowledge about fracture mechanisms underpinning the tensile and fatigue performance of thin-walled tubes. For this purpose, the fracture surface topography analysis (FRASTA) method was used in the thin-walled tubular austenitic stainless-steel specimens. Two cases were analyzed: monotonic tension, and uniaxial fully-reversed fatigue. Furthermore, the fractures topographies were quantified through the profiles over their entire surfaces with the support of an optical confocal measurement system. The results showed the usefulness of the FRASTA method in identifying characteristic zones in the cracking process for the analyzed cases and motivates its development for other materials and complex loading cases.

Influencing Factors in Acoustic Emission Detection: A Literature Review Focusing on Grain Angle and High/Low Tree Ring Density of Scots Pine

Among non-destructive testing (NDT) techniques applied to structural health monitoring in existing timber structures, ranging from visual inspection to more sophisticated analysis, acoustic emission (AE) is currently seldomly used to detect mechanical stresses in wooden building assets. This paper presents the results from a systematic literature review on AE NDT applied to monitor micro and macro fracture events in softwood, specifically Scots pine. This survey particularly investigates its application with respect to the tree rings density and grain angle inspection, as influencing factors well correlated with physical and mechanical characteristics of wood. The literature review was performed in a three-step process defined by the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) flow diagram, leading to the selection of 31 documents from different abstract and citation databases (Scopus, Web of Science and Google Scholar). The outcomes have highlighted how laboratory experiments, including several types of tests (tensile, cutting, compressive, etc.), were conducted in most cases, while a very limited number of studies investigated on in situ monitoring. In addition, theoretical approaches were often explored in parallel with the experimental one. It emerges that—for tree ring density studies—a multi-technique approach, which may include microscopic observations, could be more informative. Indeed, although not widely investigated, high/low tree ring density and grain angle were found as influencing factors on the AE parameters detected by the sensors, during condition and structural health monitoring experiments.

Association of clinical and social factors with risk of fracture in children with atopic dermatitis.

Children with atopic dermatitis (AD) have multiple risk factors for accidental fractures, injuries that can lead to significant morbidity and mortality. However, little is known about the factors that mediate the relationship between AD and fracture in children. Our purpose was to examine the association of AD with fracture and to identify potential mediating factors. This retrospective cohort study examined children with and without AD from a longitudinal matched cohort database of 353,040 children registered in the national health insurance service and participated in the national health-screening program of Korea. We defined AD using medical claims and medication prescription records. We investigated accidental fracture events between the index date and the end of follow-up in a propensity score-matched cohort. Pre-specified subgroup analyses considered fractures in four different regions of the body. The mediating effects of 10 possible clinical factors (including the use of antihistamines and systemic corticosteroids) and social factors (including nutritional status and parental safety awareness) were determined. There were 145,704 participating children, 20% with AD and 49% girls. Fractures occurred in 6,652 of the children with AD (23%, mean age: 64.6±29.2months) and in 24,698 of the control group (21%, mean age 65.0±28.9months). Children with AD had an 8% greater risk of fracture events overall (adjusted relative risk [aRR]: 1.08, 95% CI: 1.05-1.10). In subgroup analysis, AD was related to increased rates of skull and facial bone fracture (aRR: 1.09, 95% CI: 1.04-1.14), for trunk including vertebrae (aRR: 1.58, 95% CI: 1.22- 2.05), and for distal limbs (aRR: 1.11, 95% CI: 1.07-1.15). However, the relationship with proximal limb fracture was insignificant. Duration of systemic corticosteroid prescription was the largest mediating factor, followed by duration of antihistamine prescription, and infant feeding practices. In particular, the duration of systemic corticosteroid prescription was significantly associated with fracture events (incidence: 20.1% at the 25th percentile and 23.6% at the 75th percentile; difference: 3.4% [95% CI: 2.8-4.0%]). Children with AD were related to increased fracture events. The key factors with mediating effects were systemic use of corticosteroid and antihistamine. Infant feeding practices had weaker mediating effects.

Associations of variability in body weight and glucose levels with the risk of hip fracture in people with diabetes

BackgroundDiabetes is associated with a high risk of fragility fracture. However, there are controversies regarding the effect of fluctuations in metabolic parameters on the risk of fracture. We aimed to investigate the associations of body weight or glucose variability or their combination with the risk of hip fracture in people with diabetes. MethodsA population-based cohort study with 480,539 subjects over 40 years who had undergone three or more health examinations was performed. The degree of variability was evaluated using variability independent of the mean (VIM, 100 × standard deviation / meanbeta), coefficient of variation (CV), and average real variability (ARV, average of the absolute differences between consecutive values). High variability was defined as having values in the highest quartile. Cox proportional hazards models were used to estimate the risk of hip fracture. ResultsThere were 2834 hip fracture events (0.59%) during the mean follow-up of 8.1 years. After multivariable adjustment for age, sex, alcohol consumption, smoking, regular exercise, income, glucose, body mass index, hemoglobin, estimated glomerular filtration rate, diabetes duration, diabetes treatment with multiple agents, and osteoporosis, the HRs (95% CI) of hip fracture were 1.36 (1.24–1.50) and 1.29 (1.16–1.43) for high body weight VIM and high glucose VIM, respectively. The HR (95% CI) of both high VIM group was 1.63 (1.44–1.83), suggesting an additive effect of variabilities in body weight and glucose. The results were consistent when using CV and ARV and in various sensitivity analyses. ConclusionsHigh variability in body weight and glucose levels is associated with an increased incidence rate and risk of hip fracture in people with diabetes.

Efficacy and safety of bisphosphonates on childhood osteoporosis secondary to chronic illness or its treatment: a meta-analysis.

Background:Bisphosphonates are a type of medication that prevents the loss of bone density. Secondary childhood osteoporosis reduces bone strength and results in an increased risk of fragility fracture. This meta-analysis aims to explore the efficacy and safety of bisphosphonates on secondary childhood osteoporosis.Methods:We performed a systematic search of PubMed, Cochrane library, and Web of Science databases up to 31 July 2022 to screen for random clinical trials (RCTs) on bisphosphonate treatment for childhood secondary osteoporosis. Data from selected studies, mainly changes in lumbar spine (LS) bone mineral density (BMD), changes in LS BMD Z-scores, fracture events, and adverse events (AEs), were extracted and analyzed.Results:Nine RCTs (n = 429 in total) were included in our meta-analysis. The meta-analysis indicated that bisphosphonates improved the changes in LS BMD [mean difference (MD) = 0.04, 95% confidence intervals (CIs) = 0.01–0.07, p < 0.01] and LS BMD Z-scores [MD = 0.52, 95% CI = 0.23–0.81, p < 0.01]. Use of bisphosphonates did not increase the risk of AEs [odds ratio (OR) = 1.61, 95% CI = 0.87–2.99, p = 0.13]. Subgroup analysis showed that routes of administration, but not causes of secondary osteoporosis, might influence the efficacy of bisphosphonates. IV bisphosphonates close to significantly improved the incidence of fracture (OR = 0.34, 95% CI: 0.11–1.08, p = 0.07).Conclusions:The use of bisphosphonates improves LS BMD without increasing AE rates, which supports the clinical use of bisphosphonates in secondary childhood osteoporosis. Further large RCTs are still warranted, especially for their long-term effects on fracture rates.

Variações sazonais na incidência de fraturas do fêmur no estado do Rio Grande do Sul, sul do Brasil

Abstract Introduction Femoral fractures are a major cause of morbidity and mortality, mainly among older people. Objective To examine the effect of seasonality on hospitalizations due to femur fracture among people residing in the Rio Grande do Sul state, southern Brazil, from 2008 to 2019. Methods Ecological study based on secondary data from the SUS Hospital Information System (SIH/SUS). A total of 74,374 reports of hospital admissions was considered. The generalized additive model (GAM) approach was employed to assess the seasonality of the time series, with stratification by sex and age groups and considering the monthly average number of events of femoral fractures per day as a dependent variable. Results A considerably higher incidence of femoral fractures in women aged 70 years or more was described. Among people aged less than 50 years, there is not an apparent seasonal effect. Men aged 70 years or older and women aged 50 years or older have a higher frequency of hospitalizations due to femur fractures in the colder months. Conclusion Among older people, more femoral fractures occurred during the winter compared to summer. This supports findings from other studies, although reasons for this seasonal variation are uncertain. The knowledge of these seasonal variations can help to plan the health care in the public health system.

Ductile fracture of DX51D material sheet metal panel produced by hemming process

In this study, the fracture problem occurring in the bending areas of the sheet metal panel produced by the hemming process was investigated by numerical method. The part is produced with cold-rolled continuous galvanized DX51D grade material which is commonly used. As is known, there is no upper yield stress limit value for this material according to EN 10346:2015. In addition to this, for this steel grade when the yield and tensile stresses increase, ductility capability decreases significantly. Also, when the metal forming simulations are done with only uniaxial tensile test data of material, unexpected failures could arise for the hemming process. Therefore, the type of stress that occurred on the material by the process applied in the production should be carefully examined and material data should be extracted for dominant stress types. The use of this material without limiting mechanical properties can cause unexpected cracks and tears, especially in processes with high plastic deformation such as hemming. In order to observe the fracture occurrence, the stress triaxiality factor of the material was examined and the dominant stress triaxiality value with strain to fracture path in the hemming process was determined with finite element analysis. Due to their similar mechanical properties, being used as raw material for DX51D and having ductile fracture parameters available in the literature, hot-rolled S235JR and S275JR materials are chosen to observe fracture event in numerical analysis. Equivalent strain to fracture-stress triaxiality and lode angle curves were used with the Hosford-Coulomb ductile fracture model to examine the effects on the hemming process. All numerical calculations were performed in the commercial Altair RADIOSS software that can perform high nonlinearity calculations. Finally, a performance comparison was made between materials and the experiment for the hemming process.

Structural Assessment of the European DEMO Water-Cooled Lithium Lead Breeding Blanket Central Outboard Segment Under Remote Maintenance Loading Conditions

Within the framework of the European research activities devoted to design the DEMO breeding blanket (BB), the Water-Cooled Lithium-Lead (WCLL) BB concept is one of the candidates currently assessed in EU. One of the main issues connected to its design is represented by the remote maintenance (RM) operations. In particular, previous thermo-mechanical analysis highlighted a Ductile to Brittle Transition Temperature (DBTT) shift above the room temperature within the WCLL central outboard (COB) segment during normal operation. This may pose problems during the RM operations foreseen in the BB replacement phase. Indeed, within those WCLL COB segment’s regions where the DBTT shifted above the room temperature, the stress level arising during RM operations may be able to promote crack growth and migration resulting in a fragile fracture event. Then, in this work, the structural assessment of the DEMO WCLL COB segment under RM scenarios is performed, in order to provide the fracture mechanics analysis with the necessary input in terms of stress spatial distribution and to understand if the deformation occurring during RM can be accommodated by the available space reservation. Several potential RM scenarios have been considered, taking into account also the potential occurrence of a seismic event or the necessity to remove the WCLL COB segment with the liquid breeder not drained. The study has been performed adopting a numerical approach based on the Finite Element Method and adopting the quoted Abaqus code. The obtained results are quite encouraging and will allow, in the follow up, the refinement of the RM plan foreseen for the WCLL BB.

Evolution of fracture networks and connectivity during fault–bend folding: Insights from the Sinon Anticline in the southwestern Hongseong–Imjingang Belt, Korea

Crustal shortening in an elastico-frictional regime is mainly accommodated by contractional fault–fold systems with fracture networks. According to recent research, fracture networks in fold–thrust belts express complex internal strain states in response to thrusting and related folding. Furthermore, their connectivity and fluid flow characteristics likely depend on the structural positions and mechanical stratigraphy that control heterogeneous deformation processes. This study provides characteristics of fold-related fracture networks in the Sinon Anticline, which was formed by fault–bend folding in the southwestern Hongseong–Imjingang Belt, Korea. The fracture networks in the metamorphosed turbidites characterized by interbedded competent metasandstone layers and relatively thin incompetent schist layers have evolved through pre-, syn-, and post-folding fracturing events. Their complexity reflects the spatiotemporal variation in the strain pattern related to early layer-parallel shortening and subsequent fault–bend folding. Based on insights from detailed mapping and topological analysis of the fracture network, we conclude that strain partitioning that occurs during flexural folding results in a superposed tangential longitudinal strain expressed by fractures with a high (hydraulic) connectivity in the hinge zones. Strain partitioning is caused by flexural interlayer slip along incompetent schist layers in the fold limbs. Bed-parallel slip localization zones probably have low porosity and permeability and may act as barriers to fluid migration across beds. We suggest that heterogeneous vertical axis rotation, which occurred as the system's hanging wall slid over the footwall ramp, increased the complexity of fracture networks within the Sinon Anticline. Our findings indicate that the evolution, connectivity, and fluid flow properties of fracture networks can be characterized through careful interpretation of folding mechanisms and related strain states during formation of fault–bend fold systems.

A probabilistic model for fracture events of Petermann ice islands under the influence of atmospheric and oceanic conditions

Abstract. Four calving events of Petermann Glacier happened in 2008, 2010, 2011, and 2012, which resulted in the drift and deterioration of numerous ice islands, some reaching as far as offshore Newfoundland. The presence of these ice islands in the eastern Canadian Arctic increases the risk of interaction with offshore operations and shipping activities. This study uses the recently developed Canadian Ice Island Drift, Deterioration and Detection database to investigate the fracture events that these ice islands experienced, and it presents a probabilistic model for the conditional occurrence of such events by analyzing the atmospheric and oceanic conditions that drive the causes behind the ice island fracture events. Variables representing the atmospheric and oceanic conditions that the ice islands were subjected to are extracted from reanalysis datasets and then interpolated to evaluate their distributions for both fracture and non-fracture events. The probability of fracture event occurrence for different combinations of input variable conditions is quantified using Bayes' theorem. Out of the seven variables analyzed in this study, water temperature and ocean current speed are identified as the most and least important contributors, respectively, to the fracture events of the Petermann ice islands. It is also revealed that the ice island fracture probability increases to 75 % as the ice islands encounter extreme (very high) atmospheric and oceanic conditions. A validation scheme is presented using the cross-validation approach and Pareto principle, and an average error of 13 %–39 % is reported in the fracture probability estimations. The presented probabilistic model has a predictive capability for future fracture events of ice islands and could be of particular interest to offshore and marine ice and risk management in the eastern Canadian Arctic. Future research, however, is necessary for model training and testing to further validate this ice island fracture model.

Association of co-prescribing of opioid and benzodiazepine substitutes with incident falls and fractures among older adults: a cohort study

ObjectiveExamine the association between the co-prescribing of opioids, benzodiazepines, gabapentinoids (pregabalin and gabapentin) and selective serotonin reuptake inhibitors/serotonin and norepinephrine reuptake inhibitors (SSRI/SNRIs) in different combinations and the risk of...

A multi-channel verification index to improve distinguish accuracy of target signals in rock burst monitoring of heading face

Microseismic (MS) or acoustic emission (AE) system has been used for rock burst warning in heading face for a period of time, but the main problem focus on how to accurately obtain the target coal fracture event (CFE) or how to remove interference signals. In the study, the location and characteristics of CFEs in a heading face are determined, and the commonly STA/LTA (short-term to long-term average) method is used to distinguish CFEs from interference signals, results show that STA/LTA method cannot substantially remove the large number of interference signals in heading face. Based on this fact, a multi-channel verification index is proposed to pick up CFEs in heading face, the index can preliminarily provide a significant accuracy rate for CFEs and reflect the abnormal stress field of heading face, which lays an important reference for monitoring and warning index selection of rock burst in heading face.

Activation of Mechanophores in a Thermoset Matrix by Instrumented Scratch.

Scratches in polymer coatings and barrier layers negatively impact optical properties (haze, light transmission, etc.), initiate routes of degradation or corrosion (moisture permeability), and nucleate delamination of the coating. Detecting scratches in coatings on advanced materials systems is an important component of structural health monitoring but can be difficult if the defects are too small to be detected by the naked eye. The primary focus of the present work is to investigate scratch damage using fluorescence lifetime imaging microscopy (FLIM) and mechanical activation of a mechanophore (MP)-containing transparent epoxy coating. The approach utilizes a Berkovich tip to scratch MP-epoxy coatings under a linearly increasing normal load. The goal is to utilize the fluorescent behavior of activated MPs to enable the detection of microscale scratches and molecular scale changes in polymeric systems. Taking advantage of the amine functionality present in a polyetheramine/bisphenol A epoxy network, a modified rhodamine dye is covalently bonded into a transparent, thermoset polymer network. Following instrumented scratch application, subsequent fluorescence imaging of the scratched MP-epoxy reveals the extent of fluorescence activation induced by the mechanical deformation. In this work, the rhodamine-based mechanophore is used to identify both ductile and fracture-dominated processes during the scratch application. The fluorescence intensity increases linearly with the applied normal load and is sensitive to fracture dominated processes. Fluorescence lifetime and hyperspectral imaging of damage zones provide additional insight into the local (nanoscopic) environment and molecular structure of the MP around the fracture process zone, respectively. The mechanophore/scratch deformation approach allows a fluorescence microscope to probe local yielding and fracture events in a powerful way that enhances the optical characterization of damage zones formed by standard scratch test methods and leads to novel defect detection strategies.

Fatigue resistance of ultra-high-modulus pitch-based carbon fiber/epoxy composites under tensile loading

Pitch-based carbon fiber reinforced epoxy composites are used in specialized applications for their high-modulus and thermal conductivity; however, little data on their fatigue performance are available in the open literature. In this study, fatigue behaviors of ultra-high-modulus pitch-based carbon fiber and standard-modulus polyacrylonitrile (PAN)-based carbon fiber were compared in woven quasi-isotropic epoxy matrix composites subject to uniaxial tension. It was found that the pitch fiber composite possessed higher normalized tensile fatigue strength and that its stress-life ( S-N) curve is less steep. Extrapolation suggests the pitch fiber composite is more fatigue-resistant in higher cycle regimes (specifically, N &gt; 107). Cyclic loading of the pitch fiber composite resulted in minimal matrix damage, and the eventual fractures were localized and fiber-dominated for all stress levels. Cyclic loading of the PAN fiber composites resulted in widespread matrix cracking and delamination. The difference in fatigue behavior is attributed to the different strain levels attained at similar stress levels and the consequent difference in matrix damage development.

Femoral Neck Fractures in HIV-Positive Patients: Analysis of 10 Years Short-Term Post-operative Complications.

Introduction:Aging and effect of antiretroviral therapy on bone mass could increase the risk of femoral neck fractures (FNF) in HIV patient. The aim of this study was specifically to determine whether intracapsular FNF in HIV-positive patients are more prone to short-term post-operative complications than similar fractures occurring in HIV-negative patients.Materials and methods:A group of 25 HIV-positive patients with intracapsular FNF were enrolled and matched to HIV-negative patient with similar fractures according to gender, age, a modified Charlson Comorbidity Index (CCI), fracture classification, surgical treatment and time interval between fracture event and surgery. For each group, length of stay, surgical time, early clinical outcomes and short-term surgical and medical complications were compared to determine the impact on the early outcome.Results:At the time of the fracture occurrence, 56% of HIV-positive patients were on antiretroviral therapy and 12% started with therapy in the perioperative period. At three months follow-up, there were no statistically significant differences between the two study groups in length of stay, Harris hip score and total number of early complications. However, a statistically significant increase in urinary tract infections and longer surgical time using hip sliding screw fixation were seen in the HIV-positive group. The poorest post-operative result was seen in a patient who failed to adequately adhere to the HIV therapy protocol.Conclusions:This study failed to show any statistically significant increase in short-term complications or worse clinical outcomes for intracapsular FNF in HIV-positive patients compared to HIV-negative patients to recommend their treatment in dedicated centres.

Correlation between metabolic syndrome and adverse events after internal fixation of femoral intertrochanteric fracture in the elderly

To explore the effect of metabolic syndrome on 15 days postoperative adverse events of femoral intertrochanteric fractures with internal fixation. From January 2011 to June 2019, 986 elderly patients with intertrochanteric fracture were treated with internal fixation, including 312 males and 674 females, with an average age of(77.71± 7.58) years old. And there were 97 patients with metabolic syndrome and 889 patients without metabolic syndrome. Through the electronic medical record system, the patient's age, gender, fracture type, cause of trauma, body mass index, smoking history, preoperative comorbidities, preoperative bloodtransfusion, operation timing, ASA classification, anesthesia method, internal fixation type, operation duration, and 15 days postoperative adverse events, which include surgical site infection, acute heart failure, acute respiratory failure, pulmonary infection, acute renal failure, DVT, embolism in important organs, urinary tract infection, death, and blood transfusion after surgery were collected. The differences of preoperative and intraoperative baseline datas and 15 days postoperative adverse events between the two groups were compared and analyzed by t text or univariate χ2 test. Adjusted for the preoperative and intraoperative mixed factors with P<0.05, and 15 days postoperative adverse events with P<0.05 were then analyzed by multivariate unconditional Logistic regression analysis to further study the independent effects of metabolic syndrome on 15 days postoperative adverse events. There were statistical differences in age, body mass index, history of cardiac insufficiency, history of COPD, history of renal insufficiency, operation timing, ASA classification, operation duration, surgical site infection, acute heart failure, DVT, urinary tract infection and blood transfusion between two groups (P<0.05). Adjusted for the preoperative and intraoperative mixed factors, multivariate unconditional logistic regression analysis showed that metabolic syndrome could increase the infection rate of the surgical site [OR=3.785, 95%CI (1.086-13.188), P= 0.037], DVT incidence rate[OR=2.265, 95%CI(1.096-4.682), P=0.027], urinary tract infection rate[OR=2.703, 95%CI (1.049-6.963), P=0.0390], and blood transfusion rate [OR=1.811, 95%CI (1.142-2.870), P=0.012]. Elderly patients with intertrochanteric fracture with metabolic syndrome had higher postoperative surgical site infection rate, DVT incidence rate, urinary tract infection rate, and postoperative blood transfusion rate. Therefore, the orthopedic treatment team should give more attentionand optimize the treatment plan during the perioperative period with the cooperation of internal physician and anesthesiologist.

Medical assessment in the field of Social ActVII: pre-existing damage and causality of apophyseal injuries and detachments

The medical assessment of affections of the apophyses frequently presents the assessor with problems in causality testing and estimation of functional impairment. Apophyses are the insertion of tendons and are therefore at the center of an acting parallelogram of forces. They fuse via an apophyseal plate in the second decade of life. Depending on the age there is areduced mechanical load-bearing capacity of the apophyseal plates in the last 1-2years before complete mineralization of the joint. Two types of injury must be distinguished in an expert opinion: apophyseal detachment as aresult of repetitive microtrauma in the event of chronic overload and apophyseal avulsion fracture as an acute injury due to sudden maximum muscle tension. While chronic overload leads to exclusion from insurance cover by the statutory accident insurance, apophyseal avulsion fractures fulfil the necessary requirements for acceptance as an insurance case. The apophyseal avulsion fracture is subject to atime-limited force, which directly leads to damage to health and avulsion of the tibial tuberosity including its tension system. The sudden jerky maximum muscle pull leads to an overload of the tension system and avulsion of the apophysis in cases of an age-related vulnerable apophyseal plate. Once the mineralization is complete, this type of fracture no longer occurs. Osgood-Schlatter disease, an insertion tendinosis of the patellar tendon, occurs in around 20% of all sport-active adolescents but it is questionable whether it can be associated with the acute avulsion fracture. Knowledge of the pathogenesis of affections and injuries of the apophysis can provide the assessor with good foundations for the estimation of a causal association.