Total Fracture Research Articles

[Translated article] Surgical treatment of ipsilateral bifocal tibial fractures: A challenge for the surgeon

IntroductionThe association of ipsilateral tibia fractures has a low incidence, being up to 3.2% of total tibia fractures. Currently there is no gold standard regarding the ideal surgical treatment.The objective of this study is to analyze the surgical treatment and the radiographic and functional results, as well as the associated complication rate of ipsilateral bifocal tibia fractures. Material and methodsRetrospective observational study in our hospital from 2010 to 2022 of 24 patients who underwent bifocal fracture of the ipsilateral tibia. Demographic and surgical data and complications during follow-up were included. ResultsThe 24 patients were classified into Group 1 when they presented a fracture of the plateau and distal tibia (25%), Group 2 with a fracture of the plateau and diaphysis (33%) and Group 3 with a fracture of the diaphysis and distal tibia (42%). Three patients underwent surgery with 1 implant and 21 patients with 2 implants. The average follow-up time in outpatient clinics was 2 and a half years. At one year, 22 patients (92%) had full weight bearing and 2 patients had partial weight bearing (8%) due to the sequelae of the fractures. The average time for consolidation of the diaphysis was 7.75±2 months, with no significant differences observed between Group 2 and Group 3 (p=0.06). The average time for consolidation of the metaphysis was 3.50±1.5 months, with no significant differences observed between Group 1 and Group 2 (p=0.065). Seven patients (30%) had complications during follow-up. ConclusionsBifocal tibia fractures can be treated using a combination of intramedullary nailing and plate osteosynthesis with good long-term results, obtaining an optimal union rate and low complications. In addition, it facilitates the reduction of the fracture, thus facilitating the patient's recovery and obtaining good long-term functional results.

Study on the influence of lamination density and perforation position on fracture height propagation and proppant distribution

In the Bonan block of the Jiyang Depression, the lacustrine shale exhibits various types of organic-rich laminar lithofacies with complex distributions in lamination density and thickness, showing clear cyclic variations vertically over scales of several meters or even centimeters. These variations in lamination density and depth significantly impact the effectiveness of fracturing treatments in well placement. This study utilized downhole cores from the Shahejie Formation in the Bonan block, and based on the development characteristics of the lamination, a sampling scheme was designed. Small-scale true triaxial hydraulic fracturing experiments were conducted in the laboratory, focusing on the relationship between lamination density and perforation locations. Post-experiment analyses using computed tomography and acoustic emission monitoring examined fracture morphology, width variations, and proppant migration and placement within the fractures. The results indicate that high lamination density influences the propagation path of hydraulic fractures, restricting their vertical penetration through layers. Fracture initiation points closer to the lamination result in lower fluid injection pressure rise rates, thereby reducing the efficiency of the fracturing fluid. Lamination activated at the same depth generally produces narrower fractures than the main hydraulic fractures. Proppants are predominantly distributed within the main hydraulic fractures, with limited vertical migration into the lamination, resulting in the propped volume accounting for less than 10% of the total fracture volume. This study provides new insights and optimization strategies for well placement and perforation positioning in the hydraulic fracturing of organic-rich laminar lithofacies shale reservoirs.

Ventricular and supraventricular ectopic beats burden is correlated with bone mineral density and osteoporotic fracture risk in postmenopausal females

Abstract Introduction Patients (pts) with osteoporosis (OP) have an increased 10-year cardiovascular death risk. Low bone mineral density (BMD) observed in OP may be associated with arrhythmic presentation of cardiovascular diseases (CVD). Few studies assessed the relationship between OP and arrhythmia. Aim Arrhythmias assessment in pts with OP. Methods A total of 103 postmenopausal female pts (mean age 69 +/- 7), consulted by endocrinologist, were divided into 2 groups according to BMD (assessed by dual energy X-ray absorptiometry). BMD measurements, expressed as T-score (T-sc), were taken from the femoral neck (T-sc Neck), entire total hip (T-sc TH) and/or spine (T-sc L2-L4, L1-L4). Arrhythmia was evaluated using 24-hour Holter-ECG monitoring (HM). Major osteoporotic and total hip fracture risks (MOFR and THFR, respectively) were assessed by the FRAX scale. We compared 51 pts with OP (T-sc ≤ -2.5), with 52 matched controls without OP, including 44 pts with osteopenia (T-sc > -2.5). There were no significant differences between the groups regarding the history of stroke, myocardial infarction, coronary artery disease or arterial hypertension. Exclusion criteria included heart failure NYHA >II and/or LVEF <36%, acute coronary syndrome within the last 6 months, severe valvular disease, cardiac implantable electronic device. Results There was a trend towards a greater number of supraventricular and ventricular arrhythmias in the OP group compared to the controls. Arrhythmic burden was significantly correlated with BMD measures: correlations were observed between 24-hour ventricular ectopic beats (VEB) count with T-sc Neck (r=-0.20, p=0.04), with T-sc TH (r=-0.22, p=0.03). The number of supraventricular ectopic beats (SVEB) in HM was also correlated with BMD parameters: T-sc Neck (r=-0.21, p=0.03), T-sc TH (r=-0.23, p=0.02). Multivariate analysis (linear regression model) revealed that age and T-sc TH were independently related with ectopy: age (0.07; CI: 0.01 - 0.13, p=0.03) and T-sc TH (-0.58; CI: -1.07 - -0.08, p=0.02) were predictors for VEB, and SVEB were related to age (0.07; CI: 0.03 - 0.12, p<0.01) and, with borderline significance with T-sc TH (-0.34; CI: -0.699 - 0.012, p=0.058). Ectopic beats count was also positively correlated with osteoporotic fracture risk: VEB with THFR (r=0.206, p=0.04) and SVEB with MOFR (r=0.21, p=0.04). Conclusions The study showed an increased arrhythmia burden as detected in HM in pts with OP. Beside the T-sc TH, age was identified as an independent factor of increased SVEB / VEB. The main significant negative correlations were observed between the number of VEB / SVEB and BMD in femur (T-sc Neck, T-sc TH). Ectopic beats count was also positively correlated with osteoporotic fracture risk: VEB with THFR and SVEB with MOFR.

GeriNOT in the Surgical Inpatient Setting.

The guideline of the Federal Joint Committee (G-BA) on quality assessment measures for the care of patients with hip fracture makes it mandatory for hospitals to use an appropriate geriatric screening instrument in the context of acute inpatient care. After systematic application of GeriNOT and data collection in the admission process with integration into the Hospital Information System (HIS), it is possible to identify potential risks in geriatric patients with other diagnoses as well.With the integration of GeriNOT into the acute inpatient admission process, it was examined whether vulnerable geriatric patients with other diagnoses could benefit from the early initiation of risk identification.The data base for the present study was a retrospective bicentric collection of electronic case records (May 2014 to April 2015, n=3,443). From this primary data set, the subgroup of inpatient acute admissions (n=821) in the orthopaedic/trauma surgery of a study centre was analysed and evaluated with respect to the endpoints "utilisation of needs-based post-inpatient care services" and "new admission to inpatient permanent/short-term care". The predictive power and classification accuracy of GeriNOT of these patients who were 70 years and older to the endpoints were assessed for several groups: total acute admissions, total fractures, hip fracture, and spinal disorders including spinal fractures.A total of 821 patients were admitted as acute inpatients during the study period. The mean age of the patients was 81.4±6.8 years (n=821; 68.1% women, 31.9% men). The following subgroups were formed and analysed: total fractures (n=490), spinal disorders (n=265) including spinal fractures (n=174), and hip fracture (n=108). Both in the overall group (n=821; M=4.279; SD=2.180) and in the subgroups, the mean GeriNOT score was above the threshold ≥4. The highest score was found in the hip fracture group (M=4.852; SD=2.022), and the lowest in the spine fracture group (M=4.177; SD=2.171). At admission, if the terms of variables for requiring treatment were "polypharmacy" and "nursing services already used as needed", there were only slight differences in the diagnostic groups. Admissions from short-term and long-term care occurred in the total group in 16.44% of cases, most frequently with 31.48% in the group of hip fractures, compared to spinal diseases with 6.79%. For this group, GeriNOT detected an elevated risk with respect to the defined endpoints. However, only 4.26% of all patients with identified geriatric risk potential received further geriatric care.The results showed increased geriatric risk in all analysed groups, but most pronouncedly within the group of spinal diseases. The HIS-supported use of GeriNOT offers the possibility of systematic risk identification in acute inpatient admission management. The continuous visualisation of results at HIS workstations throughout the workflow could be used as a starting point for the subsequent application of standardized assessment tools and risk-adjusted treatment pathways. These findings could potentially improve outcomes.

6683 The Interrelationship of Baseline Vitamin K and Vitamin D Status on Incident Fractures: Results from the VITamin D and OmegA-3 TriaL (VITAL)

Abstract Disclosure: S.H. Chou: None. S.L. Booth: None. D. Ratnarajah: None. N. Cook: None. G. Kotler: None. X. Fu: None. J. Buring: None. J.E. Manson: None. M.S. LeBoff: None. Vitamin D and vitamin K have interdependent roles in bone metabolism. We recently reported that, in the VITamin D and OmegA-3 TriaL (VITAL), daily supplemental vitamin D (2000 IU/d) vs. placebo did not reduce fracture risk in 25,871 U.S. men (aged ≥50) and women (aged ≥55).[1] While vitamin D stimulates transcription and translation of osteocalcin (OC) and matrix Gla protein (MGP), vitamin K is needed to carboxylate and activate these proteins. Older adults tend to have low vitamin K intakes, and low vitamin K status may attenuate effects of vitamin D on bone. In this VITAL ancillary study, we tested in a case-cohort sample of 1,162 participants with fractures and an age-sex-matched subcohort size of 2,652, whether baseline low vitamin K status, alone or in combination with lower 25(OH) vitamin D level, predicts incident total, non-vertebral, and hip fractures. The mean (±SD) age of participants was 68.3±7.2 years, 61.5% were female, and 81.7% was Non-Hispanic White. Fractures were reported on annual questionnaires and adjudicated through medical record review. To assess vitamin K function, percent undercarboxylated OC (%ucOC) and dephosphorylated undercarboxylated MGP ([dp]ucMGP) were measured in fasting baseline blood samples, with %ucOC calculated from measures of ucOC and total OC. Higher levels of %ucOC and (dp)ucMGP indicate lower vitamin K status. Serum 25(OH)D was measured by LC-MS/MS and vitamin K biomarkers by sandwich ELISAs (IDS-iSYS Multi-Discipline Automated System). Participants with incident fracture had higher baseline vitamin K status, as assessed by (dp)ucMGP levels, but this was not corroborated by %ucOC. Compared to participants with low baseline vitamin K status and baseline 25(OH) vitamin D levels below the median (30.0 ng/mL), participants with higher baseline vitamin K and D status had a similar incidence of total and non-vertebral fractures. For the 91 hip fracture cases, baseline status of vitamin K and D did not predict hip fracture incidence. In this ancillary study, low vitamin K status by (dp)ucMGP and %ucOC, alone or in combination with baseline 25(OH) vitamin D levels below the median, was not associated with increased fracture incidence. Ongoing analyses are assessing whether phylloquinone levels as another vitamin K biomarker predict incident fracture risk. Furthermore, we have also previously shown that the effects of supplemental vitamin D on total and hip fractures were not modified by baseline vitamin K status in VITAL, the largest randomized controlled trial of supplemental vitamin D vs. placebo on fractures. From our findings in VITAL, higher vitamin K status does not protect against fractures. 1. LeBoff MS, et al. NEJM. 2022. Presentation: 6/1/2024

9275 The Interrelationship of Baseline Vitamin K and Vitamin D Status on Incident Fractures: Results from the VITamin D and OmegA-3 TriaL (VITAL)

Abstract Disclosure: S.H. Chou: None. S.L. Booth: None. D. Ratnarajah: None. N. Cook: None. G. Kotler: None. X. Fu: None. J. Buring: None. J.E. Manson: None. M.S. LeBoff: None. Vitamin D and vitamin K have interdependent roles in bone metabolism. We recently reported that, in the VITamin D and OmegA-3 TriaL (VITAL), daily supplemental vitamin D (2000 IU/d) vs. placebo did not reduce fracture risk in 25,871 U.S. men (aged ≥50) and women (aged ≥55).[1] While vitamin D stimulates transcription and translation of osteocalcin (OC) and matrix Gla protein (MGP), vitamin K is needed to carboxylate and activate these proteins. Older adults tend to have low vitamin K intakes, and low vitamin K status may attenuate effects of vitamin D on bone. In this VITAL ancillary study, we tested in a case-cohort sample of 1,162 participants with fractures and an age-sex-matched subcohort size of 2,652, whether baseline low vitamin K status, alone or in combination with lower 25(OH) vitamin D level, predicts incident total, non-vertebral, and hip fractures. The mean (±SD) age of participants was 68.3±7.2 years, 61.5% were female, and 81.7% was Non-Hispanic White. Fractures were reported on annual questionnaires and adjudicated through medical record review. To assess vitamin K function, percent undercarboxylated OC (%ucOC) and dephosphorylated undercarboxylated MGP ([dp]ucMGP) were measured in fasting baseline blood samples, with %ucOC calculated from measures of ucOC and total OC. Higher levels of %ucOC and (dp)ucMGP indicate lower vitamin K status. Serum 25(OH)D was measured by LC-MS/MS and vitamin K biomarkers by sandwich ELISAs (IDS-iSYS Multi-Discipline Automated System). Participants with incident fracture had higher baseline vitamin K status, as assessed by (dp)ucMGP levels, but this was not corroborated by %ucOC. Compared to participants with low baseline vitamin K status and baseline 25(OH) vitamin D levels below the median (30.0 ng/mL), participants with higher baseline vitamin K and D status had a similar incidence of total and non-vertebral fractures. For the 91 hip fracture cases, baseline status of vitamin K and D did not predict hip fracture incidence. In this ancillary study, low vitamin K status by (dp)ucMGP and %ucOC, alone or in combination with baseline 25(OH) vitamin D levels below the median, was not associated with increased fracture incidence. Ongoing analyses are assessing whether phylloquinone levels as another vitamin K biomarker predict incident fracture risk. Furthermore, we have also previously shown that the effects of supplemental vitamin D on total and hip fractures were not modified by baseline vitamin K status in VITAL, the largest randomized controlled trial of supplemental vitamin D vs. placebo on fractures. From our findings in VITAL, higher vitamin K status does not protect against fractures. 1. LeBoff MS, et al. NEJM. 2022. Presentation: 6/1/2024

7867 Treatment-Related Changes in Total Hip Bone Mineral Density and Fracture Risk Reduction for Drugs With Different Mechanisms of Action: The FNIH-ASBMR-SABRE Project

Abstract Disclosure: T. Vilaca: None. M.T. Schini: None. A.R. Thompson: None. E. Vittinghoff: None. L. Lui: None. S.K. Ewing: None. D.C. Bauer: None. D.M. Black: None. M. Bouxsein: None. R. Eastell: Consulting Fee; Self; Immunodiagnostic Systems, CL Bio, CureTeQ, Biocon, Takeda, UCB. Grant Recipient; Self; Alexion Pharmaceuticals, Inc., Osteolabs. Speaker; Self; Pharmacosmos, Alexion Pharmaceuticals, Inc., Amgen Inc, UCB. Introduction: To date, trials of new anti-osteoporosis therapies have used fractures as primary endpoints. In the FNIH-ASBMR-SABRE project, we posited that the treatment-related change in total hip BMD (THBMD) could be used as a surrogate endpoint for fractures in future clinical trials of new osteoporosis therapies. To demonstrate this, we compiled a large dataset of individual patient data (IPD) from randomized trials and showed a strong association between the change in THBMD at 24 months and reduction in fracture risk. To further explore the use of THBMD as a surrogate endpoint, here we examine whether the association is robust across drugs with different mechanisms of action. Methods: We used IDP (n>120,000 participants) from 22 randomized, placebo-controlled, double-blind trials of osteoporosis medications (17 anti-resorptive, 3 PTH analogs, 1 odanacatib, and 1 romosozumab). We calculated the treatment-related difference (active-placebo) in mean % change in THBMD at 12, 18, and 24 months for each trial. We determined the treatment-related fracture risk reductions for the entire follow-up period, using logistic regression for radiologic vertebral fractures and Cox regression for all clinical fractures (a combination of non-vertebral and clinical vertebral fractures). We used meta-regression to estimate the study-level association (r2) between treatment-related differences in THBMD changes and fracture risk reduction, including only the 17 trials of anti-resorptive drugs and then using the entire set of 22 trials. Since there were only 3 trials of anabolic drugs, we did not perform separate analyses for the anabolic trials. Results: The r2 values were similar between all trials and antiresorptive trials only for both fracture outcomes at all time points. Specifically, for vertebral fractures, the r2 was 0.59 vs 0.70 at 12 mo, 0.69 vs 0.74 at 18 mo, and 0.73 vs 0.78 at 24 mo for all trials vs anti-resorptive trials only. For all clinical fractures, the r2 was 0.46 vs 0.51 at 12 mo, 0.64 vs 0.60 at 18 mo, and 0.71 vs 0.65 at 24 mo for all trials vs anti-resorptive trials only. Conclusion: These results demonstrate that the associations between treatment-related changes in THBMD and fracture risk reductions are robust across anti-osteoporosis therapies with varying mechanisms of action. We conclude that the treatment-related difference in THBMD change would predict fracture reduction equally well for drugs with different mechanisms of action. Presentation: 6/2/2024

Synchronous vertical fracture propagation of multi-layer radial wells for enhancing stimulated height in shale oil reservoir

The diversity of interlayers in shale oil reservoir leads to a low degree of vertical reconstruction. This paper aims to propose a method to guide the synchronous initiation of hydraulic fractures in different layers by drilling multi-layer radial wells in spatial positions, and to form a fracture network that satisfies the vertical propagation range and complexity. In this paper, a 3D (three-dimensional) multi-layer radial well fracturing model considering fluid-mechanics coupling is established and the properties of shale oil reservoir are characterized according to the field geological profile. The influences of radial well spacing, fracturing fluid injection rate, and fracturing fluid viscosity on vertical fracture communication in multi-layer radial wells are investigated. The results show that the radial well has the characteristics of guiding fracture penetrating interlayers. Reducing radial well spacing and appropriately increasing injection rate and viscosity are beneficial to improving vertical fracture propagation ability. However, high fracture fluid viscosity under the same displacement will lead to a significant increase in fracture aperture and weaken the total fracture area. In addition, if the stress interference around the radial wells is low, the radial well can be located in the middle of each layer to minimize the fracture height limitation. This study can provide a solution idea for vertical propagation limitation of hydraulic fractures in shale oil reservoir.

Integrated study of hydraulic/CO2 fracturing and production coupled with a THM-D process in ultra-shallow shale reservoirs

To explore fracturing technology for vertical wells in ultra-shallow shale gas reservoirs, a coupled thermo-hydro-mechanical-damage (THM-D) fracturing and production integration model is established in this study. In addition, a new coupled hydro-mechanical damage model is established to calculate fracture evolution. These two models are validated through theoretical models and field data, respectively. Based on these models, the quality of fracturing under different geological parameters, fracturing parameters, and fracturing technology is compared and analyzed. The results show that the distribution of natural fractures significantly influences fracturing and production. In addition, due to the high leak-off in the ultra-shallow shale reservoir, the total fracture length and cumulative production after 720 days of carbon dioxide fracturing are only 70.35% and 77.26% of the values achieved by hydraulic fracturing, respectively. Therefore, it is necessary to consider reducing carbon dioxide leak-off in the design of carbon dioxide fracturing in ultra-shallow shale reservoirs. Fracturing efficiency also should be considered when designing fracturing time. When the injection rate is 5 m3/min, the efficiency drops sharply if the fracturing time exceeds 67.45 min. The production of hydraulic fracturing and carbon dioxide fractured wells has also been studied when fracturing methods without proppant are used. This study found that a satisfactory production rate can also be achieved in ultra-shallow shale gas reservoirs when fracturing without proppant.

Fragility Fracture of Proximal Tibia in A Wheelchair-Bound 54-Year-Old Female Patient

Sedentary behavior is one of the risk factors of fracture, in which mild activity was found to be inversely associated with hip, vertebral, and total fracture. Other study also found non-linear association of fracture risk with lower and higher physical activity was associated with higher risk of any fracture compared to a mean physical activity. In this study, we reported a 54-year-old wheelchair bound female with fracture on the proximal tibia cause by low-energy trauma. This research underscores the importance of early identification of fracture risk factors, especially in vulnerable populations such as older adults who are wheelchair-bound. Early interventions that include lifestyle changes, increased physical activity, and nutritional management are essential to prevent further fractures and improve bone health. Identifying the risk of fractures on elderly patient may be beneficial for prevention of fractures especially in wheelchair-bound elderly individual.

Assessment of concrete-to-concrete shear bond behavior using 3-D direct shear testing

The interfaces that develop when fresh concrete is poured onto existing substrates are noted for their vulnerability and influence on the durability and integrity of the composite structure. Studies on the shear bond properties and failure mechanisms of such composite concrete-to-concrete joints under normal stress are essential for developing predictive and numerical models that accommodate various levels of joint substrate roughness. This study aims to use an innovative 3D shearing box, BCR3D, to analyze the shear behavior of concrete-to-concrete joints under direct shear tests at a constant normal stress. The influence of the degree of surface roughness on the pure shear behavior of these joints was assessed at a normal stress level of 1 MPa. The substrate post-hardening surface morphology was evaluated using a high-resolution laser profilometer. Statistical surface roughness parameters were computed using MATLAB. A parametric study was carried out involving bond strength, residual shear stress, contractive-dilative behaviors, and total fracture energy. Results showed that bond strength, dilative normal displacement, and total fracture energy were proportional to the substrate surface roughness. Residual shear stress was not affected by the initial surface roughness. Dilative normal displacements were more significant for specimens with higher surface substrate roughness due to interlocking, with values reaching up to 1.77 mm. Joints with high substrate surface roughness exhibited similar bond strength and fracture energy to those obtained from the monolithic specimens, underscoring the significance of substrate preparation before casting new concrete layers.

Efficacy and safety of aspirin in venous thromboembolism prevention after total hip arthroplasty, total knee arthroplasty or fracture.

Background: This study aims to analyse the efficacy and safety of aspirin in the prevention of venous thromboembolism (VTE) for patients undergoing total hip arthroplasty (THA), total knee arthroplasty (TKA) or fracture. Patients and methods: Two independent investigators searched PubMed, Embase, Cochrane and ClinicalTrials.gov from January 2000 to June 2023 to retrieve randomized control trials (RCTs) about aspirin in VTE prevention after arthroplasty or fracture. Then, the relative risk (RR) was utilized to evaluate its efficiency and safety. Results: A total of 16 RCTs with 27,864 patients were included. There was no statistical difference in the incidence of deep-vein thrombosis (RR: 1.31, p = 0.100), pulmonary embolism (RR:1.05, p = 0.850), VTE (RR:1.28, p = 0.290), major bleeding (RR:0.96, p = 0.900), and death (RR:1.01, p = 0.960) between the aspirin group and the anticoagulants group. Subgroup analysis showed that a relatively higher incidence of deep-vein thrombosis in patients undergoing TKA (RR:1.49, p = 0.030), fracture (RR:1.48, p = 0.001), patients receiving 81 mg aspirin twice daily (RR:1.48, p = 0.001) and patients from North America (RR:1.57, p<0.001) when comparing aspirin with anticoagulants. Meanwhile, the incidence of VTE was higher in patients receiving 100 mg aspirin once daily (RR:1.82, p<0.001) compared with anticoagulants. Additionally, the incidence of all bleeding (RR:2.00, p = 0.030) was higher in patients receiving aspirin in Asia compared with anticoagulants. Conclusions: In terms of clinical effectiveness and safety, aspirin (antiplatelet agent) was generally not inferior to anticoagulants in the prevention of VTE after THA, TKA, or fracture. Notably, the clinical effectiveness of aspirin was affected by different surgical types, the doses of aspirin and races.

Martian Impact Fracturing Pervasively Influences Habitability

AbstractOn Mars, the lack of either plate tectonics or a prominent erosional hydrological cycle since the Noachian means geological changes caused by asteroid and comet impact events have been preserved. On Earth, surviving impact‐induced fractures are localized to the relatively few preserved craters on the planet. We estimate that the shell of impact‐fractured rock on Mars (the “impact‐sphere”) could provide between 9,200 times the surface area of a Mars radius sphere and up to 100 times this value, depending on the assumptions made, as potential microbially accessible space. Although &gt;93% of craters we consider are smaller than 10 km in diameter, they contribute only about 5% of the total fracture surface area generated by all craters, making complex craters the dominant process for potential habitat formation. Microbiological data from terrestrial impact craters suggest that these fractures could have significantly enhanced local habitability by providing pathways for fluid flow, and thus nutrients and energy. However, unlike on Earth, the geological history of Mars means that pervasive impact fractures may also have provided pathways for Hesperian and Amazonian brines to infiltrate the subsurface and locally reduce habitability. Combining the fracture data with previous microbiological observations provides testable hypotheses for Martian drilling missions.

Effect of Al–Zr and Si–Zr atomic pairs on phases, microstructure and mechanical properties of Si-alloyed (Ti28Zr40Al20Nb12)100-xSix(x=1, 3, 5, 10) high entropy alloys

The phases, microstructure, and mechanical properties of Si-alloyed (Ti28Zr40Al20Nb12)100-xSix(x = 1, 3, 5, 10) high entropy alloys are studied. Although silicides were not detected in the as-cast 1 at. % Si-alloyed sample, after annealing all the four alloys have the same phase composition: the Zr5Al3-type phase, Zr5Si3-type silicides, and the BCC/B2 dual-phase matrix, indicating that 1 at. % Si addition is adequate for the formation of silicides in equilibrium. The phase morphologies show a dependence on the Si content and the cooling rate, which changed from the occurrence of columnar grain zones together with coarse dendrites of the as-cast 1 at. % Si-alloyed alloy to four different cooling-rate-related morphologies in the other three as-cast alloys. After heat treatment, differently shaped precipitates tend to aggregate and spherize, and a three-step-shaped phase morphology is observed when the Si content is above 5 at. %. All precipitates are rich in Zr due to either the strong Si–Zr pair or Al–Zr pair, but heterogeneous distributions of Si and Al exist. An increase of the Si content led to a gradual decrease of the compressive strength in both as-cast and annealed samples, yet the total fracture strain does not show monotonously decrease trend. 5 at. % Si-alloyed samples possessed a higher total fracture strain than the 3 at. % Si-alloyed samples.

Frailty Status, Sedentary Behaviors, and Risk of Incident Bone Fractures.

The associations of physical pre-frailty and frailty with bone fractures and the modified effect of sedentary lifestyle remain uncertain. This study was performed to explore the association of physical pre-frailty and frailty with risk of incident bone fractures, and test the modification effects of sedentary lifestyle and other risk factors. This cohort study included 413 630 participants without bone fractures at baseline in the UK Biobank study between 2006 and 2010 and followed up to 2021. The mean age of the participants was 56.5 years. A total of 224 351 (54.2%) enrolled participants were female and 376 053 (90.9%) included participants were White. Three Cox regression models were constructed to analyze the association of pre-frailty and frailty with total fractures, hip fractures, vertebrae fractures, and other fractures. As compared with the physical nonfrailty group, the multivariate-adjusted hazard ratios were 1.17 (95% confidence interval [CI]: 1.14-1.21) and 1.63 (95% CI: 1.53-1.74) for the physical pre-frailty group and frailty group, respectively (p-trend < .001). In addition, we found that sedentary behavior time significantly accentuated the associations of physical pre-frailty and frailty with total fractures (p-interaction <.001), hip fractures (p-interaction = .013), and other fractures (p-interaction <.001). Our results indicate that physical pre-frailty and frailty are related to higher risks of bone fractures; such association was more pronounced among those with longer sedentary behavior time.

Illicit cocaine and opioid drug-related maxillofacial trauma: a 10-year review of a state-wide database of all hospitals admissions

The aim of this study was to investigate the characteristics of illicit cocaine and opioid drug-related facial trauma and determine whether the presence of cocaine or opioid drug use in facial trauma patients influenced the cause of injury, morbidity, or management. A retrospective observational cohort study was performed using records from a state-wide database of all patients who presented to a Victorian hospital with a facial fracture between 2004 and 2014. Data collected included demographics, concomitant opioid and cocaine use, mechanism of injury, facial injuries, and management. Statistical analysis was done using chi-square test, Student's t tests, binary logistic regression analysis, and multivariable linear regression analysis. Results were considered statistically significant if P < .05. A total of 54,613 patient presentations for facial trauma were analyzed with 363 patients in the cocaine and opioid-related group, and 54,250 patients in the nondrug-related group. Patients with illicit drug use were more likely to have facial fractures caused by interpersonal violence when compared with nondrug users (47.9% vs 23.5%, OR = 2.23, P < .001). Opioid and cocaine users had 0.3 more total fractures per presentation, which included more midface and skull fractures, and more facial lacerations (P < .001). There was no statistically significant difference in the need for surgical management between the two groups. Opioid and cocaine affected patients also on average had a longer hospital stay of 3.4 days and required 0.9 more allied health inputs during their admission when compared with nondrug users (P < .05). This effect was similarly reflected when controlling for confounding variables (P < .001). Concomitant cocaine or opioid use in facial trauma patients leads to more violence-related injuries with higher morbidity and healthcare costs.

Phase-field modelings of fracture investigate the influence of interfacial effects on damage and optimal material distribution in brittle inclusion-matrix structures

This present work uses the phase-field modelings to investigate the influence of interfacial effects on damage and mechanical behavior, as well as the optimal distribution of the inclusion shape within brittle inclusion-matrix structures in various typical cases. These two constituent phases in the structures are assumed to be either isotropic or anisotropic. To achieve these goals, this work will: (i) use the phase-field modelings either considering or neglecting interfacial debonding, and the anisotropic phase-field modeling; (ii) determine and incorporate the strain tensor orthogonal decompositions into each specific phase-field modeling to enhance the accuracy and effectiveness of the simulation methods; (iii) combine the phase-field modelings with the BESO topology optimization algorithm to analyze the influence of interfacial effects on relationship curves and the optimal distribution of the inclusion shape. Through proposed numerical examples, it is demonstrated that the interfacial effects strongly influence crack paths, behavior curves, and optimal material distribution in structures. When considering interfacial effects, cracks are almost unable to penetrate into the inclusion phase. However, when neglecting interfacial effects, cracks propagate into the inclusion phase. This reason makes the structure more difficult to damage than when considering the interfacial effects, as evidenced by greater peak load values in behavior curves and greater total fracture resistance of the material. Especially in the example of inclusion phase optimization, the total fracture resistance value of the case neglecting interfacial effects is more than 107.9% greater than that considering interfacial effects.

Radiological characteristics and injury mechanism of Logsplitter injury: a descriptive and retrospective study

BackgroundLogsplitter Injury is a type of high-energy ankle fracture dislocation. The mechanism of injury has not been described in detail. A detailed understanding of the radiological features and pathological changes can further guide treatment.MethodsBetween April 2009 and December 2018, a retrospective analysis was conducted on 62 patients with Logsplitter injury. The study analysed the characteristics of fibular injury, tibial injury, syndesmosis injury, medial injury and lateral ligament injury on preoperative X-ray and CT scans. The incidence of the different injury types was summarised. The correlation between Logsplitter injuries and the mechanisms causing them were analysed using the Lauge-Hansen classification of ankle fractures.ResultsThe study provides data on the types of fractures observed. Of the total fractures, 98.4% were open fractures. The fibula injuries were classified as no fracture (1.6%), transverse or short oblique fractures (61.3%), butterfly fragments (25.8%), and comminuted fractures (11.3%). The tibial injuries included compression of lateral articular surfaces (38.7%) and posterior compressions (6.5%). Medial injuries, including medial malleolar fractures, accounted for 87.1%, and deltoid ligament rupture accounted for 12.9%. The study found that injuries to the syndesmosis consisted of simple ligament ruptures (11.3%), Tillaux fractures (8.1%), Volkmann fractures (43.5%), and Tillaux and Volkmann fractures (37.1%). In 12.9% of cases, there was a complete rupture of the lateral collateral ligament. Based on the Lauge-Hansen classification, 87.1% of injuries were pronation-abduction injuries, while 8.1% were pronation and external rotation injuries, and 1.6% were supination external rotation injuries. Furthermore, 3.2% of cases could not be classified.ConclusionThe pathoanatomic characteristics of Logsplitter injury are diverse, with some cases accompanied by collateral ligament injury. It is important to note that these evaluations are objective and based on current results. The most common injury mechanism is vertical violence combined with abduction, although in some cases, it may be a vertical combined external-rotation injury.Level of evidence(4) case series.Trial registrationThis study has been approved by the ethical research committee of the Honghui Hospital of Xi’an Jiaotong University, under the code: 202,003,002.

Vitamin D Supplementation and the Incidence of Fractures in the Elderly Healthy Population: A Meta-analysis of Randomized Controlled Trials.

Although a well-established component of bone metabolism, the efficacy and safety of vitamin D supplementation for the prevention of fractures in elderly healthy individuals is still unclear. To perform a meta-analysis comparing vitamin D supplementation with placebo and its contributions on fracture incidence. This meta-analysis was registered in the International Prospective Register of Systematic Reviews (PROSPERO), under protocol CRD42023484979. We systematically searched PubMed, Embase, and Cochrane Central databases from inception to November 2023 for randomized controlled trials (RCTs) comparing vitamin D supplementation versus placebo in individuals with 60years of age or more and without bone related medical conditions such as cancer and osteoporosis. Seven RCTs with 71,899 patients were included, of whom 36,822 (51.2%) were women. There was no significant difference in total fracture incidence (RR 1.03; 95% CI 0.93-1.14; p = 0.56; I2 = 58%) between groups or subgroups. However, women had an increased risk for hip fractures (164 vs. 121 events; RR 1.34; 95% CI 1.06-1.70; p = 0.01; I2 = 0%). There was no significant difference in non-vertebral fractures, osteoporotic fractures development, or falls (RR 1.02; 95% CI 0.94-1.12; p = 0.6; I2 = 47%; RR 0.97; 95% CI 0.87-1.08; p = 0.63; I2 = 0%; RR 1.01; 95% CI 0.97-1.04; p = 0.66; I2 = 55%, respectively). Vitamin D supplementation does not reduce the total fracture development rate in the elderly healthy population, and it may increase the incidence of hip fractures among elderly healthy women. This finding suggests refraining from prescribing high intermittent doses of vitamin D, without calcium, to individuals aged 60 or older with unknown vitamin D serum concentration or osteoporosis status and inadequate calcium intake.

Influence of tectonic stress field on oil and gas migration in the Tahe Oilfield carbonate reservoir: Identification of areas favorable for reservoir formation

An understanding of the tectonic stress field distribution in the carbonate reservoirs of the Tahe Oilfield is essential for oil and gas migration and reservoir reconstruction. This study adopts a geological genesis perspective and integrates the unique attributes of the carbonate reservoirs in the Tahe Oilfield to simulate three-dimensional stress fields using the finite element method and Petrel software. The simulation, which takes pore pressure and boundary constraints into consideration, aligns with the findings of acoustic emission tests conducted by previous researchers and validates the model by corroborating the maximum horizontal principal stress direction with imaging logging interpretations. With subsequent utilization of the generalized Coulomb-Mohr shear failure criterion and the Griffith generalized maximum tensile stress criterion, the simulated stress enables the prediction of the total fracture intensity. To complement this analysis, we integrate seismic data and fault formation mechanisms to characterize variations in fracture intensity within distinct regions of the study area. Three key findings emerge from this investigation. First, due to the Hercynian thermal event, X-shaped conjugate faults display a disproportionately high degree of development compared to other primary fractures. Analyzing the mechanisms of formation and development of these X-shaped strike-slip faults reveals discernible differences in deformation characteristics between NW-trending and NE-trending faults, with the former exhibiting a greater propensity for fracture rupture and efficient oil-gas migration. Second, fault intersections are critical and efficient conduits for fluid accumulation and thereby contribute to reservoir formation. Lastly, exclusive of X-shaped conjugate faults, NE-trending faults exhibit the greatest propensity for oil and gas accumulation and migration. Collectively, these findings facilitate the identification of areas favorable for oil and gas migration and provide a crucial mechanical analysis that can inform the exploration and development of the Tahe Oilfield.