Fracture Characteristics Research Articles

Femoral neck system (FNS) versus 4 cannulated compression screws (CCSs) in the treatment of young patients with Pauwels type III femoral neck fracture: a retrospective comparative study

ObjectiveThis study aimed to evaluate the clinical effectiveness of the femoral neck system (FNS) compared to four cannulated compression screws (CCSs) for managing Pauwels type III femoral neck fractures in young patients.MethodsA retrospective analysis was conducted on young patients with Pauwels type III femoral neck fractures treated at our hospital from January 2021 to December 2022. Patients were categorized into two groups based on their respective internal fixation methods: the FNS group (32 cases) and the CCSs group (41 cases). Various demographic and clinical variables, including age, gender, fracture side, mechanism of injury, Garden classification, and time interval between injury and surgery, were collected. Comparisons were made between the two groups regarding operative duration, intraoperative blood loss, length of hospital stay, hospitalization expenses, time to fracture healing, and Harris hip score at one year post-surgery. Additionally, postoperative complications such as wound infections, nonunion, femoral neck shortening, avascular necrosis of the femoral head, and hardware failure were analyzed. Follow-up duration ranged from 12 to 24 months for all patients.ResultsThere were no significant differences between the FNS and CCSs groups in terms of demographic characteristics, fracture characteristics, time to fracture healing, duration of hospital stay, and Harris hip score at one year post-surgery (p > 0.05). However, the CCSs group exhibited significantly shorter operative time, reduced intraoperative blood loss, and lower hospitalization costs compared to the FNS group (p < 0.05). Patients treated with FNS had longer operative durations (82.33 ± 28.85 min vs. 66.58 ± 14.38 min, p = 0.006), higher blood loss (106.67 ± 65.83 mLvs.70.00 ± 27.39 mL, p < 0.001), and increased hospitalization expenses (58,345.98 ± 3706.57 RMB vs. 35,427.63 ± 3019.30 RMB, p < 0.0001). The incidence of postoperative complications was 21.8% in the FNS group and 26.8% in the CCSs group (p > 0.05), with no significant differences observed in the rates of wound infections, femoral neck shortening, femoral head necrosis, nonunion, and hardware failure between the two groups (p > 0.05).ConclusionIn the management of Pauwels type III femoral neck fractures in young patients, FNS demonstrates clinical efficacy comparable to CCSs. However, considering factors such as operative time, intraoperative blood loss, and hospitalization costs, CCSs may be preferred.

Multicentric Epidemiological Analysis on Medial Wall Fractures of the Orbit: 10‐Year Retrospective Study Between the Centres of Perugia and Ancona

ABSTRACTStudy Design and ObjectivesThe incidence of isolated fractures of the orbital medial wall is moderate because of the low bone thickness. Our study aimed to investigate demographic variables, fracture features and statistical correlations associated with these fractures retrospectively.Materials and MethodsA total of 57 patients with isolated orbital medial wall fracture, admitted at the Maxillofacial Surgery Unit of Perugia University Hospital and Maxillofacial Surgery Unit of Ospedali Riuniti di Ancona, from 2014 to 2023 were enrolled in the study.Age, sex, comorbidities, post‐traumatic clinical manifestations and defect size and side were all evaluated in patients. Pearson's regression coefficient (r) was used for statistical analysis.ResultsThe fractures were more frequent in men (male to female ratio 2.16:1) primarily as a result of motor vehicle accidents (30% of cases); the average age was 48 years; enophthalmos, diplopia and ocular motility abnormalities were observed in 31%, 23% and 21%, respectively.According to statistical analysis, fracture area was significantly correlated with age, with older patients having larger fractures (p &lt; 0.001); interpersonal violence and traffic accidents were related to younger age (p &lt; 0.001). In a recent analysis of the data, it was found that isolated orbital medial wall fractures occur more frequently in young men (&lt; 40 years) due to road accidents or interpersonal violence. Patients' age is statistically correlated with fracture area, with older patients having larger defects.ConclusionsThis research assesses both the demographic and fracture characteristics of pure medial orbital wall fractures, aiming to enhance the understanding of this clinical scenario and to evaluate optimal treatment strategies.

In Situ EBSD Observation and Numerical Simulation of Microstructure Evolution and Strain Localization of DP780 Dual-Phase Steel

To reveal the microstructural evolution and stress–strain distribution of 780 MPa-grade ferrite/martensite dual-phase steel during a uniaxial tensile deformation process, the plastic deformation behavior under uniaxial tension was studied using in situ EBSD and crystal plastic finite element method (CPFEM). The results showed that the geometrically necessary dislocations (GND) in ferrite accumulated continuously, which is conducive to the formation of grain boundaries, but the texture distribution did not change significantly. The average misorientation angle decreased and the proportion of low-angle grain boundaries increased with the increase of strain. At high strain, the plastic deformation mainly occurred in the soft ferrite region within a 45° distribution from the loading direction. In the undeformed state, the texture of the dual-phase steel was characterized by α-fibers and γ-fibers. Interfacial debonding was caused by the accumulation of geometrically necessary dislocations. The fracture morphologies showed that the specimens had typical ductile fracture characteristics.

Research on the analysis of morphological characteristics in pediatric femoral neck fractures utilizing 3D CT mapping.

Proximal femoral fractures in children are challenging in clinical treatment due to their unique anatomical and biomechanical characteristics. The distribution and characteristics of fracture lines directly affect the selection of treatment options and prognosis. Pediatric proximal femur fractures exhibit distinctive features, with the distribution and characteristics of the fracture line playing a crucial role in deciding optimal treatment. The study aims to investigate the morphological characteristics of pediatric femoral neck fracture (FNF) from clinical cases by fracture mapping technology and to analyze the relationship between fracture classifications and age. The CT data were collected from 46 consecutive pediatric inpatients' diagnoses of FNF from March 2009 to December 2022. The fracture imaging was reconstructed in three dimensions and performed the simulated anatomical reduction by Mimics and 3-matic. Both Delbet classification and Pauwels angle classification were documented according to the fracture line in each patient. Furthermore, all of the fracture lines in these patients were superimposed to form a fracture map and a heat map. This study included 24 boys and 22 girls (average age, 9.61 ± 3.17years (4 to 16years)). The fracture lines of the anterior and superior femoral neck were found to be mainly located in the middle and lower regions of the femoral neck, while fracture lines of the posterior and inferior neck were mainly concentrated in the middle region. Most children younger than 10years had Delbet type III of fracture (69%), whereas those older than 10years had Delbet type II of fracture (73%). Furthermore, most children had Pauwels angle type III of fracture (63%), especially in those over 10years old (80%) (p = 0.0001). FNF in children is predominantly located in the middle and lower regions of the neck. Older children may be prone to be affected with higher fracture location of FNF or unstable type of fracture.

The focal mechanism and field investigations of mining-induced earthquake by super-thick and weak cementation overburden strata fracturing

Mining-induced earthquake (MIE) is a non-natural earthquake induced by mining activities. In Ordos mining area, super-thick and weak cementation overburden strata (STWCS) are common occurrence in Jurassic coal seam overlying strata. To explain and quantify the focal mechanism and roof fracture characteristics of MIE under the STWCS, the surface subsidence, ground borehole televiewer imaging and microseismic monitoring technologies were used to observe the fracturing of STWCS. The relative moment tensor method was also used to explore quantify focal mechanism of MIE. The results show that the development height of rock fractures increases, and the STWCS start to break when the panel below retreats along goafs. During this period, the surface stepped subsidence increases rapidly, and MIEs with magnitude above 2.0 begin to appear. The inversion matrix is constructed with the relative moment tensor method to solve the source mechanism of coal mining microearthquakes. The matrix improves the inversion efficiency and accuracy, thus being suitable for solving the focal mechanism of MIE by roof breaking. When coal seam is mined under the STWCS, the dip angle of focal rupture surface is mainly between 0° and 30°, accounting for about 50% of the total. The seismic source is mainly featured with roof horizontal separation tension and roof rotation compression instability. During mining along goafs, the seismic sources displayed a tendency of upward expansion and the shear slip ruptures were more than that in the solid coal mining stage. The focal mechanism of the MIEs in Shilawusu Coal mine was caused by the primary and periodic tension rupture of the STWCS and shear slip rupture. With the continuous mining of the panel, there is still the possibility of another round of MIEs. The research results provide a reference for the prediction, risk assessment and disaster control of MIEs under extremely thick overburden strata.

Numerical simulation of fracture evolution behaviors in deep roadway surrounding rock containing discontinuous joints

To explore the internal bearing characteristics and fracture evolution laws of discontinuous jointed rock mass in deep roadways, the −600 m main roadway in Xin ’an Coal Mine was used as the research background. The fracture fractal dimension D was employed to characterize the joint density, and an intermittent jointed roadway model, both without support and with anchor cable support, was modeled using the particle flow software PFC2D. The internal stress, deformation, and fracture characteristics of intermittent jointed surrounding rock in tunnels with different support methods and joint densities were studied from a microscopic perspective. The results indicate that during the bearing process of the bolt anchor support and unsupported roadway discontinuous jointed rock mass model, the main bearing area of both models transferred from the surface rock mass to the deep rock mass. The tensile cracks of the anchor cable support model were reduced by 57.7% compared with the unsupported model, effectively suppressed the tensile failure of the surrounding rock, and the convergence of the surrounding rock was substantially reduced. The density of intermittent joints was negatively correlated with the bearing capacity of the surrounding rock mass of roadways, and the increase of joint density the overall failure of the surrounding rock, and the possibility of roadway destabilization was increased. Importantly, the number and distribution of intermittent joints in the surface surrounding rock were closely related to the rupture characteristics of the roadways. When the load exceeded the ultimate load of the deep surrounding rock, stress fluctuation occurred due to the stress drop caused by its destruction. This fluctuation promoted the development of intermittent joints in the surface surrounding rock, increasing the risk of roadway destabilization.

Investigation of fracture properties and microbially induced calcite precipitation (MICP) restoration in coal mining areas within the diverse Terrain of Northern Shaanxi, China

The complex and diverse nature of coal mining sites, including different landforms and working conditions, presents challenges for rehabilitation efforts. To address this, we conducted a comprehensive experimental study focusing on microbially induced calcium carbonate precipitation (MICP) remediation, considering the fracture characteristics of coal mining sites. The MICP-restored samples were subjected to confined/unconfined compressive strength, uniaxial/triaxial permeability, and souring tests to assess their restoration efficacy. The results showed that under similar mining conditions, the average depth of parallel fractures was 0.185 m for loess ridges, 0.16 m for the valley, and 0.146 m for the blown-sand region, while the average depth for boundary fractures was 0.411 m for loess ridges, 0.178 m for the valley, and 0.268 m for the blown-sand region. Notably, parallel fractures showed negligible filling in all landforms, whereas boundary fractures in the blown-sand region were completely filled with wind-deposited sand. The valley landform was filled with alluvium and wind-deposited sand, whereas the loess landform was filled with wind-deposited sand and loess. MICP-restored soil samples in all landforms achieved a strength comparable to remolded fracture-free soil samples. Across all landforms, the maximum permeability coefficient of MICP-restored soil samples closely matched that of remolded fracture-free soil samples. Under similar topographic and rainfall conditions MICP restorations scoured 31.3 g on blown-sand region, 19.3 g on loess ridges, and 17.6 g on valleys. These research findings provide an experimental foundation for MICP repair of coal mining ground fractures.

Hip Region Stress Fracture in South Korean Military Recruits: Private's Fracture.

This study aims to analyze the characteristics of hip region stress fractures (HSFs) within a South Korean military cohort and identify the associated risk factors to provide insights for treatment and prevention strategies. Additionally, we will report the epidemiologic data and clinical outcomes of treating HSF within the second largest military hospital. Between January 2022 and December 2023, this retrospective case series revised all HSF patients' medical records to analyze demographic and epidemiologic data and clinical progress. The incidence rate was calculated using the number of conscripted soldiers based on publicly open available statistics from government institution. A total of 95 hips from 60 patients were included in this study, and 35 patients (58.3%) exhibited bilaterality. The seasonal variation of HSF patients showed a bimodal distribution, with peaks from April to June and October to December. The incidence rate per 100,000 person-years is estimated to be between 55.3 in 2022 and 67.9 in 2023. Hip region stress fractures can also be termed as "private's fractures," which accurately describe their nature. It is crucial to identify cases that necessitate early diagnosis and surgical intervention. Epidemiologically, HSF demonstrates high bilaterality and a bimodal distribution throughout the year. During this period, unit commanders and military doctors should be cautious of HSF among soldiers and conduct appropriate screenings.

Risk factors for one-year mortality in 440 femoral peri-implant fractures: insights from the PIPPAS prospective, multicentre, observational study.

The Peri-Implant and PeriProsthetic Survival AnalysiS (PIPPAS) study aimed to investigate the risk factors for one-year mortality of femoral peri-implant fractures (FPIFs). This prospective, multicentre, observational study involved 440 FPIF patients with a minimum one-year follow-up. Data on demographics, clinical features, fracture characteristics, management, and mortality rates were collected and analyzed using both univariate and multivariate analyses. FPIF patients were elderly (median age 87 years (IQR 81 to 92)), mostly female (82.5%, n = 363), and frail: median clinical frailty scale 6 (IQR 4 to 7), median Pfeiffer 4 (1 to 7), median age-adjusted Charlson Comorbidity Index (CCI) 6 (IQR 5 to 7), and 58.9% (n = 250) were American Society of Anesthesiologists grade III. Overall, 90.5% (n = 398) of the patients were treated surgically, 57.0% (n = 227) retained the implant, and 88.7% (n = 353) managed with fixation. Mortality rates were 8.2% (n = 3.6) in-hospital, 11.4% (n = 50) at 30 days, 21.1% (n = 93) at six months, and 21.6% (n = 95) at 12 months. Medical complications, mainly delirium, were common in the acute setting (52.7%, n = 215). The nonunion rate was 4.1% (n = 18). Mortality risk factors in the univariate analysis were age, living at a nursing home, no walking outdoors, frailty variables, fractures in the distal epiphysis, fractures around a proximal nail, discharge to a healthcare facility, and no osteoporotic treatment at discharge. Protective factors against mortality in the univariate analysis were surgical treatment by an experienced surgeon, management without an arthroplasty, allowing full weightbearing, mobilization in the first 48 hours postoperatively, and geriatric involvement. Risk factors for mortality in the multivariate analysis were cognitive impairment (Pfeiffer's questionnaire) (hazard ratio (HR) 1.14 (95% CI 1.05 to 1.23), p = 0.002), age-adjusted CCI (HR 1.18 (95% CI 1.07 to 1.30), p = 0.001), and antiaggregant or anticoagulant medication at admission (HR 2.00 (95% CI 1.19 to 3.38), p = 0.009). Haemoglobin level at admission was protective against mortality (HR 0.85 (95% CI 0.74 to 0.97), p = 0.018). Mortality in FPIFs occurs mainly within the first six months of follow-up. Early co-management and clinical optimization, particularly targeting frail older patients, is crucial in reducing mortality following these fractures.

Osteoporosis in Older Men: Informing Patient Management and Improving Health-Related Outcomes.

Osteoporosis has been usually considered a female disease, generally causing more fracture risk and complications in adult and older women compared to older men. While vertebral fractures occur in a small proportion of men during middle age, men generally fracture about 10years later than women, with significant increases in fracture risk after about age 75. Independent of age, men experiencing fragility fractures have a higher risk of life-threatening events compared to women, but the risk of secondary fragility fracture overlaps between men and women. Often, male osteoporosis recognizes the overlap between secondary causes and primary osteoporosis risk factors. Assessment through physical examination, history, and laboratory tests is recommended, with dual-energy X-ray absorptiometry of bone density being the preferred diagnostic test for osteoporosis in men. A treatment program should include awareness of diet and vitamin D status, fall risk reduction, and pharmaceutical therapy. Medications that are fracture-reducing in older women should also achieve fewer fractures in older men; however, there is a paucity of studies in men with the primary outcome of fracture risk reduction. Most older men with osteoporosis should be treated with oral or intravenous bisphosphonates, denosumab especially when on androgen deprivation therapy, and initial anabolic treatment should be considered for men at very high risk of fracture. This review summarizes the main features of osteoporosis and fragility fractures in men and reports findings from the available pharmacological and non-pharmacological studies conducted in men.

Fracture characteristics and functional outcomes for Schatzker V/VI bicondylar tibial plateau fractures with a separate tubercle fragment: a comparative study.

A separate tibial tubercle fragment (TF) is found in up to half of all bicondylar tibial plateau (BTP) fractures. Adequate healing of the TF is required to reconstitute the extensor mechanism of the knee. The purpose of this study was to compare outcomes after surgical fixation of BTP fractures with and without a TF. Retrospective comparative study of adult patients undergoing open reduction internal fixation (ORIF) of a Schatzker V/VI BTP fracture at two Level 1 trauma centers. Primary outcomes were patient-reported outcomes as assessed by the PROMIS Physical Function (PF) score and EQ-5D-3L. Secondary outcomes included rates of infection, reoperation, and nonunion. Patient demographics, fracture characteristics, and outcomes were compared for patients with and without a TF. 189 patients (mean follow-up 8.1 yrs) were included. 55 patients (29%) had a separate TF. There was no significant difference in PROMIS PF (48.1 vs 47.5, p = 0.45) or EQ-5D-3L scores (0.82 vs 0.83, p = 0.32) between patients with and without a separate tubercle fragment.Patients with a TF had more open fractures (16% vs 5%, p = 0.02) and high energy injuries (66% vs 49%, p = 0.03).There was no significant difference in the rates of deep infection (15% vs 8%, p = 0.19) or unplanned reoperation (23% vs 13%, p = 0.09). There were more nonunions in the TF group (11% vs 2%, p = 0.02) but only two involved the tubercle fragment. In this comparative study, the presence of a TF did not portend a worse functional outcome for patients with a healed fracture. Rates of open fracture and high energy mechanism of injury were significantly higher in the TF group.. Surgeons should be aware that a separate TF may indicate a more severe injury. More studies are needed to determine whether the presence of a TF is associated with higher complication rates.

Clinical and Functional Outcomes of Peri-Implant Fractures Associated with Short Proximal Femur Nails: Prevention Strategies and Key Insights.

Background: Hip fractures are prevalent among the elderly and impose a significant burden on healthcare systems due to the associated high morbidity and costs. The increasing use of intramedullary nails for hip fracture fixation has inadvertently introduced risks; these implants can alter bone elasticity and create stress concentrations, leading to peri-implant fractures. The aim of this study is to investigate the outcomes of peri-implant hip fractures, evaluate the potential causes of such fractures, determine the type of treatment provided, assess the outcomes of said treatments, and establish possible improvement strategies. Methods: We conducted a retrospective observational study on 33 patients with peri-implant hip fractures (PIFs) who underwent surgical management at Río Hortega University Hospital from 2010 to 2022. The collected data included demographics, initial fracture characteristics, the peri-implant fracture classification, implant details, surgical outcomes, functional scores, and complications. Functional capacity was evaluated using the Parker Mobility Score (PMS). Results: The cohort (91% female, mean age 87.6 years) included 34 peri-implant fractures. The mean time from the initial fracture to the PIF was 47.2 months (nine patients developed PIFs within 2 months). Most fractures (76%) were managed with implant removal and the insertion of a long intramedullary nail, with cement augmentation in 31% of cases. The mean surgical time was 102 min, and the average hospital stay was 9.6 days. Postoperative complications occurred in 27%, with a perioperative mortality rate of 9%. Functional capacity showed a significant decline, with an average PMS loss of 4.16 points. Mortality at one year post-PIF was 36%, rising to 83% at five years. Radiographic consolidation was observed in 72% of cases at an average of 6.04 months, though 24% of patients died before consolidation. Statistically significant correlations were found for PMS pre-index fracture (PMS1: r = 0.354, p < 0.05), pre-PIF (PMS2: r = 0.647, p < 0.001), and post-PIF (PMS3: r = 0.604, p < 0.001). Conclusions: Peri-implant hip fractures present complex challenges due to their surgical difficulty and impact on patient mobility and survival. Successful management requires individualized treatment based on fracture type, implant positioning, and patient factors. These findings underscore the need for preventive measures, particularly in implant choice and techniques like overlapping and interlocking constructs, to minimize the secondary fracture risk.

Fracture behavior of NiNb and NiNbP bulk metallic glasses

While it is known that phosphorous additions enhance the hardness, strength, and glass forming ability of NiNb(P) bulk metallic glasses, nothing is known about the trade-offs regarding the fracture characteristics. The fracture toughness and bending deformation behavior of Ni62Nb38 and Ni59.2Nb38.8P2 BMGs were studied, both of which have been reported to have very high compressive yield strength near 3GPa. The binary NiNb BMG exhibited ~4% plastic bending strain and a precracked fracture toughness of KQ = 50MPa√m which gives an excellent combination of strength and toughness relative to other engineering materials. With the addition of 2at.% phosphorus, the glass forming ability was maximized, but the BMG was hardened and embrittled, fatigue precracking was no longer possible, and micronotched toughness values, which should overestimate the precracked fracture toughness, were in the range of KQ = 19 − 26MPa√m. Additionally, a progressive hardening and bending embrittlement was observed for intermediate P additions of 1 and 1.5at.% phosphorus. Transmission electron microscopy revealed larger medium range order clusters in the relatively softer NiNb BMG which were thought to contribute to easier shear transformations and plastic deformation by shear banding.

Effects of rapid infrared radiation heating on the warping deformation and mechanical properties of selective laser melted Co-Cr dental alloy.

Infrared radiation heating (IRH) technology has been innovatively applied to the annealing of selective laser melted (SLM) cobalt chromium (Co-Cr) frameworks. However, previous studies have not reported the effects of IRH on the warping deformation and mechanical properties of these frameworks. The purpose of this in vitro study was to investigate the effects of IRH on the warping deformation and mechanical properties of dental SLM Co-Cr alloy and to evaluate its potential applications in dental restorations. Two types of specimens, bone-shaped tensile specimens and warping deformation specimens (cantilever beam structures), were fabricated by SLM, followed by annealing using IRH and general furnace heating (GFH). The specimens were divided into 4 groups (n=6) based on the applied heat treatment method and build direction (IRH-XY; IRH-Z; GFH-XY; GFH-Z). The cantilever beam support structure of the warping deformation specimen was cut using wire cutting, and the warping deformation was measured using a digital image correlation optical extensometer. Tensile tests were used to evaluate mechanical properties, with the fracture characteristics being observed using a scanning electron microscope (SEM). A micro-Vickers hardness tester was used to measure the microhardness. The microstructures were analyzed using a metallographic microscope. All data were analyzed using a 1-way ANOVA and the Tukey Honestly Significant Difference test (α=.05). The surfaces of the SLM Co-Cr warping deformation specimens treated with IRH showed slight oxidation, while those treated with GFH exhibited a dark black appearance. No significant difference was found in deformation between the IRH group (0.412 ±0.039 mm) and the GFH group (0.379 ±0.070 mm) (P>.05). The elongation of the longitudinally built specimens was significantly higher than that of their transversely built counterparts (P<.05), while the yield strength showed an opposite trend. The longitudinally built specimens demonstrated ductile fracture characteristics, while the transversely built specimens displayed quasi-cleavage fractures. The specimens treated with IRH exhibited comparable tensile strength and microhardness with the GFH-treated specimens, with no statistically significant differences (P>.05). IRH treatment resulted in finer grains in the SLM Co-Cr alloy. Many fine second-phase particles precipitated from the matrix in the longitudinally built specimens, while few were observed in the transversely built specimens. The SLM Co-Cr specimens treated with IRH achieved comparable warping deformation and mechanical properties with those of the GFH-treated specimens. The IRH technology holds great potential for application to dental restorations.

Predictor of diplopia in pure orbital blowout fracture: A 14-year retrospective analysis.

Orbital fractures are common among maxillofacial injuries. The primary objective of this study was to investigate the clinical and radiographic characteristics of pure orbital blowout fractures (OBFs) and their association with post-traumatic diplopia. The secondary objective was to identify predictors of diplopia in pure OBFs. This retrospective cross-sectional study analysed the clinical records and computed tomography (CT) data of patients with pure OBFs, treated between 1st January 2008 and 28th February 2022 at a single tertiary trauma centre in Klang Valley, Kuala Lumpur, Malaysia. Data collected included demographic characteristics and the aetiology of OBFs. Specific factors such as fracture site, size, type, and soft tissue involvement were assessed using CT images, which were converted to DICOM format and analysed with the OsiriX v4.1.2 software. Diplopia was measured using the Hess area ratio percentage (HAR%). The analysis included records of 70 patients. Motor vehicle accidents (MVAs) accounted for 61.4 % of pure OBFs. The largest fracture observed involved both the orbital floor and the medial wall, with a mean size of 6.40 ± 3.05 cm². Among the patients, 41.6 % had Type 3 fractures, and 50 % (n = 35) had 2-point muscle-soft tissue contact. Fracture size, site, type, and muscle contact were all significantly associated with HAR92 % (p < 0.05). Logistic regression revealed that Type 3 fracture was the significant predictor of diplopia (HAR < 92 %), with an odds ratio of 19.80 (95 % CI: 5.76-68.07, p < 0.001). Fracture site, size, type, and muscle involvement were important factors associated with diplopia. Among these, Type 3 fractures were identified as the primary predictor of HAR < 92 %.

Fracture and fatigue characteristics of monodomain and polydomain liquid crystal elastomers.

Liquid crystal elastomers (LCEs), a class of elastomers combining liquid crystals with a polymer network, have garnered significant interest for applications in the field of soft robotics. However, the fracture and fatigue characteristics of LCEs remain poorly understood. This study presents a comprehensive investigation into the fracture and fatigue characteristics of LCEs, focusing on polydomain and monodomain variants subjected to different loading directions. The fracture energy (also called toughness) and fatigue threshold of polydomain and monodomain LCEs were quantitatively measured and compared with selected elastomers. Our experimental results demonstrate that polydomain LCEs exhibit superior fracture energy and fatigue threshold compared to monodomain LCEs. Within the monodomain category, LCEs subjected to parallel loading exhibit larger fracture energy than those under vertical loading, while their fatigue thresholds remain comparable. These findings enhance our understanding of the deformation and failure characteristics of LCEs, which are crucial for their applications in various fields.

Mechanical property and fracture characteristics of carbon fiber reinforced aluminum matrix composites prepared by friction stir welding

Mechanical property and fracture characteristics of carbon fiber reinforced aluminum matrix composites prepared by friction stir welding

Numerical investigation of multiphase flow through self-affine rough fractures

Multiphase flow through fractures has great significance in subsurface energy recovery and gas storage applications. Different fracture and flow properties affect flow through a fracture which is difficult to control in laboratory experiments. Here, we perform lattice Boltzmann simulations in an ensemble of synthetically generated fractures. Drainage simulations are performed at different capillary numbers, wettability, and viscosity ratios. We track the invading front and quantify breakthrough saturations and show that roughness and wettability have a strong effect on fluid invasion through a complex fracture. Invading a more viscous fluid results in more stable displacement regardless of the capillary number while at very low capillary numbers, fluid migration is dependent on the inherent structure of the fracture. We develop a fluid displacement phase diagram in a single rough fracture and compare our results from that in the literature. Finally, we extend the phase diagrams across multiple fractures and demonstrate the importance of natural fracture features of roughness and wettability in identifying stable versus unstable displacement regimes during multiphase flow through rough fractures. Our work presents an end-to-end numerical pathway for testing on experimental data and expanding numerical data sets for testing combinations of different physical phenomenon and make valuable predictions on fluid flow through rough fractures.

The Influence of Reinforcement Size and Shape on the Mechanical Properties of Composites

Abstract: In the present work the effects of size and shape of reinforcements on the mechanical properties of composite material is discussed in detail Since reinforcements have a dominant control on mechanical properties such as, tensile strength, stiffness, toughness and fracture resistance. This work comprehensively assesses how the size and the shape of reinforcements, which can be nano, micro and macroscopic, and can be fibers, particles, or platelets, affect the behaviour of the resulting composites. Both numerical and experimental approaches were used to investigate the interface adhesion, stress profile and fracture characteristics as influenced by the kind of reinforcements. Specific outcomes suggest that the use of nano-sized reinforcements results in enhanced values of toughness and thermal stability, when compared with the use of micro- and macro-sized reinforcements of glass fibers in epoxy composites, which in turn results in improved tensile strength and bulk mechanical stability. Reinforcement shape was also identified as playing a significant part; continuous fibers provided the best load-carrying capability, spherical particles uniform stress distribution, while platelet strengthened impact strength of the composite. In addition, the study on the hybrid reinforcement systems revealed the interaction and cooperation of different reinforcement types to design composite properties for certain industries. The findings of the current study offer corollary guidelines on the development high-performance composites with enhanced mechanical features and fathom the innovative research solutions for the existing flaws such as testing methodologies and bio- spheres reinforcements.

Decreased Muscle Strength and Quality as Characteristics of Elderly Heart Failure and Hip Fractures in Patients with Sarcopenia

Decreased Muscle Strength and Quality as Characteristics of Elderly Heart Failure and Hip Fractures in Patients with Sarcopenia