Introduction: Proximal femoral nail is a better choice of implant for the treatment of an unstable trochanteric fracture, however it is associated with screw migration and cutout because of greater trochanteric commin...Introduction: Proximal femoral nail is a better choice of implant for the treatment of an unstable trochanteric fracture, however it is associated with screw migration and cutout because of greater trochanteric comminution and coronal split. This study is to evaluate the results of Trochanteric Buttress Plate (TBP) combined with PFN in an unstable IT fractures for buttressing lateral wall and reinforcing fixation. Materials and Methods: We carried out a consecutive study of 32 patients of Unstable intertrochanteric fracture femur with lateral wall comminution. It was studied at Ashwini Sahakari Rugnalaya and Sanshodhan Kendra Solapur India and Government medical college Chandrapur India from April-2015 to December-2017 using innovative Trochanteric buttress plate along with PFN. Eighteen male and fourteen female in the age group of 55 to 80 years were included in the study. There were 26 cases of A3 and six cases of A2 were fixed by PFN combined with trochanteric buttress plate to augment the comminuted lateral wall. Results: The bone healing is observed in all the cases in the mean period of 12.6 weeks. Four patients developed complications, including lateral migration of neck screws (n = 2), superficial infection (n = 2). Patients were followed up for a mean of 10.6 months. At the end of follow-up the Salvati and Wilson hip function was 36 (out of 40) in 87.5% of patients [twenty eight patients]. The clinical, radiological and functional outcomes were found to be satisfactory. Conclusion: The stabilization of lateral trochanteric wall with trochanteric buttress plate restores anatomy, increases the stability of construct and prevents inherent complication of screw migration and cutout.展开更多
Radial nerve injuries in displaced extension-type supracondylar humeral fractures in children are well known. Entrapment in fracture of radial nerve is uncommon and rarely evocated in literature. We report two similar...Radial nerve injuries in displaced extension-type supracondylar humeral fractures in children are well known. Entrapment in fracture of radial nerve is uncommon and rarely evocated in literature. We report two similar cases in the mechanism of injury, the clinical findings and the treatment and propose therapeutic guidelines.展开更多
BACKGROUND In pediatric age group patients(<18 years old)treated operatively for distal radius/both bone fractures extending imaging beyond the initial postoperative period-particularly in uncomplicated cases-appea...BACKGROUND In pediatric age group patients(<18 years old)treated operatively for distal radius/both bone fractures extending imaging beyond the initial postoperative period-particularly in uncomplicated cases-appears to provide limited additional benefit.AIM To determine the necessary number of follow-up X-rays to use resources efficiently.METHODS Participants included in this study are pediatric age group patients who were treated operatively for distal radius/both bone fractures and were identified from a prospected collected data from the operating room database between the years 2009 and 2017.The data in the study included patients who had distal radius fractures and underwent fixation surgery(n=88).RESULTS When assessing the difference in the odds of conducting 1 or less X-ray compared to 2 or more X-rays in regard to the type of fixation,the only significant difference is the closed reduction fixation method.Patients who underwent closed reduction method procedure have significantly lower odds of having 2 more X-rays compared to those who didn’t have closed reduction method.Open reduction,internal fixation,and other fixation methods(close reduction and internal fixation,debridement,or epiphysiodesis)have higher odds of having two or more X-rays compared to patients who did not receive these methods;however,these odds are not statistically significant.CONCLUSION The findings of this study reveal notable absence of a statistically significant association between the frequency of postoperative X-rays and the outcome of children with distal radius fractures.展开更多
Prepulse combined hydraulic fracturing facilitates the development of fracture networks by integrating prepulse hydraulic loading with conventional hydraulic fracturing.The formation mechanisms of fracture networks be...Prepulse combined hydraulic fracturing facilitates the development of fracture networks by integrating prepulse hydraulic loading with conventional hydraulic fracturing.The formation mechanisms of fracture networks between hydraulic and pre-existing fractures under different prepulse loading parameters remain unclear.This research investigates the impact of prepulse loading parameters,including the prepulse loading number ratio(C),prepulse loading stress ratio(S),and prepulse loading frequency(f),on the formation of fracture networks between hydraulic and pre-existing fractures,using both experimental and numerical methods.The results suggest that low prepulse loading stress ratios and high prepulse loading number ratios are advantageous loading modes.Multiple hydraulic fractures are generated in the specimen under the advantageous loading modes,facilitating the development of a complex fracture network.Fatigue damage occurs in the specimen at the prepulse loading stage.The high water pressure at the secondary conventional hydraulic fracturing promotes the growth of hydraulic fractures along the damage zones.This allows the hydraulic fractures to propagate deeply and interact with pre-existing fractures.Under advantageous loading conditions,multiple hydraulic fractures can extend to pre-existing fractures,and these hydraulic fractures penetrate or propagate along pre-existing fractures.Especially when the approach angle is large,the damage range in the specimen during the prepulse loading stage increases,resulting in the formation of more hydraulic fractures.展开更多
BACKGROUND Postoperative delirium(POD)is a prevalent complication,particularly in elderly patients with hip fractures(HFs).It significantly affects recovery,length of hospital stay,healthcare costs,and long-term outco...BACKGROUND Postoperative delirium(POD)is a prevalent complication,particularly in elderly patients with hip fractures(HFs).It significantly affects recovery,length of hospital stay,healthcare costs,and long-term outcomes.Existing studies have investigated risk factors for POD,but most are limited by single-factor analyses or small sample sizes.This study systematically determines independent risk factors using large-scale data and machine learning techniques and develops a validated nomogram model to support early prediction and management of POD.AIM To investigate POD incidence in elderly patients with HF and the independent risk factors,according to which a nomogram prediction model was developed and validated.METHODS This retrospective study included elderly patients with HF who were surgically treated in Dongying People’sHospital from April 2018 to April 2022. The endpoint event includes POD. They were categorized into themodeling and validation cohorts in a 7:3 ratio by randomization. Both cohorts were further classified into thedelirium and normal (non-delirium) groups according to the presence or absence of the endpoint event. Theincidence of POD was calculated, and logistic multivariate analysis was conducted to determine the independentrisk factors. The calibration curve and the Hosmer-Lemeshow test as well as the net benefit threshold probabilityinterval by the decision curve were utilized to statistically validate the accuracy of the nomogram predictionmodel, developed according to each factor’s influence intensity.RESULTSThis study included 532 elderly patients with HF, with an overall POD incidence of 14.85%. The comparison ofbaseline data with perioperative indicators revealed statistical differences in age (P < 0.001), number of comorbidities(P = 0.042), American Society of Anesthesiologists grading (P = 0.004), preoperative red blood cell(RBC) count (P < 0.001), preoperative albumin (P < 0.001), preoperative hemoglobin (P < 0.001), preoperativeplatelet count (P < 0.001), intraoperative blood loss (P < 0.001), RBC transfusion of ≥ 2 units (P = 0.001), andpostoperative intensive care unit care (P < 0.001) between the delirium and non-delirium groups. The participantswere randomized to a training group (n = 372) and a validation group (n = 160). A score-risk nomogram predictionmodel was developed after screening key POD features using Lasso regression, support vector machine, and therandom forest method. The nomogram showed excellent discriminatory capacity with area under the curve of0.833 [95% confidence interval (CI) interval: 0.774-0.888] in the training group and 0.850 (95%CI: 0.718-0.982) in thevalidation group. Calibration curves demonstrated good agreement between predicted and actual probabilities,and decision curve analysis confirmed clinical net benefits within risk thresholds of 0%-30% and 0%-36%, respectively.The model has strong accuracy and clinical utility for predicting the risk of POD.CONCLUSIONThis study reveals cognitive impairment history, American Society of Anesthesiologists grade of > 2, RBCtransfusion of ≥ 2 units, postoperative intensive care unit care, and preoperative hemoglobin level as independentrisk factors for POD in elderly patients with HF. The developed nomogram model demonstrates excellent accuracyand stability in predicting the risk of POD, which is recommended to be applied in clinical practice to optimizepostoperative management and reduce delirium incidence.展开更多
BACKGROUND Traumatic injuries,such as falling,car accidents,and crushing mostly cause spinal fractures in young and middle-aged people,and>50%of them are thoracolumbar fractures.This kind of fracture is easily comb...BACKGROUND Traumatic injuries,such as falling,car accidents,and crushing mostly cause spinal fractures in young and middle-aged people,and>50%of them are thoracolumbar fractures.This kind of fracture is easily combined with serious injuries to peripheral nerves and soft tissues,which causes paralysis of the lower limbs if there is no timely rehabilitation treatment.Young patients with thoracolumbar fractures find it difficult to recover after the operation,and they are prone to depression,low self-esteem,and other negative emotions.AIM To investigate the association between anxiety,depression,and social stress in young patients with thoracolumbar spine fractures and the effect on rehabilitation outcomes.METHODS This study retrospectively analyzed 100 patients admitted to the orthopedic department of Honghui Hospital,Xi’an Jiaotong University who underwent thoracolumbar spine fracture surgery from January 2022 to June 2023.The general data of the patients were assessed with the Hamilton anxiety scale(HAMA),Hamilton depression scale(HAMD),life events scale,and social support rating scale(SSRS)to identify the correlation between anxiety,depression scores,and social stress and social support.The Japanese Orthopedic Association(JOA)was utilized to evaluate the rehabilitation outcomes of the patients and to analyze the effects of anxiety and depression scores on rehabilitation.RESULTS According to the scores of HAMD and HAMA in all patients,the prevalence of depression in patients was 39%(39/100),and the prevalence of anxiety was 49%(49/100).Patients were categorized into non-depression(n=61)and depression(n=39),non-anxiety(n=51),and anxiety(n=49)groups.Statistically significant differences in gender,occupation,Pittsburgh Sleep Quality Index(PSQI)score,and monthly family income were observed between the non-depression and depression groups(P<0.05).A significant difference in occupation and PSQI score was found between the non-anxiety and anxiety groups.Both depression(r=0.207,P=0.038)and anxiety scores(r=0.473,P<0.001)were significantly and positively correlated with negative life events.The difference in negative life event scores as well as SSRS total and item scores was statist-ically significant between patients in the non-depression and depression groups(P<0.05).The difference between the non-anxiety and anxiety groups was statistically significant(P<0.05)in the negative life event scores as well as the total SSRS scores.Additionally,JOA scores were significantly lower in both anxious and depressed patients.CONCLUSION Young patients with thoracolumbar fractures are prone to anxiety and depression.Patients’anxiety and depression are closely associated with social pressure,which reduces the life pressure of young patients with thoracolumbar fractures,enhances social support,and improves the psychology of anxiety and depression.,which affects patients’recovery.展开更多
Hydraulic fracturing is a crucial technique for efficient development of coal reservoirs.Coal rocks typically contain a high density of natural fractures,which serve as conduits for fracturing fluid.Upon injection,the...Hydraulic fracturing is a crucial technique for efficient development of coal reservoirs.Coal rocks typically contain a high density of natural fractures,which serve as conduits for fracturing fluid.Upon injection,the fluid infiltrates these natural fractures and leaks out,resulting in complex fracture morphology.The prediction of hydraulic fracture network propagation for coal reservoirs has important practical significance for evaluating hydraulic fracturing.This study proposes a novel inversion method for predicting fracture networks in coal reservoirs,explicitly considering the distribution of natural fractures.The method incorporates three distinct natural fracture opening modes and employs a fractal probability function to constrain fracture propagationmorphology.Based on thismethod,the study compares hydraulic fracture networkmorphologies in coal reservoirs with andwithout the presence of natural fractures.Theresults showthatwhile both reservoir types exhibitmulti-branch fracture networks,reservoirs containing natural fractures demonstrate greater branching and a larger stimulated reservoir volume(SRV).Additionally,the study employs a fractal dimension calculation method to quantitatively describe the geometric distribution characteristics of fractures.The analysis reveals that the geometry and distribution of natural fractures,as well as reservoir geological parameters,significantly influence the fracture networkmorphology and fractal dimension.The contact angle between natural and hydraulic fractures affects propagation direction;specifically,when the contact angle isπ/2,the fractal dimension of the hydraulic fracture network is maximized.Moreover,smaller lengths and spacings of natural fracture led to higher fractal dimensions,which can significantly increase the SRV.The proposed method offers an effective tool for evaluating the hydraulic fracturing of coal reservoirs.展开更多
According to World Health Organization,one in six people will be older than 60 by 2030.The rising life expectancy is anticipated to contribute to a subsequent increase of geriatric fractures worldwide.Osteosarcopenia,...According to World Health Organization,one in six people will be older than 60 by 2030.The rising life expectancy is anticipated to contribute to a subsequent increase of geriatric fractures worldwide.Osteosarcopenia,which is the coexistence of osteoporosis and sarcopenia,greatly affects older people.Recent studies have tried to identify the prevalence of osteosarcopenia in older populations as well as its correlation with fragility fractures such as hip fractures.The latter pose a major burden on both health loss and costs worldwide.Increasing amount of evidence suggests that osteosarcopenia in patients with hip fractures contributes to higher rates of mortality and complications.At the same time,research focuses on the molecular basis of the interplay between osteoporosis and sarcopenia by utilizing genomic or proteomic approaches.These promising studies could reveal potential preventive or diagnostic biomarkers to optimize the management of osteosarcopenia in hip fractures patients.The fact that bones and muscle can also function as endocrine organs further highlights the complex relationship between osteoporosis and sarcopenia,underscoring the need for a better understanding of the role of myokines and osteokines in osteosarcopenia.Finally,the impact of osteosarcopenia on pain management and rehabilitation after hip fracture surgery,requires further assessment.展开更多
Prophylactic fixation(ProFix)of the proximal femur in elderly patients with osteoporosis presents a forward-thinking approach to preventing debilitating fractures and their associated complications.By addressing fract...Prophylactic fixation(ProFix)of the proximal femur in elderly patients with osteoporosis presents a forward-thinking approach to preventing debilitating fractures and their associated complications.By addressing fracture risk before an injury occurs,ProFix has the potential to enhance patient outcomes,promote long-term mobility,and reduce healthcare costs.Early intervention in individuals at high risk can significantly lower hospital admissions,shorten recovery periods,and preserve independence,mitigating challenges such as chronic pain and reduced life expectancy.Given the high prevalence of undiagnosed osteoporosis,prioritising early risk assessment and targeted prevention is essential.Advancements in minimally invasive surgical techniques and safer anaesthesia methods further support ProFix as a feasible and effective strategy to decrease fracturerelated morbidity,improve overall patient well-being,and optimise the use of healthcare resources.This opinion review details the evidence supporting this concept,its efficacy,the challenges in its implementation,and a strategic plan for future implementation.展开更多
BACKGROUND Radial head fractures constitute approximately one-third of all elbow fractures,significantly impacting the young and active population.While open reduction and internal fixation is the preferred treatment ...BACKGROUND Radial head fractures constitute approximately one-third of all elbow fractures,significantly impacting the young and active population.While open reduction and internal fixation is the preferred treatment for displaced fractures,its high complication rate in comminuted fractures has led to the increasing use of radial head arthroplasty(RHA).RHA provides improved functional outcomes with fewer complications,yet its long-term efficacy remains a topic of debate.AIM To evaluate the functional outcomes of patients undergoing RHA with a modular metallic prosthesis for comminuted Mason type III and IV radial head fractures.METHODS A prospective and retrospective hospital-based study was conducted at Dayanand Medical College and Hospital,Ludhiana over 32 months(January 2021-August 2023).A total of 26 patients with Mason type III and IV fractures were included,with six retrospective and 20 prospective cases.Functional outcomes were assessed using the Mayo Elbow Performance Score(MEPS),elbow range of motion,pain via Visual Analog Scale,and activities of daily living at immediate postoperative,three-month,and six-month follow-ups.RESULTS MEPS at 6 months follow up for 4 cases(15.38%)had good scores,and 22 cases(84.62%)had excellent scores,with a mean±SD of 97.31±6.67.Comparisons showed significant improvement from immediate post-operative to 3 months(P<0.0001),from immediate post-operative to 6 months(P<0.0001),and between 3 months and 6 months(P<0.0001).None of the patients had elbow instability after radial head replacement and 22 cases(84.62%)had no complications,while 3 cases(11.54%)had a stiff elbow,and 1 case(3.85%)had heterotopic ossification.CONCLUSION RHA is an effective treatment for comminuted radial head fractures,providing stable elbow function with minimal complications.展开更多
A DFN-DEC(discrete fracture network-distinct element code)method based on the MATLAB platform is developed to generate heterogeneous DFN.Subsequently,the effects of the spatial variability(the meanμand the standard d...A DFN-DEC(discrete fracture network-distinct element code)method based on the MATLAB platform is developed to generate heterogeneous DFN.Subsequently,the effects of the spatial variability(the meanμand the standard deviationσ)of the geometric properties(i.e.,the fracture dip D,the trace length T and the spacing S)of both the gently-dipping(denoted with 1)and the steeply-dipping(denoted with 2)fractures on the stability of granite slope are investigated.Results indicate that the proposed DFN-DEC method is robust,generating fracture networks that resemble reality.In addition,the spatial variability of fracture geometry,influencing the structure of granite slope,plays a significant role in slope stability.The mean stability of the slope decreases with the increase ofμ_(D_(1))(the mean of gently-dipping fracture dip),σ_(D_(2))(the mean of steeply-dipping fracture dip),μ_(T_(1))(the mean of gently-dipping fracture trace length),μ_(T_(2))(the mean of steeply-dipping fracture trace length),σ_(T_(1))(the standard deviation of gently-dipping fracture trace length),σ_(T_(2))(the standard deviation of steeply-dipping fracture trace length),and the decrease ofσ_(D_(1))(the standard deviation of gently-dipping fracture dip),μ_(D_(2))(the standard deviation of steeply-dipping fracture dip),μ_(S_(1))(the mean of gently-dipping fracture spacing)andμ_(S_(2))(the mean of steeply-dipping fracture spacing).Among them,μ_(T_(1)),μ_(D_(1))andμ_(S_(1))have the major impact.When the fracture spacing is large,the variability in the fracture geometry becomes less relevant to slope stability.When within some ranges of the fracture spacing,the spatial varying of dips can increase the slope stability by forming an interlaced structure.The results also show that the effects of the variability of trace length on slope stability depend on the variability of dip.These findings highlight the importance of spatial variability in the geometry of fractures to rock slope stability analysis.展开更多
BACKGROUND Supracondylar humeral fractures(SCHF)are the second most common fractures in childhood and can lead to short-and long-term complications.Despite their prevalence,the anatomical factors that predispose child...BACKGROUND Supracondylar humeral fractures(SCHF)are the second most common fractures in childhood and can lead to short-and long-term complications.Despite their prevalence,the anatomical factors that predispose children to SCHF remain unclear.This study aimed to determine whether there are significant morpho-logical differences in the elbow by comparing the radiographic angular measure-ments of the contralateral elbows of patients with SCHF to those of patients with distal radius fractures(DRF)and a healthy control group.We sought to explore if these morphological variations contribute to the occurrence of SCHF.Radiographs of 78 SCHF patients were analyzed for angular measurements of the contralateral elbow.Two control groups were used:98 healthy children and 40 patients with DRF.Angular measurements included Baumann angle(BA),hu-meroulnar angle(HUA),humerus metaphysis-diaphysis angle(HMDA),humerus shaft-condylar angle(HSCA),and lateral capitellohumeral angle.Only BA,HUA,and HMDA were measured in the DRF group.Statistical analysis was performed to compare differences among groups.RESULTS Significant differences were found in elbow measurements between SCHF and control groups(P<0.05).However,the mean values for all groups fell within the ranges described in the literature.CONCLUSION While statistically significant differences were found in elbow morphology between SCHF patients and controls,these differences don't translate into clinically meaningful morphological deviations.展开更多
To accurately analyze proppant transport in rough intersecting fractures and elucidate the interaction mechanisms among liquid,particles,and rough walls,this study reconstructed a numerical model of fractures in inhom...To accurately analyze proppant transport in rough intersecting fractures and elucidate the interaction mechanisms among liquid,particles,and rough walls,this study reconstructed a numerical model of fractures in inhomogeneous reservoirs with varying brittleness index(BI).Various auto-correlation Gaussian rough fracture models were created using Matlab to assess roughness through the fractal dimension method.This research innovatively combined Boolean operations to establish three-dimensional rough fracture models,incorporating(Computational Fluid Dynamics)CFD-DEM(Discrete Element Method)with a bidirectional method for cosimulation.The proppant transport in fractures was categorized into three zones based on the difference in the turbulent kinetic energy.Artificially induced fracture roughness increases fluid retention and turbulence,causing plugging effects and limiting proppant flow into branch fractures.Additionally,compared with the superior deposition and significant support effects of the spherical proppant,the low-sphericity proppant traveled farther under fracturing fluid,inducing more pronounced plugging near curved fracture intersections;the variation in fracture intersection angles primarily impacted the wall shear stress within the flow field,indicating smaller angles led to higher shear energy at the intersection.Compared with the intersection angle of 30°,the height and area deposited in the 90 branch fracture increased by 52.25%and 65.33%,respectively:notably,injecting proppant from smaller to larger particles(S:M:L)and a low velocity effectively ensured fracture conductivity near the wellbore at joint roughness coefficient(JRC)≥46 while achieving satis-factory placement in the branch fracture,making it a recommended approach.展开更多
Shale reservoirs are characterized by numerous geological discontinuities,such as bedding planes,and exhibit pronounced heterogeneity across rock layers separated by these planes.Bedding planes often possess distinct ...Shale reservoirs are characterized by numerous geological discontinuities,such as bedding planes,and exhibit pronounced heterogeneity across rock layers separated by these planes.Bedding planes often possess distinct mechanical properties compared to the surrounding rock matrix,particularly in terms of damage and fracture behavior.Consequently,vertical propagation of hydraulic fractures is influenced by both bedding planes and the heterogeneity.In this study,a numerical investigation into the height growth of hydraulic fractures was conducted using the finite element method,incorporating zero-thickness cohesive elements.The analysis explored the effects of bedding planes,toughness contrasts between layers,and variations in in-situ stress across different strata.The results reveal that hydraulic fractures are more likely to propagate along bedding planes instead of traversing them and extending vertically into barrier layers when(1)bedding strength is low,(2)stress contrast between layers is high,and(3)toughness contrast is significant.Furthermore,for a given bedding strength,increased stress contrast or higher toughness contrast between layers elevate hydraulic fracture extension pressure.When a substantial stress difference exists between layers(Lc 0.4),hydraulic=fractures preferentially propagate along bedding planes.Conversely,as bedding strength increases,the propagation distance along bedding planes decreases,accompanied by an amplified horizontal compressive stress field.Notably,when the stress difference is sufficiently small(SD a phenomenon termed“stress rolling”emerges,wherein<-0.2),hydraulic fractures deviate from vertical growth and instead extend along a near-horizontal trajectory.展开更多
Despite extensive research on computational geomechanics and fluid dynamics,accurately simulating convection-diffusion(CD)processes in complex fractured systems remains a significant challenge.This study develops a 3D...Despite extensive research on computational geomechanics and fluid dynamics,accurately simulating convection-diffusion(CD)processes in complex fractured systems remains a significant challenge.This study develops a 3D numerical framework for modelling CD processes in fractured geological media.The framework integrates Darcy's law and Fick's law,considering flux interactions between the matrix and fractures.The meshing strategy generates high-quality grids even in scenarios involving intersecting fractures.Then,a unified numerical scheme for solving the CD system is proposed.The novelties of this work include:(1)The proposed framework enables effective simulation of 3D fractured media,including more complex fractured vuggy media;(2)The numerical method precisely discretizes the CD terms in governing equations;(3)A Non-Orthogonal Correction(NOC)method,combined with an adaptive time integration scheme,is proposed for eliminating errors induced by skewed grids;and(4)The effects of fracture patterns and heterogeneity on flow are thoroughly analysed.The proposed method is validated through benchmark tests,demonstrating the superiority of the NOC method compared to classical methods.Further analysis reveals the evolution characteristics of pressure and concentration,offering insights into the effects of fracture patterns and heterogeneity on flow and diffusion processes.展开更多
BACKGROUND Periprosthetic fractures of the tibia are uncommon complications after total knee arthroplasty(TKA).Therefore,there is still clinical debate regarding the appropriate treatment method.This study presents th...BACKGROUND Periprosthetic fractures of the tibia are uncommon complications after total knee arthroplasty(TKA).Therefore,there is still clinical debate regarding the appropriate treatment method.This study presents the case of a patient with two successive periprosthetic fractures of the tibial shaft treated with revision TKA(rTKA)and intramedullary fixation.CASE SUMMARY A 65-year-old woman was treated for tibial shaft pseudarthrosis after a periprosthetic fracture.The patient underwent rTKA with a tibial component exchange to a long-stemmed implant.At her 1.5-year follow-up visit,partial asymptomatic bone union was noted with no prosthesis loosening.The patient achieved 0°to 120°range of motion and a stable knee,and reported high satisfaction.Improvements were observed in the Western Ontario and McMaster Universities Osteoarthritis Index(WOMAC)from 74 to 17,and in the knee society scores(KSS)from 56 to 91(clinical)and 10 to 80(functional).After 2.5 years,the patient sustained a second fracture below the original site due to low-energy trauma.The rTKA with intramedullary stabilization was performed.One year later,WOMAC and clinical and functional KSS were 15,81,and 80,respectively.Despite tibial shortening and lower limb inequality,the patient remains very satisfied and does not experience any issues with daily activities nor weight-bearing.CONCLUSION There is little consensus in the literature on the management of tibial shaft periprosthetic fractures.Intramedullary stabilization may yield excellent outcomes,but individual case discussion is necessary for rTKA indications.展开更多
Controllable shock wave fracturing is an innovative engineering technique used for shale reservoir fracturing and reformation.Understanding the anisotropic fracture mechanism of shale under impact loading is vital for...Controllable shock wave fracturing is an innovative engineering technique used for shale reservoir fracturing and reformation.Understanding the anisotropic fracture mechanism of shale under impact loading is vital for optimizing shock wave fracturing equipment and enhancing shale oil production.In this study,using the well-known notched semi-circular bend(NSCB)sample and the novel double-edge notched flattened Brazilian disc(DNFBD)sample combined with a split Hopkinson pressure bar(SHPB),various dynamic anisotropic fracture properties of Lushan shale,including failure characteristics,fracture toughness,energy dissipation and crack propagation velocity,are comprehensively compared and discussed under mode Ⅰ and mode Ⅱ fracture scenarios.First,using a newly modified fracture criterion considering the strength anisotropy of shale,the DNFBD specimen is predicted to be a robust method for true mode Ⅱ fracture of anisotropic shale rocks.Our experimental results show that the dynamic mode Ⅱ fracture of shale induces a rougher and more complex fracture morphology and performs a higher fracture toughness or fracture energy compared to dynamic mode Ⅰ fracture.The minimal fracture toughness or fracture energy occurs in the Short-transverse orientation,while the maximal ones occur in the Divider orientation.In addition,it is interesting to find that the mode Ⅱ fracture toughness anisotropy index decreases more slowly than that in the mode Ⅰ fracture scenario.These results provide significant insights for understanding the different dynamic fracture mechanisms of anisotropic shale rocks under impact loading and have some beneficial implications for the controllable shock wave fracturing technique.展开更多
Both the complex geometrical morphology of rough-walled rock fractures and the nonlinearity of fluid flow contribute to resistance in fluid flow through rock fractures.The interactions of the shear-flow process furthe...Both the complex geometrical morphology of rough-walled rock fractures and the nonlinearity of fluid flow contribute to resistance in fluid flow through rock fractures.The interactions of the shear-flow process further complicate the characterisation of flow behaviours in rock fractures.In this study,an improved friction factor model involving both the effects of viscous and inertial forces is presented based on the Forchheimer equation.The model incorporates two key variables,i.e.Reynolds number and relative roughness,which reflect the effects of flow regimes and fracture roughness,respectively.The changes in geometrical parameters induced by shearing are considered,with the peak asperity height predicted through a correlation with post-peak roughness degradation.The hydraulic aperture during shearing is estimated using a suggested equation that accounts for the mobilised contact area ratio and variable aperture distribution.The parametric sensitivity analysis reveals that shear-induced changes in fracture geometry enhance the flow nonlinearity in rock fractures.The model performs well in predicting the friction factor based on two validation criteria.Then,the proposed friction factor model is incorporated into the three-dimensional distinct element code(3DEC)in the form of the Darcy-Weisbach equation.Coupled with the numerically implemented mechanical model and hydraulic aperture prediction model,numerical simulations of coupled shear-flow processes in single rock fractures are conducted.The simulation outcomes are validated through comparison with the experimental results,showing acceptable agreement and demonstrating that the numerical model is capable of accurately evaluating the hydro-mechanical coupling behaviour during the shearing of rock fractures.展开更多
The strike-slip fault system in the central Tarim Craton controls a complex petroleum system with estimated reserves exceeding 1×10^(9)t,the fault-related fractures are important for hydrocarbon accumulation.In t...The strike-slip fault system in the central Tarim Craton controls a complex petroleum system with estimated reserves exceeding 1×10^(9)t,the fault-related fractures are important for hydrocarbon accumulation.In this paper,the basic parameters such as density and width of fractures are counted and classified,and the effects of fractures on reservoirs are analyzed.The results show that:(1)Structural fractures and stylolite were widely developed in Halahatang area and experienced at least three stages of activity based on the infilling materials and crosscutting relationship.(2)Fracture density,width,aperture,and dip angle vary in different wells,but the relationship between the above parameters and the distance to the fault core indicates the fracture differences in the fault damage zone and further provides a method to divide the inner units in the fault damage zone.In addition,oil and gas wells with high production mainly concentrate in the inner unit.(3)The infilling materials and degree of fractures vary.Fractures formed in the early stage are more filled and less open,while the fractures formed in the late stage are relatively less filled and more open.(4)Fractures improve porosity to a certain extent but greatly increase permeability,especially in the inner zone of fault damage zone with large quantity,multiple inclinations,less filling and large width.These features contribute to the formation of a higher-quality reservoir,further improving oil and gas production.This paper provides a quantitative characterization method for the study of strike-slip fault-related fracture-caved reservoirs,and points out that fault damage zone,especially the inner zone of the fault damage zone,is the potential goal for oil and gas exploration.展开更多
Multistage fracturing technology has been used to enhance tight hydrocarbon resource recovery.Determining the proper well spacing and fracturing strategy is crucial for generating a complex fracture network that facil...Multistage fracturing technology has been used to enhance tight hydrocarbon resource recovery.Determining the proper well spacing and fracturing strategy is crucial for generating a complex fracture network that facilitates oil and gas flow in reservoirs.The stress-shadow effect that occurs between multiple wells significantly affects the development of fracture networks in reservoirs.However,the quantification of the stress-shadow effect and its influence on fracture networks has not been satisfactorily resolved because of the difficulties in detecting and identifying fracture propagation and reorientation in reservoirs.In this study,based on the geological information from the Shengli oilfield,we applied a hybrid finite element-discrete element method to analyze engineering-scale three-dimensional fracture propagation and reorientation by altering well spacings and fracturing strategies.The results indicate that the fracturing area generated by the synchronous fracturing scheme is much smaller than those generated by the sequential and alternative schemes.An alternative hydrofracturing scheme is optimal with respect to fracturing area.The stress-blind area was defined to quantify the mechanical disturbance between adjacent wells.Our study improves the understanding of the effect of fracturing schemes on fracture networks and the impact of independent factors contributing to stress-shadow effects.展开更多
文摘Introduction: Proximal femoral nail is a better choice of implant for the treatment of an unstable trochanteric fracture, however it is associated with screw migration and cutout because of greater trochanteric comminution and coronal split. This study is to evaluate the results of Trochanteric Buttress Plate (TBP) combined with PFN in an unstable IT fractures for buttressing lateral wall and reinforcing fixation. Materials and Methods: We carried out a consecutive study of 32 patients of Unstable intertrochanteric fracture femur with lateral wall comminution. It was studied at Ashwini Sahakari Rugnalaya and Sanshodhan Kendra Solapur India and Government medical college Chandrapur India from April-2015 to December-2017 using innovative Trochanteric buttress plate along with PFN. Eighteen male and fourteen female in the age group of 55 to 80 years were included in the study. There were 26 cases of A3 and six cases of A2 were fixed by PFN combined with trochanteric buttress plate to augment the comminuted lateral wall. Results: The bone healing is observed in all the cases in the mean period of 12.6 weeks. Four patients developed complications, including lateral migration of neck screws (n = 2), superficial infection (n = 2). Patients were followed up for a mean of 10.6 months. At the end of follow-up the Salvati and Wilson hip function was 36 (out of 40) in 87.5% of patients [twenty eight patients]. The clinical, radiological and functional outcomes were found to be satisfactory. Conclusion: The stabilization of lateral trochanteric wall with trochanteric buttress plate restores anatomy, increases the stability of construct and prevents inherent complication of screw migration and cutout.
文摘Radial nerve injuries in displaced extension-type supracondylar humeral fractures in children are well known. Entrapment in fracture of radial nerve is uncommon and rarely evocated in literature. We report two similar cases in the mechanism of injury, the clinical findings and the treatment and propose therapeutic guidelines.
文摘BACKGROUND In pediatric age group patients(<18 years old)treated operatively for distal radius/both bone fractures extending imaging beyond the initial postoperative period-particularly in uncomplicated cases-appears to provide limited additional benefit.AIM To determine the necessary number of follow-up X-rays to use resources efficiently.METHODS Participants included in this study are pediatric age group patients who were treated operatively for distal radius/both bone fractures and were identified from a prospected collected data from the operating room database between the years 2009 and 2017.The data in the study included patients who had distal radius fractures and underwent fixation surgery(n=88).RESULTS When assessing the difference in the odds of conducting 1 or less X-ray compared to 2 or more X-rays in regard to the type of fixation,the only significant difference is the closed reduction fixation method.Patients who underwent closed reduction method procedure have significantly lower odds of having 2 more X-rays compared to those who didn’t have closed reduction method.Open reduction,internal fixation,and other fixation methods(close reduction and internal fixation,debridement,or epiphysiodesis)have higher odds of having two or more X-rays compared to patients who did not receive these methods;however,these odds are not statistically significant.CONCLUSION The findings of this study reveal notable absence of a statistically significant association between the frequency of postoperative X-rays and the outcome of children with distal radius fractures.
基金financially supported by,the Fundamental Research Funds for the Central Universities(Grant No.2023QN1064)the China Postdoctoral Science Foundation(Grant No.2023M733772)Jiangsu Funding Program for Excellent Postdoctoral Talent(Grant No.2023ZB847)。
文摘Prepulse combined hydraulic fracturing facilitates the development of fracture networks by integrating prepulse hydraulic loading with conventional hydraulic fracturing.The formation mechanisms of fracture networks between hydraulic and pre-existing fractures under different prepulse loading parameters remain unclear.This research investigates the impact of prepulse loading parameters,including the prepulse loading number ratio(C),prepulse loading stress ratio(S),and prepulse loading frequency(f),on the formation of fracture networks between hydraulic and pre-existing fractures,using both experimental and numerical methods.The results suggest that low prepulse loading stress ratios and high prepulse loading number ratios are advantageous loading modes.Multiple hydraulic fractures are generated in the specimen under the advantageous loading modes,facilitating the development of a complex fracture network.Fatigue damage occurs in the specimen at the prepulse loading stage.The high water pressure at the secondary conventional hydraulic fracturing promotes the growth of hydraulic fractures along the damage zones.This allows the hydraulic fractures to propagate deeply and interact with pre-existing fractures.Under advantageous loading conditions,multiple hydraulic fractures can extend to pre-existing fractures,and these hydraulic fractures penetrate or propagate along pre-existing fractures.Especially when the approach angle is large,the damage range in the specimen during the prepulse loading stage increases,resulting in the formation of more hydraulic fractures.
基金Supported by Wang Zhengguo Foundation for Traumatic Medicine“Sequential Medical Research Special Foundation”,No 2024-XGM05.
文摘BACKGROUND Postoperative delirium(POD)is a prevalent complication,particularly in elderly patients with hip fractures(HFs).It significantly affects recovery,length of hospital stay,healthcare costs,and long-term outcomes.Existing studies have investigated risk factors for POD,but most are limited by single-factor analyses or small sample sizes.This study systematically determines independent risk factors using large-scale data and machine learning techniques and develops a validated nomogram model to support early prediction and management of POD.AIM To investigate POD incidence in elderly patients with HF and the independent risk factors,according to which a nomogram prediction model was developed and validated.METHODS This retrospective study included elderly patients with HF who were surgically treated in Dongying People’sHospital from April 2018 to April 2022. The endpoint event includes POD. They were categorized into themodeling and validation cohorts in a 7:3 ratio by randomization. Both cohorts were further classified into thedelirium and normal (non-delirium) groups according to the presence or absence of the endpoint event. Theincidence of POD was calculated, and logistic multivariate analysis was conducted to determine the independentrisk factors. The calibration curve and the Hosmer-Lemeshow test as well as the net benefit threshold probabilityinterval by the decision curve were utilized to statistically validate the accuracy of the nomogram predictionmodel, developed according to each factor’s influence intensity.RESULTSThis study included 532 elderly patients with HF, with an overall POD incidence of 14.85%. The comparison ofbaseline data with perioperative indicators revealed statistical differences in age (P < 0.001), number of comorbidities(P = 0.042), American Society of Anesthesiologists grading (P = 0.004), preoperative red blood cell(RBC) count (P < 0.001), preoperative albumin (P < 0.001), preoperative hemoglobin (P < 0.001), preoperativeplatelet count (P < 0.001), intraoperative blood loss (P < 0.001), RBC transfusion of ≥ 2 units (P = 0.001), andpostoperative intensive care unit care (P < 0.001) between the delirium and non-delirium groups. The participantswere randomized to a training group (n = 372) and a validation group (n = 160). A score-risk nomogram predictionmodel was developed after screening key POD features using Lasso regression, support vector machine, and therandom forest method. The nomogram showed excellent discriminatory capacity with area under the curve of0.833 [95% confidence interval (CI) interval: 0.774-0.888] in the training group and 0.850 (95%CI: 0.718-0.982) in thevalidation group. Calibration curves demonstrated good agreement between predicted and actual probabilities,and decision curve analysis confirmed clinical net benefits within risk thresholds of 0%-30% and 0%-36%, respectively.The model has strong accuracy and clinical utility for predicting the risk of POD.CONCLUSIONThis study reveals cognitive impairment history, American Society of Anesthesiologists grade of > 2, RBCtransfusion of ≥ 2 units, postoperative intensive care unit care, and preoperative hemoglobin level as independentrisk factors for POD in elderly patients with HF. The developed nomogram model demonstrates excellent accuracyand stability in predicting the risk of POD, which is recommended to be applied in clinical practice to optimizepostoperative management and reduce delirium incidence.
文摘BACKGROUND Traumatic injuries,such as falling,car accidents,and crushing mostly cause spinal fractures in young and middle-aged people,and>50%of them are thoracolumbar fractures.This kind of fracture is easily combined with serious injuries to peripheral nerves and soft tissues,which causes paralysis of the lower limbs if there is no timely rehabilitation treatment.Young patients with thoracolumbar fractures find it difficult to recover after the operation,and they are prone to depression,low self-esteem,and other negative emotions.AIM To investigate the association between anxiety,depression,and social stress in young patients with thoracolumbar spine fractures and the effect on rehabilitation outcomes.METHODS This study retrospectively analyzed 100 patients admitted to the orthopedic department of Honghui Hospital,Xi’an Jiaotong University who underwent thoracolumbar spine fracture surgery from January 2022 to June 2023.The general data of the patients were assessed with the Hamilton anxiety scale(HAMA),Hamilton depression scale(HAMD),life events scale,and social support rating scale(SSRS)to identify the correlation between anxiety,depression scores,and social stress and social support.The Japanese Orthopedic Association(JOA)was utilized to evaluate the rehabilitation outcomes of the patients and to analyze the effects of anxiety and depression scores on rehabilitation.RESULTS According to the scores of HAMD and HAMA in all patients,the prevalence of depression in patients was 39%(39/100),and the prevalence of anxiety was 49%(49/100).Patients were categorized into non-depression(n=61)and depression(n=39),non-anxiety(n=51),and anxiety(n=49)groups.Statistically significant differences in gender,occupation,Pittsburgh Sleep Quality Index(PSQI)score,and monthly family income were observed between the non-depression and depression groups(P<0.05).A significant difference in occupation and PSQI score was found between the non-anxiety and anxiety groups.Both depression(r=0.207,P=0.038)and anxiety scores(r=0.473,P<0.001)were significantly and positively correlated with negative life events.The difference in negative life event scores as well as SSRS total and item scores was statist-ically significant between patients in the non-depression and depression groups(P<0.05).The difference between the non-anxiety and anxiety groups was statistically significant(P<0.05)in the negative life event scores as well as the total SSRS scores.Additionally,JOA scores were significantly lower in both anxious and depressed patients.CONCLUSION Young patients with thoracolumbar fractures are prone to anxiety and depression.Patients’anxiety and depression are closely associated with social pressure,which reduces the life pressure of young patients with thoracolumbar fractures,enhances social support,and improves the psychology of anxiety and depression.,which affects patients’recovery.
基金This study was supported by the Foundation of National Engineering Laboratory for Exploration and Development of Low-Permeability Oil and Gas Fields(2023-015).
文摘Hydraulic fracturing is a crucial technique for efficient development of coal reservoirs.Coal rocks typically contain a high density of natural fractures,which serve as conduits for fracturing fluid.Upon injection,the fluid infiltrates these natural fractures and leaks out,resulting in complex fracture morphology.The prediction of hydraulic fracture network propagation for coal reservoirs has important practical significance for evaluating hydraulic fracturing.This study proposes a novel inversion method for predicting fracture networks in coal reservoirs,explicitly considering the distribution of natural fractures.The method incorporates three distinct natural fracture opening modes and employs a fractal probability function to constrain fracture propagationmorphology.Based on thismethod,the study compares hydraulic fracture networkmorphologies in coal reservoirs with andwithout the presence of natural fractures.Theresults showthatwhile both reservoir types exhibitmulti-branch fracture networks,reservoirs containing natural fractures demonstrate greater branching and a larger stimulated reservoir volume(SRV).Additionally,the study employs a fractal dimension calculation method to quantitatively describe the geometric distribution characteristics of fractures.The analysis reveals that the geometry and distribution of natural fractures,as well as reservoir geological parameters,significantly influence the fracture networkmorphology and fractal dimension.The contact angle between natural and hydraulic fractures affects propagation direction;specifically,when the contact angle isπ/2,the fractal dimension of the hydraulic fracture network is maximized.Moreover,smaller lengths and spacings of natural fracture led to higher fractal dimensions,which can significantly increase the SRV.The proposed method offers an effective tool for evaluating the hydraulic fracturing of coal reservoirs.
文摘According to World Health Organization,one in six people will be older than 60 by 2030.The rising life expectancy is anticipated to contribute to a subsequent increase of geriatric fractures worldwide.Osteosarcopenia,which is the coexistence of osteoporosis and sarcopenia,greatly affects older people.Recent studies have tried to identify the prevalence of osteosarcopenia in older populations as well as its correlation with fragility fractures such as hip fractures.The latter pose a major burden on both health loss and costs worldwide.Increasing amount of evidence suggests that osteosarcopenia in patients with hip fractures contributes to higher rates of mortality and complications.At the same time,research focuses on the molecular basis of the interplay between osteoporosis and sarcopenia by utilizing genomic or proteomic approaches.These promising studies could reveal potential preventive or diagnostic biomarkers to optimize the management of osteosarcopenia in hip fractures patients.The fact that bones and muscle can also function as endocrine organs further highlights the complex relationship between osteoporosis and sarcopenia,underscoring the need for a better understanding of the role of myokines and osteokines in osteosarcopenia.Finally,the impact of osteosarcopenia on pain management and rehabilitation after hip fracture surgery,requires further assessment.
文摘Prophylactic fixation(ProFix)of the proximal femur in elderly patients with osteoporosis presents a forward-thinking approach to preventing debilitating fractures and their associated complications.By addressing fracture risk before an injury occurs,ProFix has the potential to enhance patient outcomes,promote long-term mobility,and reduce healthcare costs.Early intervention in individuals at high risk can significantly lower hospital admissions,shorten recovery periods,and preserve independence,mitigating challenges such as chronic pain and reduced life expectancy.Given the high prevalence of undiagnosed osteoporosis,prioritising early risk assessment and targeted prevention is essential.Advancements in minimally invasive surgical techniques and safer anaesthesia methods further support ProFix as a feasible and effective strategy to decrease fracturerelated morbidity,improve overall patient well-being,and optimise the use of healthcare resources.This opinion review details the evidence supporting this concept,its efficacy,the challenges in its implementation,and a strategic plan for future implementation.
文摘BACKGROUND Radial head fractures constitute approximately one-third of all elbow fractures,significantly impacting the young and active population.While open reduction and internal fixation is the preferred treatment for displaced fractures,its high complication rate in comminuted fractures has led to the increasing use of radial head arthroplasty(RHA).RHA provides improved functional outcomes with fewer complications,yet its long-term efficacy remains a topic of debate.AIM To evaluate the functional outcomes of patients undergoing RHA with a modular metallic prosthesis for comminuted Mason type III and IV radial head fractures.METHODS A prospective and retrospective hospital-based study was conducted at Dayanand Medical College and Hospital,Ludhiana over 32 months(January 2021-August 2023).A total of 26 patients with Mason type III and IV fractures were included,with six retrospective and 20 prospective cases.Functional outcomes were assessed using the Mayo Elbow Performance Score(MEPS),elbow range of motion,pain via Visual Analog Scale,and activities of daily living at immediate postoperative,three-month,and six-month follow-ups.RESULTS MEPS at 6 months follow up for 4 cases(15.38%)had good scores,and 22 cases(84.62%)had excellent scores,with a mean±SD of 97.31±6.67.Comparisons showed significant improvement from immediate post-operative to 3 months(P<0.0001),from immediate post-operative to 6 months(P<0.0001),and between 3 months and 6 months(P<0.0001).None of the patients had elbow instability after radial head replacement and 22 cases(84.62%)had no complications,while 3 cases(11.54%)had a stiff elbow,and 1 case(3.85%)had heterotopic ossification.CONCLUSION RHA is an effective treatment for comminuted radial head fractures,providing stable elbow function with minimal complications.
基金supported by the National Natural Science Foundation of China(Nos.41807264,41972289)the Engineering Research Center of Rock-Soil Drilling&Excavation and Protection,Ministry of Education(No.202102)+3 种基金the Key Laboratory of Geological Hazards on Three Gorges Reservoir Area(China Three Gorges University),Ministry of Education(No.2020KDZ01)the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(Nos.CUG170686,CUGQY1932)the China Scholarship Council(No.201406410032)the Science and Technology Research Project of Education Department of Hubei Province(Nos.B2019452,B2024509)。
文摘A DFN-DEC(discrete fracture network-distinct element code)method based on the MATLAB platform is developed to generate heterogeneous DFN.Subsequently,the effects of the spatial variability(the meanμand the standard deviationσ)of the geometric properties(i.e.,the fracture dip D,the trace length T and the spacing S)of both the gently-dipping(denoted with 1)and the steeply-dipping(denoted with 2)fractures on the stability of granite slope are investigated.Results indicate that the proposed DFN-DEC method is robust,generating fracture networks that resemble reality.In addition,the spatial variability of fracture geometry,influencing the structure of granite slope,plays a significant role in slope stability.The mean stability of the slope decreases with the increase ofμ_(D_(1))(the mean of gently-dipping fracture dip),σ_(D_(2))(the mean of steeply-dipping fracture dip),μ_(T_(1))(the mean of gently-dipping fracture trace length),μ_(T_(2))(the mean of steeply-dipping fracture trace length),σ_(T_(1))(the standard deviation of gently-dipping fracture trace length),σ_(T_(2))(the standard deviation of steeply-dipping fracture trace length),and the decrease ofσ_(D_(1))(the standard deviation of gently-dipping fracture dip),μ_(D_(2))(the standard deviation of steeply-dipping fracture dip),μ_(S_(1))(the mean of gently-dipping fracture spacing)andμ_(S_(2))(the mean of steeply-dipping fracture spacing).Among them,μ_(T_(1)),μ_(D_(1))andμ_(S_(1))have the major impact.When the fracture spacing is large,the variability in the fracture geometry becomes less relevant to slope stability.When within some ranges of the fracture spacing,the spatial varying of dips can increase the slope stability by forming an interlaced structure.The results also show that the effects of the variability of trace length on slope stability depend on the variability of dip.These findings highlight the importance of spatial variability in the geometry of fractures to rock slope stability analysis.
文摘BACKGROUND Supracondylar humeral fractures(SCHF)are the second most common fractures in childhood and can lead to short-and long-term complications.Despite their prevalence,the anatomical factors that predispose children to SCHF remain unclear.This study aimed to determine whether there are significant morpho-logical differences in the elbow by comparing the radiographic angular measure-ments of the contralateral elbows of patients with SCHF to those of patients with distal radius fractures(DRF)and a healthy control group.We sought to explore if these morphological variations contribute to the occurrence of SCHF.Radiographs of 78 SCHF patients were analyzed for angular measurements of the contralateral elbow.Two control groups were used:98 healthy children and 40 patients with DRF.Angular measurements included Baumann angle(BA),hu-meroulnar angle(HUA),humerus metaphysis-diaphysis angle(HMDA),humerus shaft-condylar angle(HSCA),and lateral capitellohumeral angle.Only BA,HUA,and HMDA were measured in the DRF group.Statistical analysis was performed to compare differences among groups.RESULTS Significant differences were found in elbow measurements between SCHF and control groups(P<0.05).However,the mean values for all groups fell within the ranges described in the literature.CONCLUSION While statistically significant differences were found in elbow morphology between SCHF patients and controls,these differences don't translate into clinically meaningful morphological deviations.
文摘To accurately analyze proppant transport in rough intersecting fractures and elucidate the interaction mechanisms among liquid,particles,and rough walls,this study reconstructed a numerical model of fractures in inhomogeneous reservoirs with varying brittleness index(BI).Various auto-correlation Gaussian rough fracture models were created using Matlab to assess roughness through the fractal dimension method.This research innovatively combined Boolean operations to establish three-dimensional rough fracture models,incorporating(Computational Fluid Dynamics)CFD-DEM(Discrete Element Method)with a bidirectional method for cosimulation.The proppant transport in fractures was categorized into three zones based on the difference in the turbulent kinetic energy.Artificially induced fracture roughness increases fluid retention and turbulence,causing plugging effects and limiting proppant flow into branch fractures.Additionally,compared with the superior deposition and significant support effects of the spherical proppant,the low-sphericity proppant traveled farther under fracturing fluid,inducing more pronounced plugging near curved fracture intersections;the variation in fracture intersection angles primarily impacted the wall shear stress within the flow field,indicating smaller angles led to higher shear energy at the intersection.Compared with the intersection angle of 30°,the height and area deposited in the 90 branch fracture increased by 52.25%and 65.33%,respectively:notably,injecting proppant from smaller to larger particles(S:M:L)and a low velocity effectively ensured fracture conductivity near the wellbore at joint roughness coefficient(JRC)≥46 while achieving satis-factory placement in the branch fracture,making it a recommended approach.
基金the National Natural Science Foundation of China(No.52204052)the NationalNatural Science Foundation of China(No.U23B20156)the Sichuan Science and Technology Program(No.2023NSFSC0933).
文摘Shale reservoirs are characterized by numerous geological discontinuities,such as bedding planes,and exhibit pronounced heterogeneity across rock layers separated by these planes.Bedding planes often possess distinct mechanical properties compared to the surrounding rock matrix,particularly in terms of damage and fracture behavior.Consequently,vertical propagation of hydraulic fractures is influenced by both bedding planes and the heterogeneity.In this study,a numerical investigation into the height growth of hydraulic fractures was conducted using the finite element method,incorporating zero-thickness cohesive elements.The analysis explored the effects of bedding planes,toughness contrasts between layers,and variations in in-situ stress across different strata.The results reveal that hydraulic fractures are more likely to propagate along bedding planes instead of traversing them and extending vertically into barrier layers when(1)bedding strength is low,(2)stress contrast between layers is high,and(3)toughness contrast is significant.Furthermore,for a given bedding strength,increased stress contrast or higher toughness contrast between layers elevate hydraulic fracture extension pressure.When a substantial stress difference exists between layers(Lc 0.4),hydraulic=fractures preferentially propagate along bedding planes.Conversely,as bedding strength increases,the propagation distance along bedding planes decreases,accompanied by an amplified horizontal compressive stress field.Notably,when the stress difference is sufficiently small(SD a phenomenon termed“stress rolling”emerges,wherein<-0.2),hydraulic fractures deviate from vertical growth and instead extend along a near-horizontal trajectory.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51991392 and 42293355).
文摘Despite extensive research on computational geomechanics and fluid dynamics,accurately simulating convection-diffusion(CD)processes in complex fractured systems remains a significant challenge.This study develops a 3D numerical framework for modelling CD processes in fractured geological media.The framework integrates Darcy's law and Fick's law,considering flux interactions between the matrix and fractures.The meshing strategy generates high-quality grids even in scenarios involving intersecting fractures.Then,a unified numerical scheme for solving the CD system is proposed.The novelties of this work include:(1)The proposed framework enables effective simulation of 3D fractured media,including more complex fractured vuggy media;(2)The numerical method precisely discretizes the CD terms in governing equations;(3)A Non-Orthogonal Correction(NOC)method,combined with an adaptive time integration scheme,is proposed for eliminating errors induced by skewed grids;and(4)The effects of fracture patterns and heterogeneity on flow are thoroughly analysed.The proposed method is validated through benchmark tests,demonstrating the superiority of the NOC method compared to classical methods.Further analysis reveals the evolution characteristics of pressure and concentration,offering insights into the effects of fracture patterns and heterogeneity on flow and diffusion processes.
文摘BACKGROUND Periprosthetic fractures of the tibia are uncommon complications after total knee arthroplasty(TKA).Therefore,there is still clinical debate regarding the appropriate treatment method.This study presents the case of a patient with two successive periprosthetic fractures of the tibial shaft treated with revision TKA(rTKA)and intramedullary fixation.CASE SUMMARY A 65-year-old woman was treated for tibial shaft pseudarthrosis after a periprosthetic fracture.The patient underwent rTKA with a tibial component exchange to a long-stemmed implant.At her 1.5-year follow-up visit,partial asymptomatic bone union was noted with no prosthesis loosening.The patient achieved 0°to 120°range of motion and a stable knee,and reported high satisfaction.Improvements were observed in the Western Ontario and McMaster Universities Osteoarthritis Index(WOMAC)from 74 to 17,and in the knee society scores(KSS)from 56 to 91(clinical)and 10 to 80(functional).After 2.5 years,the patient sustained a second fracture below the original site due to low-energy trauma.The rTKA with intramedullary stabilization was performed.One year later,WOMAC and clinical and functional KSS were 15,81,and 80,respectively.Despite tibial shortening and lower limb inequality,the patient remains very satisfied and does not experience any issues with daily activities nor weight-bearing.CONCLUSION There is little consensus in the literature on the management of tibial shaft periprosthetic fractures.Intramedullary stabilization may yield excellent outcomes,but individual case discussion is necessary for rTKA indications.
基金supported by the National Natural Science Foundation of China(Grant No.12302500)the National Key Research and Development Program of China(Grant No.2020YFA0710503)Postdoctoral Fellowship Program(Grade B)of China Postdoctoral Science Foundation(Grant No.GBZ20230022).
文摘Controllable shock wave fracturing is an innovative engineering technique used for shale reservoir fracturing and reformation.Understanding the anisotropic fracture mechanism of shale under impact loading is vital for optimizing shock wave fracturing equipment and enhancing shale oil production.In this study,using the well-known notched semi-circular bend(NSCB)sample and the novel double-edge notched flattened Brazilian disc(DNFBD)sample combined with a split Hopkinson pressure bar(SHPB),various dynamic anisotropic fracture properties of Lushan shale,including failure characteristics,fracture toughness,energy dissipation and crack propagation velocity,are comprehensively compared and discussed under mode Ⅰ and mode Ⅱ fracture scenarios.First,using a newly modified fracture criterion considering the strength anisotropy of shale,the DNFBD specimen is predicted to be a robust method for true mode Ⅱ fracture of anisotropic shale rocks.Our experimental results show that the dynamic mode Ⅱ fracture of shale induces a rougher and more complex fracture morphology and performs a higher fracture toughness or fracture energy compared to dynamic mode Ⅰ fracture.The minimal fracture toughness or fracture energy occurs in the Short-transverse orientation,while the maximal ones occur in the Divider orientation.In addition,it is interesting to find that the mode Ⅱ fracture toughness anisotropy index decreases more slowly than that in the mode Ⅰ fracture scenario.These results provide significant insights for understanding the different dynamic fracture mechanisms of anisotropic shale rocks under impact loading and have some beneficial implications for the controllable shock wave fracturing technique.
基金supported by the China Scholarship Council(CSC)(Grant No.202006060033).
文摘Both the complex geometrical morphology of rough-walled rock fractures and the nonlinearity of fluid flow contribute to resistance in fluid flow through rock fractures.The interactions of the shear-flow process further complicate the characterisation of flow behaviours in rock fractures.In this study,an improved friction factor model involving both the effects of viscous and inertial forces is presented based on the Forchheimer equation.The model incorporates two key variables,i.e.Reynolds number and relative roughness,which reflect the effects of flow regimes and fracture roughness,respectively.The changes in geometrical parameters induced by shearing are considered,with the peak asperity height predicted through a correlation with post-peak roughness degradation.The hydraulic aperture during shearing is estimated using a suggested equation that accounts for the mobilised contact area ratio and variable aperture distribution.The parametric sensitivity analysis reveals that shear-induced changes in fracture geometry enhance the flow nonlinearity in rock fractures.The model performs well in predicting the friction factor based on two validation criteria.Then,the proposed friction factor model is incorporated into the three-dimensional distinct element code(3DEC)in the form of the Darcy-Weisbach equation.Coupled with the numerically implemented mechanical model and hydraulic aperture prediction model,numerical simulations of coupled shear-flow processes in single rock fractures are conducted.The simulation outcomes are validated through comparison with the experimental results,showing acceptable agreement and demonstrating that the numerical model is capable of accurately evaluating the hydro-mechanical coupling behaviour during the shearing of rock fractures.
基金supported by the Natural Science Foundation of China-Youth Foundation(42402163)Natural Science Foundation of Sichuan Province of China(2024NSFSC0814)Science and Technology Cooperation Project of the CNPC-SWPU Innovation Alliance(2020CX010101).
文摘The strike-slip fault system in the central Tarim Craton controls a complex petroleum system with estimated reserves exceeding 1×10^(9)t,the fault-related fractures are important for hydrocarbon accumulation.In this paper,the basic parameters such as density and width of fractures are counted and classified,and the effects of fractures on reservoirs are analyzed.The results show that:(1)Structural fractures and stylolite were widely developed in Halahatang area and experienced at least three stages of activity based on the infilling materials and crosscutting relationship.(2)Fracture density,width,aperture,and dip angle vary in different wells,but the relationship between the above parameters and the distance to the fault core indicates the fracture differences in the fault damage zone and further provides a method to divide the inner units in the fault damage zone.In addition,oil and gas wells with high production mainly concentrate in the inner unit.(3)The infilling materials and degree of fractures vary.Fractures formed in the early stage are more filled and less open,while the fractures formed in the late stage are relatively less filled and more open.(4)Fractures improve porosity to a certain extent but greatly increase permeability,especially in the inner zone of fault damage zone with large quantity,multiple inclinations,less filling and large width.These features contribute to the formation of a higher-quality reservoir,further improving oil and gas production.This paper provides a quantitative characterization method for the study of strike-slip fault-related fracture-caved reservoirs,and points out that fault damage zone,especially the inner zone of the fault damage zone,is the potential goal for oil and gas exploration.
基金supported in part by the National Key Research and Development Project of China(No.2022YFC3004602)in part by the National Natural Science Foundation of China(Nos.52121003 and 52342403).
文摘Multistage fracturing technology has been used to enhance tight hydrocarbon resource recovery.Determining the proper well spacing and fracturing strategy is crucial for generating a complex fracture network that facilitates oil and gas flow in reservoirs.The stress-shadow effect that occurs between multiple wells significantly affects the development of fracture networks in reservoirs.However,the quantification of the stress-shadow effect and its influence on fracture networks has not been satisfactorily resolved because of the difficulties in detecting and identifying fracture propagation and reorientation in reservoirs.In this study,based on the geological information from the Shengli oilfield,we applied a hybrid finite element-discrete element method to analyze engineering-scale three-dimensional fracture propagation and reorientation by altering well spacings and fracturing strategies.The results indicate that the fracturing area generated by the synchronous fracturing scheme is much smaller than those generated by the sequential and alternative schemes.An alternative hydrofracturing scheme is optimal with respect to fracturing area.The stress-blind area was defined to quantify the mechanical disturbance between adjacent wells.Our study improves the understanding of the effect of fracturing schemes on fracture networks and the impact of independent factors contributing to stress-shadow effects.
