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Use of oral ketamine for analgesia during reduction/manipulation of fracture/dislocation in the Emergency Room: An initial experience in a low-resource setting
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作者 E. Ogboli-Nwasor K. E. Amaefule S. S. Audu 《Pain Studies and Treatment》 2014年第1期17-20,共4页
Background: The use of ketamine for relief of procedure-related pain is limited in our environment. Ketamine, a phencyclidine derivative commonly used for induction and maintenance of anaesthesia, is administered rout... Background: The use of ketamine for relief of procedure-related pain is limited in our environment. Ketamine, a phencyclidine derivative commonly used for induction and maintenance of anaesthesia, is administered routinely via the intravenous and intramuscular routes. One of the concerns while using ketamine for analgesia via these two routes is that the drug may produce anaesthesia, rather than analgesia alone. Aims and Objectives: We sought to find out if ketamine given via the oral route could be used to provide analgesia during minor orthopaedic procedures in the emergency room. We also wanted to find out if there were side-effects peculiar to the oral route. Methods: A prospective observational pilot study in consecutive patientswith fractures/dislocation in our Emergency Room was recruited into the study. All patients gave informed consent. Reduction of fractures was done 15 minutes following the administration of ketamine 5 mg/kg orally. The patients were observed during and after the procedure and the findings entered into a proforma. The data obtained were analyzed using simple statistical methods and the results presented in a table. The findings are discussed. Results: There were 9 males and 2 females with an age range of 4 yrs to 48 yrs. Pain levels were assessed using verbal rating scales. Seven patients (64%) had severe pain before administration of ketamine while 2 patients (18%) each had mild and moderate pain respectively. Four patients had Colle’s fracture only and 1 patient had a Colle’s fracture with a supracondylar femoral fracture. Two patients had tibial fractures, one patient had a complete knee dislocation, while 2 others had ulnar/radial fractures. One other patient had humeral and tibial fractures. For up to 15 minutes after the procedures all but one patient were pain-free. Five (5) patients (45.5%) were noticed to have drowsiness, 3 patients (27%) were sedated while 2 patients (18%) had no side-effects at all. Five (5) patients (45.5%) reported excellent analgesia while 6 patients (64%) said the intra and post procedure analgesia was very good. Conclusions: Oral ketamine may be useful in providing analgesia for minor procedures in the emergency room. Ketamine when sweetened with a soda drink appears to be palatable with a rapid onset of action and few side effects. Thus ketamine given orally may be a cheaper and more accessible option for effective pain-relief in the emergency room. There is a need to conduct more studies on a larger number of patients. 展开更多
关键词 ORAL KETAMINE ANALGESIA fracture/dislocation EMERGENCY Room
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TINAVI robot-assisted one-stage anteroposterior surgery in lateral position for severe thoracolumbar fracture dislocation:A case report 被引量:2
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作者 Sen Ye Yan-Zhen Chen +3 位作者 Ling-Jian Zhong Chang-Zhang Yu Han-Kun Zhang Yang Hong 《World Journal of Clinical Cases》 SCIE 2023年第22期5358-5364,共7页
BACKGROUND The combined anterior/posterior approach appears to be capable of reconstructing spinal stability,correcting thoracolumbar deformity,and promoting neural recovery in severe thoracolumbar fracture dislocatio... BACKGROUND The combined anterior/posterior approach appears to be capable of reconstructing spinal stability,correcting thoracolumbar deformity,and promoting neural recovery in severe thoracolumbar fracture dislocation.However,this type of operation requires changing the body position during the procedure,resulting in a lengthy operation time.As a universal surgical robot,TINAVI robot has achieved good surgical results in clinical surgery.But to our knowledge,no reports describing TINAVI robot-assisted single lateral position anteroposterior surgery for thoracolumbar fracture dislocation.CASE SUMMARY We describe a case of a 16-year-old female patient with severe thoracolumbar fracture and dislocation underwent surgery assisted by the TINAVI robot.A onestage combined anterior and posterior operation was performed on a severe thoracolumbar fracture dislocation using the TINAVI robot,and the operation was completed in right lateral position.CONCLUSION The TINAVI robot-assisted one-stage anterior and posterior surgery in right lateral position for severe thoracolumbar fracture and dislocation is both safe and effective. 展开更多
关键词 TINAVI Thoracolumbar fracture Spine surgery Case report
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Unusual capitate fracture with dorsal shearing pattern and concomitant carpometacarpal dislocation with a 6-year follow-up:A case report
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作者 Chien-Cheng Lai Hsu-Wei Fang +3 位作者 Chih-Hung Chang Jwo-Luen Pao Chun-Chien Chang Yeong-Jang Chen 《World Journal of Clinical Cases》 SCIE 2023年第9期2060-2066,共7页
BACKGROUND Isolated capitate fractures are rare carpal fractures.Following high-energy injuries,capitate fractures are usually associated with other carpal fractures or ligament injuries.The management of capitate fra... BACKGROUND Isolated capitate fractures are rare carpal fractures.Following high-energy injuries,capitate fractures are usually associated with other carpal fractures or ligament injuries.The management of capitate fractures depends on the fracture pattern.Here,we report an unusual capitate fracture with a dorsal shearing pattern and concomitant carpometacarpal dislocation,with a 6-year follow-up.To the best of our knowledge,this fracture pattern and surgical management have not been previously reported.CASE SUMMARY A 28-year-old man presented with left-hand volar tenderness and decreased grip strength that persisted for one month after a traffic accident.Radiography showed a distal capitate fracture with carpometacarpal joint incongruence.Computed tomography(CT)revealed a distal capitate fracture with carpometacarpal joint dislocation.The distal fragment was rotated by 90°in the sagittal plane,and an oblique shearing fracture pattern was noted.Open reduction and internal fixation(ORIF)with a locking plate were performed using the dorsal approach.The imaging studies performed 3 mo and 6 years following surgery revealed a healed fracture,and the Disabilities of the Arm,Shoulder,and Hand and visual analog scale scores were significantly improved.CONCLUSION CT can detect capitate fractures with dorsal shearing pattern and concomitant carpometacarpal dislocation.ORIF using a locking plate are possible. 展开更多
关键词 Isolated capitate fracture Carpometacarpal dislocation Dorsal intercarpal ligament Case report
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Radial Head Dislocation Associated with an Ipsilateral Open Type II Gustilo-Anderson Fracture of the Radial Shaft
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作者 Gilbert F. O. Ngongang Paul U. Tambekou Tchatchuang +4 位作者 Jean G. Tsiagadigui Loïc Fonkoue Gaspary Fodjeu Marie A. Ngo Yamben Daniel E. Handy 《Open Journal of Orthopedics》 2023年第4期168-172,共5页
Radial head dislocation associated with an ipsilateral radial shaft fracture is a rare lesion, even more so for open lesions. Few cases have been found in the literature. We report this case due to its exceptional nat... Radial head dislocation associated with an ipsilateral radial shaft fracture is a rare lesion, even more so for open lesions. Few cases have been found in the literature. We report this case due to its exceptional nature and discuss the mechanism of onset. A twenty-five-year-old patient presented with a dislocation of the radial head associated with a GUSTILO ANDERSON type II open fracture of the radial shaft following an occupational accident. He was managed twenty-four hours after the trauma. The mechanism was a direct blow. The dislocation was reduced by external manoeuvre following open reduction of the radial shaft. The fracture was stabilized by two Kirschner wires following reduction. The result at 12 months was satisfactory from a clinical and radiological standpoint. 展开更多
关键词 Radial Head dislocation Radial Shaft fracture Kirschner Wires
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Locked Posterior Shoulder Dislocation with Impression Fracture Treated All Arthroscopically with the Use of an Allograft Bone Block: A Case Report
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作者 Adrian Błasiak Mikołaj Podsiadło +1 位作者 Marek Śliwa Roman Brzóska 《Open Journal of Orthopedics》 2023年第1期31-40,共10页
Background: Locked posterior shoulder dislocations are uncommon and possess many difficulties in diagnosis. They are often overlooked during the initial examination and delayed diagnosis adversely affects healing proc... Background: Locked posterior shoulder dislocations are uncommon and possess many difficulties in diagnosis. They are often overlooked during the initial examination and delayed diagnosis adversely affects healing process. Apart from many open treatment options, there are reports of single attempts to treat such cases arthroscopically. Purpose: We present an original case of a posterior locked dislocation of the shoulder joint with a fracture of the lesser tuberosity followed by reverse Hill-Sachs fracture, treated in a novel fashion all-arthroscopically with the use of allogenic bone graft. Method: According to Constant Shoulder Score that tries to assess functional and subjective performance of the shoulder joint before the operation and after 12 months, we achieved a leap from 11 to 84. Results: The patient restored almost full range of motion and painless movement in activities of daily life as well as during sports. Conclusion: The use of an arthroscope reduces the invasiveness of the procedure, improves visualization of the joint and allows augmentation of the bone loss without performing an open approach. We believe that this is a promising method of treatment for selected cases of locked posterior shoulder dislocation. 展开更多
关键词 Locked Posterior Shoulder dislocation ARTHROSCOPY Bone Graft Case Report
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Delayed dislocation of the radial head associated with malunion of distal radial fracture: A case report
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作者 Ki Bum Kim Sung Il Wang 《World Journal of Clinical Cases》 SCIE 2023年第18期4334-4340,共7页
BACKGROUND Traumatic radial head dislocation(RHD)is a well-described injury in the pediatric population.It is usually associated with an injury to the ulna in Monteggia fracture-dislocation,although it can occur as an... BACKGROUND Traumatic radial head dislocation(RHD)is a well-described injury in the pediatric population.It is usually associated with an injury to the ulna in Monteggia fracture-dislocation,although it can occur as an isolated injury.Traumatic RHD with ipsilateral radial shaft fracture has rarely been reported.Delayed RHD secondary to the malunion of an isolated radial shaft fracture is extremely rare.CASE SUMMARY We report a 9-year-old boy with limited pronation of the right elbow.The patient was diagnosed with delayed RHD associated with the malunion of a distal radial fracture.Since the annular ligament was disrupted with forearm rotation causing subluxation of the radial head,a modified double-strip Bell Tawse procedure was performed to reconstruct the annular ligament without corrective osteotomy for the malunited site.Four years after surgery,the angulation deformity of the distal radius was corrected with the restoration of the normal curvature of the radius.There was no recurrence of RHD.CONCLUSION Annular ligament reconstruction without corrective osteotomy could reduce RHD and restore the normal curve of the radial shaft in children with delayed dislocation of the radial head associated with malunion of the radial shaft.Annular reconstruction using double triceps tendon strips might be useful for maintaining a more stable reduction by augmenting anterolateral parts. 展开更多
关键词 dislocation Radial head MALUNION Radius shaft Reconstruction Annular ligament Case report
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Challenges of Total Arthroplasty for Neglected Fracture-Dislocations of the Hip
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作者 Papa Amadou Ba Souleymane Diao Chérif Sadibou Djiba 《Open Journal of Orthopedics》 2023年第10期421-426,共6页
This study examined neglected hip fracture-dislocations in developing countries, focusing on five cases in Dakar. The research adopted a prospective method, assessing epidemiological, clinical, radiological, and thera... This study examined neglected hip fracture-dislocations in developing countries, focusing on five cases in Dakar. The research adopted a prospective method, assessing epidemiological, clinical, radiological, and therapeutic aspects, utilizing the Postel Merle d’Aubigné scoring system for functional assessment. Results demonstrated that total joint replacement surgery, predominantly following traffic accidents, significantly improved mobility and reduced limb length disparity, with most patients achieving independent walking post-operation. The study concludes that early diagnosis and total hip arthroplasty are critical for optimal outcomes. 展开更多
关键词 ARTHROPLASTY HIP Neglected fracture-Luxation
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FRACTURE序列在中轴型脊柱关节炎骶髂关节结构性病变中的诊断价值
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作者 章忆惠 程艺璇 +4 位作者 徐磊 徐凌霄 谈文峰 王梦悦 祁良 《放射学实践》 CSCD 北大核心 2024年第7期929-934,共6页
目的:评估限制回波间隔的快速梯度回波类CT成像(FRACTURE)序列在检测中轴型脊柱关节炎(SpA)骶髂关节结构病变中的诊断价值。方法:回顾性分析83例确诊中轴型SpA患者在2021年12月-2022年8月进行骶髂关节MRI和CT检查的影像资料。评估图像包... 目的:评估限制回波间隔的快速梯度回波类CT成像(FRACTURE)序列在检测中轴型脊柱关节炎(SpA)骶髂关节结构病变中的诊断价值。方法:回顾性分析83例确诊中轴型SpA患者在2021年12月-2022年8月进行骶髂关节MRI和CT检查的影像资料。评估图像包括FRACTURE、T_(1)WI序列和CT平扫图像。对骶髂关节的影像图像进行结构性病变评分:关节间隙变化(0~5分)、骨质侵蚀(0~3分)和骨质硬化(0~2分)。根据修改后的纽约标准评分系统对骶髂关节炎进行综合评分。结果:总共有166个骶髂关节图像(83名受试者)可供分析。以CT图像作为参考标准,FRACTURE序列在关节间隙改变、骨质侵蚀、骨质硬化和骶髂关节炎综合评分与CT结果表现出较高的一致性,AUC分别为0.908、0.943、0.918和0.944。与T_(1)WI相比,FRACTURE在关节间隙变化(91.8%vs.70.5%)、骨质侵蚀(93.3%vs.56.4%)、骨质硬化(94%vs.77.6%)和骶髂关节炎综合评分(98.9%vs.75.3%)方面具有更高的诊断准确性。结论:FRACTURE成像可以评估中轴型SpA患者骶髂关节的结构性病变,并显示出良好的诊断性能。 展开更多
关键词 fracture序列 骶髂关节 脊柱关节病 磁共振成像 体层摄影术 X线计算机
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Complication rates after direct anterior vs posterior approach for hip hemiarthroplasty in elderly individuals with femoral neck fractures 被引量:2
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作者 Tatiana Charles Nicolas Bloemers +1 位作者 Bilal Kapanci Marc Jayankura 《World Journal of Orthopedics》 2024年第1期22-29,共8页
BACKGROUND Dislocation rates after hemiarthroplasty reportedly vary from 1%to 17%.This serious complication is associated with increased morbidity and mortality rates.Approaches to this surgery are still debated,with ... BACKGROUND Dislocation rates after hemiarthroplasty reportedly vary from 1%to 17%.This serious complication is associated with increased morbidity and mortality rates.Approaches to this surgery are still debated,with no consensus regarding the superiority of any single approach.AIM To compare early postoperative complications after implementing the direct anterior and posterior approaches(PL)for hip hemiarthroplasty after femoral neck fractures.METHODS This is a comparative,retrospective,single-center cohort study conducted at a university hospital.Between March 2008 and December 2018,273 patients(a total of 280 hips)underwent bipolar hemiarthroplasties(n=280)for displaced femoral neck fractures using either the PL(n=171)or the minimally invasive direct anterior approach(DAA)(n=109).The choice of approach was related to the surgeons’practices;the implant types were similar and unrelated to the approach.Dislocation rates and other complications were reviewed after a minimum followup of 6 mo.RESULTS Both treatment groups had similarly aged patients(mean age:82 years),sex ratios,patient body mass indexes,and patient comorbidities.Surgical data(surgery delay time,operative time,and blood loss volume)did not differ significantly between the groups.The 30 d mortality rate was higher in the PL group(9.9%)than in the DAA group(3.7%),but the difference was not statistically significant(P=0.052).Among the one-month survivors,a significantly higher rate of dislocation was observed in the PL group(14/154;9.1%)than in the DAA group(0/105;0%)(P=0.002).Of the 14 patients with dislocation,8 underwent revision surgery for recurrent instability(posterior group),and one of them had 2 additional procedures due to a deep infection.The rate of other complications(e.g.,perioperative and early postoperative periprosthetic fractures and infection-related complications)did not differ significantly between the groups.CONCLUSION These findings suggest that the DAA to bipolar hemiarthroplasty for patients with femoral neck fractures is associated with a lower dislocation rate(<1%)than the PL. 展开更多
关键词 HEMIARTHROPLASTY Femoral neck fracture Direct anterior approach Posterior approach dislocation MORTALITY
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Study of hydro-mechanical behaviours of rough rock fracture with shear dilatancy and asperities using shear-flow model 被引量:1
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作者 Luyu Wang Weizhong Chen Qun Sui 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第10期4004-4016,共13页
The geometric properties of fracture surfaces significantly influence shear-seepage in rock fractures,introducing complexities to fracture modelling.The present study focuses on the hydro-mechanical behaviours of roug... The geometric properties of fracture surfaces significantly influence shear-seepage in rock fractures,introducing complexities to fracture modelling.The present study focuses on the hydro-mechanical behaviours of rough rock fractures during shear-seepage processes to reveal how dilatancy and fracture asperities affect these phenomena.To achieve this,an improved shear-flow model(SFM)is proposed with the incorporation of dilatancy effect and asperities.In particular,shear dilatancy is accounted for in both the elastic and plastic stages,in contrast to some existing models that only consider it in the elastic stage.Depending on the computation approaches for the peak dilatancy angle,three different versions of the SFM are derived based on Mohr-Coulomb,joint roughness coefficient-joint compressive strength(JRC-JCS),and Grasselli’s theories.Notably,this is a new attempt that utilizes Grasselli’s model in shearseepage analysis.An advanced parameter optimization method is introduced to accurately determine model parameters,addressing the issue of local optima inherent in some conventional methods.Then,model performance is evaluated against existing experimental results.The findings demonstrate that the SFM effectively reproduces the shear-seepage characteristics of rock fracture across a wide range of stress levels.Further sensitivity analysis reveals how dilatancy and asperity affect hydraulic properties.The relation between hydro-mechanical properties(dilatancy displacement and hydraulic conductivity)and asperity parameters is analysed.Several profound understandings of the shear-seepage process are obtained by exploring the phenomenon under various conditions. 展开更多
关键词 Rock fracture Stress-seepage coupling Shear-flow model fracture asperity Shear dilatancy
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Numerical modeling of fracture propagation of supercritical CO_(2)compound fracturing 被引量:1
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作者 Hao Chen Yong Kang +2 位作者 Wanchun Jin Changhai Li Can Cai 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第7期2607-2628,共22页
The exploitation of shale gas is promising due to depletion of the conventional energy and intensification of the greenhouse effect.In this paper,we proposed a heat-fluid-solid coupling damage model of supercritical C... The exploitation of shale gas is promising due to depletion of the conventional energy and intensification of the greenhouse effect.In this paper,we proposed a heat-fluid-solid coupling damage model of supercritical CO_(2)(SC-CO_(2))compound fracturing which is expected to be an efficient and environmentally friendly way to develop shale gas.The coupling model is solved by the finite element method,and the results are in good agreement with the analytical solutions and fracturing experiments.Based on this model,the fracture propagation characteristics at the two stages of compound fracturing are studied and the influence of pressurization rate,in situ stress,bedding angle,and other factors are considered.The results show that at the SC-CO_(2)fracturing stage,a lower pressurization rate is conducive to formation of the branches around main fractures,while a higher pressurization rate inhibits formation of the branches around main fractures and promotes formation of the main fractures.Both bedding and in situ stress play a dominant role in the fracture propagation.When the in situ stress ratio(δ_(x)/δ_(y))is 1,the presence of bedding can reduce the initiation pressure and failure pressure.Nevertheless,it will cause the fracture to propagate along the bedding direction,reducing the fracture complexity.In rocks without bedding,hydraulic fracturing has the lengthening and widening effects for SC-CO_(2)induced fracture.In shale,fractures induced at the hydraulic fracturing stage are more likely to be dominated by in situ stresses and have a shorter reorientation radius.Therefore,fracture branches propagating along the maximum principal stress direction may be generated around the main fractures induced by SC-CO_(2)at the hydraulic fracturing stage.When the branches converge with the main fractures,fracture zones are easily formed,and thus the fracture complexity and damage area can be significantly increased.The results are instructive for the design and application of SC-CO_(2)compound fracturing. 展开更多
关键词 Compound fracturing fracture propagation Finite element method Damage evolution
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Shared genetic architecture highlights the bidirectional association between major depressive disorder and fracture risk 被引量:1
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作者 Pianpian Zhao Zhimin Ying +10 位作者 Chengda Yuan Haisheng Zhang Ao Dong Jianguo Tao Xiangjiao Yi Mengyuan Yang Wen Jin Weiliang Tian David Karasik Geng Tian Houfeng Zheng 《General Psychiatry》 CSCD 2024年第3期352-363,共12页
Background There is limited evidence suggesting that osteoporosis might exacerbate depressive symptoms,while more studies demonstrate that depression negatively affects bone density and increases fracture risk.Aims To... Background There is limited evidence suggesting that osteoporosis might exacerbate depressive symptoms,while more studies demonstrate that depression negatively affects bone density and increases fracture risk.Aims To explore the relationship between major depressive disorder(MDD)and fracture risk.Methods We conducted a nested case-control analysis(32670 patients with fracture and 397017 individuals without fracture)and a matched cohort analysis(16496 patients with MDD and 435492 individuals without MDD)in the same prospective UK Biobank data set.Further,we investigated the shared genetic architecture between MDD and fracture with linkage disequilibrium score regression and the MiXeR statistical tools.We used the conditional/conjunctional false discovery rate approach to identify the specific shared loci.We calculated the weighted genetic risk score for individuals in the UK Biobank and logistic regression was used to confirm the association observed in the prospective study.Results We found that MDD was associated with a 14%increase in fracture risk(hazard ratio(HR)1.14,95%CI 1.14 to 1.15,p<0.001)in the nested case-control analysis,while fracture was associated with a 72%increase in MDD risk(HR 1.72,95%CI 1.64 to 1.79,p<0.001)in the matched cohort analysis,suggesting a longitudinal and bidirectional relationship.Further,genetic summary data suggested a genetic overlap between MDD and fracture.Specifically,we identified four shared genomic loci,with the top signal(rs7554101)near SGIP1.The protein encoded by SGIP1 is involved in cannabinoid receptor type 1 signalling.We found that genetically predicted MDD was associated with a higher risk of fracture and vice versa.In addition,we found that the higher expression level of SGIP1 in the spinal cord and muscle was associated with an increased risk of fracture and MDD.Conclusions The genetic pleiotropy between MDD and fracture highlights the bidirectional association observed in the epidemiological analysis.The shared genetic components(such as SGIP1)between the diseases suggest that modulating the endocannabinoid system could be a potential therapeutic strategy for both MDD and bone loss. 展开更多
关键词 fracture matched OSTEOPOROSIS
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Management and classification of the fracture of lateral process of talus:An overview and literature update 被引量:1
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作者 Chao-Qun Wang Ulrich Stockle +2 位作者 Sheng-Nan Dong Xu-Gui Li Ze-Xi Ling 《World Journal of Clinical Cases》 SCIE 2024年第15期2487-2498,共12页
Fracture of the lateral process of the talus(FLPT)is uncommon in clinical practice and can be easily missed or misdiagnosed.In recent years,as researchers from all over the world have further deepened their research o... Fracture of the lateral process of the talus(FLPT)is uncommon in clinical practice and can be easily missed or misdiagnosed.In recent years,as researchers from all over the world have further deepened their research on FLPT,there has been a breakthrough in the classification,and the methods and principles of clinical management have changed accordingly;however,there is still no standardized guideline for the diagnosis and management of FLPT,and there have been few relevant literature review articles related to this kind of fracture in the past at least 5 years.In this article,we review the clinical classification,classification-based therapeutic recommendations,and prognosis of FLPT,with the aim of providing a reference for the clinical diagnosis and management of this infrequent fracture. 展开更多
关键词 fracture of the lateral process of the talus fracture of the talus Hindfoot injuries Intraarticular fracture Subtalar joint
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Effect of fracture fluid flowback on shale microfractures using CT scanning 被引量:2
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作者 Jiale He Zhihong Zhao +6 位作者 Yiran Geng Yuping Chen Jianchun Guo Cong Lu Shouyi Wang Xueliang Han Jun Zhang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第2期426-436,共11页
The field data of shale fracturing demonstrate that the flowback performance of fracturing fluid is different from that of conventional reservoirs,where the flowback rate of shale fracturing fluid is lower than that o... The field data of shale fracturing demonstrate that the flowback performance of fracturing fluid is different from that of conventional reservoirs,where the flowback rate of shale fracturing fluid is lower than that of conventional reservoirs.At the early stage of flowback,there is no single-phase flow of the liquid phase in shale,but rather a gas-water two-phase flow,such that the single-phase flow model for tight oil and gas reservoirs is not applicable.In this study,pores and microfractures are extracted based on the experimental results of computed tomography(CT)scanning,and a spatial model of microfractures is established.Then,the influence of rough microfracture surfaces on the flow is corrected using the modified cubic law,which was modified by introducing the average deviation of the microfracture height as a roughness factor to consider the influence of microfracture surface roughness.The flow in the fracture network is simulated using the modified cubic law and the lattice Boltzmann method(LBM).The results obtained demonstrate that most of the fracturing fluid is retained in the shale microfractures,which explains the low fracturing fluid flowback rate in shale hydraulic fracturing. 展开更多
关键词 SHALE Flowback of fracturing fluid MICROfracture Lattice Boltzmann method(LBM)
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Creep constitutive model considering nonlinear creep degradation of fractured rock 被引量:1
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作者 Wang Chunping Liu Jianfeng +3 位作者 Chen Liang Liu Jian Wang Lu Liao Yilin 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第1期105-116,共12页
Stability analysis of underground constructions requires a model study of rock masses’ long-term performance. Creep tests under different stress conditions was conducted on intact granite and granite samples fracture... Stability analysis of underground constructions requires a model study of rock masses’ long-term performance. Creep tests under different stress conditions was conducted on intact granite and granite samples fractured at 30° and 45° angles. The experimental results indicate that the steady creep strain rates of intact and fractured rock present an exponential increase trend with the increase of stress level. A nonlinear creep model is developed based on the experimental results, in which the initial damage caused by fracture together with the damage caused by constant load have been taken into consideration. The fitting analysis results indicated that the model proposed is more accurate at identifying the full creep regions in fractured granite, especially the accelerated stage of creep deformation. The least-square fit error of the proposed creep model is significantly lower than that of Nishihara model by almost an order of magnitude. An analysis of the effects of elastic modulus, viscosity coefficient, and damage factors on fractured rock strain rate and creep strain is conducted. If no consideration is given to the effects of the damage, the proposed nonlinear creep model can degenerate into to the classical Nishihara model. 展开更多
关键词 fractured rock DAMAGE CREEP Beishan granite Geological disposal
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Evaluating the stability and volumetric flowback rate of proppant packs in hydraulic fractures using the lattice Boltzmann-discrete element coupling method 被引量:1
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作者 Duo Wang Sanbai Li +2 位作者 Rui Wang Binhui Li Zhejun Pan 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期2052-2063,共12页
The stability and mobility of proppant packs in hydraulic fractures during hydrocarbon production are numerically investigated by the lattice Boltzmann-discrete element coupling method(LB-DEM).This study starts with a... The stability and mobility of proppant packs in hydraulic fractures during hydrocarbon production are numerically investigated by the lattice Boltzmann-discrete element coupling method(LB-DEM).This study starts with a preliminary proppant settling test,from which a solid volume fraction of 0.575 is calibrated for the proppant pack in the fracture.In the established workflow to investigate proppant flowback,a displacement is applied to the fracture surfaces to compact the generated proppant pack as well as further mimicking proppant embedment under closure stress.When a pressure gradient is applied to drive the fluid-particle flow,a critical aperture-to-diameter ratio of 4 is observed,above which the proppant pack would collapse.The results also show that the volumetric proppant flowback rate increases quadratically with the fracture aperture,while a linear variation between the particle flux and the pressure gradient is exhibited for a fixed fracture aperture.The research outcome contributes towards an improved understanding of proppant flowback in hydraulic fractures,which also supports an optimised proppant size selection for hydraulic fracturing operations. 展开更多
关键词 Numerical simulation Hydraulic fracturing Proppant flowback Closure stress Particulate flow
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A method to interpret fracture aperture of rock slope using adaptive shape and unmanned aerial vehicle multi-angle nap-of-the-object photogrammetry 被引量:2
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作者 Mingyu Zhao Shengyuan Song +3 位作者 Fengyan Wang Chun Zhu Dianze Liu Sicong Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第3期924-941,共18页
The aperture of natural rock fractures significantly affects the deformation and strength properties of rock masses,as well as the hydrodynamic properties of fractured rock masses.The conventional measurement methods ... The aperture of natural rock fractures significantly affects the deformation and strength properties of rock masses,as well as the hydrodynamic properties of fractured rock masses.The conventional measurement methods are inadequate for collecting data on high-steep rock slopes in complex mountainous regions.This study establishes a high-resolution three-dimensional model of a rock slope using unmanned aerial vehicle(UAV)multi-angle nap-of-the-object photogrammetry to obtain edge feature points of fractures.Fracture opening morphology is characterized using coordinate projection and transformation.Fracture central axis is determined using vertical measuring lines,allowing for the interpretation of aperture of adaptive fracture shape.The feasibility and reliability of the new method are verified at a construction site of a railway in southeast Tibet,China.The study shows that the fracture aperture has a significant interval effect and size effect.The optimal sampling length for fractures is approximately 0.5e1 m,and the optimal aperture interpretation results can be achieved when the measuring line spacing is 1%of the sampling length.Tensile fractures in the study area generally have larger apertures than shear fractures,and their tendency to increase with slope height is also greater than that of shear fractures.The aperture of tensile fractures is generally positively correlated with their trace length,while the correlation between the aperture of shear fractures and their trace length appears to be weak.Fractures of different orientations exhibit certain differences in their distribution of aperture,but generally follow the forms of normal,log-normal,and gamma distributions.This study provides essential data support for rock and slope stability evaluation,which is of significant practical importance. 展开更多
关键词 Unmanned aerial vehicle(UAV) PHOTOGRAMMETRY High-steep rock slope fracture aperture Interval effect Size effect Parameter interpretation
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Experimental investigation on coal pore-fracture variation and fractal characteristics synergistically affected by solvents for improving clean gas extraction 被引量:1
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作者 Feilin Han Sheng Xue +3 位作者 Chunshan Zheng Zhongwei Chen Guofu Li Bingyou Jiang 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第3期413-425,共13页
Chemical solvents instead of pure water being as hydraulic fracturing fluid could effectively increase permeability and improve clean methane extraction efficiency.However,pore-fracture variation features of lean coal... Chemical solvents instead of pure water being as hydraulic fracturing fluid could effectively increase permeability and improve clean methane extraction efficiency.However,pore-fracture variation features of lean coal synergistically affected by solvents have not been fully understood.Ultrasonic testing,nuclear magnetic resonance analysis,liquid phase mass spectrometry was adopted to comprehensively analyze pore-fracture change characteristics of lean coal treated by combined solvent(NMP and CS_(2)).Meanwhile,quantitative characterization of above changing properties was conducted using geometric fractal theory.Relationship model between permeability,fractal dimension and porosity were established.Results indicate that the end face fractures of coal are well developed after CS2and combined solvent treatments,of which,end face box-counting fractal dimensions range from 1.1227 to 1.4767.Maximum decreases in ultrasonic longitudinal wave velocity of coal affected by NMP,CS_(2)and combined solvent are 2.700%,20.521%,22.454%,respectively.Solvent treatments could lead to increasing amount of both mesopores and macropores.Decrease ratio of fractal dimension Dsis 0.259%–2.159%,while permeability increases ratio of NMR ranges from 0.1904 to 6.4486.Meanwhile,combined solvent could dissolve coal polar and non-polar small molecules and expand flow space.Results could provide reference for solvent selection and parameter optimization of permeability-enhancement technology. 展开更多
关键词 Clean gas extraction Chemical solvent Experimental investigation Fractal characteristics Pore fracture
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Estimation of the anisotropy of hydraulic conductivity through 3D fracture networks using the directional geological entropy 被引量:1
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作者 Chuangbing Zhou Zuyang Ye +2 位作者 Chi Yao Xincheng Fan Feng Xiong 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第2期137-148,共12页
With an extension of the geological entropy concept in porous media,the approach called directional entrogram is applied to link hydraulic behavior to the anisotropy of the 3D fracture networks.A metric called directi... With an extension of the geological entropy concept in porous media,the approach called directional entrogram is applied to link hydraulic behavior to the anisotropy of the 3D fracture networks.A metric called directional entropic scale is used to measure the anisotropy of spatial order in different directions.Compared with the traditional connectivity indexes based on the statistics of fracture geometry,the directional entropic scale is capable to quantify the anisotropy of connectivity and hydraulic conductivity in heterogeneous 3D fracture networks.According to the numerical analysis of directional entrogram and fluid flow in a number of the 3D fracture networks,the hydraulic conductivities and entropic scales in different directions both increase with spatial order(i.e.,trace length decreasing and spacing increasing)and are independent of the dip angle.As a result,the nonlinear correlation between the hydraulic conductivities and entropic scales from different directions can be unified as quadratic polynomial function,which can shed light on the anisotropic effect of spatial order and global entropy on the heterogeneous hydraulic behaviors. 展开更多
关键词 3D fracture network Geological entropy Directional entropic scale ANISOTROPY Hydraulic conductivity
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A coupled thermo-mechanical peridynamic model for fracture behavior of granite subjected to heating and water-cooling processes 被引量:1
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作者 Luming Zhou Zhende Zhu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期2006-2018,共13页
Thermal damage and thermal fracture of rocks are two important indicators in geothermal mining projects.This paper investigates the effects of heating and water-cooling on granite specimens at various temperatures.The... Thermal damage and thermal fracture of rocks are two important indicators in geothermal mining projects.This paper investigates the effects of heating and water-cooling on granite specimens at various temperatures.The laboratory uniaxial compression experiments were also conducted.Then,a coupled thermo-mechanical ordinary state-based peridynamic(OSB-PD)model and corresponding numerical scheme were developed to simulate the damage of rocks after the heating and cooling processes,and the change of crack evolution process was predicted.The results demonstrate that elevated heating temperatures exacerbate the thermal damage to the specimens,resulting in a decrease in peak strength and an increase in ductility of granite.The escalating occurrence of thermal-induced cracks significantly affects the crack evolution process during the loading phase.The numerical results accurately reproduce the damage and fracture characteristics of the granite under different final heating temperatures(FHTs),which are consistent with the test results in terms of strength,crack evolution process,and failure mode. 展开更多
关键词 Peridynamics(PD) GRANITE Heating and cooling Damage and fracture Uniaxial compression
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