检索结果-南通市图书馆

Ultrasound Computed Tomography of knee joint

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2020年第4期29卷 705-716页

作者： LI Ruijing CHEN Houjin PENG Yahui LI Jupeng LI Yanfeng School of Electronic and Information Engineering Beijing Jiaotong University

Ultrasound computed tomography(UCT)is considered to have great potential for the early diagnosis of knee joint *** prior knowledge and sound speeds of tissues, UCT can diagnose a variety of symptoms and the extent of tissue ***, no existing studies can reconstruct the sound speed distributions of knee joints in ***,in this study, sound speed distributions of knee joints are reconstructed to provide an imaging basis for the formulation of a treatment *** addition, Full waveform inversion(FWI) methods are utilized to estimate highresolution ***, for media with large variations in sound speeds, traditional FWI methods may lead to a cycle-skipping phenomenon and incorrect convergence ***, this study proposes a multi-centerfrequency source based FWI method to overcome the above limitations.A penalized least-squares optimization problem is constructed to obtain a numerical solution of the sound speed *** simulations are conducted to prove the effectiveness and robustness of the proposed ***, the reasons for selecting the center frequencies of sources are *** numerical knee joint phantoms are used to evaluate the *** results suggest that the biases of the reconstructed images are less than 1% under a 5% noise condition.

关键词： Sound speed knee joint Image reconstruction Ultrasound computed tomography Full waveform inversion

Diagnostic value of diffusion-weighted MRI for imaging synovitis in pediatric patients with inflammatory conditions of the knee joint

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Pediatrics 2020年第1期16卷 60-67页

作者： Mengxia Li Alexander Sauer Annette Holl-Wieden Thomas Pabst Henning Neubauer Department of Radiation Oncology University Hospital Würzburg97080 WürzburgGermany Department of Diagnostic and Interventional Radiology University Hospital Würzburg97080 WürzburgGermany Department of Pediatrics University Hospital Würzburg97080 WürzburgGermany Department of Diagnostic and Interventional Radiology University Hospital Ulm89081 UlmGermany SRH Clinic of Radiology Albert-Schweitzer-Str.298527 SuhlGermany

Background Diffusion-weighted imaging(DWI)of synovitis has been suggested as a possible non-invasive alternative to contrast-enhanced T1w imaging(ce-T1w).We aimed to study DWI for diagnosing synovitis in the knee joint of pediatric patients,to quantify inter-observer agreement on DWI and ce-T1w and to calculate quantitative measures of synovial diffusivity and *** Forty consecutive patients with known or suspected arthritis of the knee(25 girls,median age 12 years)underwent routine 1.5T MRI with ce-T1w and transverse DWI with b values 50 and 800 s/*** apparent diffusion coefficient(ADC)values and signal intensity of inflamed synovium,joint effusion and muscle were measured with regions of interest ***-contrast T1 w images(diagnostic standard)and diffusion-weighted images at b=800 s/mm2 with ADC map were separately rated by three independent and blinded readers with different levels of expertise for the presence and degree of synovitis along with the level of diagnostic *** Thirty-one(78%)patients showed at least some synovial contrast enhancement,17(43%)children were diagnosed with synovitis on *** by the 1st reader on ce-T1w and on DWI for synovitis showed very good agreement(kappa=0.90).Inter-observer agreement on DWI ranged from moderate to substantial with kappa values between 0.68 and 0.79(all Pknee,based on our preliminary *** holds potential for increasing patient safety and comfort.

关键词： Diffusion-weighted imaging knee joint Magnetic resonance imaging Pediatric Synovitis

THREE-DIMENSIONAL FINITE ELEMENT SIMULATION OF TOTAL knee joint IN GAIT CYCLE

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2009年第4期22卷 347-351页

作者： Yuan Guo Xushu Zhang Weiyi Chen The Institute of Applied Mechanics and Biomedical Engineering Taiyuan University of Technology Taiyuan 030024 China

Based on CT scanning pictures from a volunteer＇s knee joint, a three-dimensional finite element model of the healthy human knee joint is constructed including complete femur, tibia, fibular, patellar and the main cartilage and ligaments. This model was validated using experimental and numerical results obtained from other authors. The pressure distribution of contact surfaces of knee joint are calculated and analyzed under the load action of ‘heel strike＇, ‘single limb stance＇ and ‘toe-off＇. The results of the gait cycle are that the contact areas of medial cartilage are larger than that of lateral cartilage; the contact force and contact areas would grow larger with the load increasing; the pressure of lateral meniscus is steady, relative to the significant variation of peak pressure in medial meniscus; and the peak value of contact pressure on all components are usually found at about 4570 of the gait cycle.

关键词： knee joint finite element simulation contact pressure biomechanics

Anatomy of the anterolateral ligament of the knee joint

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2022年第21期10卷 7215-7223页

作者： Jun-Gu Park Seung-Beom Han Hye Chang Rhim Ok Hee Jeon Ki-Mo Jang Department of Orthopaedic Surgery Anam HospitalKorea University College of MedicineSeoul 02841South Korea rtment of Biomedical Sciences Korea University College of MedicineSeoul 02841South Korea

Despite remarkable improvements in clinical outcomes after anterior cruciate ligament reconstruction,the residual rotational instability of knee joints remains a major *** anterolateral ligament(ALL)has recently gained attention as a distinct ligamentous structure on the anterolateral aspect of the knee *** studies investigated the anatomy,function,and biomechanics of ALL to establish its potential role as a stabilizer for anterolateral rotational ***,controversies regarding its existence,prevalence,and femoral and tibial insertions need to be *** to a recent consensus,ALL exists as a distinct ligamentous structure on the anterolateral aspect of the knee joint,with some anatomic *** aim of this article was to review the updated anatomy of ALL and present the most accepted findings among the existing ***,ALL originates slightly proximal and posterior to the lateral epicondyle of the distal femur and has an anteroinferior course toward the tibial insertion between the tip of the fibular head and Gerdy’s tubercle below the lateral tibial plateau.

关键词： knee joint Anatomy Anterolateral ligament Anterior cruciate ligament Anterolateral rotational instability Anterolateral ligament reconstruction

The knee joint Design and Control of Above-knee Intelligent Bionic Leg Based on Magneto-rheological Damper

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2010年第3期7卷 277-282页

作者： Hua-Long Xie Ze-Zhong Liang Fei Li Li-Xin Guo School of Mechanical Engineering and Automation Northeastern University Shenyang 110004 PRC School of Information Science and Engineering Shenyang University of Technology Shenyang 110178 PRC

The above-knee intelligent bionic leg is very helpful to amputees in the area of rehabilitation medicine. This paper first introduces the functional demand of the above-knee prosthesis design. Then, the advantages of the four-bar link mechanism and the magneto-rheological （MR） damper are analyzed in detail. The fixed position of the MR damper is optimized and a virtual prototype of knee joint is given. In the end, the system model of kinematics, dynamics, and controller are given and a control experiment is performed. The control experiment indicates that the intelligent bionic leg with multi-axis knee is able to realize gait tracking of the amputee＇s healthy leg based on semi-active control of the MR damper.

关键词： knee joint above-knee intelligent bionic leg magneto-rheological damper.

Modeling and analysis of knee joint impact damage in triple jump manipulators based on finite element method

在线全文

学校读者我要写书评

暂无评论

International Journal of Modeling, Simulation, and Scientific Computing 2019年第5期10卷 43-57页

作者： Mingquan Long Physical Education Department Hunan Vocational College of Commerce Changsha 410205 HunanP.R.China

In order to study the three jump training and competition on knee joint impact damage degree,left knee joint of one healthy male athletes is used as the research object,a complete knee three-dimensional model was established based on the jumper’s knee CT scan and magnetic resonance imaging(MRI),including the femur,tibia,fibula,patella and knee major cartilage,*** multi-body dynamics analysis(MDA)and finite element analysis(FEA)method are used to calculate the three jump,jump starting,landing process of athletes knee joint impact,the state should change the status of stress,strain and *** results show that in the three jump process,the load on the lateral contact area of the knee joint is the largest,the displacement is the largest,and it increases with the impact of jump and *** exacerbated the degree of wear and tear of the tibia,it tends to induce knee injury in *** results show that the combination of finite element and MDA can better study the knee joint’s shock and vibration during the three-level jump training and competition,and these open up a new research method for the knee joint *** also provides a certain reference for the prevention and treatment of knee joint injury.

关键词： knee joint triple jump impact behavior multibody dynamics finite element analysis

Formation process of extension knee joint contracture following external immobilization in rats

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Orthopedics 2023年第9期14卷 669-681页

作者： Chen-Xu Zhou Feng Wang Yun Zhou Qiao-Zhou Fang Quan-Bing Zhang Department of Rehabilitation Medicine The Second Affiliated Hospital of Anhui Medical UniversityHefei 230601Anhui ProvinceChina The Second Clinical Medicine College Anhui Medical UniversityHefei 230000Anhui ProvinceChina

BACKGROUND Current research lacks a model of knee extension contracture in *** To elucidate the formation process of knee extension *** We developed a rat model using an aluminum external *** male Sprague-Dawley rats with mature bones were divided into the control group(n=6)and groups that had the left knee immobilized with an aluminum external fixator for 1,2,and 3 d,and 1,2,3,4,6,and 8 wk(n=6 in each group).The passive extension range of motion,histology,and expression of fibrosis-related proteins were compared between the control group and the immobilization *** Myogenic contracture progressed very quickly during the initial 2 wk of *** 2 wk,the contracture gradually changed from myogenic to *** arthrogenic contracture progressed slowly during the 1^(st) week,rapidly progressed until the 3^(rd) week,and then showed a steady progression until the 4^(rd) *** analyses confirmed that the anterior joint capsule of the extended fixed knee became increasingly thicker over ***,the level of transforming growth factor beta 1(TGF-β1)and phosphorylated mothers against decapentaplegic homolog 2(p-Smad2)in the anterior joint capsule also increased with the immobilization *** time,the cross-sectional area of muscle fibers gradually decreased,while the amount of intermuscular collagen and TGF-β1,p-Smad2,and p-Smad3 was ***,the amount of intermuscular collagen and TGF-β1,p-Smad2,and p-Smad3 was decreased during the late stage of immobilization(6-8 wk).The myogenic contracture was stabilized after 2 wk of immobilization,whereas the arthrogenic contracture was stabilized after 3 wk of immobilization and completely stable in 4 *** This rat model may be a useful tool to study the etiology of joint contracture and establish therapeutic approaches.

关键词： knee joint Immobilization Contracture External fixator Rats

Effects of sex and lower extremity alignment on orientation of the knee joint line in knee surgery

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Medical Journal 2012年第12期125卷 2126-2131页

作者： ZENG Yi-ming WANG You ZHU Zhen-an DAI Ke-rong Department of Orthopedic Surgery Shanghai Ninth People'sHospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai 200011China

Background Determination of the proper orientation of the knee articular surface is required both for correction of knee malalignment by osteotomy and for correct component alignment in knee arthroplasty. We sought to determine whether the patients＇ sex and lower extremity alignment （hip-knee-ankle angle） affects proper knee realignment in osteotomy or component alignment in total knee arthroplasty. Methods We examined 199 healthy adult knees with malalignment of 〈5°to determine the mechanical medial distal femoral angle, mechanical medial proximal tibial angle, surgical transepicondylar axis angle, and discrepancies between bone-cut orientations of osteotomy or total knee arthroplasty and the joint line of the distal femoral condyles, posterior femoral condyles and proximal tibial plateaus, using a three-dimensional computed tomography model. Results The mean mechanical medial distal femoral angle and mean mechanical medial proximal tibial angle were （94.4±1.9）° and （87.6±1.8）° respectively for women and （93.8±2.0）° and （87.1±1.4）° respectively for men. The surgical transepicondylar axis angle was （2.9±1.6）° for women and （3.2±1.7）° for men. Independent of sex, the hip-knee-ankle angle was closely related to the mechanical medial distal femoral angle and mechanical medial proximal tibial angle, but not to the surgical transepicondylar axis angle. A slightly more valgus alignment of the knee and a more valgus angulation of the distal femoral joint line were found in women, whereas a more varus angulation of the proximal tibial joint line was found in men. Sex had the greatest effect on knee joint line orientation when the lower extremity was valgus in alignment. Conclusions A more valgus femoral joint line can be expected in women and in persons with valgus lower extremity aliqnment; a more varus tibial joint line can be found in men and in persons with varus lower extremity alignment.

关键词： knee joint sex lower extremity orientation

Synovial Neuronal Changes in knee joint Osteoarthritis

在线全文

学校读者我要写书评

暂无评论

Open Journal of Rheumatology and Autoimmune Diseases 2016年第2期6卷 26-33页

作者： Haq Nawaz Masood Umer Shahryar Noordin Bo Christer Bertilson Jian Li Aisha Siddiqah Ahmed Mahmood Ahmed Department of Surgery Aga Khan University Karachi Pakistan Karolinska Institute Department of Neurobiology Care Sciences and Society Huddinge Sweden Karolinska Institute Department of Molecular Medicine and Surgery Karolinska University Hospital Stockholm Sweden Karolinska Institute Department of Clinical Neurosciences Stockholm Sweden

Purpose: The purpose is to study whether pain and inflammation in knee joint osteoarthritis (OA) are associated with local synovial neuronal changes. Methods: Synovial biopsies were harvested from the medial and lateral knee compartments from OA patients undergoing total joint replacement surgery. All patients had predominant pain at the medial joint compartment. Pain and knee joint function were evaluated by knee society score (KSS). Synovial inflammation was analyzed by histopathological analysis and expression of growth associated protein-43 (GAP-43), sensory (SP, CGRP) and autonomic (NPY, VIP, TH) neuropeptides was studied by single and double immunohistochemistry techniques. Results: We observed reduced KSS and increased inflammatory score in synovial membrane of medial knee compartment. A significant increase in GAP-43 [P = 0.001], SP [P = 0.05], CGRP [P = 0.05] and TH [P = 0.05] expression was observed and SP, CGRP and NPY were found to be co-existed predominantly with GAP-43 in synovial membrane collected from medial compared to the lateral knee compartment. Conclusions: Regenerating nerve fibers containing sensory and autonomic neuropeptides are associated with pain and inflammation in knee joint OA.

关键词： Osteoarthritis knee joint Pain Inflammation Neuropeptides