scholarly journals Finite Element Analysis and Comparative Study of 4 Kinds of Internal Fixation Systems for Anterior Cervical Discectomy and Fusion in Children

2021 ◽  
Author(s):  
ziyu li ◽  
Jianqiang Zhou ◽  
Zhijun Li ◽  
Shaojie Zhang ◽  
xing wang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cervical Spine ◽  
Finite Element Model ◽  
Internal Fixation ◽  
Element Model ◽  
Lower Cervical Spine ◽  
Element Analysis ◽  
Internal Fixation System ◽  
Fixation System

Abstract Background: Spinal injury in children usually occurs in the cervical spine region. Anterior fixation of lower cervical spine has been applied in the treatment of pediatric cervical spine injury and disease due to its stable and firm mechanical properties. This study performed finite element analysis and comparison of 4 different anterior cervical internal fixation systems for children, and explored more stable methods of anterior cervical internal fixation in children. Methods: A finite element model of 6-year-old children with lower cervical spine C4/5 discectomy was established, and the self-designed lower cervical spine anterior locking internal fixation system ACBLP and the children’s anterior cervical internal fixation system ACOP, ACVLP, ACSLP plate screws were fixed and loaded on the model. 27.42N•m torque load was applied to each internal fixation model under 6 working conditions of anteflexion, backward flexion, left flexion, right flexion, left rotation and right rotation, to simulate the movement of the cervical spine. The activity and stress distribution cloud diagram of each finite element model was obtained. Results: In the four internal fixation models of ACOP, ACVLP, ACSLP, and ACBLP, the mobility of C4/5 segment basically showed a decreasing relationship, and the mobility of adjacent segments increased significantly. In the Mises stress cloud diagram of the cervical spine of the four models, the vertebral body and accessories of the ACBLP model born the least stress, followed by ACSLP; The steel plate and screws in the ACVLP internal fixation model were the most stressed; The stress of the internal fixation system (plate/screw) in all models increased in the order of ACBLP, ACSLP, ACVLP, and ACOP.Conclusions: ACBLP internal fixation system had obvious advantages in anterior internal fixation of lower cervical spine in children, C4/5 had the smallest degree of movement, relative displacement was minimal, the stress on the pedicle was the least while the stress on the plate screw was relatively the smallest.

scholarly journals A Finite Element Analysis of the Effects of Different Internal Fixation Strategies and Cage Implantation Methods on the Biomechanics of the Lumbar Spine

2021 ◽  
Author(s):  
zhenchuan Han ◽  
Bowen Ren ◽  
Keya Mao ◽  
Peifu Tang ◽  
Long Zhang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Lumbar Spine ◽  
Internal Fixation ◽  
Working Conditions ◽  
Peak Stress ◽  
Element Analysis ◽  
Model C ◽  
Internal Fixation System ◽  
Fixation System

Abstract Objective: Providing the biomechanical evidences to the surgeons on the internal fixation strategy and Cage implantation method in minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) by the finite element analysis (FEA).Methods: Firstly, based on the common MIS-TLIF surgical methods, three surgical models with different internal fixation strategies and Cage implantation methods were established. The surgical models simulated the physiological activities of the lumbar spine to evaluate the range of motion (ROM) of lumbar spine, the peak stress and the overall stress of the internal fixation system and Cage.Results: The results of the study show that the ROM of the surgical model has decreased significantly under all working conditions, and the decrease range is between 71.07-97.53%. The peak stress of the internal fixation system range was 48.56 to 100.09 MPa in Model-A, 58.10 to 136.05 MPa in Model-B, and 83.26 to 189.81 MPa in Model-C. Especially in the three working conditions of left lateral bending (LLB), left rotation (LR), and right rotation (RR), the peak stress of the internal fixation system of Model-C is 1.80 , 2.07, 1.79 times of Model-A and 2.05 , 1.64, 2.28 times of Model-B. The peak stress of Model-C Cage is significantly lower than Model-A and Model-B under all working conditions.Conclusion: Although the strategy of unilateral pedicle screw + lamina articular process screw + Cage horizontal implantation has the least Cage stress, there is a higher risk of internal fixation fail. Comprehensive evaluation, the surgical strategy of bilateral pedicle screw + Cage horizontal implantation has the best performance, and has the potential to become the standard implantation strategy of MIS-TLIF.

scholarly journals Finite element analysis of the optimal configuration of bridging combined internal fixation system in the treatment of vancouver B1 periprosthetic femoral fractures.

2021 ◽  
Author(s):  
Long Zhang ◽  
Md Ariful Haque ◽  
Ying Xiong ◽  
Jing Qin ◽  
Luyun Liu ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Fixation ◽  
Periprosthetic Fracture ◽  
Femoral Fractures ◽  
Optimal Configuration ◽  
Element Analysis ◽  
The Third ◽  
Internal Fixation System ◽  
Fixation System

Abstract Background and Objective: The incidence of periprosthetic fracture increases with the increase of total hip arthroplasty. The treatment of periprosthetic fracture is always a difficult point. The bridged combined internal fixation system (Ortho-bridge System, OBS) is well adapted to the characteristics of periprosthetic fractures.In this study, finite element analysis was used to evaluate the optimal configuration of OBS for fixation of Vancouver B1 periprosthetic femoral fractures.Methods: A three-rod combination OBS fixation model was established to evaluate the optimal position of the third rod, the cross Angle of proximal screws, the diameter of the connecting rod, and the number of screws. Femoral displacement and the maximum Von Mises (equivalent) stress of OBS were used as evaluation indexes.Results: The third rod is located at 35mm below the lateral fovea of the femur and the minimum Von Mises peak stress of OBS, which is the best location for placing the third rod. It is feasible for proximal screw intersection Angle to be about 71° and 84°.To fix the strength, the 6mm connecting rod is better. Considering the number of screws scheme comprehensively, scheme D is the best number of screws scheme.Conclusion: The personalized and diversified fixation mode of OBS is well adapted to the characteristics of periprosthetic fracture and provides an effective means for the treatment of periprosthetic femoral fracture.Statement : I confirm that this manuscript has not been published or presented elsewhere in part or entirety and is not under consideration by another journal. However, you may notice that a preprint has been published in research square https://www.researchsquare.com/article/rs-661745/v1, “Finite element analysis of the optimal configuration of bridging combined internal fixation system in the treatment of Vancouver B1 periprosthetic femoral fractures”. But it's not published or under consideration by any journal.

scholarly journals Analysis for Wrinkling Behavior of Girth-Welded Line Pipe

1996 ◽  
Author(s):  
Luiz T. Souza ◽  
David W. Murray
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Internal Pressure ◽  
Experimental Test ◽  
Element Model ◽  
Element Analysis ◽  
Line Pipe ◽  
New Era ◽  
Analytical Tools

The paper presents results for finite element analysis of full-sized girth-welded specimens of line pipe and compares these results with the behavior exhibited by test specimens subjected to constant axial force, internal pressure and monotonically increasing curvatures. Recommendations for the ‘best’ type of analytical finite element model are given. Comparisons between the behavior predicted analytically and the observed behavior of the experimental test specimens are made. The mechanism of wrinkling is explained and the evolution of the deformed configurations for different wrinkling modes is examined. It is concluded that the analytical tools now available are sufficiently reliable to predict the behavior of pipe in a manner that was not previously possible and that this should create a new era for the design and assessment of pipelines if the technology is properly exploited by industry.

Finite Element Analysis of Tandem Rubber O-Ring Sealing Structure at the End of Shaft

2013 ◽  
Vol 774-776 ◽  
pp. 25-29
Author(s):  
Cong Fang Hu ◽  
Yuan Qiang Tan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Compression Rate ◽  
Element Analysis ◽  
Uniform Compression ◽  
Friction Factors ◽  
Sealing Performance ◽  
Sealing Failure

Based on the tandem sealing structure at the end of the shaft,a finite element model of rubber O-rings has been established and the sealing performance of rubber O-ring has been analyzed. There is an un-uniform compression among these O-rings which lead to the sealing failure. Under different friction factors, several groups of the rubber O-rings have been analyzed, finding that the friction factor is the reason of un-uniform compression. The effect of different average compression rate has been investigated, which has been integrated in the sealing criteria for the tandem O-rings, providing a reference for the optimization of tandem sealing structure at the end of the shaft. According to the sealing criteria for a single O-ring, the sealing criteria for the tandem O-rings is built.

scholarly journals Finite Element- and Design of Experiment-Derived Optimization of Screw Configurations and a Locking Plate for Internal Fixation System

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Wei Sheng ◽  
Aimin Ji ◽  
Runxin Fang ◽  
Gang He ◽  
Changsheng Chen
Keyword(s):  
Finite Element ◽  
Internal Fixation ◽  
Locking Plate ◽  
Orthogonal Design ◽  
Structural Parameters ◽  
Uniform Design ◽  
Fracture Site ◽  
Element Analysis ◽  
Internal Fixation System ◽  
Fixation System

Objectives. The optimization for the screw configurations and bone plate parameters was studied to improve the biomechanical performances such as reliable internal fixation and beneficial callus growth for the clinical treatment of femoral shaft fracture. Methods. The finite element analysis (FEA) of internal fixation system under different screw configurations based on the orthogonal design was performed and so was for the different structural parameters of the locking plate based on the combination of uniform and orthogonal design. Moreover, orthogonal experiment weight matrixes for four evaluation indexes with FEA were analyzed. Results. The analytical results showed the optimal scheme of screw configuration was that screws are omitted in the thread holes near the fracture site, and single cortical screws are used in the following holes to the distal end, while the double cortical screws are fixed in thread holes that are distal to the fracture; in the other words, the length of the screws showed an increasing trend from the fracture site to the distal end in the optimized configuration. The plate structure was optimized when thread holes gap reached 13 mm, with a width of 11 mm and 4.6 mm and 5 mm for thickness and diameter of the screw, respectively. The biomechanical performance of the internal fixation construct was further improved by about 10% based on the optimal strain range and lower stress in the internal fixation system. Conclusions. The proposed orthogonal design and uniform design can be used in a more efficient way for the optimization of internal fixation system, which can reduce the simulation runs to about 10% compared with comprehensive test, and the methodology can be also used for other types of fractures to achieve better internal fixation stability and optimal healing efficiency, which may provide a method for an orthopedist in choosing the screw configurations and parameters for internal fixation system in a more efficient way.

Finite Element Analysis of Structural Strength of Concrete Mixing Truck’s Frame

2014 ◽  
Vol 945-949 ◽  
pp. 1143-1149
Author(s):  
Hai Xia Sun ◽  
Hua Kai Wei ◽  
Xiao Fang Zhao ◽  
Jia Rui Qi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Structural Strength ◽  
Element Model ◽  
Basic Element ◽  
Operating Conditions ◽  
Frame Structure ◽  
Element Analysis ◽  
The Finite Element Model

The finite element model of the concrete mixing truck’s frame is builded by using shell as basic element, and the process of building the finite element model of the balance suspension is introduced in detail. Based on this, frame’s stress on five types of typical operating conditions are calculated by using the finite element analysis software, NASTRAN, and results can show the dangerous position and the maximum stress position on the frame. The analysis result on structural strength can provide the basis for further improving the frame structure.

Dynamic Characteristics and Finite Element Model Updating of Micromachined Torsion Structures

2013 ◽  
Vol 284-287 ◽  
pp. 1831-1835
Author(s):  
Wei Hsin Gau ◽  
Kun Nan Chen ◽  
Yunn Lin Hwang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Model Updating ◽  
Speckle Pattern ◽  
Element Model ◽  
Mode Shapes ◽  
Electronic Speckle Pattern Interferometry ◽  
Finite Element Model Updating ◽  
Element Analysis

In this paper, two experimental techniques, Electronic Speckle Pattern Interferometry and Stroboscopic Interferometry, and two different finite element analysis packages are used to measure or to analyze the frequencies and mode shapes of a micromachined, cross-shaped torsion structure. Four sets of modal data are compared and shown having a significant discrepancy in their frequency values, although their mode shapes are quite consistent. Inconsistency in the frequency results due to erroneous inputs of geometrical and material parameters to the finite element analysis can be salvaged by applying the finite element model updating procedure. Two updating cases show that the optimization sequences converge quickly and significant improvements in frequency prediction are achieved. With the inclusion of the thickness parameter, the second case yields a maximum of under 0.4% in frequency difference, and all parameters attain more reliable updated values.

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