scholarly journals Oblique Lateral Interbody Fusion Combined With Different Internal Fixations in The Treatment of Degenerative Lumbar Spine Disease: A Finite Element Analysis

2021 ◽  
Author(s):  
ShuYi Zhang ◽  
Zhengpeng Liu ◽  
Chenshui Lu ◽  
Li Zhao ◽  
Chao Feng ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Finite Element ◽  
Internal Fixation ◽  
Pedicle Screw ◽  
Interbody Fusion ◽  
Three Dimensional ◽  
Fe Analysis ◽  
The Other ◽  
The Stability ◽  
Unilateral Pedicle Screw

Abstract Little is known about the biomechanical performance of various internal fixations in oblique lumbar interbody fusion (OLIF). In this study, finite element (FE) analysis was used to describe the biomechanical findings of various different internal fixations to compare and explore the stability of each fixation.METHODS: Six validated FE models of the L3-S1 segment were reconstructed from computed tomography images, including (1) an intact model, (2)a stand-alone (SA) model with no instrument (3) a unilateral pedicle screw model (UPS), (4) a unilateral pedicle screw contralateral translaminar facet screw model (UPS-CTLFS), (5) a bilateral pedicle screw (BPS) model, and (6) a cortical bone trajectory screw (CBT).Three-dimensional model was performed by computed tomography data, and 150N static force and 10N.m moments in different directions were applied to the models to analyze the validation of the models in comparison with previous studies. Models of the OLIF cage was created with three-dimensional scanning to improve the accuracy of the FE analysis. Range of motion (ROM) of the surgical segment stresses, stress of the cage, and stress of fixation were evaluated in the different models.RESULTS:ROM increased from least to greatest as follows: BPS, UPS-CTFS, CBT, UPS, SA. The SA group had the greatest ROM and the SA group had the greatest ROM and stresses on the CAGE. The ROM of the BPS and UPS-CTFS was not significantly different for all motion loadings. Compared with the other three models, the BPS model had lower stresses in internal fixation for all loading conditions and the CBT screw internal fixation had the highest stresses for different loads Compared with the other groups.CONCLUSIONSThe BPS model provided the best biomechanical stability for OLIF. The SA model was relatively less stable. The UPS-CFTS group reduced the ROM of the fusion segments, but the stresses on the internal fixation and CAGE were relatively higher in the UPS-CFTS Compared with the BPS group; and the CBT group had lower ROM in flexion and extension Compared with the BPS, but its ROM in rotation and lateral flexion was relatively higher. The stability of the CBT was poorer than that of the BPS and LPS-CTFS groups. The stress on the CAGE and internal fixation was greater in the CBT group.

scholarly journals The Biomechanical Study of Extraforaminal Lumbar Interbody Fusion: A Three-Dimensional Finite-Element Analysis

2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Mingjie Yang ◽  
Guixin Sun ◽  
Song Guo ◽  
Cheng Zeng ◽  
Meijun Yan ◽  
...  
Keyword(s):  
Finite Element ◽  
Internal Fixation ◽  
Pedicle Screw ◽  
Interbody Fusion ◽  
Screw Fixation ◽  
Pedicle Screw Fixation ◽  
Operating Conditions ◽  
Lumbar Interbody Fusion ◽  
Unilateral Pedicle Screw Fixation ◽  
Unilateral Pedicle Screw

Objective. Finite-element method was used to evaluate biomechanics stability of extraforaminal lumbar interbody fusion (ELIF) under different internal fixation. Methods. The L3–L5 level finite-element model was established to simulate decompression and internal fixation at L4-L5 segment. The intact finite model was treated in accordance with the different internal fixation. The treatment groups were exerted 400 N load and 6 N·m additional force from motion to calculate the angular displacement of L4-L5. Results. The ROMs were smaller in all internal fixation groups than those in the intact model. Furthermore, the ROMs were smaller in ELIF + UPS group than in TLIF + UPS group under all operating conditions, especially left lateral flexion and right rotation. The ROMs were higher in ELIF + UPS group than in TLIF + BPS group. The ROMs of ELIF + UPS + TLFS group were much smaller than those in ELIF + UPS group, and as compared with TLIF + BPS group, there was no significant difference in the range of experimental loading. Discussion. The biomechanical stability of ELIF with unilateral pedicle screw fixation is superior to that of TLIF with unilateral pedicle screw fixation but lower than that of TLIF with bilateral pedicle screws fixation. The stability of ELIF with unilateral fixation can be further improved by supplementing a translaminar facet screw.

A Biomechanical Evaluation of Three Forms of Internal Fixation Used in Ankle Arthrodesis

1994 ◽  
Vol 15 (6) ◽  
pp. 297-300 ◽  
Author(s):  
Michael P. Dohm ◽  
James B. Benjamin ◽  
Jeffrey Harrison ◽  
John A. Szivek
Keyword(s):  
Internal Fixation ◽  
Plate Fixation ◽  
Ankle Arthrodesis ◽  
Biomechanical Study ◽  
The Other ◽  
Fixation Failure ◽  
Plate Group ◽  
Biomechanical Evaluation ◽  
The Stability ◽  
Fibular Strut

A biomechanical study was undertaken to evaluate the relative stability of three types of internal fixation used for ankle arthrodesis. Crossed screw fixation, RAF fibular strut fixation, and T-plate fixation were tested in 30 cadaver ankles using an MTS machine. T-plate fixation consistantly provided the stiffest construct when compared with the other types of fixation. Failure occurred by distraction of bony surfaces, posterior to the plane of fixation, in the crossed screw and RAF groups. In contrast, failure in the T-plate group occurred through compression of bone anterior to the midcoronal plane of the tibia. Although the stability of fixation is only one factor in determining the success or failure of ankle arthrodesis, the results of this study would support T-plate fixation over the other forms tested.

The Effect of Trabecular Bone on the Mechanical Response of Human Mandible with Implant

2014 ◽  
Vol 695 ◽  
pp. 588-591
Author(s):  
Khairul Salleh Basaruddin ◽  
Ruslizam Daud
Keyword(s):  
Computed Tomography ◽  
Finite Element ◽  
Trabecular Bone ◽  
Static Analysis ◽  
Load Distribution ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Fe Model ◽  
Micro Computed Tomography ◽  
Bone Specimen

This study aims to investigate the influence of trabecular bone in human mandible bone on the mechanical response under implant load. Three dimensional voxel finite element (FE) model of mandible bone was reconstructed from micro-computed tomography (CT) images that were captured from bone specimen. Two FE models were developed where the first consists of cortical bone, trabecular bone and implants, and trabecular bone part was excluded in the second model. A static analysis was conducted on both models using commercial software Voxelcon. The results suggest that trabecular bone contributed to the strength of human mandible bone and to the effectiveness of load distribution under implant load.

Structural Stability Evaluation for Lifting Lug Design of Large Marine Engine by Finite Element Analysis

2007 ◽  
Vol 353-358 ◽  
pp. 2855-2859
Author(s):  
W.C. Lee ◽  
Chae Sil Kim ◽  
J.B. Na ◽  
D.H. Lee ◽  
S.Y. Cho ◽  
...  
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Design Procedure ◽  
Steel Structures ◽  
Stability Evaluation ◽  
Element Analysis ◽  
Marine Engines ◽  
Dimensional Finite Element ◽  
The Stability ◽  
Three Dimensional Finite Element

Since most marine engines are generally very huge and heavy, it is required to keep safety from accidents in dealing them. Several types of lifting lugs have been used to assemble hundred ton–large steel structures and carry the assembled engines. Recently a few crashes have been occurred in carrying engines due to breaking down the lugs. Although the stability evaluation of the lifting lug has therefore been very important for safety, systematic design procedure of the lugs, which includes the structural analysis considering stability, has few reported. This paper describes the three dimensional finite element structural modeling for a lifting lug, the studies for determining the reasonable loading and boundary conditions, and the stability evaluation with the results of structural analyses. It should be very helpful for designing the other types of lifting lugs with safety.

scholarly journals Modeling inflatable fabric with undevelopable surfaces by motion folding method

2019 ◽  
Vol 14 ◽  
pp. 155892501988640
Author(s):  
Xiao-Shun Zhao ◽  
He Jia ◽  
Zhihong Sun ◽  
Li Yu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Numerical Study ◽  
Technical Problem ◽  
Three Dimensional ◽  
Element Model ◽  
Model Errors ◽  
Folding Model ◽  
Study Results ◽  
The Stability

At present, most space inflatable structures are composed of flexible inflatable fabrics with complex undevelopable surfaces. It is difficult to establish a multi-dimensional folding model for this type of structure. To solve this key technical problem, the motion folding method is proposed in this study. First, a finite element model with an original three-dimensional surface was flattened with a fluid structure interaction algorithm. Second, the flattened surface was folded based on the prescribed motion of the node groups, and the final folding model was obtained. The fold modeling process of this methodology was consistent with the actual folding processes. Because the mapping relationship between the original finite element model and the final folding model was unchanged, the initial stress was used to modify the model errors during folding process of motion folding method. The folding model of an inflatable aerodynamic decelerator, which could not be established using existing folding methods, was established by using motion folding method. The folding model of the inflatable aerodynamic decelerator showed that the motion folding method could achieve multi-dimensional folding and a high spatial compression rate. The stability and regularity of the inflatable aerodynamic decelerator numerical inflation process and the consistency of the inflated and design shapes indicated the reliability, applicability, and feasibility of the motion folding method. The study results could provide a reference for modeling complex inflatable fabrics and promote the numerical study of inflatable fabrics.

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