scholarly journals Biomechanical Analysis of the Tuning Fork Plate Versus Dual Pelvic Screws in a Sacrectomy Model: A Finite Element Study

2021 ◽  
pp. 219256822098379
Author(s):  
Amin Joukar ◽  
Jwalant Mehta ◽  
Vijay K. Goel ◽  
David S. Marks
Keyword(s):  
Finite Element ◽  
Tuning Fork ◽  
Screw Fixation ◽  
Plate Fixation ◽  
Biomechanical Analysis ◽  
Plate Versus ◽  
Element Analysis ◽  
Fixation Devices ◽  
Iliac Screw ◽  
Fixation System

Study Design: To evaluate the mechanical effectiveness of “tuning fork” plate fixation system by comparing with dual iliac screw fixation under different spinal motion through finite element analysis (FEA). Objective: Lumbosacral deficiencies occur from birth defects or following destruction by tumors. The objective of this study was to evaluate the mechanical effectiveness of the tuning fork plate compared to dual iliac screw system which is the gold standard fixation in treating lumbosacral deficiencies. This is an innovative fixation device for treating lumbosacral deficiencies. Methods: The deficiency model was prepared using a previously developed and validated finite element T10-pelvis model. To create the lumbo-sacral deficiency the segments between L3 and sacrum were removed from the model. The model was then instrumented from T10 to L2 segments and the ilium using either the tuning fork plate or a dual iliac screw construct. With the ilium fixed, the T10 vertebrae was subjected to 10 Nm moment and 400 N follower load to simulate spinal motions. Range of motion (ROM) of spine and stresses on the instrumentation were calculated for 2 fixation devices and compared with each other. Results: The 2 fixation systems demonstrate a comparable motion reduction in all loading modes. Stress values were higher in the dual iliac screw constructs compared with the tuning fork plate fixation system. The factor of safety of the tuning fork plate device was higher than the dual iliac screw fixation by 50%. Conclusions: Both fixation devices had similar performance in motion reduction at spine levels. However, based on predicted implant stresses there were less chances of implant failure in the fork plate fixation, compared to the dual iliac screw system.

scholarly journals A comparative biomechanical analysis of suprapectineal and infrapectineal fixation on acetabular anterior column fracture by finite element modeling

2019 ◽  
Author(s):  
MEHMET YÜCENS ◽  
KADİR BAHADIR ALEMDAROĞLU ◽  
AHMET ÖZMERİÇ ◽  
SERKAN İLTAR ◽  
AHMET ÖZGÜR YILDIRIM ◽  
...  
Keyword(s):  
Finite Element ◽  
Plate Fixation ◽  
Three Dimensional ◽  
Fracture Line ◽  
Biomechanical Analysis ◽  
Vertical Shear ◽  
Anterior Column ◽  
Fixation Method ◽  
Stable Fixation ◽  
Element Analysis

Background: The aim of this study is to compare the stability and implant stresses of suprapectineal plate with infrapectineal plate in three subconfigurations of the screw types. Methods: The stabilities of different fixation methods were compared by finite-element analysis on six models. Three infrapectineal models and three suprapectineal models each with locked, unlocked or combined screws were employed. Three-dimensional finite element stress analysis was performed by using isotropic materials with a load of 2.3 kN applied at standing positions. Motion at the fracture line was measured on four different points that are located at pubic and iliac side of the fracture line. Results: Infrapectineal plate fixation with unlocked screws was found to be the most stable fixation method with 0.006 mm displacement of fragments in all axes at standing positions. Suprapectineal unlocked method was found to be the most unstable in standing positions with maximum distraction values of 0.46 mm vertical shear movement in x-axis, -0.14 mm distraction in y-axis and -0.33 mm lateral shear in z-axis. Conclusions: To our results infrapectineal unlocked plate supplies the most stable fixation with least implant stress in contrary to the suprapectineal unlocked plate, which has the lowest stability and highest implant stresses. Keywords: Acetabular fracture; anterior column; suprapectineal; infrapectineal; fixation; finite element.

scholarly journals Retropharyngeal Reduction Plate for Treatment of Irreducible Atlantoaxial Dislocation: A Cadaveric Test and Finite Element Analysis

2020 ◽  
Author(s):  
Yukun Du ◽  
Zhao Meng ◽  
Jianyi Li ◽  
Zheng Zhao ◽  
Xiangyang Wang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Pedicle Screw ◽  
Screw Fixation ◽  
Pedicle Screw Fixation ◽  
Atlantoaxial Dislocation ◽  
Element Analysis ◽  
Irreducible Atlantoaxial Dislocation ◽  
Plate System ◽  
Fixation System

Abstract Background: Clinical studies have shown that irreducible atlantoaxial dislocation (IAAD) can achieve reduction, decompression, fixation and fusion by transoral, posterior, and other traditional approaches. The present study aims to introduced a newly designed reduction plate through the retropharyngeal approach and evaluate its feasibility by cadaveric test and finite element analysis.Methods: A cadaveric specimen and a 45-year-old postoperative female patient diagnosed with IAAD who underwent the traditional posterior fixation were enrolled in this scientific study. The retropharyngeal approach involved placing the reduction plate into a cadaveric specimen’s cervical spine. Spiral CT thinly scanning (0.05 mm) from the base of the occipital bone to C7 vertebrae was performed and reconstructed for three-dimensional (3D) finite element analysis using Mimics software based on the Dicom data of two different fixations. Biomechanical distribution was compared between two fixations under different stress conditions, including flexion, extension, bending and rotation, respectively.Results: There was no significant difference in maximum stress between the retropharyngeal reduction plate system and the posterior atlantoaxial pedicle screw fixation system during flexion. Under states of extension, bending and rotation, the maximum stress of the reduction plate system was significantly lower than that of the posterior atlantoaxial pedicle screw fixation system. Both of the maximum stresses between two fixations were far lower than the maximum yield strength (795-827 MPa) and ultimate strength (860-896 MPa) of the titanium alloys. There was no significantly stress concentration between retropharyngeal reduction plate system and the posterior atlantoaxial pedicle screw fixation system under different movement.Conclusions: The cadaveric test showed that it is feasible to place the reduction plate using the retropharyngeal approach. The finite element analysis indicated that the retropharyngeal reduction plate system may provide relatively reliable fixation compared with traditional posterior fixation. A new choice of designing a surgical plan for treating atlantoaxial dislocation is presented.

scholarly journals Biomechanical Study of Transsacral-transiliac Screw Fixation Versus Lumbopelvic Fixation and Bilateral Triangular Fixation for “H”- and “U”-type Sacrum Fractures With Traumatic Spondylopelvic Dissociation: a Finite Element Analysis Study

2021 ◽  
Author(s):  
Ye Peng ◽  
Gongzi Zhang ◽  
Shuwei Zhang ◽  
Xinran Ji ◽  
Junwei Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Screw Fixation ◽  
Standing Position ◽  
Biomechanical Study ◽  
Biomechanical Analysis ◽  
Finite Element Models ◽  
Biomechanical Stability ◽  
Element Analysis ◽  
Lumbopelvic Fixation ◽  
Biomechanical Tests

Abstract Objective: To compare the biomechanical stability of transsacral-transiliac screw fixation and lumbopelvic fixation for “H”- and “U”-type sacrum fractures with traumatic spondylopelvic dissociation.Methods: Finite element models of “H”- and “U”-type sacrum fractures with traumatic spondylopelvic dissociation were created in this study. The models mimicked the standing position of a human. Fixation with transsacral-transiliac screw fixation, lumbopelvic fixation, and bilateral triangular fixation were simulated. Biomechanical tests of instability were performed, and the fracture gap displacement, anteflexion, rotation, and stress distribution after fixation were assessed.Results: For H-type fractures, the three kinds of fixation ranked by stability were bilateral triangular fixation > lumbopelvic fixation > transsacral-transiliac screw fixation in the vertical and anteflexion directions, bilateral triangular fixation > transsacral-transiliac S1 and S2 screw fixation > lumbopelvic fixation in rotation. The largest displacements in the vertical, anteflexion and rotational directions were 0.57234 mm, 0.37923 mm and 0.13076 mm, respectively. For U-type fractures, these kinds of fixation ranked by stability were bilateral triangular fixation > lumbopelvic fixation > transsacral-transiliac S1 and S2 screw fixation > transsacral-transiliac S1 screw fixation in the vertical, anteflexion and rotational directions. The largest displacements in the vertical, anteflexion and rotational directions were 0.38296 mm, 0.33976 mm and 0.05064 mm, respectively.Conclusion: All these kinds of fixation met the mechanical criteria for clinical applications. The biomechanical analysis showed better bilateral balance with transsacral-transiliac screw fixation. The maximal displacement for these types of fixation was less than 1 mm. Percutaneous transsacral-transiliac screw fixation can be considered the best option among these kinds of fracture fixation.

scholarly journals Biomechanical study of transsacral-transiliac screw fixation versus lumbopelvic fixation and bilateral triangular fixation for “H”- and “U”-type sacrum fractures with traumatic spondylopelvic dissociation: a finite element analysis study

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Ye Peng ◽  
Gongzi Zhang ◽  
Shuwei Zhang ◽  
Xinran Ji ◽  
Junwei Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Screw Fixation ◽  
Standing Position ◽  
Biomechanical Study ◽  
Biomechanical Analysis ◽  
Finite Element Models ◽  
Biomechanical Stability ◽  
Element Analysis ◽  
Lumbopelvic Fixation ◽  
Biomechanical Tests

Abstract Objective To compare the biomechanical stability of transsacral-transiliac screw fixation and lumbopelvic fixation for “H”- and “U”-type sacrum fractures with traumatic spondylopelvic dissociation. Methods Finite element models of “H”- and “U”-type sacrum fractures with traumatic spondylopelvic dissociation were created in this study. The models mimicked the standing position of a human. Fixation with transsacral-transiliac screw fixation, lumbopelvic fixation, and bilateral triangular fixation were simulated. Biomechanical tests of instability were performed, and the fracture gap displacement, anteflexion, rotation, and stress distribution after fixation were assessed. Results For H-type fractures, the three kinds of fixation ranked by stability were bilateral triangular fixation > lumbopelvic fixation > transsacral-transiliac screw fixation in the vertical and anteflexion directions, bilateral triangular fixation > transsacral-transiliac S1 and S2 screw fixation > lumbopelvic fixation in rotation. The largest displacements in the vertical, anteflexion, and rotational directions were 0.57234 mm, 0.37923 mm, and 0.13076 mm, respectively. For U-type fractures, these kinds of fixation ranked by stability were bilateral triangular fixation > lumbopelvic fixation > transsacral-transiliac S1 and S2 screw fixation > transsacral-transiliac S1 screw fixation in the vertical, anteflexion, and rotational directions. The largest displacements in the vertical, anteflexion, and rotational directions were 0.38296 mm, 0.33976 mm, and 0.05064 mm, respectively. Conclusion All these kinds of fixation met the mechanical criteria for clinical applications. The biomechanical analysis showed better bilateral balance with transsacral-transiliac screw fixation. The maximal displacement for these types of fixation was less than 1 mm. Percutaneous transsacral-transiliac screw fixation can be considered the best option among these kinds of fracture fixation.

scholarly journals Finite element analysis of double‐plate fixation using reversed locking compression‐distal femoral plates for Vancouver B1 periprosthetic femoral fractures

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Daisuke Takahashi ◽  
Yoshihiro Noyama ◽  
Tsuyoshi Asano ◽  
Tomohiro Shimizu ◽  
Tohru Irie ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Plate Fixation ◽  
Weight Bearing ◽  
Femoral Fractures ◽  
Full Weight Bearing ◽  
Loading Test ◽  
Lateral Plate ◽  
Element Analysis ◽  
Periprosthetic Femoral Fractures

Abstract Background Internal fixation is recommended for treating Vancouver B1 periprosthetic femoral fractures. Although several fixation procedures have been developed with high fixation stability and union rates, long-term weight-bearing constructs are still lacking. Therefore, the aim of the present study was to evaluate the stability of a double-plate procedure using reversed contralateral locking compression-distal femoral plates for fixation of Vancouver B1 periprosthetic femoral fractures under full weight-bearing. Methods Single- and double-plate fixation procedures for locking compression-distal femoral plates were analysed under an axial load of 1,500 N by finite element analysis and biomechanical loading tests. A vertical loading test was performed to the prosthetic head, and the displacements and strains were calculated based on load-displacement and load-strain curves generated by the static compression tests. Results The finite element analysis revealed that double-plate fixation significantly reduced stress concentration at the lateral plate place on the fracture site. Under full weight-bearing, the maximum von Mises stress in the lateral plate was 268 MPa. On the other hand, the maximum stress in the single-plating method occurred at the defect level of the femur with a maximum stress value of 1,303 MPa. The principal strains of single- and double-plate fixation were 0.63 % and 0.058 %, respectively. Consistently, in the axial loading test, the strain values at a 1,500 N loading of the single- and double-plate fixation methods were 1,274.60 ± 11.53 and 317.33 ± 8.03 (× 10− 6), respectively. Conclusions The present study suggests that dual-plate fixation with reversed locking compression-distal femoral plates may be an excellent treatment procedure for patients with Vancouver B1 fractures, allowing for full weight-bearing in the early postoperative period.

The Optimum Cage Position and Orientation on the ALIF with Facet Screw Fixation: A Finite Element Analysis and the Taguchi Method

2011 ◽  
Vol 27 (3) ◽  
pp. 309-320 ◽  
Author(s):  
C.-Y. Fan ◽  
C.-K. Chao ◽  
C.-C. Hsu ◽  
K.-H. Chao
Keyword(s):  
Finite Element ◽  
Taguchi Method ◽  
Screw Fixation ◽  
Three Dimensional ◽  
Element Model ◽  
Lateral Position ◽  
Element Analysis ◽  
Control Factors ◽  
Position And Orientation ◽  
Noise Factors

ABSTRACTAnterior Lumbar Interbody Fusion (ALIF) has been widely used to treat internal disc degeneration. However, different cage positions and their orientations may affect the initial stability leading to different fusion results. The purpose of the present study is to investigate the optimum cage position and orientation for aiding an ALIF having a transfacet pedicle screw fixation (TFPS). A three-dimensional finite element model (ALIF with TFPS) has been developed to simulate the stability of the L4/L5 fusion segment under five different loading conditions. The Taguchi method was used to evaluate the optimized placement of the cages. Three control factors and two noise factors were included in the parameter design. The control factors included the anterior-posterior position, the medio-lateral position, and the convergent-divergent angle between the two cages. The compressive preload and the strengths of the cancellous bone were set as noise factors. From the results of the FEA and the Taguchi method, we suggest that the optimal cage positioning has a wide anterior placement, and a diverging angle between the two cages. The results show that the optimum cage position simultaneously contributes to a stronger support of the anterior column and lowers the risk of TFPS loosening.

scholarly journals Is Perpendicular Double Two-Hole Plates Fixation Superior to Single Four-Hole Plate Fixation to Treat Mandibular Symphysis Fracture?—A Finite Element Study

2021 ◽  
Vol 11 (18) ◽  
pp. 8629
Author(s):  
Li-Ren Chang ◽  
Ya-Pei Hou ◽  
Ting-Sheng Lin
Keyword(s):  
Finite Element ◽  
Plate Fixation ◽  
Mandibular Condyle ◽  
Fracture Site ◽  
Von Mises Stress ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Mandibular Symphysis ◽  
Lower Border ◽  
Von Mises

The effectiveness of a single four-hole plate (S4HP), perpendicularly oriented four-hole and two-hole plate (Per4H2HP), and perpendicularly oriented double two-hole plate (PerD2HP) for the fixation of a mandibular fracture was studied. A finite element analysis of the mandibular symphysis fractures treated with S4HP, Per4H2HP, and PerD2HP was performed. All surface nodes were fixed in the mandibular condyle region and occlusal muscle forces were applied. The maximal von Mises stress (MaxVMS) values of the plates, screws and screw holes were investigated. The displacement of the fracture site on the lower border of the mandibular symphysis was recorded. The displacement on the lower border of the fracture sites in the S4HP group was greater than that in the Per4H2HP group and the PerD2HP group. There was no eversion at the fracture site among all groups. Both the S4HP and Per4H2HP groups showed stress concentrations on the screws close to the fracture site. The MaxVMS increased when the number of screw holes on the mandibular anterior lower border decreased. The displacement of the fracture site and eversion with Per4H2HP and PerD2HP were far lower than those with S4HP. PerD2HP is a stable and green fixation technique for mandibular symphysis fractures.

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