Biomechanical Analysis of Atlantoaxial Dorsal Fixation Using Finite Element Models

Abstract Background: Atlantoaxial instability can cause spinal cord compression with clinical signs ranging from cervical pain to tetraplegia and death. Although a variety of dorsal fixation techniques have been described, some of them have been related to the fracture of the dorsal arch of the atlas, leading to surgical failure. We hypothesized that the shape of the dorsal arch of the atlas and types of implants might affect these bone fractures. Thus, the objective of this study was to analyze bone stresses through simulations of the dorsal fixation using finite element models.Results: The width between wires and the length of the bone did not affect the maximum stress on the bone. The maximum bone stress increased as the bone got thinner and the angle of the notch got steeper. The bone with band implant had lower maximum bone stress than that with wire implants. When using wire implants, wires applied beyond the notch of the dorsal arch reduced the maximum bone stress more than wires positioned within it.Conclusions: The fracture of the dorsal arch of the atlas was related to the shape of the bone and types of implant applied. Band implant can effectively reduce the fracture of the dorsal arch compared to wire implant in atlantoaxial dorsal fixation. When considering wire implant, it is recommended to apply wires beyond the notch of the atlas.

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Biomechanical analysis for five fixation techniques of Pauwels-III fracture by finite element modeling

Computer Methods and Programs in Biomedicine ◽

10.1016/j.cmpb.2020.105491 ◽

2020 ◽

Vol 193 ◽

pp. 105491 ◽

Cited By ~ 1

Author(s):

Matthew Jian-Qiao Peng ◽

HongWen Xu ◽

Hai-Yan Chen ◽

Ze Lin ◽

XinXu Li ◽

...

Keyword(s):

Finite Element ◽

Finite Element Modeling ◽

Biomechanical Analysis ◽

Element Modeling ◽

Fixation Techniques

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Biomechanical analysis of the thoracolumbar spine under physiological loadings: Experimental motion data corridors for validation of finite element models

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1177/0954411917719740 ◽

2017 ◽

Vol 231 (10) ◽

pp. 975-981

Author(s):

Marien Couvertier ◽

Arnaud Germaneau ◽

Mathieu Saget ◽

Jean-Christophe Dupré ◽

Pascal Doumalin ◽

...

Keyword(s):

Finite Element ◽

Thoracolumbar Spine ◽

Biomechanical Analysis ◽

Finite Element Models ◽

Motion Data

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An Optimization Study of the Screw Orientation on the Interfacial Strength of the Anterior Lumbar Plate System Using Neurogenetic Algorithms and Experimental Validation

Journal of Biomechanical Engineering ◽

10.1115/1.4028412 ◽

2014 ◽

Vol 136 (11) ◽

Cited By ~ 2

Author(s):

Chian-Her Lee ◽

Ching-Chi Hsu ◽

Dinh Cong Huy

Keyword(s):

Finite Element ◽

Three Dimensional ◽

Interfacial Strength ◽

Cord Compression ◽

Finite Element Models ◽

Clinical Complications ◽

Optimization Study ◽

Plate Design ◽

Dimensional Finite Element ◽

Three Dimensional Finite Element

Anterior lumbar plate (ALP) systems have been widely used as an effective interbody fusion device for treating spinal cord compression. However, clinical complications, such as implant loosening and breakage, still occur. Past studies have investigated the effects of the screw orientation on the interfacial strength, but these studies were inconsistent. The purpose of this study was to identify an ALP system with excellent interfacial strength by varying the screw orientation. Three-dimensional finite element models of L4–L5 segments with an ALP system were first constructed. A neurogenetic algorithm, which combines artificial neural networks and genetic algorithms, was subsequently developed to discover the optimum plate design. Finally, biomechanical tests were conducted to validate the results of the finite element models and the engineering algorithm. The results indicated that the interfacial strength of the optimum plate design obtained using the neurogenetic algorithm was excellent compared with the other designs and that all of the locking screws should be inserted divergently. Both the numerical and experimental outcomes can provide clinical suggestions to surgeons and help them to understand the interfacial strength of ALP systems in terms of the screw orientation.

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EVALUATING THE EFFECT OF VARIOUS MENISCAL ATTACHMENTS AND MATERIAL PROPERTIES ON FEMORAL BONE STRESS

Journal of Musculoskeletal Research ◽

10.1142/s0218957718500033 ◽

2018 ◽

Vol 21 (01) ◽

pp. 1850003

Author(s):

Lance L. Frazer ◽

Kenneth J. Fischer

Keyword(s):

Finite Element ◽

Material Property ◽

Material Properties ◽

Finite Element Models ◽

Femoral Bone ◽

Bone Stress ◽

Stifle Joint ◽

Meniscal Attachments ◽

Property Changes ◽

The Relationship

In this paper, several finite element models of an equine stifle joint with varying meniscal properties and attachments are compared to understand the effects of meniscal attachment complexity and material property changes on bone stresses. We found that the complexity in the meniscal attachment is critical when evaluating tensile stresses in the bone. We also demonstrate that simplified material properties may be justified when the relationship between each material property and the desired output variables is well understood. The choice of the most efficient, and yet appropriate, meniscal modeling method depends on the goals of the model.

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Biomechanical Analysis of a Long-Segment Fusion in a Lumbar Spine—A Finite Element Model Study

Journal of Biomechanical Engineering ◽

10.1115/1.4039989 ◽

2018 ◽

Vol 140 (9) ◽

Cited By ~ 6

Author(s):

Raghu N. Natarajan ◽

Kei Watanabe ◽

Kazuhiro Hasegawa

Keyword(s):

Finite Element ◽

Lumbar Spine ◽

Posterior Instrumentation ◽

Spinal Instrumentation ◽

Element Model ◽

Biomechanical Analysis ◽

Spinal Stabilization ◽

Rod System ◽

Fixation Techniques ◽

Materials Used

Examine the biomechanical effect of material properties, geometric variables, and anchoring arrangements in a segmental pedicle screw with connecting rods spanning the entire lumbar spine using finite element models (FEMs). The objectives of this study are (1) to understand how different variables associated with posterior instrumentation affect the lumbar spine kinematics and stresses in instrumentation, (2) to compare the multidirectional stability of the spinal instrumentation, and (3) to determine how these variables contribute to the rigidity of the long-segment fusion in a lumbar spine. A lumbar spine FEM was used to analyze the biomechanical effects of different materials used for spinal rods (TNTZ or Ti or CoCr), varying diameters of the screws and rods (5 mm and 6 mm), and different fixation techniques (multilevel or intermittent). The results based on the range of motion and stress distribution in the rods and screws revealed that differences in properties and variations in geometry of the screw-rod moderately affect the biomechanics of the spine. Further, the spinal screw-rod system was least stable under the lateral bending mode. Stress analyzes of the screws and rods revealed that the caudal section of the posterior spinal instrumentation was more susceptible to high stresses and hence possible failure. Although CoCr screws and rods provided the greatest spinal stabilization, these constructs were susceptible to fatigue failure. The findings of the present study suggest that a posterior instrumentation system with a 5-mm screw-rod diameter made of Ti or TNTZ is advantageous over CoCr instrumentation system.

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Biomechanical analysis of the annular ligament in Monteggia fractures using finite element models

Journal of Orthopaedic Surgery and Research ◽

10.1186/s13018-015-0170-3 ◽

2015 ◽

Vol 10 (1) ◽

pp. 30 ◽

Cited By ~ 2

Author(s):

Jiangwei Tan ◽

Mingzhang Mu ◽

Guangjun Liao ◽

Yong Zhao ◽

Jianmin Li

Keyword(s):

Finite Element ◽

Biomechanical Analysis ◽

Annular Ligament ◽

Finite Element Models

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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

10.21203/rs.3.rs-472072/v1 ◽

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.

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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

Journal of Orthopaedic Surgery and Research ◽

10.1186/s13018-021-02581-5 ◽

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.

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