Finite element analysis of locking axial lumbosacral interbody fusion cage

doi:10.3969/j.issn.2095-4344.0856

Abstract

Abstract:

BACKGROUND: In order to improve lumbosacral stability and fusion, we developed a locking axial lumbosacral fusion cage for Chinese lumbosacral vertebrae.

OBJECTIVE: To establish an effective three-dimensional finite element model of axial lumbosacral interbody fusion with locking plate and to analyze the stress distribution of the screw under different loads, and to provide targets and evaluation indexes to be improved.

METHODS: A normal adult lumbosacral vertebra finite element model was established by reverse engineering software Mimics and Geomagic. The locking axial lumbosacral fusion cage was assembled into the effective lumbosacral vertebra model by simulating the surgical procedure. The mesh model was divided into two groups. A finite element mesh model of lumbosacral vertebrae fitted with the locking axial fusion cage was established. According to the material properties of lumbosacral vertebrae and fusion cages, the model was assigned and imported into SolidWorks 2011 to obtain the final finite element model. Under physiological and ultimate loads, the model was subjected to flexion, extension, lateral bending and rotation motions. The stress distribution in the axial-direction cage with locking was completed by Hypermesh software to evaluate its biomechanical properties.

RESULTS AND CONCLUSION: The maximal compressive force of the locking axial lumbosacral fusion cage under the vertical compression+flexion+left-handed condition was 1 500.08 MPa, and the stress concentration point was located at the left and right sides of the bone hole. Then, under the vertical compression+flexion+right-hand limit load, the maximum pressure to be absorbed by the fusion cage was 1 318.00 MPa, and the stress concentration point was at the left and right sides of the bone hole, and there was a lower pressure at the upper and lower sides of the bone hole. Physiological load holders provide adequate strength, stability and bone-graft fusion. Under vertical compression+flexion+rotation conditions, the maximum stress exceeds the yield strength of the screw. Therefore, to improve the process and strengthen the weak points of bone graft, postoperative early bed rest, wearing a brace, and to avoid over-stretch, flexion or torsion and other high strength movement are recommended.

中国组织工程研究杂志出版内容重点：人工关节；骨植入物；脊柱；骨折；内固定；数字化骨科；组织工程

Key words: Internal Fixators, Lumbar Vertebrae, Finite Element Analysis, Tissue Engineering

CLC Number:

R318

Yi Xin, Song Xi-zheng . Finite element analysis of locking axial lumbosacral interbody fusion cage[J]. Chinese Journal of Tissue Engineering Research, 2018, 22(31): 4982-4986.

Figures/Tables 2

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