Finite element analysis of biomechanical properties after implantation of movable artificial lumbar spine
10.3760/cma.j.cn501098-20201028-00652
- VernacularTitle:可动人工腰椎置入后的生物力学性能有限元分析
- Author:
Yanbiao WANG
1
;
Jun CHEN
;
Jingyi ZHANG
;
Chen CAO
;
Jialin WANG
;
Binfeng LIU
;
Bo ZHANG
;
Xiaoyu LIAN
;
Yanzheng GAO
Author Information
1. 河南省人民医院脊柱脊髓外科，450003
- Keywords:
Lumbar vertebrae;
Spinal fractures;
Zygapophyseal joint;
Finite element analysis;
Prosthesis
- From:
Chinese Journal of Trauma
2021;37(1):37-43
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the effect in lumbar mobility and stress of the facet joint and end plate after implantation of the movable artificial lumbar spine so as to lay a biomechanical foundation for its clinical application.Methods:Total lumbar CT data of a healthy adult male were selected to construct a finite element analysis model and its effectiveness was validated (physiological group). Two groups were replicated after removing the L 3 vertebral body and adjacent discs of the model in physiological group. One group was placed with each component of the movable artificial lumbar spine to construct the non-fusion model (non-fusion group). The other group was placed with titanium cage, titanium plate and other to construct the fusion model (fusion group). The models in the three groups were loaded with 500 N axial load and 10 Nm axial load, and the torque load was used to simulate the movement in six directions: forward flexion, backward extension, left and right lateral bending, and left and right torsion. The lumbar mobility and stress peak and distribution of the proximal facet joints (J 1-2, J 4-5), L 2 inferior endplate and L4 superior endplate at the three model operating sites (L 2-3, L 3-4) and adjacent segments (L 1-2, L 4-5) under the same conditions were compared. Results:The range of motions of the surgical site in flexion, extension, left bending, right bending, left torsion and right torsion were L 2-3of 3.9°-8.7° and L 3-4 of 3.6°-8.4° in non-fusion group, significantly increased compared with fusion group (L 2-3 0.1°-0.2°, L 3-4 0.1°-0.1°) and slightly increased compared with physiological group (L 2-3 2.3°-6.0°, L 3-4 2.3°-7.1°). The range of motions of the adjacent segments in the above six directions were L 1-2 of 1.4°-4.3° and L 4-5 of 1.4°-6.0° in non-fusion group, smaller than those in fusion group (L 1-2 2.1°-6.1°, L 4-5 3.3°-8.6°) and similar to those in physiological group (L 2-3 2.3°-6.0°, L 3-4 2.3°-7.1°). The peak values of von Mises stress in the proximal facet joints were J 1-2 of 7.07-19.21 MPa and J 4-5of 6.12-12.99 MPa in non-fusion group, similar to those in physiological group (J 1-2 8.42-18.53 MPa, J 4-5 7.49-11.70 MPa) and smaller than those in fusion group (J 1-2 10.54-21.16 MPa, J 4-5 10.63-16.13 MPa). The maximum von Mises stress of the L 2 inferior endplate and L 4 superior endplate in the above six directions was 29.39-54.72 MPa and 32.31-47.87 MPa in non-fusion group, significantly increased compared with the L 2 inferior endplate (21.20-42.07 MPa), L 4 superior endplate (22.50-36.76 MPa) and L 2 inferior endplate (11.04-29.55 MPa) in fusion group and the L 4 superior endplate (13.12-21.32 MPa) in physiological group. Conclusion:Compared with the traditional fusion prostheses, the placement of the movable artificial lumbar spine can reconstruct the range of motion of the surgical site in the direction of flexion, extension, lateral bending and torsion, greatly reduce the impact on the stress of adjacent facet joints and the range of motion of adjacent segments, and theoretically reduce the incidence of prosthesis subsidence.
