A three-dimensional finite element analysis of correlations between stress distribution and fracture in the thoracolumbar spine
10.3969/j.issn.1004-406X.2024.04.10
- VernacularTitle:脊柱胸腰段应力分布与骨折相关性的三维有限元分析
- Author:
Fei YUAN
1
,
2
;
Jie REN
;
Yuefeng TANG
Author Information
1. 贵州医科大学临床医学院 550004 贵阳市
2. 贵州省人民医院骨科 550499 贵阳市
- Keywords:
Vertebral body fracture;
Thoracolumbar spine;
Three-dimensional finite element model;
Stress analysis
- From:
Chinese Journal of Spine and Spinal Cord
2024;34(4):408-417
- CountryChina
- Language:Chinese
-
Abstract:
Objectives:To observe and analyze the relationship between thoracolumbar vertebral fractures and vertebral bone structure,as well as stress distribution within ligaments,in order to explore the mechanical mechanisms underlying thoracolumbar vertebral fractures.Methods:Eight healthy young male volunteers were recruited for the study.X-ray and CT examinations of the entire spine were conducted to rule out spinal deformity,tumor,and bone disease.Bone mineral density(BMD)measurements were taken for each vertebral body and femur to exclude osteoporosis.CT thin layer scan was performed from the upper endplate of T11 to lower edge of L2 vertebra,and the CT image parameters were imported to ABAQUS 2016 software to standardize and perform finite element mesh construction.The thoracolumbar spine finite element model was developed using MIMICS 17.0,GEOMAGICS 15.0,and PRO/ENGINEER 5.0 softwares to measure relevant parameters,and its efficacy was validated.Seven motion states,including vertical compression,flexion,extension,left and right lateral bending,and left and right rotation,were simulated.ABAQUS software was employed to analyze stress distribution patterns and variations in the seven motion states of the finite element model,allowing for the observation of the relationship between stress distribution and thoracolumbar fracture.Results:The validated three-dimensional finite element model utilized in this study consisted of 309,583 nodes and 428,760 elements,encompassing anatomical structures such as four vertebral bodies,three intervertebral discs,and various ligaments including the anterior longitudinal ligament,posterior longitudinal ligament,intertransverse ligament,and interspinous ligament.Analysis of the data across seven different motion states revealed no significant deviations from the findings reported by other literature,confirming the accuracy and reliability of the model.The cross-sectional areas of T11-L2 pedicle were 135mm2,154mm2,105mm2,and 139.2mm2,respectively.High stress areas presented within the cancellous bone of the vertebral body,the pedicle and surrounding cortex of the vertebral body during various states of motion according to the stress cloud map analysis.Specifically,the T12 vertebral body exhibited the highest stress level(617.4MPa)under vertical compression,while the T11 vertebral body experienced the highest stress level(200.7MPa)during forward flexion.Additionally,the maximum stress levels recorded for the L1 vertebral body were 314.2MPa,574.4MPa,626.2MPa,641.3MPa,and 527.1MPa during extension,left and right lateral bending,and left and right rotation,respectively.The stress experienced by the L1 vertebral body was found to be minimal in the flexion position and maximal in the left rotation position.T12 vertebral fracture was observed under vertical compression,while T11 vertebral fracture occurred during flexion.L1 vertebral fracture,in combination with ligament injury,was observed during extension,left and right lateral bending,and left and right rotation.High stress areas were identified in anterior longitudinal ligament during extension and left and right lateral bending and in posterior longitudinal ligament during flexion.High stress areas were observed in the intertransverse and interspinous ligaments during movements involving forward flexion,left and right lateral bending,and left and right rotation.Conclusions:In the three-dimensional model of thoracolumbar spine,in-corporating key ligaments,intervertebral discs,and other soft tissue structures,notable areas of high stress were identified within the cancellous bone of vertebral body,pedicle and surrounding cortical bone,and liga-ments.Variations in maximum stress levels were observed in vertebral body under different conditions,result-ing in varying degrees of vertebral body fracture and ligament injury;L1 pedicle exhibited the smallest cross-sectional area and was prone to fracture.
