Finite element analysis of biomechanical effect of annulus fibrosus suture on the lumbar spine after microendoscopic discectomy
10.3969/j.issn.1004-406X.2025.09.07
- VernacularTitle:内镜辅助下髓核摘除术后纤维环缝合对腰椎生物力学影响的有限元分析
- Author:
Ming BAI
1
;
Heping YIN
1
;
Shuwen LI
1
Author Information
1. 内蒙古医科大学第二附属医院脊柱外科中心 010030呼和浩特市
- Publication Type:Journal Article
- Keywords:
Annulus fibrosus suture;
Finite element analysis;
Biomechanics
- From:
Chinese Journal of Spine and Spinal Cord
2025;35(9):948-955
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the effects of annulus fibrosus(AF)suture or not on the lumbar biome-chanics following microendoscopic discectomy(MED)through establishing finite element models(FEMs)of unsu-tured AF incision and sutured AF incision.Methods:A 27-year-old healthy young adult male volunteer was recruited and underwent lumbar CT to exclude spinal deformities,tumors,and other osseous pathologies.CT images of the L4/L5 segment were imported into the software Mimics for three-dimensional reconstruction and contour extraction.The resulting model was further processed using Geomagic,SolidWorks,and Workbench for solid modeling.An intact L4/5 segment model,an L4/5 model with an unsutured AF incision following MED(unsutured AF model),and an L4/5 model with a sutured AF incision following MED(sutured AF model)were established.Intervertebral range of motion(ROM),Von-Mises stress on the facet joints,and Von-Mises stress on the AF of the models were measured,and model validity was verified by comparison with previously pub-lished studies.After validation,the inferior end of the L5 vertebral body in all the three models was fixed.An axial load of 500N was applied to the superior end of the L4 vertebral body,and a bending moment of 7.5N·m was separately applied under six physiological loading conditions(flexion,extension,left/right lateral bending,and left/right axial rotation).The biomechanical properties of the three models at the L4/5 level,in-cluding intervertebral ROM and Von-Mises stress in facet joints,and Von-Mises stress on the AF were com-pared under different loading conditions.Results:No significant discrepancies were noted when data obtained under these six motion conditions were compared with the findings from prior literature,thus validating the models.Stress nephogram results revealed that under each motion condition,high-stress areas were located at the unsutured defect of the intervertebral disc AF and the surrounding facet joint processes.Compared with the intact model,the intervertebral ROM of the sutured AF model was 8.6802°,8.596°,4.8514°,5.0249°,2.2474°,and 1.9092°,respectively,under the six motions,while that of the unsutured AF model was 8.7475°,8.9453°,5.6441°,5.2546°,2.5886°,and 1.9487°,respectively.The ROM of the sutured AF model was 9％,19％,44％,38％,50％,and 40％higher than that of the intact model;Compared with the unsutured AF mod-el,it was reduced by 1％,4％,14％,4％,13％,and 2％respectively.For Von Mises stress on the AF under the six motion conditions,the stress of the sutured AF model was 2％,65％,21％,32％,51％,and 38％higher than that of the intact model,but 8％,48％,52％,10％,37％,and 48％lower than that of the unsu-tured AF model respectively.For Von-Mises stress in facet joints,the stress values of the sutured AF model were 12.109MPa,8.3601MPa,13.998MPa,12.969MPa,10.219MPa,and 10.074MPa respectively,while those of the unsutured AF model were 13.399MPa,9.6094MPa,18.175MPa,17.967MPa,12.409MPa,and 11.6384MPa respectively.The stress values of Von-Mises stress in facet joints of the sutured AF model was 5％,10％,32％,17％,31％,and 34％higher than that of the intact model;Compared with the unsutured AF model,it was decreased by 9％,13％,22％,27％,17％,and 13％respectively.Conclusions:Among the three con-structed L4/5 FEMs,the sutured AF model exhibits more favorable intervertebral ROM,and Von-Mises stress of facet joints and AF compared with the unsutured AF model.This indicates that AF suture contributes to enhancing intervertebral stability.
