摘要
背景:单边双通道内镜下腰椎椎间融合作为新颖的微创技术已被广泛应用于腰椎退行性疾病的治疗,但融合器沉降作为一种术后并发症仍无法完全避免。目的:通过有限元模型分析单边双通道内镜下腰椎椎间融合技术的生物力学特点,以及在不同高度融合器和骨质疏松条件下融合器沉降的风险。方法:基于健康成年男性志愿者的CT数据构建了L_(4)-L_(5)椎体有限元模型,依据单边双通道内镜下腰椎椎间融合手术方式,依次构建置入8,10,12 mm 3种不同高度融合器的模型,每种高度融合器模型分为骨质正常和骨质疏松两种情况。在L_(4)上表面施加500 N的随动载荷和10 Nm的力矩,模拟前屈、后伸、左侧弯、右侧弯、左旋转、右旋转运动,观察并分析不同工况下各种模型的相对活动度、椎弓根钉-杆系统应力及终板应力。结果与结论:(1)在相同运动状态下,6种椎间融合模型的相对活动度均明显低于正常腰椎模型;6种椎间融合模型前屈运动下的相对活动度最大,后伸运动下的相对活动度最小;在相同骨质与运动状态下,随着融合器高度的增加,椎间融合模型的相对活动度减少;(2)在相同骨质与运动状态下,随着融合器高度的增加,椎间融合模型的椎弓根钉-杆系统应力减小;6种椎间融合模型侧弯运动下的椎弓根钉-杆系统应力最大,前屈和后伸运动下的椎弓根钉-杆系统应力最小;当融合器高度相同时,骨质疏松模型椎弓根钉-杆系统应力均大于骨质正常模型;(3)在相同骨质与运动状态下,随着融合器高度的增加,椎间融合模型的L_(4)下终板(或L_(5)上终板)最大应力增加;当融合器高度相同时,骨质疏松模型的L_(4)下终板(或L_(5)上终板)最大应力稍大于骨质正常模型;在相同运动状态下,6种椎间融合模型的L_(4)下终板最大应力均大于L_(5)上终板;6种椎间融合模型前屈运动下的L_(4)下终板(或L_(5)上终板)最大应力最大,后伸运动下的L_(4)下终板(或L_(5)上终板)最大应力最小;(4)结果显示,融合器选择并不是越高越好,而是需要适度撑开,在保证节段稳定性的同时避免融合器过高导致融合器沉降的风险增加。
BACKGROUND:Unilateral biportal endoscopic lumbar interbody fusion as a novel minimally invasive technique has been widely used in the treatment of lumbar degenerative diseases.However,as a postoperative complication,fusion cage subsidence cannot be completely avoided.OBJECTIVE:To analyze the biomechanical characteristics of unilateral biportal endoscopic lumbar interbody fusion technology by establishing a finite element model,as well as the risk of fusion cage subsidence under different heights of the fusion cage and osteoporosis conditions.METHODS:Based on the CT data of healthy adult male volunteers,the finite element models of the L_(4)-L_(5) vertebral body were constructed.According to the unilateral biportal endoscopic lumbar interbody fusion operation method,the models with different cage heights of 8,10 and 12 mm were successively constructed(normal bone and osteoporosis).The flexion,extension,right lateral bend,left lateral bend,right axial rotation,and left axial rotation motions were simulated in models with different bone conditions on the upper surface of L_(4) with 500 N follower-load and 10 Nm torsional torque.The range of motion,pedicle screw-rod system stress and endplate stress of each model under different working conditions were observed and analyzed.RESULTS AND CONCLUSION:(1)Under the same motion state,the range of motion of the six kinds of lumbar fusion models was significantly lower than that of the normal lumbar model.The range of motion of six kinds of interbody fusion models was the largest under flexion and the smallest under extension.With the increase in cage height,the range of motion of the intervertebral fusion model decreased under the same bone and motion conditions.(2)Under the same bone and motion conditions,with the increase in cage height,the stress of the pedicle screw rod system of interbody fusion model decreased.The stress of pedicle screw rod system in six kinds of interbody fusion models was the highest under lateral bending movement and the lowest under flexion and extension.When the height of the fusion cage was the same,the stress of the pedicle screw rod system in the osteoporosis model was greater than that in the normal model.(3)Under the same bone and motion conditions,with the increase of cage height,the maximum stress of the L_(4) lower endplate(or L_(5) upper endplate)of the intervertebral fusion model increased.When the height of the fusion cage was the same,the maximum stress of the L_(4) lower endplate(or L_(5) upper endplate)in the osteoporosis model was slightly greater than that in the normal model.Under the same motion state,the maximum stress of the L_(4) lower endplate was greater than that of the L_(5) upper endplate in six kinds of intervertebral fusion models.The maximum stress of the L_(4) lower endplate(or L_(5) upper endplate)under the flexion was the largest and the maximum stress of the L_(4) lower endplate(or L_(5) upper endplate)under the extension was the smallest.(4)The results show that the higher the fusion cage is,the better it is,but it needs to be properly stretched to ensure the stability of the segment and avoid the increased risk of fusion cage subsidence caused by too high fusion cage.
作者
李嘉睿
燕杨
武晓刚
冯皓宇
何李明
Li Jiarui;Yan Yang;Wu Xiaogang;Feng Haoyu;He Liming(The Third Hospital of Shanxi Medical University(Shanxi Bethune Hospital,Shanxi Academy of Medical Sciences,Tongji Shanxi Hospital),Taiyuan 030032,Shanxi Province,China;College of Biomedical Engineering,Taiyuan University of Technology,Taiyuan 030024,Shanxi Province,China)
出处
《中国组织工程研究》
CAS
北大核心
2023年第34期5523-5529,共7页
Chinese Journal of Tissue Engineering Research
基金
山西省卫生健康委,山西省医学科技创新团队建设计划,老年脊柱退变及损伤疾病诊疗科技培育团队(2020TD13),项目负责人:冯皓宇。
关键词
腰椎
单边双通道内镜
椎间融合
骨质疏松
有限元分析
生物力学
lumbar
unilateral biportal endoscopic
lumbar interbody fusion
osteoporosis
finite element analysis
biomechanics
