CAJ | 학술논문

背景:由于脊柱结构复杂,对复位或原位融合后融合的腰椎节段应力分布变化特点的精确生物力学分析一直是个难点.目的:通过建立 L4/5节段退变性滑脱原位椎间融合椎弓根钉内固定和复位椎间融合椎弓根钉内固定的三维有限元模型来比较腰椎滑脱原位融合和复位融合两种手术方式在各种载荷下的生物力学变化及其对腰椎稳定的影响.方法:根据健康成年男性的下腰椎 CT 数据,利用 mimics,Catia 和 Patran,Marc 等软件建立起 L4/5节段的三维有限元模型,利用此模型模拟退变性腰椎滑脱,在此基础上建立 L4/5节段原位椎间融合椎弓根钉内固定和复位椎间融合内固定模型,分析两模型在各种载荷下的应力分布特点,并比较异同.结果与结论:L4/5节段退变性滑脱原位椎间融合椎弓根钉内固定和复位椎间融合椎弓根钉内固定三维有限元模型在前屈后伸侧屈旋转负荷下,该节段各部结构,包括椎体,椎弓根钉内固定器和椎间融合器上的应力变化没有显著差异.两模型都显示椎间融合器和椎弓根螺钉内固定器上分布的应力最大.结果表明退变性腰椎滑脱,行原位椎间融合内固定和复位椎间融合内固定后,复位与否对该节段生物力学没有显著影响.
배경:유우척주결구복잡,대복위혹원위융합후융합적요추절단응력분포변화특점적정학생물역학분석일직시개난점.목적:통과건립 L4/5절단퇴변성활탈원위추간융합추궁근정내고정화복위추간융합추궁근정내고정적삼유유한원모형래비교요추활탈원위융합화복위융합량충수술방식재각충재하하적생물역학변화급기대요추은정적영향.방법:근거건강성년남성적하요추 CT 수거,이용 mimics,Catia 화 Patran,Marc 등연건건립기 L4/5절단적삼유유한원모형,이용차모형모의퇴변성요추활탈,재차기출상건립 L4/5절단원위추간융합추궁근정내고정화복위추간융합내고정모형,분석량모형재각충재하하적응력분포특점,병비교이동.결과여결론:L4/5절단퇴변성활탈원위추간융합추궁근정내고정화복위추간융합추궁근정내고정삼유유한원모형재전굴후신측굴선전부하하,해절단각부결구,포괄추체,추궁근정내고정기화추간융합기상적응력변화몰유현저차이.량모형도현시추간융합기화추궁근라정내고정기상분포적응력최대.결과표명퇴변성요추활탈,행원위추간융합내고정화복위추간융합내고정후,복위여부대해절단생물역학몰유현저영향.
BACKGROUND: Due to the complexity of the spinal structure, it is difficult to conduct the exact biomechanical analysis on the changes of the stress distribution characteristics of the lumbar segment after in situ and reductive interbody fusion. OBJECTIVE: To compare the biomechanical changes of in situ and reductive interbody fusion of lumbar spondylolisthesis under mechanical loads and the effect of those changes on the lumbar stability through developing the three-dimensional finite element models of L4/5 degenerative spondylolisthesis treated with in situ and reductive interbody fusion pedicle screw internal fixation. METHODS: The three-dimensional finite element models of L4/5 segment of healthy male volunteers were established through analyzing the lower lumbar spine CT data and using the mimics, Catia, Patran and Marc softwares. Then the models were used to simulate the degenerative spondylolisthesis and to establish the L4/5 segment in situ and reductive interbody fusion and pedicle screw internal fixation models. The stress distribution characteristics of these two models under different mechanic loads were analyzed and the difference was compared. RESULTS AND CONCLUSION: Under the loads of flexion, extension, right rotation and left bending, there was no significant difference of the stress on the vertebral body, pedicle screw fixator and interbody fusion cage between the L4/5 segment degenerateive spondylolisthesis in situ and reductive interbody fusion and pedicle screw internal fixation models. Both the two models manifested that the pedicle screw fixator and interbody fusion cage take the majority of the loads. After the in situ and reductive interbody fusion internal fixation for the degenerative spondylolisthesis of the L4/5 segment, reduction or not has no great biomechanical influence on the fusion segment.