绵羊腰椎植入PA66/n-HA融合器后的初始稳定性研究

【作者】 刘枫；

【导师】 王以朋；

【作者基本信息】 北京协和医学院 ， 临床医学， 2010， 博士

【摘要】 背景：具有良好生物活性和生物力学性能的材料可制成各种器械植入体内,取代老式器械,取得更好的临床效果,应用前景广泛。目的：利用PA66/n-HA复合材料试制适用于绵羊腰椎的融合器,比较植入双枚或者单枚融合器后,绵羊腰椎的初始稳定性,并借助有限元分析其应力、应变情况。材料方法：使用CT扫描绵羊腰椎并结合MIMICS软件确定融合器尺寸,设计并制造本实验使用的融合器；把绵羊腰椎分别植入两枚、单枚融合器,并以自体植骨组为对照进行体外实验,测试三种处理方式在有钉棒固定和无钉棒固定下的初始稳定性；利用绵羊腰椎CT扫描的数据,使用MIMICS和ANSYS软件进行三维有限元法进行应力应变的分析。结果：利用新材料设计并制造了适用于绵羊腰椎的两种型号的融合器；体外试验结果提示植入融合器节段的初始稳定性在对抗压缩载荷方面比自体植骨具有明显优势,植入两枚融合器比植入一枚融合器可能更稳定。有限元模型的计算结果和实验测量结果比较吻合,说明模型具有一定的可信度,其应力应变分布的分析也有助于我们深入理解融合术后椎体的力学改变。结论：使用PA66/n-HA复合材料制作的融合器植入椎间隙后的初始阶段,其脊柱单元比采用自体植骨的脊柱单元更稳定,若进一步研发,可望投入临床使用。更多还原

【Abstract】 Back ground:The materials with excellent Biological activity and biomechanical properties can be made into various kinds of implants, and they can achieve better clinical results, so they can replace old equipments and have broad application prospects.Objective:(1)To make cages for sheep lumbar by PA66/n-HA material.(2) To compare the primary lumbar segment stability when one cage or two cages implanted.(3) Analysis the Stress and strain of lumbar vertebrae by finite element analysis.Materials and methods:(1) Achieved the size of sheep lumbar vertebrae by CT scan and determined the size of cages by MIMICS, then designed and made the cages for this study.(2)Compared the primary lumbar segment stability of one cage, two cages and Autologous bone graft groups, with or without screw fixation.(3)Analyzed the Stress and strain of lumbar vertebrae by finite element analysis.Results:(1) Designed and produced two types of cages for sheep lumbar.(2) In vitro tests suggested that cages provide better stability than Autologous bone graft, especially two cages.(3) Some results of finite element analysis is similar to the mechanical tests quantitatively. Finite element analysis can make better understanding of mechanical changes in vertebral body after fusion.Conclusion:Cages made of PA66/n-HA could provide better primary lumbar segment stability than Autologous bone graft, and with more studies, they may be used in clinics.更多还原