基于有限元分析腰椎内固定的生物力学特征  

Biomechanical characteristics of lumbar vertebra fixation based on finite element analysis

作　　者：陶勇[1] 吴云乐 宗少晖[1] 李柯柯[1] 杜力[1] 彭小明[1] 施雄志 胡溪源 

机构地区：[1]广西医科大学第一附属医院脊柱骨病外科,广西壮族自治区南宁市530000

出　　处：《中国组织工程研究》2016年第13期1932-1938,共7页Chinese Journal of Tissue Engineering Research

摘　　要：背景:后路椎板切除常使脊柱稳定性丧失,故术中多需要使用钉棒内固定技术维持腰椎稳定性。利用有限元分析可以模拟脊柱修复术后脊柱及内固定系统受力情况。目的:构建脊柱腰椎L_1-L_3三维有限元模型,运用三维有限元方法分析全椎板切除及双侧椎弓根螺钉置入后脊柱稳定性变化和应力分布情况。方法:采集1例成年健康男性志愿者L_1-L_3 CT数据,应用Mimics14.01、3-matic(V6.0)、Ansys 15.0等软件构建L_1-L_3完整有限元模型(A组)、L_2行全椎板切除后L_1-L_3有限元模型(B组)、L_2全椎板切除后双侧单节段椎弓根螺钉内固定系统有限元模型(C组)。模拟腰椎行前屈、后伸、侧弯及旋转,分别对3个模型进行有限元分析。结果与结论:1根据不同运动状态下的Von Mises最大应力比较可知,B组最大应力大于A组(P<0.05),C组最大应力大于B组(P<0.05)。2根据不同运动状态下的最大位移可知,B组最大位移大于A组(P<0.05),C组最大位移小于A、B组(P<0.05)。3提示椎板切除后椎体局部受力增加,尤以椎板、椎弓根及关节处增加明显,椎体活动范围增加,影响椎体稳定性;内固定可使椎体活动度减小,使腰椎应力集中于螺钉,椎板及椎弓根应力减小,椎体稳定性增加。过大的应力集中于钉棒系统会增加断钉风险。BACKGROUND： Posterior lamina resection often causes loss of spinal stability, so screw rod internal fixation technology is needed to maintain the stability of lumbar spine. Finite element analysis can be used to simulate the stress distribution of the spine and internal fixation system after spinal surgery. OBJECTIVE： To build three-dimensional finite element model of spinal L_1 to L_3, analyze the spinal stability and stress distribution after the total laminectomy and insertion of bilateral pedicle screw using finite element method.METHODS： L_1-L_3 CT data could be collected from an adult healthy male volunteer. Mimics14.01, 3-matic（V6.0） and Ansys 15.0 could be used to set up the intact lumbar spine finite element model of L_1-L_3（group A）, the L_1-L_3 finite element model after L_2 total laminectomy（group B）, and the finite element model of L_2 total laminectomy and insertion of bilateral pedicle screw（group C）. We used software to simulate flexion, extension, lateral bending and axial rotation, and three kinds of models received finite element analysis. RESULTS AND CONCLUSION：（1） Based on the maximum of Von Mises under different motion states, the maximum stress was significantly lower in group A than in group B（P〈0.05）. The maximum stress was significantly lower in group B than in group C（P〈0.05）.（2） Based on the total deformation under different motion states, the total deformation was significantly lower in group A than in group B（P〈0.05）. The total deformation was significantly lower in group C than in groups A and B（P〈0.05）.（3） After the total laminectomy, vertebral body stress increased, especially in the lamina, pedicle and joints. The range of motion of the vertebral body increased, which influenced the stability of the vertebral body. Internal fixation could decrease range of motion. Stress concentrated on the screw. Stress on the vertebral plate and pedicle decreased. The stability of vertebral body increased. Excessive stress concentrated

关 键 词：内固定器 有限元分析 生物力学 组织工程 骨科植入物 脊柱植入物 腰椎 椎板切除 椎弓根螺钉 有限元 脊柱 MIMICS 

分 类 号：R318[医药卫生—生物医学工程]