脊柱Denis B型骨折行单节段与双节段融合后生物力学强度比较  

Comparison of biomechanical properties of single-segment and two-segment fusion for Denis type B spinal fracture

作　　者：苏云山[1] 任栋[1] 王鹏程[1] 

机构地区：[1]河北医科大学第三医院骨科创伤急救中心河北省骨科生物力学重点实验室,石家庄050051

出　　处：《中华骨科杂志》2013年第7期748-754,共7页Chinese Journal of Orthopaedics

摘　　要：目的比较脊柱DenisB型骨折行单节段与双节段融合后的生物力学强度。方法选取因脊柱DenisB型骨折而行后路复位椎弓根螺钉固定阜前路双节段融合和行前路单节段融合患者各1例，两例均为L1椎体爆裂性骨折的女性患者，年龄为45岁和41岁，Frankel分级分别为B级和C级。术后1年患者均达到影像学椎间融合标准。收集2例患者术后1年随访时的CT数据，包括行单节段融合患者取及未取椎弓根螺钉的CT数据，行双节段融合患者未取出螺钉的CT数据；将此三组数据导入Mimics软件建立T11-L2三维模型。建模后，将模型再次导入到有限元分析软件ANSYS，设定边界条件并施以260N的轴向压力及10Nm扭矩，模拟椎体前屈、后伸、左侧弯、右侧弯、左旋、右旋运动，观察三个模型在上述六个运动方向上的脊柱运动平均位移以及椎间融合后T11-12椎间盘的应力分布云图，并比较椎间盘的平均VonMises应力。结果双节段融合与单节段融合未取内固定组脊柱活动平均位移比较，差异无统计学意义。单节段融合取内固定组在上述六个运动方向上均明显高于双节段融合和单节段融合未取内固定组。在上述六个运动方向T11-12椎间盘平均VonMises应力，双节段融合大于单节段融合取和未取内固定组，单节段融合未取内固定组大于取内固定组。结论单节段融合手术在椎问融合满意的前提下，取出后路椎弓根螺钉可提高脊柱活动度，减少椎间盘应力，延缓椎间盘退变。Objective To compare the biomechanical properties of single-segment and two-segment fusion for Denis type B spinal fracture. Methods Two female patients with Denis type B L1 vertebral fracture were enrolled in this study. The 45-year-old patient （Frankel B） underwent posterior reduction and fixation with pediele screw system plus anterior two-segment fusion and the 41-year-old patient （Frankel C） un- derwent posterior reduction and fixation with pedicle screw system plus anterior one-segment fusion. The in- tervertebral fusion was achieved in both patients 1 year alter operation. CT data of the two patients at 1 year after surgery was collected, including data of 41-year-old patient before and after removal of pedicle screws and data of 45-year-old patient without removal of pcdicle screws. These three sets of data were imported into the Mimics software to establish T11-L2 three dimensional models. After construction of the models, they were imported into ANSYS software. An axial load （260 N） and 10 Nm torque were loaded to simulate the flexion, extension, lateral bending and rotation of the spine, respectively. Meantime, under above 6 kinds of motion form, the average displacement of the spine and the average Von Mises stress of T1H2 intervertebral disc were recorded and compared. Results There was no significant difference in the average displacement of the spine between two-segment fusion patient and single-segment fusion patient without removal of pedicle screws. However, under all motion forms, the average displacement of the spine of single-segment fusion pa- tient after removal of pedicle screws was significantly higher than that before removal of pedicle screws and that of two-segment fusion patient. The average Von Mises stress of T11-12 intervertebral discs of two-segment fusion patient was significantly higher than that of one-segment fusion patient. Moreover, the average Von Mises stress of T11-12 intervertebral discs of single-segment fusion patient before removal of pedicle screw was hig

关 键 词：脊柱骨折 脊柱融合术 生物力学 

分 类 号：R687.3[医药卫生—骨科学]