椎体成形术治疗老年骨质疏松椎体压缩骨折对邻近节段生物力学的影响  

The biomechanical effects of kyphoplasty for the management of osteoporotic vertebral fractures on adjacent segments

作　　者：李志远[1] 申勇[1] 王林峰[1] 曹俊明[1] 徐佳欣[1] 武刚[1] 

机构地区：[1]河北医科大学第三医院脊柱外科,石家庄市050051

出　　处：《中国脊柱脊髓杂志》2009年第5期388-391,共4页Chinese Journal of Spine and Spinal Cord

基　　金：河北省自然科学基金(编号:C2007000870)

摘　　要：目的:应用三维有限元模型探讨椎体成形术治疗老年骨质疏松椎体压缩性骨折对邻近节段生物力学的影响。方法:选取1例老年骨质疏松椎体(T12)压缩性骨折女性患者的术前、球囊扩张后凸成形术(KP)术后CT片,范围为T11～L1(包括病椎、邻近椎体和邻近椎间盘),分别建立术前、术后的三维脊柱功能单元的有限元模型。对T11上终板垂直向下加载300N的力矩和10N·m的旋转力矩,分析在垂直载荷、前屈、后伸、侧屈及旋转的情况下,手术前后病变椎体的变化以及椎体皮质骨、松质骨、相邻椎间盘、终板的应力改变情况。结果:成功建立术前、术后脊柱功能单元的三维有限元模型,术前T12椎体前、中缘高度分别为13.1mm和10.9mm,术后分别为15.2mm和12.6mm,明显增高(P<0.05)。在垂直载荷应力下,邻近椎体上下终板(T11下终板和L1上终板)所受应力无显著变化,但在前屈、后伸、侧屈、轴向旋转时T11/12椎间盘所受压力分别增加0.66、0.88、2.25、0.85MPa;T12/L1椎间盘所受压力分别增加1.56、1.60、0.50、2.35MPa,与术前比较均有显著性差异(P<0.05)。结论:球囊扩张后凸成形术有效改善了脊柱功能单位的生物力学性能,并未对邻近椎体产生较大的影响,但可能会加速邻近椎间盘的退变。Objective：To investigate the biomechanical effects of kyphoplasty for the management of vertebral osteoporotie fractures on adjacent segments by three-dimensional（3-D） finite element analysis.Method：Two finite element models of T11-L1 were established using CT scan taken from a female patient undergoing kyphoplasty treatment,objects investigated included fractured vertebral body （T12）,adjacent nontreated bodies （T11 ,L1） as well as adjacent intervertebral discs.The three-dimensional finite element models with respect to FSU at pre and post-operation were established respectively.Simulations were conducted when imposing a vertical compression preload of 300N and torsion preload of 10N·m at T11 upper end plate,the stress protocol in adjacent intervertebral dises,endplate,eancellous bone,cortical bone as well as fractured and adjacent vertebral bodies following kyphoplasty were quantified under flexion/extension,lateral bending and axial rotation respectively.Result：A validated T11-L1 finite element model of two-functional spinal unit（FSU） undergoing a simulated kyphoplasty augmentation in T12 was established.Preoperatively,the anterior and midline height of vertebral body were 13.1mm and 10.9mm respectively,while those parameters at postoperation were 15.2mm and 12.6mm respectively,which showed significant difference between pre and post operation （P〈0.05）.Under vertical preload,the stress in end-plate at adjacent segment showed no change,while under condition of extension-flexion,lateral bending and axial rotation,the increased stress in T11/T12 disc were 0.66,0.88,2.25, 0.85MPa,the increased stress in T12/L1 disc were 1.56,1.60,0.50,2.35MPa,which showed significant difference between pre and post operation （P〈0.05）.Conclusion：Kyphoplasty can effectively restore the biomechanical features of fractured vertebral body,however this may play a critical impact on adjacent segments and ac-celerate the degenerative process.

关 键 词：椎体骨折 骨质疏松 后凸成形术 生物力学 有限元分析 骨水泥 

分 类 号：R318.01[医药卫生—生物医学工程] R683.2[医药卫生—基础医学]