椎体后凸成形术后骨水泥椎间盘渗漏对邻近节段力学影响的有限元分析

目的 探索椎体后凸成形术(PKP)术后骨水泥椎间盘渗漏对相邻椎体的力学影响,探讨相邻椎体继发骨折的病因.方法 利用MIMICS软件用有限元方法对1例T12压缩骨折PKP术后出现椎间盘骨水泥渗漏的患者手术前后CT图片进行预处理,后导入ABAQUS软件中建立T10-L2的三维有限元模型,设置0.3、1.0、4.0 Mpa 3种轴向载荷进行生物力学分析,观察不同载荷下模型整体及各部分的Von Mises应力,重点评价骨水泥椎间盘渗漏对骨折相邻椎体的力学影响.结果 成功建立了PKP术后骨水泥椎间盘渗漏的手术前后三维有限元模型,当轴向压力以0.3、1.0、4.0 MPa增加后,椎间盘、软骨终板和椎体整体的应力也成比例增加.PKP术后脊柱胸腰段各部位的应力开始重新分布,增强椎体(T12)的上、下终板应力增强区域范围增加;相邻椎间盘(T11-12、T12-L1)及相邻终板(T11下终板、L1上终板)的应力增强区域增加;T12相邻椎体(T11、L1)所受最大应力显著增加,但是远端椎体(T10、L2)的最大应力明显减少.结论 PKP术后骨水泥椎间盘渗漏引起上下相邻椎体继发骨折的并发症可能和生物力学行为的改变密切相关.

Abstract：

Objective To explore the biomechanical effects on adjacent vertebra of thoracolumbar osteoporotic vertebral compression fracture (OVCF) after percutaneous kyphoplasty (PKP) with cement leakage into the disc by using finite element analysis. Methods T10-L2 segment data were obtained from computed tomography (CT) scans of an elder female with single T12 OVCF undergoing a cement leakage into the T1 2-L1 disc after PKP. A three-dimensional finite element Model of thoracolumbar spine (T10-L2)was built in the Mimics and the ABAQUS software. The stress on annulus fiber, nucleus pulposus, endplate and facet joints under axial pressure (0. 3, 1.0, 4. 0 MPa) were analyzed. Results The 3D finite element after percutancous kyphoplasty (PKP) with cement leakage into the disc may be strongly related with the changes of biomechanical effects on adjacent vertebras of thoracolumbar OVCF. Models of thoracolumbar OVCF before and after PVP with a cement leakage into the T12-L1 disc were successfully established. The stresses increased with a rising axial pressure in the model of cement leakage into the disc after PVP, the stress augmentation scope on adjacent end plates ( T11 low plate & L1 top plate) and intervertebral disc (T11-12 & T12-L1 ) increased. The maximal Von Mises stress on adjacent vertebras (T11 & L1 ) increased while but the maximal Von Mises stress on end vertebras (T10 & L2) decreased. Conclusion Postoperative adjacent vertebral fracture.

Biomechanical effect on adjacent vertebra after percutaneous kyphoplasty with cement leakage into disc: a finite element analysis of thoracolumbar osteoporotic vertebral compression fracture

Objective To explore the biomechanical effects on adjacent vertebra of thoracolumbar osteoporotic vertebral compression fracture (OVCF) after percutaneous kyphoplasty (PKP) with cement leakage into the disc by using finite element analysis. Methods T10-L2 segment data were obtained from computed tomography (CT) scans of an elder female with single T12 OVCF undergoing a cement leakage into the T1 2-L1 disc after PKP. A three-dimensional finite element Model of thoracolumbar spine (T10-L2)was built in the Mimics and the ABAQUS software. The stress on annulus fiber, nucleus pulposus, endplate and facet joints under axial pressure (0. 3, 1.0, 4. 0 MPa) were analyzed. Results The 3D finite element after percutancous kyphoplasty (PKP) with cement leakage into the disc may be strongly related with the changes of biomechanical effects on adjacent vertebras of thoracolumbar OVCF. Models of thoracolumbar OVCF before and after PVP with a cement leakage into the T12-L1 disc were successfully established. The stresses increased with a rising axial pressure in the model of cement leakage into the disc after PVP, the stress augmentation scope on adjacent end plates ( T11 low plate & L1 top plate) and intervertebral disc (T11-12 & T12-L1 ) increased. The maximal Von Mises stress on adjacent vertebras (T11 & L1 ) increased while but the maximal Von Mises stress on end vertebras (T10 & L2) decreased. Conclusion Postoperative adjacent vertebral fracture.