球囊扩张骨水泥填充治疗股骨头缺血坏死的有限元分析和生物力学研究

摘要

Objective To evaluate the biomechanical changes of balloon inflating and cement filling in avauscular necrosis of the femoral head using finite-element analysis. Methods The procedure of percutaneous balloon inflating and cement filling was simulated in fresh specimen of human femoral head. CT scan and three-dimensional reconstruction were used to establish the three-dimensional "model of the femoral head. The physiological load was analyzed using three-dimensional finite element model to simulate the load and calculate stress on the hip during walking. Finite element analysis was performed on the avascular necrosis model and balloon inflating and bone cement filling model to measure the Von-Mises force at the top, neck and weight-bearing area of the femoral head. Another 8 fresh specimens of femoral head necrosis of human were obtained to stimulate balloon inflating and bone cement filling procedures, and the displacement of the femoral head under different loads was recorded before and after the procedures. Results After bone cement filling in the necrosis area, the load reduced significantly in the weight-bearing area of the femoral head, and the load distribution became more uniform at the femoral neck and the top of the head. The anti-deformation ability of the necrosis femoral head increased after bone cement filling. The infinite-element analysis and specimen biomedical test showed similar results. Conclusion Percutaneous balloon inflating and bone cement filling in the necrosis area can change the biomechanics mechanism of the femoral head and neck, improve the supporting capacity under load, and prevent the progression of head collapse.%目的 采用有限元分析的方法研究球囊扩张骨水泥填充在治疗股骨头缺血性坏死中的生物力学变化,为临床应用提供理论依据.方法 在人新鲜股骨头缺血性坏死标本上,模拟经皮穿刺球囊扩张骨水泥填充操作过程,并采用螺旋CT对股骨头标本薄层扫描重建股骨头三维模型.采用有限元分析技术,模拟平地步行单髋的峰值受力情况进行加载和求解,分别对股骨头缺血性坏死模型和球囊扩张骨水泥填充的模型进行计算,对股骨头负重区、股骨颈周围区域和股骨头顶端的Von-Mises值进行计算和分析.另取新鲜人缺血性坏死股骨头标本8个,模拟球囊扩张骨水泥填充手术操作,对操作前后股骨头在不同负荷下的位移进行测量,对比标本的测试结果和有限元模拟所得的负荷-位移结果,对所建立的模型进行验证.结果 有限元分析结果显示球囊扩张骨水泥填充后,股骨头的负重区所承受应力显著降低,股骨头顶端和股骨颈的应力分布均匀.标本生物力学测试显示骨水泥填充后股骨头的承载能力增加.有限元分析结果和标本生物力学测试结果相似.结论 球囊扩张骨水泥填充股骨头坏死区域,增强了股骨头的支撑能力,能够有效抵抗股骨头塌陷,可能避免股骨头塌陷进一步进展.