股骨头缺血性坏死股骨头塌陷的预测

Predicting the collapse of the femoral head in avascular necrosis

目的 :采用三维有限元力学分析方法 ,计算出以股骨头中心为顶点可能出现塌陷的临界坏死区域角度。对股骨头骨坏死塌陷进行定量的预测。方法 :对因股骨头骨坏死而行全髋关节置换术切除的共 2 2个外形完整股骨头作为观察对象 ,进行大体及组织学测量观察。设计出正常股骨头力学模型和股骨头骨坏死力学模型 ,采用三维有限元力学分析方法分别计算股骨头的压应力、压应变的分布 ,计算出股骨头可能出现塌陷的临界坏死区域角度。结果 :股骨头塌陷均位于负重区 ,呈不规则圆形 ,切面上坏死区分为 6层。三维有限元力学分析显示以股骨头中心为顶点坏死区 >110°时 ,股骨头内坏死区的压应变大于软骨下骨板的应变能力 ,出现软骨下骨板骨折。结论 :股骨头冠状面MRI显示坏死区域最大范围以股骨头中心为顶点 ,底为承重区 ,夹角 >

Objective:To predict the necrosis and depression of the femoral head through measurement of the critical necrotic angle.Methods:22 femoral heads collected from hip joint replacement were undergone mophologic histologic observation and three dimension finite element analysis of the compress stress and strain distribution.Results:Morphologic and histologic observation showed the collapse of femoral heads occurred in weight bearing area of the head with an irregular round shape,six strata could be seen in the section of the heads.With the center of the femoral head as top,when the angle is more than 110°,subchondral plate in the weight bearing region may fracture. Conclusion:When the angle of AVN,with the center of the head as top,is more than 110°,the femoral heads have a high collapsing risk.