股骨头不同区域囊变对力学承载的影响  

The biomechanical influences of cystic degeneration in different locations within femoral head

作　　者：赵德伟[1] 徐达传[1] 崔旭[2] 

机构地区：[1]南方医科大学解剖教研室,广州大连大学附属中山医院510515 [2]大连大学附属中山医院

出　　处：《中华骨科杂志》2005年第4期232-235,共4页Chinese Journal of Orthopaedics

摘　　要：目的探索股骨头不同部位囊变对股骨头力学承载的影响。方法取新鲜人体股骨上段标本,行螺旋CT断层扫描,得到CT数据二维图像,采用Efilm软件系统处理,人工识别股骨头边缘轮廓,将数据输入计算机,利用Ansys-5.7大型计算机软件建立股骨上段三维有限元异物同构模型,模拟股骨头内不同部位直径1cm的囊变灶。施加3种不同载荷,分析股骨头内应力分布情况及应力/强度比值,预测股骨头塌陷的危险性。结果所构建股骨头三维有限元异物同构模型共有21852个节点,10472个单元。囊变区强度降低导致应力下传受限,在其边缘区产生应力集中。股骨头负重区下方及其内侧和外侧的囊变应力集中最明显,表现为张力集中,其上方骨板下松质骨应力/强度比值明显升高,易引起股骨头塌陷。当囊变位于股骨头的前方、后方或下方时,塌陷风险小。结论股骨头囊变灶位于股骨头负重区的下方或其内、外侧时,可行带血运的髂骨瓣植入,骨瓣应与软骨下骨板接触。如果坏死范围较大,负重区下方及其内外侧均受累,髂骨瓣应位于负重区的下方。Objective To explore the biomechanical influences of cystic degeneration in different locations on femoral head and guide the appropriated surgical treatment to preserve the femoral head. Methods First scanning a upper femur specimen with spinal CT, dealing the two-dimensional image with Efilm software, identifying the outline of the femoral head by range estimation, inputting coordinate value of the femur into the computer to build up three-dimensional finite element model of the upper femur by Ansys-5.7 software, then simulating necrosis and cystic degeneration of 1 cm diameter by analogue computer, at last putting three kinds of pressure on the femoral head respectively to analyse the stress distribution and the stress/strength ratio and predict the collapse of the femoral head. Results The tension concentration was obvious when the necrosis and cystic degeneration was beneath the loading area or medial or lateral to the loading area in the femoral head, the stress/strength ratio of the cancellous bone beneath the articular surface was high which tends to cause collapse of the femoral head. When the necrosis and cystic degeneration located in the inferior parts of the femoral head, the strain concentration was not obvious and the stress/strength ratio of the cancellous bone beneath the articular surface was normal and the femoral head had little danger of collapse. When the focus located in the anterior or posterior part of the femoral head, its upper edge displayed tension concentration but not obvious and the stress/strength ratio of the cancellous bone beneath the articular surface was lower than normal and the danger of collapse was little. Conclusion When the necrosis and cystic degeneration is beneath the loading area or medial or lateral to the loading area in the femoral head, the focus should be cleared thoroughly and the vascularised bone flap should be implanted ideally with abutment against the subchondral plate to prevent the collapse of the femoral head. If the necrotic range is large involved th

关 键 词：股骨头不同区域 囊变 力学 股骨头负重区 三维有限元 股骨头塌陷 CT断层扫描 不同部位 股骨上段 同构模型 股骨头内 应力集中 计算机软件 髂骨瓣植入 二维图像 软件系统 边缘轮廓 数据输入 分布情况 强度 边缘区 外侧 骨应力 

分 类 号：R681.8[医药卫生—骨科学]