实验性股骨头骨缺损修复过程的生物力学研究

目的　对股骨头内骨缺损自然修复过程进行分析、评价。方法　本实验分脱位组、未脱位组及正常组 ,对犬股骨头内骨缺损修复过程进行计量组织学及生物力学研究。结果　脱位组股骨头均塌陷 ,未脱位组囊腔硬化带形成 ,两组囊腔均未完全闭合。脱位组的骨小梁体积及软骨下骨厚度、软骨下骨生物力学特性均较正常组及未脱位组低。脱位组松质骨的抗压强度及弹性模量较未脱位组低。结论　股骨头脱位可致股骨头坏死塌陷 ,股骨头塌陷与软骨下骨的生物力学特性及厚度有关 ,后两者间亦存相关关系。囊腔硬化带形成是一种代偿反应 ,但可产生应力遮挡 ,不利于囊腔闭合。

A biomechanical study on the restoration of experimental bone defect of the femoral head

Objective To study the restoration of bone defect of the femoral head. Methods In this experiment, these dogs were divided into 3 groups: dislocated group, nondislocated group and normal control. The histological, biomechanical changes during the of bone defect of femoral head were studied.Results In dislocated group, all the femoral head collapsed. In nondislocated group, cystic sclerous zone was formed. The cystic cavities were partially remained in both groups. Trabecular bone volume and thickness of subchondral bone in dislocated group were lower than that of nondislocated group. The maximum stress and modulus of elasticity of chancellor's bone of dislocated group was lower than that of nondislocated group, which was the highest of all groups.Biomechanical properties of subchondral bone of dislocated group were lower than that of normal group and nondislocated group.Conclusion Osteonecrosis and collapse of the femoral head can be caused by dislocation of the hip. The collapse of femoral head is tightly related to the biomechanical properties and thickness of the subchondral bone. There also is a positive correlation between the later two. The cystic sclerous zone is a compensative reaction, but it can produce stress-shelfing effect, so it is a disadvantage for the closing of bone defect. This model can be used in the study of the effectiveness of implantation in the repair of femoral head necrosis