实验性股骨头骨缺损修复过程的生物力学研究

目的及方法　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的研究。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 ,未脱位组在三组中最高。脱位组的软骨下骨的生物力学特性较正常组及未脱位组低。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 ,后两者间亦存在相关关系。囊腔硬化带形成是种代偿反应 ,但可产生应力遮挡 ,不利于囊腔的闭合。此模型 ,可用于研究移植等对股骨头坏死修复的效果。

A Biomechanical Study in the Repairing Process of Experimental Bone Defect of the Femoral Head

Objective To study the histological and biomechanical changes during the repairing process of bone defect of the femoral head.Methods In this experiment,the dogs were devided into three groups:dislocated group,nondislocated group and normal group.The histological,biomechanical changes during the repairing process 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 partially remained in the both groups.Trabecular bone volume and thickness of subchondral bone of dislocated group were lower than that of nondislocated group.The maximum stress and modulus of elasticity of cancellous 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-shielding 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.