Experimental investigation of the pathological changes in subchondral cocortical bone in steroid-induced osteonecrosis / 中国矫形外科杂志

ABSTRACT

[Objective]To investigate the morphological changes that take place in the subchondral cocortical bone in steroid-induced osteonecrosis and analyze the reasons leading to humeral head collapse in juvenile rabbits.[Method]Five-six month-old female rabbits were separated by two groups.A modified version of the methods was used to replicate steroid enhanced osteonecrosis anminal humeral head models with Shwartzman reaction in group A,and group B served as the single control.Each humeral head was obtained 10 weeks after the drugs injection.Subchondral cortical bone was observed,and the number of haversian canals was counted.The microcirculatory changes were also detected with scanning electron microscope.[Result]In group A,the Haversian canals in' subchondral area almost disappeared;the subchondral cortical bone disappeared with its arch,dome and bridge structures.Microcirculatory stasis happened in the subchondral vessels.Some humeral heads collapse were observed.While in group B,subchondral cortical bone is integrity and continuity,forming arch,dome and brige structures with subtrabecular bone.[Conclusion]The disappearance of the subchondral cortical bone is a major reason leading humeral head collapse,and ischemia is the critical reason of it.