Hemorrheologic Changes in Steroid-induced Avascular Necrosis of Femoral Head After Hyperbaric Oxygen Treatment

Objective: To investigate the hemorheologic changes in different stages of in the steroid-induced avascular necrosis of femoral head after hyperbaric oxygen treatment,and to explore the pathogenesis.Methods: Sixty adult Japanese rabbits were randomly divided into two groups as model group(n=42) and blank control group(n=18).Prednisolone acetate at 10 mg/kg for twice per week was injected in each rabbit of the model group,while in the control group the normal saline was injected for six weeks.Then,rabbits in the model group were randomized into hyperbaric oxygen(HBO) group(n=16) and model control group without HBO treatment(n=16).At the end of 2,4,6,8,10,12 weeks,hemorheologic and pathological changes of femoral head in light microscope,electron nicroscope or X-ray were observed.Results: At the end of the 2nd week,4th week and 6th week,blood viscosity and plasma viscosity in model group were higher than those in control group.Osteoporosis of the femoral head,increased numbers of empty bone lacunae and fat cells,shrinked nuclei,dissolved osteocytes and fragments were observed under electron microscope in the model group.In the HBO treatment group,the above changes were less than in the model control group.Conclusion: The large dosage of hormone could cause the characters of hemorrheology get worse,which may be the cause of avascular necrosis of femoral head.