Hormone Correlation Osteonecrosis Animal Model Experimental Study

Objective:To produce animal model of Steroid-induced femoral head necrosis which structure is more similar to the human body,s.Methods:Thirty 4-month-old rabbits, to maintain their both lower extremities weight-bearing, were randomly divided into experimental and control groups .It is injected Prednisolone acetate into the gluteal muscle in the doses of 12.75mg/kg, simultaneously ,injected in Penicillin-na G 100,000 u per one rabbit, 2 times per week in the experimental group. It is injected the same dose of Saline&Penicillin-na into the gluteal muscle in the control group.After making X-radiographic examination in 4,6,8 weeks ,two group rabbits are executed. selected as the experimental rabbit femoral head specimens of femoral head necrosis of tissue biopsies in order to understand the situation.Results:①X -ray examination: After 6,8 weeks the density of the femoral head is heterogeneous,where is a cystic translucent zones under the articular surface,but the shape of the femoral head was well in the test group. The density of the femoral head is uniform, osseous substance is no abnormal in control group.②Light microscopy observation: Trabecular bone in the subchondral area is thinning, which structure is disorder or fracture in the test group. The number of fat cell nucleus and empty lacunae increased significantly. These are significant differences in comparison with the control group.③Electron microscope: After 6 weeks the number of bone cells is reduced significantly, which structure is ambiguous. And the nucleus is pyknotic,some of those is out-of-center. The volume of the fat cells in the bone marrow tissue is enlarge, the number is increase in the experimental group; however, the surface of the bone cells are coveraged with the osteoblast. The number of the polyribosome is large and Mitochondrial structure is developed. Bone cells scattered is in the stroma, and its nucleolus is clearly visible.Conclusion: It is was proved to be successful that the animal model of femoral head necrosis (FicatⅡperiod) is induced through the maintenance of the rabbit lower extremity weight-bearing and injection hormones in large doses.