Experimental Study Of Effect Of PMMA Injection On The Avascular Necrosis Of Femoral Head In Rabbit

Objective:Glucocorticoids were used to establish the animal model of avascular necrosis of femoral head in rabbit. Then, PMMA was injected into the bone marrow cavity of femoral head. Histopathological and immunohistochemical methods were used to evaluate the effect of PMMA in the process of avascular necrosis of femoral head.Method:24rabbits were randomly divided into three groups (8rabbits for each group):the control group(group A), the model group(group B), and the treatment group(group C). Glucocorticoids injection was done for group B and C for eight to ten weeks in order to establish the animal model of avascular necrosis of femoral head. Group C was injected physiological saline in the same way. From the10th to the14th week, group C was injected PMMA into femoral head. At the end of the14th week, serology detection was conducted, and all the rabbits were executed. Finally, histopathology detection and immunohisto-chemistry observation were carried out separately.Result:1. Rabbits in group B lost its weight and appeared gait abnormal in general observation.2. Rabbits in model group (group B) had a positive change in X-ray and pathology.3. the level of VEGF, TGF-(3, IL-6in model group and treatment group were higher than that of the control group, which had statistical significance. There was no significant difference between model group and treatment group.4. compared with the control group, the expression of VEGF in bone tissue in model group decreased, whereas the level in treatment group was higher than that in the model group and control group and there was statistical significance in this difference. But there was no significant statistical difference in the expression of TGF-P between model group and control group, whereas the level in the treatment group was higher than that in model group and control group. There was statistical significance in this difference.Conclusion:1. Short—term use of high-dose hormone can cause avascular necrosis of femoral head.2. VEGF, TGF, IL have closely relationship with avascular necrosis of femoral head in the development and repairing process.3. The injection of PMMA in bone marrow cavity of femoral head can effectively increase the effect of anti-pressure load and prevent subside fracture.4. There is intense expression of TGF-β、VEGF in surrounding bone tissue after the injection of PMMA.5. Irreversible damage to the surrounding bone tissues after Injection of PMMA is not observed.