Empirical Study Of The Influence Of Sodium Pravastatin On The Number Of Osteoclast During Osteonecrosis Of Femoral Head Of Rabbits

Objective:To investigate the influence the number of osteoclast during model of steroid-induced avascular necrosis of femoral head(SANFH) of rabbits which are injected sodium pravastatin, we can more effectively prevent and therapy the SANFH in clinical orthopedics.Methods:(1)40 healthy rabbits were randomly divided into three groups:the control group (A group),the experimental group (B group) and the therapy group(C group), with 12 rabbits in A,with 14 rabbits in B and C groups. During 8 weeks,the A group were injected respectively with normal saline (in dosages of 0.32mg/kg per time) in the bilateral gluteus maximus muscle twice per week.B and C groups were injected respectively with prednisolone acetate (7.5mg/kg per time) in the gluteus maximus muscle twice per week for 8 weeks.In addition, C group was irrigation stomach with sodium pravastatin 20mg/times in the gluteus maximus muscle at the same time. (2) Utilize the X ray,spiral computerized tomography (CT) and single photon emission computed tomography(SPECT) to confirm the accurate time of animal model of steroid-induced avascular necrosis of femoral head(SANFH).(3) To culture osteoclasts in vitro with Chambers'method, tissue sections were stained with tartrate-resistant acid phosphatase (TRAP) histochemistry to analyze the changes of the amount and distribution of osteoclasts on the femoral head.Results:(1) At eighth weeks,40 healthy rabbits are 36 survived(A group none dead,B group 3 dead and C group 1 dead).In both B and C groups,there are 21 rabbits which appeared deformities of bilateral femoral heads,and the achievement ratio model are approximately 87.5%.(2)To compare with the A group,the number of osteoclasts appearing in the B group was increased markedly. There were statistically significant differences in the amount of osteoclast between A and B group(p<0.05).(3) The number of osteoclasts appearing in the C group was less than the B group,and there were statistically significant differences in the amount of osteoclast between B and C group(p<0.05).(4) There were no statistically significant differences in the amount of between A and C group(P>0.05).Conclusion:(1)Prednisolone acetate could lead to steroid-induced avascular necrosis of femoral head.(2) Sodium pravastatin could partially prevent the osteoclasts in vitro.