Abstract:

BACKGROUND: Studies demonstrated that pravastatin can promote the repair of steroid-induced avascular necrosis of femoral head (SANFH) via up-regulating expressions of endogenous bone morphogenetic protein 2, core-binding factor α1 and vascular endothelial growth factor.
OBJECTIVE: To verify the ultra-structural changes of SANFH animal models after intervened by pravastatin.
METHODS: Totally 80 New Zealand white rabbits were randomly divided into a normal control group (n = 18) and experimental group (n = 62). Rabbits in the experimental group were prepared for SANFH models. At 5 weeks after model preparation, 36 rabbits in the model group were assigned into the model and pravastatin groups, with 18 animals in each group. Rabbits in the pravastatin group received intragastric administration with 1.2 mg/kg pravastatin, once per day, and the same volume of distilled water was given to those in the model and control groups. The femoral head specimens were observed under a transmission electron microscope at 8, 12 and 16 weeks after model preparation.
RESULTS AND CONCLUSION: Transmission electron microscopy showed that severe degeneration and necrosis could be found in the model group, most of osteocytes disappeared in the lacunae, and there were more fat deposition in the remnant osteocytes. Compared with the model group, the damage of osteocytes in the pravastatin group were slighter, the morphology of cells were normal with few fat deposition. The results demonstrated that pravastatin can effectively restore femoral head necrosis of rabbits of SANFH animal models in the early stage.