An Experimental Study On Treatment Of Steroid-associated Femoral Head Necrosis In Rabbit With Theaflavin And BMSCs Transplantation

Objective: To approach the possibility of combination of theaflavin and BMSCs transplantation for steroid-associated osteonecrosis of femoral head.Methods: Animal femoral head neorosis model was made by freezing method with liquid nitrogen .24 Newzland rabbits were divided into four groups randomly,group A: no treatment; group B: only decompression; group C: decompression and BMSCs transplantation; and group D: theaflavin drench (250 mg) decompression and BMSCs transplantation. The general information of animals were recorded; after 4 and 8 weeks of operation, 3 rabbits of each group were chosen randomly to do MRI scan, and femoral heads were harvested to do histopathology and scanning electron microscope examination.Results: After 8 weeks, rabbits became more active than before treatment, and walking way became normal gradually in groups C and D . Four weeks after operation, the MRI low signal region of all groups had no obvious changes, but 8 weeks later, the necrosis signal region of group A magnified while it reduced obviously in group D. Histopathological observation: 4 weeks after operation, diffuse presence of empty lacunae were found in group A; lots of empty lacunae could been found in group B; and large amounts of osteoblats were found around the necrosis regions in groups C and D. The positive ratio of empty lacunae in group D showing significant difference compared with other groups (P < 0.05). After 8 weeks of treatment, the bone trabecula collapsed in many regions in group A; there was fibra callus formation along the decompression channel in group B; few empty lacunae was in the bone trabecular, but the shape of marrow cavity was not normal in group C; and it showed almost normal appearance in group D. The positive ratio of empty lacunae showing significant differences compared with other groups (P < 0.05). Scanning electron microscope: 8 weeks after operation, the bone trabecula collapsed in many regions, and few osteoblasts could be found on the surface, a great quantity of fat cells cumulated in the bone marrow in group A; cracked bone trabecula could be found occasionally in group B; the density of bone trabecula was lower than the normal in group C; and the shape of the marrow cavity and the density of bone trabecula were similar to the normal in group D.Conclusion: Theaflavin can promote the differentiation of osteocyte from BMSCs, the combination of theaflavin and marrow stem cells transplantation for the treatment of steroid- associated osteonecrosis of femoral head have good application prospects.