RESUMEN
<p><b>OBJECTIVE</b>To investigate the effect of two treating principles and formulas, which are named 'invigorating spleen to remove phlem and promoting blood circulation to remove meridian obstruction' (Jianpi) and 'invigorate the kidney and promoting blood circulation to remove meridian obstruction' (Bushen), on the expression of osteogenic factors in steroid-induced osteonecrosis of the femoral head (SONFH), such as bone morphogenetic protein 2 (BMP2) and transforming growth factor beta1 (TGFbeta1) and Smads, as well as to explore and compare their mechanisms of prevention and treatment of SONFH.</p><p><b>METHOD</b>Animal model of SONFH was established by injection with methylprednisolone in chest muscle on chickens. 48 SONFH chickens were randomly assigned to model, Jianpi and Bushen group. Another 16 normal chickens served as control group. At the 8th and 16th week, the expression of BMP2, TGFbeta1, Smad4 and Smad7 of bilateral femoral heads were detected with immunohistochemistry.</p><p><b>RESULT</b>The expression of BMP2, TGFbeta1 and Smad4 decreased, and Smad7 increased significantly in model group compared with control group. The expression of BMP2, TGFbeta1, Smad4 increased and Smad7 decreased significantly in Jianpi group at the 8th week compared with model group, and the same changes in Bushen group at the 16th week.</p><p><b>CONCLUSION</b>Both Jianpi and Bushen formulas exerted preventive and therapeutic activity on SONFH through regulating the expression of BMP2, TGFbeta1, Smad4 and Smad7 to promote bone repair. Notably Jianpi formula took effect earlier than Bushen formula</p>