We observed 21 prominent protein spots that differed between the two groups. Three of these proteins were upregulated and the rest 18 proteins were downregulated in patients with steroid-induced ONFH. The spots determined in the steroid-induced ONFH and health control groups were replicable.The spot no. 21 corresponding to an upregulated protein in patients with steroid-induced ONFH was identified as SAA.