Sclerotin loss after ONFH is closely related to an unbalance in osteoclast activity and differentiation. Osteoprotegerin can inhibit bone absorption of mature osteoblasts and induce apoptosis of osteoblasts. Osteoprotegerin and its ligand system have been confirmed as key factors regulating osteoblast formation and differentiation, while bone absorption plays an important role in the pathogenesis and treatment of osteoporosis, osteoarthritis and bone tumors.