Abstract: ObjectiveTo evaluate the effectiveness of mesenchymal stem cell (MSC) in osteonecrosis of the femoral head defect(ONFH) repair. MethodsAniaml model of ONFH defect were established with rabbits, which were divided into 3 groups,group A did not infill anything as control, nano Hydroxyapatite/collagen(nHAC) as group B,nHAC+MSC as group C.Histology change were investigated 4,8,12 weeks after operation respectively.Results groups B and C were different with group A. The difference between groups A and C was more significant. ConclusionMesenchymal stem cell has a strong activity of osteoconduction,it has a value in repairing the bone defect of ONFH and the treatment of ONFH.

Key words: osteonecrosis of the femoral head, bone defect, bone mesenchymal stem cell, rabbit