Summing up, most of reported studies are uncontrolled case series although there are a few controlled studies. Local implantation of bone marrow aspirate concentration to core decompression tract was most commonly used while some of recent studies used culture-expanded bone marrow stem cells. Scaffolding materials include fibrin glue, platelet rich plasma, β-TCP, autologous bone and tantalum rod. While it is difficult to compare individual studies because of heterogenous methods of application, bone marrow aspirate concentration or bone marrow stem cell seems to have  reasonable, if not remarkable, effects in early stage (Ficat I or II) osteonecrosis of femoral head in terms of symptomatic releief and preventing progression of femoral head collapse.