Of bone regeneration, osteonecrosis of femoral head  has been the greatest focus for cell therapy . However, most reported studies were uncontrolled and used bone marrow aspirate concentrate. Prospective controlled studies using mesenchymal stem cells have recently been reported. More evidence will be accumulated to prove the effectiveness of  stem cell treatment in arresting the progression  of the disease. Large long-bone defect is the entity where regenerative medicine is most needed. Because of challenging nature of constructing a viable cell-scaffold composite,, clinical application of stem cells is still in its incipient stage