In summary, because of challenging nature of constructing a viable cell-scaffold composite, clinical application of stem cell is still in its incipient stage. Sporadic reports describe the application of mesenchymal stem cells from bone marrow or adipose tissue along with various scaffolding materials to treat long bone defects. While complete regeneration of bone in the large defects was demonstrated  in those reports, it is still premature to draw conclusion on their safety and efficacy with the absence of controlled trials.