Knee osteoarthritis is the most common form of arthritis. Treatments involve high costs in terms of social and economic, are palliative and do not contemplate healing by regenerative therapy. It has been shown recently, that mesenchymal stem cells (MSC) can be expanded in vitro and may regenerate several damaged or injured tissues. In addition its has demonstrated that MSC are able to modulate immune responses and to control inflammation through its action on T lymphocytes. Preliminary studies in animal models, including one carried out in an equine by the investigators research group, confirms feasibility, safety and efficacy evidence proposed treatment protocol.This study is designed to evaluate therapeutic potential and safety of mesenchymal stem cells in improvement of osteoarthritis clinical manifestations.This study is designed to evaluate therapeutic potential and safety of mesenchymal stem cells in improvement of osteoarthritis clinical manifestations.