Clinical Study of Intra Articular Injection of Catholic MASTER Cell (Bone Marrow Derived Mesenchymal Stem Cell) in Knee Osteoarthritis

1. objective \- safety and efficacy evalaution of MASTER cells injected into knee of patients with osteoarthritis 2. background * osteoarthritis * Osteoarthritis is severe and intractable musculoskeletal disease that eventually leads to joint failure and pain due to inflammation and joint injury. * OA is one of the most prevalent diseases. The prevalence increases with age, but overuse and trauma can result in OA in young population as well. * Injured cartilage can not be regenerated spontaneously, untreated injured cartilage eventually leads to osteoarthritis. Surgical treatment may repair the damage but the reparied cartilage may turn out to be fibrocartilage rather than hyaline cartilage. * Curent treatment * medical therapy: medication for symptom relief, together with exercise. Medications include NSAIDS visco-supplement. * surgical therapy: total knee replacement arthroplasty * to overcome such limitations, cell therapy such as stem cell/ chondrocyte injection is being investigated 3. Hypothesis \- Intra articular injection of MASTER cells will show safety and efficacy in terms of pain and functional improvement. 4. Protocol 1) deisgn : Injection of MASTER cell 1X 10\^8 cells/2cc (experimental arm) or 2cc saline (placebo arm) into knee of patients with osteoarthritis 2) outcomes * primary outcome : safety evaluation(adverse event) * secondary outcomes : check on 1,2,3,6,9,12 months, atient reported outcome (WOMAC, KOOS, IKDC, pain VAS) 3,12 months SF-36, knee MRI score, serum cytokine, bone turnover marker 12 months x-ray 3) Disease * osteoarthritis 4\) Subjects 1. inclusion : age 20-80yrs, diagnosed with OA according to ACR criteria for knee OA, baseline pain VAS equal or more than 50mm 2. exclusion: lower extremities surgery within 6months or planned surgery, concommitant systemic rheumatic diseases that can affect the results of the trial, steroid intraarticular inejction into the inde