The mesenchymal stem cells after being injected into degenerated joints could differentiate into cartilage cells to make new cells and repair the injured joints. Objectives: To initially evaluate the efficacy and safety of adipose-tissue-derived stem cell therapy in primary knee osteoarthritis treatment. Methods: There are 19 patients with 38 injured joints in grade II and III according to Kellgren and Lawrence classification. Longitudinal invasive study. The protocol is intra-articular injection of autologous adipose-tissue-derived stem cell (separated from abdominal adipose tissue, activated by Adistem technology) in combination with platelet-rich plasma and hyaluronic acid to be bracket at only one time. 19 patients in this study (38 joints) were evaluated in clinical results and were assessed the thickness of the joint cartilage by ultrasound after 6 months. Results: After 6 months, the mean VAS score of 19 patients decreased from 6.7 +/- 0.8 to 2.9 +/- 1.1
WOMAC score decreased from 43.2 +/- 9.2 to 16.6 +/- 9.5, LEQUESNE score decreased from 15.8 +/- 2.9 to 7.9 +/- 2.6. The average thickness of the knee joint cartilage on ultrasound after 6 months has improved from 1.98 +/- 0.4 mm to 2.36 : +/- 0.3 mm. The proportion of knee effusion has decreased from 81.6 percent to 32. 1 percent. The therapy is relatively safe: 3 patients (15.8 percent) had increasing pain in knee after injection within 24 hours. No case had infection or bleeding at the site of injection or adipose tissue derivation. Conclusion: The autologous adipose-tissue-derived stem cell therapy initially shows clinical improvement and degenerated knee joint repairment. The therapy is safe.