Infrapatellar fat pad-derived mesenchymal stem cell therapy for knee osteoarthritis.

PURPOSE The aim of the study was to determine if isolated mesenchymal stem cells (MSCs) derived from the infrapatellar fat pad could effectively improve clinical results when percutaneously injected into arthritic knees. LEVEL OF EVIDENCE Therapeutic case-control study; Level III. METHODS Twenty five stem cell injections combined with arthroscopic debridement were administered to patients with knee OA. A mean of 1.89 × 10(6) stem cells were prepared with approximately 3.0 mL of platelet-rich plasma (PRP) and injected in the selected knees of patients in the study group. RESULTS The mean Lysholm, Tegner activity scale, and VAS scores of patients in the study group improved significantly by the last follow-up visit. No major adverse events related to the injections were observed during the treatment and follow-up periods. The results were compared between the study and control groups, in which the patients had undergone arthroscopic debridement and PRP injection without stem cells. Although the preoperative mean Lysholm, Tegner activity scale, and VAS scores of the study group were significantly poorer than those of the control group, the clinical results at the last follow-up visit were similar and not significantly different between the two groups. CONCLUSIONS The short-term results of our study are encouraging and demonstrate that infrapatellar fat pad-derived MSC therapy with intraarticular injections is safe, and provides assistance in reducing pain and improving function in patients with knee OA.