The purpose of this study was to evaluate effectiveness of intra-articular injection of synovium-derived mesenchymal stem cells (SMSCs) and hyaluronic acid (HA) for the treatment of articular cartilage defects in a canine model.
Forty-eight knees of 24 beagle dogs were randomly assigned to 16 groups (n=3) according to both the number of injected SMSCs (0.5×—105cells, 5×—106cells, 5×—107cells) and the concentration of HA (0%, 0.01%, 0.1%, 0.5%). A partial-thickness cartilage defect was created in the medial femoral condyle under arthroscopy. After seven weeks, autologous SMSCs with or without 1 ml HA were percutaneously injected into the injured knee. In the control group, 1 ml saline was injected. Twelve weeks after the injection, evaluation was performed using the International Cartilage Repair Society (ICRS) visual assessment scale and the modified O\'Driscoll histological score.