Shinya Miki, Masato Takao, Wataru Miyamoto, Takashi Matsushita and Hirotaka Kawano
Objective: 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.
Methods: Forty-eight knees of 24 beagle dogs were randomly assigned to 16 groups (n=3) according to both the number of injected SMSCs (0.5×105 cells, 5×106 cells, 5×107 cells) 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.
Results: The mean ICRS visual assessment scale and the mean modified O’Driscoll histological score were 1.0 ± 0.00 and 11.0 ± 0.00 in the control group. On the other hand, the mean ICRS visual assessment scale and the mean modified O’Driscoll histological score were 7.3 ± 3.21 and 30.7 ± 7.23 in the group injected with 5×106 cells and 0.01% HA.
Conclusion:Intra-articular injection of SMSCs with HA may be effective for stimulating articular cartilage repair. Our results suggest that there is an ideal combination of the number of SMSCs and the concentration of HA for promoting particular cartilage repair.