CS-ACIA Prospective Open-label Multi-center Study to Demonstrate the Safety and Efficacy of Cells Sheet-Autologous Chondrocyte Implantation（CS-ACI）for the Treatment of Articular Cartilage Defects

All procedures are carried out after obtaining informed written consent from patients. Cartilage tissue is acquired from the Non-weight-bearing area of patients. chondrocyte are isolated and grown in culture for 6-8 weeks. After this time interval, the cells are reprocessed and the cell sheet is obtained. Implantation of the chondrocyte sheet into the Cartilage defect of the keen.The patients will be assessed clinically with scoring systems preoperatively as well as 24 months postoperatively to assess relief of symptoms and joint function. Radiological assessment (MRIs)of the affected joints will be performed at the same time points aforementioned to assess integrity of the formed cartilage. Second look arthroscopy and biopsy will also be performed to histologically assess the repair tissue and grade it via arthroscopic grading system according to the International Cartilage Repair Society guidelines.