The purpose of this study is to assess the safety and efficacy of implanting bead-type autologous chondrocyte (CartiLife®) obtained by culturing expanded costal chondrocytes of the patient with a chondral defect in the knee. The patients will be assessed clinically using MRI, clinical, biochemical and International Knee Documentation Committee(IKDC) outcomes preoperatively as well as 8, 24 and 48 weeks postoperatively to assess the relief of symptoms and joint function.

Inclusion Criteria:

• Adult men and women aged between 19 and 65
• Defect size: 2 to 10 ㎠ on the unilateral knee cartilage (up to 4 ㎤ in volume)
• Defect: isolated International Cartilage Repair Society(ICRS) Grade III or IV single defect chondral lesion on articular cartilage
• The joint space is maintained over 50% relative to baseline
• Patients that are able to walk without aid
• Patients that agree to abide by strict rehabilitation protocols and follow-up programs
• Patients who provide written consent to the participation of the clinical trial

Exclusion Criteria:

• Patients with inflammatory articular diseases such as rheumatoid arthritis or gouty arthritis
• Kellgren and Lawrence grade ≥ 3
• Patients with arthritis associated with autoimmune diseases
• Patients hypersensitive to bovine protein
• Patients with Haemophilia or markedly reduced immune function
• Patients hypersensitive to antibiotics like gentamicin
• Patients with arterial bleeding and severe venous bleeding
• Patients with other diseases including tumors except for cartilaginous defects of joints
• Patients with a history of radiation treatment and chemotherapy within the past two years
• Patients who are pregnant, nursing a baby or likely to get pregnant
• Patients who participate in concurrent clinical trials or previous clinical trials within 30 days of administration
• Other cases where the investigator deems the patient ineligible for participation