Follow-Up Study of CARTISTEM® Versus Microfracture for the Treatment of Knee Articular Cartilage Injury or Defect

Inclusion Criteria: * Patients with knee joint cartilage defect or injury of ICRS (International Cartilage Repair Society) Grade 4 confirmed by arthroscopy (At screening, patients diagnosed as such with an MRI may be included) * Male or female patients at least 18 years of age * Patients whose lesion (unilateral joint) is 2 ㎠ \~ 9㎠ in size * Patients with articular swelling, tenderness and active range of motion of Grade 2 or below * Patients with pain in affected joint of 60-mm or below on a 100-mm VAS (visual analogue scale) * Patients with adequate blood coagulation activity: PT(INR) \< 1.5, APTT \<1.5×control * Patients with adequate renal function: Creatinine ≤ 2.0 ㎎/㎗, levels of proteinuria measured with Dipstick: trace or less * Patients with adequate hepatic function: Bilirubin ≤ 2.0 ㎎/㎗, AST/ALT ≤ 100 IU/L * Patients who have received no surgery or radiation therapy in the affected joint within the past 6 six weeks, and have recovered from the side effects of such past treatments * Female patients of childbearing potential must agree to practice adequate methods of birth control to prevent pregnancy during the study * Patients whose physical examination results show no ligament instability of Grade II or above (Grade 0: none, Grade I: 0-5 mm, Grade II: 5-10 mm, Grade III: \>10 mm) * Patients who voluntarily agreed to enroll in the study and signed an informed consent form Exclusion Criteria: * Patients with autoimmune disease or the medical history * Patients with infections requiring parenteral administration of antibiotics * Patients with myocardial infarction, ischemic heart failure, other serious heart conditions or uncontrolled hypertension, or any medical history of such diseases * Patients with serious internal diseases * Patients who are currently pregnant or nursing * Patients with psychotic diseases, epilepsy, or any history of such diseases * Patients with alcohol abuse * Patients who smoke excessively * Patients with chronic inflammatory articular diseases such as rheumatoid arthritis * Patients who were enrolled in any other clinical trials within the past four weeks * Patients who had been administered with immunosuppressants such as Cyclosporin A or azathioprine within the past six weeks * Patients whose physical examination results show ligament instability of Grade II or above (Grade 0: none, Grade I: 0-5 mm, Grade II: 5-10 mm, Grade III: \>10 mm) * Patients with a known history of hypersensitivity/allergy to gentamicin * Patients whom the principal investigator considers inappropriate for the clinical trial due to any other reasons than those listed above