Clinical Trial for the Regeneration of Cartilage Lesions in the Knee

Inclusion Criteria: * Patient is ≥18 and ≤65 years old at time of screening. * Patient has a localized articular cartilage defect of the femoral condyle and/or the trochlea of the knee. 2 localized cartilage defects are accepted if the total defect size is ≤ 8 cm2, both cartilage defects are located at the femoral condyle and/or the trochlea and both cartilage defects are to be treated with N-CAM or N-TEC. * Patient has a defect of grade 3 or 4 according to the ICRS classification. * Patient has a defect size ≥2 and ≤8 cm2 as assessed by MRI/arthroscopy. * Patient has an intact (≤ICRS Grade 2 ) articulating joint surface (no "kissing lesions"). * Patient has an intact meniscus (maximum 1/2-resection). * Patient has a stable knee joint or sufficiently reconstructed ligaments. If not, ligament repair has to be done during the operation or within 6 weeks of the planned cartilage treatment. * Patient has a maximum baseline score of 75/100 in the KOOS subjective knee evaluation. * Patient is willing and able to give written informed consent to participate in the study and to comply with all study requirements, including attending all follow-up visits and assessments and to complete postoperative rehabilitation regimen. Exclusion Criteria: * Patient is the investigator or any sub-investigator, research assistant, pharmacist, study coordinator, other staff or relative thereof directly involved in the conduct of the protocol or in a dependency or employment with t…