Abstract
It is well known that articular cartilage in adults has a limited capacity for self-repair. Numerous methods have been devised to augument its natural healing response, but these methods generally lead to filling of the defect with fibrous tissue or fibrocartilage, which lacks the mechanical characteristics of articular cartilage and fails with time. Tissue engineering combines aspects of cell biology, engineering, material science and surgery to generate new functional tissue and provides an important approach to the repair of articular cartilage lesions and, ultimately, functional success. The purpose of our study was to perform experimental resurfacing of articular cartilage in 18 sheep using different techniques: before implantation in all sheep a full-thickness chondral lesion of medial femoral condyle was created; subsequently, autologous chondrocytes seeded into the matrix were implantd into five sheep; a periosteum flap was implanted in five sheep; and, as source of growth factors, adipocytes by vascular peduncle of Hoffa tissue were implanted in five sheep. The reparative tissue of the chondral lesion was compared with uninjured contralateral knee. The results present the bonding between implantation tissue and host tissue, preservation of phenotypic stability of chondrocytes culture, standard dosage of growth factor secreted by adipocytes and characterisation of the histological properties of reparative tissue, comparing different surgical techniques.