PAL FODOR, RALUCA FODOR, ARPAD SOLYOM, CORNEL CATOI, FLAVIU TABARAN, RADU LACATUS, CRISTIAN TRAMBITAS, BOGDAN CORDOS, TIBERIU BATAGA AUTOLOGOUS MATRIX-INDUCED CHONDROGENESIS VS MICROFRACTURE WITH PRP FOR CHONDRAL LESIONS OF THE KNEE IN A RABBIT MODEL Currently, microfracturing is the most commonly used cartilage repair procedure in cartilage defects. Our aim was to study the mechanism of in vivo cartilage repair in case of full-thickness articular cartilage damage of the knee using a three-dimensional matrix implanted without any preseeded cells in the defect. We also investigated whether platelet-rich plasma application after microfracture procedure of the knee is associated with improved outcome compared with traditional microfracture treatment alone in a rabbit model. Histological examination of the chondral defects, revealed the largest amount of new tissue with hyaline-like cartilage features in Hyalofast group. At 12 weeks from implantation of the Hyalofast scaffold demonstrated complete filling of the defect with hyaline cartilage in admixture with the scaffold and bone metaplasia in the deepest areas. In the PRP group, complete filling of the defect with an admixture of fibrous and hyaline-like cartilage tissue appeared with a discreet tendency of endochondral ossification. We confirmed the superiority of the autologous matrix-induced chondrogenesis compared to microfracture and PRP or microfracture alone in case of full-thickness articular cartilage damage of the knee.