Abstract: An implant, artificial or semi-artificial at implantation, for repairing an articular cartilage and osteochondral defect site in a mammalian, such as a human. The implant having at least a first surface and a second surface. The first surface shaped for being press-fitted into the defect site to create an interface between the first surface and a bone-cartilage region of the defect site, and the second surface shaped for being press-fitted into the defect site to create an interface between the second surface and an articular cartilage region of the defect site. The implant being seeded, prior to implantation, with chondroprogenitor cells, including superficial zone chondroprogenitor cells.