An implant for repairing an articular cartilage defect site including an implant fixation portion with an upper segment and at least one bone interfacing segment and a top articulating portion with an articulating surface and an engagement surface. The upper segment includes a supporting plate with a first locking mechanism segment. The engagement surface includes a second locking mechanism segment. The first locking mechanism segment with at least two channels is structured to couple to the second locking mechanism segment with at least two protrusions. The at least one bone interfacing segment structured for insertion into the articular cartilage defect site. An implant including an implant fixation portion, a top articulating portion, and a locking mechanism with a first locking segment coupled to the upper segment and a second locking segment coupled to the at least one engagement surface and structured to couple to the first locking segment.