Apparatus for performing an open wedge, high tibial osteotomy, the apparatus comprising: a wedge-shaped implant for disposition in a wedge-shaped opening created in the tibia, wherein the wedge-shaped implant comprises at least two keys, laterally offset from one another, for disposition in corresponding keyholes formed in the tibia adjacent to the wedge-shaped opening created in the tibia. Apparatus for performing an open wedge, high tibial osteotomy, the apparatus comprising: a wedge-shaped implant for disposition in a wedge-shaped opening created in the tibia, wherein the wedge-shaped implant comprises at least two keys, vertically offset from one another, for disposition in corresponding keyholes formed in the tibia adjacent to the wedge-shaped opening created in the tibia, and a shear rib, laterally offset from the at least two keys, for disposition in a corresponding shear rib keyhole formed in the tibia adjacent to the wedge-shaped opening created in the tibia.