Method for performing an open wedge, high tibial osteotomy, utilizing an 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 one key for disposition in at least one corresponding keyhole formed in the tibia adjacent to the wedge-shaped opening created in the tibia, wherein each of the at least one keys comprises an interior bore for receiving a fixation screw, at least one fixation screw for disposition in the interior bore of the at least one key, and further wherein the apparatus is configured so that when the at least one fixation screw is received in the interior bore, the at least one fixation screw terminates within the bore.