Unicondylar tibia implant devices (200, 300, 400, 500, 600, 700, 800, 900, 1000) having a bone facing, distal side (134) that can be detailed with cement fixation features and may include any of or a plurality of grooves, pegs (136a), fins (136c), rails, cavities (136b), and/or coating whereby the geometry of the implant device (200, 300, 400, 500, 600, 700, 800, 900, 1000) improves implant to cement or cement to bone fixation characteristics exceeding that of a traditional flat surface. The implant device (200, 300, 400, 500, 600, 700, 800, 900, 1000) may also include a proximal side (138) facing away from the bone facing, distal side (134) having a geometry that can provide either articulating (cartilage and meniscal substituting) or to receive a secondary device coupleable to the implant device on the distal side of the secondary device that features an away from bone facing articulating feature. Additionally, the geometry of the implant device (200, 300, 400, 500, 600, 700, 800, 900, 1000) in anterior-posterior and medial-lateral directions, among other directions, provides a variety of improvements relative to currently available devices.
