A tibial prosthesis includes a tibial platform having a medial-lateral center and an inferior surface matable with a resected proximal tibia, and a modular keel that is fixable to the inferior surface and adjustable in a medial-lateral direction with respect to the medial-lateral center of the tibial...http://www.google.de/patents/US6506216?utm_source=gb-gplus-sharePatent US6506216 - Tibial tray with adjustable keel
