Abstract: The kit for implanting a cementable endoprosthesis comprises a fitting instrument (3) and at least two components to be implanted, namely an endoprosthesis shaft (4) and a proximal centering and/or sealing element (1), the shaft (4) and the fitting instrument (3) being designed to be able to be coupled to each other, and the centering and/or sealing element (1) being designed to be placeable on the shaft (4) and to be displaceable in the direction of extension of the latter, and either the fitting instrument (3) comprising a limit stop part (3e) which forms a limit stop relative to the centering and/or sealing element (1), or a marking (6) being arranged on the fitting instrument (3) and on the shaft (4) in order to ensure a defined mutual position between the centering and/or sealing element (1) and the shaft (4).

Abstract: A tibia part of a knee joint prosthesis includes a tibia platform having a distal side, and an anchoring element. The anchoring element is arranged on the distal side of the tibia platform and attached to the tibia platform. In one embodiment, the anchoring element is formed by a shield having a height which is smaller than a width of the shield, and the shield has a U-, C- or V-shape as seen from the tibia platform.