The implanted is constructed with a metal base element and a plastic part which is elastically mounted on the base element and carries a metal grid structure for the ingrowth of bone tissue. The elastic mounting is provided by a prop which extends from a body portion of the plastic part into a depression in the base element. The prop is received in the depression with lateral play to not only hold the mutually facing surfaces of the base element and plastic part from each other but to permit lateral play. The floating suspension permits inevitable micromovements between the metal implant and the plastic part to be absorbed and not transmitted directly to the bone tissue which grows into the metal grid structure.