A joint prosthesis (10) includes a first component (12), a composite component (14) and a bearing component (16). The bearing can be mounted on and fixed to the composite component and has an articulation surface (17) to articulate with an articulation surface of the first component. The composite component has an extension (30,32,34,36,38) for stabilizing the component when implanted. The extension has an end (40,42,44,46,48) opposite the bearing. The composite component includes a porous base or preform (82) moulded to a solid polymer portion (80). The solid polymer portion engages the bearing component and extends into the extension and defines the end of the extension. The bearing is made of a different polymer. The composite component may be made by injection moulding.
