Abstract: A joint prosthesis system includes first and second components that are joinable to each other in a manner to inhibit the rotation of the second component relative to the first component. The prosthesis system includes a rotation-inhibiting mechanism that has at least circumferential groove formed in one of a portion of the first component and a portion of the second component and at least one rib formed on the other of the first component and the second component. In one embodiment the rib may be eccentric, and the groove and the rib are matable with each other upon mounting of the second component within the first component.

Abstract: A joint prosthesis system includes first and second components that are joinable to one another in a manner to permit axial rotation of one component relative to the other component while achieving axial securement of the two components. In one embodiment the joint prosthesis system is a knee joint prosthesis and the two components are a tibial tray and a tibial bearing insert. The tibial bearing insert includes a mating stem that has one or more positive surface features on its exterior surface. The positive surface features mate with axial slot(s) formed in a mating cavity of the tibial tray to enable insertion of the mating stem within the mating cavity. Upon insertion the positive surface features are engaged by a circumferential groove disposed distally of the axial slot(s). Misalignment of the positive surface features and the axial slot(s) enables proper orientation of the tibial tray and tibial bearing insert, and provides axial securement of the two components.

Abstract: A joint prosthesis system includes first and second components that are joinable to each other in a manner to inhibit the second component from withdrawing from the first component. The prosthesis system includes a securing mechanism that has at least one first surface feature (e.g. a negative surface feature), located on the first component, and at least one second surface feature (e.g. a positive surface feature) located on the second component. The first and second surface features are engageable so that, upon engagement, the second component is axially secured to the first component and the second component is able to rotate with respect to the first component. Preferably, the first surface feature and the second surface feature are adapted and dimensioned to engage and form a snap fit arrangement. In one embodiment, the joint prosthesis system is a knee joint prosthesis and the two components are a tibial tray and a tibial bearing insert.