Rotatable joint prosthesis with axial securement

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.