A joint prosthesis system includes a femoral component that has an articular side, a bone facing side, and medial and lateral condylar portions. The medial and lateral condylar portions at least partially define an intercondylar recess located therebetween and have a first concave surface extending in a mediolateral direction across the medial and lateral condylar portions. A first modular component has a second concave surface and is connectable to the femoral component such that, when the first modular component is connected to the femoral component, the first and second concave surfaces come together to form a transverse opening extending in the mediolateral direction. A first tibial assembly has a baseplate component and a head extending therefrom. The head defines an axle opening that extends therethrough. An axle is configured to be received within the transverse opening and axle opening so as to connect the tibial assembly to the femoral component.