Modular artificial knee system

1. A modular knee joint prosthesis configured to move between an extended position and a flexion position, the modular knee joint prosthesis comprising:

a femoral component configured to be mounted to a femur, the femoral component having a first cutout or opening in a central region thereof for receiving a femoral insert;

a tibial component configured to (i) be mounted either directly or indirectly to a tibia, and (ii) engage the femoral component, the tibial component having a second cutout or opening in a central region thereof for receiving a tibial insert,

wherein the tibial component comprises an articular insert, and the second cutout or opening is formed in the articular insert, and wherein the articular insert is configured to be sandwiched between the femoral component and a tibial baseplate that is mounted directly to the tibia.

2. The modular knee joint prosthesis of claim 1 further comprising the femoral insert and the tibial insert.

3. The modular knee joint prosthesis of claim 2 , further comprising a blade protruding from the femoral insert and a slot disposed on the tibial insert, wherein the blade is configured to be positioned within the slot in both the extended and flexion positions.

4. The modular knee joint prosthesis of claim 3 , wherein the blade follows a helical trajectory to cause movement of the tibial component in either a medial or lateral direction as the knee joint prosthesis is moved to the extended position.

5. The modular knee joint prosthesis of claim 2 , further comprising a post protruding from the tibial insert and an opening disposed on the femoral insert, wherein the post is configured to be positioned within the opening in both the extended and flexion positions.

6. The modular knee joint prosthesis of claim 5 , wherein the post protrudes from a concave surface formed on the tibial insert, and the opening is disposed on a convex surface formed on the femoral insert, wherein the concave surface is configured to be positioned against the convex surface in both the extended and flexion positions.

7. A kit comprising the modular knee joint prosthesis of claim 1 and further comprising at least two of the femoral inserts having different geometries, and at least two of the tibial inserts having different geometries.

8. The modular knee joint prosthesis of claim 1 further comprising the femoral insert and the tibial insert, wherein the femoral insert is removably mounted within the first cutout or opening of the femoral component, and the tibial insert is removably mounted within the second cutout or opening of the tibial component.

9. The modular knee joint prosthesis of claim 8 , wherein the femoral insert is removably mounted within the first cutout or opening of the femoral component by a rail and slot engagement, and the tibial insert is removably mounted within the second cutout or opening of the tibial component by a sliding rail and slot engagement.

10. A modular knee joint prosthesis configured to move between an extended position and a flexion position, the modular knee joint prosthesis comprising:

a femoral component configured to be mounted to a femur, the femoral component having a first cutout or opening in a central region thereof;

a femoral insert positioned in the first cutout or opening;

a tibial component configured to (i) be mounted either directly or indirectly to a tibia, and (ii) engage the femoral component, the tibial component having a second cutout or opening in a central region thereof for receiving a tibial insert;

a tibial insert positioned in the second cutout or opening; and

a femoral gear disposed on the femoral insert and a tibial gear disposed on the tibial insert, wherein the femoral and tibial gears are configured to be meshed together.

11. The modular knee joint prosthesis of claim 10 , wherein the femoral and tibial gears are configured to be meshed together in both the extended and flexion positions.

12. The modular knee joint prosthesis of claim 10 , wherein the femoral and tibial gears have gear teeth.

13. The modular knee joint prosthesis of claim 10 , wherein at least one of the gears follows a helical trajectory to cause movement of the tibial component in either a medial or lateral direction as the knee joint prosthesis is moved to the extended position.