Cruciate replacing artificial knee

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

• a femoral component configured to be mounted to a femur;
• and
• a tibial component configured to be mounted to a tibia, the tibial component configured to engage the femoral component to form the knee joint prosthesis;
• wherein the femoral component and the tibial component are at least partially connected together by a geared arrangement, the geared arrangement including a femoral gear disposed on the femoral component and a tibial gear disposed on the tibial component, wherein the femoral and tibial gears are meshed together,
• wherein for each of the femoral and tibial gears, a posterior toothed segment of each gear has a curved path that follows an arc of a circle, and an anterior toothed segment of each gear follows a helical path,
• wherein the posterior toothed segment of each of the femoral and tibial gears includes a plurality of interconnected gear teeth, wherein each tooth of the interconnected gear teeth extends (i) along a horizontal longitudinal plane passing through the knee joint prosthesis and (ii) normal to a vertical sagittal plane passing through the knee joint prosthesis, and
• wherein the anterior toothed segment of each of the femoral and tibial gears includes a plurality of interconnected gear teeth, wherein each tooth of the interconnected gear teeth of the anterior toothed segment extends along a plane that is oblique to both the horizontal longitudinal plane and the vertical sagittal plane.