Patent ID: 11963879
Assignee: BEIJING NATON MEDICAL TECHNOLOGY HOLDINGS CO., LTD.
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 0:
1. A femoral prosthesis, configured to be mounted to a human femur and cooperating with a tibial prosthesis configured to be mounted on a human tibia, the femoral prosthesis comprising:
a femur body having a joint surface, the joint surface of the femur body comprising:
a first joint surface portion for abutting the tibial prosthesis within a first knee flexion angle range from a first knee flexion angle to a second knee flexion angle, the first knee flexion angle being 0° and smaller than the second knee flexion angle, and
a second joint surface portion for abutting the tibial prosthesis within a second knee flexion angle range from the second knee flexion angle to a third knee flexion angle, the second knee flexion angle being smaller than the third knee flexion angle; and

a cam portion coupled to the femur body,
wherein:
at the second knee flexion angle, the first joint surface portion has a first radius of curvature, and the second joint surface portion has a second radius of curvature;
a joint surface of the cam portion configured to initially contact a protuberance of the tibial prosthesis is an anterior joint surface when the femoral prosthesis moves from an extended state to a flexed state, and a center of a circle of the anterior joint surface of the cam portion is located in a first quadrant of a rectangular coordinate system established with a center of a circle with the second radius of curvature in a sagittal section as an origin when the femoral prosthesis is in the extended state; and
a line connecting a center of a circle with the first radius of curvature and a center of the circle with the second radius of curvature is tangent to the anterior joint surface of the cam portion at the second knee flexion angle in the sagittal section.