Knee prosthesis permitting rotary and bending motion - has hinge joint between tibial and femoral components with cammed, profiled surfaces cooperating with tibial stem

摘要

The knee prosthesis has two articulating stems, fixed in the femur and the tibia respectively. The tibial component has a central bore and a cammed, profiled surface which co-operates with a complementary surface on one of the hinge-joint components. Extending from the latter surface is a stem which fits into the bore. Rotation of the tibia relative to the femur causes the two profiled surfaces to ride up over each other so transforming to rotary movement into an axial displacement.