What is a knee replacement?
One can differentiate between a partial and total knee replacement. Typically a knee prosthesis consists of a metal part, which is fixed cemented or uncemented to the thigh (femur) and shin bone (tibia).
A polyethylene part (bearing) between the femur and tibia allows a normal range of motion and function of the knee joint.
Partial knee replacement
A partial knee replacement is indicated, when only some parts of the knee are affected by the osteoarthritis (OA). It can either be a medial OA (medial tibiofemoral joint affected), a lateral OA (lateral tibiofemoral OA) or patellofemoral OA. A total knee replacement is indicated when more than one part of the knee is affected by OA.
It is the general rule to replace as less knee compartments as necessary.
One can differentiate between a patellofemoral joint replacment, a unicondylar knee replacement and a total knee replacement.
The partial knee replacement (unicondylar knee arthroplasty) shown here consists of a metal femoral and tibial component and a mobile bearing polyethylene component.
Total knee replacement
A total knee replacement is indicate when more than one part of the knee joint (medial tibiofemoral, lateral tibiofemoral, patellofemoral) are affected by OA or osteonecrosis.
A total knee prosthesis replaces all parts of the knee joint. Fixation of the metal components can be performed using bone cement (cemented) or without (uncemented, press-fit).
A total knee replacement should only be implanted after an intensive non-surgical therapy including physiotherapy or injections. There is no return to a natural non-replaced knee after total knee replacement.
The total knee replacement shown here consists of a femoral and tibial metal component and a mobile bearing polyethylene component.