What is Knee Replacement?
A knee replacement is the replacement of all or part of the (gliding) cartilage surfaces of the knee’s three working parts.
This may include:
- Femoral Component: Femoral condyles are at the lower end of the thigh bone. The part that replaces the femoral condyles, the femoral component, is made entirely of metal. It fits over the end of the femur like a cap. This part may be
cemented to the bone, but is frequently inserted without cement.
- Tibial Component: This is the upper part of the tibia (shin bone). The tibial component is made entirely of plastic, or a combination of metal and plastic. The metal forms the base of this part and is in direct contact with the tibia. The
plastic, which is a very durable type of polyethylene, is inserted on top of the metal. This serves as a cushion and a smooth gliding surface between the metal of the femoral and the metal of the tibial parts. Most tibial components are secured to the bone with bone cement. However, the tibial component may be used without cement and secured with bone screws instead.
- Patella Component: This is the undersurface of the patella(knee cap). The patella may be all polyethylene, or a combination of metal and polyethylene. This part may be inserted with or without cement. The decision to use the prosthesis with or without cement is made by the surgeon based on a complete understanding of your case and all factors involved.
A total knee replacement involves replacement of all the cartilage surfaces of your knee. In certain patients, a partial or unicompartmental knee replacement is indicated when the arthritis involves only a part of the knee. This procedure preserves more of your natural knee. The decision on how much of your knee to replace is determined before and during your surgery.
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