An artificial knee joint consists of the following parts, e.g.:
The surgeon will decide which materials will be suitable for each individual patient.
In many cases it is sufficient just to replace the damaged structures close to the knee joint. This involves fitting a femur joint replacement to the condyle and a tibial plateau replacement to the shinbone. A plastic insert acts as a low-friction bearing between the two. The back of the kneecap can also be replaced with a plastic cap.
This procedure is referred to as resurfacing as only the damaged surfaces are replaced. One benefit of this intervention is that the bone material is preserved and the important, supportive tendon structures are retained as much as possible. For this reason, this procedure is currently the standard knee replacement operation.
If the bone is unstable, there are large discrepancies in the leg axis or loose collateral ligaments, a procedure known as an axially supported knee replacement is performed. This artificial joint also consists of a femoral component and a tibial component. Both components have a long stem, which is anchored in the femur and tibia respectively during surgery. Together, the two components form a hinged joint which ensures a high level of stability, even if the collateral tendons of the knee joint are unstable. However, this method does involve removing more bone material in order to anchor the joint.
