Ligaments are the parts that hold the bones in their apt place that ensures proper action of the bones. In the case of a knee four such ligaments keep the bones and in place and damage to any one of the ligaments would result in knee becoming arthritic. Replacement of such ligaments by artificial means is called prosthesis. There are two ways by which replacement or substitution to ensure the bone in the right place could be effected. One is cemented knee replacement and the other is cement-less knee replacement.
Cemented Knee Replacement
This is the most popular process among the two and has a high success rate. In cemented replacement a special kind of cement called as polymethylmethacrylate is used which cements the joint with vigour and keeps the bone at its exact location. The cement creates a perfect fixing through mechanical bonding between the cement used and the bones. Such fixations have a long life of even up to 20 years. The life of it of course depends mostly on the activity level of the patient, body weight and also the health condition.
Failures in this kind mostly happen due to mechanical reasons and also biological reasons. Bio reasons are created when the bone debris is detected by the natural tissues and when they consider the joint as a foreign material they try to remove them and cause inflammation and also infection.
Cementless Knee Replacement:
This type of fixation mostly relies on the growth of the bone over the surface of the implant after replacement. Surface properties of the replacement are generally coated with a texture that induces natural growth of bones over it. To initially keep the bones in place artificial means like bolts and even pegs in cases are used that will be removed when the bone is retained and strengthen in a natural way. This process requires a long healing period as it relies on the natural growth of the bones.
High active persons have chances of failure in this process and debris created might create inflammation that could result in failures even. For short term replacement processes cementless knee replacement is found to work in an excellent way.