Revision Knee Replacement Surgery
Sometimes it is necessary to re-operate on a knee that has already had a total knee replacement. There are a variety of reasons that would necessitate this. The plastic liner between the resurfaced femur and tibia can wear out. Most modern day implants allow for a new plastic liner to be implanted without changing the other components. The quality of these new inserts and the mechanism that locks them into the tibia tray has continued to improve wonderfully. One of the most frequent conditions that necessitates a revision knee replacement is continued pain or stiffness after the prior total knee surgery. Commonly, this is due to the complex soft tissue sleeve that supports the knee not being balanced or the components not being optimally positioned. Revision may also be required after a fracture or infection.
Frequently, the revision surgery is more time consuming, requires more surgical skill and special equipments. The dissection is often more extensive and the reconstruction more complex. It is often necessary to remove components that are not loose. This can be difficult and destructive. One of the consequences of the plastic liner wearing is the production of very tiny particles of plastic. These can incite an inflammatory process and stimulate the resorption of the bone that supports the implants. This condition is called osteolysis. The implants can then become unstable or loose. It becomes much more difficult to place new components when the bone bed that is needed is compromised or simply missing.
Fortunately, modular revision knee systems have been developed which allow us to address these varying problems with more consistency. Often, stems are attached to the femoral component or tibial tray and inserted up the femur or down the tibia to help stabilize it. Wedges and platforms may also be necessary to help recreate the natural joint line more exactly. The plastic inserts that articulate with the femur also tend to be more engaging.