In the case of a failed knee replacement, a revision knee replacement can be performed to address the issues. Failure of knee replacements can be due to loosening over time called aseptic loosening or due to infection. Perceived instability or pain might be the early signs of a failing knee replacement. During the procedure, I will remove the prosthesis or parts of it, and replace them with new ones. In many cases, only one component of the artificial knee needs to be replaced, while in other cases all of the parts (the femur, tibia and patellar) need to be removed. When the components are removed, the knee is rebuilt with metal parts or bone grafts. Because the bone may be severely damaged, I may not be able to use standard knee implants, in which case, he may need to use very specialised implants to provide extra stability and support. If failure of a knee replacement is caused by infection, the revision surgery will be a two staged procedure. The first part consists of removal of the components, cleaning of the joint and the use of an antibiotic loaded cement spacer. Once it is clear that the infection has cleared up the new knee replacement will be performed.