When knee replacement has lived its life or when there is an infection in the knee replacement, sometimes the knee replacement implant the knee implant has to be removed, infections have to be removed and the new implant has to be put in to place. This is done when a good knee replacement also wheres out over the period of time, this is quite an extensive surgery and it requires long hours of stay, requires long hours of surgical time and long days of stay in the hospital. Revision knee replacement is done for those who have failed primary knee replacement and return to normal it takes somewhere between 3 to 6 months