Hi, thanks for writing to HCM.
Your entire description suggests that you have an infected total knee arthroplasty
(unless proved otherwise).
Simple change of polyethylene insert will not serve the purpose.
You need a thorough workup and evaluation to rule out all possible causes of infection. Simple revision of knee joint without knowing the cause of failure will end in disaster.
So i suggest you to approach an orthopedic surgeon with good amount of experience in total joint arthoplasties and follow his advice accordingly.
Hope this helps