Hi @marsher1 and welcome to Mayo Clinic Connect. Sorry to hear you are having troubles.
I moved your post here so you could socialize with other people who have had burning long after their knee surgery.
Burning pain 6 years after TKR: https://connect.mayoclinic.org/discussion/burning-pain-6-years-after-tkr/
You might also like to read this discussion.
Severe Burning Pain after Knee Replacement: https://connect.mayoclinic.org/discussion/severe-burning-pain-after-knee-replacement/

Are you currently taking anything to help with the burning? How long does it last?