Is There No Treatment For Avascular Necrosis Of The Kneecap After Total Knee Replacement, And Do I Have To Live With The Pain Permanently?

I had a total knee replacement 2 years ago. I am having pain in the upper portion, so my doctor saw me and told me (with an xray) that my kneecap is suffering from a vascular necrosis. He said there is nothing to do except lose weight. Is that true? I have to live with this pain the rest of my life?