@suetex I think there are many triggers. It seems a normally healthy person is doing fine and then something sets it off. Over the last 4 years I have seen hundreds of reasons. From a day of over exertion exercising to a family member passing. Who knows. The medical field has no answers. I was under a considerable amount of stress and then got the covid vaccine. Wham. PMR hit me. I dont see a problem connecting a stressful surgery to setting off PMR. My point was that during the first year after stopping steroids I had two more flares. No particular reason. Stress maybe? It seems the body is in a delicate state of balance. Many have had other auto immunes show up during this time. I decided to not ride mine out like you did. I had a few extra prednisone so I took a 5 day pack. 20 -20-10-5-5 and stopped. Flare was gone. This was not approved by my Dr. Could it be a PMR reaction? Or maybe as you suggest a reaction to the surgery medication? I can't say for sure. I do think we can tell a PMR episode after having lived them once.