Hi Connie:
I'm not sure if there is any relation. I probably had the joint tenderness before this, but never noticed it because of the uncontrolled adhesion pain (no, I don't have endo, just adhesions). I was on major doses of NSAIDs for an extended time frame, then on high doses of Percocet for about 6 months before my GP put me on Oxycontin. It was after I started on the Oxycontin that I noticed the tender joints, and it is entirely possible that this is from arthritis, as my father was crippled with rheumatoid arthritis for years before he died.
Sorry I can't be of any more help than that, but this is my experience. Hugs,
Nancy in NB