Hi Angie8281,
I also have AVN in my hip. From what I've researched, it seems that (hip) core decompressions have unreliable results and unfortunately most cases end up eventually having a hip replacement. Because of that uncertainty, I'm opting to go ahead and get a hip replacement myself. Out of curiousity, did they pull your graft from your fibula? Although I'm only 28 and my replacement will require a (pelvic) bone graft to hold the new stem in place, I'm eager and ready to regain my quality of life in hopes that this will provide pain relief. CD wasn't an option because of my particular condition/situation, but even if it was I'd look to something with a greater long term success rate.
Have you seen any other doctors? If I was you, I'd get as many opinions as I could until someone was willing to find a proactive resolution to your pain. Despite your MRI, AVN pain is nothing to scuff at afterall! I feel for you and truly hope you find some relief!