Any one had Avascular Necrosis or Osteonecrosis or AVN?

I was diagnosed with Avascular Necrosis of both hips about four years ago by then I had been on Propecia for 3 years. One Dr that did test on me told me that one of the causes of it could have been Nitric Oxide (NOS). Other then that no one could tell me why I got it. I was wondering maybe the Propecia could have caused it and wanted to see if anyone else got Avascular Necrosis.