My Mom Is Experiencing Chronic Pain In Her Right Ankle

My Mom is experiencing chronic pain in her right ankle She can't even hardly walk on it. She's been taking Ibuprofen and Naproxen to help with the pain which it does help a little but never takes the pain away. She has had it Xrayed and they said there isn't anything wrong with it. One DR told her she was just getting old basically and would have to deal with it. Not an acceptable answer as far as I'm concerned. Something else has to be wrong. Any ideas?