ANkle Arthritis?

4 years ago my ankle was fractured and displaced. Had emergency ORIF surgery. Developed avascular necrosis of the talus so spent months in a custom brace. After, Fibula was deformed from a break in it but ankle was pretty good - no pain, good (but not full) flexibility. For the past 1 & 1/2 months have been experiencing snapping (peroneal tendons I believe), creaking, popping, etc and swelling. Flexibilty still good. Didn't hurt the ankle in any way. Weather's been very hot & humid, been wearing sandals without orthotics.

Orthopedist x-rayed it; no difference from last year's x-ray when I didn't have these symptoms. He said arthritis was setting in. :( Just gave me surgical options when it worsens, no preventative measures. So my questions:
1) Would any physio help keep it from getting worse?
2) Can anything be done to stop the tendon snapping? -really uncomfortable!
3) What causes the tendon snapping?

Thanks for replying!