I hope you find another orthopedist. This one sounds like a douche.

I had a bursa behind my knee, and it seemed like it was more from misalignment and twisting. Im the same weight now as when i had it, and it hasnt come back. So i dont think losing wgt would necessarily fix it. Plus im the same hgt as you (i shrunk!) and i weigh way more. Im not running any marathons, but i would change shoes and change docs!