Hi Devereaux
I can understand your concern. In my personal opinion, operative selling should have disappeared quite a while ago and I am concerned about the possibility of lymphedema too. Also, there have been reported cases of leg lymphedema from joint replacement.
Your best bet is to get (demand don't ask) a referral to a ceritifed lymphedema therapist in your area for a complete evaluation. They will be able to determine by physical examination whether it is edema or lymphedema.
Pat