TT, from someone, like Tim, who is walking the same walk, the best advice I can give is if you don't have one, find a good orthopedic specialist/surgeon. There are some recent additions to treatments out there for knees and joints that may be options. The gel inserts and meds, like the Voltaren cream I told you about, may help.
I will continue to keep you, as well as the rest of the 'family', in my daily prayers.