I have major knee problems. They wouldn't dream of replacing then yet due to my age and the fact that they only last so long. I've had three lateral releases and the extensor mechanism all realigned. A lot of my symptoms were/are what you would consider a replacement for later in life.
Knee supports are fantastic, the adjustable ones with the straps on them are best as they are comfier but if the knee is very unstable a neoprene pull on with a knee hole is the best. They can be rubbish in hot weather (my tan line from before my op earlier this month is fantastic!!!) but it's worth it. You can't sleep in them. Don't spend a fortune £25 from boots etc is about right.
I tried glucosamine but didn't notice a big change, cod liver oil is good for the joints though.
Massage is painful and is now a big no go zone around my scars.
Heat and ice is one of the best pain relief methods. Hot water bottle= cheap and reusable and I always keep a small bag of ice in the freezer, just wrap it up before using for about 20 mins a few times a day. Only ice post op though.
PHYSIO PHYSIO PHYSIO, it's the only thing which makes any major difference before and after surgery. A good physio is a must, they have to be able to push you as the exercises get boring and can be painful. Im back on the exercise bike at mine in a week, oh the joys
hehe.
Sorry if this sounds a little bleak, but there is light at the end of the tunnel, most people find that after a full replacement they feel fantastic and anyone who I know that has had one has recovered very fast. If she isn't sure, get a second opinion, don't feel pressured into anything.