I had a left TKR 3 years ago last week.  After the surgery, I was fanatic about protecting the joint.  However, about 3 weeks ago I made the mistake of trying to push a piece of furniture on a bare floor and my knee has been hurting ever since.  It also feels like the prosthesis is slipping, not just front to back but side to side as well.

I am wearing a knee brace until I see my doctor (he didn't think I needed to come in sooner) and that seems to help, but I'm having to use the brace practically 24/7 because of the slippage I feel when the knee is not supported externally.

Any ideas on what could be causing this?  Am I looking at a revision surgery, which I cannot afford financially?