So I have a bad knee. The ACL was stretched and slightly torn several years ago and I needed to get surgery. Since then it has happened occasionally that my knee feels as though it "slips" slightly out and back into the joint. I suppose this may also be the ligament "slipping". Either way there is a distinct "slip" sensation and the knee goes out from under me for just a second before it is stable again. At any rate it typically hurts a while and swells a bit but I can pretty much walk it off no problem. Last night at work though my knee "slipped" and left me hardly able to walk. Since then it does not seem to have gotten any better though I was unable to get ice for it until several hours later. I also tried a knee brace but it seems to actually hurt more trying to get around with it on than with it off. I am still able to bend my knee within a limited range of motion (can not be fully extended or fully folded but most range is still there). So anyone ever have any similar issues? By the way, yes I will be going to a doctor if this issue persists. As far as I can tell the only thing I am likely to be told by a doctor is that I should stay off of it for a while, ice it, and keep it elevated (which I am doing currently) or I need surgery again. So if it does not get better over a couple days I will go to a doctor. I only want to try figuring out what this "slipping" sensation is and what sort of thing I might expect.