janniebug, i am sitting at home right now recovering from knee surgery done last monday. i too was having horrible pain when walking and had felt a pop in my knee.. it wasnt a tear in my Miniscus ( however you spell it). they did however go in and remove what they call a plica, which is a fiberous tissue that sometimes can get inflammed and hang on your leg bones... while they were in there they had to scrap my femur as it had a place where the bone was splintered....
I will be thinking about you. I hope that they can find what is causeing you this pain.. believe me i feel you on the pain... i know how bad it hurts to even try to walk.
let us know what they find ok???

((((((((((((janniebug)))))))))))))))