I had a torn ACL and some of the symptoms are your knee feels like it's "popped out of joint and then slides back in", when this happens it usually swells and puts you out of commission for a couple of weeks. Another is when you lay down on your back put your leg up in the air, try to keep it as relaxed as possible. Take a hold of your calf with one nad and your thigh with the other, try to see if there is any "give" when you push them in opposite directions. The best way to tell is going and seeing your doctor though. He or she will be able to tell if there is a problem and recommend a specialist.
Good luck, I hope that you don't have an ACL injury, the surgery isn't a whole lot of fun to recover from. But it's worth it once you have recovered.
Keep us informed as to what you find out.
Kathy
