As soon as you said meniscus and couldn't move your knee I said surgery. If you tear your meniscus bad enough to have it dislodge and lock up your knee, you're heading to the surgeon. Since you did it via a torsional movement, I'd be surprised if there's no ligament damage as well. Either way, that bitch is gonna be sore as FUCK tomorrow.
I did something similar season before last. I only tweaked my knee bad enough to bruise my meniscus, but that was still bad enough to result in a grade two MCL tear. Luckily it was the MCL, that's not a big deal.