I was just messing around on my hardtail, hitting a little jump at the shop. I got the bike tabletopped off the jump, and couldn't bring it back underneath me, I instinctively put my right foot down when I landed casuing my knee to do some funky twisting. This is the knee that is sans ACL (can't have surgery until the spring), and it hurts like a biotch. Am I probably doing some cartilage damage when I do something to make my knee unstable?