I'm currently in the healing process for a shattered knee cap.
I can't really remember what happened, I blame it on the pain killers and hitting my head. I remember I wasn't looking at the track, only at the guy in front of me's back tire. I'm on a hardtail, he's on a Orange 222, came flying through a rock garden, same speed as him, and obviously it wasn't as smooth for me. Got out of shape, hit a few things and then hit a tree. Spun 180 degrees and done a flip type thing. First thing to hit the ground was my knee, into the point of a rock. Second thing to hit was my head.
Got carried out by a bunch of guys from this site (Thanks!) and taken away in an ambulance. 9 days later, they operated. There were 8 distinct pieces, anda number of stress cracks.
It's exactly 3 weeks after the operation, and I started walking with no crutches today. I still have a splint on my leg, and a gnarly scar too.
I'm working on my exercises so I can get back ASAP. Basically, tense-and-hold the thigh muscle for 3 seconds, 100 times a day. Side ways swing 50 times a day, forward swing 50 times a day, backward swing 50 times a day, and bend the knee as far as it will go without pain 10 times a day.
Out of this whole experience, I've learnt one thing.
WEAR YOUR PADS.