Before I grew boobs I used to be a gymnast and I was doing a series of back handsprings on the beam and my spotter wasn't watching. When I fell, I missed the crash mats. Both knees landed on the gym floor. So I had to have reconstructive surgery. They were able to save the knee caps (the bone slightly underneath it was what had to be replaced to make the knee joint itself stronger) but I need to have both replaced. The problem is that once you have it done, it has to be repeated every 7-9 years and I'm too young to go there yet. So I'm trying to hold off as long as possible. I've had microscopic and reconstructive done on both.