^^ McGahee only tore all the ligaments in his knee, by the looks of the stitches in that picture it looks like he did alot more than just tear some ligaments. But yes, to see someone come back from an awful injury is still inspirational.
OP, what did you actually do to your knee in the accident? I'm gonna assume you broke a few bones based on that picture. But like everyone said, stick to what your doc's say and don't get brave like so many snowboarders do and think your good to try before your cleared to. Also, make sure you take extra special care of those stitches and the healing of it. I've seen people with similar incisions and they didn't take care of it and they got infected. That is bad news...