The big worry was that he tore his meniscus, which is a protective layer around the knee and between the thigh and shin area (I know I'm really dumbing it down). If that was torn his recovery would be a lot slower and he probably wouldn't have full function again, and would be arthritic the rest of his life. But good news, it wasn't torn! And she also said that it was so recent that there wasn't any damage to the bones either! All this because we got him into surgery so quickly. In addition, they said that a fellow using laser technology to heal stuff will be at their clinic tomorrow for a presentation, and they're going to use it on Trakker for us! I guess it's supposed to help post-operative healing or something like that, and he's just going to happen to be there.
Anyway, I won't get to see him until tomorrow when we pick him up, but it's pretty good news all around so far :)