I had a dislocated knee cap 2 years ago. Not nearly as bad as Boozers, mine was just slightly off kilter. Took me about 3 months of physical therapy 3 days a week to get back to being able to run on it and another 2 to be able to do any cutting of any kind.
Of course my therapy wasn't as intense and regular as athletes can get, plus, being about 20 years younger than me he's got better recovery time. If there is no tendon damage, it's a matter of retraining the muscles to hold the knee cap in place.
It's an extremely painful injury though. When that knee cap is off even just a little bit, it's rubbing bone on bone.
