I've dislocated my right knee 4 times, the last one happened on Memorial Day. Each time it has happened I was playing baseball. Recovery period seems to depend on how violently the joint snaps back into place, more then how violently it was dislocated.

The first time I did it the bone bruise lasted for 8 months. This last time was the most brutal dislocation, of all, only lasted 4 weeks. The difference was that the last time the kneecap gently slid back in place as oppossed to snaping back.