I assume when you say you dislicated your knee, you mean that you dislocated your patella (kneecap), as a complete knee dislocation is a highly traumatic event, and usually involves rupture of all the ligaments of your knee.
That said, I think there should be no real reason to avoid skating. Start by a land training program consisting of weight work to build strength and endurance in your legs and especially your core. A functional training program involving body weight exercises, and balance training would be great. Work on cardio using the eliptical or the bike, I would avoid the impact of using the treadmill or excessive running.