No one should be.
I suppose Jacko's input would enlighten us more definitively, however it is my experience from injuries and witnessing others, once you dislocate a bone it is more likely to happen again.
This is why I have been saying all along that ERod should be on a regular regimen of quad exercises. That would help keep the patella in place.
Also I think the kid is a dope and will continue to be a Leon Spinks type to whom bad luck will always accompany him.