One of my aunts is a such a specialized teacher; her program is called "emotional support" or something to that effect. From what I understand it's a classroom in the same school building and the students sent to her classroom are troubled in frequently very sad ways which she won't discuss in specifics. She's accountable to the same principle that the normal teachers are.

From what I know of this sort of program, it seems to be a sincere attempt to help kids, not merely brush them off into a corner to forget about them. I don't know how often it's successful, but I think in that school district at least it's well motivated. From what I know of it, it seems like a much better system than allowing those kids to disrupt normal classrooms.