i took the car to a frame shop for an alignment since my car has been really bad lately since i hit this curb..

and they said they cant do the alignment without fixing the right steering knuckle, its bent. they wanted $400, so i said no and figured i would come here and ask first. what is this piece? what does it do? does it sound likely that that is whats responsible for screwing up my steering wheel and alignment ? and possibly my bad 1/4 time? idk anything about these, please let me know guys, thanks