Talk to them. Honestly, just do it. You'll probably spend the rest of your life pondering what could have been. I can empathise with you regarding the abuse (my mother and I are victims of domestic violence), but as they're your parents just letting them know that you're well, with your own family, is showing that you're the decent human being in this situation. If they don't want to talk to you, then that's that; you tried, they didn't. You'll be showing more compassion for them in a few moments than they did in your childhood.
Abuse is impossible to forget, even more impossible to forgive. Never forget what happened, I sure as hell don't. For the past seven or eight years, I've lived with the events that happened to me and I'm going to have to talk to a judge, addressing an opposition lawyer, about EVERY minute detail, every date that I can remember. I can remember every date (December 13th, 2007; October 21st, 2008; October 22nd, 2010; July 13th, 2011; November 15th, 2012), every location (our home; the Hilton, Marko Island, Florida; our home; our Floridian house; our home; our home, respectively), every detail (how he reared his fist to me; how he grabbed my collar and then tossed me onto a bed; how he grabbed my mother's arm and severely bruised it before rearing his fist; how he chased me out of my own house; how he trapped my mother to a sofa by pinning her arms). Yet I have to show this man (not my father; parents divorced for seven years) compassion by not antagonising him, not provoking him, not screaming at him for what he's done. I wish I could, but I'm a person; I have empathy and compassion, things that this psychopath lacks.
By showing your parents that you have empathy and emotions, you're showing just how grown up you've become since leaving. I'm 20 this October and I can never imagine what you've gone through by living on the streets (contrasting to you, I've had a comfortable life) and fending for yourself.
Try and talk to them. If they push you away, your conscience is intact and better than you've felt before.