I still don't understand what you mean by working out your neck
I have no idea what to tell you about your back, if you feel pain you should always stop. Definitly talk to a doctor about that though, just because a bone was broken doesn't mean it CAN'T be worked theres just DIFFERENT ways of working it. I would say to leave back off of your workout until you talk to a doctor and you know exactly what you can and can not do.