The general idea is: surgery and all specialties, rads, ortho, derm are all ridiculously competitive and you have to do as well as humanly possible...if we said you needed a 225 would you try to get just a 225? You should try to blow away Step I...If you have already taken it and are lower than you would like, you have to distinguish yourself in some way (research, publishing, do a great rotation).
And, if you want FP, IM, Peds, etc. you simply have to be in the top 100% of your class with a passing board score.