95% of those above 240 matched into ortho so yes, step one is very very important but I would say AOA is more important 97% of those who were AOA matched. So if you have both over 240 + AOA, then you have a 99.9% chance of matching. GOod luck.

step one takes you only so far... a good score can help secure interviews, but once invited, they look at other things like personality, hobbies, research, interest in their program, life goals etc. a lot of the interview stuff seems pretty random as far as getting interviews. there is no single thing that guarantees an invite... even the best applicants get turned down by a few places. so, to answer your question, a good score might get you more interviews, but it wont make you a great applicant by any means. also, there is a surprising amount of research that has been done on this subject... try pubmed. historically, step I, AOA, and knowing the applicant (by doing a rotation there) are most important.

I do agree with the previous post. I do also want to add that the reputation of your school has a lot to do with it. If you are AOA and have 240+ then you should get a lot of interviews no matter where you come from. If not and you come from a sub-par medical school, then you really need to do something to set you apart. bottom line is, study hard and do lots of aways to increase your chances