Myself and the other M4s going into ortho at my school just put together a presentation on applying to ortho. What we noticed is that the new Charting Outcomes gives >250 Step 1 as a 90% match probability, but a 220 Step 1 still has a 50% match probability. You may close some doors for interviews, but if you are a well-rounded applicant that works hard and picks your away rotations well, an average Step 1 score shouldn't prevent you from matching.