It's not as simple as picking programs in your "tier"...most programs consider themselves top tier - especially in a competitive field like ortho. Sure, a community program knows they don't have the name recognition of a place like Harvard or HSS, but their argument is they focus on producing top tier surgeons - not academic docs. Bottom line - at the end of the day they know they're not going to have to go very far down their rank list to fill their spots.
I do agree that board scores are probably the most important factor in getting interviews, but there are a couple caveats. First, an interview doesn't equal a high rank (or even being ranked at all) by that program. A lot of programs in one region of the country may interview a certain number of candidates outside their region just to prove they don't discriminate. However, they may have no intent of ranking anyone from outside their region because in they're mind you: a. may not want to be there, or b. may come and then not stay in the area to practice.
The second caveat is that board scores alone are not enough. I'm fully convinced that part of it is based on how many applicants from your school are applying to programs in a given region. I'll use my own experience as an example.
I went to a small, private school in the SE that few people know of - we don't have a home ortho program. In a class of 60, 8 of us applied to ortho. Obviously, we ALL applied to every program in the SE. We also all had similar stats (i.e. Step 1 in the mid 240s - mid-250s, and 3 of us were AOA). In other words, we were all great candidates on paper. Yet, I was denied interviews at MOST of the programs in the SE where I applied, including my own state med school! Why? My hypothesis is that applicants from my school flooded the market. Programs that only take 3-4 residents a year didn't want to interview 8 candidates from the same school (regardless of how qualified) because if they ranked us all, there is the theoretical chance we may all match there.
So my advice would be - apply BROADLY. I scored 246 on Step 1 and was senior AOA and out of 51 places I applied I was only offered 14 interviews. When you do interview out of region, be ready to give specific reasons why you would enjoy living there. Sub-Is can help prove this. Just be careful - as we've discussed on here, Sub-Is can be your best friend or the kiss of death. It's not just about working hard - it's about working hard, AND being a cool person, AND being prepared, AND managing to not tick off even ONE person for an entire month.
Good luck!