There's no set number for ortho interviews. The number that's quoted to be "in the game" is 220. But you can just as well get an interview at top programs with a 210 as with a 260. It's the total package that counts. Obviously the higher your score the better.

I have heard the same numbers as Dingleberry. 220 to be considered for an interview and then they start to look at the whole package. However, if it is your home school, you can expect this number to be lower...even down to 205 I have heard. Realistically, where you get interviews can be a result of a crapshoot...you'll get some interviews at places you did not expect and then get rejected at others you think were "golden" at.

Oh yeah, on one of my ortho rotations, one of the residents told the story of a med student with like a 190 on Step I and worked their ass off and took q2 call during an away, and ended up matching at a program.