If you can get involved, even very minimally, on a research project, that would be important. There is a portion of the application that asks about research, and I also feel like you should have a response for every part of an application (i.e. I hate haveing to leave an "N/A" or blank on an application).
Other than that, rock Step 2 (Do it early), continue your A's on your clinical rotations, and do some good aways. Getting into orthopedics isn't rocket science in the sense that all programs look in general for some basic things. I've essentially highlighted those things above.
Of all of those, I think the most important is doing aways. If you are truly interested in a specific location, aways in that location will help solidify your ability to get a residency spot. Of course, aways can backfire, but they also can significantly help. I don't know what the numbers show, but I would guess that > 67% of all ortho applicants match into a program where they rotated.