If you crush the boards, and you are a decently like able person, you can be pretty much any type of doctor coming from a DO school. However, even if you crush the boards, as a DO you will probably never end up at a top intuition. You will likely go to a mid-tier Acgme residency, at best, for the lesser competitive fields, like internal medicine, or an aoa residency for more competitive fields, like ortho. There are exceptions, though. DOs are welcome at top PM&R and anesthiology programs.
So you can be an ortho surgeon relatively easily coming from a DO school, but you are not going to be receiving your training from any place people have heard of. I'm not saying the training is bad or anything; it's just kind of unknown. It probably doesn't matter anyway.
Board scores do correlate somewhat with mcat scores.