Hey, someone asked a similar question recently, here's what I told them:
If you're interested in sports medicine and orthopedics, you might consider checking out the University of North Carolina, Chapel Hill, they offer a paid residency program in orthopedics for FNPs: http://www.med.unc.edu/ortho/mededuc...ner-fellowship
I don't think it's strictly necessary, but it would undoubtedly help
If you want to be an NP with a focus on sports medicine I get the impression that it's possible, however, I have no idea how many opportunities there are for it. Let me know if you do learn more though, I was once kind of torn between the nursing route and physical therapy, and I'm still interested in sports medicine.
Sorry, I really don't know anything beyond that and I just found that randomly on a google search months ago. For any specifics into this program I would recommend contacting them directly. I wish I knew more programs (or residencies in general) but the only others I know of are a community health one in Connecticut and that Columbia's DNP includes a year residency (I think).
Good luck, sorry I can't be of more help.