(I'm a general & trauma surgeon & I know a fair amount about fractures. I also do some work with clinical informatics.).
As Tycho-Brohe, R1 and others have pointed out, "fracture" is a synonym for a break, which usually means of a bone. There are exceptions, for example cartilage can be fractured without a fracture of a bone. And there's also this unfortunate problem -
http://en.wikipedia.org/wiki/Penile_fracture.
As NavyOffRec points out it's helpful to know if you were seen by a doc for this, but unlike some other medical problems it's usually hard to tell if you have a fracture, sprain, strain - whatever - without seeing a doc & getting x-rays.
If you have had a fracture (diagnosed by a physician) then yes, you should report it. If you saw a doc, ER, were seen in the hospital or whatever, you (or your insurance company) got a bill - which would have a billing code (called an ICD-9 code) indicating a fracture. I'm not talking about your medical records (of course it would be there too), I'm talking about your billing records. These records get added to various databases and once the record exists, it literally will persist forever. Your permission for them to do that with your data is in the fine print of the forms you sign every time you get seen somewhere for health care.
I don't know if the Navy routinely checks outside health records for officer applicants (NavyOffRec mat be able to tell you), but even if they don't if there is a problem later (accident, illness) they can get to these records easily - and you don't want to be the person who has something in the past you should have reported but didn't. So if you have had a fracture in the past,that was diagnosed by a physician, you should consider calling your recruiter with something like "as I was thinking about this I remember I had a fracture of (whatever) and I forgot to list it on my paperwork".
The other thing to know is the medical standards for officer accession and for flight status are over in the DOC's corner forum. As R1 said, a healed fracture generally isn't a problem with flight status - but the actual determination is made by a military physician or flight surgeon based on these standards. I am not a flight surgeon, but if you want to give more detail I'll be happy to look up what you have in the standards & tell you if I think you'll have a problem. Or you can PM me the info if you want. There are some flight surgeons who sometimes visit the board who might help.
But in general if you have had a medical problem in the past and you're asked about it later for entering the military, buying insurance or whatever, you should report the information the best you can. With everyone moving to electronic databases & records it is really easy to get caught if you cheat.
