The same thing happened to me. I went to TCI for my 6 month f/u and 2-3 stitches were still in the incision site and skin had grown over them. Dr. B. sent me right away to a plastic surgeon within minutes of his office to have them removed. He was concerned about the possibility of infection.
This is not uncommon for stitches to work their way out.....for some it is bcuz they have EDS and they r rejecting them..while with others they just may be missed when the others were removed.
Ur NS is the best one to address this and say which issue u may have.
My neurosurgery PA missed about four stitches. I found most of them within a 2-3 weeks and a friend removed them for me. I did have a bit of thread come out at about 5 months.