While on a Boy Scout outing many years ago my nail was crushed by an old water pump. It turned very dark purple/black and the doctor actually drilled a hole in the nail to relieve the pressure. I had to ice it for some days until finally the nail came off. There was a very thin new nail underneath. Once the old nail fell off the new nail started growing in at regular thickness. For quite a few years afterward I noticed a difference in that nail, it was much smoother than any of the others. That is no longer true.

I was only 11 or 12 years old so your experience may be different. I know I don't heal like I used to. Good luck.

BTW, it hurt like hell.