Bob:

The cause of Dups is still under investigation. It is highly unpredictable. It can easily go dormant and stay that way for years. However for many it continues on toward closing the fingers to the palm. While 45 degrees is livable, that's the position most surgeons say its time to treat if you are going with Open surgery. NA, your other option, can be done with as little as 30 degrees or so. In editor case, if the finger is progressing, don't let it go too long. The more the bend, the less successful will be the outcome. After one surgery I'm not shy arguing the case for NA as your best and first alternative to doing nothing.

45 degress is the point at which you should take action. By all means, try NA before surgery. You have nothing to lose, and much to gain if you can avoid surgery.