For reals, this is not even close to the first time this has happened. And I always just replace them. I've considered buying dpns in bulk. My favorite needle material is bamboo, but I've slowly been phasing out my bamboo circulars and substituting metal. Addi Turbos are OK, I guess. But this time, I really didn't feel like making a special trip to the local yarn shop just so I could continue my project (which ironically was a dog sweater).
So I chopped off the maimed region with a small handsaw.
Now to sharpen. I often fantasize about having a garage stocked with all the tools a person could need, but since we live in a condo it remains a dream. I'm not equipped with a full selection of metal files of various cuts (YET), so I used the one that comes on nail clippers. Classy. Slowly but surely, it got the job done.
He ended up quite a bit smaller than his brother, though.
But it's not all about the length, it's how you use what you've got that counts, right?