I had a dog rip the wing off of one of my roosters last August. There was about an inch of bone remaining. There was also several shards of bone stuck into the surrounding muscle. I flushed it out with a saline solution then I used a scalpel to remove the remaining bone and severed muscle. Then I flushed it out again and stitched it shut. That was unnecessary though the bird pulled the stitches out the next day. A large black scab formed over the entire injury and it took 4 months to heal.
Here he was last August-
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Here is everything I removed from him.
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Here it is stitched up.
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And here he is that December. To bad I did not take any pictures in between. I didn't have to medicate him at all, birds immune systems seem to be a lot stronger than humans and mammals. It was lat in the summer when the injury happened but there was still flies. I put him in a crate with a fan pointing right at him to keep any flies away. It seems like the nervous system gets overloaded on birds when they get an injury like this. I don't actually know but they just have no reaction to the cuts and stitching on the spot where the main injury is. But then will have reactions if you go poking around on the other side of their body. If I had to guess I would say their nervous system gets overloaded when something like this happens and they just don't feel pain in that area until a day or two afterwards. I have noticed they have reactions when I would try to look at their injury and how it was healing.
We had a duck get her wing broken by a fox and we amputated the entire thing, during the surgery she just stood on the table we didn't even need to hold her. We put a dish with water and some food in it in front of her and she started to play in it and eat the pellets as we were cutting her wing off. She didnt flinch the entire time. At the end of it we accidentally cut a small blood vessel that was deeper inside the injury and she did have a reaction to that. That duck made a full recovery too but we made the mistake of leaving some of the bone in her and so it didnt heal and we had to go back and open it up and remove it a few days later.
I'm not sure what I would do in your situation or how the bird is acting but if that bone stays in there with a sharp edge and you can't get skin to regrow over it then it probably won't heal. With the duck we left about an inch in her but we smoothed it down so it had no sharp edge.