UPDATE:
Bear went for his second round of shots yesterday afternoon, and the vets didn't even recognize him! He is a robust 12.4 pounds, and his wound is healing nicely.
They did have to shave him a little so they could look at the wound, and a concern is that the skin might fold as it heals. He might have to have another surgery in the future, but for now he is progressing nicely. His ankles are as good as new, and his fur is growing in very well.