help or advice for protruding bone
Featured Stories on BackYard Chickens
As far as i know ducks can live happy lives with broken wing(s). Exposed bone is at risk of infection. You may be able to get a prescription for antibiotic and anti-inflammatory meds from a farm vet, wildlife vet or bird vet.
If your duck has made it this far after the injury and is eating ,drinking, and acting ducky I would personally try to save them.