Elderly chinchilla with possible broken/dislocated leg?

Hi everyone. I was hoping someone would give me advice. My oldest chinchilla Poppy who is 15 years old had a nasty fall last night and seems to be limping and not using her back left leg. She was laying down a lot last night but this morning she seems to be fine and is sitting on both legs but I still don't think she is putting much pressure on her back left leg. I'm worried because of her age that the vets will either put her to sleep or she wont come out of the anisthetic if surgery is needed. She's such a healthy chin at her age and is a cherished family member to us. Has anyone else had experience with older chinchillas and this kind of injury and can help me please???