Rescue puppy surgery

I found this stray puppy who had been hit by a car. Took him to the animal ER and they said he needs surgery on his pelvis and knee. The surgery would cost $1100 dollars. I have already payed to house him at the vet and provide some basic care but I cannot afford to also pay for his surgery. Any help would be appreciated! I'm trying to raise money to pay for the surgery and the post surgery medical bills and help a foster post surgery. He is a sweet boy and the vets think he could make a full recovery with surgery.