Can my 3 legged german shepherd hold pups?

i have a 16 month old german shepherd, she that a few months ago unfortunately had a car accident. she ran in front of a car and broke her back hind leg. we tryed to fix her leg but the operation was unsuccessful. so we had to amputate. she has had a very successful recovery she does everything that a normal dog does.she still jumps, still runs very fast. so my question is why can she not have puppies?