That's a hard question and it will also be a hard decision because you've been looking forward to your baby . . .
I know for myself, knowing what you now know, I wouldn't continue with the purchase because of the fact that the poor baby does have a dibilitating disease and that you, yourself, might have to have surgery in the future. While it would be wonderful to think she might not need surgery, you have to expect that being diagnosed with hip luxation and ending up being arthritic, she'll be a very special needs dog and will probably end up costing a lot of money and a lot of worry . . .
It's just such a hard decision . . .I'm sorry you have to make it . . .