As far as the hips and knees go, it's a crap shoot. My dog has OFA certification for her hips (Labs are known for hip dysplasia so I wasn't going to get one that wasn't), but all it means is that the stud and bitch had no hip issues.
This sadly means nothing about the pups, just that the parents had no issues. She has already had one ACL replaced, her other knee looks like it will need one at some point when I have the money for it, and her back legs sound like a bowl of Rice Krispies when she walks - snap, crackle, and pop.
She's only 3, but she is already arthritic, stretches her back legs constantly, and goes lame for a day or so if she gets too much exercise. I have to be very cognizant of this when we play.