Absolutely no cooked bones and no weight bearing bones for dogs. These bones, leg and some consider beef necks to be weight bearing, are too dense for the risk of fracturing teeth. (However, Monte's dentist says there is less risk than in bite/protection sports. But I'd imagine most of those issues are handler error. It isn't unusual to loose entire canine or fracture the tips off in those events.) Here's an *OK survey regarding the risks of feeding raw: Raw Fit Pet
Within my fairly large circle of raw feeders, we've seen many fractured teeth in dogs that were consistently fed weight bearing bones. Some have debated whether this was due to the dog's diet during development, but generally we don't feel it is worth the risk and the associated expense of a root canal ($1,500) or extraction ($450).
The cooked do splinter, and the weight bearing crack teeth. If you do want to see what happens take a cooked bone and smack it with a meat tenderizer. Then do the same with raw bones.
If you do want to give knuckle bones, have the butcher quarter them and take them away after the marrow and ends are gone. And, always, always, watch your dogs when they are eating bones. Just like with pigs ears, Greenies (Yuck), and hide, weird things DO happen, so keep an eye on the furbabies when they are chowing down. (I worked in an eVet for a while...saw a lotta *weird stuff.)
Raw bones also make for great teeth cleaner and provide great exercise for their necks and jaws. Don't clean too much off that bone!
And a satiated Monte: