If you're talking about PMR, cats can only handle the smaller bones - wings, wing tips etc. This is partly a size thing, and partly a balance thing - you need to be sure of feeding the right ratio of meat to bone. Too much bone will cause constipation
With kittens, I wouldn't advise going bigger than a wingtip. Kittens are only little, and need to learn how to handle meat on the bone in manageable quantities before (when they're older, bigger and stronger) moving onto a full wing.
In terms of feeding ground raw, all bones are fine, so long as the meat to bone ratio in the completed mix is correct [article="32339"][/article] [article="32194"][/article]