I cut two, identical looking, osage limbs a few months back. Both were 10-12" in diameter and @76" long. One had little twist but was heavily knotted on the top. The other had @ 90* of twist in it. The twist wasn't visible when I cut it.

I got several good staves out of both limbs. Even a stave with a 60-90* helicopter twist will make a bow and when strung will often straighten out nicely. It's pretty cool seeing people's reactions to a crooked bow that shoots. Unfortunately I have seen more of these than have had time to shape out.