Wolverine's claws are coated in adamantium just like his skeleton, but there is no direct adamantium connection between the two - the claws are attached to muscle & tendon, not bone. It seems to me that an opponent with sufficient strength should be able to grab the claws and rip them out of Wolverine's arm completely, severing the muscles and tendons holding them in place.
Has Wolverine ever had his claws ripped out by an opponent?
Note: I am not interested in cases where the claws were broken - only cases where they were actually torn out of the arm by an enemy.