These illustrations are based on the Meyers and McKeever classification system.

• Type 1 - minimally/non-displaced fragment
• Type 2 -  anterior elevation of the fragment
• Type 3 - complete separation of the fragment. 3b - Involves the majority of the eminence. 
• Type 4 - comminuted avulsion or a rotation of the fragment.

I've lightly indicated a type 4 "b" to show a rotational type 4 in contrast to the comminuted type 4. No type 4b has been described in the literature. Both rotated fragments and comminuted avulsions have been referred to as just "type 4."