Spine in most places is considered its own specialty. The vast majority of hospitals will only grant privileges to those who are ortho spine fellowship trained or NSGY trained with evidence of a certain number of spine cases done in training or in practice.
For hand, most places are the same as above needing fellowship training but not as strict as the “core ortho privileges” often include hand procedures. So some trauma orthos dabble in hand traumas. Most of the places I’ve trained or worked at have hand call separate from the the trauma call.
with that being said, “trauma/fracture” surgeries are done/can be done by regular orthos. The ortho trauma specialists are mostly at the level 1 or referral centers. The ortho trauma docs who don’t work at the referral centers and are in PP do trauma but supplement their practices with joints etc…