Wasn’t aware he hurt his other hand, @doschicos. He had a second procedure on is injured hand to unblock a nerve impingement, explained here https://cdanews.com/2015/12/jimmy-fallon-explains-newly-bandaged-wrist/
But watching is hand movements, he still seems to posture his hand with his pinky curled under and his injured/ring finger seems to have limited range of motion too. That is so sad. His musical imitations were fabulous.