Early nerve protection with anterior interosseous nerve in modified end-to-side neurorrhaphy repairs high ulnar nerve injury: a hypothesis of a novel surgical technique.

High ulnar nerve injuries frequently result in poor functional recovery. The prolonged denervation of target muscle largely accounts for the poor functional outcome. There are no approved effective treatments for high ulnar nerve injuries. However, the technique of reverse end-to-side (RETS) offers novel possibilities. The RETS nerve transfer not only provides earlier motor end-plate reinnervation to "babysit" the target muscle until native axons from the original high nerve regenerate, but also augments the regenerating axons. We postulate that coaptation of anterior interosseous nerve to the side of distal ulnar nerve by RETS technique could be an effective therapeutic intervention for high ulnar nerve injuries in human.