Herb, I studied a soldier who has 29 pages of military records from NARA and several other sources, some family lore. He was wounded in one arm at Sharpsburg, spend some time in a field hospital and then returned home to convalesce in Texas until January. He was an officer in the 1st TX, ANV, so while his unit was decimated, he was allowed to take plenty of time to recuperate...perhaps so he might recruit some more badly needed soldiers.

Are you certain that your ancestor returned to service 19 days after his wound? Even if he showed up on the next muster roll, I would be skeptical if the wound was severe. I do not recall any soldiers returning to duty after an amputation unless they were high ranking officers, like John Bell Hood, who had aides to assist them. Perhaps there were other maimed officers who took garrison or prison duty like Captain Wirz.