Ted,
So sorry to learn that you will need surgery for your hand.
During the surgery, it may depend on the time required for the surgery. If lengthy, you may find yourself to be catheterized with a Foley catheter when you wake up. If you can wear a condom catheter that is another option.
You asked how we handled "the situation" after surgery. In my case I would say poorly, despite my best efforts. After shoulder surgery it was nearly impossible to put on a tabbed diaper by myself, one-handed.

However, I knew that pull-ups just would not be effective enough. So, my wife helped and we put on and pre-fitted a supply of tabbed diapers, but fastening only three of the four tapes. That way, later, I could pull up the diaper like a pullup, but then adjust the remaining tape for a reasonably good fit. I was very self-conscious if not embarrassed for my wife to have to put my diaper on "up close and personal" while I leaned against a wall to hold the back of the diaper up. I also was extremely appreciative for her support.
Another story is how to self-administer my daily preventive enemas for my fecal incontinence one-handed, but that story is best left for another time.
--John