I had my wrist pinned a few years back. Admittedly, I wasn't 80, but I have other underlying health conditions. I requested the surgery to be done under a local (block) anaesthetic, something which my surgeon couldn't quite understand, and had to return to the hospital two days later for the proceedure. They kept me in overnight because my arm was totally numb and I couldn't feel where it was or what it was doing, but other than that it was totally successful. Physio started within a couple of weeks, and about 2 months later I was back practicing the (classical) guitar - in a very limited way, admittedly, to start off with - but I had no retriction caused by the surgery. I was told I could drive as soon as I felt I could handle the car in an emergency!! As long as he religiously does the exercises, he should be beck driving fairly soon!!
Just a word of warning: if he has to go through a security check, just let them know he has metal in his arm!!