I had a major rebuild of my right shoulder about 4 years ago: tendon re-attached, rotator cuff repair, pinched nerve,many bone spurs removed--five hours of cut-and-paste After years of pain and increasingly limited motion, I got about 90% function back in three months. Let PT be your new religion!
I started shooting a .410 with skeet loads after that and quickly went back to light loads in my 12s and 20s (I seldom shoot heavy loads any more, I shot a couple of 3" in my Gold Label and that was enough of THAT!).
So far no recurrence of pain, but I avoid .45-70s and upward. But then, we don't have any loose bison around here....