I have shoulder problems for one to two years following a bike accident. Nothing is broken but it is sore.
My solutions were:
Raised the bars to put less weight on my arms. That made a big difference but did not help aerodynamics.
Installed aero bars and use them whenever I am in a hurry, which is most of the time.
The resting on the elbows seems to not irritate my shoulder. I have done centuries that way.

Perhaps this will give you some ideas. I have little faith in MD's and try everything else first. Too many false positives in my and my families past.