I'm sure you have good advice from doctors in your area, so take this for what it's worth. I broke my left leg - fib and tib completely, no puncture of flesh - in 1977. This happened a quarter mile from the UW hospital. Turns out that was fortuitous as the head of the orthopedic dept. at the time was a world expert on compartment syndrome and use of fasciotomy to relieve pressure and prevent amputation. I had a very good recovery from the accident.
I learned years later of his reputation in that field. I did a web search on him a few years ago, turns out he specialized later in shoulder issues. Might be some good perspective to be had:
Frederick A. Matsen III.
His blog:
Shoulder Arthritis / Rotator Cuff Tears: causes of shoulder pain
This video might no be fully current (2013), interesting viewing, incluces video of a surgery:
https://www.youtube.com/watch?v=zF08eYbzYXU