Torn Rotator Cuff?

[Blueface]

I have had a slight tear on each of my rotator cuffs. Fortunately, not at the same time.
Both tears confirmed via MRI.
Saw dr's for surgery both times.
Both dr's told me the same thing, may or may not improve.

Instead of surgery, I did the same with the second tear since it worked so well for the first.
I did physical therapy and lots of it at home, on my own, with a towel while in the shower.
I used the towel and my good arm to aid the hurting one stretch gradually every day.

I ended up being fine. I still have an occasional flare up but the major pain is long gone.
No surgery done and glad I went this route.

In your case, 50% tear sounds way more than what I had.