The Missus had surgery 13 weeks ago. Partial rotator tear, partial detached bicep muscle, had some bone removed along with calcium deposits.
She came home tethered similar to one of those ice boxes pictured above. A Bregg polar care cube. 72 hours straight in a chair with that thing pumping ice water. Slept a whole week in a recliner.
Doc says she's doing excellent, and the damage was cumulative over some 20 years or more.
the PT folks have her down to once a week. She followed all instructions to the letter, very important.
It was not easy, and in fact, the icing, stretching and light weight lifting will continue for another 3-6 months. Then she decides if she wants the other shoulder done.
Right shoulder done for now, she's left handed. The next one is going to be real tough.
Follow the professionals advice to the latter.
Edit: to Charlie's point, the insurance company denied paying for the cold box but payed for the arm attachment, initially, saying it was "not medically necessary". Huh, How does one device work without the other??? And they sent her home attached to it, it was not optional.
Eventually they paid, it may have been that a wrong code was entered into billing.