I'm going to have a decompression and debridement surgery for a rotator cuff tear. What kind of restrictions are there after an operation like this?

There may not be any restrictions. Your surgeon will advise you according to what is done in the operating room. Most often patients are limited only by their pain. They are encouraged to use the arm with as much motion as soon as possible.

The reason for this is because with this type of surgery there are no stitches or sutures to be careful of. The healing tissue isn't likely to pull apart. No tendon has been sewn back to the bone.

Debridement is just a cleaning up process. Any fragments of torn tissue are carefully removed. Rough patches are shaved and smoothed. In an acromioplasty, part or all of the bone that comes across the top of the shoulder is taken out. Movement is going to be the best rehab.

You probably won't want to lie on that side. And when you lie down on the other side, it might be helpful to have a pillow under the arm that was operated on. This will help support the healing soft tissues. The physical therapist will probably instruct you in some range of motion and gentle strengthening exercises to get you started.