The rotator cuff of the shoulder is a group of four muscles that share a common tendon. The muscles are first attached to different places on the shoulder blade and then to the top of the upper arm (the humerus). Surrounding the tendon is a fluid filled sac that cushions it.
When the tendon and bursa become irritated by repetitive motions, injuries, wear and tear on the shoulder that causes bone spurs or abnormalities of the joint, they swell and become painful.
If this condition is severe, surgery may be needed. This procedure is called a subacromial decompression. It is usually done using minimally invasive techniques - arthroscopic subacrominal decompression.
During the surgery, the inflamed bursa, some of the bone and any spurs are removed to create more space for the rotator cuff tendon to slide through when the arm and shoulder are moved.