A procedure known as a subacromial decompression (where the underside of the acromion is shaved away to allow more space for the tendons of the rotator cuff) has been found to be both ineffective and in many cases unnecessary.
The study, by a physiotherapist from Chelsea and Westminster Hospital Trust, found no increased benefit from surgery when compared to exercise alone. Exercise also carries fewer risks and is significantly more cost effective.
Plus you don’t get cut with a knife which I tend to avoid where possible.