The use of arthroscopic subacromial decompression has increased dramatically in the United States. Many researchers have suggested that it may not ne needed and, in fact, can be harmful. It was previously thought that “bone spurs” cause rotator cuff tears- based on old cadaver studies in the 1970’s. Studies over the last few decades have shown the rotator cuff degenerates with age as a result of a change in blood supply, leading to fiber breakdown and tear. This process is called impingement syndrome because of the old cadaver studies when it really is not the result on “impingement”. The “spurs” are actually calcification of the coraco-acromial ligament in response to a weak or torn rotator cuff (i.e. the cuff issues cause the spurs not vice-versa). This study is further evidence, that in patients who do not need a rotator cuff repair there is no basis of isolated SUBACROMIAL DECOMPRESSION/ACROMIOPLASTY. Dr. Bailie is currently investigating this as well and his preliminary findings in nearly 100 patients supports this conclusion, except in rare cases where a true spur has developed as a result of a prior surgery. Proper rehab is the key to resolving impingement pain.