What is the Clinical and Cost Effectiveness of Arthroscopic Sub-acromial Decompression Surgery?

The prevalence of shoulder complaints in the UK is estimated to be 14%, with 1-2% of adults consulting their general practitioner annually regarding new-onset shoulder pain. Rotator cuff pathology, including rotator cuff tears and sub-acromial pain, reportedly accounts for up to 70% of shoulder pain problems. Other common causes of shoulder pain include frozen shoulder, calcific tendonitis and osteoarthritis (OA).

Painful shoulders pose a substantial socioeconomic burden. Disability of the shoulder can impair ability to work or perform household tasks and can result in time off work. Shoulder problems account for 2.4% of all general practitioner consultations in the UK and 4.5 million visits to physicians annually in the USA. With the exception of fractures and traumatic rotator cuff tears, most shoulder pain problems are treated initially with conservative care. In some patients with persistent symptoms, surgery might be required. More than 300,000 surgical repairs for rotator cuff pathologies are performed annually in the USA, and the annual financial burden of shoulder pain management in the USA has been estimated to be US$3 billion.

Sub-acromial pain is the most frequent cause of shoulder problems in the general population. An anatomical etiology has been proposed, whereby mechanical contact occurs between the rotator cuff tendons and the overlying acromion and coracohumeral ligament. Sub-acromial pain and rotator cuff tears are associated with progressive change in the shape of the acromion, with 'spurs' forming at its antero-inferior margin. Evidence suggests spurs develop which narrow the sub-acromial space, thereby making physical contact more likely, particularly in certain positions of the arm (for example, painful arc), and resulting in inflammation. This is sometimes referred to as "impingement". However this term suggests a definitive mechanism of the pain and conflicting theories indicate such mechanisms are not definitive. For the purposes of this study we will continue to refer to this as "sub-acromial pain".

A high proportion of patients with sub-acromial pain will respond to conservative treatment. The most frequent indications for surgery are persistent and severe pain combined with functional restrictions that are resistant to conservative measures. Despite surgery being considered at this point, some reports show that surgery can be no more effective than physiotherapy in the relief of pain when used in patients at this stage. Surgical intervention can, however, achieve good results and its judicious use seems valid. The most common surgical intervention for sub-acromial pain is a sub-acromial decompression (SAD), which can be performed through an arthroscopic (ASAD) approach. An assessment of the cost of treatment of impingement also suggested that the addition of surgery, in comparison to exercise treatment alone, is not cost-effective.

Further research might identify whether the source of pain is the tendon, the acromion or the bursa, and hence help to rationalize surgical treatment.