Subacromial Shoulder Pain

Swipe through the images to learn what subacromial shoulder pain is and what treatment works!

What is it?
If you are suffering from non-traumatic pain around the front or side of the shoulder that is worsened with lifting or overhead movements, you may have subacromial shoulder pain syndrome (SAPS) – a broad term including conditions such as rotator cuff tendinopathy, partial tears, bursitis, biceps tendinitis and calcific tendinitis.

What causes it?
Previously, it was widely thought that one of the main causes of rotator cuff disease was physical impingement of the tendons in the subacromial space of the shoulder – you may have even been told this is the cause of your pain. Researchers today have found very little evidence supporting this theory, and in fact have conflicting evidence such as shoulder decompression surgery to address ‘impingement’ being no better than placebo for rotator cuff disease. While impingement may be one of many smaller contributing factors, it is likely an outdated diagnosis on its own.

Tears in the rotator cuff musculature have also been suggested to be the cause of pain but this is also questionable when we look at the current literature. While likely a contributing factor, researchers have not found a direct relationship between rotator cuff tears and pain – some people have large tears with no pain; others with small tears and intense pain. Furthermore, some patients still report relief from surgical procedures that fail to repair rotator cuff tears. It is estimated that around 23% of the general population have partial or full-thickness rotator cuff tears without pain or loss of function, making asymptomatic tears quite common. However, pain-free rotator cuff tears are rather rare in young patients; with incidence mostly seen from age 50 onward, becoming more common with age.

Current theories suggest that rotator cuff disease is a form of overuse tendinopathy, likely due to a failed healing response – often with little evidence of inflammation.

Risk factors & prevention

While the exact mechanism of pathology is still unclear, risk factors for developing SAPS have been identified:

– Repetitive shoulder, hand & wrist motion
– Heavy or prolonged loading of the shoulder
– Exposure to hand-arm vibration
– Poor ergonomic shoulder posture
– High stress & psychosocial load

Investigations & Imaging
While MRI is the gold standard, it is very expensive. Fortunately, ultrasound has a similar rate of detection of partial and full thickness rotator cuff when compared to MRI – making it the most cost-effective and preferred imaging modality for investigating SAPS.

Which treatments work?
Conservative management including physical therapy, medication and modification of risk factors is the recommended approach for treating SAPS.

Studies report rehab exercise, particularly focused on the rotator cuff and scapular stabilisers, are effective in improving pain and function. Massage also appears to be helpful in SAPS management. Therapeutic ultrasound however may not be better than placebo for this condition.

Oral NSAIDs have shown to be effective in the first 2 weeks when compared to placebo. Corticosteroid injections have shown to be more effective than placebo and physical therapy in the first 8 weeks – though the effect in the long term is unclear (>3 months).

There is currently no convincing evidence that surgical treatment has any benefit over a non-operative approach. Researchers speculate the benefit from surgery is likely due to placebo and post-operative rest and physical therapy. If however conservative care has failed, bursectomy may be considered.

For diagnosis and management of this condition, consult a qualified health professional.

 

Written by: David Resic (Osteopath)

 

Beard D, et al, (2018). Arthroscopic subacromial decompression for subacromial shoulder pain (CSAW); a multicentre, pragmatic, parallel group, placebo-controlled, three-group, randomised surgical trial. Lancet

Dhillon KS, (2019). Subacromial Impingement Syndrome of the Shoulder: A Musculoskeletal Disorder or a Medical Myth?. Malaysian Orthopaedic Journal

Diercks R, et al, (2014). Guideline for diagnosis and treatment of subacromial pain syndrome, a multidisciplinary review by the Dutch Orthopaedic Association. Acta Orthopaedica

Karjalainen T, et al, (2019). Subacromial decompression surgery for rotator cuff disease. Cochrane Database Systematic Reviews

Tempelhof S, Rupp S, Seil R, (1999). Age-related prevalence of rotator cuff tears in asymptomatic shoulders. Journal of Shoulder and Elbow Surgery