Sub-Acromial Shoulder Pain: A Well Overdue Update
The State of Play
Shoulder pain is the third most common musculoskeletal condition, behind neck and back pain. What is worrying about shoulder pain, is that 40-50% of new shoulder pain presentations continue to have symptoms 6-12 months after original onset! You can basically flip a coin to predict whether someone will continue on with a chronic shoulder condition or not.
A recent study by Imagama et al. 2019 found that shoulder pain was more impactful on physical and mental quality of life than knee and lower back pain.
How has it come to this?
Words Matter
If you have ever experienced garden variety shoulder pain in the front or outside shoulder (without significant trauma, massive tear or joint stiffness) and sought advice from a Physio, GP, or specialist, you were probably provided with information that could be doing more harm than good.
Often, a practitioner will explain that there is impingement of tendon/bursa between the bones of the shoulder blade and the upper edge of the socket.
This term was coined over 50 years ago by Neer, an orthopaedic surgeon who said that 95% of rotator cuff tears are caused by impingement giving rise to the sub-acromial decompression surgery which has now been deemed no better than placebo surgery (Cochrane review from 2019).
Using explanations of this nature can be very damaging for a person with sub-acromial shoulder pain. It sets up an expectation that there is something structurally wrong with a person’s shoulder. This type of language and mindset about a painful shoulder can cause fear of movement and sets up a person to fail physiotherapy because of low expectations and self-efficacy.
I am ready to admit that I have used the term ‘impingement’ and the structural explanations that go with it earlier in my career before very timely research came out. Unfortunately, research takes time to become common practice but with the amount of people suffering from chronic shoulder issues, it’s time to change the narrative.
A Good Plan to Scan?
GP’s in Australia have referred shoulder pain patients for imaging at increasing rates. From 20% in the year 2000 to 55% today! Let’s see if scans are useful;
A couple of studies have followed people after they had a rotator cuff repair surgery and performed imaging 10-16 years later. They found that between 37- 50% of people had re-ruptured their repairs but their shoulder function was no different to those with the repair still intact. This helps to question the absolute importance of structure.
Another study looked at using ultrasound imaging on people without shoulder symptoms and found that 96% of people had pathological findings including bursitis, rotator cuff tendinosis, and osteoarthritis of the AC joint.
From a sporting perspective, a large group of young American college baseballers without pain received imaging on their throwing arm. In 47% of them, articular rotator cuff tears were found but they were still able to throw at 150km/hour!
Similar to structural language impacting people’s expectations and belief in recovery, so can imaging report findings. Thankfully there is overwhelming evidence suggesting that we can hold off on the imaging, especially for gradual onset shoulder pain. It gives us even more reason to treat the person, not the scan.
Have a go at an Injection?
Along with imaging, Australian GP’s have also increased the referral for corticosteroid injections for shoulder pain from 10% twenty years ago to 20% today.
A recent review of the evidence of the short versus long-term effects of corticosteroid use for the rotator cuff in shoulders has found a possible short-term benefit but no long-term benefit. Interestingly, in the same review of other body areas such as the knee ,elbow and hip found there was evidence of long-term harm. Learn more about corticosteroid injections and whether they will help your injury.
Studies comparing corticosteroid injection versus active rehabilitation for musculoskeletal pain found that the injection was superior in the first 6 weeks, at 12 weeks the injection was worse or equal to the active rehabilitation and at 6 months and beyond the active interventions were more beneficial.
With the above evidence in mind, we should be far more selective and cautious in the choice to use steroid injections for basic shoulder pain presentations. There can be a time and a place for injections but rarely as a first-choice intervention.
A New Dawn
So, with the excessive referral of steroid injections and imaging for non-traumatic shoulder pain from GP’s, how many shoulder cases are referred for physiotherapy? A measly 12%! This is actually against the best practice guidelines. So, what does best practice management of sub-acromial shoulder pain look like?
Change the label: The old diagnosis needs to change to either sub-acromial shoulder pain or rotator cuff related shoulder pain.
Change the explanation: shoulder pain occurs because an individual does not have the capacity to tolerate the load placed on the shoulder in a given period. Capacity is made up of more than the structure and physical, it is multi-dimensional. Emotional, cognitive, behavioural, biochemical, genetic, and lifestyle factors all play a role.
If there was no trauma, wait for it to turn the corner with exercise modification, avoid unnecessary interventions (injections, surgery, imaging), and trust the process.
Important to screen for low expectations, low self-efficacy and fear of movement as they can impact outcomes.
Person-centered goal setting for what they really need and want to perform.
Management consisting primarily of up to date education, load management, a graded shoulder exercise/strengthening program, and a return to function/sport component for a minimum of 3-12 months.
