Steroid Injections for Shoulder Impingement
Shoulder impingement is an “umbrella term” used to describe a range of conditions that can cause pain on the outside of the arm. The true diagnosis can be a
- rotator cuff tear
- rotator cuff tendinopathy
- Or a combination of the above with other joint involvement like the acromioclavicular joint.
Symptoms of Shoulder Impingement
The most common symptoms of shoulder impingement are:
- Pain as you raise your arm to the side (often this is in a specific range of motion that we call an “arc of impingement”).
- Pain reaching above your head
- Pain reaching into a jacket or reaching behind the back
- Pain lying on the side in bed which can wake you overnight
Shoulder Joint Anatomy
The shoulder is a ball and socket joint made up of the humerus (upper arm bone) and the scapular (shoulder blade). The socket on the scapula, know as the glenoid fossa, is not very big or deep which then requires additional support to prevent the shoulder becoming unstable. This anatomy however allows for a greater degree of motion that we utilise compared to other joints. To improve joint stability there is a ring of gristle around the socket known as the glenoid labrum. This essentially increases the socket size and contact for the humerus bone in the glenoid fossa. The other main stabilising structures are the rotator cuff muscles. This is a group of 4 muscles that provide stability to keep ball in the socket. When there is an imbalance of these muscles, the arm bone may move excessively in one direction which may in turn cause a shoulder injury, subluxation or dislocation.
On top of the scapular is a bony prominence called the acromion. This sits over top of the joint like a roof. As we raise our arm up, the humerus bone and the acromion bone begin to approximate and it is essential that all the structures slide out of the way so they do not get pinched. This is achieved but the scapular rotating and the rotator cuff muscles gliding the humerus bone in the right arc. If something goes wrong with this delicate balance then something may become pinched which can be the start of an impingement syndrome.
The other joint commonly associated with shoulder impingement is the acromioclavicular joint. This is a small joint more medially which joins the shoulder blade to the chest wall via the clavicle (collar bone). Shoulder impingement may also include a dysfunction at this joint and more can be read about acromioclavicular joint injuries here.
To work out what structure is causing shoulder impingement we usually need to carry out a diagnostic ultrasound scan or MRI.
This refers to inflammation of the subacromial subdeltoid bursa which is a fluid filled sack sitting in a small space on top of the shoulder. If this bursa becomes inflamed and swells, then it gets pinched as you raise your arm. Once it pitches again, then its more likely to swell and the cycle of impingement continues.
Rotator cuff injuries
The most commonly affected rotator cuff muscle is the supraspinatus. Its location on top of the shoulder puts it in the most likely place to cause an impingement. If the tendon becomes overloaded and damage occurs, it can swell or tear which will then cause impingement when raising the arm.
It is essential we get your diagnosis right so that we can manage your shoulder pain effectively.
How to diagnose
One of our highly skilled Physiotherapists will ask a series of questions and perform a physical examination to help develop a diagnosis. Here at Oxford Circus physiotherapy we can also use diagnostic ultrasound to check the grade of the injury and stability of the joint. Using the diagnostic ultrasound also allows the clinician to assess the shoulder joint dynamically throughout painful arm movements. If we require further clarification, then occasionally we need to order an MRI scan.
In general, shoulder impingement can be well managed with conservative Physiotherapy treatment and not require surgical intervention.
Symptoms usually resolve within 1 year. However, if you want to get better faster then we can also:
- Prescribe a course of physiotherapy to restore range of movement, strength and function of the rotator cuff and scapular stabilising muscles.
- You can try over the counter anti-inflammatories if there is a bursitis present.
- Short period of rest from aggravating factors – particularly lying on that shoulder and overhead activities. It is important to avoid aggravating activities for at least 6 weeks as returning to certain activities too soon can cause further injury.
- Prescribe Shockwave treatment if you have calcific tendinopathy of the rotator cuff
Physiotherapy may include:
- Independent exercise program to strengthen the stabilising muscles of the shoulder joint and surrounding muscles.
- Advice on appropriate load management and a gradual return to activity plan
- Manual techniques including soft tissue release to provide relief and help restore full range of movement.
- Ergonomic and postural advice.
Ultrasound guided corticosteroid injection
Shoulder Impingement Ultrasound guided corticosteroid injection
If symptoms have not improved after 6 weeks of physiotherapy, or if the pain is affecting your sleep, stopping you from performing everyday activities such as getting dressed or is limiting you from performing your physiotherapy exercises you may want to consider an ultrasound guided steroid injection.
Steroid injections use a small dose of corticosteroid (a strong anti-inflammatory drug) and are injected under ultrasound-guidance into the subacromial subdeltoid bursa. Current evidence found that injections performed under ultrasound guidance are more accurate and more effective at reducing pain and improving function than landmark guided injections (Daniels et al, 2018).
Daniels, E.W., Cole, D., Jacobs, B. and Phillips, S.F., 2018. Existing Evidence on Ultrasound-Guided Injections in Sports Medicine. Los Angeles, CA: SAGE Publications.
Mall, N.A., Foley, E., Chalmers, P.N., Cole, B.J., Romeo, A.A. and Bach Jr, B.R., 2013. Degenerative joint disease of the acromioclavicular joint: a review. The American journal of sports medicine, 41(11), pp.2684-2692.