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Shoulder joint pain, man with severe ache as symptom of osteoarthritis, close up with sele

Impingement/Sub-Acromial Pain Syndrome


Impingement or Sub-Acromial Pain Syndrome is the most common cause of self- limiting shoulder pain. In simple terms your rotator cuff  tendon inside your shoulder rubs or catches on nearby tissue and bone as you lift your arm. 



Impingement or Sub-Acromial Pain Syndrome is the most common cause of self- limiting shoulder pain. In simple terms your rotator cuff  tendon inside your shoulder rubs or catches on nearby tissue and bone as you lift your arm. 

Your rotator cuff is important for the movement of your shoulders, in particular the 'Supraspinatus tendon' which helps you to raise your arm. This tendon attaches on the top of you humerus 'Ball of the shoulder joint' (Illustrated on the left) through a channel called' the sub-acromial space'.

This space contains tiny, slippery sacs of fluid called 'bursae' facilitate this gliding motion by providing a thin cushion and reducing friction between the surfaces.

Both the Bursa 'Bursitis' and the tendon ' Tendonitis' can become 'inflamed' or irritated causing pain.

In some instances the bony surface ' Acromium' which forms the roof of the channel (Sub-acromial space) can rub against the tendon causing pain when lifting your arm. The inflammation may give you night time pain and difficulty reaching for things due to sudden pain or a ' catching' sensation.


Anyone can suffer with shoulder impingement at any age. It is much common in younger people and generally occurs after repetitive or intense activity (Overuse injury). Shoulder impingement syndrome is thought to be the cause of 44% to 65% of all shoulder pain complaints.


Arthroscopic surgery to shoulder or Knee surgery.jpg


Shoulder impingement is diagnosed clinically (by asking you about your symptoms and examining your shoulder) either by your GP, an experienced Physiotherapist or your Shoulder surgeon.  

Classically you will have pain on raising your arms sideways to 90 degrees. You may also have pain putting your arms behind your back. 


Universally the first line treatment after a correct diagnosis has been made is non- operative with physiotherapy, pain killers and a cortisone (Steroid injection)  into the sub-acromial space/ bursa. This is normally given from the back of  your shoulder and will reduce the inflammation and pain so that you can do your physiotherapy exercises.

In relation to  your physiotherapy it is important that your therapist works to strengthen your rotator cuff, treat any post capsular tightness, treats muscle trigger points especially around the trapezius and addresses poor scapula position. To address all these does take time and perseverance.

Surgery is only considered in small proportion of patients who's symptoms fail to improve after a minimum of  at least 3-4 months of treatment.

The procedure to help treat persistent shoulder impingement is an arthroscopic  (Key hole) sub-acromial decompression. In simple terms this means using a camera and a shaver to clear the inflammation and space above the rotator cuff tendon i.e. the 'sub-acromial space' . If you have bony spurs present these are also removed to prevent it from rubbing on the tendon.



The decision to undergo an arthroscopic  sub-acromial decompression is yours and my duty as your surgeon is to help guide you. My general guidance to patients is that surgery is reserved when all other treatments have failed.

The procedure itself  is not complex but its benefit has been questioned. Large Studies have shown no 'clinically important differences' in patient outcome scores between patients who received physiotherapy alone versus surgery versus placebo at 1 year. Patients in all groups demonstrated clinically important improvement in scores by 6 months. 

Why do you still offer a Sub-acromial decompression if the evidence for it is weak?

Surgery is only considered if you have failed to improve with non- operative treatment measures which includes at least one cortisone/ steroid injection, physiotherapy and pain killers.

Generally if your symptoms disturb your sleep, interfere with self-care tasks, affect you at work or keeping fit then it would be reasonable for surgery to be considered. 

In such cases a sub-acromial decompression may help reduce the pain and allow re-engagement with physiotherapy which is essential for improvement.

It is vital that you fully understand the benefits and risks which are outlined below.

  • Persistent/ recurrent symptoms 

  • Stiffness/ frozen shoulder (1-2%)

  • Infection (<1%)

  • Nerve/ Vessel injury (<1%)

 General anaesthesia is very safe but still carries a small risk (<1%) of Heart Attack, Stroke, Deep Vein Thrombosis, Pulmonary embolism. It is important to have all details of your medications and past medical history so you can be optimised for surgery and these risks can be assessed individually..


Useful external patient info links:

How long do I wear a polysling after my operation?

You should wean your self off the polyling after 48 hours and ideally discontinued by 7 days. Pendular exercised will be shown to you and these should start as soon as pain allows.

Is it normal for my shoulder to be swollen & wound to leak fluid?

You will notice that after surgery that your shoulder has a bulky padded dressing. This is designed to absorb excess fluid from the arthroscopy (Saline is pumped into your shoulder to allow visualisation) for 24 hours and then can be taken off. Your shoulder will appear swollen which is very normal and this will reduce over a few days. Leaking fluid from your key hole wounds will be blood tinged but not frank blood. 

Can I get my dressings wet?

For the first 7 days you must keep your dressings/ wounds dry. 

When Can I start driving?

It  is  illegal  to drive while wearing  a sling.  You may  start  to drive once  the sling  has  been discarded  but  not  until  you can safely  control  the vehicle.  This  is  normally  between 1- 2  weeks  after  the operation.  It  is  advisable to start  with short  journeys.

When can I go back to work?

This  will  depend on the  type of  work  you do  and the  extent  of  the surgery.  If  you have a non-manual job and do not need to drive you may  be  able  to return within 2 weeks.  If  you have a heavy  lifting  job or  one with sustained  overhead arm  movement  you may  require  6 or more weeks off.  

How am I Likely to progress?

It is important to recognise that improvement is slow and that this is not a quick fix operation. By 3 weeks after operation you will not have noticed much improvement. However, you should have recovered nearly full movement. Getting your hand up your back usually takes a little longer. By 3 months after the operation most people have noticed improvement in their symptoms. Everything continues to improve slowly and by 9 to 12 months after the operation your shoulder should be back to normal / feeling like the other shoulder. 

When can I resume heavy lifting/ recreational activities?


 Timings for returning to functional activities are approximate and will differ depending upon the individual. However, the earliest that these activities may commence are:

• Lifting: as able

Swimming: breaststroke: from 6 weeks; front crawl: when able

• Golf: 8 weeks (but not driving range)

• Contact sports: sport specific training when comfortable. Competitive play when able.

Shoulder pain Exercise videos for patients(British Elbow & Shoulder Society)for patients 

Posterior capsular tightness stretches (Athlean X)

Post operative physiotherapy guidelines (RBH)

CSAW Trial  

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