Subacromial decompression

Published by Bupa’s Health Information Team, August 2011.

This factsheet is for people who are having subacromial decompression, or who would like information about it.

Subacromial decompression is an operation to prevent the bones and tendons in the shoulder rubbing against each other when the arm is raised.

You will meet the surgeon carrying out your procedure to discuss your care. It may differ from what is described here as it will be designed to meet your individual needs.

About subacromial decompression

The subacromial area is the space between the top of your upper arm bone (humerus) and the small bone attached to the top of your shoulder blade (acromion). As you raise your arm this area narrows. In the area is a small, fluid-filled sac (bursa) and the tendons of the rotator cuff muscles. Certain movements, for example repetitive overhead activities such as golf or repeatedly reaching up to high shelves, can cause irritation and swelling of the bursa and tendons. Bony spurs (a bony growth caused by wear and tear) can also form on the top of your shoulder blade as it rubs against the upper arm.

Bony spurs or a swollen bursa can reduce the amount of space between the shoulder blade and the rotator cuff tendon. This squeezes the tendon as the arm is moved, which can cause pain and restrict your movement. This is called subacromial impingement.

Subacromial decompression opens up this space by removing any swollen or inflamed bursa, changing the shape of your shoulder blade and removing any bony spurs. The operation is usually done as a keyhole procedure using a special telescope (arthroscope) attached to a video camera.

What are the alternatives to subacromial decompression?

For some people, subacromial decompression isn’t necessary. Shoulder pain has various causes and the symptoms can often be managed with self-help treatment, physiotherapy, non-steroidal anti-inflammatory medicines and steroid joint injections. Subacromial decompression is usually only recommended if other treatments haven’t worked for you.

Preparing for subacromial decompression

Your orthopaedic surgeon (a doctor who specialises in bone surgery) will explain how to prepare for your procedure. For example, if you smoke you will be asked to stop, as smoking increases your risk of getting a chest or wound infection, which can slow your recovery

The operation is routinely done as a day case, which means you won’t have to stay overnight in hospital.

Subacromial decompression is usually done under general anaesthesia, which means that you will be asleep during the procedure.

If you're having a general anaesthetic, you will be asked to follow fasting instructions. This means not eating or drinking, typically for about six hours beforehand. However, it’s important to follow your surgeon’s advice.

Your surgeon will discuss with you what will happen before, during and after your procedure, and any pain you might have. This is your opportunity to understand what will happen, and you can help yourself by preparing questions to ask about the risks, benefits and any alternatives to the procedure. This will help you to be informed, so you can give your consent for the procedure to go ahead, which you may be asked to do by signing a consent form.

What happens during subacromial decompression

Subacromial decompression can take up to one hour, depending on how complicated your operation is.

Once the anaesthetic has taken effect, small cuts are made in the skin around your shoulder that is being treated.

Your surgeon will look at the joint, either directly through the arthroscope, or at pictures it sends to a monitor. Specially designed surgical instruments are inserted through the small cuts and are used to reshape your shoulder blade. Your surgeon may also decide to repair any damaged tendons at the same time, such as the rotator cuff tendon. This may mean that your surgeon has to change from keyhole surgery to an open operation, which means making a larger cut in your shoulder (see our common questions for more information).

At the end of the operation, the surgical instruments are removed and the cuts are closed, usually with stitches.

What to expect afterwards

You may need to rest until the effects of the anaesthetic have passed. Your arm may be placed in a sling for a few days after your operation. You may need pain relief to help with any discomfort as the anaesthetic wears off.

You will usually be able to go home when you feel ready. You will need to arrange for someone to drive you home. Try to have a friend or relative stay with you for the first 24 hours after your subacromial decompression.

General anaesthesia temporarily affects your co-ordination and reasoning skills, so you must not drive, drink alcohol, operate machinery or sign legal documents for 24 hours afterwards. If you're in any doubt about driving, contact your motor insurer so that you're aware of their recommendations, and always follow your surgeon’s advice.

The amount of time your dissolvable stitches will take to disappear depends on the type of stitches you have. However, for this procedure, they should usually disappear in about six weeks.

Recovering from subacromial decompression

It usually takes between two and six months to make a full recovery from subacromial decompression, but this varies between individuals, so it's important to follow your surgeon's advice. How long it takes you to recover will depend on a number of things, including how healthy you are before the operation and how well you keep up with your physiotherapy after the operation.

If you need pain relief, you can take over-the-counter painkillers such as paracetamol or ibuprofen. Always read the patient information leaflet that comes with the medicine and if you have any questions, ask your pharmacist for advice.

It’s important that you continue with any exercises recommended by your physiotherapist (a health professional who specialises in maintaining and improving movement and mobility) or surgeon, as these may help you to recover more quickly. Your surgeon or physiotherapist will decide on the type of exercises that you will need to do. He or she will also tell you when you should start these exercises, and how many you should do.

What are the risks?

As with every procedure, there are some risks associated with subacromial decompression. We have not included the chance of these happening as they are specific to you and differ for every person. Ask your surgeon to explain how these risks apply to you.


Side-effects are the unwanted but mostly temporary effects you may get after having the procedure.

You may have some pain and stiffness around your shoulder after surgery. This may make moving around uncomfortable at first.

If you develop any of the following symptoms, contact your hospital immediately as they may indicate you have an infection.

  • The wound becomes hot, red or swollen.
  • The wound bleeds or becomes more painful.
  • You have a high temperature.


Complications are when problems occur during or after the operation.

The possible complications of any operation include an unexpected reaction to the anaesthetic, excessive bleeding or developing a blood clot, usually in a vein in the leg (deep vein thrombosis, DVT).

One of the possible complications of subacromial decompression is accidental damage to the shoulder blade or another part of the shoulder joint, including nerves or blood vessels. If the nerves are damaged during subacromial decompression, this may lead to a loss of feeling over the shoulder. However, this is rare. It’s also possible for the upper edge of the shoulder blade (acromion) to fracture after surgery.


For answers to frequently asked questions on this topic, see Common questions.

For sources and links to further information, see Resources.

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  • This information was published by Bupa's Health Information Team and is based on reputable sources of medical evidence. It has been reviewed by appropriate medical or clinical professionals. Photos are only for illustrative purposes and do not reflect every presentation of a condition. The content is intended only for general information and does not replace the need for personal advice from a qualified health professional. For more details on how we produce our content and its sources, visit the about our health information page.

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  • Publication date: August 2011