Subacromial decompression

Subacromial decompression is an operation on your shoulder to treat a condition called shoulder impingement, which causes pain when you lift your arm. It’s usually done through keyhole surgery (arthroscopy). The operation is sometimes called acromioplasty.

Why do I need subacromial decompression?

Subacromial decompression used to be a popular surgery for shoulder impingement. It’s no longer recommended for most people with shoulder pain, as rest and physiotherapy usually ease the symptoms instead. But some people do still need subacromial decompression if these other treatments aren’t working.

What is shoulder impingement?

Shoulder impingement is a common type of shoulder pain.

A group of muscles called the 'rotor cuff' surround and support your shoulder. These help you to lift your arm up so you can reach for things above you. The tendons for these muscles lie in a narrow space between the top of your arm bone and the bone at the top of your shoulder blade.

Shoulder impingement happens if lifting your arm puts too much pressure on the tendons. When the tendons press against the shoulder blade above them, this causes pain. You may also find it harder to move your arm.

Shoulder impingement has lots of different causes. These include:

• your tendons getting swollen or torn from overuse (if you’re doing a lot of sports) or ‘wear and tear’ as you get older
• the shape of the bone at the top of your shoulder blade (your acromion), which rubs against your tendons
• getting bony growths (spurs) on your acromion as you get older

Subacromial decompression surgery smooths down the surface of your acromion so it doesn’t rub against your tendons. This helps to ease your pain.

Preparing for subacromial decompression

Your operation will be done by an orthopaedic surgeon (a doctor who specialises in bone surgery). They’ll explain how to prepare for your procedure. If you smoke, you’ll be asked to stop. This is because smoking makes you more likely to get a chest or wound infection, which can slow down your recovery.

Before you go into hospital, you’ll need to prepare for after your surgery. The operation’s usually a day-case procedure, which means you can go home on the same day. You’ll need to arrange for someone to collect you from hospital after your surgery and take you home. And you’ll need to make plans for someone to be with you for at least the first day after you come home.

You’ll probably be having a general anaesthetic, so you’ll be asked to follow fasting instructions. This means not eating or drinking for several hours before your surgery. Follow your anaesthetist or surgeon’s advice carefully.

Your surgeon will discuss with you what will happen before, during and after your surgery. If you’re unsure about anything, don’t be afraid to ask. No question is too small. It’s important that you feel fully informed, so that you feel happy to give your consent for the operation to go ahead. You will be asked to do this by signing a consent form.

What are the alternatives to subacromial decompression?

Shoulder impingement symptoms can often be eased with:

• self-help treatment, including rest and avoiding painful movements
• painkillers (such as paracetamol or non-steroid anti-inflammatory medicines )
• physiotherapy
• steroid injections

Your surgeon will usually only recommend you have subacromial decompression if other treatments haven’t worked. You can ask your surgeon to explain why they feel it’s the best option for you.

What happens during subacromial decompression?

During a subacromial decompression procedure, your surgeon will aim to make more space under your acromion so it doesn’t press against your tendons. To do this, they’ll take away some of the bone and tissue.

Subacromial decompression is usually done as a keyhole procedure. It uses a narrow, flexible, tube-like telescopic camera called an arthroscope. It’s usually done under general anaesthesia, which means you’ll be asleep during the procedure. You may also be given a local anaesthetic into the nerves around your shoulder. This helps to ease any pain you may feel after your operation.

Your surgeon will put the arthroscope into your shoulder through small cuts in your skin and then look inside your shoulder. They’ll insert specially designed surgical instruments to carry out the subacromial decompression procedure. Your surgeon may also decide to repair any damaged tendons at the same time. This may mean they have to change from keyhole surgery to an open operation and will make a larger cut in your shoulder.

At the end of the operation, your surgeon will remove the surgical instruments and close the cuts, usually with stitches.

What to expect after a subacromial decompression?

You’ll need to rest until the effects of the anaesthetic have worn off. Let your Doctor know if you’re in pain. You’ll be offered pain relief to help with any discomfort as the anaesthetic wears off.

You’ll usually be able to go home when you feel ready. Someone else should drive you home. Try to have a friend or relative stay with you for the first 24 hours.

Having general anaesthesia can affect your co-ordination and reasoning skills for a short time. So, don’t drive, drink alcohol, operate machinery or sign legal documents for 24 hours afterwards. Always follow your surgeon’s advice.

Before you leave hospital, your nurse will give you advice about caring for your wounds and tell you what to do about any stitches you have. Your stitches may be taken out after 10 to 14 days. You may need to keep your arm in a sling for up to three weeks after your operation.

Your shoulder joint is likely to feel sore and stiff for a while. Using a cold compress, such as an ice pack or a bag of frozen peas wrapped in a towel may help to reduce swelling. But don’t put ice directly onto your bare shoulder because it can damage your skin.

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. If you have any questions, ask your pharmacist.

Recovering from subacromial decompression

It usually takes three to six months to fully recover from a subacromial decompression procedure. You’ll probably need help to wash and dress yourself at first. This should get easier after a few weeks.

You’ll usually need to take a few weeks off work after your surgery, depending on your job. You may need to avoid heavy lifting for around three weeks and avoid anything that involves reaching above your head for around three months. Follow your surgeon’s advice on going back to work and getting back to your usual activities.

You’ll usually see a physiotherapist after your operation. It’s really important that you do any exercises that your physiotherapist or surgeon recommends. These may help to stop your shoulder getting stiff. You’ll have exercises to do at home and you may also be offered a few sessions with a physiotherapist. These exercises may:

• stretch the muscles around your shoulder
• help you move your shoulder more easily
• make the muscles around your shoulder stronger

You’ll usually be advised to keep doing exercises for three to six months after your surgery.

Side-effects of subacromial decompression

You may have some side-effects after subacromial decompression. 

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

If you get any of the following symptoms, contact your hospital immediately because this may mean that you have an infection or other complication.

• Your wound gets hot, red or swollen.
• Your wound bleeds or feels more sore.
• You have a high temperature (fever).

Complications of subacromial decompression

Like all types of surgery, subacromial decompression can cause some complications. These include:

• an unexpected reaction to the anaesthetic
• a blood clot in the veins of your leg ( deep vein thrombosis – DVT)
• a lot of bleeding (a haemorrhage)
• an infection

Other possible complications include:

• accidental damage to the tissues around your shoulder joint, including nerves or blood vessels
• stiffness in your shoulder (a ) – this usually gets better after three to six months

Ask your surgeon about possible complications and how likely they are to affect you.