Orthopaedic Procedures | Subacromial Decompression

About the Shoulder

 

The shoulder is a ball and socket joint with a ligament above it forming an arch. The ligament attaches to bony prominences (the 'acromion' and 'coracoid') on your shoulder blade. The area between the shoulder joint and the arch is known as the "Sub-acromial space".

 

The shoulder joint is surrounded by a deep layer of tendons (the rotator cuff) which pass under the arch. One of these tendons (supraspinatus) commonly becomes worn and painful. It may swell and rub on the bone and ligament above. The bone then may respond to the rubbing and form a spur.

 

 

 

Certain movements of the arm reduce the space under the arch. This is when you use or move your arm at shoulder height. See diagram below.

 

The rubbing causes further swelling of the tendon on the acromion bone. This is a vicious circle.

 

If the cycle of rubbing and swelling is not broken by time, rest, physiotherapy and cortisone injections, then surgery may be necessary. See diagram below.

 

 

About the sub-acromial decompression

 

The operation is done by keyhole surgery ('arthroscopy'). Sub-acromial decompression involves releasing the ligament from the front of the acromion and trimming off the under surface of the acromion bone. (See diagram below.) This allows the tendon to move more freely and thus break the cycle of rubbing and swelling. Success following this operation depends upon the ability of the muscle to heal and resume normal activity.

 

Occasionally the joint involving the outside of your collar bone meeting your shoulder blade can become arthritic. The pain arising from this joint can also be reduced during this keyhole surgery. Please ask your surgeon for the details.


What are the risks?

 

All operations involve an element of risk. We do not wish to over-emphasise them but feel that you should be aware of them before and after your operation. The risks include:

 

  • Complications relating to the anaesthetic such as sickness, nausea or rarely cardiac, respiratory or neurological. (Less than 1% each, i.e. less than one person out of one hundred)
  • Infection. These are usually superficial wound problems. Occasionally deep infection may occur many months after the operation. (Less than 1%)
    Persistent pain and/or stiffness in/around the shoulder. 5-20% of patients will still have symptoms after the operation.
  • Damage to the nerves and blood vessels around the shoulder. (Less than 1%)
    Need to re-do the surgery is rare. In less than 5% of cases, further surgery is needed within 10 years.

 

Please discuss these issues with the doctors if you would like further information.
Questions that we are often asked


Will it be painful?

 

Although you will only have two or three small scars, this procedure can be painful due to the surgery performed inside your shoulder.

 

Before the operation you may be given a nerve block to reduce pain following surgery. An injection of local anaesthetic is given around the nerves in your shoulder. This usually means that you will not have any feeling or movement in your arm when you awake from the anaesthetic. This may last several hours. When you begin to feel the sensation returning (often a 'pins and needles' feeling), you should start taking the pain medication that you have been given. It is recommended that you take pain medication before full sensation returns. Use medication regularly to begin with, to keep the pain under control. If you require further medication, please visit your General Practitioner (GP). You should take great care of your arm whilst it is numb. You could injure it without being able to feel it. Keep your arm away from sources of heat and cold.

 

The other common method to reduce pain after surgery involves infiltrating the operated area with local anaesthetic. The effects of this start to wear off a few hours after the operation. Painkillers will then have to be taken.


Do I need to wear a sling?

 

The sling is for comfort only. You can take it on and off as you wish. You do not need to have your arm strapped to your body. Normally the sling is discarded after a few weeks.

 

You may find it helpful to wear the sling at night (with or without the body strap) for the first few nights, particularly if you tend to lie on your side. Alternatively you can rest your arm on pillows placed in front of you. If you are lying on your back to sleep you may find placing a thin pillow or small rolled towel under your upper arm will be comfortable.

 

 

 

 

Do I need to do exercises?

 

Yes! You will be shown exercises by the physiotherapist prior to your discharge from the ward and you will need to continue with the exercises once you go home. They aim to stop your shoulder getting stiff and to strengthen the muscles around your shoulder. The early exercises are shown at the back of this booklet.

 

Usually an outpatient appointment for physiotherapy will be arranged for you in 2-3 weeks time, but it may be earlier than this if your shoulder is stiff. This delay allows the discomfort from the operation to reduce and the healing process to be well under way.


What do I do about the wound?

 

You will usually not have any stitches, only small sticking plaster strips over two small wounds. Keep the wounds dry until they are healed, which is normally within 5-7 days. Usually the dressings will be removed at between 10-14 days by the district nurse or a nurse at your G.P. surgery. You will need to make an appointment at the surgery to have this done. You can wash or shower and use ice packs, but protect the wounds with cling film or a plastic bag.


Avoid using spray deodorant, talcum powder or perfumes near or on the wounds until they are well healed.

 

When do I return to the outpatient clinic?

 

This is usually arranged for approximately 6 weeks after your operation to check on your progress. Please discuss any queries or worries you may have when you are at the clinic. Further clinic appointments are made after this as necessary.


Are there things that I should avoid?

 

  • There are no restrictions (other than the pain) to movement in any direction. Do not be frightened to start moving the arm as much as you can. Gradually the movements will become less painful.
  • Avoid heavy lifting for 2-3 weeks.
  • Be aware that activities at or above shoulder height stress the area that has been operated on. Do not do these activities unnecessarily. Try and keep your arm out of positions which increase the pain.

 

How am I likely to progress?

 

The discomfort from the operation will gradually lessen over the first few weeks. You should be able to move your arm comfortably below shoulder height by 2-4 weeks and above shoulder height by 6 weeks.

 

Normally the operation is done to relieve pain from your shoulder and this usually happens within 6 months (80%-90% of patients). However, there may be improvements for up to 1 year.


When can I return to work?

 

This will depend on the type of work you do and the extent of the surgery. If you have a job involving arm movements close to your body you may be able to return within a week. Most people return within a month of the operation but if you have a heavy lifting job or one with sustained overhead arm movements you may require a longer period of rehabilitation. Please discuss this further with the doctors or physiotherapist if you feel unsure.


When can I participate in my leisure activities?

 

Your ability to start these activities will be dependent on pain, range of movement and strength that you have in your shoulder. Nothing is forbidden, but it is best to start with short sessions involving little effort and then gradually increase the effort or time for the activity. However, be aware that sustained or powerful overhead movements (e.g. trimming a hedge, some DIY, racket sports etc.) will put stress on the sub-acromial area and may take longer to become comfortable.


When can I drive?

 

You can drive as soon as you feel able. This normally is within a week or two. Check you can manage all the controls and it is advisable to start with short journeys.

 

In addition check your insurance policy. You may need to inform the insurance company of your operation.


Exercises

 

Use pain-killers and/or ice packs to reduce the pain before you exercise, if necessary.

 

Do short, frequent sessions (e.g. 5-10 minutes, 4 times a day) rather than one long session.

 

It is normal for you to feel aching, discomfort or stretching sensations when doing thes exercises. However intense and lasting pain (e.g. more than 30 minutes) is an indication to change the exercise by doing it less forcefully or less often.

 

Continue to do these exercises until you get the movement back, or you see the Physiotherapist.


Exercises

 

1. Pendulum - shown for left arm
Lean forwards. Let your arm hang freely. Start with small movements. Swing your arm: Forwards and backwards, Side to side and In circles. Repeat 5 times each movement

 

2. Lower trapezius


Sitting or standing. Keep your arms relaxed. Square your shoulder blades (pull them back and slightly down). Do not let your back arch. Do not let elbows move backwards (clasp your hands in front of you, to discourage this!). Hold for 10 seconds. Repeat 10 times, "little and often" during the day.

 

 

3. External rotation


Sitting. Keep elbow into your side throughout. Move hand outwards. Can support/add pressure with a stick held between your hands if the movement is stiff. Repeat 5-10 times.

 

 

4. Flexion in lying - left shoulder shown


Lying on your back on bed/floor. Support your operated arm and lift up overhead. Try to get arm back towards pillow/bed. Gradually remove the support. Repeat 5-10 times.

 

 

5. Flexion in standing - right shoulder shown


Standing facing a wall. With elbow bent and hand resting against wall. Slide your hand up the wall, aiming to get a full stretch. If necessary, use a paper towel between your hand and the wall to make it easier. Repeat 10 times.

 

 

6. Shoulder blade exercise


Lying face down, with head in front on a towel or turned towards shoulder. Keep arm relaxed by side. Lift shoulder straight up in air. Try and keep a gap approximately 5cms between front of shoulder and bed. Hold shoulder up 30 seconds. Repeat 4 times. Progress - by lifting the arm up and down (elbow straight) but keeping the shoulder blade up all the time. Aim to do this movement for 30 seconds. Repeat 4 times.

 

 

Who to contact if you are worried or require further information?

 

If your wound changes in appearance, weeps fluid or pus or you feel unwell with a high temperature, contact your GP.

 

If you have a query about exercises or movements, contact the Physiotherapy department where you are having treatment if you have already started.

 

We would like to thank the Nuffield Orthopaedic Centre especially Professor Andrew Carr for allowing us to reproduce this information. This has then been modified to suit local patients needs taking into account varying clinical practice. Help and feedback was given from people who have had sub-acromial decompression surgery.