What is subacromial impingement?

Shoulder impingement is a disorder of the rotator cuff; a band of muscle and tendon around the top of your arm. Spurs of bone or thickening of the ligament may develop over time and cause rubbing of the tendon, and thickening/scarring of the tendon covering (bursa). This causes a painful condition that is called impingement syndrome or subacromial impingement.

What causes the condition?

Causes of impingement include:

• Injury (e.g. falling onto your hand or elbow), repetitive use of the arms overhead, and age-related ‘wear and tear’ can all cause a swollen, thickened or torn tendon
• The fluid-filled sac (bursa) between the tendon and acromion (the bone at the end of your shoulder blade) becomes irritated and inflamed (known as bursitis) because of an injury or through overuse of your shoulder
• The acromion is misshapen/irregular, crowding into the space needed by the tendon, pinching or trapping the tendon when your arm is raised
• There are bony growths (spurs) on the acromion which can develop as you get older.
• Calcification can build up in the rotator cuff tendons

What are the typical signs?

Subacromial impingement can happen without warning or begin gradually. If you have shoulder impingement you may feel:

• Pain in the top and on the outside of your shoulder
• Sudden pain when your arm is raised, especially above your head
• Pain or aching at night
• Pain or weakness when throwing a ball or placing your arm behind your back

How is it diagnosed and treated?

Diagnosis

Your consultant will discuss your symptoms with you and perform a medical examination, which could involve asking you to carry out certain movements with your arms, hands and shoulders. This may be followed by an X-ray, MRI or ultrasound scan

Treatment

Non-surgical treatment: Home care with rest using an ice pack to help reduce the pain and any swelling. Your consultant may talk about ‘activity modification’ (avoiding the things that cause you pain). Medication, including anti-inflammatory drugs or steroid injections, as recommended by your doctor. Physiotherapy for around six weeks.

Surgery: Your consultant may recommend an operation if other treatments fail. Minimally invasive keyhole (arthroscopic) surgery is performed to remove the bone spurs and inflamed bursa and to release the ligament over the tendon that is causing painful rubbing. This is called a subacromial decompression. This is performed as a day-case operation (you come into hospital on the day of surgery and go home on the same day).

Recovery

This depends on the type of treatment you’ve had, but can take from between 4 and 8 weeks, if you’ve had surgery. Your consultant will be able to advise you on this.

When can I return to normal activities?

• Work - this depends on your individual employment and lifestyle, however if your job mainly involves sitting then an approximate guide is around three weeks post-surgery. If you have a more active role, your consultant will be able to advise you on a suitable period of time, however it could take up to four months
• Driving – on average, it is possible from two weeks onwards
• Exercise – as pain allows