Rotator cuff injury

It's a type of shoulder injury to the rotator cuff. The rotator cuff is a group of four muscles and tendons around the shoulder joint. These muscles keep the head of your upper arm bone firmly in the shallow socket of your shoulder. They support your shoulder and help it move. 

Problems with the rotator cuff are a common cause of shoulder pain. It can cause a dull ache that's often worse when you try to sleep on the affected side or use your arm away from your body.

Rotator cuff injury is common. Your risk is higher as you get older and if your work involves repeated overhead movements eg painting. Usually symptoms can be managed at home. You may need to perform different exercises (excluding overhead movements) and have physiotherapy to regain your full range of movement. Painkillers and steroid injections may also be needed. 

Surgery may be an option. Some rotator cuff tears are caused by a single injury, which can be repaired with surgery. Other rotator cuff tears can't be repaired and may need alternative surgery to attach other tendons to the joint bones or to replace the joint. 

Your shoulder comprises three bones: 

• The collarbone (clavicle) 
• The shoulder blade (scapula) — a triangle-shaped bone with two important parts, the acromion and the glenoid
• The upper arm bone (humerus)

These three bones are part of two main joints:

• The acromioclavicular joint — this forms between the acromion part of the scapula and the clavicle
• The glenohumeral joint — this forms between the glenoid part of the scapula and the humerus

The shoulder also contains muscles, ligaments and tendons. Ligaments connect bones together at a joint, while tendons attach muscles to bones.

The rotator cuff stabilises your shoulder joint and helps your shoulder move. Each of its four muscles is attached to a tendon; these four tendons join together to form one large tendon called the rotator cuff tendon. This tendon attaches to the head of the humerus.

The rotator cuff tendon passes through a space under the acromion part of the scapula called the subacromial space. This space contains fluid-filled sacs (bursae), which have many pain sensors.

Symptoms of a rotator cuff injury include:

• Frozen shoulder
• Intense pain when you raise your arm above your shoulder eg when combing your hair, dressing or performing activities such as basketball, painting and swimming — you may feel a catching or clicking when you move your shoulder, but writing and typing may not cause much or any pain
• Pain in and around your shoulder joint
• Pain may be long-term (chronic), which sometimes gets worse at night, or acute eg a sudden tearing sensation
• Reduced movement in your shoulder
• Weakness in your shoulder and arm

If you experience shoulder pain along with other symptoms, such as chest pain or tightness or shortness of breath, then seek immediate medical help.

Your GP will ask you some questions about your shoulder, such as: 

• Have you had any specific injury?
• What makes your shoulder problem worse?
• When did your shoulder problem start?

They will also examine your shoulders for pain and movement. This involves gently moving your shoulder into different positions and comparing it with your unaffected shoulder.

Your neck will also be checked to make sure your shoulder pain isn't referred pain (pain that's felt in another part of the body than its actual source) from conditions affecting your spine.

Your doctor may also ask you about any recent chest pains to rule out a possible heart condition.

Your doctor may recommend some other tests to rule out a broken bone or another condition. Tests include:

• MRI scan
• Ultrasound scan
• X-ray

The causes of a rotator cuff injury can include:

A rotator cuff tear after an injury

Tears caused by an injury, such as a fall or a dislocated shoulder. 

Your rotator cuff is most vulnerable to damage in the subacromial space. Tears can be painful but also make your shoulder weak. They can be detected with an MRI scan or an ultrasound scan but not an X-ray. 

They can be minor (partial tears) or full (complete tears) depending on the extent of damage to your rotator cuff tendon. Minor tears are very common and may not cause any symptoms. Small tears can be very painful while larger ones are usually less painful.

A rotator cuff tear caused by chronic overuse

Repetitive overhead use of your arm at work or sport increases the risk of a rotator cuff injury. For this reason, it often affects painters, carpenters, cricketers and racket players.

Subacromial impingement

Also known as bursitis, shoulder impingement, tendonitis and trapped tendon. Normally, when you lift your arm up, the rotator cuff tendon pushes the top of your humerus under the acromion. Damage to your rotator cuff eg tears or overuse after a period of inactivity can prevent the head of your humerus being pushed down properly. This causes your rotator cuff tendon to press against the acromion, which is painful. This can be caused by arthritis or bone spurs on your acromion. 

Calcific tendonitis

This is when calcium builds up in your rotator cuff tendon, increasing pressure in the tendon and causing irritation — it can be extremely painful. It isn’t known exactly what causes it but it is more common in those aged 30-60. The calcium can affect how your rotator cuff functions and cause subacromial impingement. However, a build-up of calcium is also seen in people with no symptoms. 

Degenerative wear and tear

Degeneration of the muscles and tendons is known as tendonitis and is more common in women aged 35-50. Bony overgrowths, also associated with ageing, can weaken the tendon and cause tears.

• Age — risk increases as you get older, with rotator cuff injuries most common in those aged over 60 
• Family history — rotator cuff injuries can run in families, suggesting a genetic risk factor
• Working in construction — manual jobs, such as carpentry and house painting, involve repetitive arm movements, which are often overhead, causing damage to the rotator cuff with time

Do not work or play through your pain. Instead, avoid activities that worsen your pain eg those involving overhead movements — you may need to change your work activities to accommodate this. However, you should not completely rest your shoulder as inactivity can weaken your muscles. 

Treatments for rotator cuff injury include:

• A sling to help rest your shoulder
• Anti-inflammatories eg ibuprofen — ask your doctor about using them first
• Applying an ice pack
• Resting your shoulder
• Rotator cuff exercises

To keep your shoulder mobile and strong, it may help to see a physiotherapist. They can prescribe an exercise programme for you to do at home if your symptoms are taking a while to resolve.

Steroid injections can help reduce your pain in the case of a chronic injury. This will allow you to complete an exercise programme recommended by your physiotherapist. Steroid injections may also reduce inflammation in the subacromial space. If you respond well to your first steroid injection, your doctor may recommend a second injection after six weeks. However, it is not recommended to have more than two injections. 

In more serious cases or cases where a tear caused by a sudden injury has not improved with physiotherapy and steroid injections, you may need rotator cuff surgery. This could involve:

• Full shoulder joint replacement in extreme cases
• Open tendon repair
• Rotator cuff repair using arthroscopy — this is a type of keyhole surgery
• The transfer and use of tendons from another part of your body

If you have calcific tendonitis, your doctor may recommend ultrasound-guided barbotage. This procedure uses a needle to inject the calcium deposits in your rotator cuff with saltwater and then suck them out via a syringe.

With proper treatment, including daily exercises to keep your shoulder muscles strong, you can fully recover from a rotator cuff injury. It usually takes at least six months.  

Without proper treatment, a rotator cuff injury can cause permanent loss of motion or weakness and/or degeneration of your shoulder joint. 

If you completely rest your shoulder and do not carry out exercises to strengthen it, you can get a frozen shoulder.

To prevent future injury to your rotator cuff, perform daily exercises to strengthen your shoulder. Make sure you strengthen: 

• The muscles at the back of your shoulders and around your shoulder blade 
• The muscles at the front of your chest, shoulders and upper arm

A doctor or physiotherapist can prescribe an exercise programme for you to do at home.