Rotator cuff pain

What is rotator cuff pain?

Rotator cuff pain is one of the most common causes of shoulder pain in our practice. It is a spectrum of conditions that includes tendon inflammation (tendinosis), partial thickness and full-thickness tears to the rotator cuff tendons. Rotator cuff pain can be sequelae of shoulder impingement and is often associated with subacromial bursa inflammation (sub-acromial bursitis). Another cause of rotator cuff pain is calcific tendonitis. This happens due to calcium deposition within the rotator cuff tendons and can be very painful. It is discussed in a separate article.

Relevant anatomy

The shoulder is a ball and socket type of joint. The ball is formed by the humeral head (the upper end of the arm bone), and the socket is formed by the glenoid, part of the shoulder blade that articulates with the humerus. The rotator cuff muscles are located at the front, back and on top of the shoulder blade and consist of 4 muscles (the supraspinatus, infraspinatus, subscapularis and teres minor tendons). Their tendons form a complete tissue cuff that attaches to the humerus (the ball component of the shoulder joint). The rotator cuff muscles and tendons are vital in shoulder movement and stability. They are essential for shoulder rotation and lifting the arm and ensure the ball remains well-centred within the socket throughout the range of movement. The supraspinatus tendon is the one most commonly affected by the disease. Dr Al-Ani has published an article about the various conditions that can affect the rotator cuff tendons.

The rotator cuff tendons run immediately underneath the subacromial bursa, an important anatomical structure. A bursa is a thin fluid-containing sac usually seen adjacent to a bone to provide cushioning effect and protection. We have a few of these within our body (like in the shoulder and hip). Unfortunately, these can get injured or irritated, resulting in bursal inflammation (bursitis). The sub-acromial bursa is the largest in the body, located within the shoulder and runs on top of the rotator cuff tendons. It ensures smooth gliding of the rotator cuff tendons during shoulder movements. Sub-acromial bursitis refers to inflammation of this bursa and is very commonly seen in rotator cuff disease/pain.

What are the clinical features of rotator cuff pain?

The usual symptoms of rotator cuff disease/pain are:

Shoulder pain can be felt at the front or back of the shoulder. The pain can also go down and be felt in the upper arm.
The pain worsens when lifting your arm, especially above head level.
Weakness in the shoulder, especially when you are lowering your arm.
In severe cases, you may have pain at night, especially when sleeping on the affected side.

What are the causes of rotator cuff pain?

The spectrum of rotator cuff disease includes:

1: Rotator cuff tendinosis/tendinopathy. This refers to inflammation and thickening of the rotator cuff tendons without a tendon tear. The thickening and swelling of the rotator cuff tendons are often associated with inflammation within the subacromial bursa (sub-acromial bursitis), and both could be the sequelae of shoulder impingement.

2: Rotator cuff tear. This refers to a tear in the tendon, which is more significant. A rotator cuff tear can happen gradually due to repetitive overload or be secondary to a certain and specific injury (like a fall over the shoulder). Rotator cuff tears are divided into partial thickness (which involves only part of the tendon's thickness) and full thickness (which involves the full thickness of the tendon). The latter is more significant and can result in more weakness.

3: Calcific tendonitis (shoulder calcification). This refers to calcium deposition within the rotator cuff tendons, which can be very painful. It is discussed in a separate article.

What other conditions can mimic rotator cuff problems in the shoulder?

Other shoulder problems that can present similarly are:

Rotator cuff pain vs frozen shoulder

Both of these conditions can cause significant shoulder pain. Frozen shoulder is a progressive disease that can worsen over time and has 3 stages. It is also associated with shoulder stiffness and significant limitation of shoulder movements, particularly trying to move your arm to the outside (external rotation). Rotator cuff pain typically happens when raising the arm above the head level. There might be weakness in the movement if there is a rotator cuff tear.

How to diagnose the cause of rotator cuff pain?

The diagnosis of rotator cuff pain and shoulder impingement is clinical. Your doctor will establish it during the examination. A shoulder ultrasound scan will be extremely useful in confirming the diagnosis and assessing for any tear within the rotator cuff tendons (the ultrasound images below show a normal supraspinatus tendon on the left vs a torn tendon on the right). In addition, ultrasound is used to guide injection treatment in the shoulder when indicated. Evidence has shown that performing these injections under ultrasound guidance results in better outcomes in shoulder pain when compared to non-guided injections. The shoulder bursa is very thin (2-4 mm in thickness); therefore, ultrasound guidance is necessary to ensure injecting the medicine accurately.

What is the treatment for rotator cuff pain?

Management of rotator cuff pain depends on the condition. Tendinosis is usually treated with a physiotherapy program to strengthen and rehabilitate the rotator cuff muscles, along with anti-inflammatory tablets, icing and activity modification to avoid movements that can worsen the condition. If the results from conservative treatment are inadequate, then a subacromial bursa steroid injection might be indicated.

If there is a tear to the rotator cuff tendon, then the management would depend on the size and location of the tear, your age, and the expected degree of shoulder activity. Shoulder ultrasound will provide valuable information about the rotator cuff. Small tears might be managed conservatively +/- with ultrasound-guided sub-acromial steroid injections. A large (full-thickness) tear in an active individual may require surgery. You should speak to a shoulder specialist doctor to discuss the best treatment options.

What type of injection is useful for rotator cuff pain?

1: Ultrasound-guided steroid injection

This is one of the most common injections we perform for patients with rotator cuff pain. Usually, a long-acting corticosteroid (Depomedrone) is injected accurately under ultrasound guidance into the sub-acromial bursa. Steroids are strong anti-inflammatory medicines that help reduce the pain and inflammation in the area. They will provide a good window for you to achieve better results with physiotherapy and rehabilitation. Please read our article about ultrasound-guided sub-acromial bursa steroid injections to learn more,

2: Platelets-rich plasma (PRP) injections

These can be considered in certain cases of partial thickness rotator cuff disease.

3: Barbotage/lavage. This is a special procedure aimed at extracting the calcium deposit in cases of calcific tendonitis. To learn more, read our article about Barbotage/lavage for calcific tendonitis.

How many shoulder steroid injections can I have for rotator cuff problems?

We try to limit the number of injections patients have. Following the injection with an effective physiotherapy program will help reduce the need for a second injection. If a repeat sub-acromial bursa steroid injection is being considered, it should be at least 3-4 months from the last injection.

Will a cortisone injection heal a rotator cuff tear?

The answer is no. Cortisone reduces the inflammation around the tear and in the bursa but it will not lead to tear healing.

Can PRP injections heal a rotator cuff tear?

We are uncertain yet. We do not think that PRP injections would help heal complete (full-thickness) tears. PRP injections can be used to treat partial tears with some studies showing good results in terms of improvement in pain and function but we are unsure yet if they actually cause any healing to the tear.

Rotator cuff tendinosis vs. sub-acromial bursitis

The two conditions result in very similar symptoms and often are seen in association. When there is extra stress upon the rotator cuff tendons, the bursa often gets inflamed (bursitis) and the tendons also show inflammation because of increased stress (tendinosis). The management of the two conditions is also very similar.