What is Rotator Cuff Injury?
The shoulder joint works like a ball-and-socket connection, but it was designed to prioritize movement over stability. The part of the shoulder blade that forms the socket (glenoid) is quite shallow and has been compared to a golf ball on a tee or a basketball on a dinner plate. The rotator cuff, which is a group of four muscles attached from the shoulder blade to the top of the arm bone (humerus), plays a big role in providing stability to the shoulder. These muscles help with different types of arm motion, whether moving the arm inward (subscapularis muscle), lifting the arm for the first 30 degrees (supraspinatus muscle) or turning the arm outward (infraspinatus and teres minor muscles).
Injuries to the rotator cuff can range from minor damage to severe tears. Age is a key factor, and rotator cuff injuries are more common as people get older. In fact, around 62% of patients aged 80 or older have had some form of rotator cuff injury — even if they haven’t felt any symptoms. People with pain in one shoulder are also at risk of having a rotator cuff tear in the other shoulder. There’s a 50% chance that people over the age of 66 will have a tear in both shoulders. And while the age factor is linked with the likelihood of having a tear and the type of tear, it doesn’t necessarily determine the size of the tear.
Unfortunately, deciding on the best course of action for treating tears in people under 40 is challenging due to limited reliable evidence. The injuries in this age group often result from physical trauma and might recover better with surgery, but we need a better understanding of the effectiveness of non-surgical treatments too.
What Causes Rotator Cuff Injury?
Rotator cuff disease is most commonly seen as people get older. The condition worsens over time, and is usually a result of natural wear and tear. Another risk factor for this condition is smoking. Research suggests that smokers tend to have larger and more severe tears in the rotator cuff, which may require surgery. Family history can also play a role – studies have found that this condition can run in families up to the level of third cousins.
Interestingly, your posture could also affect your chances of developing rotator cuff disease. Patients with poor postures such as kyphotic-lordotic (hunched back), flat-back, or sway-back postures are more likely to have rotator cuff tears. Meanwhile, those with ideal posture had a substantially lower incidence of tears.
Other risk factors include traumatic injury, hypercholesterolemia (high cholesterol levels), and jobs or activities that require frequently lifting your arms overhead.
If you already have a small tear in your rotator cuff, various factors could cause it to grow larger. These include the size and location of the tear, whether you have symptoms, and your age. Bigger tears are more prone to get worse, but the exact size that increases the risk for enlargement is still unclear.
Additionally, if the tear starts to grow, you’re five times more likely to experience symptoms. Interestingly, tears towards the front are most likely to get worse. Lastly, age can significantly impact tear development; older individuals (over 60) are more likely to see their tears grow larger, whereas younger patients with complete tears are better at adapting to the stress and avoiding further tear propagation.
Risk Factors and Frequency for Rotator Cuff Injury
Rotator cuff injury is the most common type of tendon injury in adults. The likelihood of experiencing this injury increases with age. For example, about 30% of adults over 60 years old and 62% of people over 80 years old have a rotator cuff tear.
- In Germany, a study of 411 shoulders without symptoms found 23% had rotator cuff tears.
- The rate increased with age, with 31% of tears found in people aged 70, and 51% in people aged 80.
- Other studies in Europe reported slightly lower rates. An Austrian study of 212 symptom-free shoulders found only 6% had complete tears.
- A study in Norway with 420 volunteers aged between 50 to 79 found that 7.6% had full-thickness tears.
Signs and Symptoms of Rotator Cuff Injury
Rotator cuff disease often begins with pain, which can appear suddenly due to an injury, or increase slowly over time. Active individuals often seek medical attention when they can no longer participate in their activities, sports, or jobs without experiencing pain. For example, a baseball pitcher might shift their throwing technique to alleviate pain and maintain performance, but will likely seek medical help when the pain persists or their performance worsens. Depending on when the patient receives medical attention, the tendon damage could range from inflammation to a partial or complete tear.
Patients commonly report experiencing increased pain and difficulty with overhead activities and everyday tasks. Pain during heavy lifting, or discomfort radiating down to the deltoid muscle area, are also common. In younger patients, repetitive use of the shoulder often causes the condition, while older patients may also have osteoarthritis contributing to their pain.
When examining patients with symptoms of rotator cuff disease, tenderness may be noted around the area where the supraspinatus, infraspinatus, and teres minor muscles connect to the shoulder. Additionally, both muscle atrophy and disturbances in the normal movement of the scapula may be visible. The tests commonly used to diagnose rotator cuff disease, such as the Jobe or ’empty can’ test, the ‘full can’ test, resisted external rotation, and the belly press test, may cause pain or weakness if the rotator cuff is affected. While these tests can be indicative of the condition, they aren’t always specific, and diagnostic injections are sometimes used to help confirm the diagnosis.
In cases of a possible rotator cuff tear, the tests may show variations. If a patient is unable to maintain the ’empty can’ test position, it can suggest a tear. Other signs of a tear include a lag in external rotation, and an inability to keep the hand on the abdominal wall during the belly press test.
Testing for Rotator Cuff Injury
To get a clear picture of the shoulder, doctors typically use one of three imaging methods: standard X-rays, ultrasound, and a type of MRI called MRI/MR arthrography. If they suspect rotator cuff disease – a condition where the muscles and tendons in your shoulder joint are damaged – an MRI is often used. MR arthrography is similar but more expensive because it requires an injection of a medicinal dye called gadolinium, and doesn’t offer any additional benefits over an MRI.
The first imaging method used is usually X-rays, viewed from four different angles. The Grashey view captures an X-ray while your shoulder muscles are engaged, which can reveal if there’s damage to the top part of the upper arm bone or humerus. The scapular Y view helps find any bone spurs (bony projections) along the acromium, a part of the shoulder often affected by rotator cuff tears. Finally, the axillary view captures the joint space around the humerus, showing signs of narrowing or abnormal movement.
Ultrasound is another fantastic tool for checking the rotator cuff. It’s less costly than MRI and also allows doctors to assess your shoulder’s movements in real-time. A review article from 2013 compared MRI, MR arthrography, and ultrasound for diagnosing rotator cuff tears. All three methods performed well in finding both complete and partial tears, with no significant differences in their abilities to identify a tear. One limitation of ultrasound, however, is that it requires skill to capture the right images, and it might be challenging to distinguish between an old tear and chronic inflammation of the tendon, known as tendinopathy.
In the US, the MRI is considered the go-to method. The detailed images it provides are often used to plan surgical procedures since they can show the size and location of a tear, any retraction (pulling back) of the muscle or tendon, muscle wasting, long-term changes in the tendon or muscle associated with age or damage, and other related issues. All these factors help doctors to devise the best approach for potential surgery.
Treatment Options for Rotator Cuff Injury
The treatment for a torn rotator cuff can vary depending on a few factors, such as the patient’s age, their daily activities and duties, and whether the tear is a new injury or an old one that’s gotten worse.
For younger patients under 40 who have completely torn their cuff, doctors usually suggest surgery, followed by proper rehabilitation. This is because young people usually get this injury from accidents or sports, and these types of injuries tend to do well with surgery.
However, the American Academy of Orthopedic Surgeons, a leading body of experts, notes in their guidelines that while surgery can help people with fully torn rotator cuffs, the evidence supporting this is not very strong. They also mention that different treatments can be the right choice, depending on the patient’s condition. To start, non-surgical treatments, like physical therapy, can always be a good option if the patient feels better and experiences less pain with time. But even if a patient improves with non-surgical care, sometimes surgery might still be necessary. In severe cases where there’s a large, old tear, the doctor might have to clean out or repair part of the tear, or even do a complete reconstruction of the shoulder. Lastly, if the tear is past the point of repair and causing the patient great pain and loss of movement, joint replacement surgery might be the best option.
Patients who improve with non-surgical care typically start to do so within about 1.5 to 3 months. Also, those with a tear but no symptoms should start with non-surgical treatments. New tears that cause symptoms also often begin with physical therapy, which can help strengthen the muscles around the shoulder. Interestingly, in one study, patients who didn’t expect physical therapy to help were the ones most likely to end up needing surgery in the end.
Doctors may also suggest injections of a powerful anti-inflammatory drug called corticosteroids for patients with torn rotator cuffs. However, using this method alone hasn’t been proven to provide relief in the long run consistently.
What else can Rotator Cuff Injury be?
When experiencing shoulder pain, there are several conditions that could be the root cause, such as:
- SLAP or other labral tears
- Subacromial impingement, which could be due to bursitis, os acromiale or bone spurs
- Acromioclavicular osteoarthritis
- Biceps tendinitis
- Calcific tendinitis
- Cervical radiculopathy
What to expect with Rotator Cuff Injury
A recent study published in 2019 from the UK looked at the recovery rates for patients who had surgery and those who opted for non-surgical treatments. The study found that both groups showed significant improvements at 12 months, after which progress leveled off. It could not conclude that surgery was any more beneficial than non-surgical treatments.
To help doctors make the best decision for treating tendon injuries, a guidelist was created that separates patients into three different groups. Group 1 includes patients who should consider immediate surgery, such as those who’ve experienced a sudden injury, confirmed by imagery scans, especially if it involves a subscapularis tear (a tear in the muscle in the rotator cuff). This group also includes younger patients (between 62-65 years old) with small to medium-sized tears and minimal muscle damage.
Group 2 patients are recommended to consider non-surgical treatments first. These patients have partial or full-thickness tears that cause pain, but didn’t happen suddenly. Rehabilitation has shown to be beneficial for these patients in improving their function and health outcomes.
The third group includes patients who aren’t likely to benefit from surgery because their tendons are unlikely to heal. This includes patients over 70 years old, those with chronic full-thickness tears with significant tendon retraction, advanced muscle degeneration, and any signs of proximal humeral migration, which means the top part of their arm bone is moving out of place.
Possible Complications When Diagnosed with Rotator Cuff Injury
The main possible issue following the repair of a torn cuff would be additional damage to the repaired area. This risk can typically be minimized by carefully deciding which patients are suitable for the procedure. In addition to general postoperative complications, patients may experience adhesive capsulitis, a condition causing stiffness and pain in the shoulder joint. Other potential problems could include a failure to recover normal movement or strength in the cuff.
Potentially Likely Complications:
- Additional damage to the repaired cuff
- Adhesive capsulitis (stiffness and pain in the shoulder joint)
- Inability to regain normal movement
- Lack of recovery of cuff strength
- Other general postoperative complications
Preventing Rotator Cuff Injury
Currently, there aren’t any studies that have explored strategies to prevent rotator cuff tears. However, the theory exists that maintaining a properly functioning rotator cuff may help reduce the risk of them deteriorating over time. In one study, it was observed that rotator cuff tears seemed to occur more often in people who maintain certain postures.
Furthermore, another study was conducted examining the distance between the acromion (part of your shoulder blade) and the humerus (upper arm bone), known as the acromiohumeral space. It found that a smaller than normal space correlated with a posture where the upper back is excessively curved forward, also known as a hyperkyphotic posture.
