What is Supraspinatus Tendonitis?
Doctors in general practice, sports medicine, and orthopedics often deal with shoulder injuries and shoulder pain. In fact, up to half of all shoulder-related issues are usually addressed in a single visit to a family doctor. One common cause of shoulder problems comes from issues with the rotator cuff, a group of four muscles and their connecting tendons in the shoulder: the supraspinatus, infraspinatus, teres minor, and subscapularis.
Rotator cuff problems can lead to a lot of pain and disability for many different patients. If someone injures their rotator cuff, they might experience a range of issues, from slight damages to a complete tear in the tendons. Older beliefs about rotator cuff injuries suggest that these problems can lead to the eventual failure of the rotator cuff.
For a long time, people believed that rotator cuff issues were caused by the rotator cuff rubbing against a rough area on the shoulder blade acromion (undersurface) during certain movements. This was known as the impingement phenomenon and this idea was widely accepted and used to understand shoulder issues.
The next sequence of events, according to this belief, would involve the supraspinatus tendon (one of the four rotator cuff tendons) going through three identifiable stages: swelling and bleeding, scar tissue forming and inflammation, and finally tearing.
However, recent research and understanding have added more nuance to this theory, questioning its accuracy. Nowadays, doctors have a more comprehensive view of rotator cuff problems, including identifying different types of ‘impingement’ or rubbing problems.
What Causes Supraspinatus Tendonitis?
The supraspinatus tendon in the shoulder experiences the most stress when you lift your arm out to the side, a motion known as abduction. It helps keep the top part of your upper arm bone, the humeral head, centered in the shoulder socket, and assists the deltoid muscle in keeping strength and control. The tendon connects to the uppermost and forward parts of the bony bump at the top of your upper arm. It’s shaped like a triangle and measures about 6.9mm side-to-side and 12.6mm front-to-back. The spot that’s most susceptible to damage is where it connects to the bony bump under a part of the shoulder blade called the acromion.
Rotator cuff problems, including issues with the supraspinatus tendon, can happen because of injuries or because of wear and tear over time. Some people are more prone to these issues, including heavy laborers, overhead workers, or those with certain physical traits. Some data suggest that about half of all rotator cuff repairs are needed because of injuries, and the other half due to gradual wear and tear. These issues can come up after certain kinds of injuries, like lifting something heavy, shoulder dislocations, falls, or other unexpected arm movements.
While some rotator cuff tears can happen because of one specific event, it’s thought that around 95% of tears actually start with supraspinatus tendonitis. This happens when the tendon gradually wears down with repeated arm lifting movements, in a situation often referred to as “external impingement” of the shoulder.
However, some studies have challenged this 95% figure, and there’s also evidence that some people might have a genetic predisposition to rotator cuff issues. This could make someone more likely to have rotator cuff tendonitis or tears. Given these factors, it’s hard to pin down exact chances among diverse groups of people, but both injury and wear and tear could contribute to issues with the supraspinatus tendon.
Risk Factors and Frequency for Supraspinatus Tendonitis
Rotator cuff problems are quite common, especially among people in their 80s, with around 50% being affected. Various studies show the frequency of rotator cuff issues to be different among different age groups. A study using MRI scanning reported that 20% of people had partial rotator cuff tears, while 15% had tears that went all the way through. These issues were found more often in people over 60 years old.
- A study highlighted that military personnel experience something called subacromial impingement at a rate of roughly 7.77 per 1000 people each year.
- Being over 40 years old increases the risk of getting subacromial impingement and consequently supraspinatus tendonitis, another rotator cuff issue.
- While it’s hard to determine the exact frequency of supraspinatus tendonitis, these findings can give us an idea about its frequency.
- It’s interesting to note a condition called internal impingement, mainly affecting those who do activities like throwing or overhead sports. It involves the inner side of the posterior rotator cuff.
Signs and Symptoms of Supraspinatus Tendonitis
Rotator cuff issues don’t just affect the top portion of the shoulder. The most common symptom of a rotator cuff injury is pain. This pain could either be on the side or at the front of the shoulder. Different types of pain can indicate various shoulder problems. For example, front shoulder pain might be caused by issues with the upper part of the bicep tendon. On the other hand, pain on the side or front-side of the shoulder could be due to problems like subacromial impingement or rotator cuff dysfunction. If someone is experiencing pain at the back of their shoulder, it might be because of degenerative conditions in the shoulder or pain referred from the neck.
Pain becomes more noticeable with overhead movements among patients suffering from subacromial impingement. These patients might also report a feeling of weakness. Approximately 98% of cases report pain as their main concern. These symptoms may include a deep shoulder ache, sleep disturbances or weakness.
The shoulder should be inspected for any noticeable differences in appearance. Look for any abnormalities such as scapular winging or dyskinesia. When performing a focused examination of the supraspinatus, a muscle at the back of the shoulder, the patient is asked to lift their arm forward. Pain while lifting or pain at certain angles may point towards rotator cuff problems. One should be careful to exclude adhesive capsulitis, a condition that restricts shoulder movement, as the cause. In cases of isolated supraspinatus tendinitis, the patient should have a full range of motion when their arm is moved passively.
Patients with only rotator cuff issues or tendonitis should have normal neurovascular examination results. However, if the patient shows decreased pulses with the arm positioned overhead, abnormal sensations, or weakness outside the shoulder area, other diagnoses, such as cervical radiculopathy, thoracic outlet syndrome, brachial plexopathy, or peripheral nerve compression should be considered.
Two specific tests may be used to check for issues. The Hawkins test involves the patient forward flexing their arm to 90 degrees, and then passively rotating their arm inward. Pain experienced during this test could be a sign of inflamed bursa or tendon. The Jobe test involves the patient resisting a downward force while their arm is in a certain position. Any pain or weakness during the test may indicate damage to the supraspinatus muscle.
A combination of these findings can suggest various possible diagnoses such as subacromial bursitis, external shoulder impingement, or supraspinatus tendonitis. Severe or painless weakness may suggest a complete tear of the supraspinatus, but the absence doesn’t rule out diagnosis.
Testing for Supraspinatus Tendonitis
If you’re dealing with shoulder pain, the first steps in figuring out what’s wrong can vary. Many times, a physical examination is enough to provide a diagnosis and you won’t need further testing. However, if you’re experiencing severe weakness, swelling, redness, or an abnormal shape in your shoulder, you might need more thorough tests.
These tests often include different types of x-ray views in order to get a full picture of what could be causing your shoulder pain. For example, a test called a supraspinatus outlet view can provide a better look at a part of your shoulder called the acromion.
The Dutch Orthopedic Association has guidelines for dealing with something called subacromial pain syndrome – a type of shoulder pain. Their advice includes starting off with anti-inflammatory medicines, and getting a special type of scan called an MRI if the pain continues for more than six weeks. An MRI scan can show in more detail if there are any tears in your shoulder and how inflamed it is. This approach might be helpful in planning and managing your care.
In cases where your doctor might not be entirely sure what’s causing your pain, an MRI – without the use of a contrast dye – is the best way to get a detailed view of the soft tissues in your shoulder. This is generally the course of action for patients whose treatment isn’t improving after more than six weeks, for those who have severe symptoms, or when the diagnosis isn’t clear.
Athletes and those who swim or do activities that involve a lot of shoulder movements might experience “secondary impingement.” This is a group of symptoms that includes overuse and instability. Reports show that athletes who have lax shoulders, abnormal movement of the shoulder blade (scapular dyskinesia), and train frequently might experience this issue. The best ways to manage this condition include resting, physical therapy, and gradually returning to activities. It’s a different type of issue from age-related shoulder conditions and should be considered as a possible cause of shoulder pain in younger and more active people.
Treatment Options for Supraspinatus Tendonitis
Less than one in four patients will need surgery even if their condition worsens to a full-thickness tear, a type of severe tear affecting the entire thickness of a tendon or muscle. Most patients will get better with standard non-surgical treatments, such as anti-inflammatory medication and physical therapy. A study in 2017 showed that physical therapy and NSAIDs (drugs used for reducing pain, inflammation, and fever) were effective in treating subacromial impingement, a common cause of shoulder pain. However, the evidence from the study was not very strong.
Injections of corticosteroids and a local anesthetic in the space above the shoulder joint, known as a subacromial injection, may also help with diagnosis and treatment.
However, there is ongoing debate about the long-term use of corticosteroids (powerful anti-inflammatory medicines) beyond eight weeks. If a patient needs to undergo surgery for rotator cuff repair, it’s also unclear how corticosteroids used before surgery might affect the healing afterwards. Some evidence suggests that injections with corticosteroids may only increase the risk of re-tearing if they are injected after the surgery. So, a single subacromial injection might be beneficial for patients who do not get better with initial anti-inflammatory medications and exercises. Multiple injections may not be a good idea, particularly without further imaging tests and a discussion of the risks.
There are also differences of opinion regarding the surgical treatment of supraspinatus tendinitis, a condition causing pain and weakness in the shoulder. Some studies suggest that surgery to relieve pressure in the subacromial space, with or without reshaping the shoulder blade (acromioplasty), can lead to significant improvement. But other studies argue against surgical intervention unless there’s a symptomatic rotator cuff tear, a tear in the group of muscles and their tendons that stabilize the shoulder. Based on current understanding, routine surgery for supraspinatus tendinitis is generally discouraged unless there’s MRI evidence of a tear. However, once a patient has tried all non-surgical treatments without success and where certain risk factors are present, surgical intervention is considered a viable alternative.
About prognosis, a significant number of untreated supraspinatus tendinitis cases may progress into a rotator cuff tear. In some patients, early changes may not show symptoms and may go unnoticed until the tear has been present for some time. Research has shown that a significant number of patients had a rotator cuff defect that worsened and caused symptoms over time. So, patients with rotator cuff tendinitis may benefit from early non-surgical interventions to improve their outlook.
What else can Supraspinatus Tendonitis be?
When a doctor is trying to identify the cause of shoulder pain, they might consider several possibilities, including:
- Subacromial impingement (pressure on the muscles in the shoulder)
- Partial or complete tear of the rotator cuff (muscles and tendons in the shoulder)
- Tendonitis in the bicep (inflammation in the tendon)
- Arthritis in the shoulder joint or the joint where the collarbone meets the shoulder blade
- Adhesive capsulitis (also known as frozen shoulder)
- Calcific tendonitis (calcium deposits in the tendon)
It’s important to note that these conditions often occur along with inflammation in the supraspinatus tendon, a tendon located on the top of the shoulder, and can exist at the same time.
Possible Complications When Diagnosed with Supraspinatus Tendonitis
Supraspinatus tendonitis can lead to various complications, which can include developing into a rotator cuff tear. This happens when tendon inflammation and blood clots are left untreated. Numerous studies have indicated that repeated incidents of tendonitis might eventually necessitate surgical intervention. At the time of surgery, it’s common to observe some wear and tear in the rotator cuff.
This has been explored extensively using ultrasound observations of shoulders with no symptoms. In such cases, when the rotator cuff shows subtle signs of damage (subclinical rotator cuff tendinopathy), it’s seen that there’s more than a 50% likelihood it will progress to a stage with noticeable symptoms.
Common Complications:
- Progression to a rotator cuff tear
- Need for surgery due to recurring tendonitis
- Attrition of the rotator cuff
- Subclinical tendinopathy becoming symptomatic
Preventing Supraspinatus Tendonitis
It could be helpful for patients to learn about the correct techniques for performing work that involves raising their arms over their heads. However, since the disease is so common, it’s unlikely that we are able to completely prevent it. It’s important to understand that part of managing these health conditions requires the patient to take an active role.
Therefore, teaching patients about the importance of non-surgical treatment methods, the potential progression of the disease, and the different options available for taking care of their shoulders can empower them to be more involved in their own healthcare. This education allows patients to better understand their situation and participate in decisions about their treatment.
