What is the rotator cuff in the shoulder and what is a rotator cuff injury?
On this video, you’ll learn about rotator cuff injuries causing shoulder pain. If you’ve ever had pain in the shoulder, you can understand how limiting this sort of injury and pain can be. There are a number of different things that can cause shoulder pain. They can include an injury to the rotator cuff tendons, it can also include a strain to the ligaments around the shoulder, and arthritic component to the shoulder joints. In addition, you can also have pain in the shoulder that comes from the neck whether that’s a pinched nerve coming from the neck or actual arthritis in the neck. In this video however, I’ll be talking and focusing on rotator cuff injuries coming from the shoulder itself.
So what is the rotator cuff. The rotator cuff are four muscles and by extension their tendons that help to stabilize the shoulder joint. These muscles include the supraspinatus, infraspinatus, subscapularis, and teres minor tendons. The biceps tendon is a tendon within the shoulder itself and offers stability. However, it’s not actually part of the rotator cuff. The rotator cuff muscles start at the shoulder blade or the scapula, and then extend to the humeral bone where the tendons then insert. The purpose of the rotator cuff is to stabilize the humeral head and thus the shoulder joint when moving through a range of motion. They do this by the muscles contracting individually, but in a coordinated fashion. The supraspinatus helps the shoulder to abduct or lift the arm above the head. The infraspinatus and teres minor tendons help with external rotation of the shoulder. And the subscapularis tendon helps with internal rotation.
Rotator cuff injuries come in different types. At the most mild there’s tendonitis or tendinopathy which really means irritation to the tendon. There’s any progression where you can then develop rotator cuff tears, which means disruption of the fibers. This is a range in spectrum of injury. Meaning you may start with a rotator cuff tendinopathy and with time and due to instability you can then develop progressive tearing of the tendon. Thinking of rotator cuff tears as a spectrum of injury. There’s a grade one tear where you’ll have fraying or a mild injury to the tendon. A grade two tear where you now have more of a significant partial thickness or a portion of the tendon where the fibers are disrupted. And then finally you’ll have a grade 3 tear where there’s an entire disruption of the fibers of the tendon. In that full thickness tear category, you can have a tendon tear where the edges of the tendon are still closely approximated, and you can then have tendon tears where they are fully pulled apart and retracted.
The usual cause for a rotator cuff tear includes repetitive overhead activity whether that’s at work or with sports or other types of activities anything that stresses the actual shoulder joint and soft tissue around it. In general people have likely had an acute or chronic injury and usually there’s really multiple successive injuries. It can start off relatively mild where there’s a ligamentous injury to one of the ligaments that helps support the bones. That sort of mild injury can then lead to progressive instability which in turn then leads to progressively putting more stress on the rotator cuff tendons, and then eventually leading to enough accumulated damage that leads to a partial and then sometimes even a full thickness tear of the tendon.
What’s interesting is that the degree of tendon tear does not always correlate with the degree of pain it can correlate with a degree of weakness in the shoulder but not necessarily pain. You can have significant pain if you’re still at a relatively early stage of that sort of process. And you may actually have less pain when you have a full thickness tear but it’s important to understand that the degree of damage that you see on imaging does not always correlate with pain and thus even if you have a mild injury, you should consider some sort of treatment at an earlier stage. And even if you have a significant injury that can sometimes still be treated with conservative measures as well.
Symptoms from a rotator cuff injury typically involve pain in the front, the side, or the back of the shoulder. This can go further down the arm as well and even into up into the neck. If there’s a significant tear you can have weakness in the shoulder. Significant instability in the shoulder will lead to impingement or reduce range of motion in the shoulder, and significant pain with range of motion as well.
Diagnosis of a rotator cuff injury and tear involves a good dedicated evaluation by a musculoskeletal expert. First and foremost do you have a pretty good history of a injury pattern or recurrent stress actually on the shoulder. It’s important to be able to differentiate between what is a injury and pain derived from the shoulder versus pain that may be coming from the neck. A good physical exam is very key in that regard. Do you have findings on examination that indicate stress or an injury to the rotator cuff or do you have findings that are more indicative of pain that may be coming from the neck.
Next Imaging can be very helpful. What I recommend first line is generally a basic x-ray of the shoulder to look to see if there’s any bone pathology and then a diagnostic musculoskeletal ultrasound. With ultrasound you can get a really great look at the rotator cuff tendons. You can see the tendons as they move in a dynamic motion. And while you’re moving the arm as well to get a better look at tendons and to see what’s happening when you’re moving through a range of motion to see if there’s any impingement or subtle little tears. MRI does have utility as well. There’s certain things that ultrasound is not as good at looking at. That includes a labral tear which is the ring of tissue around the shoulder joint. As well as if you have any sort of swelling or bone marrow edema within the subchondral space of the bone of the humerus and shoulder bones as well. But when you’re looking at rotator cuff injuries and tears, I personally find that an ultrasound gives you a better and more nuanced look at the actual injuries to the tendon itself.
So now that you understand more about the rotator, cuff rotator cuff injuries, and tears that can cause shoulder pain, tell me if you’ve had shoulder pain, did you have a rotator cuff injury and how was it treated? If you found this content interesting or useful, and you would like to learn more about your musculoskeletal health and wellness consider subscribing to this channel or to my email newsletter.
Thank you for your time. Have a good day and live well.