This blog is designed to give you the baseline information that will be helpful if you go to the doctor with a suspected rotator cuff problem.
Anatomy and Function of the Rotator Cuff
The rotator cuff is made up of four muscles and tendons: the supraspinatus, above the spine of the scapula (shoulder blade); infraspinatus, below the spine of the scapula; the teres minor, in the back of the shoulder; and the subscapularis, below the scapula. The supraspinatus is on top, the infraspinatus and the teres minor are in the back, and the subscapularis is in the front. The supraspinatus is the most commonly injured rotator cuff muscle.
One of the main functions is to keep the humeral head, or the ball at the top of your upper arm, centered in the glenoid, which is the socket on your shoulder. The shoulder socket is very shallow, so the ball moves around very easily. If you think of a golf ball on a tee turned sideways, that gives you an idea of how the ball and socket interact. Without the rotator cuff muscles stabilizing the ball in the socket and keeping it centered the powerful muscles around the shoulder would move the ball out of position.
The rotator cuff muscles also help your arm move, specifically in abduction or moving your arm away from the side of your body and in internal and external rotation.
Rotator Cuff Conditions and Causes
Conditions of the rotator cuff are a continuum, going from the least disease to the most disease.
- Rotator cuff tendonitis, also called impingement or bursitis.
- Partial thickness rotator cuff tear, where one or two tendons have a partial tear but the muscle is still attached to the bone.
- Full thickness rotator cuff tear, where the entire tendon is torn off the bone.
- Rotator cuff arthropathy, where the shoulder develops arthritis due to a torn rotator cuff.
Rotator cuff tears can occur due to trauma or injury. For example, you fall, or you’re trying to get something heavy down from a shelf and it lands heavily in your arms. You feel a sudden tear or pop and have a traumatic tear.
Rotator cuff tears can also happen without injury. Called degenerative tears, these usually happen as people get older and have more wear and tear on their joints. Commonly these are diagnosed not from a specific event but from a group of symptoms when a patient is in the office. There is usually pain on the side of their shoulder and pain that’s worse with reaching overhead or away from their body. They may have trouble moving their arm, from pain or from weakness due to torn muscles. Additionally, pain at night that makes it hard to sleep is a sign of rotator cuff tears. As people develop rotator cuff arthropathy and arthritis in the shoulder, they also often have crepitus or a grinding sensation in their shoulder.
Some people may have acute on chronic rotator cuff tears, where the traumatic and degenerative causes both occur. They can have a degenerative tear that has developed over time and then have an injury such as a fall that causes the tear to worsen.
Risk Factors for Rotator Cuff Tears
Age is one of the largest risk factors for rotator cuff tears. For people who are at least 66 years old with a rotator cuff tear on one side, there is a 50% chance of having a tear on the opposite shoulder even without any pain or other symptoms.
Twenty-five percent of people who are over age 60 have a rotator cuff tear without pain. By age 70, some studies suggest over 70% of people have a rotator cuff tear, although it does not bother many of them so they are unaware.
Trauma is a risk factor in rotator cuff tears, and dislocation is a common cause. Younger people who have shoulder dislocation from sports injuries usually do not have a rotator cuff tear. Starting at age 40, however, people who have a shoulder dislocation have a 50% chance of getting a rotator cuff tear from the dislocation. At age 70 and above, everyone who has a shoulder dislocation has a rotator cuff tear.
Genetics is another risk factor for rotator cuff tears. In a study that looked at siblings and spouses of people with a rotator cuff tear, the siblings were twice as likely to have a full thickness rotator cuff tear and five times more likely to develop symptoms from it compared to the spouses.
Having some health conditions also increases your risk of rotator cuff tears: high cholesterol, diabetes, obesity and smoking. These factors can also have effect in recovering from surgery.
Studies are inconclusive if your job or your hand dominance have any effect on rotator cuff tears, but some studies suggest that your dominant side is more likely to suffer a rotator cuff tear and people who have more labor-intensive jobs and are lifting heavier weights are also more likely to sustain a tear.
Of course, all of the risk factors can overlap and any combination of these or other issues may play a role in a tear.
Examining the Rotator Cuff
The surgeon will talk with you to find out the history of your shoulder pain and then will examine you. Every surgeon’s exam is slightly different, but they follow the same basic outline. There are 17 muscles that attach to your scapula (shoulder blade) so the surgeon is trying to see if the cause of the issues is one of the four rotator cuff muscles or a different muscle.
The surgeon will look at you to see if there’s muscle atrophy or how you’re carrying your shoulder. The surgeon will touch your shoulder to see where you hurt. The surgeon will see how far you can move your shoulder and will also move it for you. They will test your muscle strength and try to pinpoint the pain.
Depending on your symptoms and personal history, the surgeon will also do a neck exam, because neck pain may feel like shoulder pain.
Additionally, the surgeon will order x-rays. While x-rays only show the bony architecture and not the muscles and tendons that might be involved, it’s important to get a sense for what the structure of your shoulder is and can help identify any degenerative or arthritic changes that might be contributing to your pain.
Your surgeon will order an MRI for acute tears because they typically need to be fixed more quickly. On the other hand, if your surgeon suspects you have a tendonitis or a partial tear, an MRI may not be necessary because they can often be successfully treated with rest, modifying your activities and avoiding the activities that are making your pain worse. Physical therapy can be extremely helpful with treating rotator cuff pain, as can a steroid injection, a powerful local anti-inflammatory delivered right to the source of the pain.
Rotator Cuff Repair Surgery and Recovery
In a rotator cuff repair surgery, anchors are placed into your bones. The anchors are like a fancy screw and will eventually dissolve and turn to bone. They have very high strength sutures, or strings, come out of them. The surgeon passes the sutures through the rotator cuff tendon and ties knots to connect the torn tendon onto the bone to help it heal.
After surgery, you’ll be in a sling for two weeks before you start physical therapy. After two weeks, you’ll start physical therapy with the therapist moving your arm to prevent it from getting stiff, but you’ll continue to wear the sling. Six weeks after surgery, you’ll stop wearing the sling and start working on moving your arm more in physical therapy and start light strengthening exercises. Twelve weeks after surgery, or three months, you’ll start to do more significant strengthening. It takes about five or six months to start feeling close to normal, and many people continue to see improvements for a year after surgery.
There are risk factors that affect the success of your surgery and increase the risk of the tendon not healing.
- Diabetes, especially with an A1C above 7
- Larger tears
- Older tears
- Narcotics before surgery
- Steroid injection within 6 months, especially more than two injections within a year
- Non-compliance with post-operative restrictions
If someone has a massive rotator cuff tear that is not repairable they will need a reverse shoulder replacement. In an anatomic shoulder replacement, or one that is like your natural shoulder, the ball is on your arm bone and the socket is on your shoulder blade and they are replaced by plastic and metal versions. However, an anatomic shoulder replacement requires a working rotator cuff. A reverse shoulder replacement puts the socket on your arm bone and the ball on your shoulder blade and does not need a working rotator cuff. You will still relieve the pain coming from the massive rotator cuff tear and/or arthritis and allow the shoulder to function well.
Frequently asked questions
Will small tears heal themselves?
No, rotator cuff tears do not heal themselves. Tears may become asymptomatic, which means not causing pain or problems using your arm. Sometimes our goal for treatment is making tears asymptomatic.
What are the chances of surgically repairing a minor tear that happened a while ago that was only treated with physical therapy?
Very often those tears can still be successfully treated with surgery. Generally small tears experience less atrophy than larger tears, so if it looks like the muscle still has good quality and the tendon hasn’t retracted very far, the tear can often be treated with surgery.
Are rotator cuff tears and frozen shoulder related?
You can have a rotator cuff tear and frozen shoulder at the same time but they are two separate conditions. Frozen shoulder is when the capsule around the shoulder, which is like a water balloon with joint fluid in it, gets inflamed and irritated and starts to thicken. As it gets thicker, it can be painful and can restrict your motion. The treatment for frozen shoulder is different than the treatment for rotator cuff tears.
What are some ways to make sleeping easier if you have a torn rotator cuff tendon?
Many people have found that sitting in a more upright position is helpful, with a pile of pillows on the bed or sleeping in a reclining chair. However, talk to your doctor as well because they will want to make sure they are addressing the baseline cause of the pain.