In this article, you will learn about the rotator cuff and signs and symptoms of common injuries that can occur in this complex area of the shoulder.
What is the Rotator Cuff?
The rotator cuff is a group of four major muscles, surrounded by tendons, that encompass the top of the arm bone. This covering of the upper humerus, or upper arm bone, provides support to the shoulder joint and permits arm rotation and elevation while keeping the humerus in place. The four rotator cuff muscles (supraspinatus, infraspinatus, teres minor and subscapularis), are all attached to the shoulder blade and work together to control shoulder motion.
Types of Rotator Cuff Injury
The rotator cuff can be damaged in a number of ways. Some injuries require simple rest and basic pain management, while others may require surgical intervention. The most common rotator cuff injuries are:
- rotator cuff bursitis
- rotator cuff tendinitis
- rotator cuff tear
According to the American Academy of Orthopedic Surgeons, women over the age of forty are the most likely to suffer a rotator cuff injury, but such injuries are also common in athletes. According to Drs. Matsen and Warme of The University of Washington Department of Orthopaedics and Sports Medicine, “Failure of the rotator cuff due to either tear or wear is the most common clinical problem of the shoulder, accounting for more than 4.5 million physician visits per year in the United States.”
Rotator Cuff Bursitis and Tendinitis
Repetitive, strenuous use of the shoulder joint can lead to rotator cuff bursitis. Bursitis in this area occurs in the subacromial bursa, the fluid filled sack in the shoulder joint that is designed to absorb shock and lubriacte movement. The bursa can become inflamed and rub up against the bony prominence at the top of the shoulder blade or one of the shoulder ligaments. This results in significant discomfort and swelling. Performing the same action over and over again, such as pitching a ball, weight lifting, or repetitive cleaning, is the most common cause of this type of injury. Symptoms of rotator cuff bursitis include:
- pain when the arm is raised overhead, or when reaching forward
- swelling and redness in shoulder tissues
Rotator cuff tendinitis is very similar to bursitis in its presentation and symptoms. The two conditions often occur together but can happen separately. Rotator cuff tendinitis occurs when the tendons of the shoulder joint become inflamed, due to overuse or overstress. Like rotator cuff bursitis, tendinitis can result from repetitive shoulder motion, but it can also be a result of a single, significant stress to a shoulder tendon. Signs of rotator cuff tendinitis include:
- pain with shoulder movement, particularly when the arm is raised
- swelling and redness
In the case of both rotator cuff bursitis and tendinitis, continued stress to the shoulder joint can lead to the more serious condition of shoulder impingement syndrome, which occurs when the space within the rotator cuff decreases as the tendon or bursa is pinched in the joint. Without treatment, tissue degeneration can result, which may ultimately lead to a rotator cuff tear.
Rotator Cuff Tears
Rotator cuff tears are the most serious type of rotator cuff injury. They occur when a tear opens up in a muscle or tendon as a result of either a traumatic incident to the shoulder, or weakness in the cuff due to chronic tendinitis or bursitis. Tears can be complete or partial, typically depending on the mechanism of injury. Partial tears result from repeated stress or irritation from bone spurs in the area. Complete tears are more likely to happen during an accident, such as lifting something too heavy or falling onto the joint, but they can also occur when a partial tear ultimately progresses. Tears can also happen alongside another shoulder injury, such as dislocation. Symptoms of a rotator cuff tear include:
- Moderate to severe pain when raising the arm or lowering the arm from a raised position
- Muscle wasting around the shoulder joint
- Bruising of the upper arm
- ‘Cracking’ noise with shoulder movement
- Significant weakness when attempting to move the arm, particularly in an upwards direction.
According to Mall, et al, in an article appearing in the November 2010 edition of the Journal of Bone and Joint Surgery, “Pain development is associated with tear size progression.” In a study of over forty patients who began with a rotator cuff injury that did not produce symptoms, two years after the injury “40% of partial-thickness tears progressed to full-thickness, and 18% of full-thickness tears increased by more than 5 mm.” This data supports the need for timely, effective treatment of rotator cuff injuries. Many can be addressed without surgery, if evaluated and treated promptly.
What to do if a Rotator Cuff Injury is Suspected
Rotator cuff injuries should not be ignored, as they can quickly progress in severity and magnitude. If such an injury occurs, seek the assistance of a primary care physician or go directly to an orthopedist. An MRI of the shoulder will likely be ordered to confirm rotator cuff involvement. Depending on the type and severity of injury, treatment may involve:
- steroid injections
- physical therapy
- surgical intervention.
See the following articles to learn more about rotator cuff injury treatment.
Image Credit: Ted Goldring, https://www.flickr.com/photos/tedgoldring/214691627/
Mall NA, Kim HM, Keener JD et al. “Symptomatic Progression of asymptomatic rotator cuff tears: a prospective study of clinical and sonographic variables_” The Journal of Bone and Joint Surgery._ November 2010_._
Matsen, Frederick and Warme, Winston. Surgery for Painful Shoulders and Shoulders Weakened by Rotator Cuff Tears. UW Orthopaedics and Sports Medicine.https://www.orthop.washington.edu/PatientCare/OurServices/ShoulderElbow/Articles/Surgeryforpainfulshouldersandshoulders.aspx