Rotator Cuff Tears

The shoulder is a ball and socket joint. The socket (called the glenoid) is on the shoulder blade (scapula), and the ball is on the top of the upper arm bone (humerus). The rotator cuff consists of four muscles and their tendons that connect the scapula to the humerus. The rotator cuff works together to provide shoulder stability and facilitate shoulder movement. These tendons are essential to be able to lift and rotate the arm.

A rotator cuff tear occurs when one or more of the tendons of the rotator cuff muscles are torn. These tears can be partial (in which some of the tendon fibers are damaged, but the tendon is not completely detached) or full-thickness (in which the tendon is completely detached from the bone). Rotator cuff tears can lead to significant discomfort, weakness, and functional impairment in the affected shoulder.

• Acute tears: These tears occur suddenly after a specific injury, such as falling on an outstretched arm, lifting something heavy, or experiencing a direct blow to the shoulder.
• Chronic tears: Repeated shoulder use, especially in activities requiring overhead motion (such as painting, swimming, or throwing), can cause microtrauma or tiny tears in the rotator cuff tendons, which can enlarge over time. Poor mechanics and muscle imbalances in athletes can also cause a rotator cuff tear. With aging, tears of the rotator cuff can occur due to wear and tear over a lifetime and limited blood supply to the tendon, which limits its ability to heal independently. It is important to note that tears are very common in those aged 60 and over and do not always cause symptoms.

• There is pain and discomfort when performing overhead motions such as reaching upwards and throwing. Pain at night is also common with rotator cuff tears.
• Limited active range of motion of the shoulder.
• Pain or weakness with lifting, especially overhead. Decreased sports performance, such as a noticeable decline in throwing velocity or serve speed.

The intensity of these symptoms can range from mild discomfort to severe pain and complete loss of function. Notably, some individuals may experience a rotator cuff tear without significant pain but might notice progressive weakness and loss of shoulder function.

Diagnosing a rotator cuff tear involves a combination of clinical evaluation and imaging studies. Your UCSF Women’s Sports Medicine specialist will review your medical history and inquire about your symptoms, your history of shoulder injuries, and activities that aggravate your pain. They will perform a thorough examination employing tests to assess the strength of the rotator cuff muscles and the shoulder’s range of motion.

X-rays will be ordered to assess the shoulder’s alignment and the bones’ shape, which may suggest a chronic rotator cuff tear. An ultrasound may be ordered to visualize soft tissue structures and assess the integrity of the rotator cuff tendons, including the presence and extent of a tear. MRI provides detailed images of bone and soft tissues, including the muscles and tendons of the rotator cuff. It is particularly useful for identifying the size and specific location of the tear, as well as the health of the rotator cuff muscle.