The shoulder joint is a ball and socket type joint. The top part of the arm bone (humerus) forms a joint with the shoulder blade (scapula). The rotator cuff holds the head of the humerus into the scapula. It also controls movement of the shoulder joint.
The tendons of the rotator cuff pass underneath a bony area on their way to attaching the top part of the arm bone. When these tendons become inflamed, they can become frayed over this area during shoulder movements. Sometimes, a bone spur narrows the space even more.
Rotator cuff tendinitis is also called impingement syndrome. Causes of this condition include:
Keeping the arm in the same position for long periods, such as doing computer work or hairstyling
Sleeping on the same arm each night
Playing sports requiring the arm to be moved overhead repeatedly such as in tennis, baseball (particularly pitching), swimming, and lifting weights overhead
Working with the arm overhead for many hours or days, such as in painting and carpentry
Poor posture over many years
Rotator cuff tears may occur in two ways:
A sudden, acute tear may happen when you fall on your arm while it is stretched out. Or it can occur after a sudden, jerking motion when you try to lift something heavy.
A chronic tear of the rotator cuff tendon occurs slowly over time. It is more likely when you have chronic tendinitis or impingement syndrome. At some point, the tendon wears down and tears.
There are two types of rotator cuff tears:
A partial tear occurs when a tear does not completely sever the attachments to the bone.
A complete, full thickness tear means that the tear goes all the way through the tendon. It may be as small as a pinpoint, or the tear may involve the entire muscle tendon. With complete tears, the tendon has come off (detached) from where it was attached to the bone. This kind of tear does not heal on its own.
Early on, pain is mild and occurs with overhead activities and lifting your arm to the side. Activities include brushing your hair, reaching for objects on shelves, or playing an overhead sport.
Pain is more likely in the front of the shoulder and may travel to the side of the arm. The pain always stops before the elbow. If the pain goes down the arm to the elbow and hand, this may indicate a pinched nerve.
There may also be pain with lowering the shoulder from a raised position.
Over time, pain may be present at rest or at night, such as when lying on the affected shoulder. You may have weakness and loss of motion when raising the arm above your head. Your shoulder can feel stiff with lifting or movement. It may become more difficult to place the arm behind your back.
ROTATOR CUFF TEARS
The pain with a sudden tear after a fall or injury is usually intense. Right after the injury, you likely have weakness of the shoulder and arm. You may also feel a snapping sensation when trying to move the arm.
With a chronic tear, you often do not notice when it began. This is because symptoms of pain, weakness, and stiffness or loss of motion worsen slowly over time.
Most people with rotator cuff tendon tears have pain at night. Pain that is worse at night may wake the person. During the day, the pain is more tolerable, and usually only hurts with certain movements.
Over time, the symptoms become much worse, and are not relieved by medicines, rest, or exercise.
Exams and Tests
A physical examination may reveal tenderness over the shoulder. Pain may occur when the shoulder is raised overhead. There is usually weakness of the shoulder when it is placed in certain positions.
X-rays of the shoulder may show a bone spur.
Your doctor may order other tests:
An ultrasound test uses sound waves to create an image of the shoulder joint. It can show a tear in the rotator cuff.
With a joint x-ray (arthrogram), the doctor injects contrast material (dye) into the shoulder joint. Then an x-ray, CT scan, or MRI scan are used to take a picture of it. Contrast is usually used when your doctor suspects a small rotator cuff tear.
Medicine (corticosteroid) injected into the shoulder to reduce pain and swelling
Surgery (arthroscopy) to remove inflamed tissue and part of the bone over the rotator cuff to relieve pressure on the tendons
Rest and physical therapy may help with a partial tear if you do not normally place a lot of demand on your shoulder.
Surgery to repair the tendon may be needed if the rotator cuff has a complete tear. Surgery may also be needed if the symptoms do not get better with other treatment. Most of the time, arthroscopic surgery can be used. Large tears may need open surgery, surgery with a larger incision, to repair the torn tendon.
With rotator cuff tendinitis, rest, exercise and other self-care measures often improve or even relieve symptoms. This may take weeks or months. Some persons may need to change or reduce the amount of time they play certain sports to remain pain-free.
With rotator cuff tears, treatment often relieves symptoms. But outcome depends on the size of the tear and how long the tear has been present, the person's age, how active the person was before the injury.
When to Contact a Medical Professional
Call for an appointment with your health care provider if you have ongoing shoulder pain. Also call if symptoms do not improve with treatment.
Avoid repetitive overhead movements. Exercises to strengthen shoulder and arm muscles can also help prevent rotator cuff problems.
C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.