Rotator Cuff Injuries
The rotator cuff is what keeps your arm bone in the shoulder socket. It’s formed by the tendons of four muscles that connect the humerus (upper arm bone) to the scapula (shoulder blade). The rotator cuff makes it possible for you to raise, lower, and rotate your arm.
The rotator cuff tendons are key to the healthy functioning of the shoulder. But they’re also used a lot. Every time you lift or move your arm, your rotator cuff is at work. Over time the rotator cuff can become painful. This type of shoulder pain could be caused by several conditions such as:
- Rotator Cuff Tendonitis
- Rotator Cuff Tear
Tearing the rotator cuff tendons is an especially painful injury that most often isn’t caused by a single injury or event. It’s an injury that usually takes place over time, weakening the shoulder.
Most of the time, patients with torn rotator cuffs are in late middle age. But rotator cuffs tears can happen at any age, especially if you’re using your shoulder a lot in a sport such as pitching, or tennis or in your job for overhead work.
Rotator cuff tears can either be partial (incomplete) or full (complete). Partial tears damage the tendon, but do not completely sever it. Full tears, on the other hand, are a complete separation of the tendon from the bone.
Rotator Cuff Tear Causes
Injury and degeneration are the two main causes of rotator cuff tears.
Acute Rotator Cuff Tear
Excessive force can tear weak rotator cuff tendons. This force can come from trying to catch a heavy falling object or lifting an extremely heavy object with the arm extended. The force can also be from a fall directly onto the shoulder. Sometimes injuries that tear the rotator cuff are painful, but sometimes they aren't. Researchers estimate that up to 40 percent of people may have a mild rotator cuff tear without even knowing it.
You should schedule an appointment with an orthopedic specialist if you have pain after a sudden impact or event.
Degenerative Rotator Cuff Tear
Most tears are the result of the constant use of the tendons over time. This degeneration naturally occurs as we age. Two main factors that contribute to rotator cuff degeneration are low blood supply and repetitive stress.
- Low blood supply. The rotator cuff tendons have areas of very low blood supply. The more blood supply a tissue has, the better and faster it can repair and maintain itself. The areas of poor blood supply in the rotator cuff make these tendons especially vulnerable to degeneration from aging. The degeneration of aging helps explain why the rotator cuff tear is such a common injury later in life. Rotator cuff tears usually occur in areas of the tendon that had low blood supply to begin with and then were further weakened by degeneration.
- Repetitive stress. Repetitive stress refers to the repeating of the same types of shoulder motions over and over again. This can happen with overhand athletes, such as baseball pitchers. But even doing routine chores like cleaning windows, washing and waxing cars, or painting can cause the rotator cuff to fatigue from overuse. When you begin feeling pain in the shoulder you should give yourself several days of rest from that activity to see if the pain is reduced.
Rotator Cuff Injury Symptoms
The most common symptoms of a rotator cuff tear can include:
- Pain and weakness in the affected shoulder. In general, the larger the tear, the more weakness it causes. Partial tears still allow movement of the arm, but full tears make it almost impossible to raise the arm away from your side.
- Crackling sensation (called crepitus) when moving your shoulder in certain positions. Crepitus can be the result of rough joint surfaces moving against each other, the “snapping” of tendons or ligaments against the bony structures of the joint, or by the abnormal presence of air bubbles within the shoulder tissue that “pop” inside the joint. Sounds associated with crepitus can either be muffled or loud enough for other people to hear.
The amount of pain, weakness, or other symptoms experienced often depends on how serious the tear is (partial or full).
In order to properly diagnose a rotator cuff tear, it is best to see an orthopedic specialist who will perform a thorough physical examination of your shoulder. In addition to diagnosing the condition, an orthopedic specialist can plan the best nonsurgical or surgical treatment options for you. A complete tear is usually very obvious. If your doctor can move the arm in a normal range of motion, but you can't move the arm yourself, you most likely have a torn rotator cuff. Diagnosis may also include MRI or other imaging tests. These tests can also determine whether the tear is full or partial.