Rotator Cuff Tears

Rotator cuff tears are a common source of shoulder pain. The incidence of rotator cuff damage increases with age and is most frequently caused by degeneration of the tendon, rather than injury from sports or trauma.

Anatomy

The rotator cuff is a group of four muscles that surround the humeral head (ball of the shoulder joint). The muscles are referred to as the "SITS" muscles: supraspinatus, infraspinatus, teres minor, and subcapularis. The muscles function to provide rotation, elevate the arm, and give stability to the shoulder joint (glenohumeral joint). The supraspinatus is most frequently involved in degenerative tears of the rotator cuff. More than one tendon can be involved. There is a bursa (sac) between the rotator cuff and acromion that allows the muscles to glide freely when moving. When rotator cuff tendons are injured or damaged, this bursa often becomes inflamed and painful.

Pain, loss of motion, and weakness may occur when one of the rotator cuff tendons tears. The tendons generally tear off at their insertion (attachment) onto the humeral head.

Cause

The rotator cuff can be torn from a single traumatic injury. Patients often report recurrent shoulder pain for several months and a specific injury that triggered the onset of the pain. A cuff tear may also happen at the same time as another injury to the shoulder, such as a fracture or dislocation.

Most tears, however, are the result of overuse of these muscles and tendons over a period of years. People who are especially at risk for overuse are those who engage in repetitive overhead motions. These include participants in sports such as baseball, tennis, weight lifting, and rowing.

Rotator cuff tears are most common in people who are over the age of 40. The blood supply to the rotator cuff diminishes with age and transiently with certain motions and activities.  The substance of the tendon itself degenerates over time. Because of the decrease in tendon blood supply, the body's ability to repair tendon damage is decreased with age; this can ultimately lead to a full-thickness tear of the rotator cuff.

Rotator cuff tear may often happen as a result of wear and tear. An extrinsic factor that can cause damage to the rotator cuff is the presence of bones spurs underneath the acromion. The spurs rub on the tendon when the arm is elevated; this is often referred to asimpingement syndrome. Combining this with a diminished blood supply, the tendons have a limited ability to heal themselves. These factors are at least partly responsible for the age-related increase in rotator cuff disease and the higher frequency in the dominant arm.

Younger people tend to have rotator cuff tears following acute trauma or repetitive overhead work or sports activity.

Symptoms

Some of the signs of a rotator cuff tear include:

• Atrophy or thinning of the muscles about the shoulder
• Pain when lifting the arm
• Pain when lowering the arm from a fully raised position
• Weakness when lifting or rotating the arm
• Crepitus or crackling sensation when moving the shoulder in certain positions

Symptoms of a rotator cuff tear may develop right away after a trauma, such as a lifting injury or a fall on the affected arm. When the tear occurs with an injury, there may be sudden acute pain, a snapping sensation and an immediate weakness of the arm. Symptoms may also develop gradually with repetitive overhead activity or following long-term wear. Pain in the front of the shoulder radiates down the side of the arm. At first, the pain may be mild and only present with overhead activities, such as reaching or lifting. It may be relieved by over-the-counter medication such as aspirin or ibuprofen.

Over time the pain may become noticeable at rest or with no activity at all. There may be pain when lying on the affected side and at night.

Diagnosis

Diagnosis of a rotator cuff tear is based on the symptoms and physical examination. X-rays, and imaging studies, such as MRI  or ultrasound, are also helpful.

Physical examination includes looking for any tenderness or deformity including the Impingement sign . Range of motion of the shoulder is measured in several different directions and the strength of the arm is tested . We also check for instability or other problems with the shoulder joint.

We will also examine the neck to make sure that the pain is not coming from a " pinched nerve " in the cervical spine and to rule out other conditions, such as osteoarthritis or rheumatoid arthritis.

Plain X-rays of a shoulder with a rotator cuff tear are usually normal or show a small spur. For this reason , an MRI may be required to better visualize soft tissue structures such as the rotator cuff tendon .The MRI can tell how large the tear is, as well as its location within the tendon itself or where the tendon attaches to bone.

Many surgical repairs can be done on an outpatient basis.

Surgical Procedure

Open Repair

Open repair is performed without arthroscopy. We make an incision over the shoulder and detach the deltoid muscle to gain access to and improve visualization of the torn rotator cuff . We will usually perform an acromioplasty (removal of bone spurs from the undersurface of the acromion) as well. The incision is typically several centimeters long. Open repair was the first technique used to repair a torn rotator cuff; over the years, the introduction of new technology and improved surgeon experience has led to the development of less invasive surgical procedures. Although a less invasive procedure may be attractive to many patients, open repair does restore function, reduce pain, and is durable in terms of long-term relief of symptoms.