Rotator Cuff Injury: A Common Cause of Shoulder Pain

Shawn P. Johnston, MD, Alaska Spine Institute

The rotator cuff is a group of four muscles that attach the upper arm bone (humerus) to the shoulder blade (scapula). These muscles help guide the shoulder through many motions and provide dynamic stability to the shoulder joint.

Injury can occur with repetitive overhead activities (such as are common among athletes and workers) as well as traumatic events such as falling on an outstretched arm.

Injury of the rotator can occur in both young and old. In younger individuals, there is either a sudden trauma or significant overhead repetitive use. As people age, the tissues of the rotator cuff lose some elasticity and become more susceptible to injury. Injuries in older individuals, therefore, can occur with less forceful and repetitive injuries and often occur while performing everyday activities.

The most common symptom of a rotator cuff tear is pain. This pain is often difficult for a patient to localize to a specific area of the shoulder and is described as a generalized discomfort that is worse with specific movements of the shoulder (especially overhead). Frequently, the pain seems to be worse at night, and often interrupts sleep. Loss of motion about the shoulder can also occur, and usually is more common with larger, complete rotator cuff tears.

The diagnosis of a rotator cuff tear is suspected based on the history and physical examination and often confirmed by an imaging study. Most commonly, an magnetic resonance imaging (MRI) of the shoulder is performed. However, an arthrogram, plain x-rays or an ultrasound are sometimes an alternative to the cost of an MRI. The benefit of MRI over the other studies is that it can show the tendons, cartilage and other soft tissues in great detail. This allows identification of tears of the rotator cuff, as well as other problems such as tendonitis (inflammation of the tendon) or bursitis (inflammation of the bursa).

In general, rotator cuff tears do not heal well with time. They tend to either enlarge, or, at best stabilize in size. That said, the first step in rotator cuff treatment is usually with conservative measures. While the size of the tear may not change with conservative treatment, the symptoms often diminish. These conservative treatments are also used for tendonitis and bursitis. Treatment is usually based on the type of injury and the need for pain relief, movement and function. In most cases, the initial treatment is non-surgical and involves several modalities.

A supervised physical therapy program is the mainstay of this non-surgical treatment. The first phase of therapy is to reduce rotator cuff inflammation and pain as well as improve range of motion. Rest from the inciting activity is often prescribed, as is the use of ice and short-term use of non-steroidal anti-inflammatory medications. If these options are ineffective at alleviating the pain, a cortisone injection can be considered. Once the pain is reduced, a physical therapy program that involves stretching and strengthening of the shoulder muscles begins. Conservative measures may not be effective in all patients. If conservative treatments fail or the patient is not a candidate for conservative treatments surgery may be an option for treatment.