Rotator cuff tears are a common cause of pain and disability among adults. Most tears occur in the supraspinatus muscle, but other parts of the cuff may be involved. 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
- Crackling sensation (crepitus) when moving the shoulder in certain positions
Symptoms can develop immediately after 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. In general, pain is felt in the front of the shoulder and may travel down the side of the arm. Pain may be mild initially and progress over time to affect the person at rest or with no activity at all. There may be pain when lying on the involved side and at night affecting sleep habits.
The rotator cuff consists of four muscles and tendons that cover the top of the upper arm bone (humeral head). The rotator cuff compresses the humeral head into the socket (glenoid) and enables the arm to elevate and rotate. The four muscles of the cuff include the supraspinatus, infraspinatus, subscapularis, and teres minor muscles and are attached to the scapula on the back through a single tendon unit. The subscapularis is the only muscle that attaches to the front of the shoulder (lesser tuberosity). The remaining muscles attach to the greater tuberosity (Figure 1).
Causes of rotator cuff tears
The rotator cuff can tear from a single traumatic event. People may report recurrent shoulder pain for several months and a specific injury that triggered the onset of the pain. A rotator cuff tear can occur in the setting of another injury to the shoulder, such as a dislocation and/or fracture of the humerus. The majority of tears occur from overuse of these muscles and tendons over a period of several years. People who are especially at risk for overuse are those who engage in repetitive overhead motions such as overhead athletes (baseball, tennis, weight lifting) and manual laborers (roofers, carpenters, car mechanics). Rotator cuff tears occur most commonly in people who are over the age of 40.
Diagnosis of a rotator cuff tear is based on history, symptoms, and physical examination. X-rays are initially performed to evaluate the shoulder joint and to rule out other issues such as arthritis. Further imaging studies, such as MRI (magnetic resonance imaging) and ultrasound are often obtained to confirm the tear and for surgical planning purposes (Figure 2). Shoulder pain may be a result of other problems such as a "pinched nerve" in the neck, requiring additional studies, such as spine x-rays, MRI, and electro-diagnostic studies.
Nonsurgical treatment may result in pain relief and improved function of the shoulder.
Nonsurgical treatment options include:
- Rest and restricted overhead activity
- Temporary use of a sling
- Anti-inflammatory medication
- Steroid injections
- Physical therapy
Surgery may be recommended if:
- Nonsurgical treatment does not relieve symptoms
- The tear is acute and symptomatic
- The tear is in the shoulder of the dominant arm of an active person
- If maximum strength in the arm is needed for overhead work or sports
The type of surgery performed depends on the size, shape, and location of the tear. A partial tear may require only a trimming procedure, called a " debridement. " A complete tear is repaired by either suturing the two sides of the tendon back together or from where the tendon inserts into the bone of the arm (humerus). The three general methods for surgery involve arthroscopic, "mini-open" and "open" procedures. As the arthroscopic method has evolved, many surgical repairs that were performed as inpatient procedures can now be done on an outpatient basis.
Postoperatively, the shoulder is immobilized in a sling or similar device to allow the tear to heal. The length of immobilization partially depends upon the severity of the tear. After 4 to 6 weeks of immobilization, the therapy program begins with passive motion such as pendulum and pulley exercises. By weeks 8 to 12, the program shifts to active and resistive training exercises. Complete recovery may take four to six months.
- A strong commitment to rehabilitation is important to achieve a good surgical outcome. The doctor will determine when it is safe to return to overhead work and sports activity.