Helpful Information for All Our Patients

Each month in our "Tip of the Month" page we will provide our patients with helpful orthopedic and sports medicine topics. We encourage you to read through and contact our doctors with any further questions.

Definition

The rotator cuff is composed of four muscles: the supraspinatus, the infraspinatus, the sub-scapularis, and the teres minor muscles (Figure 1). These muscles form a cover around the head of the humerus whose function is to rotate the arm and stabilize the humeral head against the glenoid. Rotator cuff tears occur primarily in the supraspinatus tendon, which is weakened as a result of many factors, including injury, age, poor blood supply to the tendon, and sub-acromial impingement. This injury rarely affects people younger than age 40 years.

Clinical Symptoms

Patients often report recurrent shoulder pain for several months and can often pinpoint a specific injury that triggered the onset of the pain. Night pain is characteristic, and patients often report having difficulty sleeping on the affected side. Weakness, catching, and grating are common symptoms, especially when lifting the arm overhead.

Tests

Exam
Examination reveals that the top and the back of the shoulder may appear sunken, indicating atrophy of the supra-spinatus and infraspinatus muscles (Figure 2). This clinical appearance is common in long-standing rotator cuff tears. Passive range of motion of the shoulder is normal, but active range of motion is limited. Conversely, patients with a frozen shoulder have limited active and passive range of motion. As the patient lifts the arm, a "grating" sensation about the tip of the shoulder can be felt. Mild tenderness on palpation over the greater tuberosity is usually present as well.

With large tears, the patient can only shrug, or "hike," the shoulder when asked to lift the arm. There is a complete tear of the rotator cuff if the patient cannot hold the arm elevated when it is lifted parallel to the floor.

Diagnostic
With complete tears, AP radiographs reveal a high-riding humerus relative to the glenoid. A 20° angled view will often show a spur projecting down from the inferior surface of the acromion. A shoulder arthrogram remains the gold standard for confirming rotator cuff tears. This test is more cost-effective and as accurate as an MRI scan; however, an MRI scan should be ordered for patients who are allergic to iodine or seafood.

Differential Diagnosis

Bursitis-tendinitis with impingement

Cervical spondylosis (neck stiffness, absent biceps reflex, sensory changes)
Frozen shoulder or adhesive capsulitis (restricted active and passive motion)
Osteoarthritis of the acromioclavicular joint (radiographic evidence of arthritis)
Osteoarthritis of the glenohumeral joint (radiographic evidence of arthritis)
Pancoast tumor (venous distention, pulmonary changes or bony metastases)
Thoracic outlet syndrome (ulnar nerve paresthesias, worse with "military brace" position)

Adverse Outcomes of the Disease

Loss of shoulder motion, especially the ability to lift the arm overhead, chronic pain, and/or weakness in the affected arm are all possible.

Treatment

Conservative treatment includes NSAIDs, physical therapy with strengthening and stretching exercises, sub-acromial corticosteroid injections, and avoiding overhead activities. Corticosteroid injections are controversial, as there is no evidence that they help the tendon to heal. While corticosteroids do relieve pain in the short term, repeated injections tend to weaken the tendon and may ultimately lead to the need for surgical repair. Therefore, patients should not receive more than three subacromial injections.

Complete cuff tears require surgery. Just as the ends of a rubber band stretched between two sticks will retract when cut, so, too, Will a torn rotator cuff retract when the tendon is ruptured. However, not all patients have severe enough symptoms that they want to undergo surgery. Patients with acute rotator cuff tears tend to do better if they undergo surgery within 6 weeks of the time of the injury.

Adverse Outcomes of Treatment

NSAIDs may cause gastric, renal, or hepatic complications. Corticosteroid injections can result in transient increase in pain due to the injection itself and/or degeneration of cuff tissue.

Referral decisions/Red flags

Failure of conservative treatment after 3 to 4 weeks and a positive shoulder arthrogram are indications for further evaluation.