Rotator Cuff Injuries

Anatomy

The rotator cuff is the name given to the four muscles (supraspinatus, infraspinatus, teres minor and subscapularis) that provide strength and extensive motion to the shoulder.  Unlike the deep, stable ball and socket joint at the hip, the main shoulder joint, called the glenohumeral joint, is a more shallow arrangement that is designed to maximize mobility.  The muscles of the rotator cuff therefore provide much of the joint’s stability, as well.

The rotator cuff is covered and protected by a sac, or bursa, that allows the rotator cuff tendons to glide freely beneath the acromion, which is a bone of the shoulder and an extension of the scapula, or shoulder blade.

Injury Types

Rotator cuff injuries are a common source of shoulder pain in many age groups.  These injuries can involve any type of irritation or damage to the tissues of the rotator cuff muscles or tendons.  These problems range widely from mild tendinitis and bursitis that often go away spontaneously to large tears of the rotator cuff that need surgical treatment.

Bursitis is produced when the bursa becomes inflamed, usually due to injury to the rotator cuff underlying it (see subacromial bursitis).  This can lead to shoulder pain and decreased motion.  Alternately, thickening of the bursa and rotator cuff can cause pain or damage to the rotator cuff when the thickened tissues become pinched beneath the acromion with shoulder motion (see shoulder impingement).

Causes

Rotator cuff injuries may result from a variety of causes, including degeneration or wear and tear of rotator cuff tissues, repetitive overhead motions, heavy or improper overhead lifting, poor posture (stooped, rounded shoulders) or trauma, such as falls. 

Most injuries involve degeneration or aging of the rotator cuff.  Other risk factors include weak shoulder musculature, athletic activities, such as swimming, tennis or baseball pitching and jobs that require repetitive overhead work, such as carpentry, painting or plumbing.

Symptoms

Pain is the most common symptom with these disorders.  Pain can occur at rest or with local pressure when lying on the affected side.  Often, pain is produced with attempted arm elevation, overhead activities or rotation, as when reaching into a pants pocket or behind your back.  Other symptoms include loss of shoulder motion, local tenderness to the touch or weakness, particularly if the rotator cuff is torn.  Not all tears of the rotator cuff will cause pain.  It is possible to have rotator cuff injury and have no symptoms at all.

Diagnosis  

History and physical examination are essential to the diagnosis and help to exclude other potential causes of pain that may be referred to the shoulder.  Physical exam maneuvers can help to identify shoulder impingement, bursitis or rotator cuff weakness.

X-ray studies of the shoulder can suggest rotator cuff problems, particularly when degeneration of the cuff is advanced and is accompanied by arthritic changes in the bones around the shoulder.  Diagnostic ultrasound can be helpful in making the diagnosis, but is very dependent on the skill of the person conducting the study.

MRI gives the most detailed look at the rotator cuff tissues and has become the gold standard for diagnosing rotator cuff injuries.

Treatment

Unless a rotator cuff tear is large, the shoulder is unstable, or the patient is a throwing athlete who needs to return to competition as soon as possible, non-surgical methods of treatment should be the preferred method of treatment.

The rehabilitation of rotator cuff injuries usually proceeds in phases.  The acute phase is focused on pain control and the reduction of inflammation.  This is achieved through the use of ice, anti-inflammatory medications, relative rest and the avoidance of movements that provoke pain.  The goal is to permit healing and allow the patient to begin an active rehabilitation program that begins to restore strength and range of motion to the shoulder.  Physical therapy is critical to this effort.  Corticosteroid injections of the shoulder can aid this process.

In the recovery phase, physical therapy is utilized to restore range of motion and normal movement patterns, joint stability and position sense.  When pain has resolved, strengthening can proceed.

The maintenance phase of rehabilitation utilizes physical therapy to help patients return to job and sports-specific activities.  Home exercises, which were begun in the early stages of rehabilitation are consolidated to those few core exercises that help to decrease the risk for symptom recurrence over time.

If medically supervised rehabilitation treatment does not relieve pain or restore function sufficiently to permit a return to work or leisure activities, surgery should be considered.  Early repair of rotator cuff tears, particularly when large or full-thickness in nature, serve to prevent fatty degeneration and retraction of the intact remaining rotator cuff tissues.  Post-surgical rehabilitation treatments should be focused on functional recovery.