The shoulder joint is unique among the large joints of the human body. It's the most moveable, and one of the most fragile, joints we have. For the most part, its flexibility enables our arms to be extremely useful.

  To discuss the painful shoulder, let's understand how the normal shoulder anatomy is put together first. The shoulder joint consists of three bones held together by muscles, tendons and ligaments. The clavicle (collarbone) attaches the shoulder to the rib cage and holds the shoulder out from your body. It connects with a large flat scapula (shoulder blade) at the acromion (top of the shoulder). The bones of the shoulder and the attaching ligaments form a ball-and-socket joint--better known as the shoulder joint.

  The shoulder joint is stabilized by the rotator cuff, a commonly known group of tendons that attach the shoulder to your back and chest muscles. Between the top of the shoulder and the rotator cuff lies the bursa, a small sac containing fluid to buffer friction between the tendon and the bone.

  What's important is that the shoulder affords us the ability to move our arms many ways. However, because of this ability the shoulder is also the least stable joint and most likely to develop problems.

  The shoulder is often the cause of much dysfunction and ongoing pain. Commonly, people think this pain is the result of arthritis. Although the symptoms can resemble those of arthritis, whether you are 29 or 89 it is more likely that the pain and dysfunction are a result of a process called shoulder impingement syndrome. Of course, there are exceptions, as in patients who have a history of rheumatoid arthritis or trauma of the shoulder, such as from an accident.

Causes and Symptoms

   Every time the arm is held out from the body in any direction, the rotator cuff and the bursa sac in the shoulder are squeezed. Over the years, too much of this friction can wear down the tendon and the bursa. This can lead to inflammation of the bursa and the rotator cuff and the development of bony spurs, eventually causing a tearing of this supportive cuff. Other causes of impingement syndrome include mechanical alterations of the shoulder and its surrounding structures.

  There are four stages of shoulder impingement syndrome. Stage 1, typically seen in younger patients (25-30 years of age), is caused by overuse and is a reversible process of tendon swelling and hemorrhage (tendinitis). In Stage 2, which usually occurs in patients up to 40 years old, changes include fibrosis and a thickening of the (subacromial) bursa. In Stage 3, usually seen in the older age group or associated with significant disease or injury, there is typically a tear (partial or complete) of the tendons that connect the rotator cuff and the head of the biceps muscle, and there also can possibly be some bone irregularities. Stage 4 is end-stage arthritis with a complete rotator cuff tear.

  Patients with a history of repetitive overuse, such as baseball players, may suffer microtrauma, may develop a fibrosis or inflammation of the lining between the cuff and top of the shoulder leading to a chronic bursitis or tendinitis. Remember, the diagnosis given as "bursitis" (inflammation of the bursa) is really a symptom of an underlying problem.

  Severity of the symptoms of these stages can vary depending upon the degree of the problem. Pain can be a dull ache in the shoulder but can become a sharp pain when trying to move the arm, particularly overhead. The pain may be worse at night, and you may have sleep difficulties as well.

  For each patient presenting with shoulder pain, it is necessary for the physician to obtain a complete history and physical examination. During your physical examination, the doctor will check for pain, tenderness and loss of motion. Sounds of popping, grinding or clicking can be key components of the problem, too.

  Other conditions that could be identified during this visit include cervical disc disease (neck), systemic arthritis, nervous system disorders and tumors, to name a few.

  To accurately identify the problem and to determine the severity of the impingement syndrome, it is also sometimes necessary to order an arthrogram (where dye is injected into the joint to outline the soft structures), an MRI scan of the shoulder, x-rays of the neck area, or chest or nerve studies.

  Once the diagnosis of impingement syndrome is made and the stage is determined, a treatment program is designed. Initial treatment is usually conservative. Depending on the patient's response to the program, treatment can become more aggressive if it's appropriate to the patient's needs. In Stage 1, heat and rest should be utilized. Ice is appropriate after an acute flare of symptoms typically seen after overuse. Examples include a young person throwing a ball repetitively, a middle-aged weekend athlete or a senior adult who decided to patch up his roof.

  Use of non-steroidal anti-inflammatory drugs for acute flares can be extremely useful. Physical therapy including progressive stretching and strengthening exercises is utilized until the patient has recovered. Rotator cuff strengthening must be done to prevent Stage 1 or 2 from advancing to a more severe stage. A maintenance program is recommended in most cases depending on the patient's symptoms after initial treatment.

  In stages 2 and 3, impingement syndrome can necessitate surgical intervention. The role of cortisone injections is somewhat controversial, because steroid injections can have the side effect of weakening the same tendon we are trying to protect and preserve with therapy or surgery. Cortisone can be used at infrequent intervals in appropriately selected patients. However, if the symptoms aren't alleviated or if pain persists, the surgical correction of impingement syndrome may be best in the long run.

Surgical Intervention

   There are a number of surgical techniques that offer relief for shoulder impingement syndrome. Arthroscopic surgery, which is relatively non-invasive, permits the surgeon easy access and excellent viewing of the joint and the surrounding tissues. With this technique, it is possible to clean out any of the fibrosis and thickened tissue. Small rotator cuff tears can be repaired and small bone irregularities (spurs) can be removed.

  Severe rotator cuff tears require a more invasive surgical procedure. Because of the differences in the application of these two surgeries, one can easily realize the value of an early diagnosis and treatment program. Early intervention can help you to avoid a more serious surgery later on.

  Following surgery, the patient returns to a physical therapy program with the same basic goals--maintenance of pain relief, return of range of motion and ultimately a stronger and more useful shoulder.

  The earlier the intervention the more likely it is to provide long-term function and pain relief. In fact, if a nagging shoulder problem does exist, it's possible ongoing damage is occurring, which will progressively become more severe and debilitating. Proper diagnosis, treatment and strength maintenance of the shoulder can improve or alleviate the shoulder problem and return you to a more active lifestyle.

The Stages of Shoulder Impingement Syndrome

Stage 1

Edema and Hemorrhage (Bursitis)
Common Age: 20s
Symptoms: Pain and soreness from overuse
Clinical Course: Reversible
Treatment: Conservative

Stage 2

Fibrosis and Tendinitis (Tendinitis)
Common Age: Up to 40
Symptoms: Pain with vigorous use above horizontal
Clinical Course: Recurrent pain with activity
Treatment: Conservative/surgical

Stage 3

Bone Spurs and Rotator Cuff Tears
Common Age: Older adults
Symptoms: Pain at top of shoulder/upper arm, weakness, inability to use arm effectively
Clinical Course: Progressive disability, can be chronic
Treatment: Surgical arthroscopy

Stage 4

Rotator Cuff Arthropathy
Common Age: Older adults
Symptoms: Severe pain with motion, inability to use arm
Clinical Course: Progressive disability
Treatment: Open surgery; may require joint replacement

About the author:
Leonard Bodell, M.D., is a board-certified, Mayo-trained upper-extremity orthopaedic surgeon. Dr. Bodell is highly recognized for his expertise and experience in hand and upper-extremity surgery as well as pain management. He is associated with Associates in Hand and Plastic Surgery in metro Phoenix, Arizona.

© Copyright 2005. Arthritis Education by Professionals, Inc.