Shoulder Injuries-Overuse to Trauma: Part 2

Part 2—Traumatic Shoulder Injuries
Last week, common overuse conditions of the shoulder were described along with their treatment. This week’s Health Tip describes common shoulder conditions that develop as a result of trauma. First let’s review the anatomy of the shoulder. The shoulder is made up of three bones: the upper arm bone (humerus), the shoulder blade (scapula), and the collarbone (clavicle). The head of the humerus fits into a curved socket, called the glenoid, which is part of the shoulder blade. A group of muscles and tendons, known collectively as the rotator cuff, keep the arm bone centered in the shoulder socket and allow for movement in many different directions.
In contrast to the overuse conditions discussed in last week’s Health Tip, the injuries described above sometimes require surgery to restore function and/or relieve pain.

• Rotator Cuff Tears--- One of the most serious shoulder injuries involving soft tissue (muscle, tendon, ligament, etc.) is a rotator cuff tear. These may occur suddenly (acute tears) or slowly over time (chronic tears). Acute tears usually occur from a sudden jerk, as when lifting a heavy object, or from falling on an outstretched arm. Chronic tears occur most commonly in someone with longstanding “wear and tear” (degenerative) changes in rotator cuff. The primary symptoms of a rotator cuff tear are: 1) pain and weakness in the shoulder and 2) difficulty moving the shoulder, especially with overhead movements. In roughly half of people with rotator cuff tears, non-surgical treatment involving activity modification, anti-inflammatory medication, and physical therapy will restore the individual to an acceptable level of activity. If the cuff has torn completely, or the tear results in persistent pain, surgery to reattach the torn tendon back to bone may be necessary. The surgery can often be done as an outpatient, although several months of rehabilitation are usually required to regain full strength and mobility.
  
  
• Instability---Shoulder instability occurs when the structures that stabilize the shoulder joint fail to keep the ball of the upper arm bone tightly within its socket. In a shoulder dislocation, the head of the humerus comes completely out of its socket. When the head comes only part way out of the socket, it’s known as subluxation. Initial episodes of instability usually occur as a result of an injury. Severe pain and inability to move the shoulder are typically present following an acute dislocation. If the ligaments, tendons and muscles supporting the shoulder become stretched or damaged following the initial episode, chronic instability with recurrent dislocations may occur. With the first dislocation, physical therapy directed at strengthening the shoulder stabilizers is usually the best course of treatment. If the shoulder joint is so lax that repeated dislocations occur, surgery may be necessary to repair torn or stretched ligaments.
  
  
• Acromioclavicular Joint Sprain. The acromioclavicular (A-C) joint is located where the clavicle (collar bone) connects with a portion of the scapula known as the acromion. Its location is at the tip or highest point of the shoulder. The two bones forming the A-C joint are held together by ligaments. An A-C joint sprain occurs when these ligaments are stretched or torn. The common name for this injury is “shoulder separation”. A-C joint sprains and can range from a mild stretching of the ligaments that hold the joint together (Grade 1) to a complete tear of the ligaments (Grade 3-4 sprain). This injury occurs most often when someone falls directly on the point of the shoulder. Measures to reduce pain (sling, cold packs, and pain medication) along with time for healing are usually all that is required in mild sprains. When a complete tear of the A-C joint ligaments causes persistent pain or significant deformity, surgery to repair the damaged ligaments may be necessary.
  
  
• Fractures---The clavicle (collar bone) is the most commonly fractured shoulder bone. This fracture is seen most often in younger individuals, often due to landing on the shoulder as could occur during a bicycle crash. Fractures of the upper part of the arm (humerus) occur more often in older (65 years of age or older) individuals as a result of falling. The scapula is fractured less commonly that the other two bones of the shoulder and is usually the result of high-energy trauma, such as a motor vehicle accident. With each of these fractures, as long as the bone fragments are not shifted out of position (displaced), healing can occur without the need for surgery. Non-surgical treatment typically involves immobilization with a sling or shoulder immobilizer, application of ice packs, and taking medications for pain. Surgery for clavicle fractures may be necessary if a bone fragment has broken through the skin or if the bone is severely out of place. Surgery to correct a clavicle fracture may involve securing the fracture with plates and screws or by placing rods inside the bone. Surgery for a displaced fracture of the upper arm bone usually involves fixation of the fracture fragments with plates, screws, or pins. Only rarely is surgery necessary in the case of a fractured scapula.

Shoulder Injuries-Overuse to Trauma: Part 1

The National Ambulatory Medical Care Survey found that over the course of a year up to 50% of the general population will experience shoulder pain, with half of them consulting a physician. In most cases, this discomfort is related to trauma, although there are many other causes for shoulder pain.

The shoulder is made up of three bones: the upper arm bone (humerus), the shoulder blade (scapula), and the collarbone (clavicle). The head of the humerus fits into a curved socket, called the glenoid, which is part of the shoulder blade. A group of muscles and tendons, known collectively as the rotator cuff, keep the arm bone centered in the shoulder socket and allow for movement in many different directions. This mobility, however, comes at a price, since the shoulder joint is less stable than most joints in the body. This increases its susceptibility to a number of problems.

Overuse Conditions Affecting the Shoulder. Overuse conditions, also known repetitive strain injury (RSI), are conditions characterized by chronic inflammation brought on by excessive use of a particular body part. Overuse conditions in adults are most often occupationally-related, whereas in younger individuals they are often a result of a sports-related repetitive activity. Some of the most common overuse conditions affecting the shoulder are:

• Bursitis--- A bursa is a fluid-filled sac that acts as a cushion between muscles, tendons, and joints. There are a number of bursae around the shoulder joint. The one most commonly affected in the shoulder is located between the rotator cuff and a portion of the shoulder blade known as the acromion. Excessive use of the shoulder, such as repeated raising and lowering of the arm, can cause this bursa to become inflamed, a condition known as subacromial bursitis. Subacromial bursitis can have an impact on many activities of daily living as well as affecting job performance with certain occupations.
   
• Tendinitis---A tendon is specialized type of connective tissue that connects muscles to bone. Tendonitis, or inflammation of the tendon, can develop suddenly from overuse (acute tendonitis) or more gradually, due to aging and “wear and tear” (chronic tendonitis). Examples of activities that can cause shoulder tendonitis include playing sports that require the arm to be moved over the head repeatedly, as in tennis, and working with the arm overhead for prolonged periods, as when painting. The most commonly affected tendons in the shoulder are the rotator cuff tendons and the tendon that connects to the biceps muscle.
   
• Impingement---This common shoulder condition is named for its mechanical cause, rather than for an affected structure. In shoulder impingement, a portion of the shoulder blade known as the acromion rubs against the underlying soft tissues (bursa, tendons, muscles) when the arm if lifted overhead. This repeated rubbing or “impingement” causes these tissues to become inflamed with the development of bursitis or tendonitis. Symptoms of impingement are similar to that of shoulder bursitis/tendonitis and include shoulder pain with lifting, reaching behind the back, or with overhead movements. Commonly, impingement-related pain will be felt on the outside (lateral aspect) of the shoulder or become particularly noticeable at night.
    

Treatment of Overuse Conditions of the Shoulder: Almost always, initial treatment of overuse conditions of the shoulder is nonsurgical. Resolution of symptoms, however, may take several weeks or months with very gradual improvement and return to function. The first step is to modify activity so that painful motions, such as overhead lifting, are avoided. Typically, a course of non-steroidal anti-inflammatory medicines (ibuprofen, Aleve, others) are given to help reduce pain and swelling. Once the pain has begun to resolve, physical therapy, either self-directed or formal, is employed to help restore strength and regain any range of motion that had been lost. This program usually involves some combination of stretching, strengthening and range of motion exercises. In some instances, an injection of a corticosteroid into the region of the inflamed bursa or tendon may also be helpful if the measures mentioned above are not completely successful.

About ALS (Lou Gehrig's Disease)

ALS is an abbreviation for the disease, Amyotrophic Lateral Sclerosis. Also known as “Lou Gehrig’s Disease”, ALS is a progressive degenerative disease that affects the nerves that control voluntary movements and muscle power. The specific types of nerves affected are the “motor neurons”, located in the brain and spinal cord. These are the nerves that serve as a communication link between the brain and the muscles that they control. With degeneration and eventual death of the motor neurons, muscles weaken, waste away (atrophy), and ultimately cease working. At this time, there is no known cure for ALS with most people living only 3 to 5 years following its diagnosis.

What are the symptoms of ALS? The onset of ALS is typically very gradual with initial symptoms being so subtle that the diagnosis may be overlooked. Early symptoms include fine muscle twitches called fasiculations, muscle weakness affecting the hand, arm or leg, and slurred speech. Over time, the muscle weakness may become more profound with disturbance of normal walking gait, difficulty with performing fine motor activities, such as buttoning a shirt, or excessive fatigue of the arms or legs with minimal exertion. Eventually, the muscles that control the important functions of chewing, swallowing, and breathing are affected by the nerve degeneration.

What causes ALS? There is no known cause for ALS, although environmental and genetic factors have been suspected. Some of the environmental exposures suspected (but not confirmed) of causing ALS include heavy metals (e.g., lead and mercury), solvents, radiation, and agricultural chemicals. Military veterans who were deployed to the Gulf region during the 1991 war have been approximately twice as likely to develop ALS as compared to military personnel who were not in the region, although the reason for this has not been determined. About 5-10% of ALS cases occurs within families and is related to a genetic mutation. This is called “familial ALS” and can be passed down through generations. Genetic testing is sometimes done to look for the possibility that ALS is related to a gene mutation, but in general, this is only done when someone has symptoms of ALS in addition to having a family history of ALS. A more thorough discussion of genetic testing for ALS and when it is most appropriately employed can be found on the ALS Association website. The great majority of ALS cases occur sporadically, with no family history of the disease. Most people who develop ALS are between the ages of 40 and 70, with an average age of 55 at the time of diagnosis.

How is ALS diagnosed? Typically, ALS is confirmed by a neurologist after reviewing the person’s symptoms and physical signs, and performing certain tests and procedures. Tests could include magnetic resonance imaging (MRI) of the brain, muscle biopsy, electrodiagnostic testing (nerve conduction velocity and electromyography), and spinal tap.

Is there a treatment for ALS? Motor neurons send signals to one another via chemical substances known as neurotransmitters. In ALS, an excess of one these neurotransmitters, an amino acid called glutamate, has been found to be present in the brain and spinal cord. Too much glutamate is thought to lead to excessive nerve stimulation and damage to the nerve cells. This knowledge has led to the development of riluzole, the only currently available medication used to treat the symptoms of ALS. Its major function appears to be a reduction in the release of glutamate by the nerve cell. Current research indicates that riluzole prolongs the life of persons with ALS by only a few months. Other than riluzole, treatment of ALS is directed primarily at its symptoms. This can include medications to help with muscle cramps or spasticity, physical therapy, nutritional support, and speech therapy. Antidepressants may be used for accompanying pain or depression. When the muscles controlling breathing are no longer able to function, mechanical support with a ventilator becomes necessary for survival.

ALS is a relatively uncommon disease in the U.S. with approximately 5,600 new cases being diagnosed each year. With up to 30,000 Americans living with the disease, however, it is one that many people have familiarity with through friends or family members. Hopefully, future research will shed additional light on its underlying cause as well as producing an effective treatment.