Shoulder Problems

What is the shoulder?

The shoulder is made up of several layers, including:

• bones - the collarbone (clavicle), the shoulder blade (scapula), and the upper arm bone (humerus)

• the joints that facilitate movement include:
  • the clavicle
  • the acromioclavicular (AC) joint where the clavicle meets the acromion
  • the shoulder joint (glenohumeral joint) - a ball-and-socket joint that facilitates forward, circular, and backward movement of the shoulder
    
• ligaments - the soft tissue structures that connect bones to bones, including:
  • joint capsule - a group of ligaments that connect the humerus to the socket of the shoulder joint on the scapula to stabilize the shoulder and keep it from dislocating
  • ligaments that attach the clavicle to the acromion
  • ligaments that connect the clavicle to the scapula
    
• acromion - the roof (highest point) of the shoulder that is formed by a part of the scapula

• tendons - soft tissue structures that attach muscles to bone. The rotator cuff tendons are a group of tendons that connect the deepest layer of muscles to the humerus.

• muscles - to help support and rotate the shoulder in many directions

• bursa - a sac between two moving surfaces that has a small amount of lubricating fluid inside; located between the rotator cuff muscle layer and the outer layer of large bulky muscles

• rotator cuff - composed of tendons, the rotator cuff and associated muscles holds the ball of the glenohumeral joint at the top of the upper arm bone (humerus)

Shoulder pain may be localized in a specific area or may spread to areas around the shoulder or down the arm.

What are some of the different types of shoulder problems?

Common shoulder problems include:

Dislocation - The shoulder joint is the most frequently dislocated major joint of the body -- often caused by a significant force that separates the shoulder joint's ball (the top rounded portion of the upper arm bone, or humerus) away from the joint's socket (glenoid).

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Separation - The shoulder becomes separated when the ligaments attached to the collarbone (clavicle) are torn or partially torn away from the shoulder blade (scapula). Shoulder separation may be caused by a sudden, forceful blow to the shoulder or as a result of a fall.

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Bursitis often occurs when tendonitis and impingement syndrome cause inflammation of the bursa sacs that protect the shoulder.

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Impingement syndrome is caused by the squeezing of the rotator cuff.

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Tendonitis of the shoulder is caused when the rotator cuff and/or biceps tendon become inflamed, usually as a result of being pinched by surrounding structures. The injury may vary from mild inflammation to involvement of most of the rotator cuff. When the rotator cuff tendon becomes inflamed and thickened, it may get trapped under the acromion.

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Rotator cuff tear - one or more rotator cuff tendons become inflamed from overuse, aging, a fall on an outstretched hand, or a collision.

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Adhesive capsulitis (frozen shoulder) - a severely restrictive condition frequently caused by injury that leads to lack of use due to pain. Intermittent periods of use may cause inflammation and adhesions to grow between the joint surfaces thus restricting motion. There is also a lack of synovial fluid to lubricate the gap between the arm bone and socket that normally helps the shoulder joint to move. This restricted space between the capsule and ball of the humerus distinguishes adhesive capsulitis from the less complicated condition known as stiff shoulder.

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Fracture - a partial or total crack or break through a bone, usually caused by an impact injury.

What causes shoulder problems?

Although the shoulder is the most movable joint in the body, it is also an unstable joint because of its range of motion. Because the ball of the upper arm is larger than the socket of the shoulder, it is susceptible to injury. The shoulder joint must also be supported by soft tissues -- muscles, tendons, and ligaments, which are also subject to injury, overuse, and under use.

Degenerative conditions and other diseases in the body may also contribute to shoulder problems, or generate pain that travels along nerves to the shoulder.

How are shoulder problems diagnosed?

In addition to a complete medical history, diagnostic procedures may include:

• physical examination - to determine range of motion, location of pain, and level of joint instability/stability

• imaging procedures, such as:
  
  • x-rays
  • arthrogram - a test in which dye is injected into the shoulder joint and x-rays are taken to outline structures of the shoulder. When the fluid leaks into an area where it does not belong, disease or injury may be considered, as a leak would provide evidence of a tear, opening, or blockage.
  • computed tomography (CT or CAT scan) - a non-invasive procedure that takes cross-sectional images of the brain and other internal organs; to detect any abnormalities that may not show up on an ordinary x-ray.
  • magnetic resonance imaging (MRI) - a non-invasive procedure that produces two-dimensional views of an internal organ or structure, especially the brain or spinal cord.
  • electromyogram (EMG) - an electric test that may show the presence of nerve damage.
  • ultrasound - provides images of the soft tissues that support the shoulder without the use of radiation.

• laboratory tests - to determine if other problems may be the cause.

• arthroscopy - to look into the shoulder joint with an arthroscope, a small camera inserted into the shoulder joint to make a diagnosis, and possibly to treat the problem. The procedure usually requires general anesthesia and is performed in an operating room.

Treatment of shoulder problems:

Your physician(s) will determine specific treatment based on:

• your age, overall health, and medical history
• extent of the disease
• your tolerance for specific medications, procedures, or therapies
• expectations for the course of the disease
• your opinion or preference

Treatment may include:

• activity modification
• rest
• physical therapy
• medications
• surgery