Shoulder Pain and Problems

What is the shoulder?

The shoulder is made up of several layers, including the following:

• bones - the collarbone (clavicle), the shoulder blade (scapula), which includes the glenoid (socket), and the upper arm bone (humerus), which includes the humeral head (ball).
• joints - facilitate movement, including the following:
  • clavicle
  • acromioclavicular (AC) joint (where the clavicle meets the acromion)
  • shoulder joint (glenohumeral joint) - a ball-and-socket joint that facilitates forward, circular, and backward movement of the shoulder. The joint with the greatest mobility in the body.
• ligaments - a white, shiny, flexible band of fibrous tissue that binds joints together and connects various bones and cartilage, including the following:
  • 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 by attaching to the coracoid process
• acromion - the roof (highest point) of the shoulder that is formed by a part of the scapula.
• tendons - the tough cords of tissue that connect muscles to bones. 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 closed space 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 four small muscles and their tendons which come together forming a "cuff" around the humeral head. It functions as a stabilizer for the glenohumeral jint (ball and socket).

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 the following:

• dislocation
  Because the shoulder joing is the most mobile joint in the body, 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 (humeral head) away from the socket (glenoid).
  
  
• separation
  This occurs at the acromio clavicular joint, when the ligaments attached to the collarbone (clavicle) are torn, or partially torn, away from the acromion (also part of the shoulder blade (scapula). Shoulder separation may be caused by a sudden, forceful blow to the shoulder, or as a result of a fall.
  
  
• bursitis
  An inflammatory process which often occurs when tendonitis and impingement syndrome cause inflammation of the bursa sacs that protect the shoulder.
  
  
• impingement syndrome
  Also an inflammatory process, caused by the excessive squeezing or rubbing of acromion and the rotator cuff. The pain associated with the syndrome is a result of an inflamed bursa (lubricating sac) over the rotator cuff, and/or inflammation of the rotator cuff tendons, and/or calcium deposits (much less common) in tendons due to wear and tear. Shoulder impingement syndrome can lead to a torn rotator cuff over a long period of time with frequent use (or abuse).
  
  
• tendonitis
  Tendonitis of the shoulder is caused when the rotator cuff and/or biceps tendon become inflamed, often as a result of being pinched by surrounding structures or from overuse. 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 become trapped under the acromion, causing impingement.
  
  
• rotator cuff tear
  A rotator cuff tear involves one or more rotator cuff tendons becoming inflamed from overuse, aging, a fall on an outstretched hand, or a collision. a tear may be either a full thickness (complete tear) or a partial thickness (not through and through), often a part of the impingement process.
  
  
• adhesive capsulitis (frozen shoulder)
  Frozen shoulder is a severely restrictive syndrome frequently caused by a minor 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. This restricted space between the capsule and ball of the humerus distinguishes adhesive capsulitis from the less complicated condition known as stiff shoulder. Frozen shoulder is often associated with neck or neurologic problems causing radiating pain in the shoulder and arm with subsequent disuse. This occurs three to four time more often in those diagnosed with diabetes than the normal population.
  
  
• fracture
  A fracture is a partial or total crack or break through a bone that usually occurs due to a impact injury.

What causes shoulder problems?

Although the shoulder is the most mobile joint in the body, it is also an unstable joint because of its amazing range-of-motion. 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, especially the cervical spine (neck), may also contribute to shoulder problems, or generate pain that travels along nerves to the shoulder, leading to pain and/or decreased use.

How are shoulder problems diagnosed?

In addition to a complete medical history and physical examination (to determine range-of-motion, location of pain, and level of joint instability/stability), diagnostic procedures for shoulder problems may include the following:

• x-ray - a diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.
  
• 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 that it does not belong, disease or injury may be considered, as a leak would provide evidence of a tear, opening, or blockage. This procdure is rarely needed with the advent of the MRI.
  
• magnetic resonance imaging (MRI) - a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body; can often determine damage or disease in a surrounding ligament or muscle.
• electromyogram (EMG) - a test to evaluate nerve and muscle function.
  
• ultrasound - a diagnostic technique which uses high-frequency sound waves to create an image of the internal organs.
• laboratory tests (to determine if other problems may be the cause)
  
• arthroscopy - a minimally-invasive diagnostic and treatment procedure used for conditions of a joint. This procedure uses a small, lighted, optic tube (arthroscope) which is inserted into the joint through a small incision in the joint. Images of the inside of the joint are projected onto a screen; used to evaluate the joint.

Treatment of shoulder problems:

Specific treatment of shoulder problems will be determined by your physician based on:

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

Treatment may include:

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

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