Shoulder problems

From Academic Kids

Each year, shoulder problems account for about 1.5 million visits to orthopaedic surgeons--doctors who treat disorders of the bones, muscles, and related structures. According to the American Academy of Orthopaedic Surgeons, about four million people in the United States seek medical care each year for shoulder sprain, strain, dislocation, or other problems.

Contents

Shoulder structures and functions

The shoulder joint is composed of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone) (see diagram). Two joints facilitate shoulder movement. The acromioclavicular (AC) joint is located between the acromion (part of the scapula that forms the highest point of the shoulder) and the clavicle. The glenohumeral joint, to which the term "shoulder joint" commonly refers, is a ball-and-socket joint that allows the arm to rotate in a circular fashion or to hinge out and up away from the body. (The "ball" is the top, rounded portion of the upper arm bone or humerus; the "socket," or glenoid, is a dish-shaped part of the outer edge of the scapula into which the ball fits.) Arm movement is further facilitated by the ability of the scapula itself to slide along the rib cage. The capsule is a soft tissue envelope that encircles the glenohumeral joint. It is lined by a thin, smooth synovial membrane.

The bones of the shoulder are held in place by muscles, tendons, and ligaments. Tendons are tough cords of tissue that attach the shoulder muscles to bone and assist the muscles in moving the shoulder. Ligaments attach shoulder bones to each other, providing stability. For example, the front of the joint capsule is anchored by three glenohumeral ligaments.

The rotator cuff is a structure composed of tendons that, with associated muscles, holds the ball at the top of the humerus in the glenoid socket and provides mobility and strength to the shoulder joint.

Two filmy sac-like structures called bursae permit smooth gliding between bone, muscle, and tendon. They cushion and protect the rotator cuff from the bony arch of the acromion.

Origin and causes of shoulder problems

The shoulder is the most movable joint in the body. However, it is an unstable joint because of the range of motion allowed. It is easily subject to injury because the ball of the upper arm is larger than the shoulder socket that holds it. To remain stable, the shoulder must be anchored by its muscles, tendons, and ligaments. Some shoulder problems arise from the disruption of these soft tissues as a result of injury or from overuse or underuse of the shoulder. Other problems arise from a degenerative process in which tissues break down and no longer function well.

Shoulder pain may be localized or may be referred to areas around the shoulder or down the arm. Disease within the body (such as gallbladder, liver, or heart disease, or disease of the cervical spine of the neck) also may generate pain that travels along nerves to the shoulder.

How shoulder problems are diagnosed

Following are some of the ways doctors diagnose shoulder problems:

  • Medical history (the patient tells the doctor about an injury or other condition that might be causing the pain).
  • Physical examination to feel for injury and discover the limits of movement, location of pain, and extent of joint instability.
  • Tests to confirm the diagnosis of certain conditions. Some of these tests include:
    • x ray
    • arthrogram--Diagnostic record that can be seen on an x ray after injection of a contrast fluid into the shoulder joint to outline structures such as the rotator cuff. In disease or injury, this contrast fluid may either leak into an area where it does not belong, indicating a tear or opening, or be blocked from entering an area where there normally is an opening.
    • MRI (magnetic resonance imaging)--A non-invasive procedure in which a machine produces a series of cross-sectional images of the shoulder.
    • Other diagnostic tests, such as injection of an anesthetic into and around the shoulder joint, are discussed in specific sections of this booklet.

Dislocation

Description

The shoulder joint is the most frequently dislocated major joint of the body. In a typical case of a dislocated shoulder, a strong force that pulls the shoulder outward (abduction) or extreme rotation of the joint pops the ball of the humerus out of the shoulder socket. Dislocation commonly occurs when there is a backward pull on the arm that either catches the muscles unprepared to resist or overwhelms the muscles. When a shoulder dislocates frequently, the condition is referred to as shoulder instability. A partial dislocation where the upper arm bone is partially in and partially out of the socket is called a subluxation.

Signs and diagnosis

The shoulder can dislocate either forward, backward, or downward. Not only does the arm appear out of position when the shoulder dislocates, but the dislocation also produces pain. Muscle spasms may increase the intensity of pain. Swelling, numbness, weakness, and bruising are likely to develop. Problems seen with a dislocated shoulder are tearing of the ligaments or tendons reinforcing the joint capsule and, less commonly, nerve damage. Doctors usually diagnose a dislocation by a physical examination, and x rays may be taken to confirm the diagnosis and to rule out a related fracture.

Treatment

Doctors treat a dislocation by putting the ball of the humerus back into the joint socket--a procedure called a reduction. The arm is then immobilized in a sling or a device called a shoulder immobilizer for several weeks. Usually the doctor recommends resting the shoulder and applying ice three or four times a day. After pain and swelling have been controlled, the patient enters a rehabilitation program that includes exercises to restore the range of motion of the shoulder and strengthen the muscles to prevent future dislocations. These exercises may progress from simple motion to the use of weights.

After treatment and recovery, a previously dislocated shoulder may remain more susceptible to reinjury, especially in young, active individuals. Ligaments may have been stretched or torn, and the shoulder may tend to dislocate again. A shoulder that dislocates severely or often, injuring surrounding tissues or nerves, usually requires surgical repair to tighten stretched ligaments or reattach torn ones.

Sometimes the doctor performs surgery through a tiny incision into which a small scope (arthroscope) is inserted to observe the inside of the joint. After this procedure, called arthroscopic surgery, the shoulder is generally immobilized for about 6 weeks and full recovery takes several months. Arthroscopic techniques involving the shoulder are relatively new and many surgeons prefer to repair a recurrent dislocating shoulder by the time-tested open surgery under direct vision. There are usually fewer repeat dislocations and improved movement following open surgery, but it may take a little longer to regain motion.

Separation

Description

A shoulder separation occurs where the collarbone (clavicle) meets the shoulder blade (scapula). When ligaments that hold the AC (acromioclavicular) joint together are partially or completely torn, the outer end of the clavicle may slip out of place, preventing it from properly meeting the scapula. Most often the injury is caused by a blow to the shoulder or by falling on an outstretched hand.

Signs and diagnosis

Shoulder pain or tenderness and, occasionally, a bump in the middle of the top of the shoulder (over the AC joint) are signs that a separation may have occurred. Sometimes the severity of a separation can be detected by taking x rays while the patient holds a light weight that pulls on the muscles, making a separation more pronounced.

Treatment

A shoulder separation is usually treated conservatively by rest and wearing a sling. Soon after injury, an ice bag may be applied to relieve pain and swelling. After a period of rest, a therapist helps the patient perform exercises that put the shoulder through its range of motion. Most shoulder separations heal within 2 or 3 months without further intervention. However, if ligaments are severely torn, surgical repair may be required to hold the clavicle in place. A doctor may wait to see if conservative treatment works before deciding whether surgery is required.

Tendinitis, bursitis, and impingement syndrome

Description

These conditions are closely related and may occur alone or in combination. If the rotator cuff and bursa are irritated, inflamed, and swollen, they may become squeezed between the head of the humerus and the acromion. Repeated motion involving the arms, or the aging process involving shoulder motion over many years, may also irritate and wear down the tendons, muscles, and surrounding structures.

Tendinitis is inflammation (redness, soreness, and swelling) of a tendon. In tendinitis of the shoulder, 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. Squeezing of the rotator cuff is called impingement syndrome.

Tendinitis and impingement syndrome are often accompanied by inflammation of the bursa sacs that protect the shoulder. An inflamed bursa is called bursitis. Inflammation caused by a disease such as rheumatoid arthritis may cause rotator cuff tendinitis and bursitis. Sports involving overuse of the shoulder and occupations requiring frequent overhead reaching are other potential causes of irritation to the rotator cuff or bursa and may lead to inflammation and impingement.

Signs

Signs of these conditions include the slow onset of discomfort and pain in the upper shoulder or upper third of the arm and/or difficulty sleeping on the shoulder. Tendinitis and bursitis also cause pain when the arm is lifted away from the body or overhead. If tendinitis involves the biceps tendon (the tendon located in front of the shoulder that helps bend the elbow and turn the forearm), pain will occur in the front or side of the shoulder and may travel down to the elbow and forearm. Pain may also occur when the arm is forcefully pushed upward overhead.

Diagnosis

Diagnosis of tendinitis and bursitis begins with a medical history and physical examination. X rays do not show tendons or the bursae but may be helpful in ruling out bony abnormalities or arthritis. The doctor may remove and test fluid from the inflamed area to rule out infection. Impingement syndrome may be confirmed when injection of a small amount of anesthetic (lidocaine hydrochloride) into the space under the acromion relieves pain.

Treatment

The first step in treating these conditions is to reduce pain and inflammation with rest, ice, and anti-inflammatory medicines such as aspirin, naproxen (Naprosyn*), ibuprofen (Advil, Motrin, or Nuprin), or COX-2 selective inhibitors (Celebrex, Vioxx, or Nobic). In some cases the doctor or therapist will use ultrasound (gentle sound-wave vibrations) to warm deep tissues and improve blood flow. Gentle stretching and strengthening exercises are added gradually. These may be preceded or followed by use of an ice pack. If there is no improvement, the doctor may inject a corticosteroid medicine into the space under the acromion. While steroid injections are a common treatment, they must be used with caution because they may lead to tendon rupture. If there is still no improvement after 6 to 12 months, the doctor may perform either arthroscopic or open surgery to repair damage and relieve pressure on the tendons and bursae.

  • Brand names included in this booklet are provided as examples only, and their inclusion does not mean that these products are endorsed by the National Institutes of Health or any other Government agency. Also, if a particular brand name is not mentioned, this does not mean or imply that the product is unsatisfactory.

Rotator cuff tear

Note: See Rotator cuff tear for more details.

The term "rotator cuff" refers to a group of four tendons that blend together as they attach to the upper end of the arm bone (humerus). Normally these tendons transmit the force of muscles orignating on the shoulder blade (scapula) to the arm providing motion and stability. The most commonly affected tendon is that of the supraspinatus muscle. Defects in the rotator cuff can come from an injury (cuff tear) or from degeneration (cuff wear). The degree to which a tendon is reparable depends on its quantity and quality. Degenerated tendons are often frail and retracted and may not me amenable to repair. Individuals that are elderly, smokers, or those having had cortisone injections often have weaker tendon tissue that fails without a significant injury. By contrast those whose tendon was torn by a substantial fall often have good quality tendon that can be repaired if surgery is performed promptly after the injury. The symtoms of rotator cuff disease include difficulty lifting the arm. Repair of a rotator cuff requires that the tendon be securely anchored to the bone at surgery and that the repari be protected for several months during healing. Further information that should be considered in the treatment of rotator cuff tears can be found at <http://www.orthop.washington.edu/uw/rotatorcuff/tabID__3376/ItemID__187/PageID__360/Articles/Default.aspx>

Frozen shoulder (adhesive capsulitis)

Note: See Frozen shoulder for detailed article

As the name implies, movement of the shoulder is severely restricted in people with a "frozen shoulder." This condition, which doctors call adhesive capsulitis, is frequently caused by injury that leads to lack of use due to pain. Rheumatic disease progression and recent shoulder surgery can also cause frozen shoulder. Intermittent periods of use may cause inflammation. Adhesions (abnormal bands of tissue) grow between the joint surfaces, restricting motion. There is also a lack of synovial fluid, which normally lubricates the gap between the arm bone and socket to help the shoulder joint move. It is this restricted space between the capsule and ball of the humerus that distinguishes adhesive capsulitis from a less complicated painful, stiff shoulder. People with diabetes, stroke, lung disease, rheumatoid arthritis, and heart disease, or who have been in an accident, are at a higher risk for frozen shoulder. The condition rarely appears in people under 40 years old.

Fracture

Description

A fracture involves a partial or total crack through a bone. The break in a bone usually occurs as a result of an impact injury, such as a fall or blow to the shoulder. A fracture usually involves the clavicle or the neck (area below the ball) of the humerus.

Signs and diagnosis

A shoulder fracture that occurs after a major injury is usually accompanied by severe pain. Within a short time, there may be redness and bruising around the area. Sometimes a fracture is obvious because the bones appear out of position. Both diagnosis and severity can be confirmed by x rays.

Treatment

When a fracture occurs, the doctor tries to bring the bones into a position that will promote healing and restore arm movement. If the clavicle is fractured, the patient must at first wear a strap and sling around the chest to keep the clavicle in place. After removing the strap and sling, the doctor will prescribe exercises to strengthen the shoulder and restore movement. Surgery is occasionally needed for certain clavicle fractures.

Fracture of the neck of the humerus is usually treated with a sling or shoulder immobilizer. If the bones are out of position, surgery may be necessary to reset them. Exercises are also part of restoring shoulder strength and motion.

Arthritis of the shoulder (glenohumeral joint)

Description

In arthritis of the shoulder, the cartilage of the ball and socket (glenohumeral joint) is lost so that bone rubs on bone. It may be caused by wear and tear (degenerative joint disease), injury (traumatic arthritis), surgery (secondary degenerative joint disease), inflammation (rheumatoid arthritis) or infection (septic arthritis).

Signs and diagnosis

Arthritis of the shoulder causes pain and loss of motion and use of the shoulder.

Xrays of the shoulder show loss of the normal space between the ball and socket.


Treatment

Early on arthritis of the shoulder can be managed with mild analgesics and gentle exercises <http://www.orthop.washington.edu/uw/roughshoulder/tabID__3376/ItemID__223/PageID__453/Articles/Default.aspx>. In the case of rheumatoid arthritis, specific medications selected by a rheumatologist may offer substantial relief.

When exercises and medications are no longer effective, shoulder replacement surgery for arthritis may be considered. In this operation, a surgeon replaces the shoulder joint with an artificial ball for the top of the humerus and a cap (glenoid) for the scapula. Passive shoulder exercises (where someone else moves the arm to rotate the shoulder joint) are started soon after surgery. Patients begin exercising on their own about 3 to 6 weeks after surgery. Eventually, stretching and strengthening exercises become a major part of the rehabilitation program. The success of the operation often depends on the condition of rotator cuff muscles prior to surgery and the degree to which the patient follows the exercise program.

In young and active patients a partial shoulder replacement with a non-prosthetic glenod arthroplasty may also be a consideration.

Temporary, emergency treatment

A mnemonic for the basic treatment principles of any musculoskeletal problems is PRICE: Protection, Rest, Ice, Compression, and Elevation:

  • Protection: Guard the shoulder to prevent further injury.
  • Rest: Reduce or stop using the injured area for 48 hours.
  • Ice: Put an ice pack on the injured area for 20 minutes at a time, 4 to 8 times per day. Use a cold pack, ice bag, or a plastic bag filled with crushed ice that has been wrapped in a towel.
  • Compression: Compress the area with bandages, such as an elastic wrap, to help stabilize the shoulder.
  • Elevation: Keep the injured area elevated above the level of the heart. Use a pillow to help elevate the injury.

If pain and stiffness persist, see a doctor.


This article contains text from the public domain document "Questions and Answers about Shoulder Problems", NIH Publication No. 01-4865, available from URL http://www.niams.nih.gov/hi/topics/shoulderprobs/shoulderqa.htm

Navigation

Academic Kids Menu

  • Art and Cultures
    • Art (http://www.academickids.com/encyclopedia/index.php/Art)
    • Architecture (http://www.academickids.com/encyclopedia/index.php/Architecture)
    • Cultures (http://www.academickids.com/encyclopedia/index.php/Cultures)
    • Music (http://www.academickids.com/encyclopedia/index.php/Music)
    • Musical Instruments (http://academickids.com/encyclopedia/index.php/List_of_musical_instruments)
  • Biographies (http://www.academickids.com/encyclopedia/index.php/Biographies)
  • Clipart (http://www.academickids.com/encyclopedia/index.php/Clipart)
  • Geography (http://www.academickids.com/encyclopedia/index.php/Geography)
    • Countries of the World (http://www.academickids.com/encyclopedia/index.php/Countries)
    • Maps (http://www.academickids.com/encyclopedia/index.php/Maps)
    • Flags (http://www.academickids.com/encyclopedia/index.php/Flags)
    • Continents (http://www.academickids.com/encyclopedia/index.php/Continents)
  • History (http://www.academickids.com/encyclopedia/index.php/History)
    • Ancient Civilizations (http://www.academickids.com/encyclopedia/index.php/Ancient_Civilizations)
    • Industrial Revolution (http://www.academickids.com/encyclopedia/index.php/Industrial_Revolution)
    • Middle Ages (http://www.academickids.com/encyclopedia/index.php/Middle_Ages)
    • Prehistory (http://www.academickids.com/encyclopedia/index.php/Prehistory)
    • Renaissance (http://www.academickids.com/encyclopedia/index.php/Renaissance)
    • Timelines (http://www.academickids.com/encyclopedia/index.php/Timelines)
    • United States (http://www.academickids.com/encyclopedia/index.php/United_States)
    • Wars (http://www.academickids.com/encyclopedia/index.php/Wars)
    • World History (http://www.academickids.com/encyclopedia/index.php/History_of_the_world)
  • Human Body (http://www.academickids.com/encyclopedia/index.php/Human_Body)
  • Mathematics (http://www.academickids.com/encyclopedia/index.php/Mathematics)
  • Reference (http://www.academickids.com/encyclopedia/index.php/Reference)
  • Science (http://www.academickids.com/encyclopedia/index.php/Science)
    • Animals (http://www.academickids.com/encyclopedia/index.php/Animals)
    • Aviation (http://www.academickids.com/encyclopedia/index.php/Aviation)
    • Dinosaurs (http://www.academickids.com/encyclopedia/index.php/Dinosaurs)
    • Earth (http://www.academickids.com/encyclopedia/index.php/Earth)
    • Inventions (http://www.academickids.com/encyclopedia/index.php/Inventions)
    • Physical Science (http://www.academickids.com/encyclopedia/index.php/Physical_Science)
    • Plants (http://www.academickids.com/encyclopedia/index.php/Plants)
    • Scientists (http://www.academickids.com/encyclopedia/index.php/Scientists)
  • Social Studies (http://www.academickids.com/encyclopedia/index.php/Social_Studies)
    • Anthropology (http://www.academickids.com/encyclopedia/index.php/Anthropology)
    • Economics (http://www.academickids.com/encyclopedia/index.php/Economics)
    • Government (http://www.academickids.com/encyclopedia/index.php/Government)
    • Religion (http://www.academickids.com/encyclopedia/index.php/Religion)
    • Holidays (http://www.academickids.com/encyclopedia/index.php/Holidays)
  • Space and Astronomy
    • Solar System (http://www.academickids.com/encyclopedia/index.php/Solar_System)
    • Planets (http://www.academickids.com/encyclopedia/index.php/Planets)
  • Sports (http://www.academickids.com/encyclopedia/index.php/Sports)
  • Timelines (http://www.academickids.com/encyclopedia/index.php/Timelines)
  • Weather (http://www.academickids.com/encyclopedia/index.php/Weather)
  • US States (http://www.academickids.com/encyclopedia/index.php/US_States)

Information

  • Home Page (http://academickids.com/encyclopedia/index.php)
  • Contact Us (http://www.academickids.com/encyclopedia/index.php/Contactus)

  • Clip Art (http://classroomclipart.com)
Toolbox
Personal tools