Osteoarthritis (OA), which is also known as osteoarthrosis or degenerative joint disease (DJD), is a progressive disorder of the joints caused by gradual loss of cartilage and resulting in the development of bony spurs and cysts at the margins of the joints. The name osteoarthritis comes from three Greek words meaning bone, joint, and inflammation.
OA is one of the most common causes of disability due to limitations of joint movement, particularly in people over 50. It is estimated that 2% of the United States population under the age of 45 suffers from osteoarthritis; this figure rises to 30% of persons between 45 and 64, and 63–85% in those over 65. About 90% of the American population will have some features of OA in their weight-bearing joints by age 40. Men tend to develop OA at earlier ages than women.
OA typically develops gradually over a period of years. Patients with OA may have joint pain on only one side of the body. It primarily affects the knees, hands, hips, feet, and spine.
Causes & symptoms
Osteoarthritis results from deterioration or loss of the cartilage that acts as a protective cushion between bones, particularly in weight-bearing joints such as the knees and hips. As the cartilage is worn away, the bone rubbing against bone forms spurs, areas of abnormal hardening, and fluid-filled pockets in the marrow known as subchondral cysts. As the disorder progresses, pain results from deformation of the bones and fluid accumulation in the joints. The pain is relieved by rest and made worse by moving the joint or placing weight on it. In early OA, the pain is minor and may take the form of mild stiffness in the morning. In the later stages of OA, chronic inflammation develops. The patient may experience pain even when the joint is not being used; and he or she may suffer permanent loss of the normal range of motion in that joint.
Until the late 1980s, OA was regarded as an inevitable part of aging, caused by simple "wear and tear" on the joints. This view has been replaced by recent research into cartilage formation. OA is now considered to be the end result of several different factors contributing to cartilage damage, and is classified as either primary or secondary.
Primary OA results from abnormal stresses on weight-bearing joints or normal stresses operating on weakened joints. Primary OA most frequently affects the finger joints, the hips and knees, the cervical and lumbar spine, and the big toe. The enlargements of the finger joints that occur in OA are referred to as Heberden's and Bouchard's nodes. Some gene mutations appear to be associated with OA. Obesity also increases the pressure on the weight-bearing joints of the body. Finally, as the body ages, there is a reduction in the ability of cartilage to repair itself. In addition to these factors, some researchers have theorized that primary OA may be triggered by enzyme disturbances, bone disease, or liver dysfunction.
Secondary OA results from chronic or sudden injury to a joint. It can occur in any joint. Secondary OA is associated with the following factors:
- trauma, including sports injuries
- repetitive stress injuries associated with certain occupations (like the performing arts, construction or assembly line work, computer keyboard operation, etc.)
- repeated episodes of gout or septic arthritis
- poor posture or bone alignment caused by developmental abnormalities
- metabolic disorders
History and physical examination
The two most important diagnostic clues in the patient's history are the pattern of joint involvement and the presence or absence of fever, rash, or other symptoms outside the joints. As part of the physical examination, the doctor will touch and move the patient's joint to evaluate swelling, limitations on the range of motion, pain on movement, and crepitus (a cracking or grinding sound heard during joint movement).
There is no laboratory test that is specific for osteoarthritis. Treatment is usually based on the results of diagnostic imaging. In patients with OA, x rays may indicate narrowed joint spaces, abnormal density of the bone, and the presence of subchondral cysts or bone spurs. The patient's symptoms, however, do not always correlate with x-ray findings. Magnetic resonance imaging (MRI) and computed tomography scans (CTscans) can be used to determine more precisely the location and extent of cartilage damage.
Food intolerance can be a contributing factor in OA, although this is more significant in rheumatoid arthritis. Dietary suggestions that may be helpful for people with OA include emphasizing high-fiber, complex-carbohydrate foods, while minimizing fats. Plants in the Solanaceae family, such as tomatoes, peppers, eggplant, and potatoes, should be avoided, as should refined and processed foods. Citrus fruits should also be avoided, as they may promote swelling. Foods that are high in bioflavonoids (berries as well as red, orange, and purple fruits and vegetables) should be eaten often. Black cherry juice (2 glasses twice per day) has been found to be particularly effective for partial pain relief.
In the past several years, a combination of glucosamine and chondroitin sulfate has been proposed as a dietary supplement that helps the body maintain and repair cartilage. Studies conducted in Europe have shown the effectiveness of this treatment but effects may not be evident until a month after initiating this treatment. These substances are nontoxic and do not require prescriptions. Other supplements that may be helpful in the treatment of OA include the antioxidant vitamins and minerals (vitamins A, C, E, selenium, and zinc) and the B vitamins, especially vitamins B6 and B5.
Naturopathic treatment for OA includes hydrotherapy, diathermy (deep-heat therapy), nutritional supplements, and botanical preparations, including yucca, devil's claw (Harpagophytum procumbens), and hawthorn (Crataegus laevigata) berries.
Electromagnetic field therapy is believed to increase blood flow and oxygen exchange to enhance the body's natural healing processes. This treatment is not suggested for use over an open wound or in combination with transdermal drug delivery patches, or by those who are pregnant or have insulin pumps or pacemakers. Magnets may be worn within a shoe insole, anklet, bracelet, or back support.
Traditional Chinese medicine
Practitioners of Traditional Chinese medicine treat arthritis with suction cups, massage, moxibustion (warming an area of skin by burning a herbal wick a slight distance above the skin), the application of herbal poultices, and internal doses of Chinese herbal formulas.
Daily acupressure can also provide relief for stiff, achy joints. Massage of the achy joints with a blend of aromatic oils, especially rosemary and chamomile is beneficial. Periods of imagery are another suggested treatment—for 10-20 minutes twice daily—where the joint pain is pictured as transformed into a liquid that trickles from the body into the nearest body of water and eventually into the ocean waves.
Patients with OA are encouraged to exercise as a way of keeping joint cartilage lubricated. Exercises that increase balance, flexibility, and range of motion are recommended for OA patients. These may include walking, swimming and other water exercises, yoga and other stretching exercises, or isometric exercises. Physical therapy may also include massage, moist hot packs, or soaking in a hot tub.
Treatment of OA patients is tailored to the needs of each individual. Patients vary widely in the location of the joints involved, the rate of progression, the severity of symptoms, the degree of disability, and responses to specific forms of treatment. Most treatment programs include several forms of therapy.
Patient education and psychotherapy
Patient education is an important part of OA treatment because of the highly individual nature of the disorder and its potential impacts on the patient's life. Patients who are depressed because of changes in employment or recreation usually benefit from counseling. The patient's family should be involved in discussions of coping, household reorganization, and other aspects of the patient's disease and treatment regimen.
Patients with mild OA may be treated only with pain relievers such as acetaminophen (Tylenol) or propoxyphene (Darvon). Most patients with OA, however, are given nonsteroidal anti-inflammatory drugs, or NSAIDs. These include compounds such as ibuprofen (Motrin, Advil), ketoprofen (Orudis), and flurbiprofen (Ansaid). The NSAIDs have the advantage of relieving inflammation as well as pain. They also have potentially dangerous side effects, including stomach ulcers, sensitivity to sun exposure, kidney disturbances, and nervousness or depression.
Some OA patients are treated with corticosteroids injected directly into the joints to reduce inflammation and slow the development of Heberden's nodes. Injections should not be regarded as a first-choice treatment and should be given only two or three times a year. A series of hyaluronic acid injections into the affected joint may help to lubricate and protect cartilage.
Surgical treatment of osteoarthritis may include the replacement of a damaged joint with an artificial part or appliance; surgical fusion of spinal bones; scraping or removal of damaged bone from the joint; or the removal of a piece of bone in order to realign the bone.
Depending on the location of the affected joint, patients with OA may be advised to use neck braces or collars, crutches, canes, hip braces, knee supports, bed boards, or elevated chair and toilet seats. They are also advised to avoid unnecessary knee bending, stair climbing, or lifting of heavy objects.
Since 1997, several new methods of treatment for OA have been investigated. Although they are still being developed and tested, they appear to hold promise. They include:
- Disease-modifying drugs. These compounds may be useful in assisting the body to form new cartilage or improve its repair of existing cartilage.
- Gene therapy.
- Cartilage transplantation. This technique is presently used in Sweden.
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