Osteoarthritis (OA) is the most common form of arthritis. It is a joint disease caused by the breakdown of cartilage -- the firm, rubbery tissue that cushions bones at joints.

Healthy cartilage allows bones to glide over one another and cartilage absorbs energy from the shock of physical movement. In OA cartilage breaks down and wears away. As a result, the bones rub together causing pain, swelling, and stiffness.

OA may also limit the range of motion in affected joints. Most often, OA develops in the hands, knees, hips, and spine.

The disease affects men and women nearly equally. More than 20 million people in the United States have OA. Symptoms tend to appear when individuals are in their fifties and sixties.

Signs and symptoms of OA may include the following:

• Joint pain (often a deep, aching pain) that is worsened by movement and improved with rest (in severe cases, a person may experience constant pain)
• Stiffness in the morning or after being inactive for more than 15 minutes
• Joint swelling
• Joints that are warm to the touch
• Crunching or crackling noise when the joint moves (crepitation)
• Limited range of motion
• Muscle weakness
• Abnormal growth of bony knobs near joints which cause deformities (such as Heberden's nodes, in which bumps appear on the outermost finger joints)

Most of the time, the cause of OA is unknown. It is primarily a disease due to aging. However, metabolic, genetic, chemical, and mechanical factors can play a role in its development.

Risk factors for OA include:

• Increasing age
• Genetic predisposition
• Obesity
• Injury to the joint
• History of inflammatory joint disease
• Metabolic or hormonal disorders (such as hemochromatosis and acromegaly)
• Bone and joint disorders present at birth
• Repetitive stressful joint use (such as with certain occupations like baseball, ballet dancing and construction work)
• Deposits of crystals in joints

There is no single test to diagnose OA, so most doctors use a combination of methods to diagnose the disease and rule out the possibility other causes. A physical exam can show limited range of motion, grating of a joint with motion, joint swelling, and tenderness. An x-ray of affected joints will show loss of the joint space and, in advanced cases, wearing down of the ends of the bone and bone spurs.

The following measures may reduce the risk of developing OA:

• Protecting an injured joint from further damage
• Exercising
• Losing weight
• Avoiding excessive repetitive motions

The goals of treatment are to relieve pain, maintain or improve joint mobility, increase the strength of the joints, and minimize the disabling affects of the disease. The specific treatment depends upon the affected joints.  A combination of conventional treatment and complementary and alternative medicine (CAM) may be most effective. Lifestyle approaches, including exercise, and many alternative medical therapies are becoming more popular and are considered safe and effective for the treatment OA.

Several natural remedies are at least as effective as conventional medication for symptom relief, and may help keep the disease from getting worse.  Americans spend more on natural remedies for OA than for any other medical condition. In 1997, researchers conducted various surveys and found that anywhere from 26 -100% of patients with painful conditions of the muscles, tendons, joints, and bones had tried some form of complementary and alternative medicine.

Some of the most promising complementary approaches for treating OA include:

• Reducing physical stress on the joint (lose weight and improve posture)
• Lifestyle changes (particularly exercise)
• Supplements including S-adenosylmethionine (SAMe), glucosamine and/or chondroitin, and antioxidants
• Herbs with anti-inflammatory properties, including devil's claw, willow bark, and capsaicin (cream)
• Acupuncture
• Chiropractic
• Physical therapy and magnet therapy 
• Yoga
• Tai chi

Exercise

Exercise to strengthen, stretch, and relax muscles around affected joints is almost always included in a treatment plan for OA. Several studies support the value of exercise for people with OA. One recent study, for example, found that people with OA of the knee who participated in a home exercise program experienced a 23% reduction in pain compared with only 6% reduction in people who did not exercise. Other studies also suggest that in addition to reduction of pain and disability, exercise improves strength, range of motion, balance and coordination, endurance, and posture.

Medications

The most common type of medication used to treat osteoarthritis are nonsteroidal, anti-inflammatory drugs (NSAIDs). They are common pain relievers that reduce pain and swelling. Types include aspirin, ibuprofen (Motrin, Advil, Nuprin), and naproxen (Aleve, Naprosyn, Naprelan, Anaprox). Although NSAIDs work well, long-term use can cause stomach problems, such as ulcers and bleeding. In April 2005, the FDA asked drug manufacturers of NSAIDs to include a warning label on their product that alerts users of an increased risk for cardiovascular events and gastrointestinal bleeding.

Other medications used to treat OA include:

• COX-2 inhibitors (coxibs). Coxibs block an inflammation-promoting enzyme called COX-2. This class of drugs was initially believed to work as well as traditional NSAIDs, but with fewer stomach problems. However, numerous reports of heart attacks and stroke have prompted the FDA to re-evaluate the risks and benefits of the COX-2s. Rofecoxib (Vioxx) and valdecoxib (Bextra) have been withdrawn from the U.S. market following reports of heart attacks in some patients taking the drugs. Celecoxib (Celebrex) was still available at the time of this report, but labeled with strong warnings and a recommendation that it be prescribed at the lowest possible dose for the shortest duration possible. Patients should ask their doctor whether the drug is appropriate and safe for them.
• Steroids. These medications are injected directly into the joint. They may also be used to reduce inflammation and pain.
• Artificial joint fluid (Synvisc, Hyalgan). These medications can be injected into the knee. They may temporary relief pain for up to 6 months.

Surgery and Other Procedures

Surgery to replace or repair damaged joints may be needed in severe, debilitating cases. Surgical options include:

• Arthroplasty (total or partial replacement of the deteriorated joint with an artificial joint)
• Arthroscopic surgery to trim torn and damaged cartilage and wash out the joint
• Osteotomy (change in the alignment of a bone to relieve stress on the bone or joint)
• Arthrodesis (surgical fusion of bones, usually in the spine)

Nutrition and Dietary Supplements

Glucosamine and Chondroitin

Glucosamine and chondroitin are compounds that occur naturally in human cartilage. For use in supplements, they are derived from bovine and calf cartilage. They have been widely used in Europe for more than a decade and have gained popularity in the United States. Both compounds have been shown to inhibit inflammation in laboratory experiments. There is some evidence that these supplements are helpful in controlling pain, although they do not appear to grow new cartilage.

Several reviews of clinical trials examining either glucosamine or chondroitin for OA concluded that these agents showed a number of benefits.

Glucosamine is administered orally or by injection into a joint or muscle. In its most commonly used form, glucosamine sulfate, it has been shown to:

• Decrease pain more effectively than placebo or NSAIDs (particularly ibuprofen)
• Take longer to begin working than ibuprofen but alleviate pain for a longer period of time
• Have significantly fewer adverse effects than ibufrofen
• Significantly improve pain and range of motion compared to both placebo and the NSAID piroxicam
• Have longer-lasting improvement of symptoms compared to piroxicam

Although encouraging, these studies did not examine the long-term safety and effectiveness of this supplement. In one long-term study in which 212 patients with OA received either glucosamine sulfate or placebo, or “dummy pill,” for 3 years, those in the glucosamine group experienced a 25% improvement in symptoms as well as diminished narrowing of the joint space, suggesting that the supplement slowed the progression of the disease. However, participants in the glucosamine group reported no more adverse effects than those in the placebo group.

Research shows that the body absorbs a form of glucosamine called glucosamine hydrochloride more readily by the body than glucosamine sulfate. However, since most research to date has been conducted on glucosamine sulfate, this is the form generally recommended for OA.

Chondroitin is also administered orally or by injection into a joint or muscle. It produced the following results in several well-designed clinical trials:

• Reduce the need for NSAIDs and other pain relievers
• Alleviate pain (sometimes more effectively than conventional medications; this effect even lasts up to 3 months after chondroitin supplementation is discontinued)
• Increase mobility
• Decrease swelling
• Reduce amount of fluid in the joint
• Enhance walking pace
• Slow the progression of the disease

Although glucosamine and chondroitin have been studied separately, accumulating evidence suggests that taking both supplements together may be a safe and effective at alleviating symptoms of OA. However, neither compound appears to stop the progression of the disease or regenerate damaged cartilage.

Medical experts caution that the U.S. Food and Drug Administration does not regulate  glucosamine and chondroitin supplements sold over the counter in the United States, so there is no standardization nor any guarantee that a product contains what is listed on the label.

S-adenosylmethionine (SAMe)

Laboratory and animal studies suggest that SAMe may reduce pain and inflammation to a similar degree as NSAIDs, but with fewer side effects. Researchers are still investigating how this works. Clinical studies with humans (although generally small in size and of short duration) have also shown favorable results for SAMe when used to relieve OA symptoms.

In several short-term studies (ranging from 4 to 12 weeks), SAMe supplements (1200 mg/day) compared favorably to NSAIDs in adults with knee, hip, or spine osteoarthritis in the following ways:

• Diminished morning stiffness
• Decreased pain
• Reduced swelling
• Improved range of motion
• Increased walking pace

In an extensive review of studies conducted with SAMe (collectively representing over 20,000 people), including trials of up to two years, the supplement was associated with the following benefits:

• Improved symptoms
• Fewer side effects
• No negative influences on cartilage production (unlike NSAIDs)
• Reduced risk for relapse

Vitamin D

Vitamin D is essential to bone and cartilage health. Studies evaluating vitamin D use for OA have found the following:

• Vitamin D prevents breakdown of cartilage
• Lower intake of vitamin D may be linked to greater risk of hip OA in older women and OA-related joint changes (visible on X-rays) in both men and women

Antioxidants

Antioxidants appear to significantly ease oxidative stress and inflammation caused by free radicals and may slow the progression of OA. Free radicals can be produced in the joints and have been implicated in many degenerative changes in the aging body, including destruction of cartilage and connective tissue. Antioxidants appear to offset the damage caused by free radicals. Although further evidence is needed to substantiate these claims, studies of groups of people observed over time suggest that the following antioxidants may help reduce the symptoms of OA:

• Vitamin A and beta-carotene
• Vitamin C
• Vitamin E

In addition, extensive research on vitamin E has revealed that people with OA experienced a significant reduction in pain after taking 600 mg of vitamin E per day, compared with those who received placebo. Those who took 600 mg of vitamin E three times a day experienced significantly less pain than those who took the NSAID diclofenac.

Niacinamide

In one preliminary study, 72 patients with OA were randomly assigned to receive niacinamide, a form of vitamin B3, or placebo. Participants in the niacinamide group experienced a 30% improvement in symptoms compared to a 10% worsening of symptoms experienced by those in the placebo group. People taking niacinamide reported the following:

• Improved joint mobility
• Reduced need for anti-inflammatory medications

The study authors speculate that niacinamide may aid cartilage repair and suggest that it may be used safely with NSAIDs to reduce inflammation. Further research is needed to fully understand how niacinamide benefits people with OA and to determine whether the results apply to everyone who has the condition. It does appear, however, that niacinamide must be used for at least 3 weeks before the patient will experience benefits. Experts also suggest that long-term use (1 to 3 years) may slow the progression of the disease.

Omega-3 Fatty Acids

Omega-3 fatty acids are found in coldwater fatty fish (such as salmon, mackerel, and herring), flaxseed, rapeseed, and walnuts. Research regarding the use of omega-3 fatty acid or fish oil supplements for inflammatory joint conditions has focused almost entirely on rheumatoid arthritis. Based on laboratory studies, however, many researchers suggest that diets rich in omega-3 fatty acids (and low in omega-6 fatty acids) may benefit people with other inflammatory disorders, including OA. In fact, several laboratory studies of cartilage-containing cells have found that omega-3 fatty acids decrease inflammation and reduce the activity of enzymes that break down cartilage. Patients also showed increased improvement when fish oil supplements were used in combination with olive oil.

Another potential source of omega-3 fatty acids is the New Zealand green lipped mussel (Perna canaliculus ), used for centuries by the Maori people for good health. In a trial involving 38 people with OA, nearly 40% of those who received P. canaliculus extracts experienced the following:

• Decreased joint stiffness and pain
• Increased grip strength
• Enhanced walking pace

However, it’s also important to note that 10% of participants experienced a temporary worsening of symptoms when first taking the supplement. In addition, it is better to use lipid extracts of P. canaliculus rather than powder as there is less chance of an allergic reaction. P. canaliculus should be avoided by people who are allergic to seafood.

Manganese

Manganese is among the substances that the body needs to build cartilage. In a clinical trial studying glucosamine, choindroitin, and manganese, 72 people with mild to moderate OA of the knee showed significant improvement in symptoms after taking these supplements in combination compared to those taking placebo. No serious side effects were reported. People with more severe forms of the disease did not show improvement as a result of taking the combination, however. Although earlier studies have indicated that low levels of manganese may contribute to degenerative joint conditions and bone loss, it is not clear from this trial what role manganese (as opposed to chondroitin and glucosamine) may have played in the results. Interestingly, an estimated 37% of Americans have low levels of manganese in their diets.

Other Supplements

According to anectodal reports and preliminary studies, other supplements that may potentially alleviate the symptoms of OA include:

• Bromelain (Ananas comosus) -- compared favorably to NSAIDs for pain reduction
• Boron -- population, animal, and preliminary human studies suggest that this trace element may reduce occurrence of symptoms of OA
• Collagen hydrolysate -- may stimulate cells to make collagen, although this theory is currently being tested

Herbs

Herbal remedies are among the most popular alternative therapies used by individuals with arthritis. Scientific evidence suggests that the following herbs are most effective for treating OA:

• Devil's claw (Harpagophytum procumbens)
• Willow bark (Salix spp.)
• Stinging nettle (Urtica dioica)
• A combination of aspen (Populus tremula), ash (Fraxinus excelsior), and goldenrod (Solidago viraurea)
• An Ayurvedic herbal mixture containing extracts of ashwagandha (Withania somnifera), boswellia (Boswellia serrata), and turmeric (Curcuma longa)
• A combination of willow bark (Salix spp.), black cohosh (Cimicifuga racemosa), sarsaparilla (Smilax spp.), guaiacum (Guaiacum officinale) resin, and poplar bark (Populus tremuloides )

Other herbs that have shown promise in the treatment of OA include:

Capsaicin (Capsicum frutescens)

Capsaicin is the main component in hot chili peppers (also known as cayenne). Applied to the surface of the skin, it is believed to deplete stores of a substance that contributes to inflammation and pain in arthritis. Several studies have shown that capsaicin cream provided much better pain relief than a placebo but no improvement in joint swelling, grip strength, or function for people with OA. Pain reduction generally begins 3 to 7 days after applying the capsaicin cream to the skin.

Avocado/Soybean extracts

Laboratory studies suggest that avocado/soybean extracts stimulate the growth of collagen (the principal protein of the skin, tendons, cartilage, and bone) in cartilage cells. In a study of 164 people with OA of the knee or hip, researchers found that participants who received avocado/soybean extracts for 6 months experienced the following improvements with few or no side effects:

• Reduction in pain and disability
• Increase in mobility
• Reduced need for NSAIDs

Cat's claw (Uncaria tomentosa )

In a study of 45 people with OA of the knee, those who received cat's claw reported a significant reduction in knee pain compared to those who received placebo.

Ginger (Zingiber officinale )

Ginger extract has long been used in traditional medical practices (such as Ayurvedic and Chinese) to decrease inflammation. Although there have been a few case reports of the benefit of ginger for OA in medical literature, one recent trial found that the herb was no more effective than ibuprofen or placebo in reducing symptoms of OA.

Kava kava (Piper methysticum )

Kava has traditionally been used as a pain reliever, but few scientific studies have evaluated kava for this purpose. In support of this traditional use, animal studies have also shown that kava reduces pain. Research in humans is warranted.

Acupuncture

Several controlled trials suggest that the ancient Chinese practice of acupuncture is an effective treatment for pain associated with OA, as well as for other aspects of the condition, including diminished joint function and reduced walking ability. In fact, a few studies have shown that people with OA experience better pain relief and improvement in function from acupuncture than from NSAIDs such as aspiroxicam. In a 6 month study of 570 participants funded by the National Institutes of Heath (NIH), researchers found that patients who received true acupuncture had a 40% increase in function, which is significantly better than those receiving the sham procedure. Another study of 300 people with OA found that after 8 weeks of treatment, pain and joint function improved more with acupuncture than with minimal acupuncture or no acupuncture in patients with OA of the knee.

The NIH is funding a large multicenter clinical trial due to be completed in 2001 to fully evaluate efficacy and safety of acupuncture for OA.

Chiropractic

Although there is no evidence that chiropractic care can reverse the joint degeneration that causes OA, some studies indicate that spinal manipulation may:

• Increase range of motion 
• Restore normal movement of the spine 
• Relax the muscles 
• Improve joint coordination 
• Reduce pain

In fact, a comprehensive review of the scientific literature suggests that chiropractic, especially when combined with glucosamine supplements and rehabilitative stretches and exercise, is an effective supplemental treatment for OA. Chiropractors will avoid using direct thrusts or pressure on red, swollen joints.

Physical Therapy

Physical therapy can be useful to improve muscle strength and the motion at stiff joints. Therapists have many techniques for treating OA.

Manual therapy and supervised exercise may decrease or delay the need for surgery in individuals with OA. In a trial evaluating physical therapy and exercise in people with OA of the knee, participants who received manual therapy to the lumbar spine, hip, ankle, and knees showed the following improvements:

• Less stiffness
• Reduced pain
• Improved functional ability
• Improved walking distance
• Less need for knee surgery 1 year later

If therapy does not make you feel better after 3 to 6 weeks, then it likely will not work at all.

Magnet Therapy

Exposure to electromagnetic fields has been shown to boost the number of cartilage-building cells and substances in laboratory experiments. One important study found that low-energy AC and DC magnetic fields stimulated the production of cartilage. For therapeutic purposes, users can apply magnets in one of two ways: directly to the skin surface over the bone or joint (capacitive coupling) or via pulsed electromagnetic fields (PEMFs) which induce an electrical current in the target tissue without making direct contact to the body (inductive coupling).

Studies using either type of magnet therapy for arthritis are limited, and the few that exist have used poor methods, making it difficult to draw any definite conclusions. However, in one study of 78 people with OA of the knee, magnet therapy (applied to the knee for 6 to 10 hours per day over a period of one month) significantly reduced pain as compared with placebo.

Balneotherapy (Hydrotherapy or spa therapy)

Balneotherapy is one of the oldest forms of therapy for pain relief for people with arthritis. The term "balneo" comes from the Latin word for bath (balneum) and refers to bathing in thermal or mineral waters. Sulfur-containing mud baths, for example, have been shown to relieve symptoms of arthritis. However, hydrotherapy, which can be performed under the guidance of certain physical therapists, is occasionally used interchangeably with the word balneotherapy. The goals of balneotherapy for arthritis include:

• Improving range of joint motion
• Increasing muscle strength
• Eliminating muscle spasm
• Enhancing functional mobility
• Easing pain

Although balneotherapy is most often used for psoriatic or rheumatoid arthritis, some medical experts believe that it may be beneficial for OA as well. However, one large review of many trials found little evidence to support its use.

Ice Massage, Transcutaneous Nerve Stimulation (TENS), and Electroacupuncture

In a well-designed trial comparing the effectiveness of TENS, electroacupuncture, and ice massage for the treatment of knee OA, each of these methods were found to:

• Reduce pain at rest
• Reduce stiffness
• Boost walking speed
• Increase quadriceps muscle strength
• Increase knee range of motion

TENS is a technique used by many physical therapists. When the nerve stimulation of TENS is applied to acupuncture points, it is called electroacupuncture.

Mechanical Aids

A variety of mechanical devices, called orthoses, are available for people with OA to help support and protect joints. Made from lightweight metal leather, elastic, foam, and plastic, orthoses allow some movement within the affected joint and do not restrict nearby joints. For example, splints or braces help align joints and properly distribute weight. Shock-absorbing soles in shoes can help in daily activities and during exercise. Physical therapists use these mechanical aids most frequently to treat arthritic hands, wrists, knees, ankles, and feet. Orthoses should be custom-fitted by a physical or occupational therapist.

Homeopathy

Although people with OA are best treated with an individualized homeopathic remedy chosen by a professional homeopath, several trials have found that some common homeopathic combinations may be at least as effective as conventional medications for OA. Potential remedies include:

• A topical homeopathic gel containing comfrey (Symphytum officinale), poison ivy (Rhus toxicodendron), and marsh-tea (Ledum palustre)
• A combination homeopathic preparation containing R. toxicodendron., Arnica montana (arnica), Solanum dulcamara (climbing nightshade), Sanguinarra canadensis (bloodroot), and Sulphur 
• A liquid homeopathic preparation containing R. toxicodendron, Causticum (potassium hydrate), and Lac vaccinum (cow's milk).

Other common homeopathic remedies for OA include:

• Calcarea carbonica (carbonate of lime or calcium carbonate)
• Bryonia (wild hops)
• Graphites
• Guaiacum

Mind/Body Medicine

Chronic pain and disability can make daily functioning difficult. A holistic approach to care in these clinical circumstances may positively affect both lifestyle and how one feels overall. Many people report that relaxation techniques, such as guided imagery and meditation, are an important part of comprehensive, holistic care, and help to alleviate pain and other symptoms of OA.

Yoga

This ancient Indian practice is well known for its physical, psychological, emotional, and spiritual benefits and is often recommended in the West to relieve musculoskeletal symptoms. In one clinical trial studying OA of the hand, the group practicing yoga showed significant decrease in pain and improved range of motion compared to those participating in non-yoga stretching and strengthening sessions. Certain yoga "asanas" (postures) strengthen the quadriceps and emphasize stretching, both of which benefit people with OA of the knee. People with arthritis should begin asanas slowly and they should be performed only after a warm up. Yoga is best performed under the careful guidance of a reputable instructor.

Herbal Remedies

Two recent trials comparing Ayurvedic herbal remedies with placebo found that participants who consumed the Ayurvedic herbs experienced significant improvement (with only mild side effects) compared to those in the placebo group. An Ayurvedic combination containing the following herbs significantly reduced pain and disability in people with OA:

• Winter cherry (Withania somnifera)
• Boswellia (Boswellia serrata)
• Turmeric (Curcuma longa )

Side effects of these herbs include nausea, dermatitis, and stomach pain.

Tai Chi

This ancient form of classical conditioning practiced in China for centuries has been shown to produce a number of benefits, including the following:

• Improved fitness
• Increased muscular strength
• Enhanced flexibility
• Reduced percentage of body fat
• Diminished risk of falls in the elderly

In a trial of subjects with OA of the knee or hip (ranging in age from 49 to 81), those who practiced tai chi twice a week for three months showed significant improvement compared to those in the control group in the following areas:

• Overall sense of quality of life
• Diminished feelings of stress/tension
• Increased satisfaction with general health
• Decreased fatigue
• Easier self management of arthritis symptoms

Pregnancy

Many of the herbs used in treatment for OA have not been tested on pregnant women and some are known to be unsafe for women who are pregnant. For this reason, pregnant women should only take substances for pain and other symptoms under the supervision of their obstetrician.

Prognosis and Complications

Complications of OA include:

• Inability to walk due to very advanced hip or knee OA
• Gastrointestinal bleeding and decreased kidney function resulting from long-term NSAID and aspirin use

Many people are able to control OA and prevent the condition from worsening over time. Joint deterioration in OA tends to be slower than that of rheumatoid arthritis, but knee OA is still the number one cause of disability in industrialized countries such as the United States. Increased fluid in joints and joint enlargement occur later in the course of the disease. In the most advanced stages, OA can cause full cartilage loss. In some cases joint replacement may become necessary. While OA can be a debilitating condition, current treatments have shown great promise in reducing pain and improving mobility.

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