Osteoarthritis (Arthritis)

Osteoarthritis (OA) is the most common form of arthritis, especially among older people. 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 50s and 60s.

Signs and Symptoms

Signs and symptoms of OA may include the following:

Causes

OA is also often called degenerative joint disease because this condition involves the destruction of cartilage, which normally protects the joint. Although there are risk factors that may predispose a person to developing OA, it is usually not entirely clear what initiates the damage and loss of cartilage. Once the cartilage becomes somewhat damaged, however, it is more likely for further injury to ensue from repetitive use or another injury. Less commonly, OA is due to a fracture, mechanical abnormalities (such as unequal lower limb lengths), other bone and joint disease (such as gout), or an underlying metabolic or hormonal disorder.

Risk Factors

Risk factors for OA include:

Diagnosis

Because no single test can diagnose OA, most healthcare practitioners use a combination of the following methods to diagnose the disease and rule out the possibility of other causes of arthritis:

Preventive Care

The following measures may reduce the risk of developing OA:

Treatment Approach

The goals of OA treatment are to relieve symptoms, maintain mobility, and minimize disability. A combination of conventional treatment and complementary and alternative medicine (CAM) may be most effective.

It is possible, if not preferable, to treat OA without the use of medications. Pain-killers and anti-inflammatory medications should not be used as the primary treatment for OA—they should be used only in addition to other forms of treatment. 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 diminish the progression of the disease. Various surveys conducted in 1997 found that anywhere from 26% to 100% of patients with rheumatologic disorders (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 the following:

Lifestyle

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 following medications may be used in addition to lifestyle approaches (such as exercise) and alternative therapies (such as herbs and supplements) to treat OA:

Surgery and Other Procedures

Surgery is usually only considered as a last resort for OA. Surgical options include:

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 also recently gained popularity in the United States. Both compounds have been shown to inhibit inflammation in laboratory experiments. To evaluate the long-term effectiveness and possible toxic effects of these substances, the National Center for Complementary and Alternative Medicine (NCCAM) of the National Institutes of Health (NIH) has funded a large clinical trial comparing glucosamine, chondroitin, and a combination of the two agents, to placebo. The study is projected to be complete by March 2005.

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: 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 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. Participants in the glucosamine group reported no more adverse effects than those in the placebo group.

Some experts believe that another form of glucosamine known as glucosamine hydrochloride may be absorbed more readily by the body than glucosamine sulfate. 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 has been found to produce the following results in several well-designed clinical trials: Although glucosamine and chondroitin have been studied separately, accumulating evidence suggests that taking both supplements together may be a safe and effective treatment for OA. As mentioned earlier, a large NIH-funded study comparing glucosamine, chondroitin, and a combination of the two agents to placebo is currently underway. The study is expected to be completed by March 2005.

Medical experts caution that glucosamine and chondroitin supplements sold over the counter in the United States are not regulated by the U.S. Food and Drug Administration, meaning that 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, but researchers are not clear how this works. Clinical trials 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: In an extensive review of studies conducted with SAMe (collectively representing over 20,000 people), including trials of longer duration (namely, 2 years), the supplement was associated with the following benefits: Vitamin D
Vitamin D is essential to bone and cartilage health. Studies evaluating vitamin D use for OA have found the following: Antioxidants
Antioxidants appear to significantly ease oxidative stress and inflammation caused by free radicals and may therefore 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 to reduce the symptoms of OA: In addition, more extensive research on vitamin E 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: 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 all people with the condition. It does appear, however, that niacinamide must be used for at least 3 weeks before the benefits described are seen. 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 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, such as 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.

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: It is also important to note, however, 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, however, 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:

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: 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: Cat's claw (Uncaria tomentosa)
In astudy 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. For example, a group of 29 people awaiting surgery for OA of the knee demonstrated significant improvement in their ability to climb stairs and in their walking pace after receiving acupuncture compared to those who were not treated with acupuncture.

The National Institutes of Health 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: 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.

Massage and Physical Therapy

Physical Therapy
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: 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, magnets can be applied 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 mainly used poor methods that make 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: 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: 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. These mechanical aids are used 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: Other common homeopathic remedies for OA include: 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.

Ayurveda

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

Traditional Chinese Medicine

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: 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 3 months showed significant improvement compared to those in the control group in the following areas:

Other Considerations

Pregnancy
Most women who become pregnant are too young to have OA. 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 that are approved by their obstetrician.

Prognosis and Complications

Complications of OA include: 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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