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 SymptomsSigns 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 more 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 causing deformities (such as Heberden's nodes, in which bumps appear on the outermost finger joints)
CausesOA 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 FactorsRisk factors for OA include:
- Increasing age
- Genetic predisposition
- 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, such as happens with gout
DiagnosisBecause 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:
- Medical history—the doctor assesses symptoms by asking when they started and how they changed over time, including which joints are currently involved and have been affected previously. He or she will also ask about other medical conditions that may be contributing to current joint symptoms, and whether any factors (such as a fall or injury) could have caused these symptoms. The doctor will also determine whether the you are taking might interact with drugs that he or she is considering prescribing.
- Physical exam—each of the affected joints is examined for redness and swelling, crepitations (a crackling noise that may be heard and sensation felt when bone is rubbing on bone due to lack of cartilage), the presence of fluid in the joint, and the strength and range of motion of the joint.
- X-rays—can detect cartilage loss (which is indicated by narrowing of the joint space on x-ray) and bone damage such as bone spurs or erosions.
- Blood tests—are performed to look for general signs of inflammation, to help eliminate the possibility of other types of arthritis such as rheumatoid or Lyme's disease, and to check for possible markers of OA such as hyaluronic acid, a substance that normally provides lubrication for joints but breaks down in the case of OA.
- Joint aspiration – if fluid is present, it can be withdrawn from the joint for evaluation using a needle and syringe; normally with OA, there is not an adequate amount of fluid in the joint space to aspirate; therefore, evaluation of fluid may reveal another cause of arthritis such as gout or an infection.
Preventive CareThe following measures may reduce the risk of developing OA:
- Protecting an injured joint from further damage
- Losing weight
- Avoiding excessive repetitive motions
Treatment ApproachThe 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:
- Reducing physical stress on the joint (such as by losing weight or improving 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)
- Physical therapy and magnet therapy
- Tai chi
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.
MedicationsThe following medications may be used in addition to lifestyle approaches (such as exercise) and alternative therapies (such as herbs and supplements) to treat OA:
- Acetaminophen—reduces pain; the American Geriatrics Society recommends trying this medication first to alleviate pain.
- Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs)—reduce pain and swelling. These include numerous over-the-counter drugs, such as ibuprofen, ketoprofen, and naproxen sodium, as well as prescription medications, such as diclofenac, diflunisal, etodolac, fenoprofen, indomethacin, nabumetone, oxaprozin piroxicam, sulindac, salsalate, and tolmetin as well as stronger versions of the OTC drugs. Studies indicate that NSAIDs used for extended periods may cause stomach ulcers and other gastrointestinal problems. Some evidence even suggests that NSAIDs may accelerate the progression of OA because they appear to inhibit cartilage repair. Further studies are needed about this controversial issue.
- Cyclooxygenase 2 (COX-2) inhibitors (such as celecoxib and rofecoxib)—reduce pain and are less likely to cause the gastrointestinal side effects that sometimes accompany NSAIDs
- Tramadol—for pain that does not improve with other medications
- Hyaluronic acid—may restore lubrication to the joints. The medication is injected into affected joints once per week for 3 to 5 weeks and the effects may last up to one year. After each injection, weight-bearing activity should be avoided for about 48 hours.
- Glucocorticoids—injected in or around affected joints to relieve symptoms; no more than two to three injections should be administered in one year.
- Misoprostol or omeprazole—taken together with an NSAID may reduce ulcers and gastrointestinal bleeding associated with NSAID use
Surgery and Other ProceduresSurgery is usually only considered as a last resort for OA. Surgical options include:
- Arthroscopic debridement and lavage (using a lighted instrument to examine the interior of a joint, remove dead tissue, and wash the joint) may reduce symptoms
- Osteotomy (removal of all or part of the bone; loose fragments that may be causing symptoms are removed at the same time) may alleviate pain and inflammation in people with moderately advanced knee or hip OA.
- Arthrodesis (fusion of joints) may be considered for the spine and small joints of the wrist, hand, and foot to reduce pain. Fusion of the bone, however, eliminates movement of that joint.
- Arthroplasty (joint replacement) is used for people with severe and advanced OA who have not improved from any other treatments. This procedure works best for older people because artificial joints typically last only 20 years.
Nutrition and Dietary SupplementsGlucosamine 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:
- 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
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:
- 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
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.
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:
- Diminished morning stiffness
- Decreased pain
- Reduced swelling
- Improved range of motion
- Increased walking pace
- Improved symptoms
- Few side effects
- No negative influences on cartilage production (unlike NSAIDs)
- Reduced risk for relapse
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 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:
- Vitamin A and beta-carotene
- Vitamin C
- Vitamin E
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
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:
- Decreased joint stiffness and pain
- Increased grip strength
- Enhanced walking pace
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.
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
HerbsHerbal 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)
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.
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
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.
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.
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
Massage and Physical TherapyPhysical 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:
- Less stiffness
- Reduced pain
- Improved functional ability
- Improved walking distance
- Less need for knee surgery one year later
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:
- Improving range of joint motion
- Increasing muscle strength
- Eliminating muscle spasm
- Enhancing functional mobility
- Easing pain
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
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.
HomeopathyAlthough 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).
- Calcarea carbonica (carbonate of lime or calcium carbonate)
- Bryonia (wild hops)
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.
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.
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)
Traditional Chinese MedicineTai 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
- Overall sense of quality of life
- Diminished feelings of stress/tension
- Increased satisfaction with general health
- Decreased fatigue
- Easier self management of arthritis symptoms
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 ComplicationsComplications 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
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