Osteoarthritis
On this page:
This booklet is for people who have osteoarthritis, their
families, and others interested in learning more about the disorder.
The booklet describes osteoarthritis and its symptoms and contains
information about diagnosis and treatment, as well as current research
efforts supported by the National Institute of Arthritis and Musculoskeletal
and Skin Diseases (NIAMS) and other components of the National Institutes
of Health (NIH). It also discusses pain relief, exercise, and quality
of life for people with osteoarthritis. If you have further questions
after reading this booklet, you may wish to discuss them with your
doctor.
Osteoarthritis (AH-stee-oh-ar-THREYE-tis) is the most
common type of arthritis, especially among older people. Sometimes
it is called degenerative joint disease or osteoarthrosis.
Osteoarthritis is a joint disease that mostly affects
the cartilage (KAR-til-uj). Cartilage is the slippery tissue that
covers the ends of bones in a joint. Healthy cartilage allows bones
to glide over one another. It also absorbs energy from the shock of
physical movement. In osteoarthritis, the surface layer of cartilage
breaks down and wears away. This allows bones under the cartilage
to rub together, causing pain, swelling, and loss of motion of the
joint. Over time, the joint may lose its normal shape. Also, bone
spurs--small growths called osteophytes--may grow on the edges of
the joint. Bits of bone or cartilage can break off and float inside
the joint space. This causes more pain and damage.
People with osteoarthritis usually have joint pain and
limited movement. Unlike some other forms of arthritis, osteoarthritis
affects only joints and not internal organs. For example, rheumatoid
arthritis--the second most common form of arthritis--affects other
parts of the body besides the joints. It begins at a younger age than
osteoarthritis, causes swelling and redness in joints, and may make
people feel sick, tired, and (uncommonly) feverish.
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Osteoarthritis is one of the most frequent causes of physical
disability among adults. More than 20 million people in the United
States have the disease. By 2030, 20 percent of Americans--about 70
million people--will have passed their 65th birthday and will be at
risk for osteoarthritis. Some younger people get osteoarthritis from
joint injuries, but osteoarthritis most often occurs in older people.
In fact, more than half of the population age 65 or older would show
x-ray evidence of osteoarthritis in at least one joint. Both men and
women have the disease. Before age 45, more men than women have osteoarthritis,
whereas after age 45, it is more common in women.
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Osteoarthritis affects each person differently. In some
people, it progresses quickly; in others, the symptoms are more serious.
Scientists do not know yet what causes the disease, but they suspect
a combination of factors, including being overweight, the aging process,
joint injury, and stresses on the joints from certain jobs and sports
activities.
| What Areas Does Osteoarthritis
Affect?
Osteoarthritis most often occurs at the ends of
the fingers, thumbs, neck, lower back, knees, and hips. |
Osteoarthritis hurts people in more than their joints:
their finances and lifestyles also are affected.
Financial effects include
- The cost of treatment
- Wages lost because of disability.
Lifestyle effects include
- Depression
- Anxiety
- Feelings of helplessness
- Limitations on daily activities
- Job limitations
- Trouble participating in everyday personal and family joys and
responsibilities.
Despite these challenges, most people with osteoarthritis
can lead active and productive lives. They succeed by using
osteoarthritis treatment strategies, such as the following:
- Pain relief medications
- Rest and exercise
- Patient education and support programs
- Learning self-care and having a "good-health attitude."
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Most joints--the place where two moving bones come together--are
designed to allow smooth movement between the bones and to absorb
shock from movements like walking or repetitive movements. The joint
is made up of:
- Cartilage: a hard but slippery coating on the end
of each bone. Cartilage, which breaks down and wears away in osteoarthritis,
is described in more detail below.
- Joint capsule: a tough membrane sac that holds all
the bones and other joint parts together.
- Synovium (sin-O-vee-um): a thin membrane inside
the joint capsule.
- Synovial fluid: a fluid that lubricates the joint
and keeps the cartilage smooth and healthy.
- Ligaments, tendons, and muscles: tissues that keep
the bones stable and allow the joint to bend and move. Ligaments
are tough, cord-like tissues that connect one bone to another. Tendons
are tough, fibrous cords that connect muscles to bones. Muscles
are bundles of specialized cells that contract to produce movement
when stimulated by nerves.
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Usually, osteoarthritis comes on slowly. Early in the
disease, joints may ache after physical work or exercise. Osteoarthritis
can occur in any joint. Most often it occurs at the hands, knees,
hips, or spine.
Hands: Osteoarthritis of the fingers is
one type of osteoarthritis that seems to have some hereditary characteristics;
that is, it runs in families. More women than men have it, and they
develop it especially after menopause. In osteoarthritis, small, bony
knobs appear on the end joints of the fingers. They are called Heberden's
(HEB-err-denz) nodes. Similar knobs, called Bouchard's (boo-SHARDZ)
nodes, can appear on the middle joints of the fingers. Fingers can
become enlarged and gnarled, and they may ache or be stiff and numb.
The base of the thumb joint also is commonly affected by osteoarthritis.
Osteoarthritis of the hands can be helped by medications, splints,
or heat treatment.
Cartilage: The Key to Healthy Joints
Cartilage is 65 to 80 percent water. Three other components
make up the rest of cartilage tissue: collagen, proteoglycans,
and chondrocytes.
- Collagen (KAHL-uh-jen): a fibrous protein.
Collagen is also the building block of skin, tendon, bone,
and other connective tissues.
- Proteoglycans (PRO-tee-uh-GLY-kanz): a
combination of proteins and sugars. Strands of proteoglycans
and collagen weave together and form a mesh-like tissue.
This allows cartilage to flex and absorb physical shock.
- Chondrocytes (KAHN-druh-sytz): cells that
are found all through the cartilage. They mainly help
cartilage stay healthy and grow. Sometimes, however, they
release substances called enzymes that destroy collagen
and other proteins. Researchers are trying to learn more
about chondrocytes.
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Knees: The knees are the body's primary
weight-bearing joints. For this reason, they are among the joints
most commonly affected by osteoarthritis. They may be stiff, swollen,
and painful, making it hard to walk, climb, and get in and out of
chairs and bathtubs. If not treated, osteoarthritis in the knees can
lead to disability. Medications, weight loss, exercise, and walking
aids can reduce pain and disability. In severe cases, knee replacement
surgery may be helpful.
Hips: Osteoarthritis in the hip can cause
pain, stiffness, and severe disability. People may feel the pain in
their hips, or in their groin, inner thigh, buttocks, or knees. Walking
aids, such as canes or walkers, can reduce stress on the hip. Osteoarthritis
in the hip may limit moving and bending. This can make daily activities
such as dressing and foot care a challenge. Walking aids, medication,
and exercise can help relieve pain and improve motion. The doctor
may recommend hip replacement if the pain is severe and not relieved
by other methods.
Spine: Stiffness and pain in the neck or
in the lower back can result from osteoarthritis of the spine. Weakness
or numbness of the arms or legs also can result. Some people feel
better when they sleep on a firm mattress or sit using back support
pillows. Others find it helps to use heat treatments or to follow
an exercise program that strengthens the back and abdominal muscles.
In severe cases, the doctor may suggest surgery to reduce pain and
help restore function.
The Warning Signs of Osteoarthritis
- Steady or intermittent pain in a joint
- Stiffness in a joint after getting out of bed
or sitting for a long time
- Swelling or tenderness in one or more
joints
- A crunching feeling or the sound of bone rubbing
on bone
- Hot, red, or tender? Probably not osteoarthritis.
Check with your doctor about other causes, such as rheumatoid
arthritis.
- Pain? Not always. In fact, only a third of people
whose x rays show evidence of osteoarthritis report pain
or other symptoms.
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No single test can diagnose osteoarthritis. Most doctors
use a combination of the following methods to diagnose the disease
and rule out other conditions:
Clinical history: The doctor begins by asking
the patient to describe the symptoms, and when and how the condition
started. Good doctor-patient communication is important. The doctor
can give a better assessment if the patient gives a good description
of pain, stiffness, and joint function, and how they have changed
over time. It also is important for the doctor to know how the condition
affects the patient's work and daily life. Finally, the doctor also
needs to know about other medical conditions and whether the patient
is taking any medicines.
Physical examination: The doctor will check
the patient's general health, including checking reflexes and muscle
strength. Joints bothering the patient will be examined. The doctor
will also observe the patient's ability to walk, bend, and carry out
activities of daily living.
X rays: Doctors take x rays to see how much
joint damage has been done. X rays of the affected joint can show
such things as cartilage loss, bone damage, and bone spurs. But there
often is a big difference between the severity of osteoarthritis as
shown by the x ray and the degree of pain and disability felt by the
patient. Also, x rays may not show early osteoarthritis damage, before
much cartilage loss has taken place.
Other tests: The doctor may order blood
tests to rule out other causes of symptoms. Another common test is
called joint aspiration, which involves drawing fluid from the joint
for examination.
It usually is not difficult to tell if a patient has osteoarthritis.
It is more difficult to tell if the disease is causing the patient's
symptoms. Osteoarthritis is so common--especially in older people--that
symptoms seemingly caused by the disease actually may be due to other
medical conditions. The doctor will try to find out what is causing
the symptoms by ruling out other disorders and identifying conditions
that may make the symptoms worse. The severity of symptoms in osteoarthritis
is influenced greatly by the patient's attitude, anxiety, depression,
and daily activity level.
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Most successful treatment programs involve a combination
of treatments tailored to the patient's needs, lifestyle, and health.
Osteoarthritis treatment has four general goals:
- Improve joint care through rest and exercise.
- Maintain an acceptable body weight.
- Control pain with medicine and other measures.
- Achieve a healthy lifestyle.
Treatment Approaches to Osteoarthritis
- Exercise
- Weight control
- Rest and joint care
- Pain relief techniques
- Medicines
- Alternative therapies
- Surgery
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Osteoarthritis treatment plans often include ways to manage
pain and improve function. Such plans can involve exercise, rest and
joint care, pain relief, weight control, medicines, surgery, and nontraditional
treatment approaches.
Exercise: Research shows that exercise is
one of the best treatments for osteoarthritis. Exercise can improve
mood and outlook, decrease pain, increase flexibility, improve the
heart and blood flow, maintain weight, and promote general physical
fitness. Exercise is also inexpensive and, if done correctly, has
few negative side effects. The amount and form of exercise will depend
on which joints are involved, how stable the joints are, and whether
a joint replacement has already been done. (See
Be a Winner! Practice Self-Care and Keep a "Good-Health Attitude.")
| On the Move: Fighting Osteoarthritis With
Exercise
You can use exercises to keep strong and limber, extend
your range of movement, and reduce your weight.Some different
types of exercise include the following:
Strength exercises: These can be performed with exercise
bands, inexpensive devices that add resistance.
Aerobic activities: These keep your lungs and circulation
systems in shape.
Range of motion activities: These keep your joints
limber.
Agility exercises: These can help you maintain daily
living skills.
Neck and back strength exercises: These can help
you keep your spine strong and limber.
Ask your doctor or physical therapist what exercises
are best for you. Ask for guidelines on exercising when
a joint is sore or if swelling is present. Also, check if
you should (1) use pain-relieving drugs, such as analgesics
or anti-inflammatories (also called NSAIDs), to make exercising
easier, or (2) use ice afterwards. |
Rest and joint care: Treatment plans include
regularly scheduled rest. Patients must learn to recognize the body's
signals, and know when to stop or slow down, which prevents pain caused
by overexertion. Some patients find that relaxation techniques, stress
reduction, and biofeedback help. Some use canes and splints to protect
joints and take pressure off them. Splints or braces provide extra
support for weakened joints. They also keep the joint in proper position
during sleep or activity. Splints should be used only for limited
periods because joints and muscles need to be exercised to prevent
stiffness and weakness. An occupational therapist or a doctor can
help the patient get a properly fitting splint.
Nondrug pain relief: People with osteoarthritis
may find nondrug ways to relieve pain. Warm towels, hot packs, or
a warm bath or shower to apply moist heat to the joint can relieve
pain and stiffness. In some cases, cold packs (a bag of ice or frozen
vegetables wrapped in a towel can relieve pain or numb the sore area.
(Check with a doctor or physical therapist to find out if heat or
cold is the best treatment.) Water therapy in a heated pool or whirlpool
also may relieve pain and stiffness. For osteoarthritis in the knee,
patients may wear insoles or cushioned shoes to redistribute weight
and reduce joint stress.
Weight control: Osteoarthritis patients
who are overweight or obese need to lose weight. Weight loss can reduce
stress on weight-bearing joints and limit further injury. A dietitian
can help patients develop healthy eating habits. A healthy diet and
regular exercise help reduce weight.
Medicines: Doctors prescribe medicines to
eliminate or reduce pain and to improve functioning. Doctors consider
a number of factors when choosing medicines for their patients with
osteoarthritis. Two important factors are the intensity of the pain
and the potential side effects of the medicine. Patients must use
medicines carefully and tell their doctors about any changes that
occur.
The following types of medicines are commonly used in
treating osteoarthritis:
- Acetaminophen: Acetaminophen is a pain reliever
(for example, Tylenol*)
that does not reduce swelling. Acetaminophen does not irritate the
stomach and is less likely than nonsteroidal anti-inflammatory drugs
(NSAIDs) to cause long-term side effects. Research has shown that
acetaminophen relieves pain as effectively as NSAIDs for many patients
with osteoarthritis.
Warning: People with liver disease, people who drink alcohol
heavily, and those taking blood- thinning medicines or NSAIDs should
use acetaminophen with caution.
* Note: Brand names included in this
booklet are provided as examples only. Their inclusion does not
mean they are endorsed by the National Institutes of Health or
any other Government agency. Also, if a certain brand name is
not mentioned, this does not mean or imply that the product is
unsatisfactory.
- NSAIDs (nonsteroidal anti-inflammatory drugs): Many
NSAIDs are used to treat osteoarthritis. Patients can buy some over
the counter (for example, aspirin, Advil, Motrin IB, Aleve, ketoprofen).
Others require a prescription. All NSAIDs work similarly: they fight
inflammation and relieve pain. However, each NSAID is a different
chemical, and each has a slightly different effect on the body.
Side effects: NSAIDs can cause stomach irritation
or, less often, they can affect kidney function. The longer a
person uses NSAIDs, the more likely he or she is to have side
effects, ranging from mild to serious. Many other drugs cannot
be taken when a patient is being treated with NSAIDs because NSAIDs
alter the way the body uses or eliminates these other drugs. Check
with your health care provider or pharmacist before you take NSAIDs
in addition to another medication. Also, NSAIDs sometimes are
associated with serious gastrointestinal problems, including ulcers,
bleeding, and perforation of the stomach or intestine. People
over age 65 and those with any history of ulcers or gastrointestinal
bleeding should use NSAIDs with caution.
COX-2 inhibitors: Several new NSAIDs--valdecoxib
(Bextra), celecoxib (Celebrex), and rofecoxib (Vioxx)--from a
class of drugs known as COX-2 inhibitors are now being used to
treat osteoarthritis. These medicines reduce inflammation similarly
to traditional NSAIDs, but they cause fewer gastrointestinal side
effects. However, these medications occasionally are associated
with harmful reactions ranging from mild to severe. (See Current
Research.)
- Other medications: Doctors may prescribe several
other medicines for osteoarthritis, including the following:
Topical pain-relieving creams, rubs, and sprays
(for example, capsaicin cream), which are applied directly to
the skin.
Mild narcotic painkillers, which--although
very effective--may be addictive and are not commonly used.
Corticosteroids, powerful anti-inflammatory
hormones made naturally in the body or manmade for use as medicine.
Corticosteroids may be injected into the affected joints to temporarily
relieve pain. This is a short-term measure, generally not recommended
for more than two or three treatments per year. Oral corticosteroids
should not be used to treat osteoarthritis.
Hyaluronic acid, a medicine for joint injection,
used to treat osteoarthritis of the knee. This substance is a
normal component of the joint, involved in joint lubrication and
nutrition.
Questions To Ask Your Doctor or Pharmacist
About Medicines
- How often should I take this medicine?
- Should I take this medicine with food or between meals?
- What side effects can I expect?
- Should I take this medicine with the other prescription
medicines I take?
- Should I take this medicine with the over-the-counter
medicines I take?
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Most medicines used to treat osteoarthritis have side
effects, so it is important for people to learn about the medicines
they take. Even nonprescription drugs should be checked. Several groups
of patients are at high risk for side effects from NSAIDs, such as
people with a history of peptic ulcers or digestive tract bleeding,
people taking oral corticosteroids or anticoagulants (blood thinners),
smokers, and people who consume alcohol. Some patients may be able
to help reduce side effects by taking some medicines with food. Others
should avoid stomach irritants such as alcohol, tobacco, and caffeine.
Some patients try to protect their stomachs by taking other medicines
that coat the stomach or block stomach acids. These measures help,
but they are not always completely effective.
Surgery: For many people, surgery helps
relieve the pain and disability of osteoarthritis. Surgery may be
performed to
- Remove loose pieces of bone and cartilage from the joint if they
are causing mechanical symptoms of buckling or locking
- Resurface (smooth out) bones
- Reposition bones
- Replace joints.
Surgeons may replace affected joints with artificial joints
called prostheses. These joints can be made from metal alloys, high-density
plastic, and ceramic material. They can be joined to bone surfaces
by special cements. Artificial joints can last 10 to 15 years or longer.
About 10 percent of artificial joints may need revision. Surgeons
choose the design and components of prostheses according to their
patient's weight, sex, age, activity level, and other medical conditions.
The decision to use surgery depends on several things.
Both the surgeon and the patient consider the patient's level of disability,
the intensity of pain, the interference with the patient's lifestyle,
the patient's age, and occupation. Currently, more than 80 percent
of osteoarthritis surgery cases involve replacing the hip or knee
joint. After surgery and rehabilitation, the patient usually feels
less pain and swelling, and can move more easily.
Nontraditional Approaches: Among the alternative
therapies used to treat osteoarthritis are the following:
- Acupuncture: Some people have found pain relief using acupuncture
(the use of fine needles inserted at specific points on the skin).
Preliminary research shows that acupuncture may be a useful component
in an osteoarthritis treatment plan for some patients. (See Current
Research.)
- Folk remedies: Some patients seek alternative therapies
for their pain and disability. Some of these alternative therapies
have included wearing copper bracelets, drinking herbal teas, and
taking mud baths. While these practices are not harmful, some can
be expensive. They also cause delays in seeking medical treatment.
To date, no scientific research shows these approaches to be helpful
in treating osteoarthritis.
- Nutritional supplements: Nutrients such as glucosamine
and chondroitin sulfate have been reported to improve the symptoms
of people with osteoarthritis, as have certain vitamins. Additional
studies are being carried out to further evaluate these claims.
(See Current
Research.)
Health Professionals Who
Treat Osteoarthritis
Many types of health professionals care for people with osteoarthritis:
- Primary care physicians. Doctors who treat patients
before they are referred to other specialists in the health
care system.
- Rheumatologists. Medical doctors who specialize
in treating arthritis and related conditions that affect
joints, muscles, and bones.
- Orthopaedists. Doctors who specialize in treatment
of and surgery for bone and joint diseases.
- Physical therapists. Health professionals who
work with patients to improve joint function.
- Occupational therapists. Health professionals
who teach ways to protect joints, minimize pain, and conserve
energy.
- Dietitians. Health professionals who teach ways
to use a good diet to improve health and maintain a healthy
weight.
- Nurse educators. Nurses who specialize in helping patients
understand their overall condition and implement their
treatment plans.
- Physiatrists (rehabilitation specialists). Doctors
who help patients make the most of their physical potential.
- Licensed acupuncture therapists. Health professionals
who reduce pain and improve physical functioning by inserting
fine needles into the skin at various points on the body.
- Psychologists. Health professionals who help
patients cope with difficulties in the home and workplace
resulting from their medical conditions.
- Social workers. Professionals who assist patients
with social challenges caused by disability, unemployment,
financial hardships, home health care, and other needs
resulting from their medical conditions.
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People with osteoarthritis can enjoy good health despite
having the disease. How? By learning self-care skills and developing
a "good-health attitude."
Self-care is central to successfully managing the pain
and disability of osteoarthritis. People have a much better chance
of having a rewarding lifestyle when they educate themselves about
the disease and take part in their own care. Working actively with
a team of health care providers enables people with the disease to
minimize pain, share in decisionmaking about treatment, and feel a
sense of control over their lives. Research shows that people with
osteoarthritis who take part in their own care report less pain and
make fewer doctor visits. They also enjoy a better quality of life.
Self-Management Programs Do Help
People with osteoarthritis find that self-management programs
help them
- Understand the disease
- Reduce pain while remaining active
- Cope physically, emotionally, and mentally
- Have greater control over the disease
- Build confidence in their ability to live an active,
independent life.
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Self-Help and Education Programs: Three
kinds of programs help people learn about osteoarthritis, learn self-care,
and improve their good-health attitude. These programs include
- Patient education programs
- Arthritis self-management programs
- Arthritis support groups.
These programs teach people about osteoarthritis, its
treatments, exercise and relaxation, patient and health care provider
communication, and problem solving. Research has shown that these
programs have clear and long-lasting benefits.
Exercise: Regular physical activity plays
a key role in self-care and wellness. Two types of exercise are important
in osteoarthritis management. The first type, therapeutic exercises,
keep joints working as well as possible. The other type, aerobic conditioning
exercises, improve strength and fitness, and control weight. Patients
should be realistic when they start exercising. They should learn
how to exercise correctly, because exercising incorrectly can cause
problems.
Most people with osteoarthritis exercise best when their
pain is least severe. Start with an adequate warmup and begin exercising
slowly. Resting frequently ensures a good workout. It also reduces
the risk of injury. A physical therapist can evaluate how a patient's
muscles are working. This information helps the therapist develop
a safe, personalized exercise program to increase strength and flexibility.
Many people enjoy sports or other activities in their
exercise program. Good activities include swimming and aquatic exercise,
walking, running, biking, cross-country skiing, and using exercise
machines and exercise videotapes.
People with osteoarthritis should check with their doctor
or physical therapist before starting an exercise program. Health
care providers will suggest what exercises are best for you, how to
warm up safely, and when to avoid exercising a joint affected by arthritis.
Pain medications and applying ice after exercising may make exercising
easier.
| Exercises for Osteoarthritis
People with osteoarthritis should do different
kinds of exercise for different benefits to the body. |
Body, Mind, Spirit: Making the most of good
health requires careful attention to the body, mind, and spirit. People
with osteoarthritis must plan and develop daily routines that maximize
their quality of life and minimize disability. They also need to evaluate
these routines periodically to make sure they are working well.
Good health also requires a positive attitude. People
must decide to make the most of things when faced with the challenges
of osteoarthritis. This attitude--a good-health mindset--doesn't just
happen. It takes work, every day. And with the right attitude, you
will achieve it.
Enjoy a "Good-Health Attitude"
- Focus on your abilities instead of disabilities.
- Focus on your strengths instead of weaknesses.
- Break down activities into small tasks that you can
manage.
- Incorporate fitness and nutrition into daily routines.
- Develop methods to minimize and manage stress.
- Balance rest with activity.
- Develop a support system of family, friends, and health
professionals.
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The leading role in osteoarthritis research is played
by the National Institute of Arthritis and Musculoskeletal and Skin
Diseases (NIAMS), within the National Institutes of Health (NIH).
The NIAMS funds many researchers across the United States to study
osteoarthritis. It has established a Specialized Center of Research
devoted to osteoarthritis. Also, many researchers study arthritis
at NIAMS Multipurpose Arthritis and Musculoskeletal Diseases Centers
and Multidisciplinary Clinical Research Centers. These centers conduct
basic, laboratory, and clinical research aimed at understanding the
causes, treatment options, and prevention of arthritis and musculoskeletal
diseases. Center researchers also study epidemiology, health services,
and professional, patient, and public education. The NIAMS also supports
multidisciplinary clinical research centers that expand clinical studies
for diseases like osteoarthritis.
For years, scientists thought that osteoarthritis was
simply a disease of "wear and tear" that occurred in joints as people
got older. In the last decade, however, research has shown that there
is more to the disorder than aging alone. The production, maintenance,
and breakdown of cartilage, as well as bone changes in osteoarthritis,
are now seen as a series or cascade of events. Many researchers are
trying to discover where in that cascade of events things go wrong.
By understanding what goes wrong, they hope to find new ways to prevent
or treat osteoarthritis. Some key areas of research are described
below.
Animal Models: Animals help researchers
understand how diseases work and why they occur. Animal models help
researchers learn many things about osteoarthritis, such as what happens
to cartilage, how treatment strategies might work, and what might
prevent the disease. Animal models also help scientists study osteoarthritis
in very early stages before it causes detectable joint damage.
Diagnostic Tools: Some scientists want to
find ways to detect osteoarthritis at earlier stages so that they
can treat it earlier. They seek specific abnormalities in the blood,
joint fluid, or urine of people with the disease. Other scientists
use new technologies to analyze the differences between the cartilage
from different joints. For example, many people have osteoarthritis
in the knees or hips, but few have it in the ankles. Can ankle cartilage
be different? Does it age differently? Answering these questions will
help us understand the disease better.
Genetics Studies: Researchers suspect that
inheritance plays a role in 25 to 30 percent of osteoarthritis cases.
Researchers have found that genetics may play a role in approximately
40 to 65 percent of hand and knee osteoarthritis cases. They suspect
inheritance might play a role in other types of osteoarthritis, as
well. Scientists have identified a mutation (a gene defect) affecting
collagen, an important part of cartilage, in patients with an inherited
kind of osteoarthritis that starts at an early age. The mutation weakens
collagen protein, which may break or tear more easily under stress.
Scientists are looking for other gene mutations in osteoarthritis.
Recently, researchers found that the daughters of women who have knee
osteoarthritis have a significant increase in cartilage breakdown,
thus making them more susceptible to disease. In the future, a test
to determine who carries the genetic defect (or defects) could help
people reduce their risk for osteoarthritis with lifestyle adjustments.
Tissue Engineering: This technology involves
removing cells from a healthy part of the body and placing them in
an area of diseased or damaged tissue in order to improve certain
body functions. Currently, it is used to treat small traumatic injuries
or defects in cartilage, and, if successful, could eventually help
treat osteoarthritis. Researchers at the NIAMS are exploring three
types of tissue engineering. The two most common methods being studied
today include cartilage cell replacement and stem cell transplantation.
The third method is gene therapy.
- Cartilage cell replacement: In this procedure, researchers
remove cartilage cells from the patient's own joint and then clone
or grow new cells using tissue culture and other laboratory techniques.
They then inject the newly grown cells into the patient's joint.
Patients with cartilage cell replacement have fewer symptoms of
osteoarthritis. Actual cartilage repair is limited, however.
- Stem cell transplantation: Stem cells are primitive cells
that can transform into other kinds of cells, such as muscle or
bone cells. They usually are taken from bone marrow. In the future,
researchers hope to insert stem cells into cartilage, where the
cells will make new cartilage. If successful, this process could
be used to repair damaged cartilage and avoid the need for surgical
joint replacements with metal or plastics.
- Gene therapy: Scientists are working to genetically engineer
cells that would inhibit the body chemicals, called enzymes, that
may help break down cartilage and cause joint damage. In gene therapy,
cells are removed from the body, genetically changed, and then injected
back into the affected joint. They live in the joint and protect
it from damaging enzymes.
Comprehensive Treatment Strategies: Effective
treatment for osteoarthritis takes more than medicine or surgery.
Getting help from a variety of care professionals often can improve
patient treatment and self-care. (See Health
Professionals Who Treat Osteoarthritis.) Research shows that adding
patient education and social support is a low-cost, effective way
to decrease pain and reduce the amount of medicine used.
Exercise plays a key part in comprehensive treatment.
Researchers are studying exercise in greater detail and finding out
just how to use it in treating or preventing osteoarthritis. For example,
several scientists have studied knee osteoarthritis and exercise.
Their results included the following:
- Strengthening the thigh muscle (quadriceps) can relieve symptoms
of knee osteoarthritis and prevent more damage.
- Walking can result in better functioning, and the more you walk,
the farther you will be able to walk.
- People with knee osteoarthritis who were active in an exercise
program feel less pain. They also function better.
Research has shown that losing extra weight can help people
who already have osteoarthritis. Moreover, overweight or obese people
who do not have osteoarthritis may reduce their risk of developing
the disease by losing weight.
Using NSAIDs: Many people who have osteoarthritis
have persistent pain despite taking simple pain relievers such as
acetaminophen. Some of these patients take NSAIDs instead. Health
care providers are concerned about long-term NSAID use because it
can lead to an upset stomach, heartburn, nausea, and more dangerous
side effects, such as ulcers.
Scientists are working to design and test new, safer NSAIDs.
One example currently available is a class of selective NSAIDs called
COX-2 inhibitors. Traditional NSAIDs prevent inflammation by blocking
two related enzymes in the body called COX-1 and COX-2. The gastrointestinal
side effects associated with traditional NSAIDs seems to be associated
mainly with blocking the COX-1 enzyme, which helps protect the stomach
lining. The new selective COX-2 inhibitors, however, primarily block
the COX-2 enzyme, which helps control inflammation in the body. As
a result, COX-2 inhibitors reduce pain and inflammation but are less
likely than traditional NSAIDs to cause gastrointestinal ulcers and
bleeding. However, research shows that some COX-2 inhibitors may not
protect against heart disease as well as traditional NSAIDs, so check
with your doctor if you have concerns.
Drugs to Prevent Joint Damage: No treatment
actually prevents osteoarthritis or reverses or blocks the disease
process once it begins. Present treatments just relieve the symptoms.
Researchers are looking for drugs that would prevent, slow down, or
reverse joint damage. One experimental antibiotic drug, doxycycline,
may stop certain enzymes from damaging cartilage. The drug has shown
some promise in clinical studies, but more studies are needed. Researchers
also are studying growth factors and other natural chemical messengers.
These potential medicines may be able to stimulate cartilage growth
or repair.
Acupuncture: During an acupuncture treatment,
a licensed acupuncture therapist inserts very fine needles into the
skin at various points on the body. Scientists think the needles stimulate
the release of natural, pain-relieving chemicals produced by the brain
or the nervous system. Researchers are studying acupuncture treatment
of patients who have knee osteoarthritis. Early findings suggest that
traditional Chinese acupuncture is effective for some patients as
an additional therapy for osteoarthritis, reducing pain and improving
function.
Nutritional Supplements: Nutritional supplements
are often reported as helpful in treating osteoarthritis. Such reports
should be viewed with caution, however, since very few studies have
carefully evaluated the role of nutritional supplements in osteoarthritis.
- Glucosamine and chondroitin sulfate: Both of these nutrients
are found in small quantities in food and are components of normal
cartilage. Scientific studies on these two nutritional supplements
have not yet shown that they affect the disease. They may relieve
symptoms and reduce joint damage in some patients, however. The
National Center for Complementary and Alternative Medicine at the
NIH is supporting a clinical trial to test whether glucosamine,
chondroitin sulfate, or the two nutrients in combination reduce
pain and improve function. Patients using this therapy should do
so only under the supervision of their doctor, as part of an overall
treatment program with exercise, relaxation, and pain relief.
- Vitamins D, C, E, and beta carotene: The progression of
osteoarthritis may be slower in people who take higher levels of
vitamin D, C, E, or beta carotene. More studies are needed to confirm
these reports.
Hyaluronic Acid: Injecting this substance
into the knee joint provides long-term pain relief for some people
with osteoarthritis. Hyaluronic acid is a natural component of cartilage
and joint fluid. It lubricates and absorbs shock in the joint. The
Food and Drug Administration (FDA) approved this therapy for patients
with osteoarthritis of the knee who do not get relief from exercise,
physical therapy, or simple analgesics. Researchers are presently
studying the benefits of using hyaluronic acid to treat osteoarthritis.
Estrogen: In studies of older women, scientists
found a lower risk of osteoarthritis in women who had used oral estrogens
for hormone replacement therapy. The researchers suspect having low
levels of estrogen could increase the risk of developing osteoarthritis.
Additional studies are needed to answer this question.
Research is opening up new avenues of treatment for people
with osteoarthritis. A balanced, comprehensive approach is still the
key to staying active and healthy with the disease. People with osteoarthritis
should combine exercise, relaxation education, social support, and
medicines in their treatment strategies. Meanwhile, as scientists
unravel the complexities of the disease, new treatments and prevention
methods should appear. They will improve the quality of life for people
with osteoarthritis and their families.
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National
Institute of Arthritis and Musculoskeletal and Skin Diseases
National Institutes of Health
American College
of Rheumatology
American Academy of Orthopaedic
Surgeons
Arthritis Foundation
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Ankylosing Spondylitis
