Questions and Answers About
National Institute of Arthritis and
Musculoskeletal and Skin Diseases
This fact sheet contains general information about knee problems.
It includes descriptions and a diagram of the different parts of the knee,
including bones, cartilage, muscles, ligaments, and tendons. Individual
sections of the fact sheet describe the symptoms, diagnosis, and treatment of
specific types of knee injuries and conditions. (See
index.) Information is also provided on the prevention of knee
What Causes Knee Problems?
Some knee problems result from wear of parts of the knee, such as
occurs in osteoarthritis. Other problems result from injury, such as a blow to
the knee or sudden movements that strain the knee beyond its normal range of
How Can People Prevent Knee Problems?
- Some knee problems, such as those resulting from an accident,
cannot be foreseen or prevented. However, a person can prevent many knee
problems by following these suggestions:
- First warm up by walking or riding a stationary bicycle, then
do stretches before exercising or participating in sports. Stretching the
muscles in the front of the thigh (quadriceps) and back of the thigh
(hamstrings) reduces tension on the tendons and relieves pressure on the knee
- Strengthen the leg muscles by doing specific exercises (for
example, by walking up stairs or hills, or by riding a stationary bicycle). A
supervised workout with weights is another pathway to strengthening leg muscles
that benefit the knee.
- Avoid sudden changes in the intensity of exercise. Increase the
force or duration of activity gradually.
- Wear shoes that both fit properly and are in good condition to
help maintain balance and leg alignment when walking or running. Knee problems
may be caused by flat feet or overpronated feet (feet that roll inward). People
can often reduce some these problems by wearing special shoe inserts
(orthotics). Maintain appropriate weight to reduce stress on the knee. Obesity
increases the risk of degenerative (wearing) conditions such as osteoarthritis
of the knee.
What Kinds of Doctors Treat Knee Problems?
Extensive injuries and diseases of the knees are usually treated
by an orthopaedic surgeon, a doctor who has been trained in the nonsurgical and
surgical treatment of bones, joints, and soft tissues (for example, ligaments,
tendons, and muscles). Patients seeking nonsurgical treatment of arthritis of
the knee may also consult a rheumatologist (a doctor specializing in the
diagnosis and treatment of arthritis and related disorders).
What Are the Major Structures of the Knee? What Do They
The knee joint works like a hinge to bend and straighten the lower
leg. It permits a person to sit, stand, and pivot. The knee is composed of the
following parts (see diagram):
Structures of the Knee
Bones and Cartilage
The knee joint is the junction of three bonesthe femur
(thigh bone or upper leg bone), the tibia (shin bone or larger bone of the
lower leg), and the patella (kneecap). The patella is about 2 to 3 inches wide
and 3 to 4 inches long. It sits over the other bones at the front of the knee
joint and slides when the leg moves. It protects the knee and gives leverage to
The ends of the three bones in the knee joint are covered with
articular cartilage, a tough, elastic material that helps absorb shock and
allows the knee joint to move smoothly. Separating the bones of the knee are
pads of connective tissue called menisci, which are divided into two
crescent-shaped discs positioned between the tibia and femur on the outer and
inner sides of each knee. The two menisci in each knee act as shock absorbers,
cushioning the lower part of the leg from the weight of the rest of the body,
as well as enhancing stability.
There are two groups of muscles at the knee. The quadriceps muscle
comprises four muscles on the front of the thigh that work to straighten the
leg from a bent position. The hamstring muscles, which bend the leg at the
knee, run along the back of the thigh from the hip to just below the knee.
Ligaments are strong, elastic bands of tissue that connect bone to
bone. They provide strength and stability to the joint. Four ligaments connect
the femur and tibia:
- The medial collateral ligament (MCL) provides stability to the
inner (medial) aspect of the knee.
- The lateral collateral ligament (LCL) provides stability to the
outer (lateral) aspect of the knee.
- The anterior cruciate ligament (ACL), in the center of the
knee, limits rotation and the forward movement of the tibia.
- The posterior cruciate ligament (PCL), also in the center of
the knee, limits backward movement of the tibia.
Other ligaments are part of the knee capsule, which is a
protective, fiber-like structure that wraps around the knee joint. Inside the
capsule, the joint is lined with a thin, soft tissue, called synovium.
Tendons are tough cords of tissue that connect muscle to bone. In
the knee, the quadriceps tendon connects the quadriceps muscle to the patella
and provides power to extend the leg. The patellar tendon connects the patella
to the tibia. Technically, it is a ligament, but it is commonly called a
How Are Knee Problems Diagnosed?
Doctors use several methods to diagnose knee problems.
- Medical historythe patient tells the doctor details about
symptoms and about any injury, condition, or general health problem that might
be causing the pain.
- Physical examinationthe doctor bends, straightens,
rotates (turns), or presses on the knee to feel for injury and discover the
limits of movement and location of pain.
- Diagnostic teststhe doctor uses one or more tests to
determine the nature of a knee problem.
- X ray (radiography)an x-ray beam is passed through the
knee to produce a two-dimensional picture of the bones.
- Computerized axial tomography (CAT) scanx rays lasting a
fraction of a second are passed through the knee at different angles, detected
by a scanner, and analyzed by a computer. This produces a series of clear
cross-sectional images ( slices) of the knee tissues on a computer
screen. CAT scan images show soft tissues more clearly than normal x rays.
Individual images can be combined by computer to give a three-dimensional view
of the knee.
- Bone scan (radionuclide scanning)a very small amount of
radioactive material is injected into the patient's bloodstream and detected by
a scanner. This test detects blood flow to the bone and cell activity within
the bone, and can show abnormalities in these processes that may aid
- Magnetic resonance imaging (MRI)energy from a powerful
magnet (rather than x rays) stimulates tissues of the knee to produce signals
that are detected by a scanner and analyzed by computer. This creates a series
of cross-sectional images of a specific part of the knee. An MRI is
particularly sensitive for detecting damage or disease of soft tissues, such as
ligaments and muscles. As with a CAT scan, a computer can be used to produce
three-dimensional views of the knee during MRI.
- Arthroscopythe doctor manipulates a small, lighted optic
tube (arthroscope) that has been inserted into the joint through a small
incision in the knee. Images of the inside of the knee joint are projected onto
a television screen.
Index to Knee Injuries and
- Cartilage Injuries and Disorders
- Arthritis of the Knee
- Ligament Injuries
- Tendon Injuries and Disorders
- Other Knee
Cartilage Injuries and Disorders
What Is Chondromalacia?
Chondromalacia (pronounced KON-DRO-MAH-LAY-SHE-AH), also called
chondromalacia patellae, refers to softening of the articular cartilage of the
kneecap. The disorder occurs most often in young adults and may be caused by
trauma, overuse, parts out of alignment, or muscle weakness. Instead of gliding
smoothly across the lower end of the thigh bone, the kneecap rubs against it,
thereby roughening the cartilage underneath the kneecap. The damage may range
from a slight abnormality of the surface of the cartilage to a surface that has
been worn away completely to the bone. Traumatic chondromalacia occurs when a
blow to the knee cap tears off either a small piece of articular cartilage or a
large fragment containing a piece of bone (osteochondral fracture).
What Are the Symptoms of Chondromalacia? How Is It
The most frequent symptom of chondromalacia is a dull pain around
or under the kneecap that worsens when walking down stairs or hills. A person
may also feel pain when climbing stairs or during other activities when the
knee bears weight as it is straightened. The disorder is common in runners and
is also seen in skiers, cyclists, and soccer players. A patient's description
of symptoms and a followup x ray usually help the doctor make a diagnosis.
Although arthroscopy can confirm the diagnosis of chondromalacia, it is not
performed unless the condition requires extensive treatment.
How Is Chondromalacia Treated?
Many doctors recommend that patients with chondromalacia perform
low-impact exercises that strengthen muscles, particularly the inner part of
the quadriceps, without injuring joints. Swimming, riding a stationary bicycle,
and using a cross-country ski machine are acceptable as long as the knee is not
bent more than 90 degrees. Electrical stimulation may also be used to
strengthen the muscles. If these treatments fail to improve the condition, the
physician may perform arthroscopic surgery to smooth the surface of the
articular cartilage and wash out cartilage fragments that cause the joint
to catch during bending and straightening. In more severe cases of
chondromalacia, surgery may be necessary to correct the angle of the kneecap
and relieve friction involving the cartilage or to reposition parts that are
out of alignment.
Injuries to the
What Is the Cause of Injuries to the Meniscus?
The two menisci are easily injured by the force of rotating the
knee while bearing weight. A partial or total tear of a meniscus may occur when
a person quickly twists or rotates the upper leg while the foot stays still
(for example, when dribbling a basketball around an opponent or turning to hit
a tennis ball). If the tear is tiny, the meniscus stays connected to the front
and back of the knee; if the tear is large, the meniscus may be left hanging by
a thread of cartilage. The seriousness of a tear depends on its location and
What Are the Symptoms of Injury?
Generally, when people injure a meniscus, they feel some pain,
particularly when the knee is straightened. The pain may be mild, and the
person may continue activity. Severe pain may occur if a fragment of the
meniscus catches between the femur and tibia. Swelling may occur soon after
injury if blood vessels are disrupted, or swelling may occur several hours
later if the joint fills with fluid produced by the joint lining (synovium) as
a result of inflammation. If the synovium is injured, it may become inflamed
and produce fluid to protect itself. This causes swelling of the knee.
Sometimes, an injury that occurred in the past but was not treated becomes
painful months or years later, particularly if the knee is injured a second
time. After any injury the knee may click, lock, or feel weak. Symptoms of
meniscal injury may disappear on their own but frequently, symptoms persist or
return and require treatment.
How Is Meniscal Injury Diagnosed?
In addition to listening to the patient's description of the onset
of pain and swelling, the physician may perform a physical examination and take
x rays of the knee. The examination may include a test in which the doctor
flexes (bends) the leg then rotates the leg outward and inward while extending
it. Pain or an audible click suggests a meniscal tear. An MRI test may be
recommended to confirm the diagnosis. Occasionally, the doctor may use
arthroscopy to help diagnose and treat a meniscal tear.
How Is an Injured Meniscus Treated?
If the tear is minor and the pain and other symptoms go away, the
doctor may recommend a muscle-strengthening program. Exercises for meniscal
problems are best performed with initial guidance from a doctor and physical
therapist or exercise therapist. The therapist will make sure that the patient
does the exercises properly and without risk of new or repeat injury. The
following exercises after injury to the meniscus are designed to build up the
quadriceps and hamstring muscles and increase flexibility and strength.
- Warming up the joint by riding a stationary bicycle, then
straightening and raising the leg (but avoiding straightening the leg too
- Extending the leg while sitting (a weight may be worn on the
ankle for this exercise).
- Raising the leg while lying on the stomach.
- Exercising in a pool, including walking as fast as possible in
chest-deep water, performing small flutter kicks while holding onto the side of
the pool, and raising each leg to 90 degrees in chest-deep water while pressing
the back against the side of the pool.
If the tear to a meniscus is more extensive, the doctor may
perform either arthroscopic surgery or open surgery to see the extent of
injury and to repair the tear. The doctor can suture (sew) the meniscus back in
place if the patient is relatively young, the injury is in an area with a good
blood supply, and the ligaments are intact. Most young athletes are able to
return to vigorous sports with meniscus-preserving repair.
If the patient is elderly or the tear is in an area with a poor
blood supply, the doctor may cut off a small portion of the meniscus to even
the surface. In some cases, the doctor removes the entire meniscus. However,
degenerative changes, such as osteoarthritis, are more likely to develop in the
knee if the meniscus is removed. Medical researchers are currently
investigating a procedure called an allograft, in which the surgeon replaces
the meniscus with one from a cadaver. A grafted meniscus is fragile and may
shrink and tear easily. Researchers have also attempted to replace a meniscus
with an artificial one, but the procedure is even less successful than an
Recovery after surgery to repair a meniscus takes several weeks
longer and post-operative activity is slightly more restricted than when the
meniscus is removed. Nevertheless, putting weight on the joint actually fosters
recovery. Regardless of the form of surgery, rehabilitation usually includes
walking, bending the legs, and doing exercises that stretch and build up the
leg muscles. The best results of treatment for meniscal injury are obtained in
people who do not show articular cartilage changes and who have an intact
anterior cruciate ligament.
Arthritis of the
What Is Arthritis of the Knee?
Arthritis of the knee is most often osteoarthritis, a degenerative
disease where cartilage in the joint gradually wears away. In rheumatoid
arthritis, which can also affect the knees, the joint becomes inflamed and
cartilage may be destroyed.1 Arthritis not only affects joints, it may also
affect supporting structures such as muscles, tendons, and ligaments.
Osteoarthritis may be caused by excess stress on the joint, such
as from repeated injury, deformity, or if a person is overweight. It most often
affects middle-aged and older people. A young person who develops
osteoarthritis may have an inherited form of the disease or may have
experienced continuous irritation from an unrepaired torn meniscus or other
injury. Rheumatoid arthritis usually affects people at an earlier age than
What Are the Signs of Knee Arthritis and How Is It
A person who has arthritis of the knee may experience pain,
swelling, and a decrease in knee motion. A common symptom is morning stiffness
that lessens after moving around. Sometimes the knee joint locks or clicks when
the knee is bent and straightened, but these signs may also occur in other knee
disorders. The doctor may confirm the diagnosis by performing a physical
examination and taking x rays, which typically show a loss of joint space.
Blood tests may be helpful for diagnosing rheumatoid arthritis, but other tests
may be needed as well. Analysis of fluid from the knee joint may be helpful in
diagnosing some kinds of arthritis. The doctor may use arthroscopy to directly
visualize damage to cartilage, tendons, and ligaments and to confirm a
diagnosis, but arthroscopy is usually done only if a repair procedure is to be
How Is Arthritis of the Knee Treated?
Most often osteoarthritis of the knee is treated with analgesics
(pain-reducing medicines), such as aspirin or acetaminophen (Tylenol):*
nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Motrin,
Nuprin, Advil); and exercises to restore joint movement and strengthen the
knee. Losing excess weight can also help people with osteoarthritis. Rheumatoid
arthritis of the knee may require a treatment plan that includes physical
therapy and use of more powerful medications. In people with arthritis of the
knee, a seriously damaged joint may need to be surgically replaced with an
artificial one. (Note: A new procedure designed to stimulate the growth of
cartilage using a patient's own cartilage cells is being used experimentally to
repair cartilage injuries at the end of the femur at the knee. It is not a
treatment for arthritis.)
Posterior Cruciate Ligament Injury
What Are the Causes of Injury to the Cruciate
Injury to the cruciate ligaments of the knee is sometimes referred
to as a "sprain." The anterior cruciate ligament is most often stretched, torn,
or both by a sudden twisting motion (for example, when the feet are planted one
way and the knees are turned another way). The posterior cruciate ligament is
most often injured by a direct impact, such as in an automobile accident or
What Are the Symptoms of Cruciate Ligament Injury? How Is
Injury to a cruciate ligament may not cause pain. Rather, the
person may hear a popping sound, and the leg may buckle when he or she tries to
stand on it. To diagnose an injury, the doctor may perform several tests to see
if the parts of the knee stay in proper position when pressure is applied in
different directions. A thorough examination is essential to the diagnosis. An
MRI is very accurate in detecting a complete tear, but arthroscopy may be the
only reliable means of detecting a partial tear.
How Are Cruciate Ligament Tears Treated?
For an incomplete tear, the doctor may recommend that the patient
begin an exercise program to strengthen surrounding muscles. The doctor may
also prescribe a protective knee brace for the patient to wear during activity.
For a completely torn anterior cruciate ligament
in an active athlete and motivated patient, the doctor is likely
to recommend surgery. The surgeon may reattach the torn ends of the ligament or
reconstruct the torn ligament by using a piece (graft) of healthy ligament from
the patient (autograft) or from a cadaver (allograft). Although repair using
synthetic ligaments has been tried experimentally, the procedure has not
yielded as good results as use of human tissue. One of the most important
elements in a patient's successful recovery after cruciate ligament surgery is
following an exercise and rehabilitation program for 4 to 6 months that may
involve the use of special exercise equipment at a rehabilitation or sports
center. Successful surgery and rehabilitation will allow the patient to return
to a normal full lifestyle.
Medial and Lateral
Collateral Ligament Injury
What Is the Most Common Cause of Injury to the Medial
The medial collateral ligament is more easily injured than the
lateral collateral ligament. It is most often caused by a blow to the outer
side of the knee, which often happens in contact sports like football or
hockey, that stretches and tears the ligament on the inner side of the
What Are the Symptoms of Collateral Ligament Injury? How Is
When injury to the medial collateral ligament occurs, a person may
feel a pop and the knee may buckle sideways. Pain and swelling are common. A
thorough examination is essential to determine the nature and extent of injury.
To diagnose a collateral ligament injury, the doctor exerts pressure on the
side of the knee to determine the degree of pain and looseness of the joint. An
MRI is helpful in diagnosing injuries to these ligaments.
How Are Collateral Ligament Injuries Treated?
Most sprains of the collateral ligaments will heal if the patient
follows a prescribed exercise program. In addition to exercise, the doctor may
recommend that the patient apply ice packs to reduce pain and swelling and wear
a small sleeve-type brace to protect and stabilize the knee. A sprain may take
2 to 4 weeks to heal. A severely sprained or torn collateral ligament may be
accompanied by a torn anterior cruciate ligament, which usually requires
Tendon Injuries and Disorders
What Are the Causes of Tendinitis and Ruptured Tendons?
Knee tendon injuries range from tendinitis (inflammation of a
tendon) to a ruptured (torn) tendon. If a person overuses a tendon during
certain activities such as dancing, cycling, or running, the tendon stretches
like a worn-out rubber band and becomes inflamed. Movements such as trying to
break a fall may cause excessive contraction of the quadriceps muscles and tear
the quadriceps tendon above the patella or the patellar tendon below the
patella. This type of injury is most likely to happen in older people whose
tendons tend to be weaker. Tendinitis of the patellar tendon is sometimes
called jumper's knee. This is because in sports requiring jumping, such as
basketball, the muscle contraction and force of hitting the ground after a jump
strain the tendon. The tendon may become inflamed or tear after repeated
What Are the Symptoms of Tendon Injuries? How Are Injuries
People with tendinitis often have tenderness at the point where
the patellar tendon meets the bone. They also may feel pain during faster
movements, such as running, hurried walking, or jumping. A complete rupture of
the quadriceps or patellar tendon is not only painful but also makes it
difficult for a person to bend, extend, or lift the leg against gravity. If
there is not much swelling, the doctor will be able to feel a defect in the
tendon near the tear during a physical examination. An x ray will show that the
patella is lower in position than normal in a quadriceps tendon tear and higher
than normal in a patellar tendon tear. The doctor may use an MRI to confirm a
partial or total tear.
How Are Knee Tendon Injuries Treated?
Initially, the doctor may ask a patient with tendinitis to rest,
elevate, and apply ice to the knee and to take medicines such as aspirin or
ibuprofen to relieve pain and decrease inflammation and swelling. If the
quadriceps or patellar tendon is completely ruptured, a surgeon will reattach
the ends. After surgery, the patient will wear a cast for 3 to 6 weeks and use
crutches. If the tear is only partial, the doctor might apply a cast without
A partial or complete tear of a tendon requires an exercise
program as part of rehabilitation that is similar to but less vigorous than
that prescribed for ligament injuries. The goals of exercise are to restore the
ability to bend and straighten the knee and to strengthen the leg to prevent a
repeat knee injury. A rehabilitation program may last 6 months, although the
patient can return to many activities before then.
What Are the Causes of Osgood-Schlatter Disease?
Osgood-Schlatter disease is caused by repetitive stress or tension
on a part of the growth area of the upper tibia (the apophysis). It is
characterized by inflammation of the patellar tendon and surrounding soft
tissues at the point where the tendon attaches to the tibia. The disease may
also be associated with an avulsion injury, in which the tendon is stretched so
much that it tears away from the tibia and takes a fragment of bone with it.
The disease most commonly affects active young people, particularly boys
between the ages of 10 and 15, who play games or sports that include frequent
running and jumping.
What Are the Symptoms of Osgood-Schlatter Disease? How Is It
People with this disease experience pain just below the knee joint
that usually worsens with activity and is relieved by rest. A bony bump that is
particularly painful when pressed may appear on the upper edge of the tibia
(below the knee cap). Usually, motion of the knee is not affected. Pain may
last a few months and may recur until a child's growth is completed.
Osgood Schlatter disease is most often diagnosed by the symptoms.
An x ray may be normal, or show an avulsion injury, or, more typically, show
that the apophysis is in fragments.
How Is Osgood-Schlatter Disease Treated?
Usually, the disease disappears without treatment. Applying ice to
the knee when pain first begins helps relieve inflammation and is sometimes
used along with stretching and strengthening exercises. The doctor may advise
the patient to limit participation in vigorous sports. Children who wish to
continue participating in moderate or less stressful sports may need to wear
knee pads for protection and apply ice to the knee after activity. If a great
deal of pain is felt during sports activities, participation may be limited
until any remaining discomfort is tolerable.
What Causes Iliotibial Band Syndrome?
This is an overuse inflammatory condition due to friction
(rubbing) of a band of a tendon over the outer bone (lateral condyle) of the
knee. Although iliotibial band syndrome may be caused by direct injury to the
knee, it is most often caused by the stress of long-term overuse, such as
sometimes occurs in sports training.
What Are the Symptoms of Iliotibial Band Syndrome and How Is It
A person with this syndrome feels an ache or burning sensation at
the side of the knee during activity. Pain may be localized at the side of the
knee or radiate up the side of the thigh. A person may also feel a snap when
the knee is bent and then straightened. Swelling is usually absent and knee
motion is normal. The diagnosis of this disorder is usually based on the
patient's symptoms, such as pain at the lateral condyle, and exclusion of other
conditions with similar symptoms.
How Is Iliotibial Band Syndrome Treated?
Usually, iliotibial band syndrome disappears if the person reduces
activity and performs stretching exercises followed by muscle-strengthening
exercises. In rare cases when the syndrome doesn't disappear, surgery may be
necessary to split the tendon so it is not stretched too tightly over the
Other Knee Injuries
What Is Osteochondritis Dissecans?
Osteochondritis dissecans results from a loss of the blood supply
to an area of bone underneath a joint surface and usually involves the knee.
The affected bone and its covering of cartilage gradually loosen and cause
pain. A person with this disruption of the joint may eventually develop
osteoarthritis. This disorder usually arises spontaneously in an active
adolescent or a young adult. It may be due to a slight blockage of a small
artery or to an unrecognized injury or tiny fracture that damages the overlying
The bone undergoes avascular necrosis (degeneration from lack of a
blood supply). 2 The involvement of several joints or the appearance of
osteochondritis dissecans in several family members may indicate that the
disorder is inherited.
What Are the Symptoms of Osteochondritis Dissecans? How Is It
If spontaneous healing doesn't occur, cartilage eventually
separates from the diseased bone and a fragment breaks loose into the knee
joint, causing locking of the joint, weakness, and sharp pain. An x ray, MRI,
or arthroscopy can determine the condition of the cartilage and be used to
diagnose osteochondritis dissecans.
How Is Osteochondritis Dissecans Treated?
If cartilage fragments have not broken loose, a surgeon may fix
them in place with pins or screws that are sunk into the cartilage to stimulate
a new blood supply. If fragments are loose, the surgeon may scrape down the
cavity to reach fresh bone and add a bone graft and fix the fragments in
position. Fragments that cannot be mended are removed, and the cavity is
drilled or scraped to stimulate new growth of cartilage. Research is currently
being done to assess the use of cartilage cell transplants and other tissues to
treat this disorder.
Plica (pronounced PLI-KAH) syndrome occurs when plicae (bands of
remnant synovial tissue) are irritated by overuse or injury. Synovial plicae
are remnants of tissue pouches found in the early stages of fetal development.
As the fetus develops, these pouches normally combine to form one large
synovial cavity. If this process is incomplete, plicae remain as four folds or
bands of synovial tissue within the knee. Injury, chronic overuse, or
inflammatory conditions are associated with development of this syndrome.
What Are the Symptoms of Plica Syndrome? How Is It
People with this syndrome are likely to experience pain and
swelling, a clicking sensation, and locking and weakness of the knee. Because
the symptoms are similar to symptoms of some other knee problems, plica
syndrome is often misdiagnosed. Diagnosis usually depends on the exclusion of
other conditions that cause similar symptoms.
How Is Plica Syndrome Treated?
The goal of treatment is to reduce inflammation of the synovium
and thickening of the plicae. The doctor usually prescribes medicine such as
ibuprofen to reduce inflammation. The patient is also advised to reduce
activity, apply ice and compression wraps (elastic bandage) to the knee, and do
strengthening exercises. If this treatment program fails to relieve symptoms
within 3 months, the doctor may recommend arthroscopic or open surgery to
remove the plicae. A cortisone injection into the region of the plica folds
helps about half of the patients treated. The doctor can also use arthroscopy
to confirm the diagnosis and treat the problem.
Other Sources of Information on Knee Problems
- American Academy of Orthopaedic Surgeons
Rosemont, IL 60018-4262
World Wide Web address: http://www.aaos.org
publishes several brochures on the knee, including Knee Arthroscopy and
Total Knee Replacement, which doctors can obtain and give to their
patients. Single copies of two other pamphlets, Arthroscopy and Total
Joint Replacement, are available free to the public if a self-addressed,
stamped envelope is provided.
- American Physical Therapy Association
Alexandria, VA 22314
Web address: http://www.apta.org
association has published a free brochure titled Taking Care of the
- Arthritis Foundation
1330 Peach Tree Street
Atlanta, GA 30309
800/283-7800 or call your local chapter
(listed in the local telephone directory)
World Wide Web address: hhttp://www.arthritis.org
Foundation has several free brochures about coping with arthritis, taking
nonsteroid and steroid medicines, and exercise. A free brochure on protecting
your joints is titled Using Your Joints Wisely. The foundation also
provides doctor referrals.
- American College of Rheumatology/Association of Rheumatology
60 Executive Park South, Suite 150
World Wide Web address:
This national professional organization can provide referrals to
rheumatologists and allied health professionals, such as physical therapists.
One-page fact sheets are available on various forms of arthritis. Lists of
specialists by geographic area and fact sheets are also available on ACR's web
- National Arthritis and Musculoskeletal and Skin Diseases
National Institutes of
1 AMS Circle
Bethesda, MD 20892-3675
TTY: 301/ 565-2966
World Wide Web address:
Clearinghouse has additional information about some of the knee problems
described in this fact sheet, including osteoarthritis and avascular necrosis,
as well as information about total knee replacement and arthritis and exercise.
Single copies of fact sheets and information packages on these topics are
available free upon request.
*Brand names included in this fact sheet
are provided as examples only, and their inclusion does not mean that these
products are endorsed by the National Institutes of Health or any other
Government agency. Also, if a particular brand name is not mentioned, this does
not mean or imply that the product is unsatisfactory.
The NIAMS gratefully acknowledges the assistance of Frank A
Pettrone, M.D., of Arlington/Vienna,Virginia; W. Norman Scott, M.D., of Beth
Israel Medical Center in New York, New York; and James Panagis, M.D., M.P.H.,
and John H. Klippel, M.D., of the National Institutes of Health, in the
preparation and review of this fact sheet.
The National Arthritis and Musculoskeletal and
Skin Diseases Information Clearinghouse (NAMSIC) is a public service sponsored
by the NIAMS that provides health information and information sources. The
NIAMS, a part of the National Institutes of Health (NIH), leads the Federal
medical research effort in arthritis and musculoskeletal and skin diseases. The
NIAMS sponsors research and research training throughout the United States as
well as on the NIH campus in Bethesda, MD, and disseminates health and research
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