Arthritis of the Knee
Causes, Symptoms and Treatment

Knee Arthritis Guide


Arthritis of the Knee


What Is Knee Arthritis?
What Are The Symptoms?
What Are The Causes?
How Is It Diagnosed?
How Is It Treated?
How Much Does Knee Replacement Surgery Cost?

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Guide to Arthritis
Bones and Joint Problems

What Is Knee Arthritis?

Arthritis is a general term for inflammation of one or more of the body’s joints. A joint is the junction where two bones meet and it is responsible the movement of body parts. Inflammation can occur in one specific area of the body, such as arthritis of the shoulder or the knee, or it can occur throughout the body. Although there are hundreds of different types of arthritis, the two most likely to affect the knee are osteoarthritis (majority of cases) and rheumatoid arthritis (RA):

Osteoarthritis Of The Knee

Over 10 million Americans suffer knee osteoarthritis and it one of the most common causes of disability in the country. Osteoarthritis is a degenerative joint disease which over a number of years wears away the cartilage (cushion layer) between the bones. Initially the cartilage begins to show tiny cracks and as time progresses it can wear thin and loses its flexibility. The weaker its condition the more prone it becomes to wear and tear injury. At the same time, the thick fluid which surrounds the joint, called synovial fluid, becomes thinner and loses its ability to lubricate and ease movement. Eventually the bones are left unprotected and start rubbing against each other. Osteoarthritis can cause inflammation, pain and eventually restricted movement of the knee. It can lead to stiffness when walking or standing and a grating sensation when the knee is used.

Rheumatoid Arthritis Of The Knee

Although RA typically affects the smaller joints of the body such as the hands and feet, it can also occur in the knee. Typically it affects both knees and not just one and 75 percent of cases are female. Where osteoarthritis is considered mechanical 'wear and tear', RA is an autoimmune disease which causes inflammation of the joints leading to permanent long-term damage. RA causes the knee joints to become tender, swollen and warm. Although symptoms are similar to osteoarthritis, such as pain and stiffness, joint pain associated with RA tends to be more severe.

What Are The Symptoms?

• Joint becomes stiff and swollen.
• Knee becomes difficult to bend or strengthen.
• Symptoms are worse in the morning or after a period of inactivity.
• Pain increases after walking, climbing stairs or kneeling.

Additionally, other arthritis symptoms associated with RA of the knee include:
• Flu-like symptoms
• Fever
• Fatigue.

What Are The Causes?

It is not always clear why arthritis of the knee develops, but a combination of factors may be at fault. Causes of arthritis include:

All types of arthritis are more common as we age, in particular osteoarthritis which is associated with the 'wear and tear' of time. Typically knee arthritis affects patients over the age of 50.

Obesity in women: Excess body weight places extra pressure on the body's joints, in particular the hips and knees. According to the CDC, 16 percent of reported arthritis cases occur in people of who are either normal or underweight; 21 percent are overweight and 31 percent are obese. As little as 11 pounds of weight loss reduces the risk of developing knee osteoarthritis in women by 50 percent.

Lack Of Physical Activity
Nearly 44 percent of adult cases of arthritis report taking no exercise in their spare time compared with 36 percent of adults without arthritis.

Genetic studies shows that people who inherit the HLA-DRB gene are predisposed to developing RA. This means if a close relative, father, mother or sibling has arthritis of the knee, you are at increased risk of doing so as well.

Previous Injuries
Any trauma to the knee due to an accident or sports injury increases the risk of osteoarthritis in later years. This includes ligament damage, meniscus tears and fractures to the bone around the joint.

Flat Feet
Some doctors and most podiatrists believe that flat feet (Pes Planus) increases the risks of knee osteoarthritis. One study which followed a group of army recruits reported that those with flat feet developed double the rate of knee arthritis than those with normal arches.

How Is It Diagnosed?

An early diagnosis is particularly important for patients with knee arthritis as treatment in the early stages of the disease can halt or slow the deterioration process down. A doctor usually gives a diagnosis based on findings taken from a medical history, a physical exam and diagnostic tests.

Medical History
The doctor will ask about the symptoms, when they started, and if they are worse at any time of the day. Is pain more prevalent when performing certain tasks such as walking or bending? He will also want to know if there were any injuries to the knee in the past.

Physical Examination
The doctor will bend, straighten and rotate the knee checking for mobility and signs of pain. He will press the knee at certain points to feel for injury or any dislocation of bone. He may ask the patient to walk, bend or squat to assess mobility. He will note:

• Which if any motion causes pain.
• If one or both knees are affected.
• If there is any sign of swelling in the knee or surrounding area.
• Any signs of infection such as redness, warmth and fever.

Diagnostic Tests
After the physical examination the doctor may use one or more tests to determine the extent of the knee problem. The most common tests are:

X-Ray (Radiography)
An X-ray procedure gives a 2-D picture of the internal workings of the bones and surrounding tissues. It helps detect any thinning or erosion of the knee bones, or if there is any loss of joint space or fluid in the joints. It should also help determine which type of arthritis is present. As X-rays are the least expensive imaging technique, they tend to be performed more regularly.

CT or CAT Scan
This 3-D test shows muscles and ligaments more clearly than an X-ray.

Magnetic Resonance Imaging (MRI)
An MRI scan is a powerful test which is particularly good for detecting damage to soft tissues. The patient places their leg in a cylindrical chamber and energy from a magnet passes through the knee, rather than x-rays, taking images.

Blood Tests
If RA of the knee is suspected your doctor should perform some blood tests. A blood test may reveal Rheumatoid factor (RF), an antibody which is found in nearly 80 percent of people with RA. It is still found in people who do not have the disease but only where another close family member has it. See arthritis diagnosis for more details. The doctor may also withdraw (by injection) a sample of joint synovial fluid from around the knee for analysis. Most people with RA have inflammatory material in this fluid.

How Is It Treated?

Non-Surgical Treatment

Arthritis treatment: Reports show that people with arthritis have twice as many unhealthy days and 3 times as many days with limited activity than those without the disease. 8 million Americans with arthritis report difficulties in stooping and bending, 6 million have problems walking, 5 million have difficulties climbing stairs and 2 million have problems participating in family or church activities. As a disease, arthritis can severely impede on a person's quality of life. For this reason active participation by both patient and doctor in a treatment plan is critical. Although arthritis of the knee cannot be cured, symptoms can be managed by lifestyle modifications, medications and supportive devices.

Lifestyle Modification

Weight Loss
Patients who are overweight or obese will be advised to lose weight. Every 1 pound of weight loss will result in 3 pounds of stress reduction on the knee joints (which is also an important consideration for those with hip arthritis). Furthermore, if surgery is a consideration in the future, losing weight will reduce the risk of serious complications such as blood clots.

The CDC reports that older adults with knee osteoarthritis who participate in moderate physical activity at least 3 times a week can reduce the risk of disability by 47 percent. Discuss a personalized exercise plan with your physician or physical therapist. See also: Natural treatment for arthritis as well as books on arthritis for published self-help guides.

Supportive Devices - Braces
Your doctor may recommend an unloader knee brace. This is a highly specialized brace that reduces pressure on the knee joint. Special hinges on the brace change the angle of the knee joint, shifting weight to the healthy part of the knee. Prices on average range from $500 to $800 and they are not usually covered by insurance. Another type of brace is called a 'support' or sleeve brace. The most comfortable have a hole in the front which helps to reduce pressure on the knee. They cost on average $70. Most studies show that people with arthritis of the knee can walk for longer distances more comfortably when they use a brace. See also arthritis equipment for other aids.


Anti-Inflammatory Drugs
These medications can help to manage pain and reduce swelling in the joint. They include ibuprofen, paracetamol, aspirin and acetaminophen which are all available over the counter. Although considered a first line of treatment, over time the body can build up an intolerance to painkillers reducing their overall effect. Anti-inflammatory drugs can react with other medications such as blood-thinners, so be sure to discuss any treatment with your doctor first.

Nonsteroidal Anti-Inflammatory Drug (NSAIDs)
These are more potent pain relievers which are available both over the counter and on prescription. Drugs include Aleve, Advil and Motrin. COX-2 inhibitor's (Mobic and Celebrex) are newer NSAIDs to the market which can help to reduce moderate pain and muscle inflammation.

Glucosamine and Chondroitin
These are supplements which may be more useful to take in the early stages of knee arthritis. Glucosamine is derived from shellfish shells and is thought to promote the repair of cartilage. Chondroitin is generally derived from cow cartilage and may help promote water retention and elasticity as well as inhibit the enzymes that destroy cartilage. Although both are natural substances they can cause side effects such as nausea, headaches and skin reactions. They need to be taken for at least 2 months before any effects are noticed.

Corticosteroid Injections
This is a powerful anti-inflammatory steroid which is injected directly into the knee joint. It can provide instant pain relief for up to 6 months and is particularly helpful is there is significant inflammation. It may be less helpful where pain is derived from arthritis that affects the mechanics of the joint.

Gold Injections
Intramuscular gold injections can reduce inflammation, swelling, pain and stiffness in the joints of people with rheumatoid arthritis of the knee. Gold (brand name Myocrisin) is a disease-modifying anti-rheumatic drug (DMARD) that contains gold, but it is not pure gold. It has the additional benefit of treating the underlying disease, which means it does more than just treat the symptoms. Unlike cortisone injections however, gold injections do not work straight away, in fact they can take up to 3 months to show benefits.

Surgical Treatment

Surgery is only considered as a last resort where more conservative therapies have failed. An orthopedic surgeon should discuss the type of knee replacement surgeries available, the risks involved and the rehabilitation protocols with you before you make a decision. The most popular surgical options include:Knee

Arthroscopic Surgery
This procedure is carried out by an orthopedic surgeon and involves inserting a small camera instrument called an arthroscope (about the size of a pencil) in to the knee joint. This allows the surgeon to review the joint in detail and repair any damage. Knee arthroscopy is typical performed to:

• Remove or repair torn meniscal cartilage.
• Trim torn pieces of articular cartilage.
• Reconstruct a torn anterior cruciate ligament.
• Remove loose pieces of bone or cartilage.
• Remove inflamed synovial tissue.

Recovery from this surgery is quicker than traditional open knee surgery and it is recommended that patients work with a physical therapist in the weeks after surgery to improve the final results.

This procedure is recommended if damage to the knee cartilage is primarily on one side of the knee. Typically it involves the medial compartment where the femoral condyle meets the top of the tibia (shinbone). It can be performed if a broken knee does not heal correctly. The surgeon realigns the joint away from the damaged area, shifting the stress of weight bearing to the healthier section of the knee. Although an osteotomy can significantly improve symptoms for several years, many people will eventually require a total knee replacement - arthroplasty.

If the knee joint is significantly diseased and your movements limited a surgeon may recommend replacement with an artificial joint (arthroplasty). If arthritis is mainly located on one side, a unicompartmental knee arthroplasty may be recommended. If both sides are affected a total joint replacement will probably be more appropriate. Results of surgery are usually very good - after 10 years 90 percent of patients are still happy with their prostheses. Implants usually have to be replaced after 15 years.

How Much Does Knee Replacement Surgery Cost?

Typically a total knee replacement surgery costs on average $35,000. Some medical facilities will offer discounts of $4,000 to $5,000 to those who are uninsured. If you are insured the surgery is normally covered by health insurance if ordered by a doctor. The average cost of Arthroscopic Knee Surgery is €11,000.

  Related Articles on Arthritis

For more related conditions of the bones, see the following:

Main causes of death in women: Top 10 diseases that kill women.
Development of the female body: adolescence to old age.
Arthritis of the Hand

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