What is osteoarthritis?

Osteoarthritis is a joint disease that mostly affects the cartilage. 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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Basics: the joints and parts

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.

When a joint develops osteoarthritis, the cartilage gradually roughens and becomes thin, and the bone underneath thickens. The bone at the edge of the joint grows outwards (this forms osteophytes or bony spurs). The synovium swells slightly and may produce extra fluid, which then makes the joint swell slightly. The capsule and ligaments slowly thicken and contract, as if they were trying to stabilise the joint as it gradually changes shape. Muscles that move the joint may weaken and become thin or wasted.

In severe osteoarthritis, the cartilage can become so thin that it no longer covers the thickened bone ends. The bone ends touch and start to wear away. The loss of cartilage, the wearing of bone, and the bony overgrowth at the edges can change the shape of the joint. This forces the bones out of their normal position and causes deformity.

A common complication is where chalky deposits of calcium crystals form in the cartilage (a process called calcification or chondrocalcinosis). These calcium crystals can shake loose from the cartilage, irritate the synovium and cause the joint to become hot, red and swollen (pseudogout).

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Osteoarthritis symptoms

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.

Osteoarthritis of the hand with Heberden's nodes

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.

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Diagnosing osteoarthritis

No single test can diagnose osteoarthritis. Most doctors use a combination of the following methods to diagnose the disease and rule out other conditions:

The Warning Signs of Osteoarthritis are:
> 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.

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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How is Osteoarthritis treated?

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.

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.

Three anti-inflammatory drugs (COX-2 inhibitors), rofecoxib, celecoxib, and valdecoxib, typically used for painful conditions such as arthritis, have been withdrawn worldwide. Compared to nonsteroidal anti-inflammatory drugs such as aspirin and ibuprofen, these three cox-2 inhibitors cause fewer gastrointestinal problems but are twice as likely to lead to serious cardiovascular events, such as heart attack and stroke. If you or someone you know is still taking these drugs (yes, they are still available in Indian market), please consult your doctor for a replacement therapy. If you are not sure about the contents of your pain medication, please consult your doctor.

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Nutritional Supplements

Glucosamine and chondroitin sulfate are substances found naturally in the body. Glucosamine is a form of amino sugar that is believed to play a role in cartilage formation and repair. Chondroitin sulfate is part of a large protein molecule (proteoglycan) that gives elasticity to cartilage. Chondroitin taken along with glucosamine is believed to support the body’s natural ability to regenerate cartilage.

Past studies show that some people with mild to moderate osteoarthritis (OA) taking either glucosamine or chondroitin sulfate reported pain relief at a level similar to that of nonsteroidal anti-inflammatory drugs such as aspirin and ibuprofen. Some research indicates that the supplements might also slow cartilage damage in people with OA. Definitive results about the effects of these supplements are expected from an in-depth clinical study currently being conducted by the National Institutes of Health, USA.

The amount used in studies of glucosamine was 1500 mg per day and in studies of chondroitin sulfate, 1200 mg per day was used. Children and pregnant women should not take these supplements. They have not been studied long enough to determine their effects on a child or on a developing fetus. Diabetics should check their blood sugar levels more frequently when taking this supplement. Chondroitin sulfate is similar in structure to the blood-thinning drug heparin and the combination of chondroitin and heparin may cause bleeding in some people.

Choosing quality supplements: Because dietary supplements are unregulated, the quality and content may vary widely. If you decide to take these supplements: a) Choose products sold by large, well-established companies; b) Read the product labels carefully to make sure the ingredient lists make sense to you. If you have trouble, ask your doctor/pharmacists for help; c) Be sure to consult your doctor before deciding to try these supplements.

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Alternate therapies

Among the alternative therapies used to treat osteoarthritis are:

Acupuncture: Studies so far have shown that acupuncture can help people with osteoarthritis although it doesn’t seem to work for those with rheumatoid arthritis and related auto-immune diseases. Although acupuncture doesn’t work for everyone with arthritis, it is worth a try, particularly if other forms of treatment haven’t helped.

Prolotherapy: Prolotherapy, also called sclerosant therapy, proliferative injection therapy, and regeneration injection therapy, is a treatment that involves injections of dextrose and sodium morrhuate (extracted from shark liver) or dextrose, glycerin, and phenol into ligaments. Proponents claim that the injections trigger growth of new, healthy tissue to stabilize bones and joints, thus relieving musculoskeletal pain and stiffness. (more)

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Surgery

For many people, surgery helps relieve the pain and disability of osteoarthritis. 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. After surgery and rehabilitation, the patient usually feels less pain and swelling, and can move more easily.

Surgical interventions include, arthroscopic lavage - using a saline lavage to wash out the joint, joint realignment (realignment osteotomy), joint fusion (arthrodesis) - surgically fusing the joint to eliminate motion and joint replacement (arthroplasty).

The replacement 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.

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