What Is Osteoarthritis? What Causes Osteoarthritis?

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Main Category: Arthritis / Rheumatology
Also Included In: Bones / Orthopedics;  Pain / Anesthetics
Article Date: 10 Feb 2010 - 0:00 PDT

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Osteoarthritis, also known as degenerative arthritis degenerative joint disease, OA, or osteoarthrosis, is a form of arthritis caused by inflammation, breakdown, and the eventual loss of cartilage in the joints - the cartilage wears down over time.

Osteoarthritis is the most common type of arthritis. According to the National Health Service, UK, approximately 8.5 million people are affected by the condition. The Arthritis Foundation, USA, says that about 27 million Americans are affected.

Osteoarthritis is a progressive disease; signs and symptoms gradually worsen over time. There is no cure. However, available therapies may help with pain and swelling (inflammation), as well as keeping the patient mobile and active. Experts say that patients who take steps to actively manage their osteoarthritis are more likely to gain control over their symptoms.

Any joint in the body may be affected. However, the disease is most likely to affects the patient's:

• Hands
• Hips
• Knees
• Lower back
• Neck

Osteoarthritis has three characteristics:

• Bony growths develop around the edge of joints.
• It damages cartilage - Cartilage is the part of the joint that cushions the ends of the bones and allows easy movement of joints.
• Synovitis - there is mild inflammation of the tissues around the joints.

Osteoarthritis is more common among females than males, especially after the age of 50 years. Most commonly, it develops in people aged over 40. Younger people may also be affected; usually after an injury or as a result of another joint condition.

Some people say that osteoarthritis is an inevitable part of ageing. This is untrue. There are people well into their nineties who have no clinical or functional signs of the disease.

According to the Arthritis Foundation, USA:

• Women are more affected by osteoarthritis than men after the age of 50.
  
  
• Symptoms typically start after 40 years of age, and progress slowly.
  
  
• In America, loss of joint function due to osteoarthritis is a major cause of work disability and reduced quality of life.
  
  
• In America, arthritis and related conditions, such as osteoarthritis cost the country almost $128 billion annually in medical care and indirect expenses, including lost income and productivity.
  
  
• The average direct cost of osteoarthritis in America is about $2,800 per patient annually.
  
  
• The total annual cost of osteoarthritis per person living with the condition is about $5,700.

According to Medilexicon's medical dictionary:

Osteoarthritis is " Arthritis characterized by erosion of articular cartilage, either primary or secondary to trauma or other conditions, which becomes soft, frayed, and thinned with eburnation of subchondral bone and outgrowths of marginal osteophytes; pain and loss of function result; mainly affects weight-bearing joints, is more common in old people and animals.

What are the signs and symptoms of osteoarthritis?

A symptom is something the patient feels and reports, while a sign is something other people, such as the doctor detect. For example, pain may be a symptom while a rash may be a sign.

Osteoarthritis has as its main symptoms:

• Pain
• Problems moving affected joints.
• Stiffness - more severe on waking up in the morning, and improves within 30 minutes when the individual starts moving about.

In some cases people with osteoarthritis may have no symptoms. Symptoms are usually only felt in either one joint, or a just a few at any one time. In many cases the symptoms come on slowly.

Other signs and symptoms may include:

• Affected joints are larger than usual
• After not moving the joint for a while pain and stiffness may worsen
• Joints are warm
• Loss of muscle bulk
• Tenderness in the affected joint
• The affected joints will have a limited range of movements
• The patient may experience a grating or crackling sound/sensation in the affected joint

The knees, hips or hands are most commonly affected.

Osteoarthritis in the knees - in most cases both knees are affected, unless the osteoarthritis was caused by an injury (or another condition). The patient will experience pain when walking, especially uphill or upstairs. Knees may lock into position, making it much harder to straighten the leg. The knee may make a soft, grating sound when used.

Osteoarthritis in the hips - anything that requires movement of the hip joint causes problems, such as getting in/out of a car, or putting on one's shoes and socks.

Although pain in the hip is common, some patients with osteoarthritis in the hips experience pain in their knee (and not their hip). Less commonly, pain may be felt in the thighs, ankles and buttocks.

Typically, pain is felt whilst walking. But some people are in pain even when resting.

Osteoarthritis in the hands - three areas may be affected:

• The base of the thumb
• The top joint of the fingers (closest to the nail)
• The middle joint of the fingers

Fingers may be stiff, swollen and painful. Sometimes bumps may develop on the finger joints. In some cases, finger pain decreases and eventually goes away, while the swelling and bumps remain.

At the affected joints the fingers may bend slightly sideways. Fluid-filled lumps (cysts) may develop on the backs of the fingers; they are often painful.

A bump may develop where the base of the thumb joins the wrist. This may make writing, turning keys and opening jar-tops difficult and painful.

When to see a doctor

People who have joint stiffness and swelling that persist for more than a couple of weeks, they should see their doctor. Those already on osteoarthritis medications should contact a health care professional if they experience nausea, constipation, drowsiness, abdominal discomfort, or have black/tarry stools.

What are the risk factors for osteoarthritis?

A risk factor is something which increases the likelihood of developing a condition or disease. For example, obesity significantly raises the risk of developing diabetes type 2. Therefore, obesity is a risk factor for diabetes type 2.

• Age - individuals under the age of 40 rarely develop osteoarthritis. It typically occurs in older adults.
  
  
• Gender - females are more likely to develop osteoarthritis than males.
  
  
• Deformities of the bone(s) - patients born with defective joints or cartilage have a significantly higher risk of eventually developing osteoarthritis.
  
  
• Injuries - especially those resulting from an accident or some sports may raise the risk of developing osteoarthritis.
  
  
• Obesity - obese people whose weight-bearing joints are under a greater strain have a higher risk of developing the condition, compared to people of normal weight.
  
  
• Some jobs - especially those that involve repetitive movements that target stress on a particular joint may have a higher risk of developing osteoarthritis.
  
  
• People with other diseases and conditions may have a higher risk of developing the condition. Examples include:
  • Gout
  • Rheumatoid arthritis
  • Paget's disease of the bone
  • Septic arthritis
• Genetics - it is estimated that approximately 40% to 60% of cases of hand, hip and knee osteoarthritis may have a genetic link. The genes have not yet been identified. In other words, osteoarthritis, or a predisposition to developing the condition may be inherited.

What are the causes of osteoarthritis?

Process of wear and repair - often inaccurately referred to as the wear and tear arthritis, osteoarthritis should more aptly be called the wear and repair arthritis, because the condition is a slow repair process that the body utilizes to mend joints that have gradually become damaged.

In most cases, the repair process presents no symptoms. However, if there is a particularly traumatic injury to a joint and the body's ability to carry out proper repairs is undermined, subsequent damage to the affected joint will continue and the patient will experience symptoms.

When there is damage to cartilage - the protective surface that cushions the ends of bones in your joints and allows the joints to move smoothly - osteoarthritis occurs. The smooth surface of the cartilage becomes rough, causing irritation. If the cartilage wears down completely, the bone in the joint may be rubbing against another bone, causing damage and pain.

The joints may become knobbly where the bones start protruding, forming osteophytes (bony lumps). The bones gradually thicken and become broader, making the joints stiffer, less mobile, and painful. If fluid accumulates in the joints they will swell.

Experts are not sure why the repair process breaks down. They believe several contributory factors are involved:

• Injury - a joint may have been previously damaged because of an injury or surgical intervention.
  
  
• Overuse - a joint may have been overused after an injury or operation.
  
  
• Rheumatoid arthritis - if the joints of a patient with rheumatoid arthritis have been severely damaged, osteoarthritis can occur.

When osteoarthritis has developed because of damage or another condition, it is called secondary osteoarthritis. Secondary osteoarthritis signs and symptoms may take several years after the initial joint damage to appear.

Diagnosing osteoarthritis

A GP (general practitioner, primary care physician) will ask the patient about symptoms, as well as carrying out a physical examination. There is no current and definitive test that can diagnose osteoarthritis.

The following may help the doctor suspect osteoarthritis:

• There is joint stiffness first thing in the morning
• The joint stiffness first thing in the morning lasts no more than 30 minutes
• The pain is persistent
• The pain worsens when the affected joint is used
• The patient is over 40 to 45 years of age

If symptoms differ slightly from those mentioned above the doctor may suspect that the patient has another type of arthritis. Patients with rheumatoid arthritis also have early morning stiffness, but it lasts longer than an hour.

The GP will not usually order imaging or blood tests unless he/she wishes to rule out other conditions, such as another type of arthritis, or perhaps a fractured bone. Tests may include:

• X-rays - images may show that the cartilage is breaking down, if a narrowing space within a joint is detected. Bone spurs around a joint may also be revealed. It is not uncommon for people with no osteoarthritis symptoms to have X-ray signs of the condition.
  
  
• MRI (magnetic resonance imaging) scan - this device uses a magnetic field and radio waves to create detailed images of the inside of the body, including bone and bone cartilage. An MRI scan can help the doctor determine what is causing pain.
  
  
• Blood tests - these are usually performed in order to rule out other conditions, especially rheumatoid arthritis.
  
  
• Joint fluid analysis (arthrocentesis) - a sterile needle is used to withdraw (aspirate) fluid from an inflamed joint and then sent to the lab. If uric acid crystals are present it is more likely the patient has gout. This test can also determine whether there is inflammation or an infection.

What are the treatment options for osteoarthritis?

There is no cure for osteoarthritis. Treatment consists of exercise, manual therapy, lifestyle modification, medication and other interventions to alleviate pain and maintain joint movement.

Medications

• Acetimophen (paracetamol, Tylenol) - although this medication does not reduce inflammation, it does relieve pain, especially among patients with mild to moderate symptoms. As high doses can cause liver damage, especially if the patient regularly consumes alcohol, it is important to stay within the recommended dosage. As acetaminophen may affect how some other medications work, it is important that the patient informs the doctor if he/she is taking it.
  
  
• NSAIDs (non-steroidal anti-inflammatory drugs) - if acetimophen is not effective in controlling pain, the doctor may prescribe a stronger painkiller, which may include ibuprofen, aspirin or diclofenac.
  
  Some topical NSAIDs can be applied directly onto the affected joints (on the skin). Some OTC (over-the-counter, no prescription required) topical NSAIDs are very effective if the osteoarthritis affects the knees or hands. Not only do they ease pain, but also help reduce swelling in the joints.
  
  Patients with asthma or peptic ulcers may not be able to take NSAIDs. Patients should check with their doctor about NSAID suitability.
  
  Children under the age of 16 years should not take aspirin.
  
  If an oral NSAID is prescribed, the doctor may also prescribe a PPI (proton pump inhibitor) to be taken at the same time. NSAIDs can break down the lining of the stomach - the lining of the stomach protects against stomach acid. PPIs reduce the amount of acid by blocking the pumps (tiny ducts) in the stomach that produce it, resulting in a significantly lower risk of damage to the stomach lining. Other NSAID side effects may include tinnitus (ringing in the ears), cardiovascular problems, and liver and/or kidney damage. The risk of side effects are greater if the dose is high, or if the medication is taken long-term.
  
  
• Tramadol (Ultram) - this is a prescription centrally acting analgesic which has no anti-inflammatory effect (does not reduce swelling). However, it provides effective pain relief with fewer side effects, compared to NSAIDs. Patients may experience nausea and/or constipation. Tramadol is typically used for short-term acute flare ups. Sometimes the doctor may prescribe tramadol alongside acetaminophen for more powerful pain relief.
  
  
• Codeine or propoxyphene (Darvon) - these may be useful for more severe osteoarthritis symptoms. There is a risk of dependence - this risk is seen as small if the patient is in severe pain. Side effects may sometimes include constipation and drowsiness.
  
  
• Capsaicin cream - patients with osteoarthritis in their hands or knees who did not respond well to topical NSAIDs may be prescribed capsaicin cream. The medication blocks the nerves that send pain messages. However, the drug's effects may not be noticeable for a while; pain relief should be noticed within a couple of weeks, but this medication's full effect may not be appreciated for up to a month.
  
  A tiny amount of capsaicin cream should be applied to the affected joints four times daily (no more than once every four hours). Do not apply it to broken or inflamed skin.
  
  After use it is important to wash one's hands thoroughly. Capsaicin cream is made from chillies. If any of it gets into the patients eyes, mouth, nose or genitals it is likely to cause pain (without damage).
  
  When first applying capsaicin cream onto the skin there may be a burning sensation, this is normal. After some use that sensation goes away. Avoid having a hot bath or shower before or after applying the cream.
  
  
• Intra-articular injections (cortisone shots) - in some cases pain symptoms may be so severe that analgesics (painkillers) are not enough. In such cases the medication may be injected directly into the site of the joint. Usually, these will be injections of corticosteroids. Corticosteroids are effective for pain relief and to reduce swelling. The National Institute of Health and Clinical Excellence (NICE), UK, which decides on approved treatments for the National Health Service (NHS), does not recommend intra-articular injections of hyaluronic acid for osteoarthritis.
  
  Each joint should not be treated in this way more than three times a year. Too many intra-articular injections can damage the joint.

Treatment with a physical therapist (UK: physiotherapist)

• TENS (transcutaneous electrical nerve stimulation) - this is the application of electrical current through the skin for pain control. A TENS unit is usually connected to the skin using two or more electrodes. It works by numbing the nerves endings in the spinal cord that control pain.
  
  
• Thermotherapy - warm and cold temperatures are used to help reduce pain and stiffness in the joints. For example, a hot water bottle is filled with either hot or cold water and applied to the affected area. Some patients find this therapy helps with pain. Alternatively, hot and cold packs may be used - they are either cooled in the freezer or heated up in a microwave oven.
  
  
• Manual therapy - this treatment is performed by a physical therapist who uses stretching techniques to keep the joints flexible and supple. If the patient is not using the affected joint the muscle may weaken, further worsening osteoarthritis stiffness.

Assistive devices - in some cases osteoarthritis may cause problems with mobility. The patient may find everyday tasks difficult to do. There several devices which may help. Most doctors refer their patient to either an occupational therapist, a physical therapist, or both.

Problems with the lower limbs - people whose hips, knees or feet are affected may benefit from wearing special footwear, or shoe-insoles. Some shock-absorbing soles can reduce the pressure on the joints. Special insoles may help distribute bodyweight more evenly. Some patients may find that leg braces help.

Holding a stick or cane on the opposite side of the body to the affected leg may help.

If the patient needs to rest a painful joint a splint may help. A splint is a piece of rigid material that provides joint or bone support.

Hand problems - special devices, such as tap-turners can make everyday tasks easier. An occupational therapist is trained to help people carry out their everyday tasks more easily at home and in the workplace.

Surgery - this may sometimes help patients with osteoarthritis that affects their hips, knees, joints, and at the base of their thumbs. However, in most cases surgery is not needed, and is only usually recommended if other therapies have been ineffective, or if one of the joints is severely damaged.

The doctor will refer the patient to an orthopedic surgeon before symptoms become too severe, or before the osteoarthritis causes to much permanent damage. Examples of surgery include:

• Arthroplasty (joint replacement) - total replacement of the joint. The damaged parts are surgically removed and a prosthesis (artificial joint) made of metal and plastic is inserted. The most commonly replaced joints are the hip and knee joints. However, implants can currently replace the joints in the shoulder, finger, ankle and elbow. Arthroplasty is usually very effective, allowing the patient to use the joint actively and painlessly. Arthroplasty of the hand joints can help their appearance, as well as their function. There is a small risk of infection and bleeding. Sometimes they may come loose or wear down, and may need to be replaced (eventually).
  
  
• Arthrodesis - if a joint replacement is not an option, the joint may be surgically fixed to promote a bone fusion; the joint is realigned or stabilized. Also called artificial ankylosis, syndesis. This increases stability and reduces pain. If the joint in the ankle is fused the patient will be able to bear weight on it painlessly - however, it will have no flexibility.
  
  
• Osteotomy - the surgeon adds or removes a small section of bone either above or below the knee joint to realign the leg so that the patient's weight is no longer focused on the damaged part of the joint. This procedure may be used if the patient is too young for knee replacement surgery (arthroplasty). Although this procedure helps relieve symptoms significantly, there may be a need for knee replacement surgery later on.

Osteoarthritis self-help

There are several things patients can do to help ease the symptoms of osteoarthritis. A doctor or physical therapist should be able to offer useful advice on lifestyle changes. Some patients may only need the changes listed below to keep their symptoms under control:

Exercise - even though the idea of doing exercise when a patient's joints are stiff and painful may seem odd, exercise is a key part of osteoarthritis treatment. Exercise helps:

• Keep the patient active and mobile
• Build up muscle, resulting in stronger joints
• Relieve mental and emotional stress
• Help achieve body weight control
• Improve posture

All the above-mentioned benefits of exercise help reduce osteoarthritis symptoms.

Patients who have a good doctor or physical therapist should be able to devise an effective and suitable exercise program, which can be done at home or at the local gym. Many gyms today are geared up to help people with arthritis. The patient needs to follow the program carefully, and make sure he/she does not do the wrong exercises or do the exercises incorrectly, which may cause damage.

An exercise plan will probably focus on improving the patient's:

• Flexibility - to help with the range of movement. This will involve gently stretching the joints, making them suppler.
• Strength - to improve muscle tone and strength.
• Fitness - to improve stamina. This may involve swimming, walking or cycling.

Weight control - the more overweight/obese patients are, the worse their osteoarthritis symptoms will be, simply because there is much more weight bearing down on the joints, especially if the affected joints are in the lower limbs.

Losing weight, and maintaining ideal body weight involves eating properly, doing exercise, and sleeping at least 7.5 hours each day. Patients should consult with a doctor, physical therapist or nutritionist before embarking on any exercise program or special diet.

What are the possible complications of osteoarthritis?

• Mobility - some patients may find it hard to move around. There is a greater risk of trips and falls, and their subsequent injuries.
  
  
• Disability - it is not true that osteoarthritis eventually leads to disability. In the majority of cases the condition does cause pain and discomfort, but no permanent disability. In some cases though, it can sometimes eventually leave the patient disabled.
  
  
• Work - some patients may find that osteoarthritis symptoms interfere with their ability to work properly. This can result in frustration, irritability and depression. Patients who experience psychological problems should tell their GP or occupational therapist. Talking to one's employer often helps too.
  
  
• Septic arthritis - this is joint inflammation caused by bacteria infecting the joint. Patients who undergo arthroplasty (joint replacement surgery) run a small risk of infection. Septic arthritis is a medical emergency, and the patient needs to be hospitalized. Treatment involves antibiotic medication and drainage of the infected joint fluid from the joint.

Written by Christian Nordqvist
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today

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