Osteoarthritis

Osteoarthritis is the most common type of arthritis in the UK which is also known as ‘wear and tear’ arthritis or ‘degenerative joint disease’. It manifests itself as damage to the surface of the joints.

More than 8 million people in the UK have osteoarthritis. This includes osteoarthritis of the spine and the knees which are the parts of the body most commonly affected.

(Source: NHS Choices/arthritis)

But osteoarthritis can also develop in the spine, hips, hands, feet, neck and shoulder.

Osteoarthritis is discussed in the following manner in this section of the guide:

• How does osteoarthritis occur?
• Why is osteoarthritis painful?
• Causes of osteoarthritis
• Symptoms of osteoarthritis
• Osteoarthritis progression
• Diagnosis of osteoarthritis
• Treatment for osteoarthritis
• Managing osteoarthritis

How does osteoarthritis occur?

Let’s start with a brief look at the anatomy of a joint typically affected by osteoarthritis, e.g. the knee joint. A joint is defined as the point where two bones meet.

There is a thin spongy layer of connective tissue in the joints called cartilage. This cartilage is located at the point where these two bones meet and acts as a cushion. It protects the joint against any external forces and also acts as a balancing mechanism when weight is put on the joint.

For example, when a person runs or squats down.

This cartilage has a slippery texture which enables the bones to move smoothly and easily. There is an additional layer of cartilage called the ‘meniscus’ – a disc shaped layer of gristle which acts a shock absorber.

Ligaments around the knee provide extra support. This joint is surrounded by a capsule and within lies a thin membrane called the ‘synovium’.This membrane produces ‘synovial fluid’ which helps to nourish and lubricate the joint.

This is all well and good.

But what happens is that this cartilage wears down over time which decreases the protection to the joints. It also develops a rough texture. The bones of the joint become thicker and develop a bony outgrowth or ‘spur’ which may be the body’s way of repairing this damaged cartilage.

The synovium swells and produces extra fluid which causes a swelling in the joint. Inflammation also occurs.

The muscles and tendons weaken and lose their elasticity.

This process takes place over a long period of time.

Why is osteoarthritis painful

This is caused by friction between the two bones which rub against each other causing pain and discomfort. This occurs in severe cases of osteoarthritis where the cartilage has degraded to such an extent that it no longer provides any cover for these bones.

As these bones rub together they cause each other to wear away and can eventually, distort the shape of the joint. The bones are pushed out of their normal alignment which leads to problems with mobility.

This is why in some cases osteoarthritis can be intensely painful.

Most people only experience minor alterations to their joints but a few are unlucky enough to have the full blown symptoms which are also progressive.

Causes of osteoarthritis

There are several causes of this form of arthritis which include:

• Age
• Injury, e.g. sports injury
• Gender
• Obesity
• Genetics
• Abnormality in the joints

Age

Age is a classic cause of osteoarthritis. The main reason for this is a weakening of the joints over time due to wear and tear. Like any part of the body, they are susceptible to damage and are less effective at dealing with this as we age.

Injury

Severe or repeated injuries to the joints, e.g. a torn cartilage can cause permanent damage which also leaves them open to conditions such as osteoarthritis. This is often the case following intense exercise or heavy, physically demanding jobs.

Gender

More women than develop osteoarthritis especially osteoarthritis in the knees although men tend to develop this in the hips. There are various theories as to why women are more susceptible to this condition which are based upon the hormone oestrogen. Another reason is the structure of the female skeleton, in particular the acute angle between the pelvis and the knees which leaves women more prone to health problems.

Obesity

Obesity causes a whole range of problems such as osteoarthritis of the knee which is due to an excessive load on the knees caused by this extra weight.

Genetics

Genetics appears to play a part. There is evidence to suggest that osteoarthritis may run in families, for example ‘nodal osteoarthritis’:this is a form of arthritis which affects the hands. Another possibility is the effect of genes on collagen production which is an essential component of cartilage.

Abnormality

An abnormality or some other form of trauma to the joints causes damage which then predisposes that joint to diseases such as osteoarthritis. It’s as if this damage leaves the joint in a vulnerable and weakened condition which is open to developing arthritis.

Symptoms of arthritis

The main symptoms include sore, painful joints which stiffen after exercise or towards the end of the day. This pain and stiffness often wears off once you start moving again but it can be prolonged in more serious cases.

The joint appears to ‘crunch’, creak or grind during movement which is also known as ‘crepitus’. In some cases the muscles and tendons around the joint have become weakened which causes the joint to become unsteady and give way on occasion.

The joint may look swollen and misshapen.

These symptoms appear to worsen after physical exercise or during changes in the weather, for example during a cold and wet spell.

Osteoarthritis progression

The progression of this condition varies according to the individual. Some people experience a mild flare up followed by a long period of inactivity. But others are unfortunate enough to experience a worsening of their symptoms which can result in a disability.

Diagnosis of osteoarthritis

Your GP will make a diagnosis following a physical examination of your joints and a discussion of your symptoms. He/she will look for the following indicators of osteoarthritis which include:

• Excess synovial fluid around the joint
• Pain
• Stiffness especially after movement
• Restricted movements
• Joint is sore to the touch and has an enlarged appearance
• Creaking or crunching sound in the joint
• Unsteadiness of the joint

A blood test will be performed as part of the diagnosis plus additional tests such as an X-ray and/or MRI scan.

Treatment for osteoarthritis

There is presently no cure for osteoarthritis but there are ways of managing this condition which include diet and exercise, physiotherapy, mobility aids such as a walking stick and medication.

Joint replacement surgery may be needed in severe cases.

Find out more about this and other forms of treatment in our treatment for arthritis section.

Managing osteoarthritis

There is plenty of help and information available which is designed to help you control your arthritis and live a normal life. This includes pain relief, changing your job, finding out what benefits you are entitled to and counselling.

For more information about these visit our living with arthritis section.