What is osteoarthritis?

Osteoarthritis is a very common condition which can affect any joint in the body. It’s most likely to affect the joints that bear most of our weight, such as the knees and feet. Joints that we use a lot in everyday life, such as the joints of the hand, are also commonly affected.

In a healthy joint, a coating of tough but smooth and slippery tissue, called cartilage, covers the surface of the bones and helps the bones to move freely against each other. When a joint develops osteoarthritis, part of the cartilage thins and the surface becomes rougher. This means the joint doesn’t move as smoothly as it should.

When cartilage becomes worn or damaged, all the tissues within the joint become more active than normal as the body tries to repair the damage. The repair processes may change the structure of the joint, but will often allow the joint to work normally and without any pain and stiffness. Almost all of us will develop osteoarthritis in some of our joints as we get older, though we may not even be aware of it.

However, the repair processes don’t always work so well and changes to the joint structure can sometimes cause or contribute to symptoms such as pain, swelling or difficulty in moving the joint normally.

For example:

  • Extra bone may form at the edge of the joint. These bony growths are called osteophytes and can sometimes restrict movement or rub against other tissues. In some joints, especially the finger joints, these may be visible as firm, knobbly swellings.
  • The lining of the joint capsule (called the synovium) may thicken and produce more fluid than normal, causing the joint to swell.
  • Tissues that surround the joint and help to support it may stretch so that after a time the joint becomes less stable.

Symptoms

The main symptoms of osteoarthritis are pain and sometimes stiffness in the affected joints. The pain tends to be worse when you move the joint or at the end of the day. Your joints may feel stiff after rest, but this usually wears off fairly quickly once you get moving. Symptoms may vary for no obvious reason. Or you may find that your symptoms vary depending on what you’re doing.

The affected joint may sometimes be swollen. The swelling may be:

  • hard and knobbly, especially in the finger joints, caused by the growth of extra bone
  • soft, caused by thickening of the joint lining and extra fluid inside the joint capsule.

The joint may not move as freely or as far as normal, and it may make grating or crackling sounds as you move it. This is called crepitus.

Sometimes the muscles around the joint may look thin or wasted. The joint may give way at times because your muscles have weakened or because the joint structure has become less stable.

Causes

It’s still not clear exactly what causes osteoarthritis. We do know it isn’t simply ‘wear and tear’ and that your risk of developing osteoarthritis depends on a number of factors:

Age

Osteoarthritis usually starts from the late 40s onwards. This may be due to bodily changes that come with ageing, such as weakening muscles, weight gain, and the body becoming less able to heal itself effectively.

Gender

For most joints, osteoarthritis is more common and more severe in women.

Obesity

Being overweight is an important factor in causing osteoarthritis, especially in weight-bearing joints such as the knee and the hip.

Joint injury

A major injury or operation on a joint may lead to osteoarthritis in that joint later in life. Normal activity and exercise don’t cause osteoarthritis, but very hard, repetitive activity or physically demanding jobs can increase your risk.

Joint abnormalities

If you were born with abnormalities or developed them in childhood, it can lead to earlier and more severe osteoarthritis than usual.

Genetic factors

The genes we inherit can affect the likelihood of getting osteoarthritis at the hand, knee or hip. Some very rare forms of osteoarthritis are linked to mutations of single genes that affect a protein called collagen. This can cause osteoarthritis to develop in many joints at an earlier age than usual.

Other types of joint disease

Sometimes osteoarthritis is a result of damage from a different kind of joint disease, such as rheumatoid arthritis or gout.

Two factors that may affect the symptoms of osteoarthritis, but aren’t a direct cause of it are the weather and diet:

Weather

Many people with osteoarthritis find that changes in the weather make the pain worse, especially when the atmospheric pressure is falling – for example, just before it rains. Although the weather may affect the symptoms of your arthritis, it doesn’t cause it.

Diet

Some people find that certain foods seem to increase or lessen their pain and other symptoms. However, your weight is more likely than any other specific dietary factors to affect your risk of developing osteoarthritis.

Surgery

Most people with osteoarthritis won’t need surgery, and it’s usually only considered once you’ve tried all other suitable treatments.

The options include:

  • joint replacement surgery
  • keyhole surgery techniques to wash out loose fragments of bone and other tissue from your knee – this is called arthroscopic lavage and is normally only available privately in the UK
  • joint fusion – where the bones in a joint are fixed together surgically – this prevents movement of the joint, and therefore pain.

If you’re thinking of having surgery, take some time to find out what you can expect from it, what the possible risks are, and how you can best prepare for your operation and plan ahead for your recovery.

How will osteoarthritis affect me?

Osteoarthritis affects different people, and different joints, in different ways. But, for most people, osteoarthritis doesn’t continue to get steadily worse over time.

For some people, the condition reaches a peak a few years after the symptoms start and then remains the same or may even improve. Others may find they have several phases of moderate joint pain with improvements in between.

The degree of damage to a joint isn’t very helpful in predicting how much pain you’ll have. Some people have a lot of pain and mobility problems from a small amount of damage, while others have a lot of damage to the joint but few or no symptoms.

If you have severe osteoarthritis, you may find some of your daily activities more difficult depending on which joints are affected. More severe osteoarthritis can also make it difficult to sleep.

Which joints are affected?

Any joint can develop osteoarthritis, but symptoms linked to osteoarthritis most often affect the knees, hips, hands, spine and big toes.

The knee

Osteoarthritis of the knee is very common. This is probably because your knee has to take extreme stresses, twists and turns as well as bearing your body weight. Osteoarthritis often affects both knees.

Diagnosis

It’s important to get an accurate diagnosis if you think you have arthritis, as different types of arthritis often need very different treatments. The diagnosis of osteoarthritis is usually based on:

  • your symptoms – how and when they started, how they’ve developed, how they affect your life, and any factors that make them better or worse
  • a physical examination – your doctor will check for:
    • tenderness over the joint
    • creaking or grating of the joint – known as crepitus
    • bony swelling
    • excess fluid
    • restricted movement
    • joint instability
    • weakness or thinning of the muscles that support the joint.

What tests are there for osteoarthritis?

There’s no blood test for osteoarthritis, although your doctor may suggest you have them to help rule out other types of arthritis.

X-rays aren’t usually helpful in diagnosing osteoarthritis, although they may be useful to show whether there are any calcium deposits in the joint.

In rare cases, an MRI scan of the knee can be helpful to identify other possible joint or bone problems that could be causing your symptoms.

Should I see a specialist?

It’s unlikely that you’ll need to see a specialist to get a diagnosis of osteoarthritis, although your doctor may refer you if there’s some doubt about the diagnosis or if they think there might be additional problems.

Your doctor may refer you if specialist help is needed to manage your osteoarthritis – this might be for physiotherapy, podiatry for foot problems, or occupational therapy, which can help if you’re having difficulty with everyday activities.

If your arthritis becomes severe and is causing long-term problems, your GP may refer you to an orthopaedic surgeon to consider joint surgery or to a pain management programme.

Managing your symptoms

 Although there’s no cure for osteoarthritis yet, there are treatments that can provide relief from the symptoms and allow you to get on with your life. These include:

  • lifestyle changes
  • pain relief medications
  • physical therapies
  • supplements and complementary treatments.

Physical activity

Many people worry that exercising will increase their pain and may cause further joint damage. However, while resting painful joints may make them feel more comfortable at first, too much rest can increase stiffness.

You shouldn’t be afraid to use your joints. If pain makes it difficult to get started with exercise, you could try taking a painkiller such as paracetamol beforehand. And if you feel you’ve overdone things a bit, try applying warmth to the painful joint – or if it’s swollen, applying an ice pack may help.

If you haven’t done much exercise for a while you might want to get advice from a physiotherapist. They’ll be able to help you work out a programme that works for you. The most important thing is to start gently and build up gradually.

There are three types of exercise you should try to include:

Range of movement exercises

These exercises involve taking joints through a range of movement that feels comfortable and then smoothly and gently easing them just a little bit further.

Strengthening exercises

These are exercises performed against some form of resistance to strengthen the muscles that move and support your joints. You could use light weights, a resistance band or try exercising in water.

Aerobic exercise

This means any physical activity that raises your heart rate and gets you breathing more heavily. This type of exercise burns off calories, so it can help if you need to lose a bit of weight. It can also improve your sleep and help to reduce pain.

Walking, cycling and swimming are all excellent forms of exercise for people with arthritis. Or you could try an exercise bike or cross-trainer. Walking laps in the shallow end of a swimming pool is also great for strengthening leg muscles.

Hydrotherapy or aquatic therapy pools are warmer than normal swimming pools. The warmth is soothing and relieves pain and stiffness, while the water supports your weight but still offers some resistance for muscle-strengthening exercises.

Tips for managing pain

Warmth and cold

Applying a hot-water bottle, wrapped in a towel to protect your skin, or a wheat-bag that you heat up in a microwave can help to ease pain. An ice pack, again wrapped in a towel to protect your skin, often helps to reduce swelling and discomfort. Ice can be applied for up to 20 minutes every couple of hours.

Living with osteoarthritis

Osteoarthritis can affect many different areas of your life, but there are things you can do to help reduce any problems it’s causing.

Managing at home

Depending on which joints are affected, there are lots of aids and adaptations to help you around the home, and some fairly simple changes can make a big difference.

If you’re not sure what’s available or how you might be able to reduce the strain on your joints, an occupational therapist will be able to advise you.

You may be able to get help with the costs of obtaining aids or having adaptations to your home. Eligibility varies depending on whether you live in England, Wales, Scotland or Northern Ireland. Wherever you live, the first step is to ask your local authority for a needs assessment.

Possible complications

The changes in cartilage that occur with osteoarthritis can encourage crystals to form within the joint. These may be:

  • sodium urate crystals, which can cause attacks of gout. The big toe is the most commonly affected joint.
  • calcium pyrophosphate (CPP) crystals, which can also cause sudden severe pain and swelling. CPP crystals can affect any joint but are more common in joints already affected by osteoarthritis.

Research and new developments

Research is helping us to understand more about the causes of osteoarthritis, and to develop new treatments.

Our previous research has:

  • highlighted the important role that exercise can play in reducing pain
  • contributed to the approval for NHS funding of a treatment called autologous chondrocyte implantation (ACI) that repairs small areas of damaged cartilage using healthy cartilage grown from your own cells
  • identified a number of jobs linked with a higher risk of developing osteoarthritis.

Research we’re currently funding includes:

  • a centre based in Oxford , which is looking at how osteoarthritis develops and aims to find new ways of predicting how it’s likely to progress
  • a pain centre, based in Nottingham, which aims to improve our understanding of what causes pain so that better treatments can be developed
  • early trials of stem cell treatments, which could help to repair cartilage damaged by osteoarthritis
  • a study into the part played by nerve proteins in and around the joints to find out if they could be a target for future pain treatments.

Exercises for osteoarthritis

Straight-leg raise (sitting)

Sit well back in a chair, with your back straight, shoulders back and head level.

Straighten and raise one leg. Hold for a slow count to 10, then slowly lower your leg. Repeat this at least 10 times for each leg.

As the exercise becomes easier, try it with light ankle weights and pull your toes towards you, so you feel a stretch at the back of your lower leg.

Straight-leg raise (lying)

You can do this on the floor or lying in bed. Bend one leg at the knee. Hold your other leg straight and lift your foot just off the floor or bed. Hold for a slow count of five, then lower. Repeat five times with each leg every morning and evening.

Muscle stretch

Do this at least once a day when lying down. Place a rolled-up towel under the ankle of one leg and bend the other leg at the knee. Use the muscles of your straight leg to push the back of the knee towards the bed or the floor. Hold for a slow count of five. Repeat at least five times with each leg.

Quad exercise

Lie flat on the floor or a bed, keeping your legs straight. Pull your toes towards you, while pressing your knee towards the floor or bed. Hold for five seconds and relax. Repeat five times.

Hip abduction

Stand with one hand resting on the back of a chair or a work surface for support.

Lift your leg straight up to the side. Hold for five seconds and then slowly lower your leg. Try to keep your body straight throughout. Repeat five times on each side.

Arm stretch (standing)

Stand with your arms relaxed at your sides. Raise your arms as far as you can and hold for 5–10 seconds. Lower and repeat five times.

You can do this exercise by raising your arms either in front of you or to the side. Doing some of each will stretch more muscles.

Arm stretch (lying)

Lie on your back with your arms by your sides. Raise your arms overhead as far as you can and hold for 5–10 seconds. Return your arms to your sides and repeat five times.

Arm lifts

Place your hands behind your head so your elbows are pointing to the sides and pressed back as far as you can. Hold for five seconds.

Then place your hands behind your back, again keeping your elbows pointing out and pressed back as far as you can. Hold for five seconds. Do five sets.