Knee arthritis

What is it?

Knee arthritis is inflammation of your knee joint. There are many types of arthritis; the most common type is osteoarthritis.

The ends of your shin bone and thigh bone in your knee joint are covered in articular cartilage. This type of cartilage allows the ends of your bones to move against each other smoothly. If you have osteoarthritis, your articular cartilage gradually roughens and becomes thinner.

Symptoms

Your knee will be stiff and painful, and may be swollen. The pain may be worse after you have been exercising.

You may not be able to move your knee as much or as easily as you would normally. Your knee may creak or grind when you move it – this is called crepitus.

 

Causes

The exact reasons why osteoarthritis develops aren't fully understood. We know that the risk of getting osteoarthritis increases as you get older. It's also thought to run in families.

Exercise doesn't usually lead to osteoarthritis, unless you're doing excessive amounts of exercise. However, injuries to your knee joint an lead to osteoarthritis later in life. A common cause of knee osteoarthritis is a tear in your meniscal cartilage (the tissue that acts as a shock absorber in the knee joint) or a tear in the ligaments in your knee after a twisting injury.

Treatments

Pain killers, such paracetamol and ibuprofen, will help to reduce pain and swelling. You can also rub anti inflammatory creams into your knee to reduce the pain and stiffness.

An injection of steroids into your knee joint or a tender spot around your knee can sometimes be helpful.

Glucosamine and chondroitin supplements may provide you with some pain relief, although there is only limited evidence that they are effective. These chemicals are found naturally in cartilage and it's thought that taking supplements may improve damaged cartilage. Glucosamine comes from shellfish so don't take it if you have a shellfish allergy.

Your doctor may refer you to a physiotherapist, who will show you some exercises you can do to help reduce the pain.

Do

• Eat a healthy balanced diet and try to keep your weight as close to the ideal for your height and age as possible. If you're overweight, it's more likely that your osteoarthritis will get worse.
• Exercise your thigh muscles (quadriceps), as they become weaker if you have knee osteoarthritis. Strengthening these muscles will improve your movement and reduce the pain.
• Wear well-cushioned shoes or trainers to act as a shock absorber.
• Rest your knee if it becomes painful.

Don't

• Put your knee under too much strain.
• Keep your leg in the same bent position for long periods of time.

Peer reviewed by Simon Fairthorne, MCSP, Bupa Sports Medicine physiotherapist

Publication date: June 2009