Knee osteoarthritis

Expert reviewer, Mr Damian McClelland, Trauma and Orthopaedic Consultant, and Clinical Director for Musculoskeletal Services at Bupa
Next review due December 2023

Osteoarthritis is a disease that causes pain and stiffness in your joints. Your knee is one of the joints that’s most commonly affected.

An image showing the different parts of the knee

About knee osteoarthritis

If you have osteoarthritis in your knee, the different structures that make up your knee joint become damaged. You lose some of the cartilage that normally allows your bones to move against each other. The shape of your bones can change, and they may develop bony growths, called osteophytes (bone spurs). The membranes that line your knee joint can also become inflamed. These changes affect how well your knee works and can lead to symptoms, such as pain and stiffness.

Osteoarthritis mainly affects people over 50, and you’re more likely to have it the older you are.

Causes of knee osteoarthritis

Doctors don’t know why some people develop osteoarthritis in their knee. But there are some things that can increase your risk. You’re more likely to develop osteoarthritis:

  • as you get older
  • if you’re a woman
  • if you’re very overweight
  • if you have worked in a manual job such as farming, or have always exercised – if you’re a runner, for example

There’s also thought to be a genetic risk, as knee osteoarthritis can run in families.

Osteoarthritis seems to develop after an injury, or a series of minor injuries to your knee joint. It may be that a number of the things above combine to make your knee more susceptible to injury, or to developing osteoarthritis afterwards.

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Symptoms of knee osteoarthritis

Osteoarthritis of the knee usually affects both knees, although you may only notice symptoms in one.

  • You may have knee pain that’s in and around your knee, which becomes worse when you’re active. You won’t usually feel pain in your knee when you’re in bed at night, unless you have severe osteoarthritis.
  • Your knee may be stiff for a while after you’ve been resting or when you first get up in the morning. If you have it in the morning, it will be for less than 30 minutes after you get up.
  • You may find that your knee sometimes gives way, or locks and you can’t straighten it.
  • Because of the pain, stiffness and swelling, you might not be able to move your knee as much or as easily as you would usually.
  • Your knee may creak or grind when you move it – this is called crepitus.

Diagnosis of knee osteoarthritis

Your GP will ask about your symptoms and your medical history and will examine your knee. They’ll usually diagnose knee osteoarthritis from how you describe your symptoms. But they may refer you to have an X-ray and a blood test to help make the diagnosis and to rule out other things.

Self-help for osteoarthritis

There are many things you can do to reduce the pain and stiffness in your knee, and to make living with osteoarthritis a bit easier. Some of the main ones are listed below.

Treatment for knee osteoarthritis

There’s no cure for osteoarthritis but there are things you can do to manage the condition and control your symptoms. The main aim of treatment is to reduce your pain and stiffness, which will improve the way your knees function and restore your quality of life.

Your GP may refer you to various health professionals, which will include a physiotherapist. If you have severe pain and stiffness, your GP may refer you to an orthopaedic surgeon (a doctor who specialises in bone surgery).

Devices and physiotherapy

A physiotherapist will carefully assess your knee and then plan an individual programme of rehabilitation exercises to help strengthen your knee and leg muscles. Make sure you follow these exercises as they may help to keep your knee working well.

Your physiotherapist may suggest giving a transcutaneous electrical nerve stimulation (TENS) machine a try. It’s a device that sends mild electrical currents through your skin to stop or reduce the pain signals coming from your nerve endings. Some people with osteoarthritis find it useful, although it doesn’t work for everyone. You may be able to borrow a TENS machine from your physiotherapist to try, before you decide to buy one.

A physiotherapist can also assess whether knee braces and supports would be useful for you. You can use these as well as other treatments to help keep your knee stable and provide support.

You might also see an occupational therapist – a health professional who can give practical assistance to help you manage with everyday tasks. Your occupational therapist can advise you on changes you can make to your car, home or workplace to ease any stress on your knee. These may include fitting bath aids, chair and bed raisers, grab rails and additional stair rails.


Painkillers can’t cure osteoarthritis but they can help to ease pain and stiffness, and improve your quality of life. Your doctor may recommend them if you’re still in pain after trying self-help measures. Creams and gels are usually the first painkillers that your doctor will suggest. These contain non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or a painkilling substance called capsaicin. You can put these directly onto your knee.

Your doctor may also suggest taking paracetamol if creams and gels aren’t enough. You’ll probably need to take paracetamol regularly, rather than just when you’re in pain.

If these medicines don’t work, your GP may suggest taking NSAID tablets as well as, or instead of, paracetamol, creams and gels. But don’t take NSAID tablets for too long because of the risk of side-effects. Your doctor will usually prescribe another medicine to take alongside NSAID tablets to protect your stomach and reduce the risk of side-effects. Occasionally, if you have severe symptoms and other medicines aren’t helping, your GP may suggest a stronger type of painkiller called an opioid.

If you have a particularly painful, swollen knee joint, your GP may offer you a steroid injection directly into your joint. The injection usually works within a day or so and can last for weeks or months.

Although many people take supplements that contain glucosamine or chondroitin to ease their symptoms, there is limited evidence these work. Ask your doctor if you’d like more advice about these.


If you have osteoarthritis that causes severe pain or has a significant impact on your daily life, your doctor may suggest you have surgery. This will usually only be after you’ve tried the other treatments above, and they haven’t helped.

There are a number of different knee osteoarthritis surgeries, which include the following.

  • Knee arthroscopy. This isn’t usually recommended for most people with osteoarthritis as it doesn’t tend to have much benefit and there are some side-effects involved too. But your surgeon may suggest you have this keyhole surgery to wash out your joint, particularly if your knee has been locking.
  • An osteotomy. In this procedure, your surgeon will cut and refix your bone to avoid putting stress on the damaged part of your knee. This may be an option if you’re under 60.
  • A partial or total knee replacement, in which your surgeon will replace damaged parts of your knee joint with artificial parts.

Your GP will refer you to a surgeon who will discuss your options with you and give you advice on what the best treatment is for you.

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Related information

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    • Osteoarthritis. NICE Clinical Knowledge Summaries., last revised June 2018
    • Osteoarthritis. BMJ Best Practice., last reviewed 27 September 2020
    • Osteoarthritis. PatientPro., last edited 7 March 2017
    • Managing osteoarthritis of the knee. Versus Arthritis., accessed 27 October 2020
    • Electronic pain relief (TENS). Versus Arthritis., accessed 27 October 2020
    • Osteoarthritis: care and management. National Institute for Health and Care Excellence (NICE)., published 12 February 2014
    • Occupational therapist. Versus Arthritis., accessed 27 October 2020
    • Osteoarthritis (OA). Versus Arthritis., accessed 27 October 2020
    • Arthroscopic knee washout, with or without debridement, for the treatment of osteoarthritis. National Institute for Health and Care Excellence (NICE)., published 22 August 2007
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  • Reviewed by Rachael Mayfield-Blake, Freelance Health Editor, December 2020
    Expert reviewer, Mr Damian McClelland, Trauma and Orthopaedic Consultant, and Clinical Director for Musculoskeletal Services at Bupa
    Next review due December 2023