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Osteoarthritis of the Knee

There are lots of different types of arthritis that can affect people. The following information will focus on osteoarthritis, which is the most common type of arthritis.

What is osteoarthritis of the knee? 

Osteoarthritis in general is often misunderstood and as a result there are a lot of mistruths and myths about it.

In simple terms, it is best to consider osteoarthritis as the aging process of your joints. If you look in the mirror, you may find that you do not look like you did when you were 18 years old. You may have a few more wrinkles and a few more grey hairs than back then and these are generally accepted by most people as the outward signs of aging. Your joints undergo an aging process and you are exactly the same age on the inside as you are on the outside, therefore, it isn’t realistic to expect your joints to look like they did when you were 18 either! Perhaps thinking about osteoarthritis as the grey hair and wrinkles of your knees may help you understand it better.


Why have I heard it described as ‘wear and tear’?

As with many other things, sometimes when certain words or phrases are used to describe something, they stick. Unfortunately, the term ‘wear and tear’ is used very regularly to describe osteoarthritis and it is not very helpful. Nothing in your knee is ‘worn’ or ‘torn’, therefore the phrase can be misleading as it suggests that osteoarthritis is damage to the knee.

Does it really matter what you call it?

We really think it does. Words are incredibly important as they help us understand what might be going on in our knee and what we are dealing with. If you have been told that you have osteoarthritis and that it's something you need to be concerned about, then it is only human to find yourself worrying about it. If things are explained correctly and words, phrases and images are used appropriately, you are likely to understand the issue better and be in a better frame of mind to do something about it.



What are the common symptoms of osteoarthritis of the knee?

This is a really important question and it is useful for you to know what is normal for a knee that may have osteoarthritis. We’ve broken the answer down into things that are found most commonly:

How is osteoarthritis diagnosed?

In most cases, osteoarthritis can be suspected or diagnosed through the clinical features (what it looks like and how it behaves), your symptoms (what you tell us about your knee) and the clinical assessment (testing the movements etc.). An X-ray of the knee is often used to help diagnose osteoarthritis but is not always required.

Why are X-rays/scans not always required?

In a lot of cases, the information we as healthcare professionals can get from asking you questions and testing the knee is enough to make a decision. X-rays are a very useful tool as they show you what your knee looks like on the inside. however, in some cases what your knee looks like on the inside doesn’t really marry up with what your problem might be.

There is growing evidence (experiments and clinical studies) that demonstrate what you see is not always what you get with X-rays and scans, and that a lot of the so-called ‘worn out’ or ‘abnormal’ findings are seen commonly in people with no pain, stiffness or symptoms.

In a large study of over 700 people, Geurmazi et al. (2012) demonstrated that most of the common ‘problems’ found in knee scans/imaging are seen as much, and sometimes more, in people WITHOUT any pain, stiffness or symptoms as those with symptoms.


What causes osteoarthritis of the knee?

This is a difficult question and the simplest answer is that it is complicated. As we’ve explained in the last question, what you see is not always what you get, and just because an X-ray says you’ve got osteoarthritis of the knee, doesn’t mean you’ll actually have any problems.

There are many factors that will influence the development of osteoarthritis including increased weight, low activity levels, previous injury, diet, genetics and negative beliefs. It is unlikely that just one of these factors will cause osteoarthritis, however, they may influence whether a person experiences symptoms or not.

What can I do to help myself?

Reassuringly, there are lots of things that you can do to help get your knee going and start your rehabilitation.

The following points have been written from the NICE guidelines (2014) – Osteoarthritis: care and management.

Will it get better?

In a lot of cases, it is very much possible for you to improve the symptoms you have with your knee. Obviously, you cannot turn back the clock and the osteoarthritis will still be there even if you feel better but by being stronger, fitter, more confident and closer to your ideal bodyweight, you can start to regain some more control over your knee.


How long will it take before I feel something?

This is a very difficult question, but it is best to think about how much time and effort you are going to throw at the challenge and how confident and motivated you are to do something about it. If you work hard and are consistent with what you do, often people will notice signs of positive response within weeks to months. If you are not committed to the challenge it will take longer or may not respond at all.

Frequently asked questions

Below are some of the common questions that are asked when talking about knee issues that haven’t been covered in the information above.


A: This doesn’t matter. Most, if not all, of the exercises below can be modified or adapted using heavy bags, bottles of water or even books. 

A: Yes. As mentioned above, exercise is the best medicine for most things, including sore knees. Think of your knee as being strong and robust but irritated. Starting exercise might cause a bit of irritation but it will not damage your knee. It is safe to be sore.

A: Good question. For strengthening, it doesn’t matter too much as long as you work until your muscles can’t give you anymore. In other words, you exercise until your muscles start to tire. It is worth noting that your muscles will get sore as they tire, but this is okay and it often means you are pushing things as hard as you should.

As a rough guide, we often recommend 8 to 12 repetitions completed 3 to 4 times (i.e. in 3-4 sets). You should complete these sets together (i.e. within a 15-20 minute time frame) rather than spread throughout the day. Try to do this on 3 to 4 days over the week.

A: Rest is not evil and can be very useful if you’ve ‘overdone’ it, but rest doesn’t change you for the better and rest will not change your knee for the better.

A: Firstly, ask yourself if you’ve really done everything you can to try and move your knee issue forwards. If the answer is no, consider re-reading the information above and seeking some guidance from your physio.

If you really have worked hard at the above advice and guidance, then some people do find benefit from steroid injections into the knee joint, but it is worthwhile remembering that steroids are drugs and there is always the possibility of side effects and it not working. Injections should not be used to manage your knee pain long-term. You can discuss this option with your GP.

If you still don’t find any benefit from your injection, then you may be referred to the hospital to have a discussion with the Bone and Joint teams about your options.


Guermazi A,   Niu J, Hayashi D,   Roemer FW ,  Englund M,  Neogi T, Aliabadi P,  McLennan CE & Felson DT. (2012). Prevalence of abnormalities in knees detected by MRI in adults without knee osteoarthritis: population based observational study (Framingham Osteoarthritis Study. BMJ 2012 Aug 29;345:e5339.doi: 10.1136/bmj.e5339.

Bricca A, Roos EM,  Juhl CB, Skou ST, Silva DO, Christian J & Barton CJ. (2019) Infographic. Therapeutic exercise relieves pain and does not harm knee cartilage nor trigger inflammation. BJSM. DOI: 10.1136/bjsports-2019-100727


National Institute for Health Care Excellence (2014). Osteoarthritis: care and management (NICE guideline 177). Available at: (accessed 27/10/2020).

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