Knee osteoarthritis (OA) is a medical diagnosis that describes pain and stiffness of the knee joint caused by degeneration of joint cartilage.
The pain is actually caused by the aggravation of worn cartilage, not by the wear-and-tear itself. So the pain can improve and go away, even if the cartilage degeneration doesn’t change!
That’s an important distinction to make – too often, signs of knee osteoarthritis on X-ray are treated like the start of a steady decline into chronic pain and dysfunction.
In reality, knee osteoarthritis is very common and very treatable with a few simple steps. It may flare up from time to time, but the outlook is very good in a majority of cases.
Knee osteoarthritis (often referred to as “knee OA”) is the most common form of arthritis but it’s still the subject of many myths and dramatizations. As a Physiotherapist, I can help clear that up – here are the answers to the most common questions on knee arthritis.
What does osteoarthritis in the knee feel like?
Knee osteoarthritis is characterised by a number of symptoms – it’s a deep ache that’s often hard to localise to a specific area of the knee, as well as pain and stiffness after inactivity (like when you first wake up).
Another feature of osteoarthritis is knee swelling, although that’s not always present or visible in every case of knee OA.
Knee osteoarthritis typically comes on gradually, with patients describing pain with or without swelling the day AFTER they’ve “overdone it in the garden”.
Episodes of knee OA, commonly referred to as flare ups, can last from a few days to a few months – timeframes will be shorter with milder aggravations and with less risk factors (discussed in the section on “How quickly does osteoarthritis spread?” below).
How do I know if I have knee osteoarthritis?
Knee osteoarthritis can be diagnosed in a number of different ways – on examination by a health professional and/or with medical imaging.
A clinical diagnosis (ie. during a visit to a doctor or Physiotherapist) can be made based on the history and features of the knee pain.
This will typically include several episodes over a number of years, the presence of pain on palpation around the knee joint line, chronic or recurrent swelling and aged 45-50 years or older.
An imaging diagnosis can be made via X-ray, CT scan or MRI. On these scans, they look for how many of the 4 signs of knee osteoarthritis are present to confirm the presence and severity of the knee OA.
One point to note with imaging diagnosis – the appearance of the knee osteoarthritis on imaging DOES NOT directly correlate to the symptoms!
That means that a nasty looking knee OA on imaging may not cause nasty symptoms. So don’t panic if the scan looks worse than expected.
How can I tell if my knee pain is arthritis?
Firstly, osteoarthritis is definitely present in anyone over the age of 50 – your cartilage wasn’t made to last forever so some wear is inevitable. But that doesn’t mean that it’s going to cause pain and swelling.
Degenerated cartilage will only cause pain is specific circumstances and loading patterns, so you can’t assume that every knee pain is knee osteoarthritis.
If you’re over the age of 50 years, have already been diagnosed with knee OA and you have knee pain and swelling that comes on gradually, it’s safe to say that this is probably an episode of knee osteoarthritis.
For anyone younger that 50 years or that hasn’t been diagnosed with knee OA, there are many other causes of knee pain. Without a confirmed diagnosis, I wouldn’t assume your pain is due to knee osteoarthritis.
Which part of the knee is affected in osteoarthritis?
The knee joint is made up of three separate joint surfaces and any or all of them may be affected by knee osteoarthritis.
There’s the Medial Tibiofemoral joint – the contact between the thigh bone and shin bone on the side closest to the other knee.
The Lateral Tibiofemoral joint – this is joint surfaces between thigh and shin bone on the side away from the other knee.
Then there’s the Patellofemoral joint – this is the relatively small joint surface between the kneecap and the thigh bone.
What are the signs of needing a knee replacement?
This is probably one of the biggest myths about knee osteoarthritis – anyone with OA will need a joint replacement.
It’s sometimes heard is the sales pitch of a knee surgeon, and it’s technically not wrong….BUT it’s very misleading.
If we all lived to 200 years old, we’d all need knee replacements as our cartilage can’t last forever.
But the reality is that for most of us, our knee cartilage will last our lifetime without the requirement for a knee replacement.
Knee OA is not a steady consistent decline – once the pain starts, you’re NOT destined to have a lifetime of knee pain and misery. Although the cartilage degeneration is not reversible, the pain and stiffness are almost always reversible.
Can anything be done for osteoarthritis of the knee?
The short, and research supported, answer is a resounding YES!
There’s a long list of treatments and positive lifestyle changes that can make all the difference for knee OA.
Regular exercise, strength training, weight loss and anti-inflammatory medication are all proven to have a great impact on episodes of knee osteoarthritis.
But they’re not referred to as “fixes” or “cures” for knee OA as osteoarthritis is always a work in progress.
You can’t start regular exercise until the pain goes away, then just stop and expect it to have lasting effects.
It’s why we refer to many of the treatments for knee OA as “lifestyle changes” – they need to be ongoing to successfully manage the issue.
Is walking good for osteoarthritis of the knee?
Walking is great for knee osteoarthritis! It’s gentle, can be modified easily for days with more pain (eg. shorter walks) and combines movement with weight-bearing load to get the best results.
The weight-bearing aspect of walking is necessary to maintain healthy cartilage as well as help resolve any swelling inside the knee.
It’s worth noting that running isn’t a bad idea either, provided that you were a runner before you were diagnosed with knee OA (ie. it’s very risky to take up running for the first time after the age of 50 years).
Running has been shown to NOT cause knee OA – in fact it can actually improve joint quality and maintain strength.
You just need to ease back into it slowly after an OA flare up by starting with a run:walk approach and only after you’ve started your strength training.
What is the most effective treatment for knee arthritis?
Strength training is the most effective long term management strategy for both prevention and resolution of episodes of pain and stiffness.
Exercises should focus on leg strength generally as well as task-specific strength for common activities that you perform each day.
Anti-inflammatory medication can also be very helpful but should only be taken under the guidance of your health professional.
It’s one of the most effective ways to reduce knee swelling as it limits the addition of new fluid into the knee joint.
Compressive knee braces can be helpful to manage swelling as well as improving control of the knee, both of which will reduce pain.
A simple knee brace made of a firm elastic material is all that’s required, such as this one.
Just note that you should measure up your unaffected knee for sizing, as buying one to fit your swollen knee today might not fit well as the knee reduces in size.
Note that fancy braces with hinges or metal struts don’t assist knee movement for OA and should be avoided.
Ice packs can also be helpful in reducing pain so you can exercise. But contrary to popular belief, ice packs don’t improve swelling!
What happens if osteoarthritis is left untreated?
Untreated knee osteoarthritis tends to follow a pattern of slowly worsening episodes.
Each episode is self-limiting to a certain extent – you overdo it and cause knee pain -> the knee pain forces you to rest -> the rest allows the knee to settle and the pain goes away.
But, and it’s a big BUT, you’re now weaker and your cartilage is less resilient to loading, so the next episode happens with less provocation and takes longer to recover from.
And so the cycle continues, until you break the cycle with any or all of the treatment approaches listed above.
Does walking worsen osteoarthritis?
Consistent and regular exercise is needed to maintain joint movement and cartilage quality.
The big focus is on consistency – a small walk every day is preferable to 1-2 big walks each week.
The body thrives on adapting to your activity levels. If those levels are inconsistent and sporadic, the body never quite adapts.
To answer the question, walking is great for knee osteoarthritis but only if it’s consistent (every day or two is ideal).
What is the latest treatment for osteoarthritis?
Treatments for knee osteoarthritis need to focus on the cause of pain and degeneration.
Most of the pain associated with knee OA comes from the swelling that builds up inside the knee.
That fluid pressure causes a loss of joint range and puts pushes into the soft bone underneath the areas of patchy or thinned cartilage.
That pressure into the cartilage injury causes the break down to accelerate and the condition to worsen.
So the latest treatment for knee osteoarthritis is focused on minimising irritation and swelling.
Strength exercises provide control of movement to minimise irritaion.
Medication can manage the amount of swelling being produced inside the knee to reduce the fluid pressure.
Regular walking can help remove swelling from inside the knee and improve the quality of the existing cartilage.
What are the 4 worst foods to eat if you have arthritis?
plenty too many internet articles on good foods and bad foods for knee osteoarthritis.
It can get confusing and make dietary control nearly impossible.
So here’s a simplified version of the 4 worst foods or food ideas for knee OA:
- Too much food – controlling your portions will have the biggest impact on weight management
- Processed sugars – processed sugars aren’t evil and you’ll never completely cut them out but they do contribute to inflammation
- Alcohol – it directly contributes to inflammatory process so any reaction inside the knee is heightened/worsened
- Inadequate protein – without realising it, we often lack sufficient protein for your body to build muscle and healthy joints
How serious is osteoarthritis of the knee?
Knee osteoarthritis needs to be kept in context – yes, it causes pain and can temporarily limit your activity levels.
But it happens to everyone and it’s very manageable with the right long term approaches.
Knee OA can become difficult to manage and have other health consequences only if it’s allowed to worsen without being addressed.
The simple message is address it as early as possible and make positive lifestyle changes – don’t search for quick fixes that ignore the underlying cause.
Will osteoarthritis cripple me?
You will occasionally get nasty episodes of knee osteoarthritis that can cause severe limitations to your function – just remember that these are temporary and can be remedied with the right approaches.
Avoid being reactionary with your management of knee OA – don’t wait for it to swell to start meds and don’t wait for the pain to start your strength exercises.
Strength work needs to become part of your daily routine. And think about using medication as soon as you think you’ve overdone it rather than waiting for the swelling to build up.
What is end stage osteoarthritis of the knee?
The end stage of osteoarthritis tends to have severe pain, significant swelling and, as a result, significant loss of function.
It is the end result of decades of worsening episodes and shouldn’t be confused with a severe episode due to a period of out-of-the-ordinary activity.
For example, if you have knee OA and you run up Mt Everest, it’s going to flare up big time. You’ll have severe pain, lots of swelling and won’t be able to walk.
Despite those symptoms matching the description of end stage knee osteoarthritis, it’s not end stage knee OA – it’s a massive flare up of early to mid stage OA.
The message here is that it’s the pattern of episodes and decades of time that make severe pain = end stage knee OA. Without a pattern of declining function and worsening pain for years and years, it may be a severe episode rather than end stage OA.
How quickly does osteoarthritis spread?
Knee osteoarthritis will spread and worsen based on how many risk factors you have for OA.
Risk factors for knee OA include excessive body weight, previous damage/trauma (such as ACL rupture), inconsistent levels of exercise (such as only running once per week) and chronic hip or ankle stiffness.
Note that distance running and sports with repetitive joint loading do not cause knee OA – it’s the inconsistent nature of only training once per week, or training for 2 weeks then having two weeks off, that cause knee OA.
What are the 4 stages of osteoarthritis?
Knee osteoarthritis is classified from grade 1 to 4 depending on the number of features of OA present on imaging and the depth of the cartilage loss.
The 4 signs of knee osteoarthritis on imaging are:
- Loss of joint space (distance between the two bones that make up the joint)
- Bony spurs around the joint (referred to as “osteophytes”)
- Subchondral pitting (small pits in the bone under the cartilage caused by fluid pressure)
- Subchondral sclerosis (breakdown of bone under the joint cartilage)
The grading of knee osteoarthritis is simply a tally of the number of the four signs present on the x-ray. If you have loss of joint space and bone spurs, you have Grade 2 knee osteoarthritis.
Is grade 4 osteoarthritis serious?
Grade 4 knee osteoarthritis would be defined as having all four features of knee OA on an x-ray.
Those features are indicators of knee OA changes but don’t actually tell us how severe the condition or the pain will be.
That’s because there’s very little correlation between the appearance of your x-ray and your symptoms.
You can have a knee that’s showing all four signs of OA on imaging, but it’s actually not painful and functions perfectly well.
So grade 4 knee OA isn’t serious in itself and should be managed based on how it feels, not how it looks.
What is considered severe osteoarthritis?
Severe knee osteoarthritis is defined as having significant ongoing pain, rapidly worsening pain and/or significant disability.
This is a knee that stops you from doing basic daily tasks and is becoming unmanageable, when the usual medication and exercises no longer have an effect.
It’s at this point that a knee replacement might be considered, depending on a number of other factors.
Although the process of knee OA is limited to the knee, it can begin to affect your general health (including heart health) if it stops you from being active.