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Knee arthritis does not mean a knee replacement
Most people who come to us with a painful knee are carrying the same worry - that arthritis leads to surgery, and surgery means a new knee. For most people, it does not.
Osteoarthritis moves through four stages. It is usually only at the fourth that a knee replacement becomes the conversation. Most people who walk into our clinic are not there - and many of them never get there.
Where a replacement actually sits
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A knee does not go from sore to replaced. There is a long road in between, and nearly everything we do happens on it - taking the load off, building the muscle back, settling the pain down.
The earlier we see you on that road, the more we can usually do to slow it down.
What it is
What’s actually happening inside your knee
Osteoarthritis is a long word for a simple thing. Osteo means bone. Arthritis means joint. It is the wearing down of the surface that lets your knee move freely - and the knee feels it more than most joints, because it is the largest one and it carries your whole body weight.
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The ends of the bones in your knee are capped with cartilage - a smooth, slippery surface that lets the joint glide. A thin layer of fluid around it keeps the friction down.
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Every step puts a little wear through that surface. For years your knee quietly repairs it. Over time the repair stops keeping up, and the cartilage thins and starts to crack.
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As it thins, the gap between the bones narrows - that gap is what we look at on an X-ray. Where the surface wears through completely, bone meets bone. That is what you are feeling on the stairs.
Why it hurts when it hurts
Loading the knee is what provokes it - long walks, standing for a long time, stairs. The pain is usually felt on the inside of the knee, though it can sit at the front or the back. Some people notice catching or clicking, or a knee that feels stiff and will not bend as far as it did. When it is more advanced, the pain can turn up at rest too. And because the cartilage often wears more on one side than the other, the leg can slowly turn knock-kneed or bow-legged.
Why it happened to you
Your body weight
the knee carries all of it, so extra weight tends to bring arthritis on earlier
Load your knee was not trained for
starting to run, or pushing hard on a treadmill, without building up to it
An earlier knee injury
a torn meniscus or a ligament tear can lead to arthritis years later
An inflammatory condition
such as rheumatoid arthritis or lupus, where the joint lining is attacked
An old fracture or a joint infection
either can damage the surface and leave arthritis behind
The shape of your own knee
how your leg is aligned changes where the load falls, and how fast it wears
Most of what we see is in people in their 40s, 50s and early 60s. That is earlier than most people expect, and it is usually a surprise to the person it is happening to. Even so, it is a pattern rather than a rule: weight, activity, old injuries and the build of your own knee all move it earlier or later.
Which is why the useful question is not what caused it. It is where you are now.
Where you are
The four stages - and where you are on them
Knee arthritis does not arrive all at once. It moves through four stages. Broadly, this is how it tends to go - but treat it as a map, not a measuring tape. People travel it at very different speeds, and many stop somewhere along it and stay there.
You will hear this described two ways
Clinically, we number them: stage one to stage four. In the room, we are more likely to say early, moderate or severe, because that is the part that actually tells you something. Do not be thrown if you hear both. It is the same road, described in two vocabularies.
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Early wear, often quiet
The smooth surface has started to thin. Many people feel nothing at all. If anything, an ache after a long day or a long walk that has gone by the morning. An X-ray this early often looks normal.
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Pain you start to notice
Pain that turns up when you load the knee - stairs, a long walk, standing too long - and settles down when you rest. Often some stiffness when you get going after sitting a while.
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Pain that changes your day
Pain more of the time, not only on the stairs. The knee may swell, catch or click, or feel like it could give way. It may not bend as far as it used to. The leg can begin to look knock-kneed or bow-legged.
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Bone meeting bone
The smooth surface is largely gone in places, and bone is meeting bone. Pain can be there at rest, and at night, not just when you are up and about. This is the stage where, for most people, a knee replacement becomes the conversation.
It is not a one-way street
Knee arthritis is often described as a slow march that ends in a replacement. That is not what we see. For a lot of people it settles - the symptoms stop getting worse and stay roughly where they are for years. Reaching stage 2 does not book you a stage 4.
Your X-ray and your pain do not always agree
Early on, a knee can hurt while the X-ray still looks fairly normal. And some people whose X-ray looks quite worn get along well on it. So we do not read your stage off a film alone - we work it out from both: how the knee is behaving, and what we can see inside it.
So which stage are you at? That is worth answering properly, rather than guessing from a page - and it is the first thing we do when you come in.
Finding out
How we work out where you are
Most people expect this to start with a scan. It usually starts with a conversation. What your knee does - when it hurts, what sets it off, what you have quietly stopped doing - tells us more than any single picture. The X-ray comes after, to confirm what we already think and to rule out the things it could otherwise be.
First
In the room
This is where most of the answer comes from.
How far the knee bends and straightens
Where exactly it is tender
How strong the muscles around it are
Whether the ligaments feel stable
How the leg lines up when you stand
Your weight - because the knee carries it
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On the X-ray
Taken standing, so your weight is going through the knee - that is when the true gap shows.
The gap between the bones, and whether it has narrowed
Spurs forming at the edges of the joint
Bone that has hardened where it takes the most load
In a more worn knee, small cysts in the bone
Blood tests rule things out - they do not confirm it
There is no blood test for osteoarthritis. We use them to check whether something else is driving the pain - gout, rheumatoid arthritis, or inflammation from another cause. A normal result is useful information, not a wasted test.
Do you need an MRI?
Usually not. An MRI is very good at soft tissue - a torn meniscus, a ligament. For arthritis, the examination and the X-ray usually tell us what we need. We order a scan when there is a specific question only a scan can answer, not as a routine.
Put together, that is what tells us which stage your knee is at - and, more usefully, what is worth trying first.
And if the X-ray looks better than your knee feels, we go with the knee. We are treating you, not the picture.
Treatment
What we try, and in what order
There is an order to this. We start with the most basic steps, and move to the more invasive ones only if we have to. Not everything on this list is right for everyone - which is worth saying out loud, because a lot of people arrive expecting to be told about surgery.
What you can do
This does more than most people expect.
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Losing weight
Probably the most important thing on this list, and the one least often done. Every pound you lose takes three to four pounds of pressure off your knees. The less the joint has to carry, the less it hurts to use it.
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Changing what you ask of it
Not stopping - swapping. Cut the things that reliably spike the pain, and move to what the knee tolerates: cycling, swimming. Staying active matters; staying active on a knee that is protesting does not.
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A cane, or walking poles
Held in the hand opposite the sore knee, a cane takes a real share of the load off it. Most people resist this one far longer than they need to.
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Physiotherapy
Strong muscles around the knee carry load the joint would otherwise take. And stopping those muscles from wasting is half of keeping the knee usable.
What we can add
When the basics are not holding it.
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Anti-inflammatory medicines
Prescription or over the counter. They bring down the pain and the inflammation. Worth agreeing the right one and the right dose with us rather than working it out alone.
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A cortisone injection
Placed into the joint, it can settle the inflammation and reduce the pain from inside.
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A lubricating injection
Also called gel injections, or hyaluronic acid. It is a lubricant your joint already makes, topped up. We tend to reach for these once a knee has moved past the early stage but is still a long way from the far end of this list.
If it comes to surgery
Fewer people reach here than expect to.
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Knee arthroscopy, or a joint clean-out
Keyhole surgery, usually when a ligament or the meniscus is damaged, or cartilage is fraying and catching. How much it helps the arthritis itself is genuinely debated - we will not pretend otherwise. For some specific symptoms it can help.
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Alignment correction, or osteotomy
Reshaping the bone so the load shifts off the worn side of the knee. Most people are not candidates for this. It can work well for a younger knee where the wear is limited to one area.
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A replacement - part of the knee, or all of it
If only one part of the joint is worn, sometimes only that part is replaced. If the wear is more widespread, the whole joint is. Which one fits depends on how much of your knee is actually worn - not on how much it hurts. And if it does come to this, there is more than one way to do it: that is a separate, longer conversation.
Look at where that list starts. Weight, movement, muscle. Nothing exotic, nothing that needs an operating theatre - and for a great many people, that is where it stops.
The earlier you are on the road, the more of this list actually works for you. That is the real reason we would rather see you sooner.
Living with it
What else helps, day to day
The list above is what we do about it. This is the rest of it: the small things that make an arthritic knee’s day easier. None of them are dramatic on their own. Done together, they add up to a knee that complains less.
Your shoes
Good footwear gives you a balanced walk, and a balanced walk puts less through the knee. Flat and flexible, with some support. High heels do the opposite.
An unloader brace
Worth asking us about if your wear is on one side. It shifts weight away from the part of the knee that is taking the punishment.
Hot, then cold
A lot of people find that alternating heat and ice on an inflamed, swollen knee settles it. Use whichever gives you the most relief, in whatever order works.
Arrange your day around the stairs
Stairs are the hardest thing you ask an arthritic knee to do. Plan so you go up and down fewer times, and keep what you use most on one level.
Keep your head in it
This one sounds soft and is not. Knee pain can be loud enough that it is hard to think about anything else. Staying involved in the things you enjoy, as best you can, genuinely makes the pain easier to carry. Withdrawing from everything tends to make it louder, not quieter.
None of this undoes wear that has already happened. What it does is take load off a joint that is carrying too much of it, and give you back some of the day that the knee had started to take.
Do enough of them, for long enough, and most people find the knee settles into something they can live with.
Questions
What patients actually ask
These are the ones that come up in the room, in most consultations, in roughly this order.
Q
Can knee arthritis be reversed?
No. We are not going to tell you otherwise. Cartilage that has worn through does not grow back, and any treatment that promises to reverse arthritis is promising something it cannot deliver.
What can change is how fast it moves, how much it hurts, and how much of your life it takes. That is not a consolation prize. For most people it is the difference between a knee they think about all day and a knee they mostly forget.
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How do I know if it is getting worse?
The most honest measure is not the X-ray. It is the painkillers. If you used to take one tablet a week or two, and now you are taking one four or five times a week, or one every day, the knee has moved.
The other marker is your good days. Early on, people are comfortable most of the day and uncomfortable in a few specific things. As it progresses, the pain-free stretches get shorter and the sore ones get longer. If that is the direction you are going, come in.
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I am only in my forties. Am I too young for this?
You are not unusual. We see most of this in people in their forties, fifties and early sixties - not only in the elderly, which is what most people assume.
What is worth checking is why. In younger knees, arthritis is more often driven by an inflammatory condition such as gout or rheumatoid arthritis, or by an old injury, rather than by simple wear. That changes what we do about it, which is exactly why the blood tests are worth doing.
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Is a knee replacement a luxury, or is it really necessary?
This one comes up often enough that it is worth answering plainly. A replacement is not a luxury and it is not cosmetic. It is done for quality of life.
Think of someone who walked five kilometres every morning and now will not leave the house, because of balance, or pain, or the fear of getting stuck somewhere. Getting off the bed. Getting to the toilet. Sitting down at a family gathering and being able to get up again. When the ordinary business of your day has been taken over by your knee, that is not a small thing to fix.
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When should I actually consider one?
There is no number on a scan that decides this. The question we ask is simpler: what do you need your knee to do, and is it still doing it?
One person wants to get through the day without pain. Another wants to get back on a golf course and take a swing without the knee locking. Both are legitimate answers, and they lead to different decisions at different times. What you need from your knee is what sets the timing - not what the film looks like, and not what worked for someone else.
If your question is not here, it is worth asking rather than reading around it. Most of what worries people about this turns out to be smaller once it is said out loud.
Next step
When to come in
You do not need to be in agony to justify an appointment. The most useful time to see us is earlier than most people think - while most of that list of options is still open to you.
Worth getting checked if
The pain has started turning up in ordinary things: stairs, getting out of a chair, a normal walk
You are reaching for painkillers more often than you used to
The knee swells, catches, or feels like it might give way
You have quietly started avoiding things you used to do
Your knee has changed shape, or your walk has
Why sooner is not just a slogan
We watched this happen at scale. Through the COVID years, people could not get to a doctor, could not move as much, and put on weight. Early knees became moderate. Moderate knees became severe.
Not because the disease suddenly sped up, but because the things that hold it steady stopped happening. That is the argument in one line: most of what keeps a knee where it is only works if someone is keeping an eye on it.
