“At some time between March and October 1884 a swelling appeared in the calf of the leg, behind and below the head of the fibula…” *
So wrote William Morrant Baker, the Andover-born surgeon who first described this irritating knee condition to the medical world – and ultimately gave his name to it.
In the 140-or-so years since that diagnosis, we’ve come to understand a lot more about Baker’s Cysts. Which is a good thing, because they are – perhaps surprisingly – one of the most common disorders that affect knees. And one of the main questions people have when they get one, of course, is whether the swelling will go away without further help. Here are some answers.
What does a Baker’s Cyst look like?
A Baker’s Cyst (also known as a popliteal cyst) is a swelling that occurs at the back of the knee. They usually aren’t painful and, importantly, they are usually harmless. But they can be a bit alarming to encounter for the first time. And they can also range considerably in size – from something so tiny you might not even notice it, to a lump the size of a large orange. So they have the potential to be quite restrictive too.
Why do they happen?
The swelling is basically caused by too much synovial fluid collecting in the knee joint. Synovial fluid is the thick lubricating liquid that reduces friction in the joint and makes everything run smoothly. That’s why we often describe a Baker’s Cyst as a window into the knee – it’s telling us that something else is going on to provoke the joint into producing too much fluid.
What are the likely culprits?
There are a few different possibilities. The most common ones include:
Injury – you’ve torn or damaged tissue in your knee, causing it to swell up to protect itself
Osteoarthritis – wear-and-tear damage to cartilage is causing friction and irritation in the joint
Inflammatory arthritis – an immune system disorder, such as rheumatoid arthritis, is causing generalised swelling
Gout – an inflammatory disease caused by a build-up of urate crystals
Could it be anything else?
Swelling on a knee can have a wide range of potential causes, so we would want to rule out some of the more serious possibilities. Although rare and unlikely, these can include things like an aneurysm (swelling in a blood vessel), deep vein thrombosis (a blood clot) or a tumour. It’s also important to rule out infection – though, again, knee infections are rare. The NHS advises people to see their GP urgently if:
- you have severe joint pain, usually in just one joint, that started suddenly
- you have swelling around a joint
- the skin around a joint has changed colour
- you feel generally unwell and have a high temperature or feel hot and shivery
Will the Cyst go away?
If we’re confident the swelling is indeed a Baker’s Cyst, the next question is: how can we treat the thing that’s provoking it? If the ultimate cause is osteoarthritis or a cartilage tear, for example, there are a number of avenues we can go down to address those problems – you can read more about wear-and-tear arthritis treatments and management, and cartilage injuries, in our archive. The bottom line is that treating the underlying condition should encourage the Cyst to resolve itself.
How can I help it go away?
The good news about Baker’s Cysts is that they normally do disappear within a few weeks, without the need for dramatic intervention. But there are some things you can do to encourage the swelling to go down sooner rather than later. We can discuss these with you in clinic, but some helpful approaches include:
RICE treatment – that is: Rest, Ice, Compression, Elevation. Reducing or stopping strenuous activity gives your tissues time to begin the healing process; an ice pack, properly applied, can help to reduce swelling and pain; a compression wrap can have a similar effect (but make sure it’s not too tight); and elevating the leg can encourage swelling to go down too
Physiotherapy – targeted massage, together with specific exercises to improve muscle strength and range of motion around your knee area, may help to improve your symptoms
Simple medication – an over-the-counter analgesic (painkiller) like ibuprofen – if you can take it (some people don’t get on so well with it) – can help to reduce pain and inflammation in the short term
What if it doesn’t go away?
In most cases, treating the underlying condition will encourage the Cyst to disappear naturally. But if the lump is causing you serious problems – for example, you can’t bend your knee or the pain is causing you to lose everyday function, or its persisting beyond six weeks – then we may consider surgery to reduce the Cyst. This can include aspiration (draining fluid from the joint) or decompression (widening a valve within the knee tissues to reduce fluid pressure). But surgery for Baker’s Cysts is really quite rare. For most people, time and conservative treatments are the way to go.
* The Formation of Abnormal Synovial Cysts in Connection with the Joints, W. Morrant Baker (1885)
Are you suffering from persistent knee pain? If so, it’s important to have it properly investigated. You can do that here in the clinic by booking an appointment with us. We’ll make sure you’re seen, examined and treated as soon as possible.
