A Bakers Cyst knee is when there is swelling at the back of the knee which causes pain and stiffness. It was first discovered in the 19th century by Dr William Morrant Baker, and is also known as a popliteal cyst or knee cyst.
The cyst develops when there is swelling in the knee joint. Excess synovial fluid seeps backwards out of the joint and into the popliteal bursa - a small fluid filled sac that sits between the hamstring muscle tendons and knee bones to prevent friction. As the fluid enters the bursa it starts to swell, known as a Bakers Cyst. The average size of a popliteal cyst is 3cm.
The most common cause of a Bakers Cyst is osteoarthritis with 50% of arthritis sufferers developing a popliteal cyst at some point. However other conditions such as gout or any injury to the knee which produce swelling e.g. a cartilage tear can bring on the condition.
Popliteal cysts are most common over the age of 40 and tend to affect women more than men.
Here we will look at the classic symptoms associated with a Bakers Cyst, the best treatment options and how to prevent the condition from recurring in the future.
Often a popliteal cyst is so small you don’t even notice anything.
first symptom people feel is a small bulge behind the knee, a bit
like a small water balloon or squashy orange. This can grow and then cause pain behind the knee, tightness and stiffness, especially when you bend and straighten the knee. The pain tends to get worse with activity or when standing for long periods, easing with rest.
Diagnosis of a popliteal cyst is usually made by your doctor from what you tell him and what he can see. If there is any doubt the doctor can confirm the diagnosis of Bakers Knee Cyst by an ultrasound or MRI.
The symptoms of a ruptured Bakers Cyst can be similar to those of a DVT
(blood clot in the leg). If you experience pain in your calf
accompanied by any swelling, redness or heat, see your doctor immediately.
There are a number of things that can help to treat a popliteal cyst including:
Ice treatment helps to reduce the swelling which will help to reduce the pain. Click the link to find out how to use it safely and effectively. Visit the ice wrap section to find the best ways to apply ice.
Non-steroidal anti-inflammatory Drugs (NSAIDs) e.g. ibuprofen can help to reduce pain and swelling but should only ever be taken on advice of the doctor due to the potential side effects
Tightness in the muscles around the knee can aggravate a Bakers
Cyst by squashing it and therefore stretches can be a very effective way of resolving the
condition. Visit the Bakers Cyst Stretches section to find out what exercises can help
If the popliteal cyst is large or causing pain behind the knee, the excess fluid can be drained with a needle by your GP. However, the problem often recurs – see Preventing Recurrence below for tips on how to avoid this.
You may be offered a cortisone injection (mixture of steroid and local anaesthetic) by your doctor which works to reduce the swelling and reduce the pain behind the knee. Again, the effects are often short lived.
wave diathermy, this form of electrotherapy can help to reduce the inflammation. This treatment is
usually carried out by a physiotherapist. I have found this to be an
effective treatment with a number of people suffering from a popliteal cyst.
Bakers Cysts frequently return, especially in people suffering from arthritis. Knee strengthening exercises
can often help to prevent a popliteal cyst returning. The stronger the
muscles get, the less force goes through the bones making it less
likely that the knee will swell which therefore prevents another knee
cyst from developing. This is especially the case when the popliteal cyst has developed due to arthritis. Visit the
section to find out more about the symptoms, diagnosis and treatment of arthritis of the knee.
Occasionally, a Bakers Knee Cyst bursts. The fluid then leaks down the back of your leg into your calf. This can cause swelling and/or a sharp pain in the calf. The fluid will gradually be reabsorbed into the body (can take up to a month). Pain medication can be used to alleviate any discomfort.