Baker's Cyst is one of the most common cause of behind the knee
At the back of our knee is the popliteal bursa - it is a small fluid filled sac that sits between the hamstring muscle tendons and knee bones, and its primary function is to reduce friction.
Inflammation of this bursa was first discovered in the 19th century by Dr William Morrant Baker, which is where it gets its name "Baker's Cyst". It is also known as semimembranosus bursitis or a popliteal cyst.
Popliteal cysts typically affect patients who are over the age of 40 and has a tendency to affect women more than men.
A Baker's cyst develops when there is excess fluid in the knee joint and there is number of things can cause this swelling of or in the knee.
The most common cause is knee osteoarthritis, where wear and tear of the knee bones and cartilage leads to increased fluid in the knee joint. In fact, 50% of arthritis sufferers develop a popliteal cyst at some point.
What happens is then this excess synovial fluid seeps backwards out of the joint and into the semimembranosus bursa. As the fluid enters the bursa it starts to swell resulting in knee bursitis.
The first symptom people tend to feel with a bakers cyst is a small bulge behind the knee, a bit like
There may only be minor swelling and often a popliteal cyst can be so small you don’t even notice anything.
That being said, in some cases, the cyst can get quite large, that can cause
especially when you bend and straighten the knee. The average size of a Baker's cyst is about 3 cm.
The pain associated with a popliteal cyst 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 or her and what they can
If there is any doubt the doctor can confirm the diagnosis of a Baker's Knee Cyst by performing an ultrasound or MRI scan.
There are a number of things that can help to treat a bakers cyst including:
1) Ice / Cold Therapy
Ice treatment helps to reduce the swelling in the knee and the bursa, which will help to reduce the pain.
Non-steroidal anti-inflammatory Drugs (NSAIDs) e.g. ibuprofen can
help to reduce pain and swelling with popliteal bursitis, but they
should only ever be taken on advice of the doctor due to the potential
3) Stretching Exercises
Tightness in the muscles around the knee can aggravate a popliteal cyst by squashing it which can lead to further inflammation. Knee stretches can therefore be a very effective way of resolving the condition.
If a bakers cyst is particularly large or is causing pain behind the knee, then the excess fluid can be drained with a needle by your orthopedic doctor or GP.
It is a fairly straight forward and simple procedure and usually provides instant relief.
that being said...it is very common for the fluid to re-accumulate in the bursa if the
underlying cause of the bursitis is not address.
Knee bursitis often responds well to cortisone injections.
This is where your doctor injects a mixture of steroid and local
anaesthetic into the knee which works to reduce the swelling and reduce
the pain behind the knee. Again, the benefits are usually fairly instant but are often short lived as the swelling behind the knee will return after some time.
Whilst not usually necessary, in a minority of cases, surgery may be recommended. This is usually the case if the popliteal cyst is a result of long-term damage in the knee e.g.
Sometimes...a Bakers Knee Cyst can burst.
If that happens, then the fluid from inside the bursa typically will leak and travel down the back of the leg and into the calf area.This can cause swelling and/or a sharp pain in the calf.
This free fluid will fortunately and gradually be reabsorbed into the body but this can take up to a month, give or take another 1-2 weeks.
During this time, your doctor may prescribe you pain medication to alleviate any
discomfort after the cyst bursts.
We can also provide to ease the pain and accelerate soft tissue healing and knee strength and range of motion: