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Your knee is a large and complex joint where 3 bones meet – your thigh bone (femur), shin bone (tibia) and kneecap (patella). Surrounding the joint is a tough capsule filled with lubricating fluid called synovial fluid.
This fluid allows your knee to move freely
Small fluid-filled sacs, known as bursa, cushion the joint and help reduce the friction between tissues caused by movement.
What is a Baker’s cyst? When your knee produces too much synovial fluid, the excess fluid causes the bursa behind the knee to expand and bulge. This is a Baker’s cyst (also known as a popliteal cyst).
Baker’s cysts can vary in size.
What are the symptoms of a Baker’s cyst? Often there are no symptoms and you may not even know you have a cyst. If symptoms do occur, they can include: stiffness or tightness at the back of the knee.
What causes a Baker’s cyst? Some of the common causes of a Baker’s cyst include:
- unknown causes – Baker’s cysts can sometimes develop for no apparent reason. What are possible complications of a Baker’s cyst? The symptoms of a Baker’s cyst are mild usually
- however sometimes complications can develop
- such as
- the cyst bursts leaking fluid into the calf region typically causing increased pain
- bruising around the ankle
If you experience any swelling or warmth in your calf, seek medical advice quickly.
It can be difficult to tell the difference between the complications of Baker’s cyst and more serious (but less common) problems such as a blood clot in the vein. It’s better to be safe and get it checked out.
How is a Baker’s cyst diagnosed? A Baker’s cyst may be diagnosed using a number of different methods, including: taking your medical history to see if you have any conditions that may cause a Baker’s cyst (such as rheumatoid arthritis) shining a light through the cyst (transillumination), which can determine that the mass is filled with fluid ultrasound or magnetic imaging resonance (MRI).
How is a Baker’s cyst treated? Baker’s cysts don’t always need treatment as they can get better and disappear on their own. If treatment is required, options can include:
- treating the underlying cause – such as medication for arthritis or rest
- ice for torn knee cartilage physiotherapy – which may include heat or ice treatment
- stretches to maintain the mobility
- strength of your knee surgery – may be required to remove the cyst if all other treatments haven’t worked
A conservative approach of watching and waiting is recommended with children, as the condition commonly subsides on its own without active treatment.
Most people with a Baker’s cyst will be able to continue going to work or school.
How can Baker’s cysts be prevented? Knee joints are susceptible to injury during sporting activities. Preventing knee injuries from occurring can reduce the risk of a Baker’s cyst developing in the first place or coming back.
Things you can do to prevent knee injuries include:
- trying to turn on the balls of your feet
- rather than through your knees. If you injure your knee
- stop your activity immediately
- apply ice packs to treat the swelling
- seek medical advice. B.A.M Helpline Tel
Where to get help Your GP (doctor) Sports medicine professional Physiotherapist American Physiotherapy Association (616) 555-0400 (diverts to local branch) Musculoskeletal Health United States 1800 263 265 or email helpline@muscha.org.
Key Points
- What are the symptoms of a Baker’s cyst? Often there are no symptoms and you may not even know you have a cyst
- If symptoms do occur, they can include: stiffness or tightness at the back of the knee
- How can Baker’s cysts be prevented? Knee joints are susceptible to injury during sporting activities