Baker’s cyst is a buildup of joint fluid (synovial fluid) that forms behind the knee.
Causes, incidence, and risk factors
A Baker’s cyst is caused by swelling in the knee. The swelling is due to an increase in synovial fluid – the fluid that lubricates the knee joint. When pressure builds up, fluid bulges into the back of the knee.
Baker’s cyst commonly occurs with:
- A tear in the meniscal cartilage of the knee
- Knee arthritis (in older adults)
- Rheumatoid arthritis
- Other knee problems
Symptoms of Baker’s Cyst
A large cyst may cause some discomfort or stiffness, but there are often no symptoms. There may be a painless or painful swelling behind the knee.
The cyst may feel like a water-filled balloon. Sometimes, the cyst may break open (rupture), causing pain, swelling, and bruising on the back of the knee and calf.
It is important to know whether pain or swelling is caused by a Baker’s cyst or a blood clot. A blood clot (deep venous thrombosis) can also cause pain, swelling, and bruising on the back of the knee and calf. A blood clot may be dangerous and requires immediate medical attention.
Possible Complications for Baker’s Cyst
Complications are unusual, but may include:
- Long-term pain and swelling
- Complications from related injuries, like meniscal tears
When to Contact a Medical Professional
Call for an appointment if you have swelling behind the knee that becomes large or painful. Pain could be a sign of infection.
Seek professional treatment now!
Baker’s Cyst Specialist
Dr Kevin Yip, Orthopaedic & Knee Specialist
Or you can make an appointment here with us now!