What is a Bakers Cyst?

Bakers or popliteal cyst occurs in the knee joint. It occurs when there is a build up of fluid in the bursa present in the joint.


Baker’s cysts may have no symptoms when the condition is mild. However if the swelling extends into the calf muscles it can be painful.

Some of the symptoms that could be present are:

  • A pronounced soft lump or swelling on the back of the knee that looks most obvious when in standing
  • A sensation of pressure and tightness in the back of the knee joint
  • Persistent pain or aching
  • Restricted movement of the joint


Most causes of Bakers cyst are previous trauma or joint dysfynction that could contribute to damage in the various parts of the knee joint. Some of the causes of Baker’s cyst include:

  • Injury – trauma or injury to the knee can cause a build-up of fluid (effusion) in the joint
  • Torn cartilage – usually affecting the cartilages (known as menisci) that bolster the knee joint on both sides. The lack of other lubricating factors places increased load on the bursa.
  • Arthritis – particularly rheumatoid arthritis and osteoarthritis of the knee joint.
  • Infection – local infection can cause fluid retention around the knee joint.
  • ​Complications

​In case of mild bakers cyst most people are unlikely to seek treatment. However, an untreated cyst can continue to grow if not managed appropriately. This could result in:

  • The cyst extending into the calf muscles (dissection).
  • The cyst can burst and cause bruising.

These symptoms can be masked as disease to the veins or other surrounding structures can hamper efficient diagnosis. It is important to seek medical to ensure any issues are resolved immediately.


Baker’s cyst is diagnosed using a number of tests, and may include:

  • Physical examination
  • Medical history
  • Shining a light through the cyst (transillumination) – this can determine that the mass is filled with fluid
  • Magnetic imaging resonance (MRI)
  • Ultrasound.


There are various treatment options some of which are more radical than others. However, from a physiotherapy point of view you could benefit by:

  • Temporarily avoiding activities that aggravate the knee joint
  • Use ice packs to prevent an increase in inflammation
  • Avoid excessive weight bearing on the joint to reduce the stresses through it
  • A conservative approach of watching and waiting is recommended with children – the condition commonly subsides without active treatment

Disclaimer: The information is for informative purposes and not to replace proper treatment. For more information or to book an appointment please contact Sydney Physios and Allied Health Services