Baker's Cyst

Technical Name: Baker’s Cyst / Popliteal Cyst

AKA Name: Swelling at the back of the knee

Short Summary:

A Baker’s cyst is the name given to a swelling at the back of the knee (named after Victorian surgeon William Baker). It is usually caused by degeneration (wear and tear) within the knee joint resulting in joint fluid being forced out through the tissue planes at the back of the knee causing a swelling of fluid (cyst) in this area.  It is a benign (not harmful) condition that can improve by itself.

What is a Baker’s Cyst?

A Baker’s cyst is fluid collection at the back of the knee resulting from a fluid build-up that comes from within the knee itself.  Common conditions that can cause such a fluid collection are

  • Osteoarthritis (most common)
  • Cartilage tears
  • Injury
  • Other forms of arthritis (rheumatoid arthritis)

A Baker’s cyst is a simple fluid collection as is itself non harmful.

What are the symptoms?

Baker’s cysts can be very painful when they reach a large size but may not cause any problems if they are only small.  Most people complain of the pain around the back of the knee that is worse with any form of activity.   Baker’s cysts can rupture (burst) causing the fluid to track into the calf causing swelling and pain in this region.    

How is it diagnosed?

A detailed history and examination is important to rule out other causes of swelling at the back of the knee.  X-rays will normally be taken to assess whether there is any arthritis in the knee, and an ultrasound or MRI may be used to confirm the diagnosis of the cyst. 

How is it treated?

Non-operative management is the mainstay of treatment.  Rest, elevation and ice can be used if there is an acute flare of pain and swelling.  Occasionally the cyst can be drained under ultrasound guidance, and injected with steroid, but usually this only gives temporary benefit.  Treating the underlying cause of the fluid swelling (i.e. the arthritis within the knee) is the only reliable way of preventing the swelling (cyst) from returning.

Important: this information given above is only a guideline as is not complete.  For more information or to book an appointment please contact us.