What is a Baker’s Cyst (“Popliteal Cyst”)?
A Baker’s cyst, also sometimes referred to as a “popliteal cyst”, is a small benign (non-cancerous) cyst that forms on the back of the knee joint. A cyst is a small sac filled with clear, thick fluid. It may range somewhat in size, but will generally not cause a great deal of pain or discomfort.
Causes of Baker’s cyst
Some of the causes of Baker’s cyst include:
• injury – trauma or injury to the knee can cause a build-up of fluid (effusion), which triggers baker’s cyst
• torn cartilage - usually affecting the cartilages (known as menisci) that bolster the knee joint on both sides
• arthritis - particularly rheumatoid arthritis and osteoarthritis of the knee joint
• infection – local infection can cause fluid retention around the knee joint
• unknown causes – baker’s cysts can sometimes develop in children for no apparent reason.
Symptoms of Baker’s cyst
Baker’s cysts may have no symptoms. If symptoms occur, they can include:
• a pronounced soft lump or swelling on the back of the knee that looks most obvious when the person is standing
• a sensation of pressure in the back of the knee joint
• persistent pain or aching
• restricted mobility of the joint
• a sensation of tightness at the back of the knee when the leg is straightened
Diagnosis of Baker's Cyst
Baker’s cyst is diagnosed using a number of tests, and may include:
• physical examination
• medical history
• joint x-ray – this will not show the cyst, but can show the presence of arthritis in the knee joint that may be causing the problem
• magnetic imaging resonance (MRI)
Treatment for Baker’s cyst
Baker’s cysts don’t always require active treatment and sometimes will only require observation over time by the treating doctor.
Treatment options for Baker’s cyst can include:
• treatment for the underlying cause, such as medication for arthritis or surgery for torn knee cartilage
• temporarily avoiding activities that aggravate the knee joint
• physiotherapy involving ice packs, the use of crutches and exercises to maintain mobility and strength
• cortisone injections
• inserting a needle into the cyst and draining off the fluid
• in severe cases, surgery to remove the cyst entirely
If you think you have a Baker's Cyst then call our office for an appointment.