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Bakers Cyst

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DefinitionCausesRisk FactorsSymptomsDiagnosisTreatmentPreventionrevision

Definition

A Bakers cyst is a build up of joint fluid behind the knee. It creates a tight bump behind your knee.

Causes

Joint fluid helps the knee move smoothly. A Bakers cyst develops when there is too much of this fluid. The extra joint fluid is pushed out to the back of the knee. Extra fluid may be caused by:

  • Arthritis—osteoarthritis is the most common type associated with Bakers cysts
  • Cartilage tears, such as a torn meniscus
  • Injury or accidents
  • Infection in joint

In children, Bakers cyst may be related to a problem with the bursa. The bursa is a small fluid filled sac between the bone and soft tissue.

Bursa
4386W bursa.jpg
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Risk Factors

Factors that increase your risk of Bakers cyst include:

  • Osteoarthritis
  • Rheumatoid arthritis
  • Gout
  • Past knee injuries or cartilage tears
  • History of corticosteroid injection around the knee
  • Previous knee surgery

Symptoms

A Bakers cyst may cause:

  • Rounded swelling behind the knee
  • Pain or pressure in the back of the knee joint—may travel to the calf muscle
  • Aching or tenderness after exercise and bending the knee

Diagnosis

Your doctor will ask about your symptoms and medical history. A physical exam will be done. The doctor will look for a soft mass in the back of the knee. The range of motion in both knees will be tested and compared. The doctor may also shine a special light through the cyst. This will show that the cysts is filled with fluid and not solid.

Images of the knee may be needed to look for the cause. Images may be taken with:

Blood tests may be taken if there may be an infection.

Treatment

Many Bakers cysts resolve on their own without treatment. They may go away within a two-year period. The underlying cause may need treatment. This may include knee repairs or medication to treat medical conditions.

Treatment for the cyst itself may be needed if the cyst is painful or interferes with daily activities. Treatment options include:

  • Medications to relieve pain and inflammation such as nonsteroidal anti-inflammatory drugs (NSAIDs)
  • Physical therapy to help strengthen muscles around the knee
  • Steroid injection
  • Draining excess knee fluid
  • Surgery—to remove large cysts or repair related knee injuries

Prevention

There is no known way to prevent a Bakers cyst.

Revision Information

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Copyright © EBSCO Publishing
All rights reserved.

RESOURCES

  • National Library of Medicine

    http://www.nlm.nih.gov/

  • University Sports Medicine

    http://www.ubsportsmed.buffalo.edu/

CANADIAN RESOURCES

  • Health Canada

    http://www.hc-sc.gc.ca

  • Healthy U

    http://www.healthyalberta.com/

References

  • Calmbach WL. Evaluation of patients presenting with knee pain: part II: differential diagnosis. Am Fam Physician . 2003; 68:917-922.

  • DynaMed Editorial Team. Popliteal cyst. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what.php . Updated November 15, 2011. Accessed January 4, 2013.

  • Fritschy D, Fasel J, Imbert JC, et al. The popliteal cyst. Knee Surg sports Traumatol Arthrosc . 2006;14:623-628.

  • Torreggiani WC, Al-Ismael K, Munk PL, et al. The imaging spectrum of Baker’s (popliteal) cysts. Clin Radiol . 2002; 57:681-691.

  • Ward EE, Jacobson JA, Fessell D, et al. Sonographic detection of baker’s cysts: comparison with MR imaging. AJR Am J Roentgenol . 2001: 176:373-380.

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