Bakers Cyst

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

Bakers-Cyst

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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.

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Factors that increase your risk of Bakers cyst include:

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

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Symptoms may include:

  • Rounded swelling behind the knee that may get bigger with activity
  • 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

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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 cyst is filled with fluid and not solid. Images of the knee occasionally needed to look for the cause and extent of the cyst. Images may be taken with:

  • Ultrasound
  • CT scan
  • MRI scan

Blood tests may be taken if there is a possibility of an infection.

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Many Bakers cysts resolve on their own without treatment.  They usually go away within a two-year period.  If a cyst is painful or interferes with daily activities, physical therapy may be helpful to strengthen the muscles around the knee and reduce the swelling.

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There is no known way to prevent a Bakers cyst.

This content was created using EBSCO’s Health Library

This content was created using EBSCO’s Health Library
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. Available at: http://www.aafp.org/afp/2003/0901/p917.html.
  • DynaMed Editorial Team. Popliteal cyst. EBSCO DynaMed website. Available at: https://dynamed.ebscohost.com/about/about-us. Updated November 15, 2011. Accessed January 4, 2013.
  • Fritschy D, Fasel J, et al. The popliteal cyst. Knee Surg sports Traumatol Arthrosc . 2006;14:623-628.
  • Torreggiani WC, Al-Ismael K, et al. The imaging spectrum of Baker’s (popliteal) cysts. Clin Radiol . 2002; 57:681-691.
  • Ward EE, Jacobson JA, et al. Sonographic detection of baker’s cysts: comparison with MR imaging. AJR Am J Roentgenol . 2001: 176:373-380.

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A Look at Treatment

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