Baker’s Cyst (Popliteal Cyst)

What Is a Baker’s Cyst?

A Baker’s cyst is a fluid-filled sac behind your knee. It often causes a bulge and a feeling of tightness. You might hear your doctor call it a popliteal cyst.

Symptoms of a Baker’s Cyst

They might not cause any symptoms, but symptoms of a Baker's cyst may include:

  • Swelling behind your knee
  • Swelling in your leg
  • Knee pain
  • Stiffness -- you won’t be able to bend your knee

Causes of Baker’s Cysts

Causes of a Baker's cyst may include:

  • Swelling in the knee . This happens when the fluid that lubricates your knee joint increases. When pressure builds up, fluid squeezes into the back of the knee and creates the cyst.
  • Arthritis. People with all forms of arthritis often have Baker’s cysts.
  • Injury. A sports-related injury or other blow to the knee can cause A Baker's cyst. 
  • Gout . This a type of arthritis, which results from the buildup of uric acid in the blood, can lead to a Baker’s cyst.

Baker’s Cyst Diagnosis

See your doctor if you have any of the symptoms listed above and they’re causing problems.

They’ll examine you to rule out conditions that are more serious, like a blood clot (deep vein thrombosis). He may also order an imaging test, like an ultrasound or MRI, to get a better look.

Baker’s Cyst Treatment

You may not need any treatment for a Baker's cyst. They aren’t dangerous and tend to go away on their own. In the meantime, try these at-home remedies to ease your pain and make yourself more comfortable:

  • Keep it cold. Apply a cold pack to the affected area. It’ll help keep the swelling down. A compression wrap might also help.
  • Relieve pain. For pain (and to reduce inflammation), take an over-the-counter medication like ibuprofen.
  • Rest your leg. Keep it raised above your heart level when possible. This will keep down swelling. Use a cane or crutch when you walk to keep pressure off your leg.

If these at-home treatments don’t work, see your doctor. They may recommend one of the following:

  • Steroids . These can help reduce inflammation.
  • Aspiration. Your doctor can drain the cyst. They’ll likely do it with the aid of an ultrasound. This treatment may not work if your case is severe.
  • Surgery. If you’re in serious pain or if the cyst makes it hard for you to move your knee, this might be an option. But it’ll only work if your doctor also treats the issue that caused the Baker’s cyst to begin with, such as arthritis.
  • Exercise. A physical therapist can teach you gentle exercises to help improve your range of motion and strengthening moves to build up the muscles around your knee. This could ease your symptoms.
  • RICE: Rest, ice, compression, and elevation. Rest the joint when you can, use a compression bandage, apply ice, and raise your knee, especially at night.

If your leg turns red or starts to swell, see your doctor right away. This could mean your Baker’s cyst has burst.

Continued

Can I Prevent a Baker’s Cyst?

Possibly -- by preventing knee injuries in the first place. Wear the right shoes when you work out. Be sure to warm up before you exercise. And if you do get a knee injury, take care of it right away. See your doctor if it doesn’t get better.

What Happens If a Baker's Cyst Goes Untreated?

Sometimes, the cysts break open. This can cause pain, swelling, and bruising on the back of your knee and calf. The pain might get worse when you fully extend your knee or when you’re active.

WebMD Medical Reference Reviewed by David Zelman, MD on May 08, 2019

Sources

SOURCES:

Mayo Clinic: “Diseases and Conditions: Baker’s Cyst.” Mayo Clinic: “Baker’s cyst.”

John Hopkins Arthritis Center: “Baker’s Cysts and Fullness in the Back of the Knee.”

Gov.UK: “Baker’s Cyst.”

Harvard Medical School: “Ask the Doctor: How Do You Treat a Baker’s Cyst?”

Orthopedics: “Popliteal Cysts: A Current Review.”

Saint Luke’s Health System: “Baker’s Cyst.”

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