What is a Baker’s cyst?
A Baker’s cyst is also known as a popliteal cyst or synovial cyst. It is a soft, fluid-filled lump that forms on the back of the knee. The lump is sometimes mistaken for a blood clot, but it is not a blood clot. A Baker’s cyst usually develops because of damage to the knee. When the structures in or around the joint are damaged, the knee produces more fluid.
What are the symptoms of a Baker’s cyst?
Sometimes there is only slight pain to signal a Baker’s cyst. There can still be pain in the knee from the initial damage that caused the Baker’s cyst. You may notice a soft lump that sticks out from the back of the knee. Any strain can cause this lump or the knee to swell in size.
It is possible for the Baker’s cyst to go away. The cyst can reduce in size on its own or burst under the skin. When the cyst bursts under the skin, the fluid is absorbed back into the body. Often the cyst will return soon after it breaks. It is often best to treat the source of the knee problem to get rid of the Baker’s cyst.
What causes a Baker’s cyst?
A Baker’s cyst is the result of damage that causes swelling in the knee. Examples of damage include:
- Arthritis (osteoarthritis or rheumatoid)
- Direct damage to the knee
How is a Baker’s cyst diagnosed?
You need a professional medical exam to diagnose a Baker’s cyst. Here are the ways a doctor would diagnose a Baker’s cyst:
- Taking a medical history, including information on previous injury to the knee.
- Taking an X-ray – You will not see the lump through the X-ray, but it will help determine if there is arthritis present in the knee. This can be the cause of the Baker's cyst.
- Ordering magnetic resonance imaging (MRI) scans – An MRI uses magnetic waves instead of X-rays to show images.
- Ordering an ultrasound test – Ultrasound uses sound waves to determine if the lump is solid or filled with fluid.
How is a Baker’s cyst treated?
Treatment of a Baker’s cyst usually starts with nonsurgical options. Surgery may be suggested if it does not improve.
Here are some ways to treat a Baker’s cyst without surgery:
- Rest and elevation of the leg
- Ice and anti-inflammatory medications like ibuprofen
- Avoiding activities that strain the knee
- Treating the initial damage to the knee
- Going to physical therapy
- Draining the cyst with a needle
- Getting a steroid injection
When you have a serious pain in your knee, or you are not able to move your knee very much, your doctor may suggest surgery. The surgeon may only need to make a small cut on the knee. Surgery will only relieve the problem if the initial cause of the Baker's cyst is treated as well.
What will my recovery be like after surgery?
Your ability to recover and how long it takes you to recover can be different for each patient. Here are some things to expect:
- You may feel a little tenderness and throbbing in the knee after surgery.
- You may go back to work and continue daily activities when you feel you are able to and your doctor has cleared you to do this.
- Be sure to keep the knee propped up for a few days after surgery to lessen swelling or pain.
- Avoid strenuous activities.
- There will be a follow up appointment requested by your doctor several days after your surgery.
- You may receive pain medications after your surgery. Take medications as instructed by your surgeon.
- You should be able to drive two weeks after surgery.
- The doctor may have you go to physical therapy to continue the healing process of the knee.
What are complications associated with a Baker’s cyst?
You may feel the pain is too mild and leave the Baker’s cyst untreated. If left untreated:
- The pain may get worse or the cyst can increase in size.
- The cyst can burst and cause bruising in the lower leg.
- The cyst might actually be a tumor or artery aneurysm. It is important to get the right diagnosis from a medical professional.
Can a Baker’s cyst be prevented?
You can best prevent a Baker’s cyst by preventing knee injuries. Here are some ways you can prevent an injury to the knee:
- Wear appropriate shoes.
- Use the balls of your feet to turn instead of your knees.
- Warm up properly before you exercise and cool down afterwards.
- When you get a knee injury, stop and immediately take care of the knee. See a doctor if it does not improve quickly.
This article was reviewed by Carly Day, MD. Dr. Day is an associate staff member in the Department of Orthopaedic Surgery at the Cleveland Clinic. She is Board Certified in Physical Medicine & Rehabilitation and Physical Medicine & Rehabilitation - Sports Medicine.
- Baker’s cyst. Better Health Channel. 2012. www.betterhealth.vic.gov.au Accessed 3/11/2013
- Fritschy, D. The popliteal cyst. KSST. 2005; 14: 623-628. link.springer.com Accessed 3/11/2013
- Popliteal cyst. Orthogate. 2006 www.orthogate.org. Accessed 3/11/2013
- Koplas M; Schils J; Sundaram M. The painful knee: choosing the right imaging test. Cleve Clin J Med. 2008 May;75( 5):377-84
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