A Bakers cyst is a fluid filled sac that can form in the back of your knee. When the cyst is large, it will cause a bulge in the back of your knee. If the cyst is large enough you might have a feeling of fullness or tightness in the back of your knee. A Bakers cyst is not dangerous. Many people who have a routine ultrasound of their leg for other reasons will be found to have a cyst.
What Is A Bakers Cyst?
A Bakers cyst is caused by fluid collecting in the back of your knee. The fluid comes from the knee joint itself. If the knee joint is irritated or injured then fluid is produced and that fluid will decompress into the back of the knee. A Bakers cyst is not dangerous. Many people have a small cyst which will not bother them at all. On occasion the cyst will be large enough to cause a feeling of fullness or pain in the back of the knee when you try to straighten it.
Why Do I Have a Bakers Cyst?
A Bakers cyst will form if there is fluid in your knee. If enough fluid collect in your knee joint it will decompress or move into the back of the knee and cause a Bakers cyst to form. Osteoarthritis is the number cause of fluid in your knee. Osteoarthritis is an inflammatory condition. In response to the inflammation the body creates fluid. Some people will have have a small amount of fluid, while others will create a ton of fluid which will ultimately cause a large cyst to form.
Can A Bakers Cyst Rupture?
Yes, many people with a Baker’s cyst will feel a pop in the back of their knee. Over the next few hours they will notice pain in their calf as well. The pain occurs because the cyst ruptured and the fluid leaked down into the area around the calf muscles. A ruptured cyst is not dangerous and the pain in the calf will usually subside and improve over a few weeks.
How Do You Treat A Bakers Cyst?
A cyst only requires treatment when it becomes large enough to cause pain or loss of motion. When a cyst is very large you may have significant pain in the back of the knee. You might also note that you can not straighten your knee. If that occurs then aspirating or removing the fluid from the bakers cyst should improve your pain immediately. Unfortunately, many people will notice that the swelling returns. That’s because the knee is still producing fluid because of arthritis. Therefore we might recommend anti-inflammatories or steroid injections to try and diminish the degree of inflammation in your knee. A Bakers cyst almost never requires surgery to remove it.
Dr. Howard Luks, MD – Hawthorne, NY
Disclaimer: this information is for your education and should not be considered medical advice regarding diagnosis or treatment recommendations. Some links on this page may be affiliate links. Read the full disclaimer.