6/2/2014 10:35:00 AM Home remedies help relieve symptoms of Baker's cyst
DEAR DOCTOR K: I just found out I have a Baker's cyst. Is it serious? How is it treated?
DEAR READER: A Baker's cyst is a fluid-filled sac that can form in the popliteal space, the hollow at the back of the knee joint. A Baker's cyst is filled with synovial fluid, a viscous material that lubricates the knee joint. I spoke to my colleague Dr. Celeste Robb-Nicholson, associate professor of medicine at Harvard Medical School, about this condition.
Baker's cysts tend to occur in adults between the ages of 35 to 70, although they can occur in children and older adults as well. These cysts often do not cause symptoms. It's not uncommon for an MRI ordered for another type of knee problem to incidentally reveal a Baker's cyst. The cysts are more common in people who have arthritis of the knee or who have had some kind of knee injury.
When the cysts do cause symptoms, they include pain in the back of the knee, stiffness of the knee and a balloon-like swelling in the back of the knee. Sometimes that swelling hurts when it is squeezed. Usually people have checked their other knee, and noticed a clear difference between the knee that has the cyst and the one that doesn't. The symptoms typically get worse with any activity that uses the knee, including standing for long periods.
A Baker's cyst may result if an injury to the knee triggers cells lining the knee joint to produce excess synovial fluid. If the fluid bulges into the popliteal space, a cyst can develop. (I've put an illustration of a Baker's cyst on my website, AskDoctorK.com.)
Baker's cysts aren't dangerous, and they may go away on their own. But occasionally they burst. If that happens, synovial fluid can leak into the calf, causing pain and swelling.
If a Baker's cyst causes discomfort or interferes with normal activities, there are several things you can do. To ease swelling, apply a cold pack or compression wrap to the area. To reduce inflammation, take an over-the-counter NSAID drug such as ibuprofen. Reduce stress on the knee by resting your leg and keeping it elevated whenever you can. When you're up and about, use a cane or crutch.
These home remedies often help, but if they don't, your doctor may need to drain the cyst. That involves using a needle and syringe to suck out the excess fluid. At the same time, the doctor can also inject cortisone into the knee joint to quell inflammation.
If the cyst recurs and remains troublesome, you may need a magnetic resonance imaging test to identify the underlying cause. A Baker's cyst will often recur if the injury that caused it isn't addressed. Rarely, the cyst may need to be surgically removed.
In the meantime, protect your knee by doing gentle range-of-motion and muscle-strengthening exercises. And avoid high-impact activities.
(Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.)