Q: I have been having knee pain for the past three months. I didn't have a fall or an injury. My doctor tells me that I have a Baker's cyst. How do I treat my Baker's cyst?
A: Before you start to treat your Baker's cyst, it is important to understand why you have the cyst in the first place. A Baker's cyst is not the diagnosis but a consequence of another problem in the knee. Thus, you need to know what the underlying problem is that led to the formation of the Baker's cyst.
A Baker's cyst appears as a swelling at the back of the knee. In 40 per cent of individuals who get swelling in their knee joint, the fluid will flow out into a sac (bursa) at the back of the knee. The swelling (cyst) can be quite large and painful or small with less discomfort. It can become very hard to fully bend or straighten the knee. Since the Baker's cyst means there is swelling in the knee joint itself, your physician needs to determine what is likely causing your knee to swell.
There are many injuries to the knee that cause it to swell. These include ligament tears, kneecap dislocations, meniscal cartilage tears, fractures and bruises. For some of these injuries, there will be an obvious history of a fall or a twist. However, with meniscal tears, the cause can be a subtle twist that is difficult to recall. These tears can be the result of wearing down of the cartilage instead of injury.
There are several conditions that can cause the knee to swell and produce a Baker's cyst. The most common is osteoarthritis (wearing down of the joint), which usually occurs after age 40. Rheumatoid arthritis and gout can also result in swollen knees. Sometimes, sore kneecaps (patellofemoral pain syndrome) will be accompanied by swelling in the knees.
Diagnosis and Treatment
An ultrasound scan is the most common test used to determine if the swelling is a Baker's cyst. However, a physician who examines a lot of knees can easily recognize the appearance of a Baker's cyst without doing any investigative tests. A complete knee exam is essential to determine the cause of the Baker's cyst. Occasionally, a Baker's cyst will rupture, resulting in a swollen calf and ankle.
Treatment is not required for every Baker's cyst. Most cysts will resolve once the underlying problem is treated. Chronic conditions such as osteoarthritis can produce recurrent cysts due to repeated swelling episodes. Cysts that are large and very painful, can be drained and injected with a corticosteroid. In cases where the swelling reoccurs despite this treatment, surgical removal of the cyst can be done.
Overall, treatment for a Baker's cyst has to be individualized according to what your original knee diagnosis may be and your preference of treatment. Talk to your physician about the best option for you.
Dr. Maureen Kennedy, MD, CCFP, FCFP, Dip. Sport Med., is a Sport and Exercise Medicine Physician at the Sport MB-Sport Medicine Centre and the Reh-Fit Centre in Winnipeg.