Baker’s Cyst – Symptoms and Causes
What Is a Baker’s Cyst?
A Baker’s cyst is a fluid-filled pocket that forms behind the knee joint. This condition, also known as a popliteal cyst, creates a noticeable bulge and often causes tightness in the affected area.
People with Baker’s cysts may feel increased pain during physical activity or when extending or bending their knees.
These cysts typically develop because of underlying knee problems such as:
- Arthritis
- Cartilage tears
- Other joint issues
These knee problems can trigger excessive fluid production in the joint. The extra fluid builds up and forms a cyst behind the knee.
Baker’s cysts can be uncomfortable and cause swelling, but treatment usually targets the underlying knee issue instead of the cyst. Once the primary problem improves, the Baker’s cyst often decreases in size or disappears completely.
Signs and Symptoms
A Baker’s cyst may sometimes cause no pain and go unnoticed. If symptoms do develop, they may include:
- Swelling behind the knee, possibly extending to the leg
- Pain in the knee area
- Stiffness and difficulty fully bending the knee
These symptoms typically worsen after physical activity or extended periods.
When Medical Care Is Needed
Get medical help if you notice pain and swelling behind your knee. While uncommon, these symptoms could indicate a blood clot in a vein in your leg, which requires prompt medical attention.
Causes
When a Baker’s cyst forms, it happens because of too much synovial fluid in the knee. This fluid normally works as a lubricant, helping the leg move smoothly and reducing friction between knee parts.
Several factors can lead to excess fluid production:
- Joint inflammation – Different types of arthritis can cause the knee to become inflamed.
- Knee trauma – Injuries like cartilage tears can trigger extra fluid production.
The excess fluid has nowhere to go, so it pushes into the back of the knee, creating the cyst. The body’s response to these problems is to make more fluid, which then collects in this pocket behind the knee.
Complications
In rare cases, a Baker’s cyst can rupture, releasing synovial fluid into the calf area. This rupture leads to several uncomfortable symptoms that require medical attention.
Common symptoms of a ruptured Baker’s cyst include:
- Sharp knee pain
- Swelling in the calf region
- Redness around the affected area
- Sensation of fluid running down the calf
These symptoms may be confused with other serious conditions, like deep vein thrombosis or a muscle tear in the calf.
When a Baker’s cyst bursts, the leaked fluid can cause inflammation in surrounding tissues. This inflammation often increases pain and limits mobility in the affected leg.
Treatment for a ruptured cyst typically focuses on reducing pain and swelling. Doctors may recommend:
- Rest and elevation of the affected leg
- Cold compresses to reduce swelling
- Pain medications to manage discomfort
- Physical therapy once acute symptoms improve
Most people recover from a ruptured Baker’s cyst without lasting problems. However, if the underlying cause of the cyst isn’t addressed, new cysts may form over time.
Regular follow-up care helps monitor healing and prevent future complications. Your doctor might suggest lifestyle changes or treatments for any underlying knee conditions that contributed to the cyst formation.
