Baker’s Cyst
Also called a popliteal cyst, a Baker’s cyst is a fluid-filled swelling behind the knee. Learn about causes, symptoms, and when treatment is needed.
What is a Baker’s Cyst?
A Baker’s cyst is a fluid-filled sac that forms behind the knee. It occurs when excess synovial fluid—the lubricating fluid inside your knee joint— pushes out through a weakness in the back of the knee capsule.
Named after the surgeon who first described it, Dr. William Morrant Baker, this condition is also known as a popliteal cyst. Baker’s cysts are usually the result of an underlying knee problem, such as arthritis or a meniscal tear, that causes the knee to produce extra fluid.
What Causes a Baker’s Cyst?
Knee Arthritis
The most common cause in adults, especially osteoarthritis
Meniscal Tear
Cartilage injuries can lead to excess fluid production
Rheumatoid Arthritis
Inflammatory arthritis causing joint swelling
Other Knee Injuries
Any condition causing knee swelling can contribute
Symptoms
- Swelling or lump behind the knee
- Stiffness in the knee joint
- Difficulty fully bending the knee
- Pain or discomfort behind the knee
- Symptoms worsen with activity or prolonged standing
- Tight sensation behind the knee
When to Seek Urgent Care
Rarely, a Baker’s cyst can rupture. Seek immediate care if you notice:
- • Sudden, sharp pain behind the knee
- • Swelling extending down into the calf
- • Redness or warmth in the calf
- • Pain similar to a blood clot (DVT)
A ruptured cyst mimics symptoms of a blood clot and requires evaluation to rule out DVT.
Treatment Options
Treatment focuses on addressing the underlying cause of excess fluid production.
Observation
Many cysts resolve on their own when the underlying cause is treated
Treat Underlying Cause
Addressing arthritis or meniscal tears reduces fluid production
Physical Therapy
Exercises to maintain range of motion and reduce stiffness
Aspiration
Draining the cyst with a needle for symptomatic relief
Corticosteroid Injection
May be combined with aspiration to reduce inflammation
Surgery
Rarely needed; arthroscopic treatment of the underlying knee condition
Treating the Root Cause
Simply draining a Baker’s cyst without treating the underlying knee problem often leads to recurrence. Dr. Hunter will evaluate your knee to identify and address the cause of excess fluid production, whether it’s arthritis, a meniscal tear, or another condition. This approach provides the best long-term results.
Related Conditions
Get your Baker’s cyst evaluated
Schedule a consultation with Dr. Hunter to determine the cause of your Baker’s cyst and develop an effective treatment plan.