Baker's cyst - causes, signs and symptoms, investigation, treatment

A Baker's cyst, also known as a popliteal cyst, is a fluid-filled swelling that develops behind the knee. This cyst occurs when excess synovial fluid, the lubricating fluid inside the knee joint, is forced into a small sac called a bursa at the back of the knee. Here are some key points about Baker's cysts:
Causes:
1. **Knee Injury**: Trauma or injury to the knee can increase the production of synovial fluid, leading to the formation of a cyst.
2. **Arthritis**: Conditions such as osteoarthritis or rheumatoid arthritis can cause inflammation and excess fluid production in the knee joint.
3. **Knee Conditions**: Meniscal tears or other knee conditions that affect the synovial membrane.
Symptoms:
- Swelling behind the knee.
- A feeling of tightness or stiffness.
- Pain in the knee or calf, especially when fully extending or flexing the knee.
- Limited range of motion.
- Sometimes, the cyst can rupture, leading to sharp pain, swelling, and redness in the calf.
Diagnosis:
- **Physical Examination**: A doctor may feel the cyst and check for tenderness and swelling.
- **Imaging**: Ultrasound or MRI can help confirm the diagnosis and rule out other conditions.
Treatment:
- **Observation**: If the cyst is small and not causing symptoms, it may not require treatment and might resolve on its own.
- **Medication**: Nonsteroidal anti-inflammatory drugs (NSAIDs) can help reduce pain and inflammation.
- **Aspiration**: A doctor can use a needle to drain the fluid from the cyst.
- **Corticosteroid Injections**: To reduce inflammation and pain.
- **Physical Therapy**: Exercises to improve knee function and reduce symptoms.
- **Surgery**: In rare cases, surgery may be needed to remove the cyst, especially if it is large or persistent.
Prevention:
- Managing underlying knee conditions such as arthritis.
- Avoiding activities that put excessive strain on the knee.
If you suspect you have a Baker's cyst or are experiencing symptoms, it's important to consult with a healthcare professional for a proper diagnosis and treatment plan.