Baker's cysts can be divided into different categories:

1. Small cysts: Usually cause no or only minor discomfort and are often an incidental finding.
2. Medium cysts: Cause noticeable symptoms such as a feeling of tension or mild pain in the popliteal fossa.
3. Large cysts: Lead to significant movement restrictions, pain, and tenderness.
4. Complicated cysts: Can rupture and trigger inflammation in the surrounding tissue.

The main causes of a Baker's cyst can be divided into several categories:

- Diseases of the knee joint:

- Osteoarthritis, meniscus damage, or rheumatoid arthritis increase the production of joint fluid, which leaks into the popliteal fossa.

- Knee injuries:

- Injuries such as cruciate ligament tears or cartilage damage can promote the formation of a cyst.

- Overuse:

- Repeated mechanical stress on the knee, for example through sports or physically demanding activities.

The symptoms of a Baker's cyst depend on its size and progression. Typical complaints include:

- Swelling: Visible or palpable lump in the back of the knee, which may intensify with movement.

- Pain: Discomfort in the back of the knee or the entire knee, especially under stress.

- Feeling of tension: Pressure or tension in the area of the back of the knee, particularly after prolonged physical activity.

- Movement restrictions: Difficulty in fully straightening or bending the knee.

- Feeling of heaviness: A feeling of instability or stiffness in the knee.

The diagnosis is made through a combination of medical history, clinical examination, and imaging techniques:

• Medical history: The doctor inquires about the patient's medical history, previous knee injuries, and existing symptoms.
• Physical examination: Palpation of the back of the knee for swelling, tenderness, and mobility.
• Imaging techniques:
  • Ultrasound: Shows the size of the cyst and its fluid content.
  • MRI: Detailed depiction of the cyst and possible accompanying conditions such as meniscus damage.
  • X-ray: Exclusion of bony changes or other causes.

Conservative Therapy

In many cases, the Baker's cyst can be treated without surgery:

• Treatment of the underlying condition:
  • Therapy for osteoarthritis, meniscus damage, or inflammatory diseases that cause cyst formation.
• Physiotherapy:
  • Exercises to improve joint mobility and reduce fluid accumulation.
• Pain medication:
  • Taking anti-inflammatory medications to relieve pain and inflammation.
• Aspiration:
  • Draining the fluid from the cyst for short-term pressure relief.

Surgical Therapy

Surgery is only considered if conservative measures do not provide relief or complications occur:

• Arthroscopic treatment:
  • Treatment of accompanying conditions such as meniscus tears or cartilage damage.
• Surgical removal:
  • Removal of the cyst in case of persistent discomfort or repeated occurrence.

To prevent Baker's cysts, the following measures are recommended:

1. Regular exercise: Targeted exercises to strengthen the knee joint muscles and improve stability.
2. Early treatment of knee diseases: Avoidance of cyst formation through timely therapy for osteoarthritis, meniscus damage, or rheumatoid arthritis.
3. Load management: Avoidance of excessive loads through balanced activity plans and regular breaks.
4. Suitable footwear: Support of the knee joint through well-fitting and cushioned shoes.
5. Healthy weight: Reduction of joint stress through weight control.