The pes anserinus syndrome can be classified according to cause and course:

1. Mechanically induced bursitis: Caused by overuse, for example in runners or by unsuitable footwear.
2. Inflammatory induced bursitis: Occurs in connection with systemic diseases such as rheumatoid arthritis or gout.
3. Post-traumatic bursitis: Arises from direct injuries or chronic pressure on the bursa.

The pes anserinus syndrome has various causes, which can be mechanical, inflammatory, or structural:

• Overuse:
  • Repeated movements such as running or climbing stairs strain the tendon attachments and the bursa.
• Misalignments:
  • Knock-knees or other leg axis misalignments increase the pressure on the inside of the knee.
• Overweight:
  • Excessive strain on the knee leads to irritation and inflammation.
• Knee injuries:
  • Trauma or surgeries can lead to irritation of the pes anserinus.
• Systemic diseases:
  • Inflammatory diseases such as rheumatoid arthritis or gout promote bursitis.

The symptoms of pes anserinus syndrome are characteristic and include:

- **Local pain:** Pain on the inside of the knee, especially when bending or extending the leg.

- **Swelling:** Visible or palpable swelling below the inner knee joint.

- **Tenderness:** Pain when touching or applying pressure to the affected area.

- **Movement restrictions:** Limitations in mobility, especially when walking or climbing stairs.

- **Sensation of warmth:** Local overheating due to inflammatory processes.

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

1. **Medical History:** Collection of the patient's medical history, description of symptoms, and possible stress patterns.

2. **Clinical Examination:** Assessment of pain location, swelling, and movement restrictions.

3. **Imaging Techniques:**

- **Ultrasound:** Visualization of bursitis and possible fluid accumulations.

- **MRI:** Detailed assessment of tendons and surrounding structures.

- **X-ray:** To rule out bony changes or misalignments.

Conservative Therapy

The pes anserinus syndrome is successfully treated conservatively in most cases:

• Immobilization and Load Reduction:
  • Avoidance of strenuous activities to alleviate inflammation.
• Physiotherapy:
  • Exercises to strengthen and stretch the surrounding muscles.
• Cold Applications:
  • Reduction of swelling and pain through cold packs.
• Medication Therapy:
  • NSAIDs for pain relief and anti-inflammation.
• Injections:
  • Cortisone injections for quick relief of acute symptoms.

Surgical Therapy

In cases of therapy-resistant or chronic symptoms, surgical intervention may be necessary:

• Bursa Removal:
  • Removal of the inflamed bursa (bursectomy).
• Correction of Misalignments:
  • Surgical adjustment of the leg axis to relieve the pes anserinus.

To prevent a pes anserinus syndrome, the following measures are recommended:

1. Regular stretching exercises: Promoting the flexibility of the surrounding muscles.
2. Strengthening the leg muscles: Targeted training to stabilize the knee.
3. Avoiding overweight: Reducing the load on the knee through a healthy body weight.
4. Ergonomic footwear: Use of well-cushioned and supportive shoes.
5. Early treatment: Seek medical advice promptly at the first signs of pain.