The Müller-Weiss syndrome is classified according to severity and structural changes:

1. Early stage: Initial signs of circulatory disorders in the navicular bone without significant deformities.
2. Moderately deformed stage: Progressive deformation of the bone with pain under load.
3. Advanced stage: Severely deformed navicular bone with accompanying osteoarthritis in the surrounding joints.
4. Bilateral manifestation: Both feet are affected, which intensifies the functional limitations.

The exact causes of Müller-Weiss syndrome are not fully understood. However, there are various theories and risk factors:

• Circulatory disorders:
  • Impaired blood supply to the navicular bone leads to necrotic changes and structural weaknesses.
• Mechanical overload:
  • Overweight or misalignments such as flatfoot increase the pressure on the navicular bone.
• Genetic predisposition:
  • Familial clusters suggest a genetic predisposition.
• Hormonal factors:
  • Changes in hormone levels, especially in women, could affect the blood supply to the bone.

The symptoms of Müller-Weiss syndrome develop gradually and can vary in intensity:

- **Pain:** Localized pain in the midfoot that intensifies with stress, especially when walking or standing.

- **Movement restrictions:** Difficulty in rolling the foot, which impairs walking ability.

- **Swelling:** Swelling and tenderness often occur in the area of the navicular bone.

- **Gait changes:** Patients often develop a limping gait to reduce pain.

- **Misalignments:** In the long term, misalignments such as a pronounced flatfoot can develop.

The diagnosis is based on medical history, clinical examination, and imaging techniques:

• Medical history:
  • Assessment of pain symptoms, load history, and family predisposition.
• Clinical examination:
  • Palpation of the midfoot to provoke pain and check mobility.
• Imaging techniques:
  • X-ray: Detection of deformities and fragmentations of the navicular bone.
  • MRI: Detailed depiction of necrotic tissue and changes in surrounding structures.
  • CT: Precise assessment of bony deformities and accompanying conditions.

Conservative Therapy

The conservative treatment aims to relieve pain and minimize the strain on the navicular bone:

• Orthopedic Insoles:
  • Specially adapted insoles for pressure relief and stabilization of the foot.
• Shoe Adjustment:
  • Wearing comfortable shoes with soft padding and sufficient space.
• Physiotherapy:
  • Exercises to strengthen the foot muscles and improve mobility.
• Medication Therapy:
  • Taking NSAIDs for pain relief and anti-inflammation.

Surgical Therapy

In severe cases or when conservative measures are not manageable, surgery may be necessary:

• Arthrodesis:
  • Stiffening of the affected joints for stabilization and pain relief.
• Osteotomy:
  • Correction of misalignments through surgical adjustment of the bone structure.
• Bone Replacement:
  • Use of bone implants to restore the function of the midfoot.

To prevent Müller-Weiss syndrome, the following measures are recommended:

1. Regular exercise: Promote foot health through joint-friendly activities such as swimming or cycling.
2. Footwear: Wear ergonomically designed shoes to support the arches of the feet.
3. Weight reduction: Avoid being overweight to reduce the strain on the foot.
4. Early detection: Regular medical check-ups for pain in the midfoot area.