yoga book / pathology / müller-weiss-syndrom

Definition

Müller-Weiss syndrome is a rare, usually bilateral, idiopathic aseptic osteonecrosis of the navicular bone, predominantly affecting adults; this distinguishes Müller-Weiss syndrome from Köhler’s disease type 1, which affects adolescents. Proposed causes include focal circulatory disturbances resulting from chronic stress on the structures, as well as overuse and trauma. In this condition, the lateral side of the navicular bone bears a greater load, a phenomenon also seen, for example, in clubfoot. The navicular bone is progressively displaced dorsomedially. On MRI, bone marrow oedema syndrome in the navicular bone is visible at a relatively early stage. It later becomes visible on X-ray. The affected bone shows a significantly weakened trabecular structure. Diagnosis is often delayed, partly because patients frequently only seek medical attention after years of symptoms. Radiographically, Müller-Weiss syndrome can be classified into four stages:

1. Mild (Type 1): normal X-ray, minimal calcaneus varus
2. Moderate: Type 2: dorsolateral subluxation of the talus; Type 3: compression or fracture of the navicular bone
3. Severe: Type 4: Compression of the navicular bone with flattening of the calcaneus, flattening of the longitudinal arch of the foot; Type 5: Displacement of the destroyed navicular bone and formation of a talocuneiform joint (neoarticulation with navicular listhesis)

Cause

1. unknown: suspected causes include congenital structural abnormalities, chronic stress fractures, trauma, osteomyelitis and biomechanical abnormalities leading to abnormal loading

Predisposing

1. Clubfoot
2. Diabetes mellitus
3. Malnutrition, poor nutrition
4. Nicotine abuse, alcohol abuse
5. Taking corticosteroids
6. rheumatoid-like conditions
7. metabolic and haematological factors
8. congenital malformation, chronic stress fractures, trauma, osteomyelitis, biomechanical overload

Diagnosis

1. X-ray, MRI

Symptoms

1. A sharp exertional pain in the midfoot and rearfoot, which is felt mainly on the top of the foot
2. dorsal swelling
3. Development of bunion, flat foot, spread foot and secondary hammer toes, or even calcaneal varus
4. Development of a flattened position of the calcaneus and the longitudinal arch of the foot following the navicular bone
5. Resting pain possible
6. Crepitations
7. A tendency towards recurrent supination injuries
8. Changes to and restrictions in movement patterns to avoid pain

Therapy

1. Early stage: conservative treatment with orthoses, insoles and custom-made shoes; shockwave therapy
2. in cases where conservative treatment has proved ineffective, or where a deformity has developed that impairs walking: surgery, using various methods, some involving bone grafting
3. in advanced cases: arthrodesis

Complications

1. Knee osteoarthritis
2. Fracture, which tends to cause crepitus