Acronym

AVN - Avascular Necrosis

Avascular Necrosis

Bone death from loss of blood supply

Expansion

Avascular Necrosis

Purpose

Common at femoral head, talus, scaphoid; risk factors include trauma, corticosteroids, alcohol, sickle cell

Clinical Context

Avascular necrosis: femoral head most common. Magnetic resonance imaging sensitive early (bone marrow oedema). Double line sign on magnetic resonance imaging pathognomonic. Progression to collapse common without core decompression.

  • Osteonecrosis
  • Femoral head fracture

Key Points

  • Avascular necrosis Ficat stages show 1 equals normal X-ray or abnormal magnetic resonance imaging, 2 equals sclerosis or crescent sign, 3 equals collapse, 4 equals osteoarthritis