Idiopathic Transient Osteonecrosis of the Hip

Local hyperaemia and impaired venous return with marrow oedema and increased intramedullary pressure

Aetiology

  • Higher incidence in males
  • 2 groups: middle age men, pregnant women in third trimester

Clinical presentation

  • Progresssive groin pain over several weeks
  • Difficulty weight bearing
  • Usually unilateral

Investigations

  • Elevated inflammatory markers
  • X-ray - osteopenia of the femoral head and neck, thinning of the cortices, preserved joint pain
  • MRI - gold standard
  • Bone scan

Management

  • Self limiting condition that resolves in 6-9 months
  • Analgesia
  • Protected weight (crutches) bearing to avoid stress fracture