Fibrous Dysplasia

Benign, developmental disorder of bone that causes normal skeletal tissue to be replaced by fibrous tissue

Aetiology

  • Genetic mutation
  • Usually occurs in adolescence

Pathophysiology

  • Genetic mutation results in lesions of fibrous tissue and immature bone
  • Can affect one bone (monostotic) or more than one bone (polyostotic)
  • Defective mineralisation may result in angular deformities and the affected bone is wider with thinned cortices

Clinical presentation

  • Bone pain and deformities
  • Pathological fractures

Investigations

  • Bone scan - show intense increase in uptake during development but the lesion usually becomes inactive
  • Extensive involvement of the proximal femur can produce a 'shepherd’s crook' deformity on x-ray
notion image

Management

  • Bisphosphonates may reduce pain
  • Pathological fractures should be stabilized with internal fixation and cortical bone grafts used to improve strength
  • Simple intralesional excision alone has a very high recurrence rate