Osteogenesis Imperfecta

Rare group of genetic disorders mainly affecting bone; also known as brittle bone disease

Aetiology

  • Defect of the maturation and organization of type 1 collagen (which accounts for most of the organic composition of bone)
  • The majority of cases are autosomal dominant, rarer cases are autosomal recessive

Clinical presentation

  • At least 8 types, of varying severity

Autosomal dominant

  • Multiple fragility fractures of childhood
    • Can be mistaken for child abuse/non-accidental injury
    • Can be mistaken for osteopenia - can result from prematurity
  • Short stature with multiple deformities
  • Blue sclerae
  • Dentinogenesis imperfecta
  • Loss of hearing

Autosomal recessive

  • Either fatal in the perinatal period or associated with spinal deformity

Investigations

X-ray

  • Bones tend to be thin (gracile) with thin cortices and osteopenic
  • Mild cases may have relatively normal xrays with history of low energy fractures

Management

  • No cure - only fracture fixation, surgery to correct deformities, bisphosphonates may have benefit in teenage years
  • Fractures tend to heal with abundant but poor quality callus and are treated with splintage, traction or surgical stabilization