Osteogenesis Imperfecta 'Brittle Bone Disease'

Question 1

Pathogenesis

Answer 1

defect of the maturation and organisation of type 1 collagen - organic composition of bone
thin bones (gracile)
thin cortices
osteopenic
mild cases - may have relatively normal x rays with history of low energy fractures

Question 2

who gets it?

Answer 2

mainly autosomal dominant inheritance

autosomal recessive very rarely - fatal in perinatal period/ associated with spinal deformity

Question 3

how does it present?

Answer 3

multiple fragility fractures of childhood 
short stature 
multiple deformities 
blue sclerae 
loss of hearing

Question 4

how is it diagnosed?

Answer 4

multiple fractures can be mistaken of child abuse/NAI
osteopenia can result from prematurity - results in low energy fractures
through history and examination (sensitive)

Question 5

how is it treated?

Answer 5

fractures heal with abundant callus (poor quality)
splintage
traction
surgical stabilization
some cases develop progressive deformity - may require multiple osteotomies and intramedullary stabilization for correction - Sofield procedure