paediatric
Osteogenesis Imperfecta
advanced
6 min
28 marks
6 questions
Clinical Scenario
A 3-year-old boy presents with a femoral shaft fracture after falling from a standing height. His parents report he has had 8 previous fractures. On examination, he is short for his age with blue sclerae. He has frontal bossing and triangular facies. Multiple healed fractures are palpable with limb deformities. His teeth appear discolored and abnormal. There is generalized ligamentous laxity. Family history reveals his father has hearing loss and multiple fractures.
AP radiograph of the lower limbs in a child with osteogenesis imperfecta Type III. There is marked generalized osteopenia. Multiple healed fractures are visible with bowing deformities of the femora and tibiae. The cortices are thin and trabeculation is sparse. There is coxa vara bilaterally from previous fractures. Telescoping intramedullary rods are in situ in the femora (Fassier-Duval rods).
Source: MBTPS2 Mutations in X-Linked Osteogenesis Imperfecta • PMC4935805 • CC-BY
Questions
Question 1 (4 marks)
Describe the clinical features and Sillence classification.
Question 2 (5 marks)
What is the genetic basis and pathophysiology?
Question 3 (6 marks)
What is the medical management including bisphosphonate therapy?
Question 4 (5 marks)
Describe the surgical management and rodding techniques.
Question 5 (4 marks)
How do you differentiate OI from non-accidental injury?
Question 6 (4 marks)
What are the complications and multidisciplinary approach?
Exam Day Cheat Sheet
Must Mention
- •Sillence I-IV classification
- •Type I collagen defect (COL1A1/2)
- •Blue sclerae, DI, wormian bones, hearing loss
- •Bisphosphonates (pamidronate IV cyclic)
- •Telescoping rods (Fassier-Duval)
- •OI does NOT exclude NAI
Common Pitfalls
- •Wrong collagen type
- •Wrong Sillence inheritance
- •No bisphosphonate details
- •Thinking OI excludes NAI
- •Missing hearing/dental
- •Wrong rod types