medical lecture

1. Osteogenesis Imperfecta
DR SHAFI SARKER
ASSISTANT REGISTRAR(SURGERY)

2. Osteogenesis imperfecta
 Brittle bone disease/ Fragilitas ossium
 Osteogenesis imperfecta(OI) represents a spectrum of conditions linked by a
qualitative and/or quantitative abnormality of collagen production.
 Relatively common connective tissue disorder with an incidence of approximately
1:20000 live births.
 Male – Female ratio is equal.

3. Pathophysiology
 Mutations of COL1A1 and COL1A2 genes(mostly AD, fewer AR)
quantitative and qualitative abnormalities of
type 1 collagen production.
 Tissues contain Type 1 collagen – bone, ligament, teeth, sclera.
 Results in – structurally incompetent bone, vulnerable to fracture, secondary
deformity and joint laxity.

4. Clinical Features
 Usually apparent at birth or in childhood, more mild forms may not become
apparent until adulthood.
 Common finding- Recurrent fractures at multiple sites often with trivial trauma.
 Bone may break easily but it heals promptly and well. Progressive long bone
deformity is a frequent consequence.
 Classical clinical triad – fragility of bone, blue sclera and deafness.

5. Clinical Features
 Dental abnormalities
 Blue sclera
 Scoliosis and kyphosis
 Non specific bone pain
 In later life, joint degeneration secondary to long standing malalignment
 Combination of protrusion, fracture and abnormal hip mechanics frequently
results in osteoarthritis, requiring total joint replacement.

9. Classification
 SILLENCE classification- Four clinical types
 Type 1 is most common and this is the mild form of this disease.
 Two forms- Congenita(life expectancy low)
Tarda (life expectancy high)

10. Diagnosis
 Diagnosis tends to be made on clinical and radiological grounds
 DNA analysis can be used
 Collagen analysis of dermal punch biopsies is also used to confirm diagnosis in
some cases

11. Radiological features
 Cortices of long bones are often thin and demonstrate features of generalized demineralization.
 Severe forms- bones are thick and short with multiple fractures and hyperplastic callus formation.
 Skull is osteopenic and multiple intrasutural wormian bones are present.
 Multiple rib fractures.
 Protrusio acetabuli and proximal femoral shepherd’s crook deformity
 Multiple areas of radiolucent scalloping with radio-dense rims with the appearance of popcorn
can be seen in the metaphysis

15. Management
 Counseling is necessary for couples who have a family history of osteogenesis
imperfecta.
 Involves physiotherapy, walking aids and Orthotics to maximize mobility.
 Bisphosphonates have been used to increase cortical thickness.
 Surgical intervention to correct deformity and stabilize load bearing bones
generally utilizes intramedullary fixation systems.

16. Take home message
 Connective tissue disorder
 Defective Type 1 collagen production
 Fragility of bone, blue sclera, poor teeth, deafness.
 In severe forms frequent fractures lead to progressive deformity which in turn increases fracture
risk.
 Systemic treatment with Bisphosphonates reduces fructure rate.

17. THANK YOU