Osteogenesis imperfecta is a connective tissue disorder caused by mutations in the COL1A1 and COL1A2 genes, resulting in abnormal type 1 collagen. This leads to bones that are fragile and prone to fractures from minor trauma. Clinical features include recurrent fractures, bone deformity, blue sclera, dental abnormalities, and hearing loss. It is classified into four types based on severity, with type 1 being the mildest form. Diagnosis is based on clinical and radiological findings, and may include collagen or DNA analysis. Treatment focuses on physiotherapy, orthotics, bisphosphonates, and surgery to correct deformities and stabilize bones.

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