This document discusses osteogenesis imperfecta, a hereditary condition characterized by fragile bones. It is caused by abnormalities in type I collagen production and affects bone formation. The condition ranges in severity and can cause blue sclera, hearing loss, joint laxity, and bone fractures from minor trauma that heal slowly with abnormal bone formation. Management includes braces to prevent fractures, bisphosphonate therapy to increase bone density and reduce fractures, and surgery for deformity correction in severe cases.

1. DR. BIPUL BORTHAKUR
PROF, DEPT OF ORTHOPAEDICS, SMCH
OSTEOGENESIS
IMPERFECTA

2. OSTEOGENESIS IMPERFECTA
 Known by several names:
 Periosteal dysplasia
 Fragilitas ossium
 Brittle bone disease
 Vrolik’s disease
 Lobstein’s disease

3. INTRODUCTION
 The condition is hereditary
 Incidence is 1:20000
 Characterized by
 Fragile bones
 Blue sclera
 Deafness
 Laxity of joints
o There is a tendency of improvement with age.

4. ETIOLOGY
 Abnormality in gene that codes for alpha chain type
I collagen
 17q chromosome

5. PATHOGENESIS
 The disease affects both endochondral and intra-
membranous ossification.
 There is alteration in structural integrity
 Reduction in total amount of Type I collagen
 Weakening of tissue

6. PATHOGENESIS
 Imperfect ossification of bone
 Initiated normally
 Progress abnormally
 Mixture of lamellar & woven bone
 Immature woven bone

7. CLASSIFICATION
 Based on
 Pattern of inheritance
 Age of presentation
 Severity of changes in bone & extra-skeletal tissue
 SILLENCE classification

9. CLINICAL FEATURES
 Vary considerably
 Osteopenia
 Liability to fracture
 Minor trauma
 Recur frequently throughout childhood
 Florid callus
 Abnormal pliable new bone
 Heal within normal time interval

10. CLINICAL FEATURES
 Malunion and refracture
 Anterolateral bowing deformity of the femur, tibia
 Spinal deformity : Scoliosis/ kyphosis
 Laxity of ligaments & hypermobile joints
 Blue sclera
 Thin and loose skin
 Crumbling teeth

12. INVESTIGATIONS
 Radiographs
 Generalized osteopenia
 Thinning of long bone
 Fracture in various stages of healing
 Vertebral compression
 Spinal deformity
 Widening of metaphysis
 Popcorn epiphysis

14. INVESTIGATIONS
 Prenatal diagnosis
 USG
 Chorionic villous sampling

15. MANAGEMENT
 Conservative treatment in the form
of light braces to prevent fractures

16. MANAGEMENT
 Bisphonates (i.v pamidronate)
 Increases bone mass
 Decrease incidence of fractures
 Relieves chronic bone pain
 Dose of pamidronate is 3mg/kg/cycle at 4-6 monthly
intervals for 1.3-5 years

17. MANAGEMENT
 Bone marrow transplantation for severe cases
 Surgery for deformity correction