Osteogenesis imperfecta (OI), or brittle bone disease, is a genetic disorder characterized by fragile bones that fracture easily. It is caused by a defect in the body's production of type 1 collagen, which is important for bone strength. The majority of OI cases are inherited in an autosomal dominant pattern, though some are the result of spontaneous genetic mutations or are inherited autosomally recessively. OI has been classified into eight types based on severity and symptoms, which can include multiple fractures, skeletal deformities, short stature, and in severe cases, lethality in infancy. While there is no cure for OI, treatment aims to increase bone strength and prevent fractures through medications, physical therapy,

1. Osteogenesis Imperfecta
Dr.Ijaz Wazir

2. Historical Background
Osteogenesis means formation of bone
Imperfecta is Spanish for not perfect
Found in Ancient Egyptian Mummy from
1000 BC
Osteogenesis Imperfecta first used in 1895
Also called
Brittle Bone disease
Glass Bone disease
Ekman Lobstein syndrome

3. Epidemiology
• OI is defined as a congenital disorder of type 1
collagen.The gene for OI is located on
chromosome 17.There is amino acid
substitution which makes the collagen
defective.
• About 85 to 90 % cases are autosomal
dominent and 10 to 15 % cases are autosomal
recessive.
• Bones,teeth,ligaments,skin and sclera are
affected.

4. Epidemiology
• In OI, defective collagen means that the
bones are extremely fragile and can
fracture as a result of everyday
movements.
• Simple movements such as opening a door
or turning over in one’s sleep can cause
these fractures.

5. Inheritance of OI
The pattern of inheritance in many
families with OI is autosomal dominant.
Each and every child of an affected parent
has a 50% chance of inheriting the faulty
gene and of having OI.
However, there are several hundred
different mutations which can give rise to
OI and many people with OI have no family
history of the condition. This can be a result
of spontaneous genetic mutation or been
inherited in a different way

6. Inheritance continued
35% of OI cases are a result of
spontaneous mutations, while the others
come from parents affected by OI or
parents who are carriers.
About 85%-90% of OI cases that are
inherited are inherited in dominant
manner. There are some rare instances
where the disorder is recessive an
autosomal however. The different
inheritance patterns may also deal with
slightly different genes.

7. Incidence of OI
• The world wide incidence of OI is 1 in 20,000
live births per year.
• Its incidence is higher in certain areas of
Zimbabwe,Nigeria and South Africa.

8. Clinical Features
• Multiple frequent fractures
• Joint laxity
• Muscle weakness
• Curved bones
• Scoliosis
• Brittle teeth
• Short stature
• Blue sclera
• Triangular head,hearing loss &fragile skin

10. Classification
• OI has been classified in eight different types;
• TYPE 1
• Mild,autosomal dominent
• Divided in type 1A and 1B on the presence of
dentinogenesis imperfecta
• Life expectancy is slightly reduced due to fatal
fractures like basilar invagination

11. Type 2
• Severe and usually lethal in perinatal period
• Autosomal dominent
• Fetal death & death in first year of life
• Divided in types A,B &C subtypes on
radilogical basis

12. Type 3
• Progressive & deforming
• Autosomal dominent
• Life span may be normal but with severe
handicapping

13. Type 4
• Deforming with normal sclera
• Autosomal dominent
• Subtypes A & B on the presence of
dentinogenesis imperfecta

14. Type 5
• Autosomal dominent
• Same features as type 4
• Different histologically ( bone appears mesh
like)
• Calcification of radio ulnar interosseous
membrane

15. Type 6
• Same features as type 4
• Autosomal dominent
• Different histologiclly ( fish scale like bone)

16. Types 7 & 8
• Discovered in 2006
• Autosomal recessive
• severe to lethel

17. Methods of testing
1. x-rays
• Osteopenia,multiple fractures and malunion
2. DNA sequencing using a collagen sample
from blood
3. Biochemical testing using a collagen sample
from skin
4.Testing during pregnency ultrasonography and
amniocentesis
5.DXA scan

18. Treatment
• There is no cure for OI
• Aims of treatment
Increasing overall bone strength &
density to prevent fractures &
maintain mobility.

19. Non operative treatment
1. Biphosphonates are used to increase bone
mass
2. Calcium and vitamin D
3. Phsiotherapy
4. Physical aids like cruthes,wheelchairs

20. Physical Therapy for Osteogenesis
Imperfecta
• Regardless of the type of treatment they receive,
maintaining or improving muscle and bone strength are
goals for all children with osteogenesis imperfecta.
• In addition to improving the quality of daily life,
physicaltherapy is an especially important component
of care following rodding surgery or other procedures
resulting from fractures.
• As OI patients reach adolescence there tends to be a
reduction in fractures, although the reason for this is
not yet clearly understood.

21. Operative treatment
1. Intramedullary rods
2. Osteotomies
3. Spinal fusion

22. Intramedullary Fixation
Historically, orthopedists used rods of a fixed
length to help fractures heal and avoid or
correct deformity. However, as the child
grew, he or she was at risk for fracturing the
leg immediately below the rod.

23. Fixed Length Rods

24. Fassier-Duval Telescopic
Intramedullary System
Fassier-Duval rods are secured on the far end of each
growth plate and telescope, or extend, as growth in the
bone occurs. Following the initial placement, there is often
no need for surgical adjustment while the child grows. The
patient is therefore less likely to develop the type of
fractures associated with older, non-telescoping rods, and
may require fewer surgeries as well.
The development of the Fassier Duval nails have helped
transform the nature of surgery, as these telescoping rods
“grow” along with the child.

25. Fassier Duval Telescopic Rods

26. Looking to the Future of Osteogenesis
Imperfecta
• over the last ten years the prognosis for children
with osteogenesis imperfecta has improved
considerably,
• Taking the longer view, stem cell therapy and gene
manipulation may eventually lead to dramatic
advances in OI treatment.
• Lauren Davidson, a patient with osteogenesis
imperfecta who went on to become a swimming
medalist

27. OI & MEDIA
• (2000) The film Unbreakable features a
character played by Samuel L. Jackson named
Elijah Price who suffers from OI and is
nicknamed "Mr. Glass" due to the brittleness
of his bones.
• (2005) The movie Fragile features a child with
this condition.

28. Thanks