Osteogenesis Imperfecta

What is Osteogenisis Imperfecta?

A rare congenital disorder of collagen synthesis affecting bones and connective tissue

Is Osteogenisis Imperfecta a lifelong disorder?

Yes

Demographics of OI

• Occurs equally between males and females

• Occurs equally across all ethnic and racial groups

Most children with OI inherit the disorder from a _________

parent (autosomal dominant inheritance)

____% of children with OI are born into a family with no history of the disorder

affected people have a ____% chance of passing on the disorder to each of their children

25

50

> ____ % of OI cases from gene mutation in ______ or _______

90

COLIA 1

COLIA 2

Bone modeling in OI is defective

There is a decrease in:

• cross-sectional area of the long bones

• bone mass

• trabeculae

• strength and support

Does bone volume increase with age?

No

Type I (most common form)

• the mildest form of OI

• bone fractures and muscle weakness

• no bone deformity

Type II

• Most SEVERE

• multiple broken bones in utero during birth → won’t survive birth

Type III

• broken bones at birth

• severe physical disabilities

Type IV

• bones may break easily

• first bone break pre-puberty

• mild to moderate bone deformity

Patient History

• most commonly present with fractures after minor trauma

  • can be mistaken for child abuse prior to diagnosis due to frequency of fractures and bruising of the skin

Symptoms (vary within the severity)

Severe, Mild, general presentation

Severe: growth retardation, long bone/spinal deformities

Mild: occasional fractures when children begin to walk

• shortened stature

• hypermobility of joint (joint laxity)

• hearing impairment

• blue sclera

• pain

Clinical Manifestations

• triangular facies

• macrocephaly (large skull)

• defective dentition

• barrel chest

• scoliosis

• limb deformities

What are visual presentation examples of an individual with OI?

• Genu Varum (bowing of the legs)

• Scoliosis

• Shorter stature

Evaluation techniques

X-rays and films are REQUIRED

**** Be Gentle

What is the main goal of treatment?

Prevent deformities and fractures

Allow them to function as independently as possible

Medication

Bisphosphonates → inhibit bone resorption, facilitate bone formation

Orthotic Bracing

SMO, KAFO, HKAFO

• support weak muscles

• fracture prevention and control

• keep joints properly aligned

When would surgery be an option?

This is the last effort

• telescoping intramedullary rods for long bones

What is a surgical option to manage recurring fractures for patients with OI?

Telescoping intramedullary rods

Bone transplant

Titanium pins and plates

You would never have surgery for this type of fracturing

Telescoping intramedullary rods

What is the pathophysiology of the characteristic blue sclera noted in patients with Osteogenesis imperfecta?

-Abnormal Type II collagen production that results in translucent connective tissue over the choroidal veins in the eyes
-Decreased elastin production that when combined with the collagen matrix, results in a thinner sclera translucent connective tissue over the choroidal veins in the eyes
-Abnormal Type I collagen production that results in translucent connective tissue over the choroidal veins in the eyes
-Decreased fibrin production that when combined with the collagen matrix, results in a thinner sclera translucent connective tissue over the choroidal veins in the eyes

Abnormal Type I collagen production that results in translucent connective tissue over the choroidal veins in the eyes

What forms of OI present with scoliosis, triangular-shaped face, severe osteoporosis and normal sclera?

Types I and III

Type III

Type IV

Type I and IV

Type III

OI is caused by a mutation of this protein in the body?

Keratin

Actin

Collagen

Elastin

Collagen

OI is a/an _____________ disease?

Congenital

Contagious

Infectious

Environmental

Congenital