Mod 3-2 Osteogenesis Imperfecta

Question 1

Osteogenesis Imperfecta (OI) is a disease of the ______ ______.

Answer 1

connective tissue

Question 2

What type of tissue is affected in OI?

Answer 2

bone

Question 3

What is another name for OI?

Answer 3

Brittle bones disease

Question 4

What is the definition of OI?

Answer 4

Inherited generalized disorder of connective tissue characterized by multiple fractures and an unusual blue color of the sclera (white) of the eye.

Question 5

What are the two ways OI may develop?

Answer 5

As an inheritable disease or a mutation

Question 6

What are the two distinctive characteristics of OI?

*Both inherited and mutation

Answer 6

Fragile bones and blue sclera

Question 7

What is collagen?

Answer 7

Foundation of the bones

Question 8

What is the etiology of OI?

Answer 8

Failure in collagen synthesis and structure, not produced correctly early in fetal life.

Question 9

Not only is the formula for bone building wrong as the child develops in utero, but the process that converts the _______ into a form that is normally present in healthy _____ is often wrong as well.

Answer 9

collagen; bones

Question 10

What are the two classifications of OI based on older research?

Answer 10

• Osteogenesis Imperfecta Congenita* - disease is apparent in utero and children often do not survive because the disease is so severe.
• Osteogenesis Imperfecta Tarda* - Not diagnosed at birth, but later when fractures develop as a result of minor trauma.

Question 11

Newer research has shown that there are though to be __ classifications of OI. And what are their classification designations?

Answer 11

4; New classifications are types I through IV

*Also several sub-classifications of the disease

Question 12

List affected sites of OI.

Answer 12

Skeleton, eyes, teeth, skin

*These sites are affected because their collagen formulation is similar in some manner.

Question 13

Which type of OI often is NOT diagnosed at birth?

Answer 13

Type 1, OI Tarda

Question 14

Why is Type 1 OI often not seen at birth?

Answer 14

They are relatively normal in birth weight and length, which is not true with more severely affected children.

Question 15

Which type of OI has a bluing of the sclera?

Answer 15

Type 1 OI Tarda

Question 16

By what age may kyphosis and scoliosis become apparent?

Answer 16

By 10 years

Question 17

When may some degree of hearing loss develop? Why?

Answer 17

In the late teens or early 20’s because the ossicles (small bones in the middle ear) are fragile or malformed in some manner.

Question 18

What form of OI is referred to the congenita form?

Answer 18

Type II

Question 19

Which form is readily noticed at birth and babies usually do not survive?

Answer 19

Type II OI Congenita form

Question 20

Some type ___ OI babies have fractures in utero and the fractures tend to increase in number during childhood.

Answer 20

Type I, Tarda form

Question 21

What are some characteristics of type II OI (congenita form)?

Answer 21

• Readily noticed at birth
• Babies usually do not survive
• Many deformities of the ribs, vertebrae and bones
• Innumerable fractures
• Low birth weight and length

Question 22

What is type III OI referred to as?

Answer 22

Progressively deforming

Question 23

Compared to types I and II, what is the severity of type III OI?

Answer 23

Type III is more severe than type I but less severe than type II.

Question 24

What type of OI often have fractures in utero, but they do not die from this form of OI?

Answer 24

Type III progressively deforming

Question 25

Which OI has multiple fractures as they get older that result in progressive twisting and bowing deformities of long bones?

Answer 25

Type III progressively deforming

*both upper and lower extremities involved

Question 26

How does the sclera appear in a child with type III OI?

Answer 26

May be white or blue at birth, but the color will become normal in late infancy.

Question 27

Kyphosis or scoliosis may be present in this type of OI, but if hearing loss is present it tends to be more severe.

Answer 27

Type III

Question 28

What is the most rarest type of OI?

Answer 28

Type IV

Question 29

Which OI type is type IV very similar to and what is the difference?

Answer 29

Type I; the sclerae are not blue in type IV

Question 30

What are the characteristics of type IV OI?

Answer 30

Varying degrees of hearing impairment and varying degrees of osteoporosis and fractures.

Question 31

Which OI type tends to reoccur in women after menopause?

Answer 31

Type IV

Question 32

List facts of fractures for type I OI, Tarda form.

Answer 32

• Average 20-40 fractures before puberty
• Fewer fractures after puberty

Question 33

List facts of fractures for type II OI, convenita form.

Answer 33

Fractures before birth

Question 34

List facts of fractures for type III OI, progressively deforming type.

Answer 34

• 20+ fractures by 3 years old
• Up to 100 fractures by puberty

*Short stature, bone deformities

Question 35

List facts of fractures for type IV OI.

Answer 35

• Most fractures occur in childhood
• May be some fractures at birth
• Reoccurs in women after menopause

*Mildly short stature

Question 36

What are some radiographic manifestations of OI?

Answer 36

• Thin, defective cortices
• Often heal with exuberant callus (may appear as malignant bone tumor)
• Rodding is common for support
• Wormian bones and delayed closings of cranial sutures

Question 37

What is the effect of OI on radiographic technique?

Answer 37

This varies. Increase technique for healing fractures or decrease due to osteoporosis.

Question 38

What should you do to the KVP where there are large amounts of callus at a healing fracture site?

Answer 38

Add kVp

Question 39

What should you do to the kVp for survey studies with osteoporosis?

Answer 39

Drop kVp 10%