Mod 3-2 Osteogenesis Imperfecta Flashcards
Osteogenesis Imperfecta (OI) is a disease of the ______ ______.
connective tissue
What type of tissue is affected in OI?
bone
What is another name for OI?
Brittle bones disease
What is the definition of OI?
Inherited generalized disorder of connective tissue characterized by multiple fractures and an unusual blue color of the sclera (white) of the eye.
What are the two ways OI may develop?
As an inheritable disease or a mutation
What are the two distinctive characteristics of OI?
*Both inherited and mutation
Fragile bones and blue sclera
What is collagen?
Foundation of the bones
What is the etiology of OI?
Failure in collagen synthesis and structure, not produced correctly early in fetal life.
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.
collagen; bones
What are the two classifications of OI based on older research?
- 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.
Newer research has shown that there are though to be __ classifications of OI. And what are their classification designations?
4; New classifications are types I through IV
*Also several sub-classifications of the disease
List affected sites of OI.
Skeleton, eyes, teeth, skin
*These sites are affected because their collagen formulation is similar in some manner.
Which type of OI often is NOT diagnosed at birth?
Type 1, OI Tarda
Why is Type 1 OI often not seen at birth?
They are relatively normal in birth weight and length, which is not true with more severely affected children.
Which type of OI has a bluing of the sclera?
Type 1 OI Tarda
By what age may kyphosis and scoliosis become apparent?
By 10 years
When may some degree of hearing loss develop? Why?
In the late teens or early 20’s because the ossicles (small bones in the middle ear) are fragile or malformed in some manner.
What form of OI is referred to the congenita form?
Type II
Which form is readily noticed at birth and babies usually do not survive?
Type II OI Congenita form
Some type ___ OI babies have fractures in utero and the fractures tend to increase in number during childhood.
Type I, Tarda form
What are some characteristics of type II OI (congenita form)?
- Readily noticed at birth
- Babies usually do not survive
- Many deformities of the ribs, vertebrae and bones
- Innumerable fractures
- Low birth weight and length
What is type III OI referred to as?
Progressively deforming
Compared to types I and II, what is the severity of type III OI?
Type III is more severe than type I but less severe than type II.
What type of OI often have fractures in utero, but they do not die from this form of OI?
Type III progressively deforming
Which OI has multiple fractures as they get older that result in progressive twisting and bowing deformities of long bones?
Type III progressively deforming
*both upper and lower extremities involved
How does the sclera appear in a child with type III OI?
May be white or blue at birth, but the color will become normal in late infancy.
Kyphosis or scoliosis may be present in this type of OI, but if hearing loss is present it tends to be more severe.
Type III
What is the most rarest type of OI?
Type IV
Which OI type is type IV very similar to and what is the difference?
Type I; the sclerae are not blue in type IV
What are the characteristics of type IV OI?
Varying degrees of hearing impairment and varying degrees of osteoporosis and fractures.
Which OI type tends to reoccur in women after menopause?
Type IV
List facts of fractures for type I OI, Tarda form.
- Average 20-40 fractures before puberty
- Fewer fractures after puberty
List facts of fractures for type II OI, convenita form.
Fractures before birth
List facts of fractures for type III OI, progressively deforming type.
- 20+ fractures by 3 years old
- Up to 100 fractures by puberty
*Short stature, bone deformities
List facts of fractures for type IV OI.
- Most fractures occur in childhood
- May be some fractures at birth
- Reoccurs in women after menopause
*Mildly short stature
What are some radiographic manifestations of OI?
- 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
What is the effect of OI on radiographic technique?
This varies. Increase technique for healing fractures or decrease due to osteoporosis.
What should you do to the KVP where there are large amounts of callus at a healing fracture site?
Add kVp
What should you do to the kVp for survey studies with osteoporosis?
Drop kVp 10%
