Ch 20 Part 1

Question 1

Osteonecrosis

Answer 1

bone death; avascular necrosis due to trauma

Question 2

Osteomyelitis

Answer 2

bone marrow infection

Question 3

Dysostosis

Answer 3

developmental anomaly of bone

Question 4

Homeobox gene

Answer 4

structural development during embryonic development (tends to be regionalized)

Question 5

Klippel-Feil Syndrome

Answer 5

Failure of cervical vertebrae to develop into 7 vertebrae

idiopathic congential fusion of any two cervical vertebrae

Question 6

What is the name of the deformity that is often associated with Klippel-Feil Syndrome?

Answer 6

Sprengel’s deformtity

Question 7

What is sprengel’s deformity?

Answer 7

fusion of scapula to the transverse process

Question 8

What are some other associated findings with dysostosis?

Answer 8

Aplasia, supernumerary digits, and abnormal fusion of bones

Question 9

What is aplasia?

Answer 9

absent or incomplete development with abnormal function

Question 10

In association with dysostosis, where does abnormal fusion of bones usually occur?

Answer 10

usually in the digits

Question 11

Dysplasia

Answer 11

mutations interfere with growth or homestasis (dwarfism)

Question 12

Dysplasia of bone is termed?

Answer 12

osteodysplasia

Question 13

Dysplasia of cartilage is termed?

Answer 13

chondrodysplasia

Question 14

Osteogenesis Imperfecta is also called

Answer 14

Brittle bone disease

Question 15

What type of collagen is mutated by Osteogenesis Imperfecta?

Answer 15

Type I

Question 16

What chains of type I collagen are mutated in Osteogenesis Imperfecta?

Answer 16

Alpha 1 and Alpha 2 chains

Question 17

What happens to the abnormal collagen suffering from Osteogensis Imperfecta?

Answer 17

it leads to premature breakdown

Question 18

Is Osteogenesis Imperfecta autosomal recessive or dominant?

Answer 18

autosomal dominant

Question 19

What structres are typically affected by Osteogenesis Imperfecta?

Answer 19

bones, eyes, teeth, inner ear bones (often leads to deafness), skin, and joints

Question 20

What type of Osetogenesis Imperfecta is lethal in utero?

Answer 20

Type II

Question 21

When is Type I Osteogenesis Imperfecta diagnosed?

Answer 21

in childhood

Question 22

What are some common features associated with Type I O.I.?

Answer 22

fractures, etremeity bowing, scoliosis, ligamentous laxity, hearing loss, short stature

Question 23

What is Zebra Stripe Sign?

Answer 23

it is associated with children who have Type I O.I. who have been treated with bisphosphonates and appears on X-ray in a zebra stripe fashion

Question 24

What is the most common form of dwarfism?

Answer 24

Achondroplasia

Question 25

A decrease in growth plate expansion is referred to as

Answer 25

Achondroplasia

Question 26

What mutation leads to achondroplasia?

Answer 26

Fibroblast growth factor receptor (FGFR3)

Question 27

What does the mutation of FGFR3 cause?

Answer 27

decreased cartilage synthesis and inhibited epiphyseal chondrocytes

Question 28

About what percentage of Achondroplasia is caused by an autosomal dominant mutation of FGFR3?

Answer 28

25%

Question 29

List some physical features associated with achondroplasia

Answer 29

short proxial extremities, lower extremity bowing, frontal bossing, midface hypoplasia

Question 30

To be considered a dwarf, you must be this height or shorter?

Answer 30

4'10" (147cm)

Question 31

Describe the spinal features of Achondroplasia

Answer 31

bullet vertebrae, hyperlordosis or kyphosis at birth, scoliosis, and spinal stenosis

Question 32

What parts of the vertebral column become stenotic with achondroplasia?

Answer 32

foramen magnum and spinal canal

Question 33

What can spinal stenosis of achondroplasia lead to?

Answer 33

possible brain compression or cardiovascular abnormalities (may be lethal)

Question 34

Describe Thanatophoric dwarfism?

Answer 34

Fatal: extremely small thorax and short long bones perinatal respiratory failure

Question 35

What else can OsteoPETROSIS be called?

Answer 35

marble bone disease or Albers-Schonberg disease

Question 36

What is the main identifier of Osteopetrosis?

Answer 36

decreased osteoclast-mediated bone resoprtion In other words, excessive over-mineralization of bone leads to brittleness

Question 37

What is the other main feature of osteopetrosis?

Answer 37

skeletal sclerosis ("stone-like" bone) which leads to increases in fractures

Question 38

Foraminal stenosis of ostepetrosis can lead to?

Answer 38

cranial nerve palsies

Question 39

What does the medullary cavity fill with in osteopetrosis?

Answer 39

deranged hematopoiesis

Question 40

What can deranged hematopoiesis of osteopetrosis lead to?

Answer 40

hepatosplenomegaly, recurrent infections, and anemia

Question 41

What is the treatment for osteopetrosis?

Answer 41

stem cell replacement

Question 42

List some typical X-ray features associated with osteopetrosis?

Answer 42

bright white appearance due to overly dense bone, lacking medulla in long bones, and Erlenmeyer flask deformity

Question 43

What do fractures of osteopetrosis look like on X-ray?

Answer 43

"chalk-stick fracture"

Question 44

What type of bone is most impacted by osteoporosis?

Answer 44

trabecular bone (cancelous spongy)

Question 45

What are some common bones affected by osteoporosis?

Answer 45

vertebral bodies, femoral neck, calcaneus

Question 46

A decrease in bone density leads to an increase in

Answer 46

porosity

Question 47

What T-score determines a major fracture risk?

Answer 47

2.5 SD and above

Question 48

What is primary Senile osteoporosis?

Answer 48

age-related osteoporosis

Question 49

What is the other form of primary osteoporsis?

Answer 49

Postmenopausal

Question 50

A decrease in growth factor equals a decrease in osteoblast ativity, with normal osteoclast activity describes what?

Answer 50

Senile osteoporosis

Question 51

Around what age does bone loss of .5% each year begin?

Answer 51

mid 20's

Question 52

A decrease in estrogens accelerating bone loss describes

Answer 52

Postmenopausal osteoporosis

Question 53

What are the three factors that determine peak bone mass?

Answer 53

physical activity, genetic factors, and nutrition

Question 54

Describe how one may maximize bone desnity in young adulthood.

Answer 54

Diet, regular exercise (resistance training, athletics), Ca+ and Vit. D supplementation

Question 55

List some common risk factors for osteoporosis

Answer 55

Increased age, sedentary lifestyle, family history, malnutrition, and malsbsorption

Question 56

What are some common fractures typically associated with osteoporosis?

Answer 56

vertebral compression fractures,and femoral neck fractures

Question 57

A vertebral compression fracture as a result from osteoporosis in the thoracolumbar region leaves one at risk for

Answer 57

pneumonia

Question 58

A femoral neck fracture as a result of osteoporosis leaves one at risk for

Answer 58

pulmonary emboli

Question 59

What is the preferred method for diagnosing osteoporosis?

Answer 59

DEXA scan, or bone density scan

Question 60

What is the required bone percentage loss to have osteoporosis?

Answer 60

30-40% bone loss

Question 61

List some ways one can prevent osteoporosis

Answer 61

physical activity prior to age 30, Ca+ and Vit. D supplementation, and pharmacological agents

Question 62

Bone in Paget's Disease appears to have a _____ appearance

Answer 62

"shaggy"

Question 63

In short, describe how Paget's disease affects bone

Answer 63

regional osteoclast activity excessive bone formation which leads to disorganized lamellar bone with greater bone mass, but is weakened

Question 64

How is Paget's disease diagnosed?

Answer 64

serum testing to determine if alkaline phosphatase levels are eleavted (byproduct of osteoblast activity)

Question 65

Bone in Paget's disease is said to be in this pattern

Answer 65

mosaic or "jigsaw" pattern

Question 66

In Idiopathic Paget's disease, what antigens are attached on osteoclasts?

Answer 66

Paramyxoviridae

Question 67

What percentage of Idiopathic Paget's diease is asymptomatic?

Answer 67

70-90%

Question 68

How is Idiopathic Paget's Disease diagnosed?

Answer 68

through incidental X-ray findings

Question 69

What is the MC (most common) feature of Idiotpathic Paget's disease?

Answer 69

neck and back pain

Question 70

What is an "ivory vertebra sign"?

Answer 70

On x-ray findings a vertebral body appears very white in comparison to the others

Question 71

What three ailments is an "ivory vertebra sign" indicative of?

Answer 71

Paget's disease, metastatic cancer, and lymphoma