10-18c Changes to Pediatric Bone & Muscle

Question 1

What factors affect skeletal growth, size, volume, structure, and function of the skeleton?

Answer 1

Growth, size, vol., structure, and function depend upon:
Hormones
Metabolic factors
Nutrition
Mechanical Forces over time
Genetics
Disease or Pathologic processes

growth: m. activation and activity

development and function: bone growth

Question 2

What are the biochemical components of bone growth? What do they contribute to?

Answer 2

Growth Hormone, Insulin-like growth factor: longitudinal bone growth and mass

GH deficiencies: ^BMD

IGF also important for maitenance of BMC in adulthood

puberty and sex hormones: bone growth and development

TH: direct impact on bone metabolism (hypothyroidism = decreased bone lengthening

Question 3

What do sex hormones (estrogens and androgens) lead to at puberty?

Answer 3

rapid longitudinal bone growth, fusion of physis, increased lean body mass, and contribute to significant variability

Question 4

What are the growth factors in the bone? What do they do?

Answer 4

FGF: continually regulate skeletal patterning and bone growth throughout the skeletal growth period

Question 5

What do vitamin D and calcium do?

Answer 5

Vitamin D becomes 125D, which is critical for intestinal absorption of Ca and ionic phosphate

Question 6

What is limiting about Ca?

Answer 6

only 500 mg can be absorbed at one time

Question 7

What measurements are key factors in age, growth, and development?

Answer 7

height, weight, BMI, skeletal maturity and sexual maturity

Question 8

What are the typical growth scales based on?

Answer 8

height, weight, BMI

growth timing and velocity

Question 9

What technique determines skeletal maturity/bone age?

Answer 9

All use left hand and wrist

Atlas technique of Greulich and Pyle: modal maturity indicators described for a specific age

Question 10

What determines bone growth?

Answer 10

stature, growth velocity, timing, mass, and density

Question 11

When do females reach peak height?

Answer 11

15 YO

Question 12

When do females see an increase in growth velocity (height)?

Answer 12

from 9.5 to 10 YO

velocity is ~3.5 in/yr

Question 13

When do males reach peak growth height?

Answer 13

18 YO

Question 14

When do males increase in growth velocity (height)?

Answer 14

11.5 to 13 YO

velocity is ~3.7 in/year

Question 15

When do females see closure of physis?

Answer 15

12.5 to 18 YO

Question 16

When do males see closure of physis?

Answer 16

15-=> 18 YO

Question 17

When do females reach peak bone growth velocity and completion of fusion?

Answer 17

11.5 YO

Question 18

When do males reach peak bone growth velocity?

Answer 18

13.5 YO

Question 19

How does age impact differential diagnosis?

Answer 19

fracture around growth plate differs depending on age due to fusion

onset for fusion is earlier in females

Question 20

How many years after longitudinal growth do females have after first period?

Answer 20

two years

Question 21

What is bone mineral content (mass)?

Answer 21

total bone tissue in an area

measured in grams

Question 22

what is bone mineral density?

Answer 22

amount of bone tissue per volume

measured as g/cm squared or cubed

Question 23

Peak bone mass?

Answer 23

maximal amount of bone tissue following skeletal maturation

Question 24

What measures areal bone mineral density? Units?

Answer 24

DXA (g/cm squared)

Question 25

What measures volumetric density of axial bone?

Answer 25

QCT (g/cm cubed)

Question 26

What measures the bone density and mass for peripheral extremeties?

Answer 26

Peripheral QC

Question 27

What does greater bone mass and density affect?

Answer 27

less likely for fragility fracture

Question 28

What does a Z score act as?

Answer 28

percentile/standard deviation

Question 29

In children 3 to 13 of equivalent weight, what is the diff b/w females and males?

Answer 29

females have greater quad muscles than males

Question 30

What do males have more of at Tanner stage 5?

Answer 30

greater extremity lean soft tissue and total body skeleton m. mass

Question 31

How does muscle strength correlate to factors in males and females aged 4-16? What does this suggest?

Answer 31

males: weight females: weight and age weight related m. reference data

Question 32

at what phase ar females heavier, taller, and stronger?

Answer 32

11-13 yo

Question 33

What ethnicity factors relate to bone density/longitudinal growth?

Answer 33

black children have longer legs and greater cross sectional area

Question 34

What is true about US born children?

Answer 34

heavier and taller

Question 35

How many SD are african american children than caucasian children in bone age? What may this represent?

Answer 35

0.5 SD delayed bone age for african american children advanced bone age for caucasian child

Question 36

What is unique about pediatric skeletons?

Answer 36

preosseus cartilage, growth plates, periosteum (thicker, stronger), more shock absorption (lower BMC)

Question 37

What are pediatric orthopedic concerns?

Answer 37

growth plate injuries (apophysitis), LE deformities, growing pains, pediatric fracture remodeling (better than adults)

Question 38

Why are kids more likely to injure a growth plate than a ligament?

Answer 38

ligaments are attached to the epiphysis and hold on tight, so the force translates down towards the growth plates (less continuous fiber type: multi-segmental)

Question 39

What are the four apophysitis diseases?

Answer 39

Osgood-Schlatter Syndrome:Traction injury due to tendon pulling periostenum away from bone at tibial tuberosity Sinding-larsen-johansonn is the pull on the inferior patella Sever's Disease: Traction apophysitis of the posterior calcaneus Iliac Apophysitis: Traction apophysitis along the iliac crest and/or spine

Question 40

What are growing pains associated with? treatment?

Answer 40

hormonal factors that cause muscle strain during growth; instability at growing junctions massage, hot or cold pack, analgesics

Question 41

What are the major factors for bone remodeling following fracture?

Answer 41

age (younger the better they do), proximity to a joint (physis) the better it remodels, joint axis (deformity in the plane of primary osteokinematic motion) problems: overgrowth, boyonet apposition to compensate

Question 42

What are the requirements for youth resistance training programs?

Answer 42

specifically designed program, supervised setting, proper technique, safety guidelines

Question 43

What are the results to youth training?

Answer 43

significant strength gains, decrease in skinfold measurements, changes in strength likely due to neural components

Question 44

What factors contribute to injury in youth resistance training?

Answer 44

poorly designed programs, poorly supervised programs, excessive load, unqualified supervision, poorly designed equipment, free access to equipment