BIOMED 10/18c Changes to Pediatric Bone Flashcards
what is the issue about pediatric bone?
- patient is still growing
- there are periods of rapid change and variability in regards to
- skeletal maturation
- muscle growth
- sexual maturation
- skill acquisition
growth, size, volume, structure, and function of the skeleton are affected by
- hormones
- metabolic factors
- nutrition
- mechanical forces over time
- genetics
- disease or pathologic processes
hormones that contribute to longitudinal bone growth and mass after birth
- growth hormone - stimulates IGF-1
2. insulin like growth factor-1
importance of GH
deficiencies lead to decreased BMD during childhood
is IGF-1 important for just peds?
NO
it is important for skeletal maturaton and BM acquisition in peds
for adults, it is important for BMC maintenance
Importance of TH
thyroid hormone has a direct impact on bone metabolism
-children with hypothyroidism have decreased bone lengthening
sex hormone impact on pediatric bone growth
- at puberty, estrogens and androgens cause rapid longitudinal bone growth
- lead to fusion of physis and cessation of bone growth
- INCREASED LEAN BODY MASS
- Contribute to significant variability
Growth factors in the bone
Fibroblast Growth Factors
- 23 different FGFs throughout skeletal system
- continually interplay and constantly regulate skeletal muscle
- Examples:
1. periosteum
2. perichhondrium
3. chondrocytes
4. osteoblasts
5. differentiating osteoblasts
6. mesanchyme of sutures of the cranial bone
Importance of Vitamin D**
- Vitamin D3 is produced in the skin following UV light exposure
- metabolized in the liver to 25-hydroxyvitamin D (25D)
- then metabolized in kidney to 1 alpha, dihydroxy vitamin D (125D) - Vitamin 125D plays critical role in intestinal absorption of Ca and ionic phosphate
Significance of Calcium
- Calcium can only be absorbed at 500mg at a time
2. calcium supplementation should be separated out to get the proper amount of dosing
what makes it easier to change diet to absorb calcium than taking the pill?
it is easier because the pill can only be absorbed in doses of around 500mg per sitting. This requires the pt to continually supplement
how is skeletal maturity and bone age determined?
- left hand and wrist were tested
- the atlas technique of greulich and pyle
- tanner whitehouse bone specific scoring
- fels hand wrist method
what is the most common way to determine skeletal maturity/bone age?
Atlas technique of greulich and pyle
-modal maturity indicator
what is the tanner-whitehouse bone specific scoring scale
total bone maturity indicator score up to 1000
typically used in europe
what is the fels hand wrist method to determine skeletal maturity/bone age?
requires software to translate ratings into age
-typically used in North America
typically ____ y/o _____ had their first ____
12.5-13 y/o females had their first period
and this is important for surgery decision making
important aspects of bone growth
- stature
- growth velocity
- timing
- mass
- density
what is the difference between peak height age in males vs females?
females reached at around 15yo while males reached at around 18 yo
females have an early rapid growth velocity than males and they end before males
age comparison of male and female long bone physis closure: onset of closure to complete closure
- age at onset: F = 11-14.5; M = 12-16
- age at completion: F = 12.5-18; M=15->=18
- onset <=13.5: F = 4/6; M = 1/6
sexual maturity’s relationship to bone maturity
girls have around 2 yrs left after their first period for long bone growth
->shows why surgery can be delayed if growth plates aren’t fully developed yet
do you wait for growth plates to develop if pt has SCFE?
No
bone mineral content (mass)
total bone tissue in an area
measured in grams
bone mineral density
amount of bone tissue per volume
either g/cm2 or g/cm3
peak bone mass
maximal amount of bone tissue following skeletal maturation
density and mass measurement
- dual energy x-ray absorptiometry (DXA) - g/cm2
- quantitative computed tomography
- peripheral QCT
- quantitative Ultrasound
- MRI
what is the DXA scan?
areal bone mineral density
- gold standard
- gets the difference between 2 x-ray beams
in peds use __score instead of __score and want to be in the ___ ___
z-score
t-score
standard dev
how does one increase bone mass and density
increased activity at a younger age decreases fracture risk as you age
-greater bone mass and density are associated with decreased fragility fracture
continued increase of bone mass and density following end of height growth is still beneficial to bone healty
in children __ to ___ of equivalent weight, ____ have greater ____ muscle mass than ___ b/c of ____
3 13 females quadriceps males onset of puberty
it is suggested to use ___ related muscle reference data rather than ___ related because of ____ maturation
weight related
age related
sexual maturation
were there differences noted amongst ethnically diverse subjects with tanner groups?
no
significance of growth and isometric strength
- height favors boys at 4
- 10 yo boys are significantly heavier and taller than girls
- 11-13 yo girls are heavier and taller than boys
- 15 yo boys are significantly heavier and taller than girls
black vs white femoral density
black children have longer legs and a significantly greater cross sectional area at midshaft
–greater bone strength in children
–no difference in skeletal age when matched for skeletal maturation
growth variation for US born children vs foreign
US are heavier and taller than foreign born children
what happens to bone age as we age?
it starts to increase more than our actual age!
tw2-tw3 goes into a negative number because of environmental factors, hereditary, dietary, etc
pediatric skeletal difference
Kids bounce after a fall because of more ELASTICITY/SPRINGYNESS of the bone
- preosseous cartialge
- physis: growth plate
- periosteum: thicker, stronger, more osteogenic – faster, bigger callous
- more shock absorption: lower BMC and greater porosity
pediatric orthopedic concerns
- growth plate injuries and conditions
- lower extremity deformities
- growing pains
- pediatric fracture remodelling
structural contributions to physis injury
- occurs prior to ligament injury
- phenomenon decreases with progression toward skeletal maturity/physis closure
- ligaments attach to epiphyses therefore transferring force to the physis
- ligamets are shorter and continuous tissue type (greater tensile strength)
the ____ you are, the ___ likely you are to a joint injury at growth plates
the ___ you are, the ___likely you are to have a ligamentous injury
younger
more
older
more
how do forces typically travel in the body?
horizontally, that leads to growth plate rupture
___are stronger than ____ in children
ligaments
bone
apophysitis dieases in children?
- osgood schlatter
- sinding-larsen-johansonn syndrome
- sever’s disease
- iliac apophysitis
do the apophysitis diseases in children all have the same underlying mechanism?
yes! They are just presented in different parts of the body
they are all because of traction!
osgood schlatter syndrome
traction apophysitis of the tibial tuberosity
- prominent tibial tube
- significant tenderness of the tibial tube
- tendon is pulling the periosteum away from the bone
sindig-larsen-johansson syndrome
traction apophysitis of the inferior pole of the patella
-significant point tenderness to the inferior patella tubercule and proximal patella tendon
Sever’s disease
traction apophysitis of the posterior calcaneus
- pain with shoes, toe walking, running
- outgrowth of bone on lateral order of calcaneus
- posterior calcaneous tenderness
- gastroc/soleus tightness
iliac apophysitis
traction of apophysitis along the iliac crest and/or spine
- TFL
- REctis Femoris
- Sartorius
- Glute Med
- Abdominal Obliques
- track and field athelets and dancers
signs of apophysitis of any of the joints?
- location
- pt will jump when you palpate
- muscle shuts down to compensate (activity decreases)
what is the treatment for apophysitis
stretch the muscle and start to strengthen it
is there evidence confirming growing pains
no conclusive evidence regarding cause
- anecdotally related to:
1. biochemica/hormonal factors
2. muscle strain during growth
3. instability at growing junctions
treatment for growing pains
more for pt comfort
- massage
- hot/cold packs
- analgesics
bone remodeling following fracture
- the younger the child, the better
- the more proximal to the joint/physis the better
- if the fracture is in the same line as the primary axis of motion, the better
what can happen to bone after remodeling when pt is younger than 10 yo
frequently find 1-3 cm overgrowth in long bone due to physeal stimlation during fracture healing
requirements for youth resistance training programs
(pre-pubscent)
- general muscle strengthening ( no targeted body parts)
- supervised settings (less pts to PT)
- proper technique
- SAFETY
pediatric patients must have the following when practicing resistance training
- proper supervision and technique
2. avoid maximum lifint until at least tanner stage 5 (usually 16-17yo)
body composition changes in pediatrics after resistance training
small, if any changes in lean body mass
- minimal muscle hypertrophy
- changes in strength likely due to neural components because of strength gains
- motor unit recruitment
- frequency of motor unit firing
- changes in muscle activation
- changes in contractile properties
Exercise ___ cause growth to be stunted
DOES NOT
what are main factors contributing to pediatric injury during strength training
- poorly designed programs
- poorly supervised programs
- excessive load
- unqualified supervision
- poorly designed equipment
- free access to equipment
