to toha omegamd - yazdoc

[ArchivalUser]

i am getting confused in Bone age and chronological age stuff of growth charts
can u explain

[ArchivalUser]

really simple.....just like height and weight we use bone age (x-ray) vs. chronological age(age in years) to assess how fast or slow a kid is growing against the mean. What is the mean? Someone with nothing to do looked at a gazzillion (exaggeration!) x-rays of kids of various ages and did a bell curve. They then figured out the mean for each age and the standard deviations from the mean. They published the numbers and charts to make us miserable on the USMLE and themselves rich beyond belief!! As physicians we are expected to use these charts be comparing the x-ray of the wrist or hand of the child in our office to the x-ray on the chart(age appropriate). Like this we can tell if the kid is growing too fast, too slow, or just right.

[ArchivalUser]

chronological age: is the usual people age we use, how may years some one has lived, say a boy is 16 yrs old.
bone age: reflects the different shapes of the epiphysial line that normally matched to the chronological age, this epiphysial line completely disappears at puperty by the effect of sex hormones which lead to complete epiphysial fusion, there is an Atlas where the radiologists look for normally matched bone age & chronological age & use it as a referance:
http://img.medscape.com/pi/emed/ckb/pedi...924506.jpg
significance: used maily in short stature assesment, like in constitusional short stature where the bone age lags behind the chronological age, i.e a boy aged 14 yrs, his bone age should be 14 as in the picture, but instead his bone age is 8 yrs "for example", unlike familial short stature where both bone age and chronological age normally matched i.e. chronological age 14 yrs and bone age 14 yrs.
may used also in precocccious puperty where the bone age is advanced than the chronological age, say agirl is 8 yrs old, but her bone age instead of being 8 yrs it is 14 yrs "for example"

[ArchivalUser]

http://img.medscape.com/pi/emed/ckb/pedi...924505.jpg