A 14 year old boy is being evaluated related to his height o…

A 14 year old boy is being evaluated related to his height of 58 inches and weight of 58 pounds.  The physician has recently initiated therapy with doses of somatotropin three times a week.  The physician orders an x-ray of the boy’s femur to be done in six months.  The mother asks why this x-ray is to be taken.  The nurse will explain that it is to evaluate if the: