Article
Bone Age
Bone age is an assessment of skeletal maturation usually determined by radiographic comparison of the left hand and wrist to standard atlases (Greulich & Pyle) or scoring systems (Tanner–Whitehouse).
Purpose
- Evaluate advanced or delayed maturation relative to chronological age.
- Distinguish constitutional delay from pathologic causes of short stature or pubertal delay.
- Predict remaining growth potential and adult height (Bayley-Pinneau or other prediction methods).
Pubertal Context
During puberty, bone age often advances faster than chronological age as estradiol accelerates epiphyseal maturation. Early estrogen exposure (precocious puberty) leads to disproportionately advanced bone age → reduced final stature if untreated.
Interpretation
- Advanced Bone Age: >2 SD above mean; consider precocious puberty, hyperthyroidism, obesity, congenital adrenal hyperplasia.
- Delayed Bone Age: >2 SD below mean; consider constitutional delay, chronic illness, malnutrition, hypothyroidism, hypogonadism.
Limitations
- Inter-reader variability; digital automated methods reduce variance.
- Atlas standards may not perfectly match diverse contemporary populations.