What is a normal bone age on a hand‑wrist radiograph for a 14‑year‑old?

Normal Bone Age on Hand-Wrist Radiograph for a 14-Year-Old

For a 14-year-old, normal bone age on hand-wrist radiograph should approximate chronological age (14 years ± 1 year), though significant variation exists based on sex, ethnicity, and pubertal stage. 1, 2

Sex-Specific Expectations

Girls:

• At age 14, bone age typically ranges from 13 to 15 years using Greulich-Pyle standards 2
• Peak height velocity occurs during Tanner stages 2-3 (mid-puberty), which typically precedes age 14 3
• By age 14, most girls are in late puberty with advanced skeletal maturation 1

Boys:

• At age 14, bone age typically ranges from 13 to 15 years, though boys may show slightly delayed skeletal maturation compared to girls 2
• Boys with testicular volume <4 ml at age 14 should be referred to pediatric endocrinology for delayed puberty evaluation 4, 1
• Male puberty typically begins after age 9, with peak pubertal changes between ages 12-16 1

Ethnic Variations to Consider

The Greulich-Pyle atlas (derived from white children in 1931-1942) shows systematic differences across ethnic groups that must be considered when interpreting bone age 2:

• Black adolescents: Bone age exceeds chronological age by approximately 10 months in girls and 5 months in boys at age 14 2
• Hispanic adolescents: Bone age exceeds chronological age by approximately 9 months in girls and 11.5 months in boys 2
• Asian adolescents: Bone age exceeds chronological age by approximately 9 months in boys; girls show minimal discrepancy 2
• White adolescents: Girls show bone age exceeding chronological age by approximately 4 months; boys show minimal discrepancy 2

Clinical Interpretation Framework

Assessment of left wrist epiphysis opening on radiography is the standard approach for assessing growth potential. 4, 1

The Tanner-Whitehouse Mark II method can be used to estimate expected adult height using bone age and current height 4. However, recognize that:

• Individual variation within populations is substantial, with 95% prediction intervals for chronological age from a given bone age typically spanning approximately 4 years 5
• Mean differences between bone age and chronological age rarely exceed 1 year in most studies, but between-study heterogeneity is large 5
• Bone age assessment is most accurate when correlated with pubertal stage (Tanner staging) rather than chronological age alone 1, 6

Common Pitfalls to Avoid

• Do not rely solely on bone age without clinical context: Bone age must be interpreted alongside pubertal status, growth velocity, and clinical presentation 6
• Do not apply Greulich-Pyle standards without ethnic adjustment: Failure to account for ethnic variations can lead to misinterpretation, particularly in Black, Hispanic, and Asian adolescents where discrepancies of 9-11 months are common 2
• Do not overemphasize bone age in pathologic conditions: Adult height predictions based on bone age do not apply to children with endocrine or bone pathologies affecting growth 6
• Ensure minimum 6-month observation period: Growth velocity assessment requires at least 6 months to accurately determine appropriate pubertal growth progression 1

When to Pursue Further Evaluation

Bone age significantly advanced (>2 years) or delayed (>2 years) from chronological age warrants endocrinologic evaluation for 7, 6:

• Growth hormone excess or deficiency
• Precocious or delayed puberty
• Thyroid disorders
• Genetic syndromes affecting growth