Bone Age in Boys Aged 14 Months — Greulich-Pyle Hand and Wrist X-Ray Reference
Bone age assessment using a left hand and wrist radiograph is a well-established method for evaluating skeletal maturity in children. The Greulich-Pyle (GP) atlas provides standard reference radiographs for comparison, enabling clinicians to identify advancement or delay relative to chronological age. In a 14-month-old boy, this assessment is particularly valuable when investigating failure to thrive, endocrine disorders, or constitutional growth concerns.
Expected Ossification Centers and Skeletal Findings
At 14 months of age in boys, skeletal maturation is still in its early stages. The capitate and hamate are typically the first carpal bones to ossify, appearing around 3 months and 6 months of life respectively, and should be well visualized by this age. The distal radial epiphysis typically appears around 9–12 months in boys and is usually present by 14 months, though its size remains small and rounded at this stage.
The remaining carpal bones are generally not yet ossified at 14 months in boys. The triquetral typically appears between 2–3 years, the lunate between 3–4 years, and the scaphoid, trapezium, and trapezoid between approximately 4–6 years. The pisiform and distal ulnar epiphysis are not expected at this age. Metacarpal and proximal phalangeal epiphyses may be beginning to appear, but are often small or absent at this age in boys.
- Capitate: present (ossifies ~3 months)
- Hamate: present (ossifies ~6 months)
- Distal radial epiphysis: typically present by 14 months
- Triquetral, lunate, scaphoid, trapezium, trapezoid: not yet expected
- Distal ulnar epiphysis: not yet expected
Clinical Pearls
Skeletal maturation in boys typically lags behind girls by approximately 3–6 months at this young age, a difference that widens further during puberty. Normal bone age variation at 14 months spans roughly ±3–4 months around the mean. A bone age significantly advanced beyond chronological age may suggest conditions such as precocious puberty or exogenous androgen exposure, while a notably delayed bone age raises concern for growth hormone deficiency, hypothyroidism, or constitutional delay of growth and puberty. A key pitfall at this age is over-reliance on a single ossification center: the presence or absence of the distal radial epiphysis alone should not drive clinical decisions without integrating the full radiographic picture and clinical context.
Reference: Greulich WW, Pyle SI. Radiographic Atlas of Skeletal Development of the Hand and Wrist. 2nd ed. Stanford University Press, 1959.
