Bone Age in Girls Aged 3 Years — Greulich-Pyle Hand and Wrist X-Ray Reference
Bone age assessment using a left hand and wrist radiograph is a fundamental tool in pediatric radiology for evaluating skeletal maturity relative to chronological age. The Greulich-Pyle method compares the patient’s radiograph to standard atlas plates representing average maturation at each age and sex. Clinically, bone age is used to investigate growth disorders, precocious or delayed puberty, endocrine dysfunction, and, in certain contexts, forensic age estimation.
Expected Ossification Centers and Skeletal Findings
At 3 years of age in girls, several carpal ossification centers are typically well established. The capitate and hamate are among the earliest to appear (around 3 and 6 months, respectively) and should be clearly visible and growing in size by this age. The triquetral ossification center, which typically emerges between 2 and 3 years, is generally expected to be present or just appearing at this age in girls. The lunate center, which usually ossifies between 3 and 4 years, may be visible or just emerging at this stage.
The distal radial epiphysis, appearing around 1 year of age, should be well defined by 3 years. The distal ulnar epiphysis is not yet expected at this age, as it typically appears between 5 and 7 years. The scaphoid, trapezium, and trapezoid ossification centers are generally not yet present, as they typically appear between 4 and 6 years. The pisiform and thumb sesamoid are not expected at this age.
- Capitate: present and well ossified
- Hamate: present and well ossified
- Triquetral: typically present by 3 years in girls
- Lunate: may be just appearing at this age
- Distal radial epiphysis: present and well defined
- Distal ulnar epiphysis, scaphoid, trapezium, trapezoid, pisiform: not yet expected
Clinical Pearls
Skeletal maturation in girls is consistently ahead of boys by approximately 6 to 12 months at this age, a difference that widens during the pubertal years. Normal bone age variation at 3 years spans roughly ±1 year around the chronological age. A bone age significantly advanced beyond 3 years in a girl may prompt evaluation for precocious puberty or exogenous androgen/estrogen exposure, while a notably delayed bone age raises concern for growth hormone deficiency, hypothyroidism, or constitutional delay of growth and development. A key interpretive pitfall is relying solely on the number of ossification centers present without accounting for their size and morphology, both of which contribute to the overall skeletal maturity score.
Reference: Greulich WW, Pyle SI. Radiographic Atlas of Skeletal Development of the Hand and Wrist. 2nd ed. Stanford University Press, 1959.
