The applicability of the Greulich & Pyle Atlas for bone age assessment in primary school-going children of Karachi, Pakistan

Objective: To assess the degree of applicability of bone age calculated by Greulich & Pyle Atlas in estimation of chronological age for therapeutic and medico legal purposes. Methods: Two Hundred and Twenty children (139 males, 81 females) between ages of 56 and 113 months (4.5 to 9.5 years) were randomly selected from 4 primary schools of Shireen Jinnah & Clifton, Karachi. Digital images of hand and wrist radiographs were obtained by a computed radiography at Ziauddin Hospital Clifton. Bone ages were computed using Greulich & Pyle Atlas by radiologists at Ziauddin Hospital, North Nazimabad, Karachi. Results: On average, the Greulich & Pyle Atlas underestimates chronological age by 6.65 ± 13.47 months in females and 15.78 ± 12.83 months in males (p-values < 0.001). High correlation was found between chronological age and bone age in both genders (Females r=0.778; p-value< 0.001, Males r=0.816; p-value < 0.001). Conclusion: Bone age calculated by Greulich & Pyle Atlas should not be used for estimating chronological age in children of ages 56-113 months in situations where high accuracy is required (e.g. medicolegal cases). However, serial measurements of bone age by this atlas can be used in management of growth related endocrine disorders in these children.