The assessment of the efficacy of radiography in diagnosing developmental dysplasia of the hip in infants younger than six months with reference to hips graded by Graf classification using ultrasonography.

OBJECTIVE: This study aims to evaluate the diagnostic effectiveness of radiography for developmental dysplasia of the hip (DDH) in infants being younger than six months by comparing the results with hips graded by Graf classification using ultrasonography (US). While US is standard for screening and diagnosing DDH in this age group, radiography may provide broader insights for screening programs and boost diagnostic precision.

PATIENTS AND METHODS: This retrospective research involved 994 hips from 497 newborns and infants under six months old who underwent hip US and radiography for DDH screening from August 2020 to September 2021. Radiographs were reassessed by an experienced pediatric orthopedic surgeon to identify DDH indications. Hips were graded using the Graf classification, and the primary outcome was the diagnostic accuracy of pelvic/hip radiography for DDH, using the US Graf classification as a reference.

RESULTS: Among the 994 hips assessed, 71 (14.3%) right and 51 (10.3%) left hips showed radiograph signs of DDH. Graf grades IIa to IV were found in the radiographs of 43 (8.7%) right and 47 (9.5%) left hips, which accurately diagnosed right- and left-sided DDH with a specificity of 87.0% and 92.4% respectively. Graf grades IIb to IV appeared in the radiographs of 7 (1.4%) right and 14 (2.8%) left hips, diagnosing right- and left-sided DDH with a specificity of 86.1% and 91.1%, respectively.

CONCLUSIONS: Our study results imply that radiographs may be limited in their diagnostic capacity for DDH in newborns and infants during the first six months of life.