Updating radiographic parameters for the healthy growing hip: are current parameters still valid?

This study aimed to evaluate whether the acetabular angle (AA) by Tönnis and lateral center-edge angle (LCEA) by Wiberg-key radiographic parameters in pediatric hip assessment-have changed in a contemporary pediatric population compared with historical reference values, considering trends in earlier skeletal maturation and body composition.

This retrospective diagnostic accuracy study assessed changes in AA and center-edge angle (CE) angles in a contemporary cohort. A total of 1774 anteroposterior pelvic radiographs (3548 hips) from patients aged 0-18 years without hip pathology were analyzed. Radiographs were obtained between 2006 and 2018 and measured using the Supervisely digital platform. Standardized anatomical landmarks were applied. Data were stratified by age and sex and compared with historical values using two-sample t-tests (p < 0.05). To minimize measurement bias, two independent observers conducted all assessments using standardized digital protocols.

A total of 1774 patients aged 0-18 years (mean age, 8.30 ± 5.20 years; 666 females, 1108 males) were evaluated. AA values did not show statistically significant differences in 11 of 16 age groups compared with historical data (p > 0.05). In contrast, LCEAs were significantly higher in the contemporary cohort, especially in the 5-8, 9-12, and 12-16 age groups (all p < 0.01), indicating a trend toward earlier or increased acetabular ossification and femoral head coverage.

LCEA values were significantly higher in the contemporary pediatric cohort compared with historical data, while AA values remained stable across most age groups. These findings suggest that current radiographic reference standards for LCEA may warrant reassessment to ensure accurate dysplasia assessment.

level 3 (diagnosis).