Developmental Dysplasia of the Hip: Factors Related to the Diagnosis and Characteristics of Selective Screening for its Detection.

Abstract

Backgrounds: Breech presentation, family history, and physical examination are the most recognized risk factors for DDH, which form the basis of selective screening. However, this approach can lead to late diagnosis, invasive treatments, and complications. This study analyzes the effectiveness of selective screening and identifies additional factors related to DDH.

Methods: A retrospective case-control analytical study is designed, including children who are assessed through screening between 2012 and 2019. The variables examined include clinical and gestational characteristics, as well as examination findings. Descriptive analysis is conducted, followed by univariate analysis using Chi-squared, Fisher's exact, or Student's T tests. For multivariate analysis, the "all set" user command is employed. Sensitivity, specificity, and ROC curve are calculated, with a significance level set at p < 0.05. StataIC 16 and SAS System 9.4 are used.

Results: 762 children are included in the study, of which 33 are diagnosis with DDH. A total of 8,191 models are developed to predict DDH. The best logistic regression model identified the following independent predictors of dysplasia: newborn weight (OR 1.2, 95% CI 1.1-1.4), female sex (OR 3.9; 95% CI 1.4-10.9), cephalic presentation (OR 17.8; 95% CI 2.3-137.3), primiparity (OR 2.6; 95% CI 1.1-5.7), and examination (OR 149.6; 95% CI 18-1121.4). This model correctly classifies 83.6% patients (ROC curve 0.86). In selective screening, examination is the only identified risk factor for DDH, yet its sensitivity does not exceed 10%.

Conclusions: This study proposed a total of 8191 models to predict DDH. The identified predictors include female sex, birth weight, cephalic presentation, and primiparity. While physical examination is the primary risk factor, it detects only decentred hips. The low sensitivity of selective screening raises questions about whether it remains the most appropriate method for identifying DDH in current practice.