Impact of Multiple Factors on the Incidence of Developmental Dysplasia of the Hip: Risk Assessment Tool.

Background and Objectives: Developmental dysplasia of the hip (DDH) is one of the most common musculoskeletal conditions in children. If not treated, it leads to disability, gait abnormalities, limb shortening, and chronic pain. Our study aims to determine the impact of multiple risk factors on the incidence of DDH and to develop an interactive risk assessment tool. Materials and Methods: We conducted a retrospective cohort study in the Outpatient Clinic for Children of the Medical University of Warsaw Hospital. The Graf classification system was used for universal ultrasonographic screening. In total, 3102 infants met the eligibility criteria. Results: The incidence of DDH in the study group was 4.45%. The incidence of DDH in the Warsaw population, Poland, during the study period was 3.73 to 5.17 (95% CI). According to the multivariate analysis, the risk factors for DDH were birth weight (OR = 2.17 (1.41−3.32)), week of delivery (OR = 1.18 (1.00−1.37)), female sex (OR = 8.16 (4.86−13.71)), breech presentation (OR = 5.92 (3.37−10.40)), physical signs of DDH (25.28 (8.77−72.83)) and positive family history in siblings (5.74 (2.68−12.31)). Our results support the recent hypothesis that preterm infants (<37 weeks) have a lower rate of DDH. Conclusions: A multivariate logistic regression predictive model was used to build the risk calculator. The DDH risk calculator will be evaluated in a prospective validation study.