Prevalence of Developmental Dysplasia of the Hip (DDH) identified through ultrasound screening using the graf method in infants younger than six months at a private hospital

Title : Prevalence of Developmental Dysplasia of the Hip (DDH) identified through ultrasound screening using the graf method in infants younger than six months at a private hospital

Abstract:

Introduction: Developmental Dysplasia of the Hip (DDH) is one of the most common musculoskeletal disorders in infancy. Delayed diagnosis may result in premature osteoarthritis, functional impairment, and the need for complex surgical procedures later in life. Although several risk factors have been described, a considerable proportion of affected infants present without identifiable clinical risk factors, supporting the need for early ultrasound screening.

Objective: To determine the prevalence of DDH using ultrasound screening based on the Graf method in infants younger than six months attending a private hospital and to identify factors associated with the condition.

Methods: An analytical cross-sectional study was conducted in 157 infants aged 2–24 weeks who underwent hip ultrasound screening between June 2024 and December 2025. Only technically adequate ultrasound examinations were included. Demographic, obstetric, clinical, and ultrasonographic variables were analyzed using EpiInfo v7.0 and IBM SPSS v20.0. Continuous variables were compared using the Mann–Whitney U test, while categorical variables were analyzed using the Chi-square or Fisher’s exact test. Odds Ratios (OR) with 95% confidence intervals were calculated, considering statistical significance at p < 0.05.

Results: DDH was identified in 12 infants, corresponding to a prevalence of 7.6%. Most affected hips were classified as Graf type IIa, with spontaneous resolution observed in 83% of cases after four weeks of follow-up. Younger age (4–7 weeks; p = 0.04), family history of DDH (p = 0.003; OR = 7.72), and breech presentation (p = 0.001; OR = 7.55) were significantly associated with DDH. Lower α-angle measurements (55–60°) were also significantly associated with the diagnosis (p = 0.0001). No significant associations were found with sex, birth weight, parity, or mode of delivery.

Conclusions: DDH showed a low prevalence in this population, with most cases corresponding to mild Graf type IIa hips that resolved spontaneously. The associations identified with younger age, family history, breech presentation, and lower α-angle values reinforce the diagnostic value of the Graf method. Furthermore, the presence of DDH in infants without traditional risk factors supports the implementation of universal ultrasound screening programs to facilitate early diagnosis, optimize treatment outcomes, and reduce long-term complications.

Keywords: Developmental Dysplasia of the Hip, Graf Method, Ultrasound Screening, Prevalence, Infants.

Biography:

Frida Gabriela Rocha Gomez is a medical student at the University of Guanajuato, Mexico, with a strong interest in clinical research, pediatric orthopedics, epidemiology, and public health. She has participated as author and co-author in several research projects and has presented her work at national and international scientific meetings, including the VIII Chilean Congress of Public Health and the X Chilean Congress of Epidemiology. Her research has received national awards, and her current work focuses on the early diagnosis of developmental dysplasia of the hip using the Graf ultrasound method.