63 Beyond the clinical exam: Assessing the added value of imaging in breech newborns for hip dysplasia screening

Abstract Background Developmental dysplasia of the hip (DDH) is the most prevalent neonatal musculoskeletal disorder, affecting 1-4% of all newborns. It can lead to delayed motor development and osteoarthritis, often requiring surgical intervention. A known risk factor for DDH is breech position during gestation; however, up to 50% of infants diagnosed may have normal hips at birth, as hip develops in the initial months of life. The effectiveness of screening methods, especially radiological imaging, remains debated. In 2014, the American Academy of Orthopaedic Surgeons (AAOS) recommended imaging for this at-risk group before 6 months of age. Objectives The study aimed to assess the additional screening value of imaging for detecting DDH in breech newborns compared to clinical examination alone. Design/Methods This retrospective observational study included all infants in breech position during the third trimester born at our tertiary academic center between June 2021 and December 2022. Infants were included if they underwent hip ultrasound at 6 weeks at our center and were prescribed hip radiography at 6 months. Data were collected from medical records, including demographic informations, physical examination findings, imaging results, and treatment details. This study was approved by the local ethics committee. Results A total of 518 patients were included in the study, categorized as follows: breech (n=374), transverse (n=13), and cephalic with a history of third-trimester breech positioning (n=131). Among these, 405 (78%) were term births, and 113 (22%) were preterm (Table 1). Hip radiography was conducted for 394 patients. Screening lead to the identification of 47 cases of suspected DDH: 9 (19.1%) detected through physical examination at birth, 23 (48.9%) by ultrasound at 6 weeks, and 15 (31.9%) via radiography at 6 months. Of the 47 patients referred to paediatric orthopedics, 17 underwent harness treatment: 6 due to abnormal physical examination findings, 8 based on ultrasound results, and 3 from radiographic findings. This resulted in an overall DDH prevalence of 7.3% diagnosed through imaging methods. The number needed to screen (NNS) was 86 for physical examination, 65 for ultrasound, and 131 for radiography. Conclusion Our findings indicate that while physical examination at birth can identify some cases of DDH, supplemental imaging, particularly a 6-week ultrasound, enhances early detection in breech-presenting infants. Given the high number needed to screen with routine 6-month radiography, its standard use may warrant re-evaluation. These results underscore the value of targeted imaging for at-risk populations to optimize timely diagnosis and intervention for DDH.