Is Radiographic Imaging Necessary for Identifying Late Developmental Dysplasia of the Hip in Breech Infants with Normal Ultrasounds?

Purpose. The goal of our study was to investigate the prevalence of late DDH cases in breech infants who had a normal screening hip ultrasound and subsequent follow-up hip x-ray imaging. Methods. Infants with a history of intrauterine breech position, normal hip ultrasound within 3-months of birth, and follow-up hip x-rays within 2-years were included. Acetabular indices were measured on a supine AP pelvis radiograph. Results. Fifty-six patients had breech presentation at birth, a normal hip ultrasound, and returned for radiographic evaluation within 2 years. Of those, 11/112 (10%) of hips had late DDH based on their radiographic images at 1 standard deviation greater than normative values from age-adjusted controls. No infants showed hip dysplasia at 2 standard deviations greater than normative values from age-adjusted controls. Conclusions. Our results support previous studies that follow up should be considered for infants with breech presentation and normal hip ultrasounds near birth. Level of evidence. II.