Refining Risk Factors for Developmental Dysplasia of the Hip in Neonates: A Cross-Sectional Study in a Tertiary Referral Center.

Background: Developmental dysplasia of the hip (DDH) is used to describe a spectrum of structural abnormalities that involve the growing hip. Early diagnosis and treatment are critical to providing the best possible functional outcome. This study aimed to evaluate the prevalence of DDH in neonates with and without risk factors and determine the role of ultrasound screening on the initial diagnosis.

Methods: This prospective cross-sectional study was conducted on 399 infants at the Pediatric Treatment Center, Tehran University of Medical Sciences, between December 2015 and June 2016. Infants with suspected DDH who underwent hip ultrasonography were included, and the presence or absence of each risk factor was documented according to the checklist. The ultrasound findings were also registered in the checklists. The odds ratio (OR) of each risk factor for DDH was calculated. The collected data were analyzed by SPSS software version 18 at a 0.05 significance level.

Results: In 16 months of study, 174 (43.6%) male and 225 (56.4%) female infants under the age of 18 months were studied. Risk factors were detected in the medical history of 329 infants. Out of them, 230(57.6%) were firstborn children, 7 (1.75%) had a positive family history of DDH, and 26 (6.5%) had limb anomalies. There was also a history of breech presentation in 16 (4.01%) and a history of oligohydramnios in 21 (5.1%) of infants. The prevalence of DDH was 25.8% in infants with risk factors and 2.8% in those without risk factors. (OR = 11.84, P < 0.05).

Conclusion: In this study, the frequency of DDH was significantly higher in infants with risk factors. The female gender and limb anomalies were stronger risk factors for DDH. Overall, ultrasound showed great potential for DDH screening.