title: Prevalence of developmental dysplasia of the hip in preterm infants with maternal risk factors.
abstract: OBJECTIVE
  The aim of this study was to determine the prevalence of developmental dysplasia of the hip (DDH) in preterm infants with maternal risk factors.
  
  
  METHODS
  A prospective review of the medical records and ultrasound (US) scans of all preterm infants at one tertiary-care children's hospital was completed to identify all premature infants without any infantile risk factors at a particular time frame. We consecutively evaluated 421 babies (842 hips) who satisfied the criteria for inclusion. Hip US images were classified according to Graf.
  
  
  RESULTS
  Overall, one hip was diagnosed as DDH (Graf type 2c). Female infants had significantly lower alpha angles (70.2 ± 6.6 and 71.4 ± 4.4 for females and males, respectively) (P = 0.033). There was no correlation between oligohydramnios and alpha and beta angles and hip sides (P = 0.345 and P = 0.789 for left and right hips, respectively). US examination of the infants revealed no differences between the alpha and beta angles of the hips and birth weight and age at gestation. Although it was statistically not significant, US evaluation of left hips among singletons demonstrated one immature hip (P = 0.864) and that of right hips demonstrated one immature hip for both singletons and twins (P = 0.904).
  
  
  CONCLUSIONS
  Prematurity with or without maternal risk factors does not have an effect on DDH.
authors.affiliation: Departments of Orthopaedics and Traumatology, Diskapi Yildirim Beyazit Education and Research Hospital, Ankara, Turkey.
authors.forename: Cenk
authors.initials: C
authors.lastname: Sezer
authors.affiliation: Departments of Orthopaedics and Traumatology, Diskapi Yildirim Beyazit Education and Research Hospital, Ankara, Turkey.
authors.forename: Serhan
authors.initials: S
authors.lastname: Unlu
authors.affiliation: Departments of Orthopaedics and Traumatology, Kecioren Education and Research Hospital, Ankara, Turkey.
authors.forename: Ismail
authors.initials: I
authors.lastname: Demirkale
authors.affiliation: Departments of Orthopaedics and Traumatology, Diskapi Yildirim Beyazit Education and Research Hospital, Ankara, Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Altay
authors.affiliation: Departments of Orthopaedics and Traumatology, Ataturk Education and Research Hospital, Ankara, Turkey.
authors.forename: Safa
authors.initials: S
authors.lastname: Kapicioglu
authors.affiliation: Departments of Orthopaedics and Traumatology, Yildirim Beyazit University School of Medicine, Ankara, Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Bozkurt
keywords: Developmental hip dysplasia; Maternal; Prematurity; Prevalence; Risk factors