title: Prevalence of different hip sonographic types: A cross-sectional study.
abstract: BACKGROUND
  Developmental dysplasia of the hip (DDH) is an anatomical abnormality, which needs early detection and treatment. Ultrasound (US) is a sensitive method to study neonatal hip joint and detection of different types of sonographic hip. This study was aimed to determine relative frequency of different types of DDH ultrasonographically.
  
  
  METHODS
  Ultrasound examination was performed on 380 newborns to determine hip joint status according to the Graf ultrasound classification system for infant hips. In addition, hip joint status was compared based on the hip side, gender, and method of delivery.
  
  
  RESULTS
  In this study, we observed three sonographic types: Ia (74%), type Ib (20%), and IIa (6%). No significant difference was found in relative frequency of different types of DDH regarding the side of the hip (P = 0.18). Type IIa was found significantly more in the female newborns (P < 0.0001) and in newborns who were born by cesarean section (P < 0.0001).
  
  
  CONCLUSIONS
  This study supports the role of US detection of different types of DDH; however, the frequency of pathologic types of hip sonography is 6%.
authors.affiliation: Department of Radiology, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Atoosa
authors.initials: A
authors.lastname: Adibi
authors.affiliation: Department of Radiology, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mahdi
authors.initials: M
authors.lastname: Karami
authors.affiliation: Department of Radiology, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Kaveh
authors.initials: K
authors.lastname: Koohi
authors.affiliation: Department of Radiology, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mehran
authors.initials: M
authors.lastname: Shirahmad
keywords: Developmental dysplasia of the hip; Hip dislocation; hip dysplasia; ultrasonography