title: A new measurement method in Graf technique: prediction of future acetabular development is possible in physiologically immature hips.
abstract: BACKGROUND
  Universal ultrasound screening has led to overtreatment and higher follow-up rates than are found with clinical examination alone because of high incidence of physiologically immature hips (type IIa) in the first weeks of life. The ability to predict future acetabular development in physiologically immature hips (type IIa) would therefore help to reduce overtreatment and unnecessary follow-up.
  
  
  METHODS
  We described the γ-angle to assess the femoral head coverage by the acetabular roof, which is measured between the baseline defined by Graf and the cartilaginous edge line connecting the inferior point of the iliac bone (lower limb) to the medial corner of the acetabular labrum. We retrospectively analyzed ultrasonographic findings of infants with developmental dysplasia of the hip diagnosed in our hospital and infants with normal hips screened in our hospital. Group 1 (35 hips) consists of type IIa hips at initial examination and went on to develop into dysplastic hips at follow-up. Group 2 (279 hips) consists of type IIa hips at initial examination and went on to develop into normal hips (type I) at follow-up.
  
  
  RESULTS
  The γ-angles of type IIa hips that developed into type I hip at follow-up ranged between 77 and 82. The γ-angles of type IIa hips that developed into hip dysplasia ranged between 72 and 78. All type IIa hips that had γ-angles >78 degrees developed into normal hips. We also observed that all type IIa hips that had γ-angles <77 degrees developed into dysplasia.
  
  
  CONCLUSIONS
  The amount of cartilage mass covering the femoral head, which is a part of the acetabular roof, can therefore provide information about future acetabular development. This paper describes a new method of measurement (the γ-angle) that assesses the extent of the cartilage coverage of the femoral head, which can predict acetabular development. Its use would decrease the rates of unnecessary follow-up and treatment.
  
  
  METHODS
  Level II (development of diagnostic criteria on the basis of consecutive patients).
authors.affiliation: *Fatih University Faculty of Medicine, Ankara, Turkey †Prishtine American Hospital, Pristine, Kosovo ‡Emsey Hospital, Istanbul §Koru Hospital, Ankara, Turkey.
authors.forename: Osman Y
authors.initials: OY
authors.lastname: Yavuz
authors.forename: Ismail
authors.initials: I
authors.lastname: Uras
authors.forename: Bulent A
authors.initials: BA
authors.lastname: Tasbas
authors.forename: Mustafa H
authors.initials: MH
authors.lastname: Ozdemir
authors.forename: Mustafa
authors.initials: M
authors.lastname: Kaya
authors.forename: Mahmut
authors.initials: M
authors.lastname: Komurcu
mesh_terms: D000077:Acetabulum / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000254:growth & development*; D002358:Cartilage, Articular / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D005260:Female; D005270:Femur Head / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D006618:Hip Dislocation, Congenital / Q000000981:diagnostic imaging* / Q000473:pathology; D006621:Hip Joint / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D006801:Humans; D007223:Infant; D008297:Male; D012189:Retrospective Studies; D014463:Ultrasonography