title: CT-based morphological assessment of the hip joint in Japanese patients: association with radiographic predictors of femoroacetabular impingement.
abstract: OBJECTIVE
  Femoroacetabular impingement (FAI) has been highlighted and well documented primarily in Western countries and there are few large studies focused on FAI-related morphological assessment in Asian patients. We chose to investigate this subject.
  
  
  METHODS
  We assessed the morphology of the hip and the prevalence of radiographic FAI in Japanese patients by measuring predictors of FAI. We reviewed a total of 1178 hips in 695 men and 483 women with a mean age of 58.2 years (20 to 89) using CT images that had been obtained for reasons unrelated to symptoms from the hip. We measured the lateral centre edge angle, acetabular index, crossover sign, alpha angle and anterior femoral head-neck offset ratio.
  
  
  RESULTS
  A total of 441 hips (37.4%) had pincer-type deformity (41.7% men, 31.3% women) and 534 (45.3%) had cam-type deformity (54.4% men, 32.3% women). Moreover, 773 hips (65.6%) had at least one parameter that predisposes to FAI (74.0% men, 53.6% women) and 424 hips (36.0%) had two or more parameters (43.6% men, 25.0% women).
  
  
  CONCLUSIONS
  The prevalence of radiographic FAI was common in Japanese patients who are generally considered to have dysplastic hips. Cite this article: Bone Joint J 2016;98-B:1167-74.
authors: Tokushima University Graduate School, 3-18-15, Kuramoto, Tokushima, 7708503, Japan.
authors: K
authors: K
authors: Mineta
authors: Tokushima University Graduate School, 3-18-15, Kuramoto, Tokushima, 7708503, Japan.
authors: T
authors: T
authors: Goto
authors: Tokushima University Graduate School, 3-18-15, Kuramoto, Tokushima, 7708503, Japan.
authors: K
authors: K
authors: Wada
authors: Tokushima University Graduate School, 3-18-15, Kuramoto, Tokushima, 7708503, Japan.
authors: Y
authors: Y
authors: Tamaki
authors: Tokushima University Graduate School, 3-18-15, Kuramoto, Tokushima, 7708503, Japan.
authors: D
authors: D
authors: Hamada
authors: Tokushima University Graduate School, 3-18-15, Kuramoto, Tokushima, 7708503, Japan.
authors: I
authors: I
authors: Tonogai
authors: Tokushima University Graduate School, 3-18-15, Kuramoto, Tokushima, 7708503, Japan.
authors: K
authors: K
authors: Higashino
authors: Tokushima University Graduate School, 3-18-15, Kuramoto, Tokushima, 7708503, Japan.
authors: K
authors: K
authors: Sairyo
mesh_terms: D000077:Acetabulum / Q000002:abnormalities; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D057925:Femoracetabular Impingement / Q000175:diagnosis* / Q000453:epidemiology*; D005270:Femur Head / Q000002:abnormalities; D006617:Hip Dislocation / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D021621:Imaging, Three-Dimensional; D007564:Japan / Q000453:epidemiology; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D015995:Prevalence; D016059:Range of Motion, Articular / Q000502:physiology; D012189:Retrospective Studies; D012720:Severity of Illness Index; D017678:Sex Distribution; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
keywords: Computed tomography; Femoroacetabular impingement; Hip morphology