title: What is the Prevalence of Radiographic Hip Findings Associated With Femoroacetabular Impingement in Asymptomatic Asian Volunteers?
abstract: BACKGROUND
  Morphologic features of the proximal femur reminiscent of those seen in patients with femoroacetabular impingement (FAI) have been reported among asymptomatic individuals in Western populations, but whether this is the case in Asian populations is unknown.
  
  
  OBJECTIVE
  The purpose of this study was to determine the prevalence of radiographic findings in the proximal femur that are consistent with FAI in asymptomatic Korean volunteers.
  
  
  METHODS
  Two hundred asymptomatic volunteers with no prior hip surgery or childhood hip problems underwent three-view plain radiographs (pelvis AP view, Sugioka view, and 45° Dunn view) of both hips. There were 146 hips from male volunteers and 254 hips from female volunteers in the study. The mean age of all participants was 34.7 years (range, 21-49 years). Cam-type morphologic features were defined as the presence of the following on one or more of the three views: pistol-grip morphologic features, an osseous bump at the femoral head-neck junction, flattening of the femoral head-neck offset, or alpha angle greater than 55°. Pincer-type morphologic features were determined by radiographic signs, including crossover sign, deficient posterior wall sign, or lateral center-edge angle greater than 40°.
  
  
  RESULTS
  The prevalence of cam-type morphologic features seen on at least one radiograph was 38% (male, 57%; female, 26%). The prevalence of cam-type features (at least one positive cam-type feature) was 2.0% (male, 6%; female, 0%) on the pelvic AP view, 24% (male, 36%; female, 17%) on the Sugioka view, and 30% (male, 47%; female, 20%) on the 45° Dunn view. The prevalence of pincer-type morphologic features (at least one positive pincer-type feature) was 23% (male, 27%; female, 21%) on the pelvic AP view.
  
  
  CONCLUSIONS
  The prevalence of FAI-related morphologic features in asymptomatic Asian populations was comparable to the prevalence in Western populations. Considering the high prevalence of radiographic hip findings reminiscent of FAI in asymptomatic Asian populations, it will be important to determine whether FAI-related morphologic features are a cause of hip pain when considering surgery in Asian patients.
authors: Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro, 43-gil, Songpa-gu, Seoul, 05505, South Korea.
authors: Taesoo
authors: T
authors: Ahn
authors: Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro, 43-gil, Songpa-gu, Seoul, 05505, South Korea.
authors: Chul-Ho
authors: CH
authors: Kim
authors: Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro, 43-gil, Songpa-gu, Seoul, 05505, South Korea.
authors: Tae Hyung
authors: TH
authors: Kim
authors: Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro, 43-gil, Songpa-gu, Seoul, 05505, South Korea.
authors: Jae Suk
authors: JS
authors: Chang
authors: Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro, 43-gil, Songpa-gu, Seoul, 05505, South Korea.
authors: Mi Yeon
authors: MY
authors: Jeong
authors: Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro, 43-gil, Songpa-gu, Seoul, 05505, South Korea.
authors: Kekatpure
authors: K
authors: Aditya
authors: Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro, 43-gil, Songpa-gu, Seoul, 05505, South Korea. orthoyoon@amc.seoul.kr.
authors: Pil Whan
authors: http://orcid.org/0000-0001-7354-0989
authors: PW
authors: Yoon
mesh_terms: D000328:Adult; D044466:Asian People; D058070:Asymptomatic Diseases; D001696:Biomechanical Phenomena; D005260:Female; D057925:Femoracetabular Impingement / Q000000981:diagnostic imaging* / Q000208:ethnology / Q000503:physiopathology; D006621:Hip Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015995:Prevalence; D011379:Prognosis; D016059:Range of Motion, Articular; D056910:Republic of Korea / Q000453:epidemiology; D055815:Young Adult