title: Femoroacetabular impingement in former high-level youth soccer players.
abstract: BACKGROUND
  Femoroacetabular impingement (FAI) can be a source of hip pain in young adults. Repetitive kicking associated with youth soccer may lead to morphologic changes of the proximal femur that predispose a person to the development of FAI.
  
  
  OBJECTIVE
  Young adults who participated in high-level soccer competition as youths are more likely to demonstrate radiographic changes consistent with FAI and to have increased alpha angles as compared with controls.
  
  
  METHODS
  Cross-sectional study; Level of evidence, 3.
  
  
  METHODS
  Pelvic radiographs (anteroposterior and frog-lateral) were obtained on 50 individuals who participated in high-level soccer during skeletal immaturity and 50 controls who did not participate in high-level soccer. There were 25 men and 25 women in each group. All subjects were between 18 and 30 years of age, had a body mass index of less than 30, and had not sought or received treatment for hip disorders. Radiographs were analyzed independently for the presence of FAI, and alpha angles were measured. Hips with alpha angles that measured greater than or equal to 55° were deemed to have cam deformity.
  
  
  RESULTS
  Fifteen of the 25 male subjects had evidence of cam deformity, compared with 14 male controls. Nine of the 25 female subjects had evidence of cam deformity, compared with 8 female controls. Neither of these differences was statistically significant. There was a significantly higher prevalence of cam deformity in men as compared with women (29 vs 17, P = .016).
  
  
  CONCLUSIONS
  Participation in high-level soccer during skeletal immaturity is not associated with a higher risk of development of cam deformity in the young adult years. There is a high prevalence of cam deformity in the young adult population. Males demonstrate a higher prevalence of cam deformity than do females.
authors.affiliation: Michigan State University/Kalamazoo Center for Medical Studies, Department of Orthopaedic Surgery, Kalamazoo, Michigan, USA. adjohnso@salud.unm.edu
authors.forename: Adam C
authors.initials: AC
authors.lastname: Johnson
authors.forename: Mark A
authors.initials: MA
authors.lastname: Shaman
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Ryan
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging / Q000293:injuries; D000293:Adolescent; D000328:Adult; D056352:Athletes / Q000706:statistics & numerical data*; D001265:Athletic Injuries / Q000150:complications / Q000000981:diagnostic imaging / Q000453:epidemiology*; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D057925:Femoracetabular Impingement / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology; D025981:Hip Injuries / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D008297:Male; D015995:Prevalence; D011859:Radiography; D012737:Sex Factors; D012916:Soccer / Q000293:injuries*; D055815:Young Adult