title: Prevalence of femoro-acetabular impingement in international competitive track and field athletes.
abstract: OBJECTIVE
  The aim of our study was to analyse the prevalence of femoro-acetabular impingement (FAI) in national elite track and field athletes compared to peers using magnetic resonance imaging (MRI) and clinical examination including impingement tests.
  
  
  METHODS
  A total of 44 participants (22 national elite track and field athletes and 22 non-athletes) underwent an MRI for radiological findings associated with FAI, including alpha angle, lateral centre edge angle (CEA), findings of labral and cartilage lesions. The study group was furthermore investigated by the hip outcome score (HOS) and a clinical hip examination including range of motion (ROM) and impingement tests.
  
  
  RESULTS
  Concerning the cam impingement, there was a significant difference measured by mean alpha angle between the athlete group (52.2 ± 7.29°) and the control group (48.1 ± 5.45°, P = 0.004). Eleven athletes showed a cam impingement, while two probands of the control group had a pincer impingement and one a mixed form (P = 0.0217). There was no statistically significant difference concerning the CEA upon evaluating pincer impingement. Seven track and field athletes had a positive impingement test, whereof three had an increased alpha angle >55°. No participant of the control group showed pathological results in the impingement test (P = 0.0121).
  
  
  CONCLUSIONS
  MRI evidence and clinical examination suggest that cam impingement is more common in elite athletes in comparison to non-athletes. At a professional level, the intense practice of track and field athletics is susceptible for FAI.
authors.affiliation: Department of Orthopaedic Sports Surgery, St. Josef-Hospital, Ruhr-University Bochum, Bochum, Germany, m.lahner@klinikum-bochum.de.
authors.forename: Matthias
authors.initials: M
authors.lastname: Lahner
authors.forename: Simone
authors.initials: S
authors.lastname: Bader
authors.forename: Philipp Alexander
authors.initials: PA
authors.lastname: Walter
authors.forename: Christian
authors.initials: C
authors.lastname: Duif
authors.forename: Christoph
authors.initials: C
authors.lastname: von Schulze Pellengahr
authors.forename: Carsten
authors.initials: C
authors.lastname: Lukas
authors.forename: Andreas
authors.initials: A
authors.lastname: Ficklscherer
authors.forename: Stefan
authors.initials: S
authors.lastname: Fickert
authors.forename: Marco
authors.initials: M
authors.lastname: Hagen
mesh_terms: D000293:Adolescent; D000328:Adult; D056352:Athletes / Q000706:statistics & numerical data*; D005260:Female; D057925:Femoracetabular Impingement / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D006621:Hip Joint / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D015995:Prevalence; D016059:Range of Motion, Articular; D014142:Track and Field; D055815:Young Adult