title: Descriptive epidemiology of femoroacetabular impingement: a North American cohort of patients undergoing surgery.
abstract: BACKGROUND
  Symptomatic femoroacetabular impingement (FAI) is associated with hip pain, functional limitations, and secondary osteoarthritis. There is limited information from large patient cohorts defining the specific population affected by FAI. Establishing a large cohort will facilitate the identification of "at-risk" patients and will provide a population for ongoing clinical research initiatives. The authors have therefore established a multicenter, prospective, longitudinal cohort of patients undergoing surgery for symptomatic FAI.
  
  
  OBJECTIVE
  To report the clinical epidemiology, disease characteristics, and contemporary surgical treatment trends in North America for patients with symptomatic FAI.
  
  
  METHODS
  Cross-sectional study; Level of evidence, 3.
  
  
  METHODS
  Upon approval of the institutional review boards at 8 institutions, 12 surgeons enrolled consecutive patients undergoing surgical intervention for symptomatic FAI. Patient demographics, physical examination data, radiographic data, diagnoses, operative data, and standardized patient-reported outcome measures were collected. The first 1130 cases are summarized in this study.
  
  
  RESULTS
  A total of 1076 consecutive patients (1130 hips) were enrolled; 55% (n = 622) were female, and 45% (n = 508) were male, with an average age of 28.4 years and average body mass index (BMI) of 25.1. Demographics revealed that 88% of patients who were predominantly treated for FAI were white, 19% reported a family history of hip surgery, 47.6% of hips had a diagnosis of cam FAI, 44.5% had combined cam/pincer FAI, and 7.9% had pincer FAI. Preoperative clinical scores (pain, function, activity level, and overall health) indicated a major dysfunction related to the hip. Surgical interventions were arthroscopic surgery (50.4%), surgical dislocation (34.4%), reverse periacetabular osteotomy (9.4%), limited open osteochondroplasty with arthroscopic surgery (5.8%), and limited open by itself (1.5%). More than 90% of the hips were noted to have labral and articular cartilage abnormalities at surgery; femoral head-neck osteochondroplasty was performed in 91.6% of the surgical procedures, acetabular rim osteoplasty in 36.7%, labral repair in 47.8%, labral debridement in 16.3%, and acetabular chondroplasty in 40.1%.
  
  
  CONCLUSIONS
  This multicenter, prospective, longitudinal cohort is one of the largest FAI cohorts to date. In this cohort, FAI occurred predominantly in young, white patients with a normal BMI, and there were more female than male patients. The disease pattern of cam FAI was most common. Contemporary treatment was predominantly arthroscopic followed by surgical hip dislocation.
authors.affiliation: John C. Clohisy, Washington University, 11300 West Pavilion, Campus Box 8233, One Barnes-Jewish Hospital Plaza, St Louis, MO 63110. clohisyj@wudosis.wustl.edu.
authors.forename: John C
authors.initials: JC
authors.lastname: Clohisy
authors.forename: Geneva
authors.initials: G
authors.lastname: Baca
authors.forename: Paul E
authors.initials: PE
authors.lastname: Beaulé
authors.forename: Young-Jo
authors.initials: YJ
authors.lastname: Kim
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Larson
authors.forename: Michael B
authors.initials: MB
authors.lastname: Millis
authors.forename: David A
authors.initials: DA
authors.lastname: Podeszwa
authors.forename: Perry L
authors.initials: PL
authors.lastname: Schoenecker
authors.forename: Rafael J
authors.initials: RJ
authors.lastname: Sierra
authors.forename: Ernest L
authors.initials: EL
authors.lastname: Sink
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Sucato
authors.forename: Robert T
authors.initials: RT
authors.lastname: Trousdale
authors.forename: Ira
authors.initials: I
authors.lastname: Zaltz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018771:Arthralgia / Q000209:etiology; D001182:Arthroscopy; D015992:Body Mass Index; D002358:Cartilage, Articular / Q000002:abnormalities; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D057925:Femoracetabular Impingement / Q000145:classification / Q000453:epidemiology* / Q000601:surgery*; D006621:Hip Joint / Q000601:surgery*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009656:North America / Q000453:epidemiology; D010027:Osteotomy; D044469:Racial Groups / Q000706:statistics & numerical data; D055815:Young Adult
keywords: FAI; epidemiology; hip arthroscopic surgery; surgical hip dislocation