title: Radiographic predictors of femoroacetabular impingement treatment outcomes.
abstract: OBJECTIVE
  To review the literature on femoroacetabular impingement (FAI) treatment outcomes, specifically focusing on potential pre-operative radiographic parameters that may provide prognostic information regarding outcomes following surgical management.
  
  
  METHODS
  A comprehensive review of computerized literature databases (Medline Ovid and PubMed) was performed, searching for articles reporting on FAI treatment outcomes. A single reviewer screened titles, abstracts and performed full-text reviews of eligible studies. The references of these studies were further screened for additional potentially relevant studies. A total of 243 studies were reviewed, with 18 meeting inclusion criteria.
  
  
  RESULTS
  Thirteen arthroscopic studies reported on 1556 patients, with clinical improvement in 35-92 % of patients and associated failure rates of 12-71 %. Five open surgical studies reported on 238 patients with clinical improvement in 65-95 % of patients and associated failure rates of 0-35 %. Both arthroscopic and open studies identified inferior outcomes with pre-operative radiographic findings of an elevated Tönnis grade (grade 2 or higher), joint space <2 mm, lateral centre-edge angle (LCEA) <20° and incomplete femoral osteoplasty.
  
  
  CONCLUSIONS
  Pre-operative radiographic findings of osteoarthritis (Tönnis grade 2/3, <2 mm joint space) or dysplasia (LCEA < 20°) should be considered relative contraindications to joint preservation surgery as outcomes are worse among these patients and associated with a higher risk of conversion to total hip arthroplasty. Care should also be taken to perform a thorough femoral osteoplasty to reduce the risk of failure and need for revision surgery.
  
  
  METHODS
  III.
authors.affiliation: Center for Hip Pain and Preservation, Hospital for Special Surgery, 541 East 71st Street, New York, NY, 10021, USA. ryan.degen@gmail.com.
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Degen
authors.affiliation: Center for Hip Pain and Preservation, Hospital for Special Surgery, 541 East 71st Street, New York, NY, 10021, USA.
authors.forename: Danyal H
authors.initials: DH
authors.lastname: Nawabi
authors.affiliation: Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, USA.
authors.forename: Asheesh
authors.initials: A
authors.lastname: Bedi
authors.affiliation: Center for Hip Pain and Preservation, Hospital for Special Surgery, 541 East 71st Street, New York, NY, 10021, USA.
authors.forename: Bryan T
authors.initials: BT
authors.lastname: Kelly
mesh_terms: D019644:Arthroplasty, Replacement, Hip; D001182:Arthroscopy; D057925:Femoracetabular Impingement / Q000000981:diagnostic imaging* / Q000601:surgery; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D011237:Predictive Value of Tests; D016059:Range of Motion, Articular; D012086:Reoperation; D016896:Treatment Outcome
keywords: Femoroacetabular impingement; Hip; Radiographic predictors; Systematic review