title: The prognostic value of MRI in determining reinjury risk following acute hamstring injury: a systematic review.
abstract: BACKGROUND
  A challenge for sports physicians is to estimate the risk of a hamstring re-injury, but the current evidence for MRI variables as a risk factor is unknown.
  
  
  OBJECTIVE
  To systematically review the literature on the prognostic value of MRI findings at index injury and/or return to play for acute hamstring re-injuries.
  
  
  METHODS
  Databases of PubMed, Embase, MEDLINE, Scopus, CINAHL, Google Scholar, Web of Science, LILACS, SciELO, ScienceDirect, ProQuest, SPORTDiscus and Cochrane Library were searched until 20 June 2016.
  
  
  METHODS
  Studies evaluating MRI as a prognostic tool for determining the risk of re-injury for athletes with acute hamstring injuries were eligible for inclusion.
  
  
  METHODS
  Two authors independently screened the search results and assessed risk of bias using standardised criteria from a consensus statement. A best-evidence synthesis was used to identify the level of evidence. Post hoc analysis included correction for insufficient sample size.
  
  
  RESULTS
  Of the 11 studies included, 7 had a low and 4 had a high risk of bias. No strong evidence for any MRI finding as a risk factor for hamstring re-injury was found. There was moderate evidence that intratendinous injuries were associated with increased re-injury risk. Post hoc analysis showed moderate evidence that injury to the biceps femoris was a moderate to strong risk factor for re-injury.
  
  
  CONCLUSIONS
  There is currently no strong evidence for any MRI finding in predicting hamstring re-injury risk. Intratendinous injuries and biceps femoris injuries showed moderate evidence for association with a higher re-injury risk.
  
  
  BACKGROUND
  Registration in the PROSPERO International prospective register of systematic reviews was performed prior to study initiation (registration number CRD42015024620).
authors.affiliation: Department of Sports Medicine, VieCuri Medisch Centrum, Venlo, Limburg, The Netherlands.
authors.forename: Moniek
authors.initials: M
authors.lastname: van Heumen
authors.affiliation: Amsterdam Center of Evidence Based Sports Medicine, Academic Medical Center, Amsterdam, The Netherlands.|Department of Sports Medicine, The Sports Physician Group, OLVG, Amsterdam, The Netherlands.|Department of Sports Medicine, Aspetar Orthopaedics and Sports Medicine Hospital, Doha, Qatar.
authors.forename: Johannes L
authors.initials: JL
authors.lastname: Tol
authors.affiliation: Department of Orthopaedics and Sports Medicine, Erasmus MC University Medical Centre, Rotterdam, The Netherlands.
authors.forename: Robert-Jan
authors.initials: RJ
authors.lastname: de Vos
authors.affiliation: Department of Sports Medicine, Bergman Clinics, Naarden, The Netherlands.|The Sports Physician Group, Onze Lieve Vrouwe Gasthuis West, Amsterdam, The Netherlands.
authors.forename: Maarten H
authors.initials: MH
authors.lastname: Moen
authors.affiliation: Amsterdam Center of Evidence Based Sports Medicine, Academic Medical Center, Amsterdam, The Netherlands.|Sports Groin Pain Centre, Aspetar Orthopaedics and Sports Medicine Hospital, Doha, Qatar.
authors.forename: Adam
authors.initials: A
authors.lastname: Weir
authors.affiliation: School of Public Health, University of Sydney, Sydney, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Orchard
authors.affiliation: The Sports Physician Group, Amsterdam, The Netherlands.
authors.forename: Gustaaf
authors.initials: G
authors.lastname: Reurink
mesh_terms: D056352:Athletes; D001265:Athletic Injuries / Q000000981:diagnostic imaging*; D015982:Bias; D000070633:Hamstring Muscles / Q000293:injuries*; D006801:Humans; D008279:Magnetic Resonance Imaging; D011379:Prognosis; D012307:Risk Factors; D017695:Soft Tissue Injuries / Q000000981:diagnostic imaging*
keywords: Hamstring; MRI; Recurrent; Risk factor; Thigh