title: MRI assessment of calf injuries in Australian Football League players: findings that influence return to play.
abstract: OBJECTIVE
  Calf muscle strains have become increasingly prevalent in recent seasons of the Australian Football League (AFL) and represent a significant cause of time lost from competition. The purpose of this study was to examine the association between MRI features of calf muscle strains and games missed and to thereby identify parameters that are of prognostic value.
  
  
  METHODS
  A retrospective analysis of MRI scans of AFL players with calf strains referred to a musculoskeletal radiology clinic over a 5-year period (2008-2012) was performed. The muscle(s) and muscle component affected, the site and size of strain, and the presence of an intramuscular tendon tear or intermuscular fluid were recorded. These data were cross-referenced with whether a player missed at least one game. Imaging features of prognostic value were thus identified.
  
  
  RESULTS
  Sixty-three athletes had MRI scans for calf muscle strains. Soleus strains were more common than strains of other muscles. Players with soleus strains were more likely to miss at least one game if they had multiple muscle involvement (p = 0.017), musculotendinous junction strains (p = 0.046), and deep strains (p = 0.036). In a combined analysis of gastrocnemius and soleus strains, intramuscular tendon tears were observed in a significantly greater proportion of players who missed games (p = 0.010).
  
  
  CONCLUSIONS
  Amongst AFL players with calf injuries, there is an association between missing at least one game and multiple muscle involvement, musculotendinous junction strains, deep strain location, and intramuscular tendon tears. In this setting, MRI may therefore provide prognostic information to help guide return-to-play decisions.
authors.affiliation: Victoria House Medical Imaging, 316 Malvern Road, Prahran, 3181, Victoria, Australia.
authors.forename: George
authors.initials: G
authors.lastname: Waterworth
authors.affiliation: Victoria House Medical Imaging, 316 Malvern Road, Prahran, 3181, Victoria, Australia. Sara.Wein@i-med.com.au.
authors.forename: Sara
authors.identifier: http://orcid.org/0000-0003-3670-3296
authors.initials: S
authors.lastname: Wein
authors.affiliation: Melbourne Epicentre, Royal Melbourne Hospital, University of Melbourne, Parkville, Australia.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Gorelik
authors.affiliation: Victoria House Medical Imaging, 316 Malvern Road, Prahran, 3181, Victoria, Australia.
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Rotstein
mesh_terms: D001265:Athletic Injuries / Q000000981:diagnostic imaging*; D005538:Football / Q000293:injuries*; D006801:Humans; D007869:Leg Injuries / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D012189:Retrospective Studies; D000068958:Return to Sport; D013180:Sprains and Strains / Q000000981:diagnostic imaging*; D055815:Young Adult
keywords: Athlete; Calf; MRI; Muscle injury; Soleus; Strain