title: The diagnostic and prognostic value of ultrasonography in soccer players with acute hamstring injuries.
abstract: BACKGROUND
  An injury to the hamstring muscle complex is the most common injury in soccer. Ultrasound of acute hamstring injuries is often used as a clinical tool for diagnosing hamstring injuries and guiding players in when they can return to play.
  
  
  OBJECTIVE
  To (1) investigate the characteristic sonographic findings of acute hamstring injuries in soccer players, (2) compare the mean injury severity (time to return to play) in injured players with and without sonographically verified abnormalities, and (3) correlate the length of the injured area and absence from soccer play (time to return to play) to investigate if ultrasonography can be used as a prognostic indicator of time to return to play.
  
  
  METHODS
  Case series; Level of evidence, 4.
  
  
  METHODS
  Players from 50 teams participating in 1 of the top 5 Danish soccer divisions were followed in the period from January to December 2008. Of 67 players with acute hamstring injuries, 51 underwent ultrasonographic examination of the injured thigh and were included in this study.
  
  
  RESULTS
  Ultrasonographic examinations were performed 1 to 10 days after injury (mean, 5.2 ± 3.0 days), and sonographic findings were present in 31 of 51 cases (61%). Two thirds of the injuries were to the biceps femoris muscle and one third to the semitendinosus muscle. No total ruptures were documented. The 51 acute hamstring injuries resulted in absence from soccer of a mean 25.4 ± 15.7 days per injury, with no significant difference between players with and without sonographically verified abnormalities (P = .41). No correlation existed between the length of the injured area and injury severity (r = 0.19, P = .29).
  
  
  CONCLUSIONS
  The biceps femoris is the most commonly injured hamstring muscle detected by ultrasound, and more than half of the injuries are intramuscular. Because neither the presence of sonographic findings nor the size of the findings was correlated with time to return to play in injured soccer players, the prognosis of hamstring injuries should not be guided by these findings alone.
authors: Jesper Petersen, Amager Hospital, Arthroscopic Centre Amager, Italiensvej 1, Copenhagen S, Denmark, DK-2300. jesper.petersen@dadlnet.dk.
authors: Jesper
authors: J
authors: Petersen
authors: Kristian
authors: K
authors: Thorborg
authors: Michael Bachmann
authors: MB
authors: Nielsen
authors: Thomas
authors: T
authors: Skjødt
authors: Lars
authors: L
authors: Bolvig
authors: Niels
authors: N
authors: Bang
authors: Per
authors: P
authors: Hölmich
mesh_terms: D000208:Acute Disease; D003718:Denmark; D006801:Humans; D015601:Injury Severity Score; D007869:Leg Injuries / Q000000981:diagnostic imaging* / Q000209:etiology; D008297:Male; D018482:Muscle, Skeletal / Q000293:injuries*; D010808:Physical Examination; D011379:Prognosis; D011446:Prospective Studies; D020127:Recovery of Function; D012008:Recurrence; D012916:Soccer / Q000293:injuries*; D013848:Thigh; D014463:Ultrasonography; D055815:Young Adult
keywords: football; hamstring; injury; soccer; sonography; ultrasonography