title: Increase in ACL and PCL injuries after implementation of a new professional football league.
abstract: OBJECTIVE
  In the season 2008-2009, a third professional football league was established in Germany. This study analysed the influence of increased training and playing intensity on severe knee injuries in football players.
  
  
  METHODS
  In a prospective controlled one-season trial, injury incidence and injury patterns of players of the newly established professional football league were analysed, particularly with regard to ruptures of the anterior (ACL) and posterior (PCL) cruciate ligaments. Players of the highest amateur level served as a control group.
  
  
  RESULTS
  Four hundred and eight players of 24 teams were allocated to two groups. The overall training exposure was significantly (p < 0.001) higher in the new professional league (335.3 h per player) than at the amateur level (286.6 h per player). Players at both levels showed similar overall injury rates and injury patterns. However, players in the professional league had a significantly higher (p = 0.04) incidence of ACL and PCL injuries, than players at the amateur level. More than 90 % of all ACL and PCL ruptures in both groups were sustained by players, who had played at least one level lower in the previous season. In addition, injuries of players who had sustained repeat injuries over the season were more severe.
  
  
  CONCLUSIONS
  The introduction of a new professional football league increased the training and playing intensity of players as well as the number of ACL and PCL ruptures. A specific injury prevention concept, particularly for players facing rapidly increasing training and playing intensity, seems to be mandatory.
  
  
  METHODS
  Prospective controlled cohort study, Level II.
authors.affiliation: Department of Trauma Surgery, University Medical Centre Regensburg, FIFA Medical Centre of Excellence, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany. werner.krutsch@ukr.de.
authors.forename: Werner
authors.initials: W
authors.lastname: Krutsch
authors.affiliation: Centre for Clinical Studies, University Medical Centre Regensburg, Regensburg, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Zeman
authors.affiliation: Department of Trauma Surgery, University Medical Centre Regensburg, FIFA Medical Centre of Excellence, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Zellner
authors.affiliation: Department of Trauma Surgery, University Medical Centre Regensburg, FIFA Medical Centre of Excellence, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Pfeifer
authors.affiliation: Department of Trauma Surgery, University Medical Centre Regensburg, FIFA Medical Centre of Excellence, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Nerlich
authors.affiliation: Department of Trauma Surgery, University Medical Centre Regensburg, FIFA Medical Centre of Excellence, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.|sporthopaedicum Straubing/Regensburg, Regensburg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Angele
mesh_terms: D000293:Adolescent; D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries / Q000453:epidemiology / Q000209:etiology*; D003163:Competitive Behavior; D015444:Exercise; D005858:Germany / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D016119:Posterior Cruciate Ligament / Q000293:injuries*; D011446:Prospective Studies; D012307:Risk Factors; D012916:Soccer / Q000293:injuries*; D055815:Young Adult
keywords: ACL ruptures; Injury prevention; Injury severity; PCL ruptures; Professional football; Soccer