title: Combined anterior and rotational laxity measurements allow characterizing personal knee laxity profiles in healthy individuals.
abstract: OBJECTIVE
  The aim of this study was to quantify sagittal and rotational knee laxity profiles taking into account individual influencing factors.
  
  
  METHODS
  Linear regression models were used to determine which individual characteristics (age, height, body mass and sex) influenced the outcome in a group of 104 healthy subjects. The standardized residuals were used as individualized (corrected) laxity scores and were combined to determine knee laxity profiles.
  
  
  RESULTS
  Anterior knee laxity was not influenced by individual characteristics. Rotational knee laxity was higher in females and inversely related to body mass. The correlation between anterior laxity and internal rotation scores was weak (r = 0.24, p = 0.02). The proportion of knees concerned by increased laxity scores (scores >1) was similar for anterior displacement, internal and external rotation (15 %). Only 32 % of the tested subjects showed a normal profile (score >-1 and <1) for all three directions, 33 % were concerned by hyperlaxity, 40 % by hypolaxity and 5 % by both.
  
  
  CONCLUSIONS
  The diversity of laxity profiles found here highlights that the interpretation of multidirectional knee laxity is complex and suggests the necessity for individualized care of knee diseases and injuries. These results contribute to the understanding of knee laxity and throw the basis for prevention strategies and improvement of treatment outcomes in injuries and diseases.
  
  
  METHODS
  Case series with no comparison groups, Level IV.
authors.affiliation: Sport Medicine Research Laboratory, Public Research Center for Health, Luxembourg, Luxembourg.
authors.forename: Caroline
authors.initials: C
authors.lastname: Mouton
authors.affiliation: Sport Medicine Research Laboratory, Public Research Center for Health, Luxembourg, Luxembourg.|Department of Orthopaedic Research, Centre Hospitalier of Luxembourg, Luxembourg, Luxembourg.
authors.forename: Romain
authors.initials: R
authors.lastname: Seil
authors.affiliation: Institute of Sports and Preventive Medicine, Saarland University, Saarbrūcken, Germany.
authors.forename: Tim
authors.initials: T
authors.lastname: Meyer
authors.affiliation: Sport Medicine Research Laboratory, Public Research Center for Health, Luxembourg, Luxembourg.
authors.forename: Hélène
authors.initials: H
authors.lastname: Agostinis
authors.affiliation: Sport Medicine Research Laboratory, Public Research Center for Health, Luxembourg, Luxembourg. daniel.theisen@crp-sante.lu.
authors.forename: Daniel
authors.initials: D
authors.lastname: Theisen
mesh_terms: D000328:Adult; D053587:Arthrometry, Articular; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis*; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular; D012016:Reference Values; D012399:Rotation; D055815:Young Adult
keywords: Anterior knee laxity; Knee laxity profiles; Rotational knee laxity