title: The familial predisposition toward tearing the anterior cruciate ligament: a case control study.
abstract: OBJECTIVE
  A study of 171 surgical cases and 171 matched controls was conducted to investigate whether a familial predisposition toward tearing the anterior cruciate ligament of the knee exists.
  
  
  METHODS
  Case control study; Level of evidence, 3.
  
  
  METHODS
  Patients who were diagnosed with an anterior cruciate ligament tear were matched by age (within 5 years), gender, and primary sport to subjects without an anterior cruciate ligament tear. All 342 subjects completed a questionnaire detailing their family history of anterior cruciate ligament tears.
  
  
  RESULTS
  When controlling for subject age and number of relatives, participants with an anterior cruciate ligament tear were twice as likely to have a relative (first, second, or third degree) with an anterior cruciate ligament tear compared to participants without an anterior cruciate ligament tear (adjusted odds ratio = 2.00; 95% confidence interval, 1.19-3.33). When the analysis was limited to include only first-degree relatives, participants with an anterior cruciate ligament tear were slightly greater than twice as likely to have a first-degree relative with an anterior cruciate ligament tear compared to participants without an anterior cruciate ligament tear (adjusted odds ratio = 2.24; 95% confidence interval, 1.24-4.00).
  
  
  CONCLUSIONS
  Findings are consistent with a familial predisposition toward tearing the anterior cruciate ligament.
  
  
  CONCLUSIONS
  Future research should concentrate on identifying the potentially modifiable risk factors that may be passed through families and developing strategies for the prevention of anterior cruciate ligament injuries.
authors.affiliation: Fowler Kennedy Sport Medicine Clinic, University of Western Ontario, London, Ontario, Canada.
authors.forename: R Kevin
authors.initials: RK
authors.lastname: Flynn
authors.forename: Cheryl L
authors.initials: CL
authors.lastname: Pedersen
authors.forename: Trevor B
authors.initials: TB
authors.lastname: Birmingham
authors.forename: Alexandra
authors.initials: A
authors.lastname: Kirkley
authors.forename: Dianne
authors.initials: D
authors.lastname: Jackowski
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Fowler
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000070598:Anterior Cruciate Ligament Injuries; D016022:Case-Control Studies; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007718:Knee Injuries / Q000209:etiology* / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio