title: Effect of the oral contraceptive pill on ligamentous laxity.
abstract: OBJECTIVE
  Women are 4 to 8 times more likely to sustain a serious knee injury than their male counterparts. Previous studies have found that female sex steroids affect ligamentous tissue properties. The hypothesis is that there exists a difference in ligamentous laxity between oral contraceptive pill (OCP) users and nonusers.
  
  
  METHODS
  Blinded, single-factor, posttest-only control group design.
  
  
  METHODS
  McGill University Sport Medicine Clinic, Montreal, Que-bec, Canada.
  
  
  METHODS
  One hundred twenty-seven female McGill University varsity athletes.
  
  
  METHODS
  Participants filled out a screening questionnaire and underwent KT-1000 measurements by 1 blinded examiner. Exclusion criteria related to underlying knee pathology, and hormonal factors were identified with the questionnaire.
  
  
  METHODS
  Independent sample, 2-tailed t tests were performed on the nondominant knee data of the OCP users and nonusers.
  
  
  RESULTS
  Mean anterior translations at 67 N were 3.00 +/- 1.04 mm for the OCP users and 3.86 +/- 1.72 mm for the nonusers (P = 0.011); at 89 N, 3.98 +/- 1.13 mm vs. 4.83 +/- 1.82 mm, respectively (P = 0.018). Mean anterior translations at 67 N were 2.95 +/- 0.93 mm for the non-menstruating OCP users and 3.86 +/- 1.72 mm for the nonusers (P = 0.008); at 89 N, 3.88 +/- 1.06 mm vs. 4.83 +/- 1.82 mm, respectively (P = 0.011).
  
  
  CONCLUSIONS
  Oral contraceptive pill use yielded statistically significant decreases in anterior translation of the tibia as compared with nonusers. The OCP may have a role to play in the prevention of ACL injuries by prophylactically targeting 1 of the variables responsible for the increased ACL injury rates in women.
authors.affiliation: Division of Orthopedic Surgery, Montreal General Hospital, McGill University, Montreal, Quebec, Canada. paul.martineau@mail.mcgill.ca
authors.forename: Paul A
authors.initials: PA
authors.lastname: Martineau
authors.forename: Fawzi
authors.initials: F
authors.lastname: Al-Jassir
authors.forename: Eric
authors.initials: E
authors.lastname: Lenczner
authors.forename: Mark L
authors.initials: ML
authors.lastname: Burman
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000502:physiology / Q000503:physiopathology; D000070598:Anterior Cruciate Ligament Injuries; D001265:Athletic Injuries / Q000503:physiopathology; D003278:Contraceptives, Oral, Hormonal / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology; D007717:Knee / Q000502:physiology* / Q000503:physiopathology; D008023:Ligaments, Articular / Q000187:drug effects* / Q000502:physiology / Q000503:physiopathology; D016037:Single-Blind Method
chemical_list: D003278:Contraceptives, Oral, Hormonal