Effects of oral contraceptive use on anterior cruciate ligament injury epidemiology

Introduction/Purpose Anterior cruciate ligament injuries often incur major consequences for athletes. Elevated estrogen levels are likely increase the risk for injury. This risk may be partially or fully mitigated by the use of oral contraceptives. The purpose of this study was to determine if women undergoing anterior cruciate ligament surgical reconstruction were less likely to use oral contraceptives than matched noninjured population. Methods This is a case-control study utilizing national insurance claims data from 2002 TO 2012. Participants included women age 15-39 yr. Cases were defined as those receiving surgical reconstruction of the anterior cruciate ligament between 2002 and 2012. Controls were matched 3/1 to cases. Exposure to oral contraceptives was defined as the presence of any prescription fill for oral contraceptives during the previous 12 months to index date. Conditional multivariate logistic regression was used to estimate adjusted odds ratios for the use of oral contraceptives. Results Women age 15-19 yr undergoing surgical repair of the anterior cruciate ligament were 18% less likely to use oral contraceptives than matched controls (adjusted odds ratio, 0.82; 95% CI, 0.75-0.91; P < 0.0001). Cases among two older age groups, 25-29 and 30-34 yr, were more likely to use oral contraceptives than controls with adjusted odds ratios of 1.15 (95% CI, 1.02-1.30; P < 0.05) and 1.16 (95% CI, 1.04-1.31; P < 0.05), respectively. Conclusions The use of oral contraceptives potentially modifies anterior cruciate ligament injury risk in young women. Despite reports that athletes, who are more prone to anterior cruciate ligament injury, use oral contraceptives at about twice the rate of nonathletes, these data suggest that women ages 15-19 yr undergoing anterior cruciate ligament reconstruction used oral contraceptives at a lower rate than the general population.