Sex Differences in the Incidence of Anterior Cruciate Ligament, Medial Collateral Ligament, and Meniscal Injuries in Collegiate and High School Sports

BACKGROUND: Previous research has noted sex-based differences in anterior cruciate ligament (ACL) injury rates in young athletes, while little is known about medial collateral ligament (MCL) and meniscal injury rates in this population. The objective of this study was to compare injury rates for traumatic knee injuries (ie, ACL, MCL, and meniscal injuries) in collegiate and high school (HS) varsity student-athletes across multiple sports. HYPOTHESIS: Knee injury rates vary by sex and across different sports and levels of competition. STUDY DESIGN: Descriptive epidemiology study. METHODS: Injury and athlete-exposure data were utilized from the National Athletic Treatment, Injury and Outcomes Network (NATION) and National Collegiate Athletic Association (NCAA) Injury Surveillance Program (ISP) during the 2009-2010 to 2013-2014 academic years. Analyses focused on ACL, MCL, and meniscal injuries. Injury rates and injury rate ratios (IRRs) with 95% CIs were calculated for basketball, ice hockey, lacrosse, soccer, and baseball/softball. RESULTS: The ACL injury rate was higher for female than male athletes at the collegiate (IRR, 2.49; 95% CI, 1.81-3.41) and HS (IRR, 2.30; 95% CI, 1.67-3.18) levels. At the collegiate level, the highest ACL IRR comparing female to male athletes was reported in softball/baseball (IRR, 6.61; 95% CI, 1.48-29.55). At the HS level, the highest ACL IRR was reported in basketball (IRR, 3.68; 95% CI, 1.91-7.10). The MCL injury rate was higher for female than male athletes at the HS level (IRR, 2.11; 95% CI, 1.25-3.56) but lower for female than male athletes at the collegiate level (IRR, 0.73; 95% CI, 0.59-0.92). The meniscal injury rate was lower for female than male athletes at the HS level (IRR, 0.47; 95% CI, 0.31-0.71), while no differences by sex were seen at the collegiate level (IRR, 1.35; 95% CI, 0.90-2.02). CONCLUSION: Knee injury rates varied by sex across 5 different sports in the HS and collegiate settings. Female athletes sustained ACL injuries at a higher rate than male athletes at both the HS and collegiate levels in these 5 sports; however, there was not a distinct sex disparity in MCL and meniscal injuries. Future studies should examine the rates of concomitant and recurrent injuries to inform injury prevention and rehabilitation programs.