Purpose: While it is well-documented that females have a higher risk of anterior cruciate ligament (ACL) injuries than males, the role of age in mediating this injury risk has not been explored. The purpose of this study was to characterize the relationship between age and sex in predicting ACL injury in the pediatric population. The primary hypothesis was that prepubescent males are more likely to sustain an ACL injury than prepubescent females.
Methods: Data were collected from The Statewide Planning and Research Cooperative System (SPARCS) database for the state of New York from 1996-2016. The database was queried for patients </= 19 years who had been diagnosed with an ACL tear using the ICD-9 code 844.2 or the ICD-10 codes S83.512A/ S83.511A/ S83.519A. Patient age and sex at time of diagnosis with ACL injury were recorded. Chi square analysis was used to compare the frequency of ACL injury for the categorical variables age and sex, with statistical significance set at p<0.05.
Results: During the study period, 20,128 patients aged </= 19 years old were diagnosed with an ACL tear (10,830 males, 9,298 females, male:female = 1.2:1). 129 patients <12 years sustained an ACL tear (85 males, 44 females, male:female = 1.9:1), while 19,999 patients aged 12-19 years sustained an ACL tear (10,745 males, 9,254 females, male:female = 1.2:1). Chi-square analysis demonstrated a significant relationship between sex and age group (p<0.006). Additional analysis revealed that females were most at risk for ACL injury from ages 12-16 years, with 2135 males and 2994 females sustaining ACL injuries in this group, (male:female = 1:1.4, p<0.005).
Conclusion: The results of this study confirm the hypothesis that prepubescent males (those <12 years) are more likely to sustain an ACL injury than same-aged female peers. While a patient’s sex plays an important role in determining risk for ACL injury – in addition to other factors such as sport played and previous injury history – the relative risk changes throughout the pediatric and adolescent years, with males being more likely to sustain an ACL injury in the prepubertal period while females are more likely to sustain ACL injury in the pubertal period. Understanding this allows us to better individualize screening and prevention programs for ACL injury in pediatric athletes.