ACL injury occurrence in the Australian High Performance Sports System: a 5-year retrospective analysis

Introduction: The Australian High Performance Sport System (AHPSS) comprises the National Institute Network, National Sporting Organisations and other organisations focused on Olympic, Paralympic and Commonwealth Games success, and encompasses several sports such as netball and basketball which have a high incidence of anterior cruciate ligament (ACL) injuries. ACL injuries represent a substantial time, performance and financial burden to athletes and sporting organisations, yet a comprehensive epidemiological profile of the ACL injuries across AHPSS athletes has not been previously reported. Methods: AHPSS athletes who had an ACL injury recorded within the Athlete Management System between 1/1/2015 and 31/5/2020 (inclusive) were included. Demographic data were reported using descriptive statistics. Return to sport (RTS) time frames for all ACL injuries and the proportion of subsequent ACL injuries was calculated. The RTS time between sex, age groups and ACL injury category was compared using the Mann-Whitney U test and the Kruskal-Wallis test. Results: 6.4% of 2,071 knee injuries reported were ACL injuries. 68.9% of the ACL injuries were in females. The average rate was 2.03 ACL injuries per month. 48.5% of ACL injuries occurred during training and 40.9% during competition. The median RTS time was 369 days, with RTS times reducing with increasing age (X2(3) =11.781, p=0.008). The presence of concurrent injuries within the knee did not significantly affect the RTS timeframes. 25.8% of reported injuries were subsequent ACL injuries. Discussion: Two out of three ACL injuries occurred in female athletes and half in athletes aged 21 or younger. There is strong evidence to support the effectiveness of ACL injury prevention programs, and better supporting young and female athletes and their coaches to implement these programs may further improve injury prevention outcomes. On average athletes RTS at 12 months post-injury, with reduction in RTS times observed with increasing age. The reasons for this effect are unclear but may reflect differences in risk tolerance, technical ability and competition pressures between developing and experienced athletes. One in six athletes sustained at least one subsequent ACL injury, and one quarter of reported ACL injuries were subsequent injuries. Our data emphasizes the need for ongoing development of rehabilitation and RTS testing protocols that identify and address risk factors for subsequent ACL injury. There was no significant difference in RTS timeframes or proportion of athletes sustaining subsequent injuries in athletes who had an ACL injury with a concurrent knee injury (e.g., meniscal tear) compared to athletes with an isolated ACL injury. This represents important information for future athletes and coaches confronted by serious, multi-structure knee injuries. Impact and application to the field•Implementation strategies are needed to increase utilisation and ensure correct performance of ACL injury prevention programs among young athletes and female athletes.•Continued refinement is needed of evidence-based rehabilitation and testing strategies to identify and address risk factors for subsequent injuries.•The RTS prognosis of ACL-injured athletes was not affected by concurrent pathology in the knee, despite injuries with concurrent pathology often requiring modifications to the rehabilitation process. Conflict of Interest Statement: my co-authors and I acknowledge that we have no conflicts of interest of relevance to the submission of this abstract