First, I would like to commend the authors for a well-designed and well-powered multivariate analysis of risk factors associated with non-contact ACL injury. Vacek and colleagues clearly demonstrated the risk of non-contact injury is not only multifactorial in nature but, perhaps more importantly, that the risk factors differ between male and female athletes. For female athletes, parental history of ACL injury, increased anteroposterior knee laxity as measured with a KT-1000 and increased body mass index (BMI) significantly increased the odds of non-contact ACL injury. For male athletes, structural features that are thought to be involved with an increased likelihood of valgus knee collapse, including KT-1000 measures, quadriceps angle and navicular drop, significantly increased the risk of non-contact ACL injury.
Clinically, the results of this study provide physicians, certified athletic trainers and other sports medicine professionals with specific factors to proactively identify athletes at increased risk of non-contact ACL injury. These measures, which include parental injury history, KT-1000 measurements, BMI, quadriceps angle and navicular drop, can be readily implemented in routine annual preseason physicals. Most of these time-efficient measures, with the exception of the KT-1000, can be done without additional costly equipment thus lowering barriers to early identification of the athletes at greatest risk of ACL injury. This then allows for targeted use of injury prevention programs and/or other interventions to be employed in an effort to lessen the likelihood of ACL injury for this at-risk population.
Darren L. Johnson, MD
Professor and Chair of Orthopaedic Surgery
Director of Sports Medicine
University of Kentucky
Disclosures: Johnson reports no relevant financial disclosures.