Risk Factors for Second ACL Injury with Return to Sport
We have written previously about the high rates of subsequent knee injuries after an athlete returns to sport and activity after ACL surgery. Interestingly, the most common site of injury is on the opposite knee indicating athlete's are using a compensatory balance and coordination strategy during play. Current research is working on developing physical therapy rehabilitation programs to reduce the risk of injury upon return to sport. Some research has shown delaying a return to sport longer than 9 months can reduce re injury rates by as much as 84%. A current study has identified other risk factors which may place an athlete at risk for future knee injury after returning to sport following ACL reconstruction surgery.
An article in the Orthopedic Journal of Sports Medicine followed 163 patients who underwent ACL reconstruction to determine risk factors for a second ACL injury (Paterno et al. 2017). The authors reported 1 in 5 of the returning athletes sustained a second ACL injury. These athletes were then examined to determine which factors correlated with their injury. The authors placed these athletes in either a high or low risk pool based on established factors for ACL injury. High risk athletes for a second tear included one of two groups
1. < 19 years old, limited and asymmetrical triple hop distance
2. <19 years old, female sex, high knee confidence, limited and asymmetrical triple hop distance
Athletes in either high risk group were 5 times more likely to injure their ACL again compared to a lower risk athlete.
Athletes are encouraged to complete all of their prescribed physical therapy visits up to 9 months as well as successfully pass return to sport testing before considering a return to sport.