Up to 33% of Young Athletes With ACL Injury, Have a 2nd One

About one-quarter to one-third of young athletes who undergo anterior cruciate ligament reconstruction will have a second ACL injury after returning to sport, according to a new study.

The researchers found that the athletes who felt confident about their knee health and function at the time of medical clearance for sports participation after the surgery had a higher likelihood of meeting all return to sport criteria but also had a higher risk of sustaining a second injury within two years of returning to sport.

The study, “Confidence, ability to meet return to sport criteria, and second ACL injury risk association after ACL-reconstruction,” was published on April 30, 2021 in the Journal of Orthopaedic Research.

“These data suggest that as health care providers, we may need to re-evaluate the tools we currently use to determine readiness to return to sport after ACL reconstruction in young athletes. In addition, we need to better evaluate the role of confidence in patients as they transition back to sports,” lead author Mark Paterno, PT, PhD, SCS, ATC of Cincinnati Children’s Hospital says.

The research team enrolled 159 athletes with an average age of 17 years in the study. They all completed return to sport criteria when cleared by their doctor after surgery. The researchers defined success as an International Knee Documentation Committee score of 90 or more and all limb symmetry index scores of 90% or higher.

Confidence rating was based on response to the Knee Injury and Osteoarthritis Outcome Score Quality of Life subscale.

The researchers then tracked the incidence of a second ACL injury for 24 months after the return to sport.

At return to sport, 37.7% of the athletes had high knee-related confidence, 26.4% met all Return to Sport criteria and 22.0% experienced a second ACL injury after returning to sport.

Overall, confident participants were twice as likely to suffer a second ACL injury (odds ratio [OR] = 2.40; 95% confidence interval [CI]: 1.21-5.20) (p = 0.02). Those athletes who were classified as confident and met all return to sport criteria were 10 times more likely to suffer that second injury (OR = 9.6; 95% CI, 1.1-84.2) (p = 0.02) compared with the athletes who lacked confidence but met all criteria.

Future research should focus on making adjustments to the return to sport criteria to better identify those at higher risker for poor outcome after anterior cruciate ligament reconstruction, the researchers said.