A new study quantifies the risks and benefits of repairing anterior cruciate ligament injuries in athletes under the age of 14.

The study, released last week during the annual meeting of the American Orthopaedic Society for Sports Medicine, found that a delay in treatment of ACL injuries of more than 12 weeks led to about a four-fold increase in irreparable medial meniscus tears, an 11-fold increase in lateral compartment chondral injuries and a three-fold increase in patellotrochlear injuries. A delay in treatment also significantly increased issues related to knee instability.

Researchers developed the findings after analyzing the records of 69 patients ages 14 and under who had undergone reconstruction of their ACLs between 1991 and 2005.

The author of the study, Theodore J. Ganley, director of the Sports Medicine and Performance Center for the Children’s Hospital of Pennsylvania and the University of Pennsylvania School of Medicine, said the results help quantify the risk associated with delaying ACL reconstruction in young athletes and emphasize the need for continued injury-prevention efforts.

“The risk of inducing a growth disturbance with early reconstruction of a torn ACL must be balanced against the risk of further knee damage by delaying treatment until closer to skeletal maturity,” Ganley said. “Our study measured the independent risk factors for and relative risk of meniscal and chondral injuries in pediatric ACL patients.”