Knee injuries in children with tears of the anterior cruciate ligament (ACL) and meniscus have increased dramatically over the past 12 years, say orthopaedic surgeons from The Children's Hospital of Philadelphia who presented their findings today at the American Academy of Pediatrics annual meeting in Boston.

"Many people in sports medicine have assumed that these knee injuries have increased in recent years among children," said J. Todd Lawrence, M.D., Ph.D., orthopaedic surgeon at The Children's Hospital of Philadelphia and primary investigator of this study. "Our study confirmed our hypothesis that, at least at our large academic pediatric hospital, knee injuries are an ever-growing problem for children and adolescents involved in sports." Lawrence added that people have suggested that greater participation in sports, increased clinician awareness of the signs and symptoms of ACL and meniscus tears, and advances in imaging technology may account for this increase.

The study team performed a retrospective review of records for all patients under 18 with ACL and meniscus tears treated at The Children's Hospital of Philadelphia from January 1999 through January 2011, and compared them to patients that sustained tibial spine fractures during that same time period. A total of 155 tibial spine fractures, 914 ACL tears and 996 meniscus tears were identified. Tibial spine fractures increased by only 1 per year, whereas ACL tears increased by more than 11 per year and meniscus tears increased by almost 14 per year. "Since tibial spine fractures were once thought to be the pediatric equivalent of an ACL tear," said Lawrence, "this continued rise in ACL tears in children suggests that injury patterns are changing and that the true incidence of these injuries is increasing."