Over the past two decades, as more children and teens have participated in organized sports at younger ages and with more intense training doctors have seen an increase in a type of injury that can have devastating consequences.
Increasing numbers of young athletes, especially girls, are tearing their anterior cruciate ligament, or ACL, which provides stability to the knee. The increase is particularly dramatic in girls, in sports including high school soccer, basketball, volleyball and gymnastics.
To equip primary care doctors to evaluate these injuries, the American Academy of Pediatrics (AAP) is publishing a clinical report to guide doctors in diagnosing and treating ACL injuries in young athletes. The report, “Anterior Cruciate Ligament Injuries: Diagnosis, Treatment, and Prevention,” will be published in the May 2014 issue of Pediatrics (published online April 28).
The report outlines the approach to treating ACL injuries, including less-invasive surgery techniques that protect the developing growth plates in young athletes.
More critically, the report recommends proven ways athletes can reduce their risk of injury in the first place. Research demonstrates that specific types of physical training can reduce the risk of ACL injury as much as 72 percent, especially in young women.
"Neuromuscular training programs strengthen lower extremity muscles, improve core stability, and teach athletes how to avoid unsafe knee positions," said Cynthia LaBella, MD, FAAP, lead author of the report and a member of the AAP Council on Sports Medicine and Fitness.
The AAP recommends plyometric and strengthening exercises to reduce athletes’ risks of being injured, and encourages coaches and school sports programs to learn about the benefits of this kind of neuromuscular training. Click here for a list of training programs.
The ACL is one of the four major ligaments that stabilize the knee joint, and it helps protect the knee when landing from a jump, pivoting, or slowing down from a run. As pre-teens enter into puberty and grow taller and heavier, their risk of ACL injury increases – beginning at age 12 for girls, and age 14 for boys. Girls are at higher risk of ACL injury because after puberty, as their body size increases, girls do usually not develop more muscle power, said Timothy Hewett, PhD, FASCM, co-author of the report.
“After puberty, girls have a ‘machine motor mismatch’,” Dr. Hewett said. “In contrast, boys get even more powerful relative to their body size after their growth spurt. The good news is that we’ve shown that with neuromuscular training, we can boost the power of girls’ neuromuscular engine, and reduce their risk of ACL injuries.”
Female athletes between 15 and 20 years old account for the largest number of ACL injuries. At the high school level, girls soccer has the most ACL injuries, followed by boys football, girls basketball, girls gymnastics, and boys and girls lacrosse. Among high school and college athletes, females have two to six times higher ACL injury rates than males in similar sports. Compared with boys, girls are more likely to have surgery and less likely to return to sports after an ACL injury.
The effects of an ACL tear can be long-lasting. Injured athletes who become distanced from their sport and its social network can experience depression, and time away from school for treatments can impact academic performance. Athletes with ACL injury are up to 10 times more likely to develop early-onset degenerative knee osteoarthritis, which limits their ability to participate in sports and often leads to chronic pain and disability. Research suggests half of patients with an ACL injury will develop degenerative knee osteoarthritis in 10 to 20 years.
“This is important, because it means athletes who suffer an ACL tear at age 13 are likely to face chronic pain in their 20s and 30s,” said Dr. LaBella.
In the past, doctors and families often deferred surgery until the child reached skeletal maturity. But more sophisticated surgical techniques that avoid impacting the growth plate mean athletes can have surgery to stabilize the knee and return to their sport. Overall, ACL surgery is about 90 percent successful in restoring knee stability and patient satisfaction.
“In many cases, surgery plus rehabilitation can safely return the athlete back to sports in about nine months,” said William Hennrikus, MD, FAAP, co-author of the report. “Parents who are considering surgery for their child should seek out a pediatric orthopedic surgeon with sports medicine training.”