ACL tears are devastating knee injuries that most commonly occur in adults and skeletally mature adolescents. High school and college athletes are particularly at risk. The incidence of ACL tears among kids who have not gone through their growth spurts does appear to be rising, though. Since the decision on the best way to treat a torn ACL in a child is such a big one for parents and the young athletes, I want to review some of the questions that often arise.
What is an ACL tear?
The anterior cruciate ligament (ACL) is a ligament in the center of the knee that provides front-to-back and rotational stability to the knee. Athletes and athletic individuals tear the ACL through traumatic events in sports and other activities.
How does an athlete tear his or her ACL?
Noncontact mechanisms often cause ACL tears. A young athlete might land awkwardly from a jump or plant his or her foot to change directions and feel a loud, painful pop in the knee.
Can the torn ACL heal on its own?
In all patients, whether they are adults or kids who haven’t finished growing, a complete tear of the ligament does not heal on its own. One exception could be a tibial spine avulsion. This is a variant of an ACL ligament injury. The bony attachment of the ACL is pulled off the top of the tibia instead of the ligament itself tearing. Nondisplaced tibial spine avulsions can heal without surgery.
Does a child need to have surgery for a torn ACL?
A knee without a functioning ACL is often unstable. The child’s knee often gives way or buckles with physical activities like playing sports. The surgeon performs an ACL reconstruction, replacing or creating a new ligament in order to stabilize the knee. Theoretically a young patient could try to modify activities and/or wear a knee brace to avoid surgery until he or she is older and finished growing. Decreased ability to play often makes this option less appealing for kids and their parents. Plus, recent research has shown increased rates of secondary damage to the meniscus and articular cartilage in kids who delayed ACL reconstruction.
Does surgery injure the growth plates around the knee?
ACL reconstruction involves creating a new ligament by drilling tunnels in the tibia and femur and placing the graft into the knee within those tunnels. Drilling those tunnels in the same manner could theoretically damage portions of the growth plates if the child has not finished growing. Such damage to the growth plates could theoretically cause one leg to become slightly shorter or more angulated than the other. For that reason, many families elect to delay surgery and have the procedure when the child finishes growing.
Are there surgical techniques to decrease the risk of growth problems?
Orthopedic surgeons have modified the surgical procedures over the years to stabilize the knee without damaging the growth plates. These modified procedures use tunnels that do not cross the growth plates.
What are the best choices for a graft during ACL reconstruction?
Orthopedic surgeons typically do not use patellar tendon grafts with bone plugs in children, despite those being popular grafts in mature adolescents and adults. There appears to be a higher risk of growth arrest if the bone plug on the patellar tendon graft remains in the tunnel as it crosses the growth plate. Hamstring tendon grafts are often the most popular options for skeletally immature patients.
Since there are many treatment options for ACL tears in young athletes, parents can often be confused as to the best decision for their children. It can be a good idea to see a sports medicine orthopedic surgeon who is familiar with these surgeries in the pediatric population.