Pediatric and Adolescent ACL Injuries

Knee injuries often occur in children and adolescents, so it is little surprise anterior cruciate ligament (ACL) injuries are becoming more common too. This is probably due to the increased number of children who now play organized sports at a younger age.

The anterior cruciate is the primary ligament in the knee that prevents the knee from giving way. It is commonly torn in sports such as soccer, alpine skiing and basketball. In adults, the ACL is usually reconstructed if the adult intends to return to activities that require twisting, turning and jumping.

Why is there controversy in treatment of ACL injuries in young people?

he reason for some controversy in treating ACL injuries in adolescents, and especially in children, is that their bones have not yet reached skeletal maturity. Bones that are still growing longer have open growth plates. Growth plates are the areas of the bone that produce the new bone that allows the bones to increase in length and diameter. When skeletal maturity is reached the growth plates closes.

The controversy involves the potential damage to the growth plates when the ACL gets reconstructed. During reconstruction, tunnels are drilled through the tibia and femur. There is concern that if the growth plates are still open they may be damaged when the drilling occurs. If there is damage to the growth plates the leg could grow crooked or even stop growing in length.

What happens to a child with an ACL injury that is treated without reconstruction?

If a child or teenager has a torn ACL, there are two schools of thought on treatment:

Try conservative treatment such as physical therapy, bracing or activity modification, until the child reaches skeletal maturity. Then, reconstruct the ligament. This line of treatment, in children and adolescents with ACL injuries, has been well studied in the recent orthopedic surgery literature. The medical studies reveal that conservative treatment results in poor function and a high rate of future knee damage. A study published in the American Journal of Sports Medicine reported that 71 percent of their skeletally immature patients with ACL injuries treated conservatively went on to tear their meniscus. The meniscus is the shock absorber in the knee that helps to cushion the knee joint and prevent early onset arthritis.

Try surgical treatment of the ACL. There have been several studies that examine children and adolescents that underwent ACL reconstruction after injury. These patients were able to return to pre-injury sporting activities, and the incidence of recurrent knee injuries was very low. The conclusion of this series of articles was that the children are at high risk of future knee damage if their ACL is not reconstructed. The reason why conservative treatment doesn't work well in children is because they do not adequately modify their activities. Adults follow doctors’ orders about exercise modifications more consistently than children do.

What do the medical studies reveal about children who have undergone ACL reconstruction?

Medical studies about the risk of leg mal alignment and growth plate closure in children who undergo ACL reconstructions have found no clinically significant limb length differences or abnormal growth related to drilling across the open growth plates. Special care must be taken when performing the ACL reconstruction. When a child with open plates undergoes an ACL reconstruction, extra equipment is used to make sure drill holes are in the center of the growth plate, in addition to using a smaller-sized graft. Only an experienced, trained, orthopedic surgeon with a sports medicine fellowship should perform this procedure.

Rehabilitation

After this procedure, rehab for children and adolescents generally follows the same program as for any adult patient. Most athletes will be able to return to twisting, turning sports within six months of surgery. The rehab, guided by a physical therapist, will focus on obtaining full extension of the knee and strengthening the hamstrings and quadriceps muscles. Intensive rehab lasts around six weeks. After this time, and based on the patient’s progress, rehab is changed to a home program. The goal is to have the leg as strong as the unaffected side by six months.