"ACL tears in the growing athlete"-Issue 8

The anterior cruciate ligament, or ACL, is one of four ligaments that keep the knee from wobbling or giving way when we move. To fully understand the impact of an ACL tear, it helps to know a little about how the knee works. As you can see in the diagram to the left, the knee is a large joint where the tibia meets the femur. The ACL connects the front of the tibia to the back of the femur. Its job is to make sure that the tibia does not slide in front of the femur, helping to maintain the stability of the joint.

In active children, ACL tears are among the most severe and most frequent sport and play related injuries. This year, in the United States alone, an estimated 250,000 people will tear their ACL. The vast majority will be among women ages 15 to 25, as females are five to eight times more likely to injure their ACL than boys of the same age.

           When the knee is forced into an unusual position, the ACL can tear. Typically, when the ACL is torn, the child will feel his/her knee “give way”, often associated with an audible popping sound. Over the next several hours the child will begin to experience pain, swelling and instability in the knee. To help protect your child from further injury, it is important to get a thorough evaluation from your physician for accurate diagnosis and proper treatment. ACL tears are typically managed with a combination of surgical repair and physical therapy. Your child’s age will be a determining factor for when surgery is most appropriate.

The bones and joints of children are very different from adults, because the child’s bones are still “growing”. This can make caring for children with an ACL tear a bit more complicated. If you can recall from our previous blogs, bones grow from the “growth plate”, which in the knee are located in the ends of the femur and the tibia bones.

 Most modern surgical techniques for ACL repair involve drilling tunnels in the bone through the area of the growth plate. This does not create problems in adults, because the growth plate closes at the time of skeletal maturity. Drilling through these regions while the growth plate remains open, places the child at risk for growth disturbances.

Often, surgeons will recommend delaying surgical repair until skeletal maturity is reached.  During that time, physical therapy is typically initiated for injury management.

In some cases, ACL injuries in children can create enough instability in the knee that return to sport/activity without immediate surgical repair places the athlete at high risk of further injury.

Being faced with the decision of whether or not to have surgery performed on your child is a very difficult situation to be in. Many parents are faced with questions and anxiety about what will happen if they do not have surgery right away. Each decision about ACL surgery in children is unique. You will need to have a discussion with your physician about all potential options and how to make a decision that you and your child will be most comfortable with.

Recovery from an ACL surgery is a lengthy process that can take up to 6 to 12 months, but 90% of kids return to activity/sport without knee instability. As always, prevention is KEY! Seek out ACL prevention programs to help protect your child from future injury. For more information about this topic and others, contact your local physician or physical therapist. 

References:
1. Moksnes H. et al. Management of Anterior Cruciate Ligament Injuries in Skeletally Immature Individuals. Journal of Orthopedic and Sports Physical Therapy. 2012;3:172-195
2. Wilk K. et al. The Challenge of Return to Sports for Patients Post-ACL Reconstruction. Journal of Orthopedic and Sports Physical Therapy. 2012; 4:300-301.
3.www.childrenshospital.org
4.www.seattlechildrens.org