An injury to the anterior cruciate ligament can be frustrating for adults, but it's often devastating for young athletes who are eager to rejoin their friends on the playing field.
It's becoming more common for active kids to tear this important ligament that controls the stability and mobility of the knee, and the recovery process can take up to a year or more.
"The highest risk category is kids who are going through growth quickly, because their bodies have elongated quickly and their bodies act as levers," said Dan Enz, PT, a physical therapist with the UW Health Sports Rehabilitation Department. "And with teens, who are often more active in competition and playing sports year-round, their bodies are sometimes growing faster than they can control. That lever puts increased force through their knee and puts them at greater risk."
Most pediatric ACL injuries occur during sports. While no sport is 100 percent safe from this type of injury, the highest risk sports tend to be soccer, football, basketball, downhill skiing and lacrosse, said Pamela Lang, a UW Health Kids pediatric sports and orthopedic surgeon.
"But it can also happen during regular kid things: Playing tag, jumping on trampolines, anytime when kids are being more active," Lang said. "It tends to happen when kids are doing things that involve cutting, pivoting and jumping."
Here's what to know about preventing and treating ACL injuries in youth:
Avoid single-sport specialization
Mixing it up by playing different sports at different times of the year lowers the demands on the body. Avoiding muscle fatigue might help prevent ACL tears.
Risk grows during adolescence
"With more and more kids playing organized sports, we start to see these injuries around age 7 and 8, but when we really see it peak is around adolescence, with kids ages 14-18," Lang said. "During adolescence, kids are growing and muscles are getting stronger. They're starting to develop changes in movement patterns and they're still learning movement in their changing bodies. We think that's a big part of why we see an increase in ACL injuries in adolescents."
Risk can also rise as teens start to play more intensely at the high school level. "We start to worry about there being a fatigue factor" Lang said.
Girls face higher risk
Girls are two to four times more likely to tear their ACL than boys.
"There are likely multiple factors that contribute to that difference. Hormonal factors and anatomy may contribute to some degree, but neuromuscular control is thought to be a strong factor," Lang said. "Girls are generally more dominant with their quads than hamstrings, which fights against the ACL. The ways girls land when jumping also tends to differ and is associated with increased strain on the ACL."
Consider a prevention program
"We try to encourage coaches and school athletic programs to incorporate small exercises to optimize biomechanics so that kids are squatting and jumping correctly," Lang said. "Because younger people are still developing their movement patterns, we think we might be able to have even more of an impact if we teach them right the first time."
Ask your child's coach about ACL injury prevention drills.
Plan on surgery if your child tears their ACL
The "wait and see" approach sometimes used with adults doesn't make as much sense for active kids. An unstable knee can further damage the cartilage, putting your child on the fast track to arthritis and other problems.
"We used to wait until young patients were fully grown and skeletally mature before doing surgery," Lang said. "The problem with that is it's really hard to keep a kid from running, jumping and playing, so the activity restrictions that came with delaying surgery weren't effective. Kids were getting injuries to other parts, like the meniscus of the knee. Now we believe a more stable knee is a healthier knee, so we try to reconstruct the ACL earlier."
The surgical technique with pediatric patients is a little different because of their open growth plates. The surgeon will be careful to avoid drilling tunnels through the growth plates and will use your child's own tissue as a graft to reconstruct the torn ACL.
Commit to physical therapy
Your child will start physical therapy even before surgery to decrease swelling and restore motion and strength. After surgery, the physical therapist will help your son or daughter improve motion, mobility and strength. The physical therapist will initially start working on easy tasks such as walking, progressing to impact and cutting and pivoting moments required by multidirectional sports as the rehab process progresses. Learn more about the rehabilitation process after ACL reconstruction.
Urge your child to stay patient during rehab
Recent research shows that an athlete's risk of re-injury decreases significantly — by 51 percent — if he or she waits nine months instead of just six months after surgery before returning to athletics, and they could need even more time.
"This is not a six-month recovery," Enz said. "We're finding it's one to two years before the body is totally incorporating that tissue."
Lang added: "These kids seem to be in a great rush to return to their sport and are at a high risk of re-injury. It's a challenge getting them to buy into the recovery and think about the health of their knee long-term and not just about their next basketball season."
The re-injury rate is high
Between 85 to 95 percent of patients return to their sport after tearing their ACL, but patients under 18 face a 15 to 35 percent chance of reinjuring their ACL on the same side or the other side, Lang said. "We seem to be pretty good at getting kids back out there, but maybe not as good about getting them out as safe as they could be, considering the re-injury rate," she said.
There's a psychological recovery, too
"When it comes to getting back to activity after ACL surgery, it's not just a matter of time," Lang said. "There are a lot of factors. It's partly biology and movement patterns, and then there's the psychological factor: That hesitation around re-injuring the knee or even over-confidence. They might be back to doing things, but not at the level that they want to be."
It can be especially difficult for a youth whose identity is wrapped up in his or her sport. If your child is struggling with feelings of loss after an injury, a mental health professional can help.
The knee might never be the same
Unfortunately, your child could still face knee issues even after he or she is healed after surgery. There aren't any studies that show how long a pediatric ACL reconstruction lasts over the lifespan.
"ACL reconstruction surgery has gotten to be very good now from what it was 30 years ago, but despite that, we do start to see changes in arthritis, usually starting 15 to 20 years after reconstruction," Lang said.
That means that some young athletes could start to develop arthritis in their 30s, putting them on an early path to knee replacement. It's all the more reason to take preventative measures when you can. With the proper training, your child can keep his or her knees healthy for life.