Youth ACL injuries appear to be on the rise. Adult ACL injuries have been the hot topic in decades of research in an attempt to reduce the frequency of these injuries, especially in sports.  But why the recent increase in ACL injuries in kids?  According to Moksnes et al 2013, most ACL tears come fromAlpine skiing and soccer making up 73% of injuries in that study.  As this was an international study, American football wasn’t available for the population to study. Mix this finding with results of a Mansson et al AJSM 2014 study who found that the cause of injury was 55% contact and only 21% non-contact.  Almost the exact opposite of mechanism in adult injury:

So are we setting up our children for life changing injury based on the sports they chose (or we chose for them)?

In the long term, patients who were adolescents at the time of their ACL reconstruction revealed significantly more radiographically visible OA changes in their operated knee than in the non-op knee. Rarnski et al 2013 investigated Anterior Cruciate Ligament tears in children and adolescents and found in their Meta-analysis 13.6% of reconstructed felt instability compared to 75% of non-operative and meniscal tears were 12x more likely in non-op group (35.4 vs 3.9%). 

Anderson and Anderson 2014 AJSM stated that the independent risk factors for incidence of lateral meniscal tears were younger age and return to sports prior to surgery.  Subjects with one (1) incident of instability had a 3-fold higher odd of a high grade lateral meniscal tear.  And chondral injury factors were instability episodes and increased time to surgery. Subjects with meniscal injuries were more likely to have chondral injures in the same compartment. Preservation of the menisci may theoretically reduce the changes of articular cartilage degeneration and the additional risk of OA.

However, there have been studies that have found that the prevalence of meniscus injuries at only 29% at 3.8 year follow up and 88% reported returning to monthly cutting and pivoting tasks at school.  It should be of strong note that those individuals who were non-operative were instructed in a treatment algorithm and 1/3 changed their activity at F/U. Somewhat deceptive to the reader of only the abstract.

Surgical Reconstruction Options

From a surgical standpoint, social, psychological, demographic and age dependent factors all need to be considered in every case.  And currently there is no consensus in literature about transphyseal ACL recon, physeal sparing, or non-op. Although likely that physeal sparing early reconstruction is probably better in terms of incidence of menisci and chondral injury compared to delayed.  The return to sport and decline in participation is obvious and substantial 2-3 years non-operatively in most research studies on this topic.

According to a 2013 study, children and adolescents who undergo early surgical reconstruction after suffering a complete tear of the anterior cruciate ligament (ACL) have much better outcomes than those who delay surgery or never have surgery at all.

Reviewing data from six studies comparing operative to nonoperative treatment and five studies comparing early to delayed reconstruction, researchers at the Children's Hospital of Philadelphia found that patients in the nonoperative or delayed group were 33 times more likely to have persistent instability in the injured knee than those whose ACL tears were treated surgically.  

In terms of return to play, athletes who had early ACL reconstruction were 91.2-times more likely to return to activity at the athlete's previous level of play than those who did not have surgery, who were also much more likely (67% versus 4%) to subsequently suffer a tear of the medial meniscus. “Our results suggest that patients are much more likely to return to sports at their previous level of athletic ability after early operative treatment as well as have fewer instances of instability" of the knee or meniscus tears, writes lead author, David E. Ramski, BS, BM, of the Georgetown University School of Medicine.  

The availability of surgical techniques that spare or avoid the growth plates when reconstructing the ACL in skeletally immature patients, and limited evidence that surgery arrests the growth of such plates, may assuage some of the concern related to premature growth arrest or deformity with early reconstruction, the current studies conclude that the data favor early ACL reconstruction, particularly for active young athletes who wish to maintain higher levels of physical activity.  

Based on concerns that surgery might damage growth plates at the end of the tibia and fibia in such skeletally immature patients, the optimal initial treatment for ACL injuries in children and adolescents has not resulted in a clear consensus for initial nonoperative treatment or operative reconstruction. Whether a study will lead to the development of a consensus that early ACL reconstruction is the optimal treatment remains to be seen. 

Parents should understand that early reconstruction of the ACL, before any other damage to the knee, gives their child the best chance of a good outcome in the future. Once other structures in the knee are damaged, the final outcome may not be as good, no matter what the surgeon does at the time of reconstruction. 

Some of the difficulty with non-oping kids is the ability to control their activity.  Telling children to simply stop moving a certain way is a near impossible challenge. Most current research studies strongly imply that delaying ACL surgery and reconstruction puts an athletically or even a normally active teenager at significant risk for re-injury, and for injury to other structures in the knee.  

As detailed in a recent study in the Journal of Bone and Joint Surgery the indirect costs (e.g. lost wages, productivity, and disability) associated with an unstable knee after an ACL tear are substantial. Researchers at KNG Health Consulting in Rockville MD found that ACL reconstruction was less costly (a cost reduction of $4,503) and more effective in terms of quality of life compared with rehabilitation because of the higher probability of an unstable knee associated with rehabilitation.  

In the long term, the mean lifetime cost to society for a typical patient undergoing ACL reconstruction was less than half that for rehabilitation ($38,121 versus $88,538).  

The finding demonstrated that access to ACL reconstruction is critical to optimal societal health-care delivery.

So what choices do we have as rehabilitations professionals for youth clients with ACL injuries? Unfortunately, surgical medicine continues to prove that what we surgically correct now, might not be our best option, or even what we should have done a decade later in hindsight. But surgical medicine also continues to advance almost annually. Preservation of the cartilage structures should lead to the most optimal outcome in the long term and reconstructing the ACL as soon as possible appears to appeal to common sense from a biomechanical model stance. In my biased opinion, prevention must be the first line of defense.  But according Mansson, youth injuries at much more likely to be from contact than non.  Specific functional activity training can’t control all of that.  Proper coaching and conditioning might aide the cause. Cessation is an option as well.  But pulling kids from sports to avoid getting hurt is not an option many parents or coaches will likely consider.  After all, we are all superman until we get hurt…. Or as Iron Mike Tyson would say “Everyone has a plan until they get hit.”

This leaves this with a real dilemma for this injury in this population. 

Hopefully we find some answers soon. 

 -Eric M. Dinkins, PT, MS, OCS, Cert MT, MCTA, CCI