What Is The Injury Risk With RTSport After ACLR?

Return to sport (RTSport) following an anterior cruciate ligament reconstruction (ACLR) is often one of the scariest aspects for both the athlete and the practitioner.  There is a tremendous amount at risk and the wrong decision could have major immediate and future implications.  How do you know when is the appropriate time to return and is the athlete physically and mentally prepared for RTSport?  The psychological impacts that an ACL injury has on an athlete are well documented and addressing this critical for a successful outcome both on and off the field.  In a recent blog (Can I Return to Sports?) we documented the psychology of rehab and return to sports following ACLR.  But what about the physical aspects?  We have heard about accelerated ACL programs that get players back to play much faster than traditional programs, but which one is right?  When is the right time to return to sport following ACLR and what does the research say?

According to the research, there is a significant variance in what is reported as risk with return to sport.  In 2007, Wright et al published a retrospective study that showed only 6% of patients sustained a 2^nd ACL injury within 2 years post ACLR.  Wright’s study contradicts a 2005 study by Salmon et al in which they showed 12% of patients suffered a 2^nd ACL injury in a 5 year retrospective case study.  This issue is further confused by a 2012 study by Leys et al which showed 29-34% of patients suffered a 2^nd ACL reconstruction in their 15 year follow-up study.  This is further complicated by the way that the information is reported.  The above mentioned studies reported incidence proportion estimates instead of incidence rates of patients at risk.  What is the difference?

Reporting incidence rate is a more sensitive measure (closer to actual) because it adjusts for the actual extent of athletic participation.  Since sports participation after ACLR may vary, if you have a lot of subjects who do not return to sport or participate in sport post ACLR, then this would significantly alter your reported percentages. In 2010, Paterno et al published a study that looked at incidence rate and found that 25% of athletes suffered a 2^nd ACL injury to either their ACLR knee or the contralateral knee within the first 12 months of RTSport.   In 2014, Paterno et al had a follow up study to investigate what the incidence rate was beyond the first year after RTSport and ACLR. 

In this latest study, the authors looked at 78 athletes who underwent ACLR and were ready to return to pivoting/cutting sport and compared them to controls.  Each was followed for injury as well as athletic exposures (AE) for a 24 month period.  What the results showed was that incidence rate was 6 times greater for ACL injury when compared to controls.  ACLR female athletes were almost 5 times greater risk for ACL injury when compared to control female athletes.  Female athletes were also more likely to injure their contralateral knee versus the ACLR knee.  Overall, 29.5% of athletes suffered a 2^nd ACL injury within 24 months of RTSport.

These are some alarming statistics.  This is even more alarming if you consider the previous work by Rugg et al.  In this study, they showed that those athletes who had prior knee (not ACL) surgery and ACL surgery were 6.8 and 19.6 fold more likely to sustain a knee injury and 14.4 and 892.9 fold more likely to undergo a knee surgery during their collegiate athletic career.  These same athletes consumed 50% more days on the DL than athletes without prior knee or ACL surgery.  In times in which scholarship dollars are under scrutiny, pressures of producing winning teams is up in combination with high health care expenses and tight budgets, these combined results will mean kids will loose opportunities if they have prior injury.  So, why the high rate of reinjury?

Simple, you don’t ever know if you have addressed the root cause if you don’t assess.  Pure and simple.  What is the root cause?  Some will say genetics, bony structure, hormones and gender.  But are these things that we can change?  No.  What can we change?  Proprioception, strength and endurance. 

Does movement like this occur because of poor genetics or bony structure?  No.  This is an athlete being assessed for RTSport.  This athlete is clearly shifting his weight to his contralateral limb which will clearly put him at risk for a 2^nd ACL injury of the contralateral limb.  This the result of poor training which if it was never assessed prior to return to sport, may not have been identified.  Did he do this prior to his injury?  That part is unknown but you would assume he did not have this shift or at least not to this degree.  Do we see it uninjured athletes?  Definitely!  What we do know is the larger the shift, the more the impact it has on performance and the more of an impact it has on risk.

Does movement like this occur because of poor genetics, bony structure or hormones?  No.  Some would say, how can you say that?  Simple. If this were genetics or any of the other factors, we would not have seen this change with simple implementation of exercises geared to address the root cause.  But they did improve and when we saw changes in these movements across the entire team, we saw dramatic decreases in injury and improvements in performance.   

The research is clear.  Injury rates are rising and when athletes return to sport, they are at a higher risk of a second injury.  The impact on future joint health is significant, future performance is profound and the impact on potential opportunities is devastating.  It is time to do something about!  We can make speculations about, assume we are addressing but unless you thoroughly assess you never know if you are truly impacting the root cause.  In the coming months, ACL, LLC will have a fully automated system using the most advanced research and latest in 3D technology.  The automated Dynamic Movement Assessment™ will provide you with a cost effective way to assess movement in mass that will result in real performance improvement and significant reductions in injury rates.   Know if you are truly changing movement by assessing movement. For more information or introductory pricing, you can email us at drtrent@aclprogram.com.  #DMAOnTheMove   

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About the author: Trent Nessler, PT, DPT, MPT is CEO of A.C.L., LLC and is a practicing physical therapist with 15 years in sports medicine and orthopedics. He has masters in physical therapy and doctorate with focus in biomechanics and motor learning. He is the founder/developer of the Dynamic Movement Assessment™, Fatigue Dynamic Movement Assessment™ and author of a textbook “Dynamic Movement Assessment™: Prevent Injury and Enhance Performance”. Trent is also associate editor of the International Journal of Athletic Therapy and Training and Member of the USA Cheer Safety Council.  For more information, please see our website at www.aclprogram.com.