How successful is ACL reconstruction, really?

/ OPA/

Anterior cruciate ligament (ACL) reconstruction...as good as it is, it is still not perfect.  ACL reconstruction is one of the most successful procedures we have in orthopaedics, that is, depending on the type of patient...

Surgeons will inform patients that there is about a 85-90% success rate of ACL reconstruction, and we're not lying.  This means that a HUGE percentage of people who undergo an ACL reconstruction are happy with the outcome and able to return to the same level of activity they participated in prior to the injury.  However, a LOT of people probably choose to have their ACL reconstructed when in reality they didn't need to have the surgery.  There are patients with ACL tears who rarely participate in activities that involve rapid acceleration, rapid deceleration, change of direction, pivoting, jumping, landing or cutting (these are the kinds of activities that require an intact ACL in order to have a stable knee).  People who don't have much exposure to these activities may not need an ACL.  If that particular patients undergoes an ACL reconstruction, then they are pretty much assured a perfect result; a complete return to pre-injury activity, and an exceedingly low rate of graft re-tears.  Therefore, the inclusion of a lot of less athletically-inclined patients in our outcome studies of ACL reconstruction make our results look exceptional.

Now, let's look at the results of ACL reconstruction in "high risk" populations with frequent activity exposure (4-5 days of participation per week).  By high risk, I mean folks who regularly engage in cutting sports, rapid acceleration/deceleration, jumping, landing and twisting.  In this instance, our results don't look so great:

  • A 2012 article in the American Journal of Sports Medicine looked at high school and collegiate football players who sustained an ACL injury and the likelihood that they returned to play.[i]  In the study, only 63% of high school and 69% of collegiate players actually got back to competition.  More concerning was the fact that the players' ability to play at the same level of ability was even less impressive:  50% of players at "nonskill positions" (e.g. linemen) were able to play at the same level, as opposed to only 41% of "skill position" players (defensive backs, running backs, etc).  That's sobering when compared to the 85-90% success rates I noted above.
     
  • The same trends hold true for ACL injuries in soccer players.  A study performed by the MOON group (Multicenter Orthopaedic Outcomes Network) compiled data from multiple high-level institutions and demonstrated that only about 72% of 100 ACL-injured soccer players were able to return to competitive soccer.[ii]  Factors associated with a higher likelihood of return were younger age and male sex.  Furthermore, 20% of females and 5.5% of male players required further ACL-related surgeries, and only 35% of the ACL-injured players were still participating in soccer over the long term (an average of 7-years later).
     
  • Even at the pinnacle of sport in the United States, the National Football League, where players have access to the best possible care and rehabilitation, statistically only about 63% of players are able to return to league play after an ACL injury, and this is highly influenced by the proven ability of the player.[iii]  Players who have more than 4-years of experience in the league and those who were low draft picks had the best chances of return (after all, the teams have a lot of time and money invested in them) but even those odds are not so great. 

So depending on how you spin the numbers, the results of ACL reconstruction are somewhere between "better than average" and "exceptional".  In short, an ACL reconstruction is an awesome surgery in the same way that a Ferrari is an awesome car; It's pricy, it's trendy ("everyone" is getting their ACL fixed), it requires maintenance and the more it gets used the more risk for damage (i.e., re-rupture).

[i] Mccullough, KA, et al. American Journal of Sports Medicine. 2012 Nov;40(11):2523-2529.
[ii] Brophy, RH, et al. American Journal of Sports Medicine. 2012 Nov;40(11):2517-2522.
[iii] Shah, VM, et al. American Journal of Sports Medicine. 2010 Nov;38(11):2233-2239.