Reducing 2nd ACL Injury Risk

Here is a really interesting paper with some surprising findings.

192 young , highly active ACLR athletes (ave age 21yrs, Tegner Activity Scale level were assessed at 6 months post-op and then followed for the next 2 years to see if they sustained a 2nd ACL injury. The authors wanted to identify if or what possible risk factors that may help explain any 2nd ACL injuries that occurred.

Unfortunately 28% of this group of young athletes had a 2nd ACL injury, with half of them sustaining their 2nd injury within 7 months of returning back to their activity.

One thing the authors found was similar to previous findings (Grindem et al 2016) in that for every month delaying return to activity after 8 months post-op reduced the risk of 2nd ACL injury by nearly 30%.

Grindem et al found that for every 1 month delaying return to sport after 9 months post-op reduced all types of knee injuries by 51%.

What was a little surprising was that those athletes who had higher quads symmetry and higher KOOS-sport score at 6 months post-op assessment were more likely to return to sport before 8 months post-op than those who had lower scores, but they also had a higher risk of 2nd ACL injury.

Mind you at 6 months post-op, neither quads symmetry (75% LSI) or peak torque (1.6Nm/kg) was not that flash either.

It would have been really nice to see what all of these athletes return to sport clearance test results were as current ACLR RTS recommendations have both of these measures sitting at least 90% LSI and 3.0Nm/kg prior to returning to sport following ACLR.

Nevertheless, herein lies the clinical dilemma - stronger, higher functioning ACLR athletes are more likely to be pushing hard to get back to sport and may feel like that they deserve to get back to their pre-injury level of activity.

And to be honest, so they should.

But based on this research, we need to be cautious of good results that we are seeing at 6 months in our ACLR patients and may need to have tough conversations about the risk of returning back to sport earlier than 8 months, vs the rewards of returning back to sport earlier than 8 months.

What do you think about the findings of this paper? What's your stance on returning back to sport based on time post-op?

If you'd like to read the full paper, click on the link here

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