For young athletes returning from ACL surgery, how risky is it to return to sport before 9 months?

Research Reviewed: Young Athletes Who Return to Sport Before 9 Months After ACL Reconstruction Have a Rate of New Injury 7 Times That of Those Who Delay Return (Beischer et al; JOSPT, January 2020)

This week’s research paper investigated whether young athletes - in this case ranging from 17 to 26 years old - who underwent ACL reconstruction and returned to sport had a higher risk for suffering another ACL injury based on 1) time to return to to sport, 2) symmetrical muscle function, and 3) symmetrical quadriceps strength.

The methods

The researchers used a rehabilitation registry to find athletes within the aforementioned age range who had ACL reconstruction, had returned to sport, and suffered another ACL rupture. This registry also included five tests of muscle function (two strength tests and three hop tests).

Overall, 159 athletes (mean age of 21.5 +/- 4.4 years, 50% female) were included.

The key takeaways

The researchers found three main points:

• Young athletes returning to knee-strenous sports before nine months after ACL reconstruction resulted in a 7x increased rate of suffering another ACL injury

• Symmetrical muscle strength prior to returning to sports was not associated with new ACL injury

• Symmetrical quadriceps strength prior to returning to sports was not associated with new ACL injury