David Chao, MD: What Is Causing All The ACL Tears?

There were seven confirmed anterior crucial ligament (ACL) tears after this brutal NFL injury week: Saquon Barkley, Courtland Sutton, Nick Bosa, Solomon Thomas, Bruce Irvin, Tavon Young and Marquise Blair. Many are questioning if the lack of preseason games is to blame.

The answer is complex.

There have actually been fewer ACL tears so far this season compared to most other recent years. There have been 19 ACL tears this year league-wide so far through Week 2  and the league average the last 5 years during the preseason alone is 25.

ACL can be considered an acclimation injury as tears happen at over twice the rate in the preseason versus in the regular season. Consider a six-week training camp and an average of 25 tears gives us a rate just over four per week. Across a 17-week regular season, the average of just under 30 ACL tears gives us a rate of under two per week.

The spike of ACL tears from this past Sunday is in part bad luck but in part seems to be the shifting of the higher rate of preseason ACL tears into the regular season. Given the lack of an offseason program, preseason games and live practice time, it actually lowers the number of ACL tears for training camp but there seems to be a shift into the early regular season.

Even with the spike in Week 2 of ACL tears, balanced against a relatively healthy Week 1 that puts us at the preseason rate of about four per week. With the pandemic altered training camp and lack of preseason games and practice, the season so far has us headed towards a lower than typical total of ACL tears so far.

There is a small sample size so no firm conclusion should be drawn but the evidence does not prove that lack of preseason games has led to an overall increase in ACL tears.