Real grass vs. artificial turf
It would be bad if losing a player to a torn ACL hurt a team's playoff chances. It would be worse for two teams to suffer these critical knee injuries in the same game. Even worse would be the possibility that those devastating losses could have been prevented in the first place.
Was the playoff battle between the Washington Redskins and the Seattle Seahawks an example of such a worst-case scenario?
Most of the focus from that fateful game has centered on the injury to Redskins quarterback Robert Griffin III.
While most of the controversy focused on whether he should have been cleared to play, several analysts did point out that the conditions at FedEx Field could have been at least a contributing factor.
In that same game, however, the Seahawks lost their best pass rusher, defensive end Chris Clemons, to a serious knee injury. That injury turned out to be a torn anterior cruciate ligament and meniscus. Clemons' agent blamed the field conditions for his injury.
Everyone watching could see that the grass field was in poor shape. Mike Florio of Pro Football Talk observed, “The natural grass at FedEx Field is, by January, neither natural nor grass.”
Could the ACL injuries of RGIII and Chris Clemons have been prevented if the Redskins played their games on FieldTurf instead of grass?
FieldTurf is one of several varieties of a newer generation of artificial turf. Unlike earlier forms, which were essentially carpet laid on top of concrete, these newer “infill surfaces” were designed to more closely replicate natural grass. They consist of long polyethylene fibers woven onto a mat with either rubber or rubber and sand between the fibers.
While FieldTurf and similar infill turf surfaces are expensive to install, they have minimal maintenance costs. Plus they provide a surface that remains consistent and doesn't wear down as the season progresses or the weather worsens.
While many players prefer FieldTurf, others fear possible injuries playing on it. Former Jets nose tackle Kris Jenkins believes FieldTurf might have caused his two knee injuries. Steelers quarterback Ben Roethlisberger argues that it is “a great field, but FieldTurf is just killing guys because they can't get their feet out of the ground.”
Two different studies published in 2012 lend credence to players' concerns over injuries. Elliott Hershman and others reviewed NFL injury data from games played between 2000 and 2009. They found that the injury rate of knee sprains as a whole was 22 percent higher on FieldTurf than on natural grass. Rates of ACL injuries were 67 percent higher on FieldTurf.
Likewise, Dragoo and other researchers reviewed the NCAA Injury Surveillance System for college football injuries between 2004 and 2009 to attempt to identify risk factors for ACL tears. They observed that rates of ACL tears were higher on artificial turf than on natural grass. When they isolated infill turf surfaces, such as FieldTurf, the ACL injury rate was significantly higher than on natural grass.
It is important to point out that one study looking at injuries at eight high schools did show a higher rate of knee injuries on grass. Also, none of these studies offer answers as to exactly why these injury rates differ.
Does the interaction between cleats and artificial turf differ from that between the cleats and natural grass? Do rainy, hot, or cold weather conditions have an effect?
We might never know if FieldTurf or a similar artificial turf field would have prevented the injuries to RGIII or Chris Clemons. Much more research is needed regarding field surfaces, shoe design, and other variables to better prevent these injuries. But for now, we can at least presume that FieldTurf isn't a cure for ACL injuries.
Dr. David Geier is an orthopaedic surgeon and Director of MUSC Sports Medicine. For more information about football injuries and other sports medicine topics, go to his blog at drdavidgeier.com.