Anterior Cruciate Ligaments
It comes unexpectedly and when it’s least convenient. Really, there’s no good time for it. It’s challenging to deal with in every way: physically, mentally, emotionally, spiritually. It’s the bane of every athlete’s existence and passion. Injury.
Injuries have the power to end an athletic career at worst and inhibit an athlete’s capabilities at best. As most of us have seen in professional sports, they span the whole body, from brain concussions to sprained ankles.
Here, I’d like to discuss one injury in particular: ACL tears. Growing up, I was a slalom and giant slalom ski racer, and in my early teens, I began to participate in more competitive races. In 2013, when I was 14, I tore my right ACL training for a ski race. This resulted in an immediate removal surgery and a later reconstruction surgery within one year, the loss of the rest of that ski season and the next, and the end of my competitive racing career. However, it led me to find a new passion: race coaching.
I started working with the younger kids on my team as their coach rather than as their teammate. I sought to share my own passion for the sport and instill safe, strong skills in my athletes. But 3 years later, when I was 17, I tore my left ACL and meniscus on my day off from work. One of my younger athletes saw it happen, and unfortunately heard the stream of profanities I couldn’t help but spew as I felt it tear. ACL tears hurt.
In professional athletes, they used to mean the end of a career, but with modern technology, they can opt for an arthroscopic surgery combined with a team of physical therapists dedicated to their recovery. Procedures and teams like this allow for athletes like Lindsey Vonn and Tom Brady to return to pro skiing and football within a season. When a person’s income depends on a sport, it is imperative that they recover quickly, and they will usually be more driven to recover in the least amount of time possible.This is what often happens with star athletes.
Competition in most sports bottlenecks during the early teens, separating the star athletes with the potential to go pro from the recreational athletes. For this reason, such injuries often force developing athletes to quit their sports — which was the case for me. During the consultation process with my surgeon in 2013, I learned that ACL injuries in particular affect more women (especially between the ages of 12 and 18) than men in the ACL tear-prone sports. Such a statistic put me in the target demographic for the injury so I’d like to ask why. Why are teenage females more likely to tear their ACLs in ACL tear-prone sports than other demographics?
I should begin by defining ACL tear-prone sports and describing the demographic to which I will be referring. First, the anterior cruciate ligament, more casually known as the ACL. This ligament is one of four vital ligaments in the knee. Physically it’s the smallest, but carries the greatest load. The ACL is responsible for knee stabilization during rotational motion (Souryal).
This means that during twisting and lateral motions, this ligament is put under the most stress and bears the most responsibility. Dr. Tarek O. Souryal, head team physician of the Dallas Mavericks, diplomate of the American Board of Orthopedic Surgery, and assistant clinical professor at the University of Texas Southwestern Medical Center explains that, “The most common sports in which we see ACL tears include soccer, basketball, football, and tennis,” because, “The most common mechanism of injury is non-contact and caused by cutting.”
This cutting can occur when someone plants their foot but their body’s momentum carries them forward or sideways. Planting, kicking, jumping, stopping and twisting motions all contribute to this detrimental motion in non-contact instances. When they occur, the lower part of the leg stops with the foot while the upper part continues with the body, causing a laceration at the knee joint.
Sports with rotation (like soccer, basketball, volleyball, skiing, etc.) thus become the “ACL tearprone” sports because their common motions lend themselves to ACL tears. The demographic to which I will be referring includes female athletes between 12 and 18 who participate in these ACL tear-prone sports.
The logical next step is to question why this particular demographic is at a heightened risk. Anatomical geometry plays a large role. In the knee exists the femoral intercondylar notch and in the notch exists the ACL. The Sports Health Journal article Risk Factors for Anterior Cruciate Ligament Injury, co-authored by Helen C. Smith and other doctors, explores several subsequent studies looking at ACL tears and compiles their findings. In general, the conclusion has been drawn about the relationship between the notch and the ligament on the basis that, “As intercondylar notch width decreases, an increase in ACL injury risk is observed” (Smith et al.). This occurs because as the ligament’s home narrows, it has less room to move around when the rest of the body moves. With this decreased internal flexibility comes the increased chance that the ACL will tear when it moves. Dr. Souryal’s study was one of those compiled in the Sports
Health Journal analysis; his study finds that people whose notches are particularly narrow have 26x greater risk of tearing their ACL. Furthermore — and this is where our why begins to find an answer — females’ anatomy includes, “…a proportionally narrower notch…” than their male counterparts (Souryal). This finding was consistent with my surgeon’s analysis of the causes of my own injury as well. During the first reconstruction surgery, she widened my notch, but the other one remained narrow, which contributed to the second tear. Both notches were widened during reconstruction to allow for more ligament flexibility, reducing the risk of future tears.
While this is not mentioned in Souryal’s or Smith’s studies, another anatomical difference discussed prior to my operations increases this injury’s prevalence in our target demographic. Teenage girls have developing bodies, and at this age, their hips are usually more developed than their legs. The combination of pressure from athletic activity and pressure from wider hips on the knee joints can often be too much for not-quite-developed legs, especially if the athlete is not at super-peak strength. Since males don’t have such exaggerated hip development, teenage boys are less at risk for this factor; they don’t need to worry about the added pressure on their knees that comes from wider hips.
Further exacerbating this issue is one particular notion our society instills in young kids. From a young age, boys experience more encouragement to participate in sports than girls. Most people who grew up in an athletic environment can attest to this phenomena. Regardless of the reasons why, young girls tend to focus on other things during their childhood (like dolls, coloring, and painting their nails — this was definitely the case for me). This causes girls to have less muscle mass in their legs and less neuromuscular coordination, simply because they don’t have as much exposure to playing sports than boys. In fact, Dr. Souryal considers this issue in his analysis by explaining that boys, “may develop better neuromuscular coordination and therefore are somewhat protected as they get into high school and college,” because they are encouraged to play sports at a younger age. This means that when girls begin sports in their late youth, then, they have a higher risk for injury because they have had less exposure.
These factors culminate to increase the risk of ACL tears in females between the ages of 12 and 18 in ACL tear-prone sports. Of course, there are other factors that must be considered, like the level of competition. Athletes who play varsity basketball in high school are obviously going to be more at risk for this injury that people who shoot hoops for half an hour on Saturdays, almost regardless of demographic. All else being equal, though, the female anatomy lends itself to more ACL tears in teenagers.
I’d now like to ask, why does this even matter? Who does this affect? Perhaps the clearest answer to this question is athletes. Digging deeper reveals that knowledge about these kinds of issues can allow women to make more informed decisions about their own bodies. Most people can agree that injuries are bad. Knowing this kind of information lets women decide whether they want to train differently to avoid ACL tears, whether they want to take preventative measures, or whether they want to compete in the sports that increase their risk. The recovery process is difficult and painful. It takes a long time and tests a person in ways they didn’t know they could be challenged. If there is any way a person can avoid an ACL tear, they should. Armed with the information that they are more vulnerable and what exactly makes them more vulnerable can give women the power to prevent these injuries and others in their bodies. One preventative measure that may be possible in the future is the surgical enlargement of the intercondylar notch in individuals who are otherwise healthy. This would allow for more knee flexibility so when an athlete twisted, less force would be placed on their ACL.
Here, we’ve explored the reasons why ACL tears are particularly prevalent in teenage girls in tear-prone sports, why it matters, who it helps, and what we can do. Hopefully an increased awareness helps prevent the future proliferation of ACL tears in athletes.
Smith, Helen C. et al. “Risk Factors for Anterior Cruciate Ligament Injury: A Review of the Literature — Part 1: Neuromuscular and Anatomic Risk.” Sports Health 4.1 (2012): 69–78.
PMC. Web. 16 May 2017.
Souryal, Tarek O., M.D. “ACL Injury, ACL Tear, ACL Surgery.” ESPN Feature on ACL Injuries,
ACL Tear, ACL Surgery, ACL Injury, Dallas Texas Sports Medicine, Dallas Mavericks.
Texas Sports Medicine, n.d. Web. 16 May 2017.