Female ACL Injury

IVESTIGATIVE REPORT
Subject: Female ACL injuries and prevention
Thesis Statement: Female athletes should know that they have a higher risk of tearing their Anterior Cruciate Ligament (ACL).

Number of Words: 1,573

Concept and Definition As soon as I was told I had to write an investigative report I knew exactly what my topic was going to be. A year ago I tore my ACL playing soccer. I went through reconstructive surgery followed by six months of physical therapy. About three months after I was released from therapy, I re-tore it while playing in a game. Recently, I have become increasingly aware that the incidence of females who tear their ACL is much higher than that of men. Then I became more curious to why females are more
prone to tearing their ACL. For that reason, my report will expand on differences in anatomical structure, neurological processes, physiological mechanisms and hormonal fluctuation in females, and will further detail prevention methods currently being tested to decrease the occurrence of ACL ruptures in women. What exactly is an Anterior Cruciate Ligament (ACL)? The ACL is a ligament that connects the tibia to the femur. It is one of the most important ligaments in the knee. Ligaments are strong, dense, structures made of connective tissue that stabilize a joint. It serves to prevent the tibia (leg) from moving forward relative to the femur (thigh). The ACL is in the center of the knee. It crosses the PCL (a different ligament in the knee), hence the name, cruciate. The adjective cruciate is from the Latin crux, crucis, meaning "cross". Injuries to the ACL can occur in a number of situations, including sports. The causes of ACL injury have recently been the focus of research. It is the most common knee ligament injury, especially in athletes. Lateral rotational movements in sports like soccer, basketball, and football are what cause the ACL to strain or tear. It is usually injured in a forceful twisting motion of the knee. It also may be injured by hyper extending the knee which is when the femur is forcefully pushed across the tibia such as a sudden stop while running or a sudden change in weight. Other factors contributing to ACL injuries include ground hardness, grass type and cleat type. But one of the other major findings is that women are nearly three times more likely to have ACL injuries than men. And some statistics says that a female soccer player is eight times more likely to injuring her ACL than a male soccer player. The person will feel or hear a sudden pop in the knee. The knee may or may not get very swollen, but the knee will be very unstable so you can not walk and it is painful especially when it is moved after the accident. Over the past decade sports physicians, orthopedic surgeons, trainers, and female athletes have recognized that deceleration non-contact injuries have produced ACL injuries at a disturbing rate in high school and college female athletes. Studies show that women are 2 to 8 times as likely as men to have an ACL injury. In 1995, an article was published in the American Journal of Sports Medicine that found that female basketball players in the NCAA tore their ACL four times more often than male basketball players. In the same study, women who played NCAA soccer sustained ACL injuries twice as often as male soccer players. It is pretty clear that female athletes have a higher risk of tearing their ACL’s rather then men. There are many factors that lead up to why female athletes are more prone to ACL injuries. These include: Hormones, pelvis size, ligament laxity, and quadriceps/hamstring strenth ratio. Therefor, female athletes should know that they have a higher risk of tearing their Anterior Cruciate Ligament (ACL).

Significance and feasibility How do hormonal differences predispose athletes to injury?
It is well known that female hormones effect the composition and structure of a variety of tissues. Females experience large fluxes of hormone levels including estrogen, progesterone, and sometimes relaxin. Because of such great fluctuations in the hormones of females, researchers have linked rate of ACL injury with levels of estrogen. Unfortunately, administering high doses of hormones to human patients poses great health risks, so most studies are conducted on animals. In one study performed by James Slauterbeck, MD, Vice Chairman of Orthopedics at Texas Tech Medical Center and a team physician for Texas Tech, female rabbits were subjected to different levels of estrogen to test for laxity in the knee joint. The ACL load failure rate was measured to be higher in those rabbits that received the estrogen supplements. This supported the hypothesis that females have increased laxity in their knee joints due to increased estrogen levels. The study further concluded that estrogen might play a factor in weakening the strength of the ACL in women. In addition to estrogen, relaxin, though present in small amounts, may also be a contributing factor to ACL tears in females. This hormone, usually present in high amounts during pregnancy, has been detected in trace amounts in ovulating females. Relaxin serves to create laxity in the hip joints during childbirth, but even small amounts found in knee joints might validate
the theory that ACL ruptures in females are linked to joint laxity. Further studies must be conducted to confirm such hypotheses. Further research revealed that there were hormone receptors for estrogen and progesterone on the ACL, signifying that both hormones might manipulate the function of the ACL.
When researchers tested the precursor to estrogen, estradiol, they found that the rate of collagenous substance decreased when a surplus of estradiol was introduced into the system. While not completely supported, the hypothesis stems from the idea that estrogen and progesterone levels are high during ovulation, therefore creating a greater risk of ACL injury. According to T.E. Hewett, oral contraceptive is a way to regulate hormone levels in females and further suggests that the regulation of the hormones can serve to decrease the occurrence of an ACL tear. Researchers suspect that if an ACL injury is related to hormone flux, the occurrence of injury in females will decrease through the introduction of a consistent level of estrogen and
progesterone. While men and women exhibit the same physical features in their lower extremities, the size and positioning of these features differ. One difference between males and females is the width of the femoral notch. On average, men have an intercondylar notch slightly larger than that of females. The larger notch has been speculated to facilitate movement and prevent impingement on the ACL. A study conducted by Lund-Hanssen et al. performed on female handball players concluded that women having a femoral notch width less than 17mm were six times more likely to tear their ACL than men. A narrow femoral notch can inhibit range of motion and pinch the ACL during flexion. Another anatomical feature that contributes to the likelihood of ACL ruptures in women is the way the knee is aligned with the hip. When compared to women’s, the narrow hips of males allow the knee joints to align at a fairly minimal quadriceps femoris angle, or Q angle, with their hips. In contrast, the Q angle in women is much larger due to increased hip width. While increased hip width in females allows for ease in pregnancy and childbirth, a large Q angle causes a tremendous amount of force to be exerted on the medial aspect of the knee joint. When a large load is forced upon the knee during jumps or pivots, the ACL is strained and may not be able to prevent tibial slipping. Unregulated shift tibia can lead to rupture of the ACL. According to 1998 injury statistics from the U.S. Consumer Product Safety Commission, more than 81,600 people injured their knee playing soccer, and 225,800 sustained injuries in basketball. Gymnastics, soccer and basketball are followed by field hockey, volleyball, lacrosse and softball as sports that cause ACL injury in females. Epidemiologic studies estimate that approximately 1 in 3000 individuals sustains an ACL injury each year in the United States. This figure corresponds to an overall injury rate approaching 200,000 injuries annually. The average cost for surgical repair of an ACL tear is approximately $11,500. If all ACL injuries were repaired, the associated expenditure for 100,000 procedures would eclipse $2 billion annually.

Although there is no for sure way of preventing an ACL, there are many training exercises that should be taken into consideration. Balance and strength training are the two most effective ways to prevent a knee injury. Devices such as the stability ball, wobble board, dyna disc are used by top athletic teams. They can be used in conjunction with strength training equipment to create an effective injury prevention program.

Methodology Most of my research has come from the internet and book articles. For the most part, my research has been conducted from my home computer. I also had a personal interview with a local physical therapist. One particular source that I used, (www.ehealthmd.com), was very helpful. It helped me support various topic such as ACL tears, causes, and prevention. My research report focused on the knowledge, statistics, and prevention methods that a female athlete should know. A couple of recommendations include, females should me more aware of the ACL and how it can be torn. Also, female athletes should incorperate strength and balance training with their normal practice routine to help prevent any damage to the knee. Using these suggestions above, female athletes will be able to prevent ACL injuries by making the muscles around the crutiate lagaments stronger and more stable.