Tilly Payne caught the ball, jumping to a sudden stop. As she leaned on her right knee, it collapsed and she fell onto the basketball court.
Payne, a junior forward for Columbia College, had torn her anterior cruciate ligament Jan. 4.
“At first, I didn’t think it was my ACL because I walked off of the court,” Payne said. “And then when I went to the locker room, it got really swollen. After that, I couldn’t walk on it.”
The ACL, one of four ligaments that stabilize the knee, connects the tibia to the femur, crossing the center of the knee. It is most commonly injured in basketball, soccer, football and volleyball. The most common actions that cause the tear are planting and cutting, decelerating or hyperextending the knee.
“The reason it gets injured is usually from non-contact reasons,” Dr. Christopher Farmer said. “Football players can do it, if they get tackled the wrong way and their body gets in a strange position. But even in football, a lot of times, it’s the guy who makes the catch and turns to run down the sideline.”
Although many athletes tear their ACLs, the NCAA has found that women do more often than men. In basketball, female players are almost four times as likely to do so than males.
According to Farmer, who works in the Sports Medicine Department at the University of Missouri, the NCAA began collecting data about injuries during the 1980s. Since the Title IX bill was passed in 1972, there have been more NCAA sports for women, and as a result, more female athletes and more injuries.
“You’ve got a larger proportion of females playing sports now than there were 20 years ago, but a disproportionate amount of those are tearing their ACLs more often,” Farmer said.
The NCAA Injury Surveillance System recorded only four ACL tears among Division I male basketball players last season, and all occurred in practices.
In contrast, there were 15 ACL tears in Division I female basketball players. Six occurred in practices.
In a reverse of the national trend, the Missouri men’s team has had two ACL tears in the past five years, and the women’s team has had one, which was five years ago.
In the past five years, Columbia College has had three ACL tears in its men’s basketball program. In contrast, the women’s program has had three tears in the three years it has operated.
Junior Mindy Mitchem, a forward at Columbia College, tore her left ACL when she hyperextended her leg during a game last season.
“I was driving to the basket and did a jump shot, and I actually got hit from behind,” Mitchem said. “My leg hyperextended forward and the ACL just popped. I went down and was screaming. It was my first injury, so I didn’t know what to expect.”
Although most doctors and athletic trainers are aware of the higher risk for female athletes for this injury, no one has identified the exact reason.
There are three primary theories, and the most common is the differences in muscle use between women and men.
“We’re shaped differently,” Payne said. “We’re just not as strong.”
Male athletes develop their hamstring muscles much more quickly than females. According to Dr. Farmer, women tend to develop the quadriceps first, which is the muscle on the front of the thigh.
“The front of the thigh muscle is kind of the antagonist to the ACL,” Farmer said. “When it contracts, it pulls in the opposite direction that the ACL wants to go.”
Because women develop this muscle more quickly than others, particularly the hamstring, it could cause them to tear their ACLs more often.
Hormonal differences, particularly relating to menstruation, is another theory that is gaining medical credence. It has been found that the ACL has estrogen receptors in it, which means that changes in levels of estrogen could affect its strength.
Last year, the Health Center at the University of Connecticut introduced a study to determine whether more ACL injuries occur during the female athlete’s menstrual cycle. Results from this study have not been released.
In 2001, the National Athletic Trainers Association Research and Education Foundation released observations from a similar, though smaller, study that found that most women tore their ACLs at the same point in time in their menstrual cycles.
Conducted at Texas Tech University, the study examined 37 female athletes, 25 collegiate and 12 in high school, who had torn their ACLs. Twenty-six of the 37 were injured during the beginning of the follicular phase of the menstruation cycle, which is when levels of estrogen have risen. One effect of this hormone change is that the ligaments become looser, and easier to tear.
“I was told that most women tear their ACL about the time that they’re about to start menstruating, or when they are menstruating, and I was actually about to start my menstruation,” Payne said. “So I actually thought that was kind of cool, that that was how it came together.”
A final theory relates to basic differences in bone structure and anatomy. According to Farmer, women tend to be more knock-kneed and also have lower arches in their feet. Females also have different proportions from their pelvis to the kneecaps than men.
“When females land from a jump, their hip tends to be more flexed, and their knee a little straighter than guys’ are,” Farmer said.
This puts more impact on the knee, potentially causing more injuries.
While all of these theories are supported with medical observations, none has been the proven cause.
“Everybody’s made these observations, but no one’s ever really proven that that’s definitely the one thing that does it,” Farmer said. “It’s probably a bunch of things all at once.”
Because the cause is uncertain, doctors are unsure what to tell female athletes to try to prevent an ACL tear. Proper conditioning and attention to muscle development, as well as proper stretching before exercise, are recommended as basic precautions. Knee braces are also available, but exactly how much they help is unknown.
“It was really a struggle because you expect to bounce back afterwards and be the same player,” Payne said. “That was one of the first things I thought about when I tore my ACL. I thought ‘I’m never going to play the same way again.’”
Once torn, the ACL cannot be repaired, but surgery is available to replace the torn ligament. A piece of the patellar tendon, which is removed from the kneecap and sewn into where the ACL should be, is the most common replacement. According to Farmer, it is unlikely that doctors will try to learn how to repair the ACL because the replacement works so well.
“If you have it reconstructed, which is a pretty common surgery these days, about 85 to 90 percent of those return to play at the same level they were at before,” Farmer said.
After the surgery, the athlete begins rehabilitation, which usually takes four to six months, depending on the level of training available and if other parts of the knee were injured.
“You do a lot, a lot of leg lifts, quadriceps, a lot of skimming ice, and basically that over and over again,” Payne said. “The next week, they’ll take it up a notch. You might do some exercises, or you’ll do something different. They’re starting to get a lot more aggressive with the rehab.”
Payne said that her doctor at Columbia College did not make her wear a knee brace, which she thinks helped her mentally. She said it helped convince her that she was uninjured and capable of playing again.
“They tell you that your new ACL is stronger than your old ACL, and that helped me as far as mentally knowing that I’m probably not going to tear my new ACL and to just go out and play normally,” Payne said. “Every day at practice, I’m getting better.”
Payne’s surgery was Jan. 28, 2003. As she nears the one-year anniversary of her injury, she said she is seeing the affects of her injury.
“My other knee is starting to suffer a little bit because I’m getting tendontitis in it for compensating for my bad knee, but they’re starting to even out more,” Payne said. “They say it takes up to a year for you to get back to normal, so hopefully all the aches and pains will go away with the weather.”