Sunday, April 10, 2016

Women's Health: Birth-Control Pill May Cut ACL Injuries in Female Athletes

Erin McLeod kicking soccer ball
Canadian goalkeeper Erin McLeod, shown here in the 2011 World Cup, had to pull out of the 2016 Olympics with an ACL injury. Photo: Thewomensgame

It's long been known that women and girls suffer more injuries to the ACL (anterior cruciate ligament) than males. Estrogen has been thought to be one of the culprits, and a recent study offers more evidence to back up this theory.

Girls aged 15 to 19 who were on the birth-control pill, which reduces estrogen levels, were shown in the study to be less likely to experience severe knee injuries than girls not taking the medication. While the research, conducted at the University of Texas, showed an association between estrogen and ACL injuries rather than a cause-and-effect relationship, the findings are nevertheless intriguing.

Less Estrogen, Fewer Knee Injuries?

"The teens with ACL injuries who were on the birth control pill were less likely to need corrective surgery than girls not taking the pill who had ACL injuries," said an article on the U.S. government website MedlinePlus. "The girls with the highest rates of ACL surgery were 22 percent less likely to be taking birth control pills than those who didn't have an ACL injury."

MedlinePlus also notes "The teens with ACL injuries who were on the birth control pill were less likely to need corrective surgery than girls not taking the pill who had ACL injuries."

The theory of the Texas research is that increased estrogen somehow weakens the ligaments and makes them more susceptible to injury, say the authors of the study. Many athletic girls and women already take birth control pills to have a more regular period and lighter menstrual flow.

Girls and women have many more ACL injuries than male athletes—from twice to eight times as many, depending on what statistics you read. What's more, while the injuries in men occur most likely as the result of contact (as in football or basketball), females often suffer ACL tears in non-contact situations, such as when making a cut in soccer.

Erin McLeod, goalkeeper for the Canadian national team, recently announced she'd have to skip the Rio de Janiero Olympics this summer because of an ACL injury.

Women & ACL Injuries: Possible Culprits

There can be a number of causes to why women are more susceptible to ACL injuries, from the estrogen association the Texas research studied to women's wider hips, a narrower area through which the ACL passes, and greater knee extension. (A WebMD article has a good overview of some of the physical differences between men and women that can possibly explain the increased ACL injuries in women.)

One bit of good news is that doctors have gotten better at treating ACL injuries in women and helping the athletes get back on the field and court. McLeod, the Canadian soccer player, had two previous knee injuries before the current one, and was able to return to professional-level play.

Another hopeful sign is that there's been more focus on helping girls and women prevent ACL injuries, including strength training to build up leg muscles to reduce the strain on knee ligaments. A 2012 study in Sports Health found that two injury-prevention programs "significantly reduced ACL injury rates and improved athletic performance tests."

See the MedlinePlus article on estrogen and ACL injuries in girls, and read an abstract of the Texas study, which was published in the journal Medicine & Science in Sports & Medicine.