Understanding ACL Tears

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Odds of winning the Powerball lottery: 80 million to 1.

Odds of becoming President of the United States: 17.5 million to 1.

Odds of hitting a hole-in-one: 26,500 to 1.

Odds of a female athlete tearing her anterior cruciate ligament (ACL) compared to a male: 5.5 to 1.

That's right. Female athletes are more likely to tear their ACLs than guys.

According to Dr. Edward Laskowski, physical medicine and rehabilitation specialist and co-director of the Mayo Clinic Sports Medicine Center, in Rochester, Minn., a number of factors contribute to this sad reality. "The ligament itself is a bit shorter in females, and the notch it rides in is narrower," Laskowski says. "There may be some hormonal influences, also, but these have not been definitely proven. We do see girls sustaining tears five to six times more commonly than guys—especially at the high school level."

Located in the interior of the knee, the ACL connects the thigh bone to the shin bone and provides front-to-back stability for the knee. High impact sports that involve a lot of jumping, pivoting and sudden changes of direction can cause an ACL to tear. " Typical scenarios," Laskowski says, "are when a soccer player is running down the field, plants, pivots and changes direction quickly, or when a basketball player lands awkwardly coming down from a rebound."

Several reconstruction options are available for ACL tears. The two most common involve making a new ACL from the patella tendon or hamstring tendon. The patella tendon connects the kneecap to the thigh bone. After removing the middle third of that tendon, the doctor uses it to create a new ACL. To create an ACL from a hamstring tendon, the doctor loops and inserts the tendon into the knee joint.

Although success rates for both surgeries are high, rehab following both is extensive, ranging from six to nine months. "We try to establish full range of motion about the knee as soon as possible, especially focusing on fully straightening it. The earlier we get full range, the earlier we can institute more exercises," Laskowski says. "Being consistent with exercises is key. People who aren't compliant with the exercises see some problems."

Because ACL tears take an athlete away from the game for so long, Laskowski incorporates sports counseling into his surgical reconstruction program. The counseling provides psychological support and assistance to athletes in rehab to get them back into their sport. "Tearing an ACL can be a devastating injury, because it's not one where you're back in a week or two—it takes a long time to get back," he says.

"The key is to look at the short and long term. Short term means the six to nine months when the athlete isn't doing what she wants. But for the long term, we want to give the best knee possible to prevent instability of the knee, which can lead to cartilage damage and arthritis at an early age."

Stop what you're doing. Stand up. Jump. Watch your knees as you land. Did they remain forward or collapse inward?

If your knees collapsed, you might have a condition called medial rotational instability of the knees. Studies have shown that people with this movement pattern are more likely to tear an ACL. Lucky for you though, other studies reveal that learning how to jump and land properly eliminates this greater risk.

To help prevent serious knee injury, experts have been able to teach proper body mechanics to people with collapsing knees. Two teaching cues are jumping up straight as an arrow and landing light as a feather.

Contact an athletic trainer, physical therapist or sports medicine physician if your knees are prone to knocking each other. He or she will help you correct your landing form.

For more information on the ACL please see the STACK ACL Guide.

Photo Credit: Getty Images // Thinkstock