As more girls play sports, more hurt knees

By Brad Norman
Media General News Service

Published: April 24, 2008

Ahshante Branch was always the exception on the basketball court.

She stood out for all the right reasons.

When exhaustion began to creep in after a grueling practice, Branch always gutted it up and ran another suicide.

When she was outmanned in the post, she pulled down key rebounds among swarms of defenders.

A post player willing to take and initiate contact, Branch sought even tougher competition when she wasn’t playing for West Iredell High School.

She played against older and more athletic males in pickup games, earning their respect regardless of which team won.

She was one of the best players on a Warriors team that would qualify for the playoffs at the end of the 2006-07 season.

Just a junior, Branch had two seasons of great basketball to be played.

In an instant, it was gone.

All of it.

Over the past several years, young females tearing their anterior cruciate ligaments has become an increasingly common occurrence in Iredell County and throughout the nation.

There have been at least 16 serious injuries in Iredell County in recent years.

Branch injured her knee two weeks before the opening game of the 2006-07 season, her junior year, after landing awkwardly during an individual drill.

“It was at practice and the floor had just been waxed,” Branch said. “I was just running down the court, and I guess I came down wrong and it twisted. That’s when I fell.”

Her athletic career hasn’t been the same in the two years since.

It never will be.

Branch was limited to five games as a junior after being diagnosed with a sprained posterior cruciate ligament in December 2006.

The injury never fully healed, and she was forced to play tentatively as her senior year began.

It was the 10th game when that same knee betrayed her again. Branch completely tore her ACL on Dec. 27, 2007, during the R&L Holiday Classic.

That shelved Branch for the rest of the year, and has caused her to spend track season on the sidelines.

“She worked so hard,” West Iredell assistant basketball coach Lee Ann Gatton said. “She went out and played with guys, and the guys were afraid of her. She was probably the hardest worker on our team.

“I hate it for her.”

When Branch played hoops with the guys, she was viewed as an equal, with her tenacity and determination mirroring — or bettering — her opponents’.

But when she stepped onto the basketball court to play with the boys, she also became the exception in a different way.

Branch had a much greater chance of tearing her ACL simply because she is female.

Studies in the American Journal of Sports Medicine and several reports from skilled orthopedists around the world conclude females are four to six times more likely to tear their ACLs than males.

This risk begins around age 11 with injuries occurring most often at the high school level.

A GROWING PROBLEM

The ACL is one of four major ligaments found within the knee and plays an enormous role in preventing hyperextension and providing stability.

The most commonly injured knee ligament, the ACL is like a big rubber band, stretched from the thighbone (femur) to to the shinbone (tibia). When that rubber band snaps — when the ACL tears — the knee becomes functionally unstable.

Female ACL tears have been more scrutinized recently due to the dramatic increase in injuries.

That’s directly due to more female athletes playing sports since the enactment of Title IX.

Title IX, which came into effect in 1972, was the first complete federal law to prohibit sex discrimination in “any education program,” which includes athletic opportunities.

Female athletic participation at the high school level has increased 928 percent since then, according to numbers provided by the National Federation of State High School Associations.

Those same numbers show there were more than 3 million female athletes (3,021,807) at the high school level for the first time ever during the 2006-07 school year.

More girls playing high school sports means more serious knee injuries than ever before.

And more money is being spent to fix those knees.

Multiple national orthopedic doctors estimate a conservative cost of $17,000 for surgery and rehabilitation. With studies showing approximately 40,000 high school females tearing an ACL every year, approximately $680 million per year is being spent throughout the nation on recovery from injuries.

A COMPLETE ANSWER?

Three main theories exist as to why young female athletes are at greater risk, and they are studied both nationally and internationally.

It’s a personal battle for Dr. Timothy E. Hewett, one of the most respected voices in the world when it comes to ACL injuries.

Hewett is the director of the Sports Medicine Biodynamics Center at Cincinnati Children’s Hospital Research Foundation.

He’s also an adjunct associate professor in Rehabilitation Sciences at the University of Cincinnati.

Hewett grew up with six athletic sisters, including one who ruptured her ACL playing basketball.

Her knee grew progressively worse with age, and Hewett has spent the last 15 years studying the ACL and why female athletes are so susceptible to tearing it.

“There is no one definite thing that you can point to as a 100 percent reason for the disparity,” Hewett said in a phone interview with the R&L. “This likely is multifactorial.”

ANATOMICAL DIFFERENCES

One theory is focused on certain anatomical differences between males and females.

Females typically have wider hips, which leads to a larger “Q Angle” — the angle at which the femur meets the tibia.

“The idea is that the greater angle puts greater stress on your ACL,” Hewett said.

Another anatomical difference is the intercondylar notch, on the end of the femur where both the ACL and PCL reside in the center of the knee joint.

The notch is smaller and more A-shaped in girls compared to boys, so when the knee twists during a landing or while cutting, the notch is more likely to shear, and subsequently rupture, the ACL.

HORMONAL DIFFERENCES

Several studies have attempted to link hormonal differences in females to the increase in ACL injuries.

According to the Mayo Clinic and the American Journal of Sports Medicine, fluctuations in estrogen during the menstrual cycle could contribute to ACL tears.

An increased flow of estrogen promotes ligament laxity — in other words, ligaments get looser, said Carl Dunkin, director of Rehabilitation Services at Iredell Memorial Hospital.

When a ligament is looser, a greater chance of injury exists.

“There are studies demonstrating that during the ovulation phase when the hormone estrogen is at its highest, there may be a link to increased ligament laxity,” Dunkin said. “Some studies say females are about three times more likely to injure their ACL during the ovulation phase of their menstrual cycle. But those studies aren’t necessarily conclusive.”

MORAL AND ETHICAL QUESTIONS

Studying hormonal influence is the most controversial theory, especially potential preventative methods, which include taking birth control pills.

“Could you give girls birth control pills and blunt the effects of this? Potentially, you could,” Hewett said. “But it’s very controversial. What do you do? Do you put 11-, 12-year-old girls on birth control pills? There are a lot of ethical, legal and moral issues here.

“And if you tell coaches a girl is more at risk during her period ... it’s kind of the idea of a little bit of knowledge is dangerous, you have coaches pulling girls out of games.”

This theory also opens some sensitive grounds for debate to something that can perhaps be controlled and modified, but not changed.

“I believe in God and his creation, and there are certain things that females were given that are a benefit to them in their development and ability to birth children,” Dunkin said. “There are certain hormones they have that males don’t have that promote their ability to do the things they need to do in childbearing.”

NEUROMUSCULAR DIFFERENCES

The most recent studies, from the American Journal of Sports Medicine to the Midwest Institute of Technology to the British Journal of Sports Medicine, have focused on the neuromuscular differences between males and females.

“It probably is a combination of some anatomical characteristic, some hormonal characteristics, but I think neuromuscular is probably the biggest player,” Hewett said. “And, in addition, it’s the only one that we can really change.”

One crucial aspect of neuromuscular differences involves the way females land after jumping.

“When a female athlete is landing during sports — say when she’s landing from a rebound in basketball — she tends to allow the ground to dictate where her knee is going to go,” Hewett said.

Male athletes allow their knees to flex when landing and simply absorb the force of hitting the ground. Female athletes are far more likely to land with their leg straight instead of flexed, as it should be.

“Instead of just allowing it to flex, they will allow it to abduct — in other words, it goes inward,” Hewett said. “Those muscles are not designed to absorb force with the knee bending inward, and that really is what ends up tearing that ligament.”

Females also primarily use their quadriceps muscles at the front of their legs — as opposed to males, who use their hamstrings muscles on the backs of their legs — when landing and cutting.

Hamstrings help protect the shinbone from sliding too far forward, as does the ACL. When females land from jumps and the quadriceps contract, additional and unnecessary stress is placed on the ACL.

Leg dominance, where one leg is stronger than the other and used more frequently, is a factor because so many ACL injuries occur while landing on one foot.

“When you’re stronger and more coordinated on one leg, that puts both legs at risk,” Hewett said. “Sooner or later, you’re going to have to put a lot of weight or force on that other, weaker leg.”

AFTER EFFECTS

An ACL injury to young female athletes can be devastating, both physically and emotionally.

There’s the immediate loss of an entire sports season plus the potential loss of scholarship funding and lowered academic performance.

The long-term effects are more severe. According to a 2005 study in the British Journal of Sports Medicine, 50 percent of patients with torn ACLs developed osteoarthritis after 10 years.

There are multiple area athletes who have not only torn an ACL, but have been rendered unable to play a particular sport again.

West Iredell’s Branch lost her best two years as a basketball player.

A sensational discus and shot put thrower, she is also going to miss her senior year of track, a time she was going to use to impress potential college suitors.

“I was upset I couldn’t do track or basketball this year,” Branch said. “I was really looking forward to track.”

With a 4.0 unweighted GPA, Branch has been accepted to UNC-Chapel Hill.

She’ll try to walk onto the track team after her rehab is complete, but knows there is no guarantee.

There never is when you’re an athlete.

“It will take me nine months to recover,” Branch said. “I just thought I couldn’t get hurt. I don’t know why I thought that. I just thought it wouldn’t be me.”