ACL Tears: What to Know to Protect Your Knees

An ACL knee injury typically occurs during cutting, twisting or pivoting activities, when the knee is sharply twisted or extended beyond its normal range.

“Most of the time, it’s a non-contact injury involving a sudden change of direction or coming down from a jump after a rebound or a spike,” Dr. Danilkowicz says. 

Contact injuries (like a football tackle) can also cause ACL tears, but they’re less common and often involve additional damage, he adds.  

The “classic” ACL patient is a young athlete, says Dr. Danilkowicz. Sports that involve quick direction changes or jumping — like soccer, basketball and volleyball — carry higher risk. 

Young female athletes are especially vulnerable to ACL tears. Research suggests a combination of causes for this, including differences in anatomy, hormones and movement patterns. 

Increasingly, however, ACL tears are seen in a broader age range.  

“We’re seeing ACL injuries later in life, and older patients are demanding more aggressive treatments,” Dr. Danilkowicz says. “People are staying active longer and want to maintain that lifestyle.” 

Other sports, like skiing, lacrosse, gymnastics, tennis and pickleball, can also cause ACL tears. Some ACL tears can even occur after getting your foot caught while deboarding a plane, stepping off a curb wrong or tripping over your dog, says Dr. Danilkowicz. “Sometimes it’s just a complete fluke.”

One of the most well-known signs is a “pop.” “You won’t always hear it, sometimes the pop is more something you feel,” says Dr. Danilkowicz. “But it is common.” 

Other symptoms include: 

• Rapid swelling 
• Severe pain (especially if attempting to bend, straighten or bear weight on the knee) 
• Instability or the knee “giving out”
• Reduced motion 

Interestingly, some people can still walk after the injury, once the inflammation and swelling go down. “Other structures can compensate,” he says. “But when you try higher-level activities, that’s when you notice the instability.” 

Treatment depends on your age, activity level and goals. Often, especially for young athletes or active individuals, ACL surgery is the best option.  

“In younger patients, the standard is an autograft – to reconstruct the ACL using your own tissue,” says Dr. Danilkowicz, who usually recommends this for patients 40 and under. Graft options include the hamstring, quadriceps and patellar tendons. “Your own tissue is more robust when young and has a lower retear rate over time.” 

In older patients, an allograft (donor tissue) is used, which usually results in a less invasive surgery and an easier recovery since tissue isn’t taken from a second site.   

Sometimes, non-surgical treatments are sufficient for partial tears or less-active older individuals. In these cases, says Dr. Danilkowicz, patients can try physical therapy to strengthen surrounding muscles.  

Even then, ACL surgery may ultimately still be needed

For Abigail, staying active is essential. From early morning runs before long days as a school principal to weekends on the water with her children and winters spent skiing, movement helped her manage stress and stay connected to the people and activities she loved.

Everything changed after she tore her ACL. Although she underwent reconstructive surgery and rehabilitation, she never felt her knee was fully stable and suspected the surgery had failed. Months turned into years and, despite her efforts to continue rehabbing, she knew something still wasn’t right.

Frustrated and seeking answers, Abigail turned to Emory Healthcare and Dr. Rick Danilkowicz, where further testing revealed that her initial ACL reconstruction had indeed failed. After undergoing revision ACL reconstruction at Emory, she quickly noticed improved stability and, more than a year later, has returned to many of the activities she enjoys. Her advice to others: Stay committed to rehab, listen to your body, and “trust the science — but also trust yourself.”