During a preseason soccer match in 2017, University of Kansas player Mandi Duggan suddenly crumpled to the ground, and the team’s athletic trainer had to pick her up and carry her into the training room. Somehow, she knew exactly what had happened — she had damaged her anterior cruciate ligament, or ACL.

“It was such an odd feeling, and I knew what had happened right away, even though I’d never torn my ACL before,” Duggan said.

The ACL, a ligament located in the center of the knee, connects the femur, or thigh bone, to the tibia, or shin bone. It keeps the knee stable and prevents the lower leg from moving uncontrollably. But it’s also susceptible to injury — especially among athletes. And, as Duggan would learn, it takes a lot of work to get back to normal after you hurt your ACL.

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According to the Centers for Disease Control and Prevention, ACL injuries affect as many as 250,000 Americans each year. Women tend to be more at risk than men because of differences in strength, anatomy and genetics. And most of these injuries occur in people ages 15 to 45, who tend to be the most physically active.

Dr. Stephan Prô, a sports medicine physician and orthopedic surgeon at OrthoKansas, said ACL injuries are common in sports such as basketball, volleyball, soccer and football. He said they often occur when a person plants their foot and then twists and turns the rest of their body a different way.

In addition to pivoting and twisting motions, ACL injuries can be caused by stopping movement suddenly, changing movement rapidly or landing after a jump or collision incorrectly.

But even though athletes are at greater risk of ACL injuries, they’re not the only ones who are affected.

“We see ACL injuries within all age groups,” Prô said. And although they’re most common in athletes, he said they could also happen in more mundane mishaps such as slipping on ice or falling off a ladder.

How do you know when you’ve injured your ACL? If you have any of these symptoms, it could be an ACL injury, and you should seek medical treatment promptly to prevent it from getting worse.

• A popping noise and/or discomfort while moving your knee

• Pain and swelling in your knee area

• Inability to move your knee as normal

• Tenderness along the joint line

The American Academy of Orthopedic Surgeons groups ACL injuries into several different levels of severity, from a “grade 1 sprain,” which happens when the ACL is slightly stretched, to a “grade 3 sprain,” when the ligament is completely torn in half. However, that most severe type, grade 3, is also the most common.

Prô said he has seen some patients who seek immediate medical attention after a sudden ACL injury, and others who have a more chronic ACL injury.

“The majority of patients present to the clinic within a few days of an injury, but we also see patients who present weeks to months after their injury,” he said. “The most common symptom that we see in the case of a chronic ACL tear is instability or overall lack of confidence in the knee. In either case, the diagnosis is made by a combination of clinical examination and MRI findings.”

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While it’s possible to treat some ACL injuries without surgical intervention, Prô said that about 95% of patients have surgery to correct the injury.

Nonsurgical treatment consists of aggressive physical therapy and bracing, but it often requires patients to limit their activities. For people who want to be active, especially athletes who want to return to doing sports that involve jumping and twisting, Prô said he would recommend surgery to restore the ligament to its original functionality.

The typical surgery for an ACL injury is called a reconstruction, and it’s done on an outpatient basis, meaning that the patient has surgery and returns home for recovery within the same day. After it’s finished, patients leave the hospital on crutches and use them for approximately two to three weeks until they are comfortable moving without them.

Recovery is different for everyone, and some patients may be on crutches and may undergo physical therapy for longer than others. It takes approximately six to nine months for patients to fully recover after surgery and return to their full athletic ability, and objective measurements of strength, power and range of motion are used to determine when it’s safe for an athlete to return to play.

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Within a week of the surgery, physical therapy begins. Tyrel Reed, a physical therapist with LMH Health Therapy Services, said that in the early stages of physical therapy, the patient will come in two to three times per week to help re-establish their range of motion, normal walking mechanics and basic strengthening.

In the first month of physical therapy, Reed said physical therapists help patients extend their knees and improve their quadriceps muscle functions. After that is complete, they work to gradually restore range of motion in the knee while adding in more functional tasks such as walking, squatting and using stairs.

“In the later stages, typically three months and on, we will decrease the frequency of sessions to one to two times per week, or even every other week,” Reed said. “During this stage, the patient will have a structured strength and conditioning program to help with the restoration of remaining deficits, in addition to their therapy sessions.”

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When Duggan hurt her ACL, she didn’t have to wait long for treatment, because Prô was already there as the team physician.

“Dr. Prô immediately comforted me,” she said. “I knew something bad had happened, and even though I hadn’t had any experience with him, I immediately knew I could trust him. He made the whole process really easy.”

Duggan’s surgery was scheduled within a week of her injury. She had some struggles early on — the first night after surgery, she said she was “so nauseous, unable to sleep and in pain,” and Prô had to adjust her medications. And after she started physical therapy with Reed, she was facing a whole new set of obstacles.

During her rehabilitation, Duggan said she wasn’t the easiest patient. She was having a tough time getting the extension in her leg back, and she was very discouraged by how slowly she seemed to be progressing.

Fortunately, she said, Prô was there to help her get on the right track.

“Dr. Prô would come into the clinic on Monday or Tuesday and check my recovery,” Duggan said. “I was in the training room thinking that I’d never get back to where I was. He sat down with me and said, ‘Look at me. You can do this.’ I needed someone to tell me it was going to be OK, and he did that.”

“I can’t say enough about Dr. Prô and the care he provided,” she said. “He was easy to connect with, and I immediately knew I could trust him. He genuinely cared about me from the beginning and wanted to make sure I was able to do what I love.”

— Autumn Bishop is the marketing manager and content strategist at LMH Health, which is a major sponsor of the Journal-World’s Health section.