ACL tears: A painfully common knee injury

It’s the injury that often begins with a dreaded “pop,” followed by knee pain and swelling. Anterior cruciate ligament (ACL) injuries occur about 100,000 times per year in the U.S. — most often to young athletes while playing sports. Soccer, basketball, football and tennis players experience the largest number of ACL injuries.

A sprain or tear of the ACL typically happens when the bones of the upper and lower leg twist in opposite directions under the full weight of the body. This often comes with deceleration of speed and a sudden change in direction with a planted foot, or what is often referred to as a “cutting maneuver.”

An all-too-common knee injury

While an ACL sprain or tear can affect anyone at any age, it most commonly occurs in athletes. About two-thirds of these injuries happen to 15- to 29-year-olds while participating in a sport.

Women have a threefold greater risk of ACL sprains and tears than men. The reasons for their higher injury rate include smaller anatomy, less muscular support for the knee joint and even hormonal function, which can make joints more vulnerable to injury during certain phases of the menstrual cycle.

How to know if you might have an ACL injury

Certain clues signal an ACL injury — the pop, followed by difficulty walking and pain, swelling and tenderness of the knee area. A physician can use a physical exam and an MRI to confirm an ACL injury diagnosis.

The immediate treatment is to immobilize the knee and apply ice. A patient’s long-term treatment options vary depending on several factors, including age, pre-injury activity level and a willingness to take it easy, according to board-certified orthopedic surgeon Elisabeth C. Robinson, MD.

“Our ultimate goal with treatment of an ACL issue is to prevent another knee injury while enabling the patient to return to their desired level of work or athletics,” explains Robinson, who practices at UVA Orthopedics, a department of Novant Health UVA Health System Culpeper Medical Center.

Which treatment is right for you?

The more conservative treatment options for an ACL injury include physical therapy aimed at strengthening the muscles that support the knee joint, as well as knee braces and limiting activities. Another choice is surgery.

So how do you know which treatment approach is right for you? “First, we consider the age and activity level of the patient,” Robinson notes. “People — especially older people — who don’t engage in a lot of rigorous or high-impact physical activity probably don’t need ACL reconstruction surgery. With physical therapy and time, many people are able to walk, bike and even jog following an ACL injury, even without surgery.”

Younger and more physically active patients may be candidates for ACL reconstruction surgery. About 80,000 procedures are performed annually in the U.S., according to the National Institutes of Health. “People in their teens and young adults who are doing more rigorous sports like soccer or basketball, or who have jobs that require physical activity where the knee is buckling, typically do need surgery following an ACL tear,” says Robinson. “Without surgical reconstruction, every time the knee buckles, there’s a risk that the patient is damaging the joint’s cartilage, which can cause rapidly accelerated post-traumatic arthritis of the knee joint.”

The prognosis following an ACL injury

If you or a loved one has suffered an ACL sprain or tear, the prognosis can vary greatly, depending on your age, activity level and which treatment route you choose.

A full recovery is possible for those with a complete tear who decide to forego surgery. “Typically, patients will heal and can learn to compensate for the injured knee,” explains Robinson. “The torn ACL will scar into the surrounding tissues, although it doesn’t return to its original state. The knee joint will still be loose, making it susceptible to reinjury. Physical therapy therefore is needed to strengthen and stabilize the surrounding structures.”

Those who choose surgical reconstruction and postoperative physical therapy often return to their previous level of activity or athletics. While outcomes vary by person, Robinson says patients can usually start running about three months after surgery and resume sports training at around six months post-surgery.

Learn more about ACL injury and prevention at a lecture, “ACL injury: From start to finish,” Thursday, April 26, at 6 p.m., by Elisabeth Robinson, MD, an orthopedic surgeon at UVA Orthopedics, a department of Novant Health UVA Health System Culpeper Medical Center. As a former Division I collegiate soccer player and board-certified orthopedic surgeon, Robinson knows ACL injury well. This lecture is free and open to the public. Registration is suggested, but not required. To learn more about UVA Orthopedics, please visit our website.