Megan Rapinoe was a college sophomore the first time it happened. After a year of surgery and rehab, she did it again. The University of Portland Pilots midfielder injured her anterior cruciate ligament (ACL) twice. After missing most of her sophomore season, she admitted to being in a hurry to get on the field. The re-injury humbled her. She took her time recovering. She waited until she was ready before rejoining her team. Rapinoe’s patience paid off. Today she is a bonafide star, having won the gold medal three times as part of the U.S. Women’s National Soccer team.
Former New England Patriot stars Tom Brady and Rob Gronkowski have torn their ACL. After surgery and rehabilitation, they returned to their sports. So did footballer Zlatan Ibrahimovic and Major League Baseball’s Adam Eaton. ACL ruptures are more common in soccer, football, and basketball because of the running and pivoting involved. Nine out of ten MLB players are back on the field after an ACL injury while in the National Football League 20% of running backs and wide receivers never play in the NFL again. Those who do come back rarely play as well as they did before the injury.
Still, ACL tears aren’t the career-enders they once were. There are more treatment options available for athletes and non-athletes alike. But first of all, what is this crucial ligament that seems so prone to failure?
The weakest link
Like strong cords holding your knee in place, the four primary ligaments help link the surrounding bones. There are bone-connecting ligaments throughout our body. Tears are more common with the ones enduring the most stress. Our knees are subjected to unique demands. They are involved when we bend, twist, run, and do a variety of other activities. Roger Federer is considered one of the best tennis players of all time. During his decades-long career, he remained injury-free. In 2016, he hurt his knee badly enough to require surgery and time off the court. He didn’t do it chasing a backhand. He did it drawing a bath for his children.
The knee joint is formed by the meeting of three bones. The kneecap (patella) is between your thigh bone (femur) and shinbone (tibia.) Collateral ligaments run along the sides of your knees. The cruciate ligaments are inside your knee, forming an X. The posterior cruciate ligament is in the back. The anterior cruciate ligament travels diagonally along the middle of the knee. This tiny band of connecting tissue is meant to keep the shinbone from slipping out in front of the thigh bone. It also allows your knee to rotate. Few people give much thought to their ACL –– until it fails.
ACL ruptures usually happen when we stop too quickly or change direction. Poor landings or even getting tackled can also cause an ACL tear. While the injury is associated with young athletes, it also happens with ordinary people performing everyday activities. Over 100,000 ACL tears happen in the U.S, every year. Women are almost nine times more likely to sustain an ACL tear, possibly because of structural or hormonal differences.
There are three degrees of injury or ligament sprains. Grade 1 happens when the ACL is only slightly stretched. It is still able to do its job, and the knee joint remains stable. In Grade 2 sprains, the ligament is actually loose. Partial tears like this are rare. Unfortunately, Grade 3 sprains are the most common. This is a complete tear –– the ligament is literally torn in half, and the knee joint is unstable. With half of these injuries there is some damage to other ligaments or cartilage as well.
If during an activity you hear a distinctive “popping” sound and/or your knee will no longer support your weight, you may have sprained your ACL. Your knee might grow swollen and you will probably feel a distinctive soreness. The Mayo Clinic recommends the R.I.C.E. self-care model: Rest, Ice, Compression, and Elevation. Getting your weight off your knee and resting is vital. So is putting ice on your knee for 20 minutes every two hours while you are awake. You should also have an elastic or compression bandage wrapped around the injury. Finally, make sure your knee is elevated –– stack up some pillows and stretch your leg across them.
Sometimes this is all your sprain will need to heal. Even if you feel better, take your time returning to sports or even every day activities. If the pain persists, you should see a doctor. A physical and visual examination of the knee might suffice. Sometimes X-rays will be ordered to make sure there are no broken bones while magnetic resonance imaging (MRI) can reveal how serious the sprain is. Ultrasound may also be used. Sometimes, rehabilitation is all that’s needed. However, if you have trouble walking or the knee seems unable to bear your weight, surgery may be necessary. Surgery is also recommended for athletes who wish to return to their sport.
Back to the Future
In the 21st century, grafting and transplanting have become a crucial part of Anterior Cruciate Ligament surgery. In an autograft procedure, a patient’s own hamstring tendons replace their ACL. Tendons are harvested. After being braided together, they are threaded through the heads of the shinbone and thighbone and held in place with screws. With allograft transplants, ACLs are created from cadaver ligaments. Recovery from grafting is typically easier than with a transplant. Transplants have their own unique risks, including rejection. Still, in at least one case with both surgeries, the patient achieved a more favorable outcome with the allograft transplants.
Despite advances in ACL surgery, some are looking to techniques first used in the 1970s. The arthroscopic primary repair technique uses an endoscope that is inserted near the knee joint. This endoscope allows the surgeon to examine and repair the injury. Although it fell out of favor, today it is coming back as an option because it is less invasive and has fewer complications than grafting or transplanting. Studies also suggest that favorable outcomes for this procedure are more likely today due to more advanced medical devices along with improved physical therapy programs.
While there are disagreements over the best surgical techniques, there is consensus about when it needs to happen. After a serious ACL tear, you don’t have much time. The best outcomes happen when surgery takes place less than one month after the injury.
- Anterior cruciate ligament injury: diagnosis, management, and prevention
- Mayo Clinic. ACL injury: diagnosis and treatment
- Arthroscopic Primary Repair of Proximal Anterior Cruciate Ligament Tears
- A Narrative Review of Four Different New Techniques in Primary Anterior Cruciate Ligament Repair: “Back to the Future” or Another Trend?
John Bankston is a published author of over 150 nonfiction books for children and young adults including biographies of Jonas Salk, Gerhard Domak, and Frederick Banting.