ACL Injuries: What You Need to Know

September 12, 2014

With football and soccer season underway, more young athletes will be tearing their ACLs despite the best preventive efforts of their coaches and athletic trainers. In this Q&A, William Garrett, MD, a Duke orthopaedic surgeon and nationally recognized ACL expert, explains why the injuries occur so frequently, and what to do if your young athlete experiences an ACL tear.

What is the ACL?

The anterior cruciate ligament (ACL) is one of the primary ligaments that hold together the bones in your knee. One of the most common knee injuries occurs when the ACL tears. ACL injuries range from a mild sprain, to a partial tear, to a complete ACL tear, which may require surgery.

Are ACL injuries preventable?

There is little data to show that these injuries are preventable, and if so, how to prevent them. Strictly run studies suggest that certain types of athletic conditioning can help, but the vast majority of prevention programs do not follow the same rigorous guidelines set up in those studies. If you look at NCAA injury surveillance data, ACL injuries continue to occur at a steady rate despite programs designed to prevent them.

Who is at risk?

Any athlete who plays a sport like football, soccer or basketball that requires a quick stop, turn or pivot. It’s the impulsive move on the field that causes the ligament to tear, and 8 out of 10 of ACL injuries are non-contact. Often it happens when the player has control of the ball, turns to look for an opposing player, and makes a quick step in the wrong direction.

How do I know if I have an ACL tear?

If you hear a pop, your knee hurts and swells, and you can’t continue to play, chances are very high that you’ve torn your ACL. An orthopaedic surgeon will order an MRI to confirm the diagnosis, and determine whether surgery should be recommended. It’s common for physicians unfamiliar with ACL injuries to misdiagnose. If you think you or your child has a torn ACL, see a sports medicine specialist.

Is surgery a must?

Not always. We know that ACL reconstruction will make the knee stronger and allow you to return to sports that require cutting and pivoting without difficulty. However, if you have no intention of engaging in these sports again, you may opt against surgery.

How do I choose an ACL surgeon?

Experience counts. Ask your surgeon how many ACL reconstructions they perform. A minimum of 25 ACL surgeries per year is acceptable.

Next, find out what type of surgery they recommend. ACL repairs don’t work.  Studies show that repaired tendons will fail over time. At Duke, we perform ACL reconstructions on young athletes using their own tendons. We call this an auto graft. In older adults, we are more likely to use tendons from a donor – known as an allograft -- because their success rates are similar to those from autographs with less pain and disability after surgery. Three years ago we published research that indicates the size of the grafted tendon can impact success. The smaller the tendon – which is common in young people - the higher the failure rate. We have a bank of donor grafts that we can use to supplement their own tissue, which increases the likelihood of a successful ACL reconstruction.

How soon can I get back to playing?

Six to nine months of physical rehabilitation will get you back to competitive play.

If my ACL tore once, can it tear again after surgery?

It’s possible. Studies indicate that up to 30% of school-age soccer and basketball players will reinjure the same knee or the other knee. We know it’s important not to return to play too early. It’s also important to get the proper physical rehabilitation. Still, some people may reinjure their knee despite their and our best efforts.

Will I get arthritis in the future?

Time will tell. The ACL surgeries we are doing now weren’t being done 20 years ago. We don’t have the long-term data to know if they will lower the incidence of arthritis that is currently associated with ACL injury, with or without surgery.