ACL injuries (anterior cruciate ligament) are so common that most people already think they have an idea of what to expect when it happens to them. But in reality, there are many ways of approaching this type of injury and taking care of the person is just as important as taking care of the injury. Most surgeons agree that an active, young athlete should have an ACL reconstruction surgery after an injury. In my opinion, anyone with a healthy knee that participates in high risk activities requiring cutting, pivoting, sudden movements, and speed, is a good candidate for an ACL reconstruction surgery.
The most common question I get is “how long will I be out?” That is a complicated question to answer quickly. We think of an ACL tear as a season-ending injury and for the most part, it is. Most sports have seasons that range from 4-6 months, but many people participate in more than one activity and so the question of “how long?” becomes more complicated.
To review the biology, it is important to know that when we reconstruct the ACL, we are essentially building a new one using tissue from the patient. But we also have the option to use allograft, or cadaver/donor graft tissue. As we covered in “Autograft? Allograft? Which is Better for Reconstructing an ACL Knee Injury” article, both have pros and cons but the most important concept is that either one involves placing devitalized (detached) tissue into the knee. That means that this tissue has to heal and this process likely takes a year or more.
So how do we get people back to their sport sooner than biology allows? We push the limits. The most obvious thing that patients notice following surgery is the profound weakness of the knee and the quadriceps that occur almost immediately. In order to restore and retrain the biomechanics of the knee, we start an aggressive physical rehabilitation program as soon as possible. We rely on the strength of the legs, gluteus, and lower extremity balance to protect the ACL until it fully heals. In fact, in places where formal physical therapy is scarce or cost-prohibitive, it does take a year or more to return to full activity.
The most important aspect of managing expectations of an ACL injury is to focus on what the patient wants, what the patient needs, and how to maximize their understanding of the process that will get them there. As good as the surgery is, it is still not the original ACL and there are some compromises that patients need to understand so that they will have a good outcome. I always explain to patients that the goal is to have normal function without pain, not a “normal” knee. I don’t think that is possible. In order to achieve normal function it takes at least 6 months of physical therapy, sometimes more. Although you do hear of “accelerated” knee rehabilitation programs that return athletes at 4 months, this is probably too soon. Waiting longer and protecting the knee with controlled activity is the safest option to avoid reinjuring the knee.
Written by: Michelle Wolcott, MD, Associate Professor, CU Sports Medicine, Children’s Hospital Colorado