How To Save Your Knees

Everybody knows someone who has hurt a knee or torn an ACL. Here’s the new thinking on what to do if you are injured. 

By Dr. Ben Rosenburg

There you are at your favorite ski hill, ripping down a run on a big powder day, when come into a turn a bit late and get tossed into the back seat. You turn quickly to recover and suddenly your knee goes “pop.”  You plow into the next bump and go down. It hurts some, but the unsettling sensation is that your leg went one way while the rest of you went another. You stand up and gingerly try to bear weight. The knee buckles and down you go again.

After a couple of choice expletives, you come to the realization that you are not going to be skiing down. As you sit in the snow waiting for the ski patrol to arrive you can’t help but start to think about what will come next.

This scenario is an all-too common description of a torn anterior cruciate ligament (ACL).  A rope-like ligament that connects the femur to the tibia, the ACL plays an important role in knee stability.

ACL tears are usually accompanied by knee pain, swelling and difficulty bearing weight. These initial symptoms generally improve over several days (or weeks), and it may appear that the knee has recovered.

However, if the ligament does not heal solidly (and unfortunately it often doesn’t), the knee may continue to feel unstable.  Or, it may feel OK for a while, only to give way again when you return to twisting sports. There may also be other injuries to the meniscus (cartilage) or ligaments that may lead to pain, instability and inability to participate in sports.  That’s when the orthopedic surgeon gets a call.

Do You Need Surgery?

A common misconception is that all ACL tears require surgery. Sometimes they do, but not always.  In fact, while many athletes benefit from surgery to stabilize their knee, others may do well with non-surgical treatment.

Several factors determine whether or not a patient will require surgery, including presence of other injuries, age, activity level, desired sports participation, condition of the secondary stabilizers (other ligaments, cartilage and muscles) and, importantly, patients’ personal preference.

As a general rule, athletes who participate in sports which involve jumping, cutting or twisting place higher demands on their knees. They are  more likely to benefit from surgery than those who primarily do straight-ahead activities like jogging, biking or hiking.

I like to use the concept of “exposure risk” when discussing options for treatment. By “exposure risk” I mean the number of opportunities the athlete has to reinjure his or her knee.

A 15-year-old high school soccer player has a much higher exposure risk than a 45-year-old recreational runner and cyclist.  An athlete with a higher exposure risk may be better served by surgical treatment of his or her ACL injury.

A person with a more solid knee or “tight” joints before an injury may still have good stability after an ACL tear. A more loose-jointed person may find the knee to be very unstable after a tear, as they depend on their ACL to hold their knee in place even for lighter, everyday activities.

Your surgeon should review all these factors with you and work with you to decide what’s the best treatment. Physicians call this process “shared decision making.”  Ideally, the athlete should feel that he or she has weighed all the above-mentioned considerations before making the choice about treatment.

Athletes who choose non-surgical treatment still need to diligently rehabilitate their knee to allow maximal recovery and return of function.

If the athlete and surgeon agree that surgery is preferred, there are a few important choices to make, including timing of surgery, repair vs. reconstruction, graft type and return to sport criteria.

When and How to Have Surgery?

One of the most common complications after ACL surgery is knee stiffness.  Surgeons know that if the athlete goes into surgery with a stiff knee, the chances of ending up with a stiff knee after surgery are much higher.

For this reason, ACL surgery is usually delayed until the initial swelling has abated, a limp has been resolved, and range of motion (especially the ability to fully straighten the knee) has returned.  In some cases, surgery may be undertaken sooner,

especially if there is a severe cartilage injury that causes the knee to be “locked.”  Most patients with ACL tears will work with a physical therapist to help guide them through the process of getting the knee ready for surgery and recovering after.

The next question is what type of surgery you should consider. In the 1960s and 70s, when ACL injuries first started to be treated surgically, surgeons attempted to repair the ACL by stitching the torn ends together or reattaching the torn ligament to the bone.

Unfortunately, these early repairs were often unsuccessful, leading surgeons to develop techniques to reconstruct, rather than repair the ACL. Reconstruction involves removing the old, torn ACL fibers and using a tendon graft, attached through drill holes in the knee, to replace the ligament.

ACL reconstruction with a tendon graft is usually successful at allowing athletes to return to a sport, although the procedure can be associated with significant pain, swelling and prolonged rehabilitation.

Recently, a few centers have been re-examining the concept of repairing the torn ACL, using more modern fixation and rehab techniques. The jury is still out on this procedure, however, and the vast majority of sports medicine knee surgeons still recommend ACL reconstruction.

The tendon grafts most commonly used for ACL reconstruction include using the patient’s own hamstring tendons (the cords that run behind the knee) or a portion of the patellar tendon (the tendon that runs from the lower end of the kneecap to the tibia.) Tendon grafts that come from a patient’s own tissue are called “autografts.”

Sometimes, in order to avoid having to remove the patient’s own tissue, surgeons use cadaver tendons, called “allografts.” There are pros and cons to autografts and allografts, and you should have a full discussion of the risks and benefits of each graft type with your surgeon prior to making a decision about which graft to use.

When Can You Be Back at It?

Rehabilitation after ACL surgery is often as important as the surgery itself.  Here in Vermont we are fortunate to have both excellent sports medicine knee surgeons and excellent physical therapists who specialize in treating athletes.

When to safely return to sports after ACL surgery is a hotly debated topic.  I tell my patients to expect a 6- to 12-month recovery period. For those athletes that do a seasonal sport, during the first season back the knee is rarely 100 percent.

Return to play may be affected by the type of graft used, the presence of other injuries, history of previous knee injury and type of sport. Ultimately surgeons and therapists want to protect you from re-injuring the knee and having to go through the process all over again, so we often err on the side of caution.

If you do have a knee injury, ask plenty of questions, and follow the advice of your surgeon and physical therapist.

An avid skier and a sports medicine orthopedic surgeon who’s been practicing in Middlebury for more than two decades, Dr. Ben Rosenberg has treated hundreds of athletes with knee injuries, many with ACL tears.