Can An ACL Tear Heal Without Surgery?

Inside your knee joint are four key ligaments that provide stability and prevent excessive forward, backward, sideways, and rotational motion. Along with your quadriceps (the “quads”) and your hamstrings, they are what make your knee work! The four ligaments are the anterior cruciate ligament (ACL), the posterior cruciate ligament (PCL), the lateral collateral ligament (LCL), and your medial collateral ligament (MCL). They allow your knee to move normally and are the reason your knee remains stable when hiking, running, jumping, and going downs stairs. They are important for the knee’s ability to flex, twist and pivot. This is important for activities of daily living as well as physical work, dancing and all sporting activities. The ACL is the most injured ligament and, when damaged, can cause ongoing instability. If you suspect that you have suffered ligament damage in your knee you should be examined by a skilled physician to make the diagnosis and learn about the best treatment options.

The question most people ask is:

• Can an ACL tear heal with targeted conservative treatment, or does it always require surgery?

We answer that question in today’s blog on ACL tear treatment.

Effective ACL Tear Treatment

ACL injuries are typically classified into three grades, and the grade of your injury typically dictates which treatment is right for you. Let’s take a closer look at the grades:

• Grade 1 - A Grade 1 ACL injury occurs when the ligament is very slightly stretched. The knee feels stable and yet the ACL may look swollen on an MRI. Some micro-tearing may exist, and the majority ligament itself remains intact and very strong. The knee tends to remain relatively stable without surgery.
• Grade 2 - A Grade 2 ACL injury involves partial tearing of the ligament. It’s quite rare to partially tear the ligament, as it often goes right from being overstretched to completely torn. Sometimes grade 2 represents a partial tear of one of the two ACL bundles and the other is intact. There is some increased movement of the knee indicating some ACL function loss. Special exam testing can help sort this out. Again, the knee tends to remain relatively stable without surgery.
• Grade 3 - A Grade 3 ACL injury involves a complete rupture of the ligament. On examination there is more motion than normal (a positive Lachman test) and there may be a positive pivot shift (abnormal shifting of the knee as it is bent and then straightened).

Treatment is a blend of conservative care and surgical reconstruction of the ligament based on the risks of future instability and later risk of cartilage damage. The standard for treatment for patients with a Grade 1 ACL injury is rest, anti-inflammatory medications, and bracing. Physical therapy exercises can help strengthen the knee to aid the overstretched ligament in working more normally. You will also want to gradually increase the amount of stress you put on the ligament while you’re working your way back to normal physical activities, as putting too much stress on the ligament before healing has run its course can leave you susceptible to a complete rupture.

Grade 2 and Grade 3 ACL tears are often treated with a surgical procedure. This is most dependent on the physical demands of the patient. If the individual is an athlete or wants to be able to return to normal physical activity or athletics, surgery may be required to make the knee stable.

The ligament doesn’t get a great blood supply and is unable to close the tear on its own, so the best way to restore stability is with a ligament reconstruction using a tendon graft. The surgery is arthroscopic, has a very high rate of success, and most young athletes can return to practicing elements of their sport within 6-12 months, with many being back to full competition by 10-12 months.

Even though the three grades are helpful in guiding diagnosis and treatment, they often do not provide the full picture. There are other factors that may help decide the best treatment for you:

• First is a locked knee. Sometimes the ACL fragment gets stuck in the front of the knee, or a meniscus tear flips over and gets trapped. This is called a locked knee. Locked knees in general don’t fully resolve themselves without a little help from your orthopaedic surgeon. A locked knee may be the main indication for a repair in many patients.
• Natural laxity is another consideration. It is important for you to have each side checked on physical examination. Some people are naturally laxed or have disorders that include very stretchy collagen (Like Ehler’s Danlos). These patients can have a positive Lachman test and a pivot shift on both sides, and it could be normal for them. Other patients have very tight knees, and even a small amount of instability feels worse to them. The way we can assess that is by looking at the side-to-side difference in the way the knee moves. In practice, this can be checked with a special painless testing device called the KT1000. It measures millimeter displacement in each knee and makes the side-to-side comparisons in a very exacting way.

In short, we can compare the injury to your normal side to see how it compares. Naturally, the bigger the difference the more likely a repair will improve your function. So, deciding on surgery is a mixture of the side-to-side comparison, what is normal for you, whether the knee is locked, and the overall demands you place on the knee. A loose knee in a professional poker player is a far different problem than the same knee in a completive athlete. 

So, to answer our initial question, yes, it’s possible that an ACL injury can be treated without surgical correction. However, if a complete rupture occurs and the knee is locked or relatively unstable and you are an active individual, surgery may be the best path forward. For ACL tears, you’re almost always going to need (and want) to have the injury corrected arthroscopically, using a fiber optic knee scope, and minimally invasive operative techniques.

For more information about ACL tears, other ligament tears, the KT 1000 exam,  or injuries to all the other parts in the knee, pick up a copy of Dr. Reznik’s latest publication, The Knee & Shoulder Handbook, available now on Amazon or at Barnes & Noble.​