How To Diagnose and Repair a Torn Knee Ligament

There may be no more famous acronym in sports than the dreaded ACL— maybe because it’s so often followed by the word ‘injury’.

However, the ACL is not the only part of the knee that can be injured. In fact, it’s just one of four critical ligaments that support the knee and allow us to kick, flex, bend, squat and run. (Quite the joint, isn’t it?)

The knee ligaments — Medial Collateral Ligament (MCL); Lateral Collateral Ligament (LCL); Anterior Cruciate Ligament (ACL); and Posterior Cruciate Ligament (PCL)— are in fact very strong and flexible.

But subjected to certain kinds of stress or trauma, these knee ligaments can rupture or tear.

The ACL is famous because it is the most commonly torn knee ligament. In addition, most patients with ACL damage also sustain some injury to their meniscus or another ligament.

Athletes who’ve torn a ligament often report that they heard a popping noise. There may be knee swelling and there is often pain. Another indication of a damaged ligament is instability. The patient may be unable to stand or walk normally. A ligament injury can be just a sprain. But even if symptoms are mild, it’s a good idea to have the knee examined by our orthopedic staff.

Diagnosing a Torn Knee Ligament

To determine the nature and extent of an injury, we first ask the patient the age-old question: What happened? His or her explanation (usually accompanied by demonstrations of athletic movements and animated gestures) tells us a lot.

Skiers are prone to torn knee ligaments, but so too are soccer, basketball, and football players— anything that involves vigorous action. In skiing, before the invention of the high, supportive ski boot, most injuries consisted of broken bones in the lower leg. Now the danger zone has been pushed up to the knee.

Some surveys show that a non-athlete’s chance of tearing an ACL is one in 1000. It’s much higher for professional athletes. In 2019 alone, the list of pro football players who were out with an ACL injury went to double digits. Each year, it seems, ESPN reports that the Miami Hurricanes’ quarterback is out indefinitely for knee surgery. Millions of other injuries are not so well-publicized.

In our orthopedic clinic, we check the patient’s movement and examine the knee for swelling and tenderness. Arthroscopy is a useful diagnostic tool.

We may order an ultrasound or MRI scan. An x-ray can also be helpful for some cases.

If there is a good deal of swelling, we may drain some fluid to ease the discomfort. While the old advice was to take a nonsteroidal anti-inflammatory drug (NSAID) for pain and swelling, it’s now believed that inflammation is part of the healing process. There are topical painkillers (rub-on gels, for instance) that may be more appropriate.

What You Can Expect With Surgical Repair

Most cases of severe ligament tears are treated surgically, especially if the patient is an athlete or a very active individual.

Surgery is preferred in cases where there is more than one torn knee ligament or for a knee that has sustained repeated injuries.

We often wait for a few weeks before operating, to give the swelling a chance to subside.

In the meantime, we can prescribe exercises to maintain muscle tone and flexibility while the patient awaits treatment.

In many cases, an ACL can’t be repaired and new tissue is required during knee ligament reconstruction. In this situation, we may use a tendon from elsewhere in the body to construct a new ligament. Common donor sites include the patellar (below the kneecap), quadriceps, or hamstring. Some knee ligament surgical procedures can be performed arthroscopically; others require open surgery.

The rehab process for a torn knee ligament can’t be rushed. Any athlete who is in too much of a hurry to return to the playing field risks re-injury and chronic knee problems.

Of course, it’s better to avoid injuries in the first place. Make sure you allow a warm-up period before skating or running hard, to increase blood flow to the muscles and relax the joint. Build strength in your leg muscles, especially the hamstrings and quadriceps which support the knee joint. Some people wear a brace, either as protection after a torn knee ligament or a preventative device. While the usefulness of a knee brace is controversial, there’s no doubt that it’s a good reminder.