What is the Anterior Cruciate Ligament (ACL)?

The anterior cruciate ligament, or ACL, is one of the knee ligaments that connects the upper leg bone with the lower leg bone. The ACL mostly prevents forward translation of the shinbone but also helps with rotational stability and hyperextension. It is the most frequently injured ligament in the knee.

How can I injure my ACL?

Approximately 60-80% of ACL injuries happen as non-contact events, without a direct blow to the knee. Your ACL can be injured if your knee joint is bent backward, twisted, bent side to side, with a sudden change of direction or landing from a jump. The chance of injury is higher if more than one of these movements occurs at the same time. Contact (being hit by another person or object) also can cause an ACL injury. An ACL injury often occurs during sports when the foot is planted and a sudden force hits your knee while your leg is straight or slightly bent. This can happen with contact, when you are changing direction rapidly, slowing down when running, or landing from a jump.

How badly can I injure my ACL?

Injuries to the ACL can range from a minor stretches, to a small tear, to a full tear. Without proper bracing or surgery, the injured knee will always be less stable, prone to buckling and further wear of tear of the knee can take place. This wear and tear will predispose patients to early osteoarthritis.

What activities are more likely to cause an ACL injury?

An ACL injury is common in soccer, skiing, football, and other sports with lots of stop-and-go movements, jumping and twisting. Sports where cleats are worn in combination with pivoting movements increase your risk. Falling off a ladder or missing a step on a staircase are other likely causes of injury.

What are the symptoms of an ACL injury?

• Feeling or hearing a pop in the knee at the time of injury
• Pain on the outside and back of the knee
• Swelling within the first few hours after the injury
• Movement limitations because of pain and swelling
• Instability with potential buckling

How do I know for certain if I have an ACL injury?

Along with your description of how the injury took place and your present symptoms, there are clinical tests a physiotherapist, a physician or an orthopedic surgeon can perform to show if there is an ACL injury. However, an MRI is the most accurate way to definitively see an ACL injury. An X-ray only shows images of bone and will not show any ligament structures.

What should I do if I suspect I injured my ACL but I am not sure?

• Rest your knee: Do not go back to activities involving impact or twisting as this can further damage your knee
• Ice your knee: Ice for 20 minutes every 1-2 hours until the swelling goes back to almost normal
• Compress your knee: Use an elastic bandage to give gentle compression, this can be done while icing and throughout the day
• Elevate your knee: Make sure to lie down so your knee is elevated above your heart, this can be done throughout the day based on your comfort
• You may need to use crutches for a few days if it hurts to walk, don’t walk through pain
• You should see your doctor who may request an MRI and a physiotherapist as soon as possible, your physiotherapist can recommend the right exercises and educate you on which activities you should and shouldn’t participate in
• It is crucial to not return back to impact and twisting activities if there is any suspected injury to your ACL, it only takes one re-buckle, which can create a life of knee damage, better be safe and cautious 

There is a confirmed ACL tear based on an MRI will I need Surgery?

Whether you will need surgery or not will depend on how severe the tear is, whether other parts of the knee are injured, how active you are, your age, your overall health, your future goals and how long ago the injury occurred. With a torn ACL you will never have the same amount of stability as you once did. The only way to get close to perfect stability is proper knee bracing and / or surgery.

Should I wear a brace once I know there is damage to my ACL?

With a torn ACL you will never have the same amount of stability, by wearing a custom knee brace, properly fit to your knee measurements, you will increase the stability in your knee. With a torn ACL and no bracing, your will be more prone to buckling and you will further wear of tear the cartilage in your knee. This wear and tear will predispose patients to early osteoarthritis. The faster you get fitted for a custom knee brace after a confirmed ACL injury the better your knee will recover long term. All things similar, wearing a brace will always ensure a better recovery, more support and stability versus not wearing one.

How can I prevent or minimize the chance of injuring my ACL?

The best way to prevent an ACL injury is to strengthen the leg muscles, improve your overall balance and flexibility and increase your functional, sport specific exercises. There are many professionals that are trained to progress patients with these exercises such as physiotherapists, personal trainers, athletic therapists and strength and conditioning specialists to mention a few. Of course avoiding high risk sports with lots of twisting, pivoting and contact will decrease your injury risk as well.

Once I have had surgery to fix my ACL will I need to wear a custom ACL brace?

A person who has torn their ACL has a 15 X greater risk of a second ACL injury during the initial 12 months after ACL reconstruction. This is why bracing for 1-2 years after an ACL reconstruction, especially during sport participation will decrease your risk. Of course proper therapy and exercise helps decrease this risk as well, but once again, all things similar, wearing a brace will always ensure a better recovery, more support and stability versus not wearing one.