Article by John Miller
What is an ACL Injury?
Your ACL or anterior cruciate ligament is one of four knee ligaments that are critical to the stability of your knee joint. Your ACL is made of tough fibrous material and functions to control excessive knee motion by limiting joint mobility.
One of the most common problems involving the knee joint is an anterior cruciate ligament injury or ACL tear. Of the four major knee ligaments of the knee, an ACL injury or rupture is the most debilitating knee ligament injury.
What Causes an ACL Injury?
An ACL injury is usually a sports-related knee injury. About 80% of sports-related ACL tears are "non-contact" injuries. This means that the injury occurs without the contact of another player, such as a tackle in football.
Most often ACL tears occur when pivoting or landing from a jump. Your knee gives out from under you once you tear your ACL.
Female athletes are known to have a higher risk of an ACL tear while participating in competitive sports. Unfortunately, understanding why women are more prone to ACL injury is unclear. There are some suggestions it is biomechanical, strength and hormonally related. In truth, it is probably a factor of all three.
What Sports have a High Incidence of ACL Injuries?
Many sports require a functioning ACL to perform common manoeuvres such as cutting, pivoting, and sudden turns.
These high demand sports include football, rugby, netball, touch, basketball, tennis, volleyball, hockey, dance, gymnastics and much more. You may be able to function in your normal daily activities without a normal ACL, but these high-demand sports may prove difficult.
Therefore, athletes are often faced with the decision to undergo surgery in order to return to their previous level of competition. ACL injuries have been known to curtail many promising sporting careers.
What are the Symptoms of an ACL Injury?
The diagnosis of an ACL tear is made by several methods. Patients who have an ACL tear commonly sustain a sports-related knee injury.
They may have felt or heard a "pop" in their knee, and the knee usually gives out from under them. ACL tears cause significant knee swelling and pain.
How is an ACL Injury Diagnosed?
On clinical knee examination, your physiotherapist or sports doctor will look for signs of ACL ligament instability. These special ACL tests place stress on the anterior cruciate ligament and can detect an ACL tear or rupture.
An MRI may also be used to determine if you have an ACL tear. It will also look for signs of any associated injuries in the knee, such as bone bruising or meniscus damage, that regularly occur in combination with an ACL tear.
X-rays are of little clinical value in diagnosing an ACL tear.
How is an ACL Injury Treated?
Many patients with an ACL tear start to feel better within a few days or weeks of an ACL injury. These individuals may feel as though their knee is normal again because their swelling has started to settle. However, this is when your problems with knee instability and giving way may start or worsen.
ACL tears do not necessarily require ACL reconstruction surgery. There are several important factors to consider before deciding to undergo ACL reconstruction surgery.
If you don't participate in a multi-directional sport that requires a patent ACL, and you don't have an unstable knee, then you may not need ACL surgery.
Physiotherapy & ACL Exercises
Your best way to avoid ACL reconstructive surgery is to undertake a comprehensive ACL-Deficient Knee Rehabilitation Program that involves leg strengthening, proprioception and high-level balance retraining, plus sport-specific agility and functional enhancement. Your sports physiotherapist is an expert in the prescription of ACL tear exercises.
PhysioWorks has developed a specific ACL Deficient Knee Rehabilitation Program to address ACL injuries for the patient who wishes to avoid or delay ACL reconstructive surgery.
Your physiotherapy treatment will aim to:
We strongly suggest that you discuss your knee injury after a thorough examination from a knee injury clinician such as a sports physiotherapist, sports physician or knee surgeon.
The usual surgery for an ACL tear is called an ACL reconstruction. A repair of the anterior cruciate ligament is rarely a possibility, and thus the ACL is reconstructed using another tendon or ligament to substitute for the torn ligament. There are several options for how to perform ACL surgery.
The most significant choice is the type of graft used to reconstruct the torn ACL. There are also variations in the procedure, such as the new 'double-bundle' ACL reconstruction.
You may have heard of a Lars Procedure, which is a new ACL reconstruction procedure. In some, but certainly not most cases, ACL ruptures a stub of the old ligament can be used as a part of the repair procedure, which can hasten your recovery time. Your surgeon will know whether a lars procedure is an option for you or not. There are higher re-rupture risks involved.
Risks of ACL surgery include:
The good news is that better than 90% of patients have no complications with ACL surgery.
Post-Surgical ACL Rehabilitation
Post-operative ACL rehabilitation is one of the most important, yet too often neglected, aspects of ACL reconstruction surgery. The most successful and quickest outcomes result from the guidance and supervision of an experienced Sports Physiotherapist.
Your rehabilitation following ACL surgery focuses on restoring full knee motion, strength, power and endurance. You'll also require balance, proprioception and agility retraining that is individualised towards your specific sporting or functional needs.
Your sports physiotherapist is an expert in this field. We suggest that you contact them for the best advice in your circumstances.
ACL Injuries in Children
ACL reconstruction surgery is the standard treatment for young, active people who sustain an ACL tear. But what happens when you’re young and your bones are still growing?
Should ACL surgery be delayed until the child is older, or should ACL reconstruction be performed before skeletal maturity?
The concern of performing ACL surgery in children is that there is a risk of causing a growth disturbance in growing children. Growth plate problems as a result of ACL surgery could potentially lead to early growth plate closure or alignment deformities.
However, recent research is showing that the risk of growth plate problems is much less than the risk of permanent knee damage if the ACL is not fixed.
Your knee surgeon is the best person to discuss whether ACL reconstruction is advisable or not.
How to Prevent an ACL Injury?
Preventing an ACL tear has been the focus of recent research, especially the prevention of ACL tears in female athletes. Numerous theories have been proposed to explain why people may tear their ACL, and how they can be prevented.
Current investigations have focused on neuromuscular training to prevent ACL tears. Just as we know that ACL reconstruction patients who have extensive post-operative physiotherapy to rebuild their strength, proprioception and agility we do know that similar ACL exercises can help prevent an ACL tear in the first place. For more advice, please consult with your sports physiotherapist.
Return to Sports with an ACL Injury
Athletes often have particular difficulty returning to their sport once they have sustained an ACL injury, even if they are surgically reconstructed.
Researchers have found that your best chance of returning to your sports post-ACL tear is to have undertaken both:
For more information, please ask the advice of your knee surgeon or sports physiotherapist.
Common ACL Injury Treatments
FAQs about ACL Injury
Knee Brace for an ACL Injury
Many patients will try an ACL brace. The knee brace required will need to stabilise your knee multi-directionally. While trialling an ACL brace is understandable, the success lies in the extent of your ACL instability.
In other words, highly unstable ACL tears will give out eventually regardless of the brace unless it is custom made and moulded specifically to your knee. These ACL braces are very expensive. However, mild instabilities may allow you to work and undertake non-directional change sport if your wear an ACL brace.
Knee Ligament Injuries
Children's Knee Conditions
Other Knee-Related Conditions
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