WHAT IS AN ACL INJURY TO THE KNEE?

The anterior cruciate ligament (ACL) is the most commonly injured knee ligament. The ACL controls how far forward the tibia moves in relation to the femur (see diagram below) and if the tibia moves too far, the ACL can tear. The ACL is also the first ligament that becomes tight when the knee is straight so if the knee is forced past this point, or hyperextended, the ACL can also be torn.

The ACL is often injured during high action sports activities such as motocross when the athlete suffers a direct blow, a twisting motion or hyperextension. For example, the hyperextension and twisting mechanisms can occur when a motocross rider catches his/her foot in a corner. The tearing of the ligament results in a loud pop and the feeling of instability in the knee. Often the medial collateral ligament (MCL) and the ACL are injured at the same time. 

WHY DO I NEED MY ANTERIOR CRUCIATE LIGAMENT?

The ACL stabilises the knee and the instability caused by the torn ligament leads to a feeling of insecurity or “giving way” of your knee, especially when trying to change direction. People with a torn ACL will feel instability when walking down hills or stairs, cutting/pivoting, starting and stopping quickly and when their knee is in full extension. The knee may also feel like it can bend too far backwards.

The symptoms following a tear of the ACL are not always exactly the same in severity for all people. Typically, you will experience swelling of the knee within a short time following the injury. This swelling is due to bleeding into the knee joint from torn blood vessels in the damaged ligament. The pain and swelling from the initial injury will usually go away after a few weeks, but the instability remains. This physical instability and the inability of the patient to control the knee require treatment. Many people have the instability treated by orthopaedic surgery to reconstruct the ligament to increase the stability of the knee and prevent damage to the joint.

FOUR-POINTS-OF-LEVERAGE™

Since 1984, DonJoy’s goal has been to revolutionise orthopaedic bracing. Through the Four-Points-of-Leverage™ rigid cuff and strap configuration, a posterior force  is applied to the tibia preventing anterior movement of the tibia. The Four-Points-of-Leverage™ design is used on the Defiance®, Defiance III®, Female Fource™, Armor, 4Titude® and Legend™ braces.

UNIQUE INTEGRATION SYSTEM

The centre of the hinge is just posterior to the midline and just superior to the joint line. This allows points 1 and 3 to compress soft tissue, isolating the femur and bringing it forward. Points 2 and 4 draw the tibia posterior, generating a net differential force, or constant load, directly over the tibia, preventing it from moving forward. Read more