Inside the joint there are 2 “C-shaped” discs of cartilage attached to the tibia known as the medial and lateral meniscus. The meniscus gives extra cushioning to the cartilage inside the joint to prevent wear and tear.

The Anterior Cruciate Ligament (ACL) is one of the most important and commonly injured ligaments within the knee. The Anterior Cruciate Ligament’s (ACL) purpose is to provide rotational stability to the knee by resisting the motions of anterior tibial translation (tibia moving forward on femur) and internal tibial rotation (tibia twisting inwards).
A torn ACL results in tibial subluxation (partial dislocation) or instability of the tibiofemoral joint, which results in the “pivot-shift” phenomenon.

If left untreated, a torn ACL, may lead to the onset of early osteoarthritis of the knee due to associated instability and cartilage damage. The instability associated with an ACL injury can cause problems with even the most basic of daily activities such as washing, dressing, stairs and walking.

ACL injuries may not occur in isolation. The meniscus is injured 54% of the time and the medial collateral ligament is also commonly injured. ACL injuries most commonly occur during sports that involve sudden stops or changes in direction, jumping and landing – such as soccer, rugby, hockey, basketball and netball. At the time of injury many people will hear or feel a “pop” in their knee. The knee may swell rapidly and usually you won’t be able to continue with the activity.