ACL injury

How is the ACL injured?

The ACL can tear when the knee twists suddenly while your foot is planted on the ground or when the knee is hit hard (e.g. getting tackled).

People who play sports that involve sudden stopping or changes in direction like netball, rugby, league, soccer, touch rugby, basketball, hockey, and skiing are at higher risk of ACL injury. In Aotearoa New Zealand (NZ), over 3000 people tear their ACL each year.

What happens when you hurt your ACL?

When you tear your ACL, you might feel a pop or giving way, and you may fall to the ground. Your knee may feel painful, swollen, and unstable (such as giving way when walking).

You can also injure other parts of your knee at the same time (such as your bone, cartilage or meniscus, or other ligaments). This is often checked with an MRI scan.

Can an ACL injury heal?

Some people function well (including in elite sport) with a torn ACL, whereas others may do better if their ACL is restored.

In the past, it was thought that ACL injuries could not heal. Recently, it was found that about 1 in 3 people have some healing of their ACL after rehab without surgery.

Limiting knee movement by wearing a brace in the first few weeks after injury may increase healing, but we don’t know enough to be sure. It is also possible that this healing can lead to better function and better quality of life, but this has not yet been proven.