Anterior Cruciate Ligament Reconstruction

The Anterior Cruciate Ligament

The anterior cruciate ligament (ACL) is an important stabilising ligament in the knee. When the ACL is damaged, overstretched or torn, the knee can feel very unstable and will “give way”.

There are many ways an ACL can be torn, but it is frequently due to a sports-related injury. The ACL is particularly important when playing sports where rapid direction changes are frequent, such as netball, soccer, cricket, rugby and football.

Tearing your ACL is painful and causes swelling that can last for several weeks.

Swelling normally settles down, so pain itself isn’t usually an ongoing problem, but “giving out”, especially in sport, can be an issue.

A torn ACL rarely heals spontaneously, but urgent surgery is not always necessary. Some people manage well without an ACL, or occasionally the knee can stabilise by itself. Most times the decision to reconstruct a torn ACL is made down the track if the patient is having ongoing problems with troublesome “giving way”. On other occasions, for example where additional significant damage to the knee has happened at the same time as the ACL injury, early reconstruction may be advisable.

Anterior Cruciate Ligament Reconstruction

An (ACL) anterior cruciate ligament reconstruction is very different from a knee replacement. It involves fashioning a new ACL from some other tissue and passing that through the knee in the same place as the original ACL.

In most cases there isn’t anything artificial about an ACL reconstruction and because the operation involves making a new ACL, rather than fixing the torn one, it can still be done years after the original injury.

Typically, the knee’s ACL reconstruction is done by using hamstring tendons or the patella tendon. Dr Martin has expertise in both methods and also with ACL revision or re-do surgery. The surgery can take up to 2 hours and usually involves 1 night in hospital.

It is important to clearly understand the risks and benefits of a procedure before proceeding with surgery. Every surgical procedure has risks associated with it. Dr Martin will go through the pros and cons of the varying procedures to help you make a good decision.


ACL Reconstruction FAQ 

When can I return to sport?

To return to sport your muscle control and coordination need to be excellent and the graft needs to have achieved full strength. It not recommended to return to contact or cutting sport until 9 to 12 months after the surgery.


Because the graft also needs to be what is called re-vascularised. What that means is that the graft was healthy living tissue on the day of surgery, but then it loses its blood supply when it is placed in its new site. From that point it dies and gradually weakens until new blood vessels grow back into it to allow it to strengthen again.

The time the knee is most at risk of re-injury is around the 5-6 month mark when the operated knee feels good but the re-vascularisation process is incomplete.

A physiotherapist-supervised rehabilitation is very beneficial.

Will I need crutches or a brace afterwards?

That depends mainly on what other surgery was required at the same time. In most cases crutches or a brace are only used according to levels of pain and comfort after ACL surgery.

What can go wrong?

There is about a 5% risk of failure in terms of ongoing “giving out” or re-rupture after ACL surgery. The risk of re-rupture is slightly lower for the patella tendon technique. There is also about a 5% lifelong risk of tearing the other knee’s ACL for someone who has already torn an ACL.

A deep infection in the knee is very uncommon, but can be a big problem. For various reasons it is possible to have ongoing pain or stiffness, or get arthritis after ACL reconstruction. A downside of the patella tendon technique is that it can be a bit sore to kneel and there is a risk of patella fracture or patella tendon rupture.

Numb spots around the knee or even further down the leg are reasonably common. Major injury to the nerves or blood vessels is exceedingly rare.

It is reasonably common to feel a prominent screw on the shin bone after the swelling has gone down. This may be removed if it is problematic.

Every surgical procedure has risks associated with it. These include a risk of blood clots on the legs or lungs, heart attack or stroke.