ACL Rupture.

It’s enough to strike fear into the heart of most. Definitely if you’re an athlete! But how much do you actually know about what’s involved?

ACL reconstruction is one of the most commonly undertaken arthroscopic surgeries in our community. And if you think Kevin Bacon’s degrees of separation are small, I can guarantee if you haven’t had one repaired, someone you know has.

I’ve been working with ACL recons and rehab for nearly a decade. It is one of the biggest injuries a junior Physio can face, and now as a more experienced clinician, I have had the opportunity to see them happen before my eyes on sports fields, see them repaired in operating theatres, and also have been able to assist people with diagnosis, pre op and post op management.

They are definitely a challenging injury to approach. But I really think that it is more about a perception rather than a reality that so many people fear the injury and the rehab so much.

In fact, one of the more common stories I’m told when I meet someone after the surgery, is that they have very little understanding of what it all means and what has actually happened to them. I often see that once someone has a clearer understanding of what, why and how, the process becomes a whole lot easier to engage in.

I love working with knees because they are so complex and so straightforward all at the same time. Knees tell a clear story most of the time and I will never forget many of my mentors over the years telling me that you should be able to diagnose an ACL rupture before you even see the patient, purely by the story they tell. I believe that whole heartedly, that a good clinician should be able to tell the signs of the mechanism and response from the body with most injuries, especially with an ACL rupture.

Let’s take a look.

ACL In Clinic Physio Mosman Park


ACL = Anterior (Front) Cruciate (Cross like) Ligament

It forms a cross like structure with its companion, the Posterior (Rear) Cruciate Ligament. The PCL.

It runs essentially on an angle from low to high from the front of your Tibial Plateau to the back of your Femur.

The purpose of the ACL in a nutshell is to limit rotational movement as well as the forward movement of your Tibia. It combines with the other major ligaments of your knee to provide stability.

It’s a very robust bit of tissue as most ligaments are, however, in particular instances and activities, it is exposed to directional forces that challenge it.


There are a few different ways, however the most common mechanism involves a rotational force, typically while the knee is bent and inwards pressure is being applied. This inwards pressure might be provided by the force of a side step, or otherwise, a tackler, or other external force being applied from the outside in.

A typical description will be that the person felt the knee give way. It will commonly be associated with the sensation of a pop/snap or crack. Sometimes the sound is audible, but not always.

Due to the fact that the ACL is accompanied by a blood supply which is damaged at the same time, the knee will swell relatively rapidly after injury (haemarthosis) and by a few hours after, will often be tight and stiff. This is a pretty unpleasant sensation for most people.

The mechanism of injury for these is quite characteristic, and hence as I mentioned earlier, it is often easy to predict a ruptured ligament by listening to the story.


Still to this day, diagnosing ACL ruptures is one of my favourite things to do. I feel sorry for my patients sometimes as I try hard to not grin when I find one that has been blown out. It’s a very distinct feeling when the ACL is no longer intact. Once again, usually the tests are to confirm, because the history told by the patient has already indicated that it’s likely to be the case.

Here are a couple of the more common tests we would do, to put load on the ligament and see if it is doing it’s job;





The question of surgery vs no surgery is an interesting argument that continues in the clinical world. I have taken many patients through non surgical management of ACL ruptures with great success. It actually depends on a huge variety of reasons as to why or why not the surgery would be undertaken.

There continues to be clinical research into whether or not people can return to sport and dynamic activity without an ACL, and there are actually some very successful outcomes. However, the majority of cases will be surgically repaired, particularly if the person wants to return to a forceful or dynamic activity or environment.

It is a very personal choice though, and I always recommend looking at your options if you are not 100% happy with going straight into surgery. The repair can be done later in time, it doesn’t have to be done immediately.

Here’s an example of a cool video of what the surgery entails. I chose an animation video here to avoid making people squeamish! It takes a few minutes but may highlight a bit about the process for you.


Hopefully this gives you a brief understanding of what it’s all about. There really is a lot to it and you should always get some professional advice about your diagnosis, treatment and rehabilitation.

If you would like any more info on ACL injuries, get in touch

In Clinic

Mosman Park