The player tries to cut sideways and his leg dips at the knee. It's a slight and incidental move, it always is. Innocuous is the word normally used. The leg's not broken, but it needs fixing.
The player collapses to the ground and grabs at the leg. They wrap their hands across the front of the leg just below the knee and pull backwards as though to hold the leg together.
That is the sign, the tell, that the player has torn their anterior cruciate ligament.
It is not scientifically proven but Julian Feller reckons it is the most consistent sign in sports medicine. It is the player reacting to the sensation that their tibia is falling away from them and they reflexively grab the leg, even briefly, to hold it together.
Not everyone who does an ACL grabs their leg this way, but everyone who grabs their leg this way has normally done an ACL.
No one has reconstructed more AFL footballers' knees in the past two decades than Julian Feller. He knows more about knees and reconstructions in the game than anyone.
Yet he feels like the more he knows, the less he knows.
For all of the advances in medicine, knee injuries are like goalkicking – the injury numbers have not improved.
The injury rate is the same but the return-to-playing rate is better – players now get back to playing again within a year, where previously many didn’t get back at all.
There are risk categories but no firm science on whether some people are predisposed to knee injuries.
“I find it hard to understand if you take Alex Johnson as the example, having come back from multiple reconstructions on one knee, he played NEAFL, he plays a game of AFL footy and the next game he does his other knee,’’ Feller said.
“What it is that makes him more likely than someone else in the team that day to tear the knee?”
The same goes with Matthew Scharenberg at Collingwood.
Before someone does their first knee there is no warning sign to suggest they are more predisposed than anyone else to the injury. It had been assumed people with loose joints would be more at risk but the evidence doesn’t support it – loose joints often means loose ligaments, too.
Opening up someone’s knee after they have done their ACL, there is nothing inside that points to an obvious cause of the rupture.
“There is some evidence about the shape of the knee at the top of the tibia, it has got a slope on it and if that slope is higher, that might be a risk factor. You can see it on X-ray but are you going to go and change it? It’s a massive operation to go and change the slope of a knee,” Feller said.
There is no risk category for doing a first ACL, but once you have done one, you enter a new risk category.
“If you are under 20 when you have your first reconstruction, your risk [of another] goes up. If you are under 18 it really goes up that you will have another injury to the same knee, or the other knee,” Feller said.
“If you are a [young] male you have got a really high risk of further ACL injury.
“Beyond that it’s hard to know. Family history is probably a risk factor but I don’t know what that means. You could just come from a family that plays active sport or is there some genetic predisposition?
“There are a lot of strong opinions around but not a lot of evidence.”
It is doubtful there is much that can be done to prevent it. There are exercises that assist in balance and landing techniques, but typically in the AFL the injury occurs not when landing but when cutting sideways.
There is a school of thought that you can prevent or limit the exposure to knee injury by strengthening the muscles around the knee. There might be truth in this but you while you can strengthen a muscle, you cannot strengthen a ligament.
Typically to reconstruct a knee the surgeon takes a graft of a tendon from elsewhere and replaces the anterior cruciate ligament. Historically, tendon from the patella was used, then from the hamstring and now increasingly from the quadriceps.
Quadriceps tendons allow a bigger graft and when players return to playing they tend not to tear their quadriceps at the rate they do their donor hamstrings. Quadriceps also tend to accelerate the early stages of the rehabilitation phase.
“If you can get the stuff that normally takes four or five months done in eight or 10 weeks then you are able to progress to the next stage earlier, which might mean you can go back and play earlier,” Feller explained.
“It’s impressive how good they look early on. Will it get them back playing earlier? I don’t know.
“Most times you can get a bigger graft from the quads. Lynden Dunn, I said afterwards, ‘You have the biggest graft I have ever taken out of quads’.
“You certainly can get a bigger graft. I think it is a good graft but I wouldn’t go pushing it as better just yet.”
There has also been a swing back to an additional procedure, called a lateral tenodesis, performed to the outside of the knee during a reconstruction. It further tightens and strengthens the knee but there was a thought it restricted lateral movement slightly and so it gradually phased out.
“The lateral tenodesis will tighten as the knee twists a little bit before the ACL tightens so it takes some of the load off the ACL,” Feller explained.
“It’s not going to be for everyone. It’s not going to guarantee you don’t tear your graft again. I did that on Christian Petracca because he was young and had a family history and you go, ‘Well we know he is male, under 20 and a family history’, so he has three risk factors for having a re-injury so we thought, ‘Is there something we can do to try and reduce it?’ So we did that.“
He did the additional lateral tenodesis on Scharenberg given his history.
For a period the quick return to sport offered by LARS, which uses a synthetic tendon, made it appealing but it isn't commonly recognised as a long-term solution.
“The re-injury rate is really high, like about 60 per cent, and that is too high,” Feller said.
How quickly you can get back to playing and how often you re-injure yourself are the two most compelling questions in the field after why someone does their ACL in the first place, or why certain people do them and not others.
In the AFL players are typically sidelined for 10 to 12 months. But that is just a gut feel based on what historically has occurred and worked. There is no testing to confirm when the time is right to resume playing.
In other sports around the world return times are shorter. In English Premier League soccer, players return after six to eight months. In the NFL, it is shorter again.
So why do we wait?
“One of our PhD students has looked at ACL injuries over a 13 or 15-year period and it does seem the re-injury rate is higher in AFL than other sports,” Feller said.
“Where the return-to-sport rate is about the same, the rate of re-injury is higher.
“It is interesting why in some sports in some countries it is assumed you will get back and play at six months whereas in Australia traditionally it has been 12 months.
“Sometimes we have set players up for an early return and, touch wood, when we do that they seem to be safe in terms of re-injury an it makes you think, 'Why can’t we do that in all cases?'
“There has been a rugby league player who has come back and played at seven months and he is going well. It all comes back to when it is safe and we don’t know.”
Feller attended a conference in the US where they asked what the re-injury rate was for his footballers returning to play three months after surgery. It was zero – AFL players don’t return after three months. But NFL players do, often back on the field after three and five months.
“When we compare our AFL stats of re-injury, they are higher than other sports where they are going back to sport earlier. AFL is a really tough sport for ACLs.”
For more information on ACL rehabilitation or ACL Protocols contact Optimus Health Group on 03 9913 8986.