ACL Reconstruction Surgery in Perth
ACL reconstruction in Perth with Dr Rhys Clark. How the graft works, why preparation before surgery matters more than most people expect, and an honest rehabilitation timeline — including why returning to sport before nine months is the single biggest re-injury risk.
An ACL reconstruction does what its name says: the ruptured ligament is replaced, not stitched back together. A torn ACL does not reliably heal, so a tendon graft is used to rebuild it along the same path.
It is a reliable operation. It is also one where the result depends more on what you do in the months either side than on the ninety minutes in theatre — which is unusual, and worth understanding before you commit.
Before you decide
Worth saying plainly: not every ACL rupture needs reconstructing. ACL rupture covers that decision in full — it turns on what you need the knee to do and whether it actually gives way once the muscles have been rebuilt.
This page assumes that decision has been made.
Preparation is not a formality
This is the part patients underestimate most, and the part they have the most control over.
Three things matter before the operation:
Full extension. Being able to straighten the knee completely before surgery is strongly associated with a better result afterwards. A knee reconstructed while stiff tends to stay stiff.
Settled swelling. Operating on a hot, swollen joint produces worse outcomes and a higher risk of stiffness afterwards.
Quadriceps strength. The strength you take into the operation is a reasonable predictor of the strength you come out with. Muscle lost before surgery has to be rebuilt afterwards, on top of everything else.
This is why reconstruction is rarely done immediately. Several weeks of physiotherapy first — sometimes called prehabilitation — is not a delay to the treatment, it is part of it.
The graft
A tendon is taken and used to rebuild the ligament. Dr Clark typically takes the graft from the kneecap tendon or the quadriceps tendon of the same knee, and occasionally from the other knee. Hamstring tendon is also widely used in Australia.
Each option carries trade-offs — in graft strength, in symptoms at the site the tendon was taken from, and in how rehabilitation is structured. A kneecap tendon graft, for instance, is robust and well suited to high-demand pivoting sport, and is more associated with discomfort kneeling afterwards. The choice is made against your sport, your age, your anatomy and whether this is a first reconstruction or a revision.
It is a fair thing to ask about and a fair thing to have explained.
The operation
Performed arthroscopically. Tunnels are drilled in the thigh bone and shin bone along the path of the original ligament, the graft is passed through and fixed at both ends, and any associated damage — commonly a meniscal tear — is dealt with in the same sitting.
You will have a scar where the graft was taken plus two small scars from the instruments, and some numbness over a small area of the knee is common. Most patients go home the morning after surgery.
Rehabilitation, and the nine-month threshold
Here is where honesty matters most, because this timeline is routinely undersold.
| Stage | Typical timing |
|---|---|
| Home from hospital | Morning after surgery |
| Desk-based work | About 2 weeks |
| Physically demanding work | 2–3 months |
| Light straight-line training | 4–6 months |
| Return to pivoting and contact sport | 9–12 months |
The gap between “light training at four months” and “back playing at nine to twelve” is where people come unstuck, because by six months the knee usually feels fine.
It is not fine. The graft goes through a biological remodelling process after it is implanted — it is weakest somewhere in the middle of that period, at exactly the point most people feel ready.
The evidence on this is unusually clear. Research on young athletes found that those returning to sport before nine months had a rate of new knee injury around seven times higher than those who waited. Notably, achieving symmetrical muscle strength did not remove that risk — which suggests time itself is doing something that training cannot substitute for.
The re-injury numbers
These deserve stating rather than leaving vague, because they are the reason the timeline is what it is.
Among athletes under 25 returning to sport, reported second ACL injury rates are around 23%. In adolescents roughly 15 to 20 years old, figures as high as 30% requiring a further reconstruction within two years of returning have been reported.
The risk applies to the reconstructed knee and to the other one.
That is not an argument against having the operation. It is an argument for finishing the rehabilitation — completing the return-to-sport testing, meeting the strength and hop-test criteria, and accepting that the last three months of a nine-month programme are the ones that protect you, precisely because they are the ones that feel unnecessary.
Being realistic about the result
Most people return to the activities that matter to them, and reconstruction is dependable for restoring stability.
It is also honest to say that a reconstructed knee is not an uninjured knee. A proportion of people do not return to their previous level of sport — some for physical reasons, a good number for reasons of confidence. Kneeling can remain uncomfortable where the graft was taken from the front of the knee. And the risk of developing arthritis in that knee decades later is higher than in an uninjured one, particularly where the meniscus was damaged at the same time.
None of that is a reason to avoid the operation when it is indicated. It is a reason to go in with an accurate picture, and to take the meniscus seriously if it can be repaired.
ACL rupture covers the injury itself and whether reconstruction is needed at all. Knee arthroscopy explains the keyhole technique used to perform it.
To discuss an ACL injury, book a consultation, phone the rooms on (08) 6332 6365 or email info@rhysclark.com.au. Dr Clark consults at Murdoch and Mandurah.
How long is recovery after ACL surgery?+
Longer than most people expect, and the end point is not six months. Most patients go home the morning after surgery and return to desk-based work within about two weeks, or two to three months for physically demanding work. Light straight-line training is generally possible from four to six months. Return to pivoting and contact sport is typically nine to twelve months, and that timing is guided by strength and functional testing rather than the date alone.
Why can't I return to sport before nine months after ACL reconstruction?+
Because the graft is still maturing, and the evidence on this is unusually clear. Research on young athletes found that those returning to sport before nine months had a rate of new knee injury around seven times higher than those who waited. Notably, achieving symmetrical muscle strength did not remove that risk — time itself appears to matter, because the graft undergoes a biological remodelling process that cannot be accelerated by training. Feeling ready at six months is common and is not the same as being ready.
What is the risk of tearing my ACL again?+
Higher than most people are told, and highest in the young. Studies of athletes under 25 returning to sport report second ACL injury rates of around 23%, and in adolescents aged roughly 15 to 20 the figure has been reported as high as 30% requiring a further reconstruction within two years of returning. The risk applies to both the reconstructed knee and the other one. This is the strongest argument for completing rehabilitation properly rather than returning as soon as the knee feels good.
Where does the ACL graft come from?+
The ligament is replaced rather than repaired, using a tendon graft. Dr Clark typically takes the graft from the kneecap tendon or the quadriceps tendon of the same knee, and occasionally from the other knee. Hamstring tendon is also widely used in Australia. Each has trade-offs in strength, donor-site symptoms and rehabilitation, and the choice is discussed against your sport, your age and your particular knee.
How should I prepare for ACL surgery?+
Preparation matters more than most people expect, and it is the part patients have most control over. Being able to fully straighten the knee before surgery is strongly associated with a better result afterwards, as is settling the swelling and rebuilding quadriceps strength. The strength you take into the operation is a good predictor of the strength you come out with. Physiotherapy beforehand — sometimes called prehabilitation — is not an optional extra.
Will I have scars after ACL reconstruction?+
Yes — a scar at the site where the graft is taken, plus two small scars from the arthroscopic instruments. Some numbness over a small area of the knee is common, particularly with a kneecap tendon graft, and usually shrinks over time without disappearing entirely. Kneeling can remain uncomfortable long term where the graft was taken from the front of the knee.
Will my knee be the same as before after ACL reconstruction?+
Most people return to the activities that matter to them, and reconstruction is a reliable operation for restoring stability. It is honest to say that a reconstructed knee is not identical to an uninjured one — a proportion of people do not return to their previous level of sport, some of that for reasons of confidence rather than physical capacity, and the risk of arthritis in that knee decades later is higher than in an uninjured knee, particularly where the meniscus was also damaged.