Types of ACL Surgery and ACL Reconstruction Rehab

A torn anterior cruciate ligament can be treated with two main types of ACL surgery. The more common option is ACL reconstruction, where the damaged ligament is replaced with a tendon graft. In some cases, the surgeon can keep the original ligament and stitch it back to the bone instead. This is called ACL repair, and it depends on where the tear has occurred.

The orthopaedic surgeon makes that decision, including which graft to use if reconstruction is needed. Our physios at Eastside Physio + Co in Surrey Hills work with patients before and after their operation. Here's what the surgery choices mean and how rehab progresses towards a return to sport.

Types of ACL Surgery: Reconstruction and Repair

Most people who have surgery for a torn ACL undergo reconstruction. Repair is less common because it only works for certain tears. The ACL runs between the thigh and shin bones and helps keep the knee stable. Our page on how ACL injuries happen explains more about the ligament and when surgery might be considered.

ACL Reconstruction

ACL reconstruction is usually done through small cuts around the knee, using a camera and surgical instruments. This is known as arthroscopy, or keyhole surgery. The surgeon removes the torn ligament and puts a tendon graft in its place (Healthdirect). Reconstruction is the most common operation for a torn ACL (Dr Vishal Pai’s ACL guide). There are several graft options, which the surgeon will discuss before the operation.

ACL Repair

ACL repair is an option when the ligament has torn away from its attachment to the thigh bone. The surgeon stitches it back into place, keeping the person's original ligament rather than replacing it with a graft.

Not every tear can be repaired. Dr Pai's ACL guide says surgeons tend to consider it for younger patients, usually within four weeks of the injury. The surgeon decides whether repair or ACL reconstruction is appropriate.

ACL Graft Types Compared

The first choice is between the person’s own tendon, called an autograft, and tissue from outside the body: donor tissue (an allograft) or a synthetic graft. Hamstring tendon grafts are the most common choice in Australia (Dr Pai’s guide). Surgeon guides describe each graft from the operating table, so each one below also notes what it commonly means for rehab.

Hamstring tendon autograft

Where it comes from: Hamstring tendons at the back of the thigh
Commonly reported trade-off: Widely used in Australia, with a smaller incision to collect the graft.
What it means for rehab: Hamstring strengthening is introduced carefully while the tendon harvest site recovers.

Patellar tendon autograft (bone-patellar tendon-bone)

Where it comes from: The patellar tendon below the kneecap, with a bone block at each end
Commonly reported trade-off: More front-of-knee pain and kneeling discomfort reported than with hamstring grafts (Cochrane review)
What it means for rehab: Rehab manages anterior knee pain and gradually builds kneeling tolerance

Quadriceps tendon autograft

Where it comes from: The quadriceps tendon above the knee cap
Commonly reported trade-off: Being used more often by surgeons
What it means for rehab: Early focus on quadriceps activation and strength

Allograft

Where it comes from: Donor tissue
Commonly reported trade-off: No harvest site on the person’s own leg; reported to fail at a higher rate (Dr Pai’s guide)
What it means for rehab: Rehab follows the surgeon’s protocol

Synthetic graft, such as LARS

Where it comes from: Synthetic material
Commonly reported trade-off: Higher failure rate and knee inflammation reported (Dr Pai’s guide)
What it means for rehab: Rehab follows the surgeon’s protocol

The surgeon's choice of graft depends partly on the patient's age, the sport they play and any previous knee injuries. Their own experience with different grafts also plays a part.

Planning ACL surgery? Book a prehab assessment.

Prehab Before ACL Surgery

Before ACL surgery, physio can help get the knee moving and working better again. That means reducing swelling, getting the knee fully straight and rebuilding quadriceps strength. Anyone who hasn't seen a physio since their injury can start with a knee injury assessment.

Prehab generally includes:

Reducing swelling in the knee joint
Getting full knee extension back
Working on quadriceps activation and strength
Practising walking without a limp
Learning to use crutches and preparing for the first days at home

A 2020 review of prehab research found that patients who exercised before ACL reconstruction had slightly better quadriceps strength and hop test results three months after surgery. The researchers only had a small number of trials to work with, though, so the evidence is still limited.

ACL Reconstruction Rehab Stages

Each stage starts when the knee meets the milestones of the last one, rather than after a set number of weeks. The timeframes below are general ranges. The surgeon’s protocol and the knee’s own progress set the real pace.

Early Recovery After ACL Surgery

In the first few weeks after ACL surgery, the physio checks how much swelling is still around the knee and whether it can straighten fully. Getting the quadriceps working again is another early priority. Exercises begin once the knee has settled enough after surgery, while crutches or other walking aids are used until walking improves (Healthdirect). The surgeon gives instructions on weight bearing. At this stage, progress might be as simple as holding a quadriceps contraction for longer or getting a little more knee extension back.

Strength and Control

Between 6 and 12 weeks after ACL reconstruction, there's usually more movement in the knee, but the operated leg still needs strengthening. A stationary bike can help with getting the knee bending again. The physio also introduces balance work and exercises that put more weight through one leg at a time. Strength is checked against the uninjured leg as rehab progresses.

Running and Agility

Running in a straight line may be introduced from around three months after ACL reconstruction, provided the knee has enough strength and control. Turning quickly and landing from a jump take more work. The physio brings these movements into rehab gradually, particularly for people returning to football, netball or basketball, where stopping and changing direction are part of the game.

Sport-Specific Training

Later in ACL rehabilitation, training becomes more demanding, with the physio checking how well the knee handles movements at the speed and intensity needed for sport. Strength and movement tests help track progress. Strengthening continues during this stage, with Clinical Pilates available at the clinic to work on control and muscle strength.

Book an ACL Rehab Appointment | Call (03) 9836 1333

Returning to Sport After ACL Reconstruction

Returning to sport after ACL reconstruction takes more than getting back to running. Someone may feel comfortable jogging in a straight line but still find it difficult to land on one leg or turn quickly. The physio checks these movements, along with leg strength, hop test results and confidence, before discussing a return to play with the surgeon.

The advice from Dr Pai's ACL guide is to wait at least 12 months before playing competitive sport again. Returning before nine months has been linked to more repeat injuries, while passing return-to-play tests is associated with a lower risk. Our sports injury physio team also checks strength and movement before someone gets back to their sport.

ACL Rehab at Eastside Physio + Co in Surrey Hills

Our physios at Eastside Physio + Co in Surrey Hills see patients both before and after ACL surgery. Ben Bailey has a particular interest in ACL and lower limb rehab. Rosie Phelan has also worked with patients recovering from ligament reconstruction. Later in recovery, Clinical Pilates may be included as part of their exercise program.

There's no need for a referral to book an appointment.

Our clinic is at 427 Canterbury Road in Surrey Hills, with patients coming from nearby suburbs including Box Hill, Camberwell, Canterbury, Balwyn, Burwood and Hawthorn. To arrange an appointment, book online or give us a call on (03) 9836 1333.

Book an ACL Rehab Appointment | Call (03) 9836 1333

ACL Surgery FAQs

Is ACL Reconstruction a Day Surgery?

Most people having ACL reconstruction go home on the day of surgery or the following day, according to Healthdirect. The hospital and surgeon will confirm the arrangements beforehand.

Is Surgery Always Needed for an ACL Tear?

An ACL tear doesn't always mean surgery. Some people do well with physiotherapy alone, particularly if their knee is stable enough for the activities they enjoy. The surgeon and physio look at the injury and the person's goals before discussing treatment. There's more about choosing between surgery and rehab on our ACL injuries page.

When Does Walking Start After ACL Surgery?

Walking usually begins early, with crutches or another walking aid for support. These are used until the person can walk well enough without them, following the surgeon's instructions (Healthdirect). The physio works on restoring a normal walking pattern during early rehab.

Is a Reconstructed ACL Stronger Than the Original?

An ACL graft doesn't immediately have the same properties as the original ligament. It changes and remodels over time. A review by Claes and colleagues found that this process was still taking place years after surgery. That's one reason ACL rehabilitation continues for many months.

How Successful Is ACL Reconstruction?

Results vary from person to person. Age, the demands of their sport, other injuries in the knee and progress through rehab can all affect recovery. The orthopaedic surgeon can explain the likely outcomes for each patient.

Is a Referral Needed for ACL Rehab Physio?

No referral is needed to book at Eastside Physio + Co. Our first appointment FAQs explain what else to expect.