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acl injury & acl treatment

ACL Injury Treatment & ACL Rehab

An ACL Injury is one of the most feared injuries in sports.

Ask any basketball, soccer or footy player about their greatest nightmare and other than missing the shot after the siren, it’s a dreaded ACL injury.

A tear of the ACL is often thought to be a career-ending injury.

In the past, few professional athletes returned to their pre-injury performance level. And it was also thought if you’d like to return to sports, an ACL reconstruction was the only way to go. 

Even for an average punter called Dominic out there. Someone with no plans of returning to high-level sports might have been recommended to have an ACL reconstruction as a means to reduce the chance of knee osteoarthritis.

Fortunately, the science around ACL injuries has evolved much over the past decade. We now know that the prognosis after an ACL tear is not as bad as we initially thought. Even better news is that they may not always require surgery.

Like many injuries across the body, with quality active ACL rehabilitation alone you will be able to regain good function.

In this article I’m going to cover all the ins and outs of an ACL injury including:

  1. What exactly is an ACL
  2. The causes of ACL injuries
  3. The symptoms associated with ACL tear
  4. Other associated injuries
  5. Treatment options
  6. If you need a surgical reconstruction
  7. Active rehabilitaton
  8. The operative pathway
  9. Return to sports

Before we get started what exactly is the ACL?

The ACL; A.K.A the Anterior Cruciate Ligament (not so crucial actually) is one of 4 ligaments which surrounds your knee.

The ACL connects the thigh bone and the shin bone.

Its primary role is to provide passive restraint, preventing the shin bone from sliding ahead of the thigh bone. 

what is a ligament and what do ligaments do?

Learn all about ligaments in our Anatomy Class Series here.

And what causes an ACL tear?

An ACL tear can occur with:

  • Sudden changes in direction such as cutting and pivoting maneuvers
  • When landing or falling with the knee bent inwards or backwards
  • High impact collision to the knee from the inside or outside

What would you expect after an ACL injury?

Someone who experienced an ACL tear will often report:

  • “Popping” sensation in the knee
  • Pain and inability to continue activity
  • Swelling around knee within 2 hours
  • Loss of knee range of motion
  • Sensation of the knee giving way when weight bearing

An ACL injury seldom occurs in isolation. You can also get a:

  • Meniscus lesion 
    • The meniscus serve the role of shock absorbers for your knees and help keep your knee joint slippery and mobile 
    • A lesion of the meniscus may result in clicking/locking of the knee joint
  • MCL/LCL injury
    • The MCL is the ligament by the inner side of your knee which resist inwards buckling whereas the LCL is located along the outer knee and help resist outwards buckling
  • Posterior lateral corner injury
    • Containing tendinous and ligamentous structure which resist outwards rotation of the shin bone
  • Cartilage injury
  • Fracture of the joint surface of the shin or thigh bone

What should you do next?

Get your knee examined by your physiotherapist or GP

Tests will be conducted to examine the integrity of your knee jointrange of motion, strength and control of your movement

For a suspected ACL injury, an MRI examination of your knee may be required to rule in/out other associated injuries.

Treatment for an ACL Injury

Contrary to popular belief, not all ACL injuries require surgical reconstruction. 

You might to be surprised to find out that: 

  1. When managed with early controlled mobilisation, an ACL that is partial or even completely torn can heal without surgery
  2. Latest research that compared active rehab in suitable candidates and ACL reconstruction surgeries found no difference in terms 
    • Quality of life
    • Pain
    • Symptoms and function 
    • Return to sports level
    • Subsequent meniscus tear 
    • Radiographic Knee OA

When should surgery be considered?

  1. Non-resolving episodes of knee instability despite ongoing active rehabilitation
  2. It is also worth noting that there is no harm in delaying ACL reconstruction as it makes no differences in the knee function at 2 and 5 years 
  3. In the presence of significant associated injuries

Now it’s important to understand, with an ACL injury there is no easy way out.

Regardless of treatment choice between active rehabilitation or ACL reconstruction.

Your outcome will be better with at least 5 weeks of supervised high quality rehabilitation. 

Tell me more about ACL Rehabilitation then! 

Non-operative pathway

Your physiotherapist guide you through a criteria-driven active rehabilitation pathway that addresses the following

  1. Pain, swelling and knee range of motion
  2. Knee strength and control
  3. Capacity to withstand
    • Running
    • Jumping
    • Landing
    • Sports-specific loading
  4. Graded return to training and sports

A sample of the exercises can be seen here and here.

And by the way, optimising your squat mechanics for your sore knee is going to help avoid overloading it. Check out this guide below.

Operative pathway


  • A good surgeon will recommend a ACL prehab prior to ACL reconstruction surgery in most cases
  • Studies have found that reduced pre-operative knee swelling and improved quadriceps strength is associated with better post-op outcomes. Both of which can be gained with pre-operative rehabilitation, or PREHAB.


The general rehab principle for non-operative and subsequent operative management for ACL injury are very similar. However, some rehab adjustments are required depending on graft selection and individual healing characteristics

  • Patella Tendon Autografts
    • Pros: Robust, less chances of requiring a revision, recommended for high demand athletes, shorter graft healing 6-8 weeks
    • Cons: Risk of post-operative pain behind the knee cap, early knee joint osteoarthritis, slight increased risk of post-operative knee stiffness
  • Hamstring Tendon Autographs
    • Pros: Less post-operative stiffness issues, faster recovery time
    • Cons: decreased hamstring power, 8-12 weeks for graft healing
  • Synthetic Grafts
    • Pros: no graft donor site injury, suitable for athletes with event within 6 months for quicker return to sports, option for revision later
    • Cons: risk of graft failure and synovitis
  • Allografts: Taken From Cadavers
    • Pros: option for patients who have failed ACL reconstruction before, minimal risk of infection
    • Cons: less stiffness compared to autografts

Returning to sports after an ACL injury

The majority of people are able to return to exercise and participation in sports after an ACL injury. Individuals who have greater quads strength, less knee swelling/pain, better confidence, less fear of movement, motivated to engage in rehab are found to manage better.

A broad sample of individuals with ACL injuries found the following:

More than 50% of active patients with an anterior cruciate ligament (ACL) injury who undergo active rehabilitation alone have successful 2-year outcomes and comparable knee function to an uninjured population

Post ACL reconstruction, around 65% of recreational athletes would be able to return to the same level of sport compared to 83% of professional athletes. 

Individuals who are unable to return to sport at the same level despite rehab or reconstruction can consider participating in sports which have less athletic demands. 

Current clinical guidelines recommend the following prior to returning to sports:

  • Less than 10% deficit in strength of the quadriceps and hamstring 
  • Less than 15% deficit in lower limb symmetry on during hopping tests
  • Reduced/absent of swelling
  • Pain-free range of movement
  • Full knee ROM
  • Fewer episodes of self-reported knee instability
  • Improvement in self-reported knee function and activity related phobia 

If you are interested to find out more about ACL injury management you can book for a telehealth or in clinic session with our physios.

acl expert physiotherapist dominic tan

See you soon! – Dominic


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