ACL Injury and Healing
- The “Static stabilisation” of the Knee
- The “Functional rehabilitation of the Knee”.
- Regaining confidence
- Sport and Activity selection
- Ongoing monitoring and risk mitigation

The 5 Parts to ACL Injury and Returning to Pre-injury Activities and Sports
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This information is not a substitute for advice from your doctor, nor does it contain all the relevant facts. Your doctor will consider your personal circumstances. Please talk with your doctor about any concerns.

The anterior cruciate ligament (ACL) runs diagonally in the middle of your knee and is responsible for preventing your tibia from sliding out in front of your femur, as well as providing rotational stability to your knee. The ACL is one of the most common ligaments to be injured.
1. The “Static stabilisation” of the Knee
We all have an ACL for a reason. It is a very important stabilising ligament for the knee joint. The ACL, like all ligaments of joints, acts as a “static stabiliser”.
After rupturing your ACL the ideal outcome moving forward is to protect your knee from future instability by “giving back” the patient this most important ligament by either healing the ACL, or surgically repairing or reconstructing the ACL.
These differing approaches will depend on the type and severity of your injury, the timing from ACL injury to diagnosis as well as personal choice and circumstances.
Non-surgical treatment
- Spontaneous healing of the ACL by adopting rehabilitation alone.
Only a small minority of ACL injuries heal adequately with this approach where nature (adequate static stabilisation) is restored with meaningful ACL healing. Unfortunately most patients who undertake this recovery method will need to adjust their subsequent level of activity or sport. That is, they need to adapt their activities as the knee may continue to “give way” if they return to high-demand sports. Repeated “giving way” may cause further damage such as meniscal or articular cartilage injury.
- Cross Bracing Protocol (CBP)
This is a 12-week protocol of bracing the knee to facilitate the natural healing of an injured ACL, followed by a period of rehabilitation. This recovery method is suitable if your ACL injury is mild to moderate, as determined by MRI diagnosis, and you are within 2-3 weeks of your injury date (ideally 4 to 7 days). After 2-3 weeks the ACL healing will NOT be facilitated by this method. The aim of the Cross Bracing Protocol and ACL healing is to regain static stability and return to full ACL competence of the knee.
Surgical Treatment
- ACL surgical repair : the acute surgical repair of the ACL.
This is an evolving area of surgical management of an acutely injured ACL and should be discussed with your surgeon to determine if this is a suitable approach to your condition.
- ACL reconstruction of a ruptured ACL.
This procedure is performed by an expert specialist Orthopaedic Knee surgeon replacing the injured ligament with a graft, the graft being usually from the patient’s own hamstring or patella tendon. This is followed by a period of rehabilitation, before aiming to return to pre-injury activity. This approach is not limited by time since injury.
Note: For all treatment options above it is estimated it will take up to 12 months for your healing ACL to fully mature and 12-months for your ACL graft to heal and biologically integrate in order to achieve maximum strength of this “static stabilizer of the knee” to allow a safe return to sport.

2. The “Functional rehabilitation of the Knee”.
This step is a most critical component of recovery, which will be led by your physiotherapist.
You will navigate a staged rehabilitation aimed at restoring your pain-free range of motion, strength and joint proprioception. Proprioception is the neurological ability that allows your brain and nerves to sense and control the position and motion of your joints, muscles and balance.
After a period of rehabilitation, you will return to running, pivoting/jumping/landing and agility. You can then return to training before unrestricted return to all activities, full training and eventually competition. Like the healing of the ACL and ACL graft this rehabilitation time is recommended to be a 12-month program from the date of ACL surgery or adopting non-surgical management (rehabilitation alone or CBP).
3. Regaining confidence
After an ACL injury, and subsequent adoption of a non-surgical or surgical management pathway, you may suffer anxiety and fear of re-injuring your knee.
This is your brain’s response to the experience of your injury itself and your extended recovery over many months. This is not uncommon.
Your doctor and physiotherapist are acutely aware of this psychological phenomenon and will guide you through this step by step slowly restoring your knee function and gradually reintroducing pre-injury activities and sports. With every step you will gain greater and greater confidence and in turn erase the anxiety.
4. Sport and Activity selection
Getting back to what you love doing...
Once you have gone through your rehabilitation program, you will then have a choice to either return to your pre-injury activities and sports, or choose to adopt activities and sports that carry less risk of future ACL injury. This of course is a very personal choice.
Those sports with high ACL injury risk include:
skiing, football/soccer, AFL, rugby league, rugby union, touch football, Oz tag, netball, basketball, martial arts, mountain biking, motor cross, gymnastics
Sports with low ACL injury risk:
swimming, cycling, kayaking, rowing, paddleboarding, jogging, yoga, Pilates, cross country skiing
5. Ongoing surveillance and risk mitigation
Once you have undertaken your 12-month recovery program, including comprehensive rehabilitation, you will need to focus on minimising your risk of further ACL injury.
This is especially recommended if you:
- Sustained a non-contact ACL mechanism of injury.
- Have a strong family history of ACL injury.
- Are returning to sports and activities associated with a high risk of ACL injury.
You will need to identify and mitigate all modifiable risk factors for ACL injury. Your physiotherapist and doctor will help you with this. By continuing strengthening and agility exercises in the long-term, you can work towards reducing your ACL risk, and also improve your sporting performance.
By following these 5 recovery steps, you will maximise your chances of returning to your chosen sport and activities in a safe and enjoyable way.