ACL injuries are one of the most infamous and prevalent sporting injuries in the world.
Surgery has traditionally been the first course of action taken in the case of ACL injuries in Australia in recent years. This is due to the commonly held belief that ACLs cannot heal naturally after a rupture. However, new research may be challenging this long-held idea.
The KANON trial (Filbay et al 2023) showed that there was “MRI evidence of ACL healing at 2-year follow-up was observed in 16 of 54 (30%, 95% CI 19 to 43%) participants randomised to optional delayed ACLR. Excluding participants who had delayed ACLR, 16 of 30 (53%,
36–70%) participants managed with rehabilitation alone displayed MRI evidence of ACL healing”.

This has been expanded upon with the recent implementation of the Cross Bracing Protocol,
designed by Mervyn and Tom Cross. They have shown using their protocol a success of 90% ACL healing at 3 months post-injury (ACLOAS Grade 1: 50%, Grade 2: 40%, Grade 3: 10%)(Fillbay et al, 2023).

These findings are significant as there is a large financial burden, both personal and governmental, with ACL surgery. “The estimated cost of ACL reconstructions for amateur football players is $69,623,211 with a mean total cost of $34,079”. (Ross, A. G. et. al, 2023). If alternative methods could be found that remove this need for surgery, at cheaper costs, this could be significant in removing the financial burden of patients and the healthcare system.
The principle behind the Cross Bracing Protocol, which can be attributed to the higher rate of re-union than spontaneous healing, is the fixed position of the knee in flexion. This position creates the best chance of a ligamentous union between the torn fibers, as “the distance between the ACL origin to its insertion is shortest at 90°–135° of knee flexion.” (Jordan SS et al, 2007). The
Cross protocol uses a fixed brace at 90 degrees flexion for 4 weeks, then over 8 weeks, the range is slowly expanded to allow a full range of motion. This gives the time for the ACL to reattach and has shown promising initial signs of success.

An issue that occurs with both ACL surgery and the cross-bracing protocol is the relative time of inactivity can cause significant atrophy in the lower limb musculature, namely the quadricep muscles, a key muscle group for knee stability. In the study performed by Shen et al (2024); ”the odds of knee pain decreased with every 20 N/m increase in quadriceps strength (odds ratio,
0.87; 95% confidence interval, 0.81-0.94)”. Individuals in the upper quartile of quadriceps strength had lower odds of knee pain than those in the lower quartile”. In surgery, any graft site, including the hamstring or patella, will also create strength loss in those areas, which can create
complications and more work through the rehab process. The cross-bracing mitigates this slightly. After 4 weeks, you can resume a graduated rehab protocol, but the early time frame loss is still significant.

The other problem with the cross-bracing method is that being in a fixed flexion brace for 4+ weeks is unfeasible for some people. This can be for a variety of reasons, including financial reasons (inability to continue working), need for care (of self or others) limited by the brace, or
medical (due to fixed position any person with a history of DVT is ineligible for bracing).

The question then becomes, is there a way to simulate the bracing position, and use the same kinematic principles, through a guided rehab program, to provide an option for those for whom both brace and surgery are ineligible? Could this program create faster and more successful
healing rates than the naturally occurring healing rates seen in the KANON trial, and prevent the loss of quadricep strength in the key early stages post-injury?

The proposed clinical trial, using an exercise program designed by Marta A. Bandala of Back to Balance, would use her online program, administered as a home exercise program, to foster natural ACL healing using the same biomechanical principles as the Cross Bracing protocol. The HEP is designed to simulate knee flexion in the early stages of ACL healing, but still allow for knee movement while strengthening the quad and surrounding stabilising
musculature. This mitigates the losses to muscle strength and size in the early stages of injury, and it allows some load bearing and movement, as well as the movement of nutrients through synovial fluid, which transfers to joints using compression and expansion of the joint itself
through movement. This could improve the healing ability and quality of the ACL.

By using an exercise program specifically targeting these kinematic properties of the ACL we can create better healing than spontaneous rates in a faster time frame, for those where Cross-bracing or surgery are not viable options for intervention.
This HEP is a 12-month program designed specifically for ACL recovery and knee healing. This program is tracked using a variety of subjective and objective outcome measures to assess the healing of the ACL at each stage as well as the functional status of the knee. The cues and coaching for the program have been standardised to ensure consistent coaching to all potential test subjects, and the program requires no equipment other than a small pilates ball, so anyone at home can perform it without support. Progression is set using key outcomes and biomechanical measures to ensure subjects progress at a consistent but individualised rate.

So far, this program has shown an over 90% success rate when started within 8 weeks of the initial injury and has had clients return to sport between 6 and 12 months post-injury. A client I referred began this program 3 months post-injury, and while the status of the ACL is unknown,
they were able to return to skiing 11 months post-injury, with a high ACL-RSI score of 80%.

Testimonials and imaging for current clients who have done the program within the 2-month
window are attached as references. The clients display high levels of clinical knee stability and functional strength, with high levels of confidence in returning to pre-injury activity.

For the program, initial coaching is performed in person or through a telehealth consult by Marta. Follow-up consultations are performed at periodic intervals to ensure exercise technique is correct and ensure accountability of the subjects.

Periodic testing for outcome measures is done at 1 month, 3 months, 9 months, and 12 months post-injury. Testing would include an MRI, where ACL healing and quality would be assessed through the use of the ACL OsteoArthritis Score (ACLOAS). The KOOS and ACLQoL questionnaires will be used to assess the subjective quality of life and function of each subject.
Ligament strength and knee stability would be assessed through practitioner application of the Lachmans test and pivot shift test. Objective testing would also be performed to track progress, using ROM, dynamometry, and functional assessments using the VALD force decks to assess
asymmetry and movement patterning changes throughout the rehabilitation process. These tests could be standardised to be implemented at any physiotherapy practice with the necessary equipment.

Evan Adair- APA Titled Physiotherapist
Senior Physiotherapist at Active Back Care
AHPRA Number: PHY0002146701
Mobile: 0415501519


Marta A. Bandala
Back To Balance Pilates Studio Founder
Mobile: 0433778880
Email: studio@backtobalancepilates.com