ACL Healing And The "Cross Bracing Protocol": A Revolutionary Approach To Recovery
Anterior cruciate ligament (ACL) ruptures are a common sports injury that often require surgical intervention. However, recent research suggests that the ACL may have the potential to heal on its own, without the need for surgery…
What Is ACL Natural Healing?
Traditionally, surgical intervention has been the standard treatment for ACL ruptures, involving reconstruction of the torn ligament. However, recent research has revealed the potential for the ACL to heal on its own, without the need for surgery. This has sparked interest in exploring non-surgical management strategies that promote ACL healing and improve patient outcomes.
One such strategy is the Cross Bracing Protocol (CBP), developed by Dr. Tom Cross right here in Sydney, and which our physio, Josh, was a part of in its initial 80 patients and the creation of the physiotherapy rehabilitation program design!
The ACL bracing protocol utilizes a novel bracing technique to support the healing process. This is an exciting development that could change the way ACL injuries are managed. So we will break it down for you and delve into the recent milestone study that investigated MRI evidence of ACL healing, patient-reported outcomes, and knee stability in the initial 80 individuals managed with the CBP.
The Study: ACL Bracing Protocol & Non-Surgical Management With The CBP
The 2023 study from Filbay et al., examined the MRI evidence of ACL healing and patient-reported outcomes in individuals with acute ACL rupture who were managed non-surgically with the acl bracing protocol called the Cross Bracing Protocol (CBP). The study found that 90% of patients had evidence of ACL healing on MRI at 3 months, and those with more ACL healing had better outcomes.
The Cross Bracing Protocol (CBP)
The CBP is a novel bracing protocol that aims to facilitate ACL healing by reducing the gap distance between the torn ligament remnants. The protocol involves immobilizing the knee at 90 degrees of flexion for 4 weeks, followed by progressive increases in range of motion until brace removal at 12 weeks. The protocol also includes physiotherapist-supervised rehabilitation to improve lower limb function and return to sport.
The protocol combines the use of the specialised knee brace with tailored physiotherapist-supervised rehabilitation. Let's take a closer look at each component of the CBP:
1. Knee Brace: The CBP involves the use of a knee brace that is specifically designed to support the knee joint during the healing process. The brace is applied within the first few weeks following the ACL injury and is worn continuously, even during activities such as sleep and showering. It is set at a fixed angle of 90 degrees of flexion to immobilize the knee and reduce stress on the torn ligament.
The brace serves two main purposes: First, it helps to minimize movement and provide stability to the knee joint, allowing the torn ACL to heal. Second, the angle of knee flexion (90 degrees) chosen for immobilization is believed to reduce the gap distance between the torn ends of the ligament, promoting tissue bridging and healing.
2. Physiotherapist-Supervised Rehabilitation: In conjunction with the bracing, patients undergo a structured rehabilitation program guided by physiotherapists. The rehabilitation program aims to improve lower limb function, enhance neuromuscular control, and gradually restore the range of motion in the knee joint.
The rehabilitation process typically starts with gentle exercises to promote muscle activation in the surrounding leg muscles. Over time, the program progresses to include strengthening exercises to rebuild muscle strength and enhance stability around the knee. Additionally, functional training activities are incorporated to improve agility, balance, and coordination. All of this is done in the brace for the first 12 weeks!
Throughout the rehabilitation process, patients receive regular guidance and support from their physiotherapist. These professionals monitor progress, provide feedback, and adjust exercises as needed to ensure optimal recovery.
The Findngs
The study included 80 patients with acute ACL rupture who were managed with the CBP. MRI evidence of ACL healing was assessed at 3 months and 6 months using the ACL OsteoArthritis Score (ACLOAS). The study found the following:
1. 90% of patients had evidence of ACL healing on 3-month MRI, with 50% graded as ACLOAS grade 1 (normal ligament with thickened or high intraligamentous signal) and 40% graded as ACLOAS grade 2 (thinned or elongated but continuous ligament).
2. Patients with ACLOAS grade 1 had better patient-reported outcomes, including higher Lysholm Scale scores (a measure of knee function) and higher ACL Quality of Life scores (a measure of knee-related quality of life), compared to patients with ACLOAS grades 2-3.
3. Patients with ACLOAS grade 1 also had less passive knee laxity, as measured by the Lachman's test and the Pivot-shift test, compared to patients with ACLOAS grades 2-3.
4. Patients with ACLOAS grade 1 had a higher rate of return to pre-injury sport (92%) compared to patients with ACLOAS grades 2-3 (64%).
The study found that 90% of patients had evidence of ACL healing on MRI at 3 months, suggesting that the torn ligament was repairing itself. This is significant because it challenges the conventional belief that the ACL has limited healing capacity. Patients with more ACL healing on MRI had better outcomes, including higher scores on measures of knee function and knee-related quality of life. They also had less knee laxity, which is an important indicator of knee stability, and a higher rate of return to pre-injury sport.
Implications for Patients & Clinical Practice
This research suggests that non-surgical management strategies, such as the CBP, which focuses on promoting ACL healing through a combination of bracing and rehabilitation, could be a viable treatment option for ACL ruptures. This is great news for patients who are hesitant to undergo surgery or who may want to explore conservative treatment options first. Non-surgical management with the CBP could potentially reduce the need for surgery and its associated risks and costs.
It's important to note that this study was a case series, which means it followed a specific group of patients and does not provide definitive evidence. Further research, including large clinical trials, is needed to confirm these findings and understand the long-term outcomes of ACL healing. However, the findings are promising and highlight the potential for ACL healing without surgery and provide hope for individuals who are reluctant to undergo surgery or prefer non-invasive treatment methods.
If you have recently experienced an ACL rupture, it is important to consult with a healthcare professional specializing in sports medicine or orthopedic surgery. They can provide a comprehensive evaluation of your injury, guide you through the available treatment options, and help you determine the most suitable approach based on your individual needs and goals.
ACL BRACING FAQs
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The short answer is no. Not everyone will be a candidate for this management option due to the specific sub-classification of their acl injury, due to other injuries sustained to the knee at the time of acl injury or due to inability to tolerate the bracing time line and its medical risks.
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First step will always be seeking medical advice and seeing your sports physician or knee specialist. They can refer you for the scans and tests required to help decide if you are a candidate.
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A total of 4 weeks is the current standard practice. This means you will be hopping around on cructhes, sleeping, eating and showering in your brace for that whole time!
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Yes it is safe, provided you are under the care of a sports physician and a supervising physiotherapist. There are risks like DVT that we mitigate throughout the process and your doctor will guide this. As for long term side effects, we don’t have enough long term data at present to know with certainty - but we know acl injury and acl surgery both lead to increased rates of knee osteoarthritis so we can assume there will be some similar changes from bracing following acl injury. But watch this space - hopefully natural healing with the CBP leads to improved knee OA outcomes by avoiding the trauma of surgery!
Conclusion
The prospect of ACL healing without surgery is an exciting development in the field of sports medicine. The recent study investigating the Cross Bracing Protocol provides evidence of ACL healing in patients managed with this non-surgical treatment approach. Improved patient-reported outcomes, reduced knee laxity, and a higher rate of return to pre-injury sport were observed in patients with evidence of ACL healing. While further research is needed, these findings suggest that non-surgical management strategies, such as the CBP, may be a valuable alternative to surgery for individuals with ACL ruptures. If you have suffered an ACL rupture, consult with a healthcare professional to explore all available treatment options and make an informed decision tailored to your specific circumstances and goals.
Gravity Physio on the Northern Beaches can offer guided rehab for patients undergoing this protocol once they have seen their sports physician.
All information and images are taken from, and belong to, the authors of the article. For more information read the article at BJSM by clicking the link:
Visit Dr. Tom Cross if you think you may be a candidate for bracing: