Non-Surgical Healing of ACL Ruptures

Non-Surgical Healing of ACL Ruptures – The Cross Bracing Protocol Results

In June 2023, a much-anticipated paper was published on the non-surgical healing of ACL ruptures. It has long been believed that the ACL has little ability to heal, leaving patients with the options of surgery to return to sport or giving up pivoting sports/activities altogether. However, a growing body of evidence is highlighting the healing powers of the ACL, providing more options for those with this common sporting injury.

In a previous blog post, Jamie discussed the Cross Bracing Protocol (CBP) developed by Dr. Tom Cross from Stadium Sports Medicine. For a more in-depth understanding of the study, I recommend clicking on this link (Bracing Protocol). In short, the study involved placing participants in a range of motion brace locked at 90° flexion for four weeks and then gradually increasing the range in the following weeks. The goal of this protocol is to create a “closed reduction” or the shortest distance between the origin and insertion of the ACL. By closing this gap, it is thought, the body has a higher likelihood of bridging the rupture and facilitating healing of the ACL.

The study found that 90% of participants showed signs of healing on MRI scans at three months. This was determined by the observation of continuity of the ACL on these scans. 50% of those in the trial had thickening and minimal damage to the ACL, while a further 40% of participants had an elongated but continuous ligament on MRI. These are all positive signs of healing. Furthermore, the greater signs of healing seen on the MRI scans correlated with greater function of the injured limb, higher rate of return-to-sport, increased passive knee stability and a better quality of life.

As with any study, there are inherent risks involved, and the CBP is no different. Of the 80 participants involved in the trial, 14 individuals experienced a re-injury to the ACL. Four of these individuals were in the group that had minimal damage to the ACL on scans. All re-injuries occurred after returning to sports. Additionally, two individuals developed deep vein thrombosis (DVT) and were conservatively managed.

It is incredibly important to note that the protocol was not just bracing. Physiotherapy made up the majority of the trial with different focuses throughout the trial. The aims of physiotherapy for the first 10 weeks were aiding ACL healing and remodelling. This included the brace period and was aimed at reducing muscle wastage, controlling of pain and swelling, increasing range (post 4 weeks) and improving strength and proprioception (where the limb is in space). The next 8 weeks allows for preparation and introduction of running, accompanied by plyometrics (rapid contraction of muscles e.g. hopping) and agility. From week 20, 6 weeks of training should begin. This is IF participants have cleared return to sport markers. From 26 weeks to 9 months, return-to-paly can begin. This process is individualised, and criteria driven.

Further follow-up studies will be published in the future of this exciting and novel study.

Filbay, S. R., Dowsett, M., Chaker Jomaa, M., Rooney, J., Sabharwal, R., Lucas, P., Van Den Heever, A., Kazaglis, J., Merlino, J., Moran, M., Allwright, M., Kuah, D. E. K., Durie, R., Roger, G., Cross, M., & Cross, T. (2023). Healing of acute anterior cruciate ligament rupture on MRI and outcomes following non-surgical management with the Cross Bracing Protocol. British Journal of Sports Medicine, bjsports–2023–106931–. https://doi.org/10.1136/bjsports-2023-106931