Anterior Cruciate Ligament (ACL) injuries are a common knee injury that we see in the clinic. While most people have some knowledge of what an ACL injury is, there are new options for management / treatment of these injuries other than the conventional surgical repair.
What is the ACL?
The ACL is one of the major ligaments which helps stabilise the knee joint. It has attachment points from the femur (thigh bone) to the tibia (shin bone). Common ways in which this ligament can be torn involve sports or activities where there is rapid rotation, twisting and pivoting around the knee. Hyperextension of the knee joint can also result in a tear of this ligament.
Patients usually report a mechanism similar to that above, along with a popping sensation, which may be followed by swelling in the knee joint.
Are all ACL tears the same?
The ACL can be torn/ ruptured at one of 3 locations
- femoral origin
- tibial insertion
- in the middle, known as a mid-substance tear
This image shows an intact ACL compared with a ruptured ACL.
ACL Surgical Repair
Gold standard treatment of ACL ruptures has been surgical repair with the use of some form of graft, either a hamstring graft, patella tendon or donor graft. This was mainly due to the hypothesis that ACL cannot heal by itself.
More recently however, there have been many cases of people showing spontaneous healing of their ACL ligaments without surgical intervention. This has been a poorly understood concept for quite some time as we did not know why this would occur in some, and not others.
Non Surgical Management of ACL Rupture
The advancements in non surgical treatments and rehab protocols have now led to the development of the novel Cross Bracing Protocol (CBP) which may facilitate the healing of a ruptured ACL, without surgical intervention.
Dr Tom Cross has been trialing a bracing method which keeps the injured knee bent at 90 degrees in a brace. The theory being that when bent at 90 degrees the shorter distance between the tibia and femur may allow the torn ligament to heal.
However not all ACL injuries are suitable for the CBP. As previously mentioned, the ACL can tear in one of three ways. Research has demonstrated that a midsubstance ACL tear has the best chance of healing with the CBP. In the same research, tears that were from the tibial and femoral attachment points did not have satisfactory healing.
It was also shown that the bracing protocol needed to be commenced within 4 weeks from injury in order to be successful.
Complicating factors
Unfortunately if the patient also presented with the following they were deemed not suitable for this management:
- Displaced bucket handle meniscus tear
- Severe postero-lateral corner (PLC) injury
- Osteochondral loose bodies
Research outcomes
Results published by Dr Cross and his colleagues found that keeping patients who met the inclusion criteria for the CBP, in a brace locked at 90 degrees knee flexion, weaned out over a period of 12 weeks, had a 90% success rate.
What is success in this scenario? At a follow up MRI at three months, healing was displayed of their ACL.
While this research is still in its early days, this new strategy means that patients may have the option to choose a non-surgical strategy, and in doing so avoid all of the potential consequences and adverse impacts of surgery.
We look forward to future studies which will follow up on the integrity of the ACL in those following the CBP, along with the success of these patients in returning to sport – however early results are quite promising.
Our team have supported patients using the Cross Bracing Method (in additional to post ACL surgery rehab). Please reach out to our team if you have any questions.
