Anterior cruciate ligament tears of the knee are, unfortunately, extremely common. Currently the immediate recommendation following confirmation of an ACL tear is to have surgery to reconstruct the ligament. This is done with use of a tissue graft (typically your own - patellar tendon, hamstring tendon, or quad tendon, or a cadaver graft). Which graft is used is another topic of conversation - but in short - using your own quad or patellar tendon seems to be the strongest and thus utilized in younger, more active people, while cadaver grafts are used with an older population as initial phases of recovery are easier and they are not as reliant on the strength of the graft.
Some people opt to NOT have surgery following an ACL tear - leading to the question, can we function without an ACL? Another question that is being investigated is, can the ACL heal itself?
Currently - when people choose to NOT have surgery, they will go through rehabilitation and find out if they become a “coper” or a “non-coper”.
A coper is identified as an individual who restores normal level of function with an ACL-deficient knee. They no longer have the ACL ligament but their body does not seem to miss it.
A non-coper is identified as an individual with an ACL-deficient knee that does not restore function and continues to feel instability of the knee. These individuals typically will go on to have ACL reconstructive surgery.
Rehabilitation for an individual who wants to find out if they are a coper or non-coper is multi-factorial as any rehab program is. Build the leg muscles (e.g. quad, hamstring, gluts, calves, etc), build back balance, build back function, build back fitness. See how far you can get to restore normal function and you’ll have your answer if your body can cope or not.
In 2019, the ACL-heal project commenced. This is on-going research with extremely positive results. Dr. Tom Cross and Dr. Stephanie Filbay are amongst the lead of individuals working on a bracing protocol with individuals who have torn their ACL, the Cross Bracing Protocol - that shows that over 90% of ACLs can HEAL themselves when given the opportunity to do so. They have been able to identify patterns on MRI that show how likely the bracing protocol is to work. This is tremendous - as the way we recommend treatment prior to this is - “Your ACL won’t heal and we’ll find out if your body can handle that or not”.
The research is building in this area - but the Cross Bracing Protocol is here and it looks like it will be entering the stage with a bang. It involves a period of time that the knee is braced/immobilized to 90 degrees of bend (Flexion). Anatomically - this is where the ends of the ACL can actually communicate best - thus allowing them to start to heal together. The theory is that of reduction - just as fractures are treated. If you put the ends of the bone close together and cast them, they will communicate and heal the fracture.
The Cross Bracing Protocol is 12 weeks in length (for the brace), the initial 4 weeks are immobilized at 90 degrees, the following 8 weeks the brace is given more motion every 1-2 weeks until full. At 12 weeks - the individual has another MRI to show the level of healing of the ACL. Once allowed full range of motion - rehabilitation would continue to restore back to the previous level of function. Rehab still is likely to be 9-12 months long, but without surgery and rehab is performed all while the brace is on to minimize loss of muscle and fitness.
There are certain things to take into account when adopting the bracing protocol - including is the person a candidate (based on MRI findings - type of ACL tear as well as if there are other tissues injured), can the individual get on an prophylactic anticoagulant (due to being immobilized) and are they at high risk for a blood clot.
Another important factor is that of TIME - time to diagnosis, time to get them braced. The earlier, the better (once the person can reach 90 degrees on their own). This means the individual needs to 1) get to a clinician for evaluation (PT/urgent care/physician), 2) get an MRI scheduled and results. The window for bracing is 14 days. After 14 days the protocol is not recommended.
If an ACL tear is suspect, the individual can be braced 90-30 degrees while awaiting results, and trying to spend most of their time at 90 degrees (sitting around, etc). Some people even are trying hybrid versions of the bracing so they can function (e.g. will brace 90-30 when driving so they can still be independent, but then spend the rest of the day at 90).
The conservative care for ACL injuries is soon to be a hot topic and an exciting option for those - of any level - elite athletes to those living a seemingly “normal” daily life - who wish to avoid surgery and heal the ACL.
I had the honor to connect directly to Dr. Tom Cross who is and will continue to help navigate these cases as the research builds. If you are considering conservative care - it is likely many physicians and PTs will not know of this protocol simply because the work will not be published until later in 2023, but the data is ready! If you find yourself having questions, please feel free to contact me at email@example.com.