I Tore My ACL This Winter...Now What?
I don't need to tell many of you that this last year was a fantastic ski season. For me personally, it meant watching close up and personal as Mikaela Shiffrin made the leap from slalom queen to overall champion, capturing the overall World Cup title. Not to mention, I snagged some great powder myself with family and friends in the Vail Valley and Summit County.
Unfortunately some you did not escape this winter without tearing the dreaded ACL, or "Anterior Cruciate Ligament". I know, because I saw a few of you.
The ACL provides our joint with stability for all of our rotational sports, so how it heals will be crucial not only to getting back onto the hill, but for all of your activities this year.
So you tore your acl..now what? Let's talk a bit about it.
This stability that we're talking about is more than just a "trust" issue of the knee. The ACL protects the meniscus (or cushion cartilage) caused by shear and twisting. In turn, the meniscus protects our joints from developing arthritis.
This last function is why so many people in Colorado choose to have their ACL fixed, once it is torn. Having arthritis of the knee is a sure way to throw a wrench in your plans to score some serious vertical on the slopes.
The decision to fix the ACL in a patient has become more a function of their desired activity than anything to do with age. Let's take Vail, for instance. How many other places do you know that have as many 70 year olds trying to ski 70 days in a year?
Your EPIC pass now records your vertical feet skied, encouraging you to get over a million feet before the end of the season. Your epic pass doesn't care how old you are.
With all of this great snow, unfortunately, comes some injuries to the knee ligaments.
Replacing the ACL
So, now you have had your ACL replaced, usually either with:
- Some of your own tissue, called an autograft, or
- A cadaver graft. This is also known as an allograft.
After surgery, there was probably a fair amount of pain, but your surgeon kept encouraging you to "work on range of motion, get the swelling down, and eliminate the risk of scar tissue forming."
You finally graduate from the "range of motion" segment of rehab and get on with the strengthening. It's a little bit easier than you thought it would be, but harder to get your strength all of the way back.
Your surgeon wonʼt let you turn to sports until you are fully rehabilitated, right?
The most common question I get is "When am I allowed to get back to unrestricted sports?” The answer is not an easy one. For me, return to sports has always been a combination of rehabilitation and biology. Here's a short video that may shed some light upon the topic.
THE BIOLOGY OF THE ACL
First the Biology. I'll try keep it simple and not to lose you to boredom. Whatever we replace the ACL with must undergo "remodeling", which is a fancy way of saying that it must get weaker before it gets stronger. Your body must grow new blood vessels into the new ACL. These blood vessels take away the old graft fibers, leaving a weakened scaffold.
Next new "ACL cells" get deposited down on the scaffold, making a better or stronger ACL graft, but this takes >9 months to accomplish. This scaffold phase is when the new ACL graft is at it's weakest. The new ACL may be less than half of its original strength 8-12 weeks after surgery. With modern surgical techniques and graft choices, the ACL operation just doesn't hurt as much as it used to.
Along with the great therapists we have access to, I know we can get an athletes back up to full strength 3 months after surgery, but that may not be a smart decision based on the Biology present.
If return of strength were the sole criteria for returning to sports following an ACL operation, ACL injuries would no longer be even season ending injuries! Needing the graft to re-model, we are not in a rush to get strength back as an early priority.
The functional sport test
Returning to Sports following ACL reconstruction is best accomplished once normal range of motion is achieved, the graft is strong enough, and the surrounding muscles are strong enough.
Once the knee looks normal, I use the measurement of thigh circumference 15 centimeters above the knee cap as a gross measure of strength and compare it to the other knee.
As we get <2 centimeters difference, we are approaching normal values that may actually be faking within measurement error. Once symmetric strength has been achieved, and we are more than 6 months after surgery for an autograft, or 9 months after surgery utilizing a cadaver graft, Functional Testing will help determinate if the athlete is ready to safely return to sports.
the ideal functional test
The ideal functional test will:
1. Test strength of the muscles about the knee
2. Test the athlete's endurance
3. Test agility, trust, and the ability to "accept a load" and
4 . Be safe. Failing the test should not put the knee at risk.
More about the functional SPORT Test #ACLrecovery #ACLtest
We have modified our functional SPORT test over the years. This functional testing is now utilized by the US Ski Team to determine when their athletes are able to start a "return to snow progression" safely. If there are any problems with the knee accepting a load, I want to know about it in the controlled environment of a therapistʼs office, rather than on the hill.
Functional SPORT Test
1. Forward Running with Cord resistance - 1 minute
2. Backward Running with Cord resistance - 1 minute
3. Side to Side Agility with Cord Resistance- 1 minute
4. Single leg knee dips with Cord - 3 minutes
Recreational Sports can typically start at 4-6 months after surgery, while competitive sports average 6-9 months.
Returning to Sports after tearing your ACL is tough; its hard and itʼs a process. What it is not, is an arbitrary time to return.