Episode 120 | How To Know If You’ve Torn Your ACL

Welcome back, team! Episode 120: How To Know If You’ve Torn Your ACL. Now, if you’re listening to this, you’re probably someone who is geeky and just wants to know about this. Or, you might be on the other side of this where you are actually someone who thinks you’ve torn your ACL and you’re trying to figure it out. In that case, I am so sorry I’ve done it twice myself. It is not fun, but I hope to put your mind at, I guess, ease. To be able to know and figure out, all right, maybe there is an ACL tear. Let’s just dive into this. Let’s set some context here. You have just had an accident playing a sport, skiing, soccer, jumping off a box, dodging someone, maybe going to grab your kid and you fell or you slipped, you name it. Wondering if you have torn your ACL. 

Today, the goal is to give you an idea of what happens to help the diagnosis of an ACL tear. Now, this is not medical advice, this is just educational. If you do suspect this, you do need to seek out medical help and professional help. Let’s just make sure we do the right steps here. This is just to help you get an idea. What are the things I’m looking for? Let’s dive straight in. People really do vary in terms of their own experiences when they suspect something like an ACL injury. You could hear the far extreme where someone has gotten into a contact-based injury where someone collides with them, to someone who just missteps off a curb.

No, seriously, like there have been people I’ve worked with where they’ve stepped off a curb and they tore their ACL and it sucks. Not the coolest story, but it happens. The experiences of that specific incident, when it happens, can vary a ton. There are a few things that people assume when an ACL tear happens, that this is typically how they will present or look like or feel, but really this can vary so much.

For example, I’ve torn both my ACLs, my ankle break in my left ankle, and my right shoulder dislocation where far more painful than my ACL tears. You would think the ACL tears would be more painful with the tear of the ligament and the way the injuries typically look. But in reality, the dislocation of my shoulder and my ankle break sucked and it hurts so much. And so that’s what people think a lot of times is that you need to be in a lot of pain in order for it to be an ACL tear. And that is not always the case. It could be just something as much as just like a step and then all of a sudden, yeah, there might be some pain or a shift.

But in that situation, sometimes people are just like, I don’t know, it was just weird like my knee shifted or I felt a pop, but I don’t know. Sometimes people fall to the ground or they continue going, and then they start to realize something is off. But it’s not always this traumatic, grabbing my knee on the field type of situation. And that’s probably what we picture in our minds because of watching sports and knee injuries. And you watch a soccer player or a football player go down and they’re usually grabbing their knee. And a lot of times that can be the situation and it is painful. But for some people, it’s not as painful as you would think. The reaction and the pain of the experience can vary a lot. 

Next up is people think you can’t get up and walk after an ACL tear. There have been plenty of athletes I’ve seen or clients and we have conversations about ACL tears. And sometimes they’re like, that’s definitely not an ACL tear. They can’t get up and walk after that. And you would be surprised how many people can. I hobbled off the field myself because I was like, all right, I don’t know what’s going on. I just can’t put enough weight on my knee right now. But I was able to still put weight on it and walk off. And the thing is, is that people have varying experiences with being able to walk after they tear their ACL. They might have that weird limp that they go on after. And there are some people who usually have more traumatic accidents where it is harder to walk on that knee. And so therefore they might have to be lifted or some friends have to help them or they might have to crawl their way to some sort of place in order to make sure that they’re supported.

The main point here is that people can walk after they tear their ACLs sometimes. And sometimes you’ll see people walk off a field and think it’s not one when it could be one. I will say as a generalization, it is painful. It just varies on the degree. And then in terms of walking, a lot of times people can’t walk as much after, or they have trouble weight-bearing, but it could still happen. These are just some of those things you can look out for. And assumptions that we often hear from people about the thought of ACL injuries and then actually how that matches up. So that can help put on the radar a little bit of, oh, well, it’s definitely not an ACL if I can walk or it isn’t painful. And then therefore you’re thinking no ACL, but sometimes it still can be. I just want to make sure that that doesn’t automatically mean ruling out because of those two things. 

Now, you’re wanting to know, how to know if you’ve really torn it. It’s going to take some detective work to figure it out. That’s basically physical therapy, any of this stuff in a nutshell. First, we have to start with the injury itself, what we call the mechanism of injury in the PT world or MOI. Was it contact? Was it non-contact? This makes it tough to decide, but nevertheless, a helpful factor to consider. Wow, I just said nevertheless, I’m sorry. But anyway, with something like this ACL injury, of course, that’s going to be very important because that’s going to help key in on. Was there a direct blow to the knee? And then how was that blow taken? Was it from the outside to the inside? Was it the inside to the outside? But contact can help us key in on, at least there was that direct trauma. And I will often say that if it’s a non-contact, you feel that pop and some of the things that we’re going to talk about, that I would almost suspect a little bit more of an ACL injury than when there’s contact included. Sometimes that could be a little bit more messy because there’s more force that has hit the knee compared to a non-contact injury. 

And so the other thing that leads me to this detective work is, did you feel or hear a pop when this knee mechanism of injury or this accident had occurred? And so my very first key in on an ACL tear is a very obvious pop. And I will say with my first ACL injury, I felt the pop, I heard the pop, I knew something was wrong with my knee as soon as it happened. My second one, not so much, it was a little bit more blurry. It wasn’t as obvious pop as the first one. But the first one, a pop is there. And a lot of times people will say they feel or hear that pop.

My first one was non-contact, cutting in an open space. I didn’t feel any pain. And it took a bit of time for that swelling to settle in. It was stiff a little bit. I felt some instability like my knee was going to give out. Then, yeah, that pain came in some. And then it was achy with an increase of pain and stiffness and swelling as time went on. And if anything, the best way I always describe it with people is that it felt awkward more than anything at first. Sure, there was some pain. But it was just the awkward nature of the knee moving with a non-contact injury. I felt that pop and shift in my knee like my knee glided a little bit, and then it came back to place and then I just fell. That was my whole incident. I know a lot of athletes I work with are varying degrees based on the sport, contact, and non-contact. Is it something that was skiing-related? Is it something that was, maybe you were just out recreationally doing something like hiking? There are varying degrees of the activity and how this happens. But this is my own experience and just pulling from other experiences of ACLers and how they feel. And especially clinically, like what am I looking at when I’m asking them questions and trying to make sure that we get as much detail as possible. 

In this first part, we talked about basically the story, the experience itself. And when I’m seeing this person, this is where I’m going to ask the details of that. That is called subjective history. And most importantly, we’re going to gain an understanding of that mechanism of injury. And then just the minutes and steps afterward of what happened to the knee and how they felt. Then that brings me to the next piece which is objective testing. Someone who is trained in this to be able to give you an idea of, okay, how can we objectively measure some things clinically to see, is this going to help us roll in or roll out some things?

One of the things typically we’ll see is a reduced range of motion, immediately someone’s extension starts to lag, and so they start to reduce in that range. They can’t hyperextend as much, typically because they’re swelling or there might be apprehension and there’s a little bit of inhibition in your quads. There’s pain that is playing into that, there’s swelling playing into that because of all the trauma to the joint and to the ACL graft and potentially other areas in the knee. Then you have that quad inhibition that I had talked about because of those pieces. The thing that I will test clinically is going to be a Lachman test, an anterior drawer, and a pivot shift test.

All those have some pretty solid specificity and sensitivity of being able to help us diagnose. With knowing that there is a level of error with anything we do as human beings and even with any testing that we do, whether it’s an MRI or even on the table. Of course, the MRI is going to have way better outcomes and it’s going to give us insight into the knee. But the important thing about testing that I do want to make sure we cover, and I covered this in the last episode as well, is some of these details. But with the clinical testing, since the knee can be guarded and the swelling has kicked in, it can be hard to know if that ACL is really torn after that, and we can get a lot of false positives. I mentioned how athletic trainers in games, if someone has a suspected knee injury, they will run on the field. They’ll ask if there is any sense of an ACL, maybe the person said there was a pop. They’ll try to test that knee as quickly as they can. And that will help give insight into if the ACL is torn because that swelling hasn’t set in yet. Therefore, we have less likelihood of any type of false positives or negatives. And this allows us to get a little bit more dialed in on the diagnosis. 

In most situations, like probably most of you listening, you don’t have access to an athletic trainer anytime you get injured so you have to make your best judgment. When we go to do any type of clinical testing later, if the knee is still swollen or painful, it can give us false positives. So that’s the thing we also have to be careful of when we do any of this clinical testing. And I’ve done this with fresh ACLs, and it can often be 50/50. That joint is full of fluid and they’re apprehensive. You go to try and do some of these tests and it’s just not as easy. And that’s where we need to let it calm down, and potentially assess it clinically again. 

But then at some point, an MRI is probably coming into the picture here. And so that’s going to lead me to the other big players to help determine this, the MRI. This is where they’re going to take an image of the knee. Typically, if you go to an orthopedics office, they will potentially do an X-ray. In most cases, they do. And so that’s just to see, okay, that’s like almost like the preliminary first thing they do, just to make sure there’s no bone breaks, anything else that they see. And then the next step, if the orthopedist does suspect an ACL tear or something else going on, especially if there’s been some sort of mechanism of injury, then they will schedule an MRI, just to see what is happening in the knee. And that’ll be something that’s typically separate. An MRI, in most cases, at least at the time of this podcast, that it takes roughly around 30 minutes to do. It seems long, at least. I remember those times, and there were times when I had to do 45 minutes. And it’s just a long time to sit still, but it’s something that we have to do. And it’s helpful to make sure we get a good, accurate diagnosis of if there is an ACL torn or if there’s anything else within the joint that we need to be aware of.

The other big player in this situation is instability. Instability is basically like the knee giving way or it shifts, especially when you’re taking a step at different levels. Let’s say something like a curb or coming off stairs or really can just be normal walking and it could be a weird foot placement or just the way that you’re moving. It might be a step here or there where it feels like the knee, if you will, shifts a little. It goes out of place, or it just feels like it loses stability and you have to catch yourself. That’s instability in a nutshell. This is usually an indicator of an ACL tear where the joint doesn’t have its ligaments to help provide its stability. And so that’s something that can play into this and help to give a fair bit of insight of, okay, maybe there is an ACL tear. 

Don’t forget the other concomitant injuries can throw this off though. Concomitant just means accompanying injuries that happen as the ACL is torn or as the injury happens. So that could be your MCL which is on the inside of your knee, LCL on the outside of the knee, the PCL which is pretty much right close to the ACL. It just helps with the posterior restraint of your tibia on your femur. You have your meniscus on the medial side and the lateral side. You have chondral or cartilage-based issues, you have bone bruising. It could be a bone fracture. There could be any type of other injuries related to the knee and inside the knee. You just have to be aware of these things that there could be things that throw this off a little bit. 

But if we’re looking at an ACL injury, just know everyone has different experiences. It’s going to initially come back to that mechanism of injury. And then it’s going to be a matter of what your subjective response is. Did you feel that pop? Did you have some sort of blow to the knee? Was it non-contact? Did your femur [?] rotate? Did your knee dive in? Are there positions that you were in where it looked like that knee caved to a normal ACL tear or that kind of video or picture that we typically see where that knee does cave in? That’s something we reference as knee valgus. 

Now, knee valgus can happen and the ACL might not tear. And it could be an MCL or a meniscus issue. There could be a whole slew of things. But that helps us to target in more on, okay, if there was that knee valgus position, then that gives us a little bit more of a filtered approach to know, okay, the ACL could potentially be at risk. Then clinically, it’s how you present and the testing to help confirm that hypothesis. MRI is what’s going to give you confirmation. So without it, no one can say with 100% certainty. And then even, as I said, the MRI can have some degree of error. But it has the most accuracy because it gives an image of the inside of the actual knee. Very rare that someone has a torn ACL on MRI and they get in there and it’s not torn. But it can happen and they might get in there and it could look partially torn or it could be something where it’s possibly been healing if there’s been a solid amount of time between the tear and the surgery.

There is an athlete, we just started working with remotely. She actually went in to have her ACL reconstructed because the MRI showed it. She had a pretty traumatic injury. And it turned out that her ACL was only partially torn. The orthopedic surgeon pivoted his plan. Instead of doing an ACL reconstruction, he actually did a repair where he just stitched it down. You never know, but this is not always the case. And probably in rare instances, just to give you guys a solid idea of this. But if you had those pieces of whenever this injury happened to you, it could have been something where you’re cutting, pivoting, or landing, or maybe you were on your skis or some sort of fixed device and you felt that pop, then that is something to suspect an ACL injury.

If you have instability with your knee whenever you’re walking or trying to navigate your daily life, that is potentially a suspicion of an ACL injury. And then of course, having some clinical testing to be able to help decide at the right time of seeing if there is a positive on a Lachman or anterior drawer or pivot shift, then can help suspect an ACL injury. Of course, we’ve got to piece all these things together in order to understand the story and what’s going on. Ultimately, an MRI is what’s going to be a very big piece to this to help confirm all of this clinical and subjective testing in order to understand what is going on. 

I hope that this helps the team. I have had a lot of people reach out who are like, I think I’ve torn my ACL, or maybe they had this false sense of it. And so I want to make sure we highlight some of the pieces that I see clinically. What we see in the research and what we see in medicine of this is what typically happens. And I also wanted to give you the practical rundown of what this looks like and the steps you need to put together and take in order to get to that confirmation of whether there is an ACL injury or maybe there’s not one. I hope you’re in that bucket. That is not one. But if you are that person who does have an ACL injury, just know that there is hope. Make sure you create a really solid team. Get a really solid game plan in place. Take it step by step. And of course, if you have any questions or need any help, you can always reach out to us. We would love to point you in the right direction. 

All right, team, that’s going to do it for today. Thank you all so much for listening. This is your host, Ravi Patel, signing off.