This article is a transcribed edited summary of a video Bob and Brad recorded in July of 2020. For the original video go to https://www.youtube.com/watch?v=PA1IgaJhx4o
Bob: How to tell if your knee pain is a meniscus or a ligament injury. This is an update on the topic, we did it once before. We’re going to try to improve upon it, make it better.
Brad: That’s right, and we will. With knee pain people are always wondering “Jeez I wonder, is it my meniscus?”
Bob: Well they say cartilage instead of meniscus.
Brad: There you go, cartilage, or is it that darn ACL or is it a ligament problem? So we’re going to show you that very clearly.
Bob: The ACL is a ligament by the way.
Brad: Yeah, exactly. But, there are three other ones that could be the problem and that’s what we’re going to show you. First of all, let’s take a look at Sam here.
Bob: Let’s do a little anatomy, just real quick.
Brad: So, all the muscles are removed, we’ve got the bone and we do have the tendon to the patella. We’re going to take that patella and the tendon, remove it, pull it out of the way. And then we’re going to open up the knee joint and we’re going to look at the meniscus first. So that’s this cartilage and it’s between the tibia and the femur. To me, they look like horseshoes.
Bob: Yeah, and they aren’t that pointed like this thing is.
Brad: It’s a little exaggerated, but the shape is pretty much there, it’s pretty similar to that. That is there for a cushion. It stabilizes the knee and offers some cushion. But now we’re going to jump to the ligaments. There are four ligaments that stabilize the knee, and we’ve got the ACL open, which is probably the ligament that you hear about in sports very often being injured and oftentimes torn or stretched. Surgery can replace it.
Brad: Then also right next to it there is the PCL. ACL means anterior cruciate ligament. PCL is the posterior cruciate ligament. It’s hard to see but it’s back there, that’s the PCL. And they work together, they stabilize the knee from moving forward and backward.
Bob: And cruciate means cross, the ligaments do cross.
Brad: Yes they do. This doesn’t show it that well but believe us. We’re also going to look at the MCL, the medial collateral ligament. That stabilizes your knee so it doesn’t go out. What would that be?
Bob: That would be valgus.
Brad: Knock-kneed would be the slang term. And then the LCL does the opposite, it keeps it from going this way. It would be that way if you were bowlegged. So that’s the anatomy and that’s the things that can get injured.
Brad: Now we’re going to talk about symptoms. And there is somewhat of a clear difference between symptoms. For example, if the cartilage (meniscus) gets torn, it can flip over. If you ever hear someone say their knee locks up and then eventually it unlocks and it feels pretty good again and they’re fine, then it happens again, that's what's happening. I had one patient going up and down steps, it would always lock up. She did it right in front of me on some stairs, she locked up and moved it around a bit, then it was fine. I said we’re done. I did a few other things but I said you have to go to the doctor. I felt confident it was a meniscus and it was. The next thing is usually a meniscus does not have any bruising or ecchymosis as we call it.
Bob: So if it’s a recent injury, you may get some bruising with the ligament but not as likely as with a meniscus.
Brad: Right, also with a meniscus, it can kind of happen without any particular reason over time, it just starts getting sore, and then some little thing might happen or maybe nothing, and then it’s just there with the locking.
Bob: I’m just going to add to this too, if it’s an acute injury, one that just happened, you may hear a pop with a ligament, where you probably wouldn’t hear one with a meniscus.
Brad: That’s right, very common with ACLs. People at football stadiums say “I heard it in the stands!” Meniscus typically is not going to have that. But also with ligaments, whether it’s ACL, MCL, or LCL, usually it’s a traumatic episode or incident. Oftentimes with sports but it doesn’t have to be.
Bob: Yeah, they don’t often tear over time. As you said, it can be an athletic event or a trauma from an accident.
Brad: A fall, etc. Ligaments will feel unstable, you don’t feel comfortable on uneven surfaces, that kind of thing.
Bob: And we should point this out too. It’s very common to often injure a ligament and meniscus together in an athletic event. The terrible triad.
Brad: That’s right. And oftentimes there’s going to be a surgery and they’ll address it all while they’re in there and take care of it. Now we’ve got to talk about some tests. So should we go through the meniscus first? Now these tests, there’s three of them we’re going to show you, you can do all by yourself and they’re relatively easy. I like to do them, I use them on my patients on a regular basis. The first one is the Thessaly test. Okay, so Bob’s going to do it and I’m going to do it. First of all, you do it on the leg that doesn’t hurt and see how it responds. And then the knee that does hurt, you’re going to stand on one leg, have the patient hang on to the wall, or you may have a stick or whatever. Bend the knee five degrees, which is very slight. Get it so it starts to bend, then rotate the body. We call this the disco dance.
Bob: Yeah and think about it. You’re grinding the joint together while you’re doing this.
Brad: And that’s kind of an overstatement hopefully. If it’s a healthy joint, it’s not going to be a problem. If you do have a meniscus or a cartilage tear, it may cause problems and cause pain. And then you’re going to go to 15 degrees, just a little bit further. Not a lot but just like what Bob did, repeat the test, looking for a problem or a tear in the cartilage in a different area. Now if it hurts it’s positive, if it doesn’t hurt, it’s not.
The next one, Childress or I call it the duck walk. So, feet are about shoulder width or a little wider. Keep your toes in a natural position, mine go out more, some people will be more straight. You’re going to bend the knees, about until you’re in this position, and so at that much flexion in the hips to the knees and you simply do the duck walk. You only take about four, five, or six steps. If that creates pain in the knees, that’s a positive sign.
Brad: Now with these meniscus tests, we’re going through three signs or three tests right there that you can do at home. I’ve got one more to show you. It’s called the Payers test and this one, you lay down, and you can do it on the floor. The right knee is the knee that’s suspected of an injury, put the right foot on the side of the left knee, and let that leg drop down, just by gravity. That stretches the knee and if that also creates pain it's a positive sign. If all three of those tests created pain, it’s a pretty good chance you have a meniscus injury, not 100% but fairly good.
Bob: Or cartilage, or as some patients call it, cartridge.
Brad: Exactly. I’m going to show you two tests. These are two tests that you probably are not going to do at home. This is what a therapist or a physician may do with you, just so you know. This is called the Apley’s Compression Test. The left knee is the one in question. I put a towel roll or a nice cushion under the leg. That’s just a little more comfortable for the patient. And what I do is I put pressure down and rotate and then extend the leg like this with pressure, with internal rotation and external rotation. That will become uncomfortable and the patient will complain of pain. That would then be positive.
Brad: The next one is McMurray’s test. With this one, therapists or doctors will rotate the leg. And I have to be honest with you, I don’t use this one very much and I never have since I learned it because I have a hard time with it. I have seen some surgeons do it on a regular basis. They are really good at it. I’ve had really good luck with my other tests so I feel confident.
Bob: What I do when I do this one is I actually put my hands right on the joint. Then you can feel clicking.
Brad: Okay so you’re feeling around that joint line. To know where the joint line is takes practice. Most people cannot just say “Oh there it is.” I remember learning that initially.
Bob: So it’s kind of a tough test to do, he’s turning it and grinding it.
Brad: Now let’s look at the ACL, MCL, PCL, and LCL tests. You’ll need to be a therapist or doctor to do these. It takes a bit to learn it. I’m going to show you one of them for the ACL.
Bob: Actually a lot of times you’ll do it on the good leg, the non-involved leg first, just to see what normal feels like. And then you test it on the involved leg.
Brad: Right so if the right leg is in question, I’m going to grab under the knee, and this is called the Anterior Drawer Test. I’m going to pull toward me, and that’s going to test the ACL. My thumbs right here are on the joint line and you can actually feel movement. I can feel Bob’s tibia come towards me as I pull on it.
Bob: If it’s torn it’s going to move more on this one than it would on the other one.
Brad: Exactly. And you can feel it. And there’s not always pain associated with it either, like you may think there is. Then the PCL, which I’ve never worked with anyone with a torn PCL yet.
Bob: I haven’t either honestly Brad.
Brad: Yeah, but it does happen. Not very often. You simply push toward the patient and compare the good one to the bad one and you can palpate the joint line to see if there’s more mobility.
Brad: Now the LCL and the MCL, usually I’d take you to the side of the bed. I’m going to do his LCL first. Can you just relax Bob? And we do a little bend on the knee and I’m going to push away from me with the hand by his knee and push toward me with the hand by his ankle. We’re stressing that outer ligament. You're pretty tight Bob. I don’t feel any laxity there.
Bob: I have good ligaments. I've never had any trouble, they always look good.
Brad: Now, normally, I’ll do the MCL test facing the patient. I don’t know if the MCL is injured more than the LCL or not.
Bob: I think it is often injured with other ones, like with the ACL.
Brad: Along with possibly the meniscus. Normally I stand in front but then you can’t see what I’m doing. I’m going to do it here, but I’m going to hold on to the outside of the knee and slightly flex the knee to five degrees. Then I’m going to push away from me at the ankle. So I’m pushing his leg out that way and then I can assess the integrity of that ligament on the medial side. Again, done by the therapist or doctor. And you’ll know what they’re testing for.
Bob: But you can see that they’re just putting stress on the ligaments and if they’re torn or stretched, there’s going to be a lot more movement in the injured one than the non-injured one. And that’s the problem, the knee gets sloppy then. Over time if you don’t repair it, it can put more stress on the cartilage and wear it out.
Brad: Yeah, premature arthritis, it could lead to other issues there.
Bob: I have two friends that had ACL tears and didn’t repair them. One was a physical therapist and he’s now had a knee replacement. And the other one, he’s a friend, and he’s had a knee replacement. So, you get to our age, it starts to show.
Brad: With a knee replacement, I think they take the ACL out and it’s nonexistent, so they didn’t have to do that on that part of the surgery. I hope they gave them a discount.
Bob: That’s right, I doubt it. There are no discounts in this world.
Brad: Alright, very good, good luck with your knee pain assessment.
Bob: Yup, thanks for watching.
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