147. MCL Injuries: Anatomy, Causes, and Treatments

In this episode of the PT Snacks podcast, host Kasey delves into medial collateral ligament (MCL) injuries. Listeners will gain insights into the anatomy of the MCL, common causes of injury, and who is most susceptible. The episode also covers how to assess and diagnose MCL injuries using specific tests and medical imaging, as well as treatment options and prognosis for different injury grades. Suitable for physical therapists and students, this episode provides essential knowledge to enhance their understanding of knee injuries and effective treatment strategies.

00:00 Introduction to MCL Injuries

01:55 Understanding MCL Anatomy

03:54 Common Causes and Risk Factors

04:55 Diagnosis and Assessment Techniques

07:33 Treatment and Prognosis

08:55 Conclusion and Additional Resources

Transcript

0:27

You know what I realized is I don't really talk about the knee all that much on this show. So today we're gonna talk about MCL injuries and dive right into it. Hey everyone. Welcome to PT Snacks podcast. This is Kasey, your host, and if you're tuning in for the very first time, first of all, welcome. But what you need to know is that this podcast is meant for physical therapists and physical therapist students who are looking to grow your fundamentals and bite-size segments of time. Now, today we're gonna be diving into MCL injuries or medial collateral ligament injuries, and essentially talking about more how they happen who this happens to. We are definitely gonna dive into anatomy.'cause I think that's important for understanding the previous things I mentioned. And how do we test, assess, and get them back to what they wanna do with these types of injuries. Before we dive in, if you've listened to at least three episodes of this show and you found it to be helpful, if you wouldn't mind leaving a review wherever you listen to this, that would be amazing.'Cause those really do help make a difference. And if you already have done so, thank you so much. I really appreciate you. Now for today, talking about media collateral ligament injuries, what we need to understand is that this ligament is a key stabilizer in the knee, especially. With valgus force and can often get injured when there is some sort of force pushing the knee inward in a valgus force, especially during sports or some sort of trauma, it's actually the most common knee ligament injury, especially in contact sports. And aside from that, even ligament injuries in general make up 40% of all knee injuries, that is reported. There's also likely many low grade MCL injuries that go unreported. So really important for us to have a good understanding of how this happens and what we do about it. Now, diving into anatomy, the medial collateral ligament is a flat band of connective tissue that runs from the medial epicondyle of the femur to the medial condyle of the tibia. It's about eight to 10 centimeters in length, like that's big. There are different portions of the band, so we have our superficial and our deep portion. Our superficial originates proximal from post the posterior aspect of the medial femoral epicondyle, and then it attaches distally to the medial condyle of the tibia, about five to seven centimeters below the joint line, and it's near the level of but posterior to the pes anserines insertion. Now the deep portion, that is a major secondary strain as well to anterior translation of the tibia and a minor static stabilization agent against the valgus stress. So it's a thickening of the medial joint capsule, some people think it is, and it's also divided into meniscus, femoral and meniscal tibial components. So meniscus femoral, we have our ligaments of Humphrey and Berg and then meniscal. Tibial. We have our coronary ligament components. If we're taking a step back and we're looking at the medial knee, we can split it up into three layers for capsule, ligamentous complex, so superficial midal and deep layer, our superficial layer. For the capsule ligament is complex. I'm not just talking about the MCL. Here we have the Sartorious and investing fascia forms part of the patella, Retin ulu In the middle layer, it includes a semi semimembranosus, but we also have some of the superficial MCL medial patella femoral ligament, and posterior oblique ligament. And then in our deepest layer, we have our deep MCL posterior medial capsule and meniscal tibial ligament. So these help provide val stability to the knee joint and helps to control knee rotation. Alongside the deep MCL and posterior oblique liga. Now who gets this? Who does this happen to? One reason I don't want to try skiing, this is a me thing, is 60% of skiing knee injuries involve the MCL. But we also, we see from other things that I am currently doing, so abrupt, turning, cutting, and twisting, especially when the foot's planted and the knee is slightly flexed. It could be sports like soccer, basketball it could be from direct blows to the lateral knee. Valgus stress most common in football, hockey, skiing. And it can be isolated as an injury or it can occur with other injuries. So we have our unhappy try it which is when the M-C-L-A-C-L and medial meniscus are all injured together. The superficial portion is more likely to get injured by minor trauma, whereas if someone has a higher energy impact, it can disrupt both superficial and deep layers. And the femoral insertion where the MCL attaches to the thigh bone is the most common site of injury. Now if someone's coming into our clinic or maybe we're assessing them somewhere else, how do we catch this? So generally that person's probably gonna complain of medial knee pain. So it could be acute. Maybe they had an incident or trauma that resulted in pain or swelling, potentially a pop. Or maybe they have difficulty walking and have noted some knee instability, like it feels like it's gonna give out. They may have effusion localized around the MCL which it's not really generalized, like other intraarticular injuries. In terms of swelling. And then in our exam, we wanna look at palpating the full length of the MCL. That's why anatomy's important. Some mid substance tears can cause tenderness at the medial joint length, so it can be confused as the medial meniscus. We wanna look at a valgus stress test, so that's where the patient is supine with their hip abducted on the affected side. So the leg is unsupported off the table, and you'll start off with their knee in 30 degrees flexion. And you're comparing laxity to the other side, as well as laxity at 30 degrees compared to zero degree on the same side. Now, the PCL and the posterior joint capsule can also help with knee stability in zero degrees. If it's seeming to be positive at 30 degrees, we still wanna check out zero to compare, but also if it's positive in both. We might have more than just an MCL injury going on. Now with these tests, they're divided into different grades. So we have grade one, grade two, grade three. Grade one is they have pain along the MCL with valgus stress, but little to no gapping, maybe three to five millimeters of laxity. Grade two, there's some opening of the joint, but a firm endpoint, five to 10 millimeters of laxity. And then grade three, the most severe significant joint opening. And no endpoint more than 10 millimeters laxity. Yikes. This may take some practice to assess, so it is definitely important to compare to the other side. To see what that patient's normal is. Now we do want to also test for potentially ACL injuries or PCL or even medial meniscal injuries for concurrent injuries and not just write it off to MCL because we know that it can happen with other things too. And then other tests as well. They may get imaging to see if they have any other OC cold fractures or avulsion fractures. An MRI is gonna be the gold standard for the diagnosis, but if your clinic has an ultrasound, that can also be effective too. And then in terms of treatment, grade one and two are generally gonna be treated more conservatively in this. They have an associated injury that makes the overall more severe. But we do find that early joint motion tends to have a better outcome over immobilized joints to basically help to create better ligament healing, better quality ligament healing, weight bearing. Is encouraged when appropriate with weight-bearing tolerance. But we wanna also factor in things like pain with weight-bearing, how their quad and hamstring activation is, what their gait quality is all that sort of stuff. And then in terms of prognosis, generally grade one and two, have a good prognosis with an earlier return to sport or return to work. Now, grade three I haven't mentioned on purpose. And that's because if it is occurring in isolation, it's probably gonna be managed pretty similarly, although they may progress slightly slower. The MCL has a pretty good blood supply for healing, whether proximal or distal tear, but the risk of associated ligament injury is 78% with the ACL being the associated injury 95% of the time. And then recurrence of the MCL injury is 23%. So it is possible for these grades to be managed surgically. Essentially, what you should have gotten from this was an anatomy review. Understanding of what the MCL does and how it is traumatized and how it is injured, and then how we test for it. If you have any questions at all, feel free to reach out at PTs Snacks podcast@gmail.com. But otherwise, if you are in need of more c use maybe you're studying for a specialty exam, like the OCS or SCS med Bridge is actually offering listeners over a hundred dollars off. Your subscription, which for them includes tons of courses, online webinars, specialty exam prep. So they have practice tests that you can run through and get some screen time or get used to some more screen time while you're testing for the actual real thing. But also they even have a home exercise program builder. Where you can put together exercises for your patient, write in, rep sets, all that kind of stuff. And you can either print it off for them or you can email it to your patient and they are able to go online and watch videos of these exercises. So pretty cool stuff. Check out the show notes for the promo code. It's PT Snacks podcast. And then students, you get an even better discount with your promo code. So definitely check that out below. But other than that, make sure you're following the show so you don't miss any upcoming. Upcoming shows and I hope you guys have a great rest of your day.