Hey everyone, thanks for having me today. I'm going to be talking about lateral ankle instability. My name is Jess Mullins. I'm at the University of South Alabama in Mobile. I want to thank Dr. Tanner Cox, one of my residents, for helping me put together this and help me with the references. As far as disclosures go, I am a consultant for Arthrex, but we won't be talking about any specific products today. Making more generalizations about treatment of ankle instability. I also consult for Crossroads, but that will not conflict with this talk. Dr. Cox has no disclosures for this talk. So what are we going to talk about today? We're going to mostly be talking about lateral ligamentous instability. We're going to touch on the anatomy, look at how these things happen, what how the things we use to diagnose it, such as MRIs, ultrasound, sometimes x-rays, as well as look at treatment and how that has progressed over time. We're not going to talk much about syndesmosis instability or deltoid instability, though we will kind of touch on a couple of those things at the end and how they pertain to lateral ligament instability. So, you know, lateral lower ankle sprains are one of the most common injuries that we see, and in the U.S. alone, about two million of them are going to happen each year. The lateral ankle sprains account for about 85% of all the ankle sprains, and when you look at all athletic injuries, about one-third of them are going to be ankle sprains. Different things factor into this, like we know ligamentous laxity and testing our patients with a Biden score, taking a look at their hind foot alignment and checking to see if they have cavo varus, other things like previous injuries, what kind of athletics they participate in, and previous histories of trauma. So it's very important that we understand the lateral ligamentous complex and the anatomy and how this pertains to the injury and how we treat them. We need to understand that the ATFL is actually a weak ligament in relation to the calcaneofibular ligament, but it's important to kind of understand what this anatomy is as far as examining these patients. A lot of times they'll come into your clinic and be incredibly swollen, but it's one of the areas of the ankle that we can examine closely and come to a diagnosis just from palpation alone. This study by Klan will come back to in the later on in the talk, but it's very important with understanding where these ligaments insert, where they originate, and this particular study that was looking at the footprints gives us our best detail on how we reconstruct these ligaments in the long run. It's also important to understand about the posterior talofibular ligaments, one of the more commonly disregarded ligaments of the lateral ankle complex, but that's because we don't see the same kind of injuries with those. With the ATFL you can have different bands. Sometimes it's not just one single band, but it can be trifurcate in some patients, but most commonly it's two bands. It originates on the distal anterior fibula and inserts on the body of the talus, just anterior to the articular facet, and then you have your calcaneofibular ligament, which is actually stronger than the ATFL, and it originates just below the ATFL and inserts posterior to the calcaneotubercle. The other things that we need to take into account with lateral ankle instability are the inferior extensor retinaculum, which the lateral lies more superficial to the extensor tendons, and then you also have your subtalar stabilizers with your lateral talocalcaneal ligament as well as the cervical ligament. When we look again at the anatomy and where these insert, I think this study is very interesting. It was another study done by Clan that was using steel balls to place on the origin insertions of the ligaments and taking a look at how those translate to x-rays, and as you can see, most distal fibular fractures that we are seeing kind of insert, or the distal fibular fractures actually occur just above the line of where these ligaments insert, and so it's important to kind of take that into account when you see fractures. So the joint stabilizing function of the ligaments is most critical when the foot is actually not impacting the ground. So when at first you'll see a lot of these injuries, like you see this video here, is right when the foot touches the ground, when the toes make impact with the ground, that's when the ligaments are usually at its weakest and are required to do the most work, and so the bony configuration of the mortise actually provides the stability in a loaded ankle. So how we tension these ligaments at the time of surgery and how we understand them is important. So in dorsiflexion of the ankle, the ATFL is loose and the CFL is taut. The PTFL is actually maximally stressed in the dorsiflex position, but then as you go into a more plantarflex position, you have the ATFL being taut and the CFL being loose. And the ATFL, like we talked about before, has the lowest load to failure, and so it's the most commonly torn ligament of the ankle complex. And then the ATFL also undergoes the greatest deformation prior to its failure. So in the dorsiflex ankle, the PTFL does have restriction. It helps restrict external rotation and dorsiflexion along with the deltoid, and it does resist adduction if the CFL is ruptured. And then in the neutral ankle, that kind of pertains to a Taylor tilt test, the CFL is preventing adduction of the hind foot. And then in a plantarflexed ankle, the CFL does contribute some, but it's mostly the ATFL that prevents that adduction. So two types of instability that are important to to take a look at is the functional instability, right? So that's just the feeling that your ankle is going to give way. When you examine these patients, they may not have any ligamentous instability. Their interior drawer may not be positive, their Taylor tilt might not be positive, but they always come in and say, I feel like my ankle's giving way all the time. And then you have the mechanical, which is more according to your physical exam, increased range of motion beyond physiologic ranges. ATFL is the most common, then both ligaments, and then the CFL alone. Mid-substance tears are more common than seeing the avulsion injuries, and you're more likely to see fibular avulsion fractures, though Taylor avulsion fractures are possible with these injuries. It's important to recognize other types of injuries like peroneal tendon tears, osteochondral lesions, medial deltoid ligamentous instability, as well as syndesmotic injuries, and as well as fifth metatarsal avulsion fractures. You may also see a ligament avulsion at the calcaneo-cuboid joint, so it's important to keep a high suspicion for these injuries when you're examining the patient. The other thing we see commonly with so-called ankle sprains is a snowboarder's fracture, right, is a fracture of the lateral process of the talus that is even easy to misc on routine x-rays of the ankle, so keeping a high suspicion for these injuries as well. So when we see these patients, how are we examining them, what is the history? Most of them report some type of rolling of the ankle, but if you ask them to say, well, what happened? Was your foot positioned in supination? Was it externally rotating at the same time? Most of these people can't tell you exactly how it happened, they just know they rolled their ankle. Some of them feel a pop, and then it's important to understand, were they able to walk immediately, or when they went to the ER later, were they able to walk then? When we look at MRI studies, we actually find that it's really good at finding the grade 3 injuries, but only about 25% accurate for grade 2 injuries, so it's important to kind of get a good history and physical on these, and again, like we talked about, is that the associated injuries are often overlooked, is that we just talk about the ankle sprain, but we don't really sometimes examine the peroneal tendons as close as we should, as well as really looking at our x-rays to find out if there's any OCDs that could be displaced. So when we examine them, the two most common tests we see with it are the anterior jaw and the tailored tilt. The pictures on the right are from Mann's book, and that is kind of a reverse anterior jaw, where you put the foot down on the bed, and you're actually given a posterior translation to the tibia in order to see that suction sign, which is seen in picture B, and that can indicate lateral ligament instability. And then your tailored tilt in a neutral ankle position could sometimes demonstrate relaxation, though I think a tailored tilt test is a little bit harder to see versus our anterior jaw. So the question always becomes in ERs is do you x-ray these patients? I think more commonly in orthopedic offices, we are getting x-rays on these patients because we do know the associated injuries that can happen with them, but you do have the Ottawa criteria that takes into account tenderness along the malleolus as well as, you know, tenderness along the fifth metatarsal base, and do they have more proximal tenderness, and how does this affect the way we get x-rays. But if we follow these criterias to a very strict degree, a lot of times we can miss some of these associated injuries that happen that can lead to more complex issues. So when I do get x-rays, I do get an AP mortise lateral and a weight bearing if possible. I don't routinely get stress views on these patients as I feel like they guard most of the time. It's difficult to get a good exam on them and it just increases radiation to the patient, and I think a lot of your decision with treatment is based on what they've done, based on your physical exam, their history, those kind of things play a bigger importance to me as far as deciding when to get stress views. If you want more definitive diagnosis, MRI is a scan to go, and it is replaced CT scans, arthrography, tonography, as far as looking at these things. In the past they used tonography to look at CFL tears and determine if there was a rupture happening from this, but the MRI can show a lot of detail and all the associated injuries at the same time. MRI is not something I routinely get on my patients with an ankle sprain. We treat these patients conservatively as we'll see, but an MRI is used if patients aren't returning back to their activities as you expect them to. Ultrasound is becoming a bigger part of how we diagnose these injuries. Using a dynamic stress ultrasound is comparable to stress radiographs without the radiation, and now they actually have automated measurement systems that have taken away the need to manually measure the amount of laxity that we're seeing. So I think you'll see the ultrasound being used more commonly to diagnose these from actually having objective measurements. So how we treat these and the prognosis of them is usually we want these people to return back as they as they're able to, as when they can the earliest they can go back we want them to. But you know ankle sprains aren't benign injuries. Studies show that 32% of patients can have chronic complaints of pain, swelling, recurrent sprains. Up to 72% have some type of functional impairment when trying to get back to the desired activity level. And then even up to six months patients can have up to 40% of ankle dysfunction as well. So when we classify them, I don't use the classification system that strictly. I think for me a grade three sprain is the patient who has a lot of difficulty even placing a little bit of weight down on their ankle. I think the grade one sprains is things that we've all had is rolled our ankle on a curb it hurts for a little while but we're pretty much doing everything we have. And grade two is somewhere in the middle. Clanton when he wrote his chapter in man's book kind of classified it between type one stable and type two unstable and then use stress radiographs to kind of go more into the types and you know different groupings as far as young athletes and older individuals that are just going to get conservative treatment. So that kind of led to treatment recommendations but I think most of us aren't using this a lot of times to guide our treatment. As far as treatment with lateral ankle sprains, non-surgical is the mainstay of management even with athletes. They haven't shown that grade three sprains are any more likely to to undergo operative intervention versus grade one sprains. A lot of this depends on what they're doing and how they're taking care of their ankle following the injury. Evidence favors the non-surgical approach even with acute ankle sprains and to reserve the surgical repair for those with persistent symptoms. And you know the good thing about no matter what you do 75 to 100 percent of these patients are going to do good regardless of how you treat them. So as far as functional treatment we want to rest, ice, compress, elevate. We want to get some type of a mobilization device on them usually just to give them some support while they're healing. And for me that that ranges from even placing them into a cast if they have severe swelling, can't place any weight down on it, they don't think they'll do good in a boot walker. I'll even shut them down in a cast for a week and bring him back for a repeat exam in a week and then transition them to a boot. I want them to get out of that boot as soon as possible because we know the side effects of putting people in a boot or putting them in a cast for too long and we want to get these patients moving so that they can get back to their activity level. As far as looking at lace-up braces, taping, the important thing is to get the foot into dorsiflexion because that's the position that you want the ATFL to be in as far as it heals. You don't want these patients to be in in plantar flexion and inversion like they want to hold their foot because the ligament can heal in a stretched out position. But the overall goal is to progress weight-bearing and get off the crutches as soon as possible. As far as the functional treatment, peroneal tendon strengthening, Achilles stretching, I think the most important thing is proprioceptive training and really working on the peroneal tendons and the small muscle contractions around the ankle will help give stability to it. I think it's important for athletes to wear some type of ankle support whether it be a brace or taping for the remainder of the season just to keep stability to their ankle. As far as surgical treatment, this to me is reserved for patients who aren't improving. As people have hit a plateau, they cannot return back to their activities. Those patients who can't even get out of a boot after six to eight weeks of treatment, I don't think necessarily six months of non-surgical treatment is best for some of these athletes as they have significant dysfunction and if they're not returning back in a predictable amount of time, then we need to pay attention to these improvements and decide how we're going to treat them in the long run. There's no advantage of acute surgical management over non-surgical management and that has kind of led me, a lot of times patients will come in with MRIs, their parents will come in with MRIs showing you have an ATFL tear. Well, I found that some of these patients, if they were to be treated surgically, all the tissues are very friable when you go in for surgical repair and reconstruction. I think allowing that time for things to consolidate, get the ankle moving first before proceeding forward with any type of surgical treatment because we've seen that no matter how you treat them, a lot of these patients are going to improve without any type of surgery. With the surgical group, you'll see higher rates of complications, longer recovery, more stiffness. You know, professional athletes, that becomes a point of debate. I think a lot of that depends on timing of injury in relation to the time of their season, when we're trying to get them back, how, you know, based on MRI, how severe their injury was, associated injuries, and all those things to decide. Just have a conversation between you, the patient, of how you're going to proceed forward with their injury. As far as the different types of treatments and surgery, we have the Brostrom, the modified Brostrom, the Carlson, which has sometimes also been known as a modified Brostrom Gould that incorporates inferior extensor retinaculum in order to get more strength to the repair. The Brostrom was originally just a direct repair of the attenuated ligaments using the native tissue, and this was considered the first-line surgical treatment option. The modified Brostrom was more using bone blocks to reattach the ligaments and passage of sutures through drill holes of the fibula in order to obtain the repair. And again, the Carlson was also known as the modified Brostrom Gould. Going back to clay and study, this is what I use and how I determine where I'm putting these ligaments, where I'm putting my anchors, or making my repairs, or if I am doing a reconstruction, knowing where I'm inserting the ATFL on the talus as well as the fibula and the calcaneal fibular ligament on the fibula and the calcaneus. So I think this study is very important with knowing the approximate insertion of these ligaments. And then kind of understanding how we repair them. Why do some people use suture anchors? Why do people use just direct repair with pants over vest? This study by Waldrop looked at 24 cadaver ankles. They looked at just the normal ligament. They looked at the Brostrom. And then they looked at placing anchors in the talus and fibula. And what they found was that the anchors and suture repair were all strong, but they were all weaker than the native ligament. So it kind of leads us to find out how can we make this better. You know, there have been satisfactory clinical results in treating chronic instability with the standard Brostrom. But in up to a fourth of patients, you're still seeing chronic swelling, ankle pain, joint stiffness, and recurrent sprains. So how can we make it stronger? Well, this study by Vins in 2014 looked at 18 cadavers, three groups, and intact ATFL using suture tape augmentation or in a Brostrom with suture tape. And what they found was that using a suture tape resulted in comparable or greater strength than the native ATFL. We know the ATFL is a weak ligament to begin with, so we need to find ways to keep it strong to allow these athletes and patients to return back to quick range of motion, strengthening of their ankles so they can return back to the activities that they want. Then come things like arthroscopic repair of the ATFL. This becomes an attractive option as it's less invasive. It's been shown to reduce post-operative pain and enable a faster recovery, more related to surgical incisions in my opinion. This study from Giza in FAI in 2015 looked at 20 cadaver ankles and they looked at different suture anchor constructs and augmentation with a knotless anchor. And what they found was using one versus two anchors made no difference in its strength to failure. Now, as you're looking in chronic instability in the face of maybe previous surgical intervention, we need to look at how you're going to reconstruct some of these. Well, classically they did non-anatomic repairs. I think the thing you see the most was the Christman Snook and they sacrificed the peroneal tendon in order to reroute it. But this created non-anatomic forces across the ankle and subtalar joint which led to concern for future degeneration. So I think most of us have gone to more anatomic reconstruction and this study by Klan looked at six controls, six reconstruction. What they found was that reconstructing with a semi-tendinosis tendon resulted in just as strong an ATFL as compared to the native ATFL. And then looking at this, you know, looking at this study though shows that even with doing the reconstructions, these patients can still have severe limitations. Up to a fifth of them had discomfort and swelling after healing. Nearly more than a tenth of them had decreased range of motion and some patients had soft tissue irritation from the grafts. So this study, another study done by Klan, looked at 86 patients. 61 of them had repair of just a brostrom and then 25 went on to reconstruction. And what they found that after two years there was no difference in activity levels or patient satisfaction. It's important to kind of know what failure means in patients as well is that some of these patients will have recurrent injuries and so is that you know in 40% of patients recurrent instability was their definition of failure. Rerupture in 19 patients and about 57% of those had some type of brostrom gould technique when repairing it. Like I told you at the beginning I was just going to touch on the syndesmosis as these things can be associated injuries and it's important that MRI doesn't always pick up on these injuries. And what this study showed us was that patients were underwent an arthroscopy before their lateral ligament reconstruction and in those patients that had greater than four millimeters of widening of the syndesmosis on arthroscopy, they had a longer return to work or recreational sports. They had significantly higher instability rates and lower proportion of return to their sport. As far as return to sport goes it's important that we were able to educate these patients on when they're going to be able to return. So this study looking at 66% football players, 21% rugby, 83% had just isolated ATFL CFL ligament injury, 17% of them had more associated injuries including syndesmosis OCD and deltoid. They found that there was a significant difference in return to sport for just an isolated lateral ligament with about 68 on average days versus having more associated injuries increase that up to two weeks longer. When you look at those specific injuries it could be a week or longer for a deltoid up to a week longer for syndesmosis and a significantly longer return to play for an OCD lesion with greater than a month. So it's important to use these data to educate your athletes and what they can expect moving forward. Attached are my references that I've used for this talk and I thank you for let me talk to you all about lateral ligament instability and I hope you have a great day.

lateral ankle instability

University of South Alabama

Jess Mullins

diagnostic methods

treatment options

ankle sprains