High Ankle Sprain

A “simple ankle sprain” can be the most expensive diagnosis in sports medicine when it’s wrong. We’re unpacking a case that looks ordinary at first glance: a 16-year-old wrestler who can still walk, has normal-looking initial X-rays, and yet can’t return to the mat because the pain is higher than the usual sprain spot. That detail changes everything, pushing us toward a high ankle sprain and a syndesmotic injury rather than a routine lateral ligament strain. 

We talk through the exact mechanism that should set off alarms, forced external rotation often paired with dorsiflexion and sometimes eversion. From there, we map the anatomy in plain language: the lateral ligaments that drive most inversion sprains versus the anterior inferior tibiofibular ligament and the wider syndesmosis complex that stabilises the distal tibia and fibula. We also share the exam findings that matter most, including tenderness at the distal tibiofibular junction and pain reproduced with dorsiflexion plus external rotation. 

On the imaging side, we cover the practical radiology checks clinicians use every day, including tibiofibular overlap, tibiofibular clear space, and medial clear space on AP and mortise views. We explain why gravity stress views can help but also why MRI is often the decision-maker when X-rays don’t match the story. Finally, we walk through treatment and recovery: conservative care with a CAM boot and delayed weight bearing versus surgical stabilisation such as tightrope fixation for athletes chasing a faster, more reliable return to sport, plus what rehab progression typically looks like. 

If you found this helpful, subscribe, share it with a teammate or clinician, and leave a review so more athletes and providers can spot a high ankle sprain before it costs a season.

Transcript

Welcome And Case Overview

SPEAKER_00 0:00

Hello, everyone. Welcome back to the podcast. My name's Chuck Dowell. I will be the host of today's podcast. Today we're going to do another case description. I've seen a couple of these come into the clinic recently, so I thought this would be an interesting case to review or go over. Again, this will be a case review. So the x-rays and imaging that I kind of discussed during the podcast will be on our YouTube channel. So if you want to go over to the YouTube channel, you can see all the images, the MRIs, some images kind of discussing the anatomy itself as well. So for this gentleman, this is a 16-year-old who came in and saw me at the orthopedic urgent care. He says he was wrestling a week earlier in Utah. His foot got caught on the mat kind of under other, excuse me, under the other wrestler or the opponent, and he had kind of this forced external rotation of his ankle. And he showed me this with some pictures and videos. Again, I think a lot of patients do come in with videos, and the videos can be quite helpful to help to distinguish the mechanism of injury. Where for me, if I can get a good establishment of the mechanism of injury, oftentimes I can think about the kinesthetics of the joint, what stresses that joint went through, and potentially what that would show me would be injured.

Classic Low Ankle Sprain Anatomy

SPEAKER_00 1:22

Umnytime somebody comes in and they describe not this traditional ankle sprain, so you can see the image on the um again YouTube channel right now. So when we talk about the ankle itself, most traditional ankle sprains, there's an inversion of the ankle. So the ankle rolls inside, and typically this injures the ligaments on the outside part of the ankle. So the anterior tibial fibular ligament, it's typically the tightest, and usually the one that you know gets injured first, especially if it's a little bit of a plar flexion and an inversion type activity. And then typically the calcaneary fibular ligament will get injured second. Now, sometimes this can be injured in isolation with just a straight inversion injury with no plantar flexion as well. And then usually if those two are injured or torn, it can then possibly injure the posterior tibiofibular ligament. But typically the ATFL and the CFL ligaments are the ones that get injured the most and are first. And so usually when you're doing a physical exam, they'll have some tendinus here in this anterior ankle area. When we're looking at and talking about the ankle anatomy itself, you can see again on the depiction here the anatomy of all the ligaments and kind of tendinous attachments throughout the ankle. Again, most commonly injured is this anterior talofibular ligament, which connects from that anterior distal aspect of the fibula to the anterior lateral aspect of the talus. Calcanear fibular ligament is then usually secondarily injured as well. And then the posterior talofibular ligament can be injured. But again, sometimes patients can have injuries to this anterior tibial fibular ligament, which sits a little bit higher and connects that anterior aspect of the fibula to that distal tibia. And posterior to that is a posterior tibiofibular ligament as well.

What The Syndesmosis Really Means

SPEAKER_00 3:17

We often refer to this as the syndismosis, but this is actually the ligamentous complex connecting those distal and or that distal joint. The syndesmosis extends a little bit higher to this itself. So when some people refer to the syndosmosis itself, they will refer to the entire complex of the posterior anterior tibial fibular ligament and this interosseous membrane, especially this distal aspect of the interosseous membrane that connects the tibia and the fibula all the way up through the ankle. Oftentimes there'll be kind of the syndismosis is all encompanying with all of this. Sometimes just this inferior aspect of the interosseous membrane can be referred to as a syndismosis as well. But again, when we talk about high ankle sprains, syndismotic injuries is typically what we're directly referring to and discussing.

Patient Story And Key Exam Signs

SPEAKER_00 4:09

So this gentleman, again, 16-year-old, came in. He was ambulating on it. He had tried to treat it conservatively for approximately a week with, you know, the typical elevation ice, anti-inflammatory meds. He had not wrestled and/or tried to wrestle one time since then, but unfortunately was not able to wrestle due to the pain within the ankle. He came in, we got x-rays, including five use of the foot and ankle. Um, our typical x-rays that we get. Uh you could see his x-rays here on the screen. So x-rays in themselves did not show any significant um changes to the ankle itself. No obvious fractures that were seen when looking through the x-rays themselves. On his physical exam, though, this is where you know I think most of the important information was gained. He had quite a bit of tenderness, but his tenderness was not in this traditional tenderness we see, distal where that uh anterior talofibul ligament tenderness was at. His was up here in that anterior tibiofibular ligament uh area. So, again, when we're discussing and look at the anatomy, um his tenderness was up in this area where that junction of that distal tibia and fibula was at. Um he did have some mild tenderness around these lateral ligamentous structures, but majority of his pain was up into this area. He also had increasing pain uh with dorsiflexion of his ankle, um, as well as dorsiflexion and external rotation, which oftentimes can stress this joint itself. So, again, the mechanism of injury for these high ankle sprains is usually this uh foot rotates outward, so this forced external rotation with internal rotation of the tibia. Um, and so usually this is with the ankle in a little bit of a dorsi-flexed position. Uh, they can have eversion of the ankle as well, which is the opposite of inversion, and that would push that that talus against the distal fibula and affect more of this anterior tibiofibular ligament or syndismotic area. So anybody that comes in and has a mechanism consistent with this, I always worry about these high ankle sprains and tend to spend more time with my palpation and evaluation regarding this. The patient also did have some tenderness over his deltoid ligament, uh, which I think uh andor typically often corresponds to a high ankle sprain type injury as well, anytime this deltoid ligament is injured, and that may have meant he had more of an eversion type injury than just direct an external rotation type injury.

X-Ray Clues For High Sprains

SPEAKER_00 6:54

When we talk about what to look for on the x-rays regarding these patients, there are published uh X-ray guidelines when evaluating the ankle, especially looking for deltoid ligament or high ankle sprains. Um, you can see on the picture now, typically they're, you know, when we're doing ankle imaging, we're getting an AP view and a mortise view. These two directional changes do adjust the overlap of the distal tibia onto the fibula itself. So normally during this AP view, uh the recommendations would be at least more than 10 millimeters of overlap, um, or normally more than six to ten millimeters. I typically was taught about 50% of overlap, usually shows that there's no concern for distal um tibiofibul ligament injury. And then on the mortise view, there should be at least one millimeter of overlap. So if we look again, kind of looking at the spaces we're looking at. So the medial clear spaces we call it would be the space on the inside part where that talus and that distal tibia meet. That'd be evaluating if there's a possible injury to the deltoid ligament itself. We want that medial clear space again to be less than four millimeters. This is a mortise view, so we want that distal tibial overlap on the fibula to be at least one millimeter or more. And again, we don't want to see significant tilting on the talus here itself as well. And then when we're looking at the AP views, you could see here we want usually at least more than 10 millimeters. Some documentation shows six to ten millimeters of overlap at this distal tibular fibular space. Uh, and then again, at least less than four millimeters of clearance within this medial clear space. And then the distal, you know, space where that tibiofibular junction is at, as the clear space we call it there, should be less than five millimeters as well. So these are quick things that you can look at from an X-ray perspective to see if your X-rays meet any of these criteria.

Stress Views And Provocation Testing

SPEAKER_00 9:03

If it's a little bit ambiguous whether the X-rays show these changes or not, we can often do gravity stress views. It's questionable whether these add um diagnostic value, as um they're often dependent upon how the stress view is done. So when we're talking about these gravity stress views, we have the patient lie on their side. Um we put a little pad underneath their mid um calf area there, and we have gravity naturally pull the leg down and shooting that x-ray looking at that. And when we look at the x-ray itself, this is what it looks like. And the thought process is if there's an injury to the deltoid ligament, if there's a distal fibular fracture as there is with this x-ray, or there's an injury to the distal tibial fibular ligament, the ankle will naturally fall to gravity and open up that medial clear space, and we'll see more than four millimeters of movement in that medial clear space. And so some of the providers I work with do these gravity stress views regularly, some do not. One thing I was taught, you can mimic this specific uh movement while evaluating a patient and to see if there is an injury to this distal um tibiofibular ligament or syndismotic area. So oftentimes when I'm evaluating these patients, I will put them up into dorsiflexion and I will put, you know, do some forced extra rotation to kind of recreate the injury itself and see if this causes pain within the patient. And oftentimes this will cause increased pain in that distal tibiofibular junction, which is consistent with concerns for synismotic injury, and you can decide if you need these gravity stress fuse or possible an MRI at that time.

Why Dorsiflexion Makes It Worse

SPEAKER_00 10:49

When we look at the movement or the anatomy of the ankle joint itself, um, oftentimes you can see this movement with their planar flexion dorsiflexion activities. There is some natural slight inversion to the ankle itself. When we talk about anatomy, during dorsiflexion, the wider anterior talus engages the ankle mortise. Oftentimes the distal fibula externally rotates and translates proximally. During plinar flexion, the narrow posterior talus engages the ankle mortise. And during natural gait activities, the ankle mortise can fluctuate or widen approximately one millimeter. So that's why with this wider anterior talus and this forced andor dorsiflexed activity, this is why we see these injuries themselves. So again, when we look at dorsiflexion itself, you can see that when we dorsiflex, there's some slight external rotation, slight abduction of the ankle, um, causing that fluctuation in space between that distal tibular fibular junction, which leads to the most common mechanism for this injury and that forced dorsiflexion. So again, when we recreate this position and that full dorsiflex position, we're pushing that wider anterior aspect of the talus into the mortise itself and externally rotate, we can see if there's an injury to this distal tibiar fibular ligament.

MRI Proof And Common Associated Injuries

SPEAKER_00 12:20

So on this gentleman, we did get a gravity stress view. Um I don't think and would not say there's significant widening within this medial, approximately four to five millimeters, I think, when we measured it. We did end up getting an MRI to evaluate to see if there's a concern about injury to this anterior or posterior distal tibial fibular ligament. Um and so when we're looking at the axial images of the MRI, um here's our talus coming into the middle, our fibula out here, our distal tibia in here, and here's the posterior tibiofibular ligament here. And then as we scroll through, there's our anterior tibial fibriarculament. And you can see there's an injury to that complex. There's a complete tear within the anterior tibial fibrillar ligament itself. Now, a couple other parts of anatomy to look at. Um, when we're looking at the MRI from the axial views, you can see this here, and this is typically the transverse tibial fibrillar ligament. It sits superficial to the deeper posterior tibial fibrillar ligament, which is a bit more of a fan-like uh fashion, which you can see kind of on this view here. So the superficial transverse tibial fibrillament here, this deeper fan-like posterior tibial fibrillar ligament, and then coming in there itself. Uh, and then looking at the anterior aspect, this would be the anterior tibial fibular ligament we're looking at here. And you could see there's a complete disruption of that. You can see the tear and also kind of the radioopaque uh fluid collection in the area. When we're looking down, this is a great view here of the anterior tibiofibular ligament, uh, or talofibular ligament, I apologize. Um the ATFL you can see coming into the view right there. And so, again, when we look at our coronal images, um kind of scrolling through, uh, again, getting our bearings right here of anatomy. So this is our talus here, uh tibia here, fibula comes into the picture here. You can see kind of our deltoid ligament kind of connecting uh out on that medial aspect. Um, we can see some fluid collections kind of right in that distal tibiofibular junction. Um you can kind of see fluid collecting all the way through there. Um, and so typically that denotes that there's an injury directly to this tibiofibular ligament itself. Um sagittal views don't show us much. If we think there's an isolated posterior malleose fracture, we could see some injury to that itself. We could see some fluid collection within that distotibial fibular ligament junction. We could see our perineal tendons coming down, you know, here, so we could see if there's any concomitant injuries to those perineal tendons as well. These do have associated uh concomitant injuries that can happen with the um the injury itself. Uh if you look at the literature, 15 to 25% of the time you can get an osteochondrial defect. Up to 25% of the time, you can get an injury to these perineal tendons as well, that you can see on the MRI image here. And then ankle fractures, Weber type C, Weber B ankle fractures, and even fractures to the base of this fifth uh metatarsal can can uh be associated as well. And then some will have uh an injury to the anterior uh process of the calcaneus. Um, on this gentleman, we didn't really see it, but oftentimes I'll see a bruising injury to the dome of the talus as well. Uh, and that's usually where that chondral injury happens.

Tightrope Fixation And Recovery Timelines

SPEAKER_00 16:02

So for this gentleman, because he was a high-level wrestler, he really wanted to get back to wrestling activities, uh, we did recommend doing a repair. And so for him, we did a tight rope type fixation uh across that distotibular fibular junction uh to try to repair that. He also had an arthroscopy as well. And during the arthroscopy, just looking to see if there's any concerns or injuries to um the articular surfaces, which um you can see here, um, there's no direct injuries to those. Sorry, trying to get my there you go, no direct injuries to those tailor surfaces um themselves. The the domain talus and distal tibia all looked okay. Um so no evidence of chondral defects or chondral damage. Was able to do the tight rub type fixation um and then follow the normal post-operative protocol for that. Usually the protocol for that would be uh non-weight bearing uh for six uh to possibly twelve weeks post-operatively, um, especially if there's a screw fixation. With type of fixation, usually there's not a concern about breaking. So usually about six to eight weeks will allow for progressive weight bearing and then increases weight bearing every two weeks after that, start range of motion and physical therapy activities. If we're treating this conservatively non-surgically, typically we're gonna put these in a cam walking boot, um, usually for and have them non-weight bearing for three to four weeks. Um if it's just a sprain without the diastasis or ankle instability, typically we can get away with these non-operative um alternatives. Uh, usually delayed weight bearing can allow for um quicker recovery and usually um prevent the prolonged um and high variability of recovery that is often seen with these high ankle sprains. If you've ever seen these patients come into clinic, they can um andor seen um evaluations uh andor athletes, um, they can take quite a long time. I mean, you know, anytime I see a football presentation and they say high ankle sprain, you know that that that football player's out basically the rest of the year. It takes them three to four months to recover. So we tend to try to treat these a little bit aggressively off the top. Um, some doctors will do cast immobilization for two to three weeks, some will do boot, um, wear the boot basically at all times for two to three weeks, um limited and or no weight bearing. Um and then as they progress after that with followed-up x-ray images, they can do some progressive weight-bearing activities.

Closing Thoughts And Feedback Request

SPEAKER_00 18:52

I hope you enjoyed this presentation. Again, this was uh interesting case. I saw, I feel like three or four of these come in uh at a relatively uh the same time. Um two were wrestlers and one um uh was landing a long jump and he was in that forced dorsiflex position, but because he landed in the sand, he had a forced e-version. Um and again, when I hear those things in my head, I think concerns for high ankle sprains because I know the kinesthetics of the ankle, as we showed you, and you know, when we're in that dorsiflex position, that wider anterior aspect of the talus often puts more stress on that syndismosis itself. Um, again, I hope you enjoyed this. Uh hopefully we'll have some more case presentations. If you like this, please give us feedback. Um, I like the interactive nature of these presentations to allow you to see the images that I'm looking at as well. Uh, have a great day. Thank you.