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Speaker: Next speaker is going to tell us a thing or two about peroneal tendons and what to do of them. Someone I think I know something a little bit about this guy. Kevin Jules is a chief of surgery at the college and my partner in private practice, so I know all the secrets. But he is going to give us a real good talk now, I know, on peroneal tendons.
Kevin Jules: Thanks Mike. Okay, first of all I have no disclosures. Alright. We are going to try to do today as you can see my objective and I hope when you leave here today, you will have a higher index of suspicion when you see patients who have lateral hindfoot and ankle pain and have a greater focus on assessing the peroneal tendons. So you are going to find that. When we take a look at the peroneal tendons, there seems to be a pretty broad spectrum of overlap of conditions that can occur simultaneously and I think many times are overlooked and lot of times they are not recognized and many times confused with other lateral hindfoot pain or ligamentous type injury. So I think it's definitely an under-appreciated source of lateral hindfoot pain and dysfunction and that's why I think it is a good idea to take a look at it. When we look at the literature, and you look about peroneal tendon disorder, you are going to see this group of foot and ankle people who seem to be the most published on things that go on with the peroneal tendons. Just back in paper a long time ago, Don Beck in a publication in 2003 that he showed that only 60% of 40 peroneal tendon disorders are accurately diagnosed at the first clinical evaluation. So what does that tell you that many times we are missing the boat. Okay, we are not taking a look for it or the diagnosis isn't made. And when you take a look at the literature, when you put lectures together and you are involved in academics, it's pulling every article there is about peroneal tendon disorders, a lot of the series are retrospective series and case reports.
And there is really no good level 1 or level 2 reports to support any type of treatment recommendations. So as many things that we do, there isn't lot out there that kind of guides us when we think about peroneal tendons and what is the best way to approach them. Another pretty interesting article by Mariam [phonetic] in Journal of Foot and Ankle Surgery more recent in 2015 spoke about peroneal tendon dislocations and the prevalence of the low lying peroneus brevis muscle belly as being the primary source of that happening. And she had the data of 50 patients retrospective study. They looked at 31 cases of low lying muscle belly and what's interesting is that many times and we had a nice talk about the MRI earlier today in utilizing that but many times they are overlooked that they don't show up on an MRI, which you thought something like that was talked about later creating that crowding effect would be readily seen on the MRI but it can be missed. Just to give you an example on this picture you're seeing on the bottom, this is a recent case of doing some repair of an anterior talofibular ligament then making a decision then and it wasn't on the MRI preoperatively that there was a low-lying muscle belly. So the entities that I really want to talk about specifically is that peroneal tendons subluxation and dislocation. We will talk about tears and then we will talk about that enlarged or hypertrophied peroneal tubercle and the os perineum and you will see there is going to be pretty decent overlap of these occurring together. So just take a look at those video. You can see, hopefully you understand that's not normal. You can see that the peroneal tendon with you being dorsiflexion, inversion or eversion is mounting from posterior to anterior over the lateral malleolus.
In this case, a lot of time we will say that lot of times these are habitual things that people come in not even knowing that's an abnormal entity and they come in with some type of hindfoot pain. When we think about the anatomy in that location, even before we get into the diagnosis and imaging, what went wrong is the reticulum that's torn. Is there -- was there trauma previously there or is it something that's habitual? People have this habitually as well. So you are going to see. There is another on the bottom here just to have this habitual type subluxation that can have those kinds of voluntary snapping. Sometimes they are asymptomatic. They want to come in and they want to know why they have this but it's not painful. Early on, it can result in -- you can see you can hear that click even from right open the outside of the ankle. We may diagnose it as being like a tenosynovitis or maybe associate it with some type of tenosynovitis. And in most cases, you are going to see with these people it can be a precursor for them to getting a longitudinal tear of the brevis as we know the brevis is anatomically closer to the malleolus. That's the thing that will mount from posterior to anterior. Or it was just some people have a superior peroneal retinaculum type insufficiency. So first talking about subluxation dislocation. We are going to talk about anatomical anomalies that can be a causative factor in having peroneal tendon subluxed. We are going to talk about shallow retrofibular groove, the crowding effect that occurs from the low lying peroneal brevis muscle belly, accessory peroneus quartus muscle, laxity of the retinaculum itself. Many times, it can be associated with lateral ankle instability from acute or chronic trauma, calcaneal valgus deformity or even cavus type foot as well.
So shallow retrofibular groove. When we think about that, it's a very hard diagnosis to make and as a matter of fact when the VS radiologist when you look in the literature now it says that you probably the only real way to find is to do an axial CT or an MRI with an anatomic shape and they can do this what's referred to as a real time kinematic MRI to try to help make that diagnosis. So when you think about the retrofibular groove, the sulcus itself is normally about 6 to 7 mm in width, 2 to 4 mm in depth and that shape of the groove is really determined by that posterior cartilaginous ridge that occurs. And Heckman [phonetic] 06:45] when you look at people who have studied this, he did a cadaveric assessment of the groove itself and he found that it was 82% were concave, 11% flat and 7% convex. So they are not all the same and usually when you have an abnormal groove, you end up getting some type of attrition that occurs with the peroneus brevis muscle itself. So what do you do for it? This can be --- if that's one of the reasons that the patient can have a subluxing peroneal tendon even that tendon tear with associated subluxation, two different groove deepening type techniques, intramedullary drilling with impaction and an old standard way of this periosteal type flap is utilized. So I will show you both of those. A groove deepening is essentially removing some of the medullary content from inside the fibula usually with straight forward drill bit. This was first published in Italian Orthopedic Foot and Ankle literature and I am just showing you and what you are looking up appear --when they did it they just did it freehand with a drill bit, but not many people recognized that as we know from trying to even fixate Jones fracture sometimes is very difficult to get into that medullary canal.
So we do with guide pins, so it's just really from like a cannulated screw type set. Then after that you can do with fluoro to take multiple views to make sure you are in the center of the fibula itself and then you are going to drill up into the medullary canal and then after drilling you could see top and bottom. After drilling, you can increase the drill size to try to make it deeper and to enhance the deepening itself. Then after that, this shows you with the pin right of the medullary canal, the tendons out of the way. Graduated drilling usually starts with like a smaller 2.0 drill up to 3.5 and then you are going to tamp it. You are not going to do anything to the osteal or periosteal flap in that location. So you remove the content from the fibula itself and then you use the little tamp to tamp it down. You are going to relocate the tendons, dorsiflexion, everted and then assess for the tendon to stay posterior. So here is just showing you when we are going from one stage to next and one is almost done. And you are going to see this occurs many times with a problem with the retinaculum itself and in conjunction with the shallow retrofibular groove. You need to just tamp this down with a mallet itself and a little tamp to create it. And you know eventually it's not an exact science from the standpoint of how much bone do you take out. It's a trial in the operating room. You drill, you tamp, you drill, you tamp and so you can keep the tendon posterior. And then the groove deepening. And then you can see here in this case, we tenodesed the brevis to the longus and we will talk about when you decide to do one of those versus just repairing the peroneal brevis tendon itself. You put a posterior dorsiflex and evert it and then you are going to see we can repair the retinaculum right back over the top of that again. People have talked about wrapping things around the tendon but there is no real good data to say that they are any better over the gliding functions, any better when doing this groove deepening with using any type of substance like that.
Again just to showing another freehand way of drilling right up to the medullary canal. I would say most people who do this type of thing now will use a cannulated system to make sure you stay central and don't break through the posterior cortex of it versus this was the old way before the intramedullary drilling. We will be doing or creating this osteal or periosteal flap where we dissect this up, take a curved bone gauze and remove some of the groove itself. When you review all the outcome data on using this type of technique, a lot more adhesions not as great gliding function of the peroneal tendons, so most people will do the other type of technique versus this osteal periosteal flap. So why do people get peroneal subluxation? Another thing that's associated where there is what's called this mass effect by having this low lying peroneus brevis muscle belly or the accessory muscle. And what it creates is a large crowding effect in the posterior aspect of the ankle and you get a subsequent stenosis of the retrofibular groove. It tears the superior peroneal retinculum and then the tendon will go from posterior to anterior. And really the surgical treatment for that is to really cauterize and remove the entire muscle belly from the brevis itself or having that accessory muscle. As I spoke about earlier, in most cases, you would like to able to identify that preoperatively by doing advanced imaging. But sometimes that's missed with advanced imaging. And you are going to see that the quartus muscle -- look at lower accessory of it, there is about 10% to 22% of the population does have this accessory muscle and they have higher incidences of having peroneal type tendon disorders versus people who have an acute type of injury. And as we know, in most cases it can be secondary to simple plantar flexion inversion injury. It's rare to get that mechanism before dorsiflexion and eversion.
And what happens is that there is some type of disruption or tearing of the superior peroneal retinaculum and you can see every time. Thatâs why every time when we see people who have lateral ankle pain or lateral ankle trauma, we take appropriate ankle views. In most cases if the retinaculum is torn, you will see that little flex sign where the retinaculum torn over the posterior aspect of the fibula itself. Just like everything we have, people try to classify things to take a look at different type of peroneal retinacular injuries where type 1 being probably the most common where there is just an elevation of the attachment of the retinaculum itself and then the tendons sit simply like an a pouch themselves, go from posterior to anterior and we will talk about how to fix that where they have been classified. In type 3 itself, usually occurring from acute plantar flexion type inversion injury and you will get that flex sign. So when people come in with lateral ankle trauma or plantar flexion inversion injuries, taking those ankle views that's one of the things we should be assessing from the standpoint of not missing the diagnosis of a torn retinaculum and then resulting in a subluxation. Retinacular tear, the treatment is to obviously repair it no matter what grade is from 1 to 4 and depending upon the condition of the retinaculum, a direct like pants-over-vest type repair versus if it's sometimes it's tethered you are going to see on the other side as showing you anchoring it back down to the fibula itself and removing scar tissue from that area. So two different ways have been described. So repair of retinaculum or anatomic reattachment back down to the fibula itself and in some cases when those of you have seen this intraoperatively sometimes there is like no tissue to repair whatsoever. Then you have to go to some type of alternate treatment like local tissue transfer as you see here taking a piece of the longus splitting it longitudinally, wrapping it around the brevis and showing it back on itself.
And also, there has been other bone block type procedures described for doing osteotomies of the fibula to reposition it to hold it back in a correct anatomic position. I don't have any experience of doing that just to use local tissue transfer of direct anatomic repair of that. From standpoint of peroneal tendons tearing, we take a look at theoretical rupture zone that are most common as you can see -- obviously the peroneus longus itself usually occurs distal to the malleolus, the brevis right from behind the malleolus and there has been some recent in anatomy journals taking a look at these "avascular zones" and it has not been recertified saying that the peroneal tendons really have these areas of avascularity when they run on the posterior aspect of the fibula versus the posterior tibial tendon which they still do. So it may not be the reason that people get a rupture because of an avascular area. But of course on all of these, we are going to get some type of advanced imaging to try to get a good idea of where it's torn and the percentage of tear and planning some type of operative intervention. The brevis is obviously the most common because it's directed behind the malleolus. It can occur with a simple acute plantar flexion inversion injury. People can also get it who have chronic lateral ankle instability and the tendon going from posterior to anterior and of course it creates that stenosis in that retrofibular groove because it could be secondary again to that mass effect and all of them of the brevis tears predominantly or longitudinal tears. You can see in the little schematic on your bottom right the tendon itself goes over that cartilaginous ridge and it splits longitudinally.
Like we all do if you are very good at high resolution also sonography, probably you could help make the diagnosis with that. I think that has as pretty high learning curve. In most cases, people resort to getting in an MRI and as a radiologist we are going to do the MRI now and like a dorsiflexed position to eliminate, I am sure you have heard of that magic angle effect because we used to, if it wasn't taken with the ankle held at 90 degrees, you could believe that there was a longitudinal tear of the tendon and intraoperative wouldn't be there. But the point is most of these cases you have to have advanced imaging from the standpoint of document that you do have a longitudinal tear and hopefully maybe even the percentage of how much the tendon is torn because it's going to make a difference what you are going to do in the operating room. For the brevis, it's obviously retromalleolar sulcus that occurs. It's proximal to the styloid itself. Look at it, in literature it has been graded by this guy, Soble, probably has done the most publication on peroneal tendon pathology. But I have a tendency to like this Krause and Brodsky type of classification system simply because it's a lot easier. When you open these up as you know many times you will look at an MRI and you will notice a change in the signal intensity that will give you an idea of how much the tendon is torn. When you go to look at it, it's hard to really assess that intraoperatively. Usually, it's many times calcified. You won't see the normal longitudinal appearance that the tendon does. So most of these cases, it's complete debridement of the tendon and when it gets greater than 50% of debridement of the brevis, then it's recommended that you should be transferring or tenodesing it to the longus tendon. So greater than 50%, usually the patients don't do well. They can get a recurrence or retear of the tendon. So you are going to sew it side to side to the longus tendon right at the level of the malleolus itself versus Soble did -- essentially if you go through this whole classification system, really comes down to being the same thing depending upon how much debridement is going to dictate whether you are going to do a transfer or not a tenodesis to the longus itself.
Of course, it's just tubularizing of the tendon. Some recent publications have come out of Lantern, different techniques of sewing a tendon, but I would say the standard way that most people do is after debriding would be to use some type of non-resorbable tubularization of the tendon itself. Just to show you here, you can see on the top left, that's one that was greater than 50%, so sewing it to the longus, repairing the retinaculum may be doing the groove, it can overlap in all cases. Another one on the top right, the same thing. Sewing it side to side to the longus again because of greater than 50% tear of tendon. And then some rare-rare instances as you can see on the bottom right that you can get someone who has almost a complete tear of the tendon where you have to debride out a complete section. Then you might be thinking about grafting the tendon but it's rare. Usually, the mostly longitudinal is rare that you are going to get a transverse tear of the tendon. The next thing we are going to talk about is the hypertrophied peroneal tubercle. I am sure all of you who sat there right now, you could all put your index finger on your lateral calcaneus and be able to palpate your peroneal tubercle. When you look at the literature, we always see, being a foot and ankle specialist that everyone has it. But it being enlarged as an instance when you study everything 36% to 97% and the pain is most commonly associated with people getting peroneus longus tenosynovitis or longitudinal rupture of the tubercle itself. It's rare but in some isolated case is seen with the brevis. In most cases, it goes along with having some type of peroneus longus pathology. You can see here clinically exactly where it's located.
When you look at all the literature about these peroneal tubercles from the standpoint, yes, it's pretty easy to make the diagnosis, you can palpate it. Lot of times we may treat it conservatively. You can give steroid shots for tenosynovitis, but then when that fails, what do you do with it? And if you are going to take it out, can you take the whole thing out? And what's the criteria for that? I have studied it all the stuff and there isn't really consensus statement to say you take out if it's this many millimeters, just how much bone you take out. As a matter of fact, I will tell you the bottom line is removing the entire tubercle. So here you can see an MRI and then showing you that there is some inflammation of the longus, a large tubercle there. Here is some who had an 8-mm peroneal tubercle. Normally, the 3 or 4-mm themselves, so this is somewhat double the size with associated peroneus longus tenosynovitis and remember that normal tubercle has like a cartilaginous gliding surface. You may say if I remove that, what happens to the peroneus longus? Is it going to grind into the cancellous bone on the lateral aspect of the calcaneus? Can you try just to remove part of it and get it down to three? The bottom line is when you look at everything that has been published on doing this is to remove the entire tubercle. Outcome wise, it doesn't seem to effect what happens to the pole of peroneus longus. So it's just to show you intraoperatively here. You can see that's obviously the longus on the bottom, brevis on the top and the large tubercle on the middle. And you are going to -- this had a video too. As you can see it has cartilaginous facet and what happens -- it's supposed to help in assisting the peroneus longus to glide over as it does towards the cuboid. And usually, when you look at the literature that said people who have one larger than 5 mm usually are the most common to have symptoms and lateral hindfoot as well as developing peroneus longus tear.
So just I am going to show you intraoperative. That was a video that didn't go off. I am showing you going up and down. Then after you take the tubercle out, of course you have assessed the peroneus longus. Many times, it has longitudinal tears, so you are going to have to debride away the tenosynovitis. And then what do you do from the lateral wall of the calcaneus. There is no clear guideline for that. Years ago, we thought about, up here, I took a little fat graft from the posterior triangle, put that on to the peroneal tendon. Suggestions like that although I don't think it really makes any difference up to putting bone wax to prevent it or doing nothing. So the bottom line is to just an aggressive resection of the tubercle itself, assessing the peroneus longus preoperatively where there is a longitudinal tear and having to repair that at the same time. The other peroneal tendon thing is os peroneum or referred as -- Soble refers to it as the os peroneum syndrome. The os peroneum themselves is like a sesamoid bone within the longus itself, which cuts off and goes across the interior aspect of the cuboid. These things are very, very difficult to manage when they fracture. The size of them is very, very variable. They have a high instance of non-healing and if painful, it can be associated with a rupture of the peroneus longus tendon as well as a nonunion of the os peroneum itself. So remember that sesamoid bone lies within the tendon like every sesamoid bone. When you look in literature, prevalence of this is really unknown. We are obviously much more tuned to it. It seems to me the literature supports visible and about 20% of all foot x-rays but we look at foot x-rays everyday it seems that most people have it.
Of course, MRI signal is more cartilaginous, very minimal medullary content to it. And any time you see one of these os peroneum is proximal. It's very commonly associated with a tear of the peroneus longus tendon itself. And usually of course, when you look at it how do you diagnose it? In most cases, it's by simple palpation. There is pain right over at the cuboid itself. Patients will say that it's exacerbated when they do like a little heel rise or more pain at the calcaneal cuboid joint itself. You can see here many times like some sesamoid bones it can fractured. We can see that there can be multipartite and sometimes irritating to the longus itself. You see on the right hand side, if you see proximal migration of the sesamoid bone like that you can be pretty sure that there is a tear at the peroneus longus tendon itself. So just as given you when you look at the literature from the standpoint of how bigger they are supposed to be, there is no guidelines. There are different sizes, there are different shapes. You can see a very minor one in the middle, bipartite or fractured one on that side and seemingly a normal appearing of on the top right there. So the solution for this if it's painful and associated with any type of tendon injury is to remove the sesamoid. So it's going to be a shelling out of the os peroneum from the peroneus longus and obviously right by the cuboid. Based on preoperative imaging, we will determine whether you have to do something to the longus itself. But as we all know, because it's in the tendon itself when we go to shell it out, in most cases there is some type of -- we create some damage to the longus itself. In many cases, it's going to go on to having some type of repair of the tendon intraoperatively.
Like everything we try to do this in a smallest incision possible. It seems like I do fluoroscopy just about everything now. But planning an incision, making sure in the exact location. As you know sural nerve runs right over that area. So we got to worry about sural nerve irritation. So simple dissection down to the fascia, down to the tendon. As with all the sesamoids, it usually appears a little bit bigger when you shell it out of the peroneus longus itself. Then you should be inspecting the tendon or have an idea preoperatively that you are going to pop half to repair that or to tubularize that as well. So you can see the top right after removing it repairing the longus or tubularizing that again. It's rare that you have to transfer, usually doesn't involve and it's a longitudinal tear. It's usually doesn't involve any type of transfer because usually it's not enough that requires any type of transfer or tendon grafting. So just showing on the bottom fluoro making sure you are in the right location and removing it into substance. Afterwards immobilization, usually three to four weeks and then obviously back on to some type of therapy afterwards, really pretty much normal tendon healing but fairly simple surgery to do but of course having a high index suspicion of making the diagnosis. So I think about peroneal tendon locations, as you know now with arthroscopy and peroneal tendoscopy, now people are trying to do peroneal tendon surgery through scopes and stuff like that. I don't have any real -- just observed this and done this in an anatomy lab, but I think this is where things are headed from the standpoint of treating peroneal tendon disorder in a minimally invasive way and that's probably what's headed in the future. So peroneal tendon disorder, definitely a major source of lateral hindfoot pain and dysfunction.
I think that you have to make sure when you are taking a good history and physical that people of lateral ankle, foot and ankle pain that you've done good justice to examining or assessing the peroneal tendons, of course getting the appropriate imaging but most of all having a high clinical index of suspicion that is pathology associated with the peroneal tendons. Thank you.
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